[dev.typeparams] merge master into dev.typeparams

Change-Id: Ib2a0f85e00a7366b784e3615366ca3bde4ec8c49

doc/go1.16.html

@@ -38,6 +38,17 @@ Do not send CLs removing the interior tags from such phrases.
   <code>netbsd/arm64</code> port).
 </p>
 
+<h3 id="386">386</h3>
+
+<p><!-- golang.org/issue/40255, golang.org/issue/41848, CL 258957, and CL 260017 -->
+  As <a href="go1.15#386">announced</a> in the Go 1.15 release notes,
+  Go 1.16 drops support for x87 mode compilation (<code>GO386=387</code>).
+  Support for non-SSE2 processors is now available using soft float
+  mode (<code>GO386=softfloat</code>).
+  Users running on non-SSE2 processors should replace <code>GO386=387</code>
+  with <code>GO386=softfloat</code>.
+</p>
+
 <h2 id="tools">Tools</h2>
 
 <p>
@@ -162,6 +173,8 @@ Do not send CLs removing the interior tags from such phrases.
   TODO: update with final numbers later in the release.
 </p>
 
+<!-- CL 255259: https://golang.org/cl/255259: cmd/link: enable ASLR on windows binaries built with -buildmode=c-shared -->
+
 <h2 id="library">Core library</h2>
 
 <p>
@@ -200,6 +213,14 @@ Do not send CLs removing the interior tags from such phrases.
   with <code>"use of closed network connection"</code>.
 </p>
 
+<h3 id="reflect"><a href="/pkg/reflect/">reflect</a></h3>
+
+<p><!-- CL 259237, golang.org/issue/22075 -->
+  For interface types and values, <a href="/pkg/reflect/#Value.Method">Method</a>,
+  <a href="/pkg/reflect/#Value.MethodByName">MethodByName</a>, and
+  <a href="/pkg/reflect/#Value.NumMethod">NumMethod</a> now
+  operate on the interface's exported method set, rather than its full method set.
+</p>
 
 <h3 id="text/template/parse"><a href="/pkg/text/template/parse/">text/template/parse</a></h3>
 
@@ -273,5 +294,18 @@ Do not send CLs removing the interior tags from such phrases.
      of the form <code>"Range": "bytes=--N"</code> where <code>"-N"</code> is a negative suffix length, for
      example <code>"Range": "bytes=--2"</code>. It now replies with a <code>416 "Range Not Satisfiable"</code> response.
     </p>
+
+    <p><!-- CL 256498, golang.org/issue/36990 -->
+    Cookies set with <code>SameSiteDefaultMode</code> now behave according to the current
+    spec (no attribute is set) instead of generating a SameSite key without a value.
+    </p>
   </dd>
 </dl><!-- net/http -->
+
+<dl id="runtime/debug"><dt><a href="/pkg/runtime/debug/">runtime/debug</a></dt>
+  <dd>
+    <p><!-- CL 249677 -->
+      TODO: <a href="https://golang.org/cl/249677">https://golang.org/cl/249677</a>: provide Addr method for errors from SetPanicOnFault
+    </p>
+  </dd>
+</dl><!-- runtime/debug -->

doc/install-source.html

@@ -666,16 +666,13 @@ For example, you should not set <code>$GOHOSTARCH</code> to
 <code>arm</code> on an x86 system.
 </p>
 
-<li><code>$GO386</code> (for <code>386</code> only, default is auto-detected
+<li><code>$GO386</code> (for <code>386</code> only, defaults to <code>sse2</code>)
-if built on either <code>386</code> or <code>amd64</code>, <code>387</code> otherwise)
 <p>
-This controls the code generated by gc to use either the 387 floating-point unit
+This variable controls how gc implements floating point computations.
-(set to <code>387</code>) or SSE2 instructions (set to <code>sse2</code>) for
-floating point computations.
 </p>
 <ul>
-	<li><code>GO386=387</code>: use x87 for floating point operations; should support all x86 chips (Pentium MMX or later).</li>
+	<li><code>GO386=softfloat</code>: use software floating point operations; should support all x86 chips (Pentium MMX or later).</li>
-	<li><code>GO386=sse2</code>: use SSE2 for floating point operations; has better performance than 387, but only available on Pentium 4/Opteron/Athlon 64 or later.</li>
+	<li><code>GO386=sse2</code>: use SSE2 for floating point operations; has better performance but only available on Pentium 4/Opteron/Athlon 64 or later.</li>
 </ul>
 </li>
 

misc/cgo/test/sigaltstack.go

@@ -62,7 +62,7 @@ import (
 
 func testSigaltstack(t *testing.T) {
 	switch {
-	case runtime.GOOS == "solaris", runtime.GOOS == "illumos", (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && runtime.GOARCH == "arm64":
+	case runtime.GOOS == "solaris", runtime.GOOS == "illumos", runtime.GOOS == "ios" && runtime.GOARCH == "arm64":
 		t.Skipf("switching signal stack not implemented on %s/%s", runtime.GOOS, runtime.GOARCH)
 	}
 

misc/cgo/testcarchive/carchive_test.go

@@ -603,7 +603,7 @@ func TestExtar(t *testing.T) {
 	if runtime.Compiler == "gccgo" {
 		t.Skip("skipping -extar test when using gccgo")
 	}
-	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && runtime.GOARCH == "arm64" {
+	if runtime.GOOS == "ios" {
 		t.Skip("shell scripts are not executable on iOS hosts")
 	}
 

src/cmd/asm/internal/asm/testdata/arm64.s

@@ -81,6 +81,8 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	SHA512H2	V4.D2, V3, V2           // 628464ce
 	SHA512SU0	V9.D2, V8.D2            // 2881c0ce
 	SHA512SU1	V7.D2, V6.D2, V5.D2     // c58867ce
+	VRAX1	V26.D2, V29.D2, V30.D2          // be8f7ace
+	VXAR	$63, V27.D2, V21.D2, V26.D2     // bafe9bce
 	VADDV	V0.S4, V0                       // 00b8b14e
 	VMOVI	$82, V0.B16                     // 40e6024f
 	VUADDLV	V6.B16, V6                      // c638306e
@@ -139,6 +141,8 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	VTBL	V14.B16, [V3.B16, V4.B16, V5.B16], V17.B16                              // 71400e4e
 	VTBL	V13.B16, [V29.B16, V30.B16, V31.B16, V0.B16], V28.B16                   // bc630d4e
 	VTBL	V3.B8, [V27.B16], V8.B8                                                 // 6803030e
+	VEOR3	V2.B16, V7.B16, V12.B16, V25.B16                                        // 990907ce
+	VBCAX	V1.B16, V2.B16, V26.B16, V31.B16                                        // 5f0722ce
 	VZIP1	V16.H8, V3.H8, V19.H8           // 7338504e
 	VZIP2	V22.D2, V25.D2, V21.D2          // 357bd64e
 	VZIP1	V6.D2, V9.D2, V11.D2            // 2b39c64e

src/cmd/cgo/main.go

@@ -170,35 +170,51 @@ func usage() {
 
 var ptrSizeMap = map[string]int64{
 	"386":      4,
+	"alpha":    8,
 	"amd64":    8,
 	"arm":      4,
 	"arm64":    8,
+	"m68k":     4,
 	"mips":     4,
 	"mipsle":   4,
 	"mips64":   8,
 	"mips64le": 8,
+	"nios2":    4,
+	"ppc":      4,
 	"ppc64":    8,
 	"ppc64le":  8,
+	"riscv":    4,
 	"riscv64":  8,
 	"s390":     4,
 	"s390x":    8,
+	"sh":       4,
+	"shbe":     4,
+	"sparc":    4,
 	"sparc64":  8,
 }
 
 var intSizeMap = map[string]int64{
 	"386":      4,
+	"alpha":    8,
 	"amd64":    8,
 	"arm":      4,
 	"arm64":    8,
+	"m68k":     4,
 	"mips":     4,
 	"mipsle":   4,
 	"mips64":   8,
 	"mips64le": 8,
+	"nios2":    4,
+	"ppc":      4,
 	"ppc64":    8,
 	"ppc64le":  8,
+	"riscv":    4,
 	"riscv64":  8,
 	"s390":     4,
 	"s390x":    8,
+	"sh":       4,
+	"shbe":     4,
+	"sparc":    4,
 	"sparc64":  8,
 }
 

src/cmd/compile/internal/gc/bexport.go

@@ -126,30 +126,6 @@ const (
 	aliasTag
 )
 
-// untype returns the "pseudo" untyped type for a Ctype (import/export use only).
-// (we can't use a pre-initialized array because we must be sure all types are
-// set up)
-func untype(ctype Ctype) *types.Type {
-	switch ctype {
-	case CTINT:
-		return types.Idealint
-	case CTRUNE:
-		return types.Idealrune
-	case CTFLT:
-		return types.Idealfloat
-	case CTCPLX:
-		return types.Idealcomplex
-	case CTSTR:
-		return types.Idealstring
-	case CTBOOL:
-		return types.Idealbool
-	case CTNIL:
-		return types.Types[TNIL]
-	}
-	Fatalf("exporter: unknown Ctype")
-	return nil
-}
-
 var predecl []*types.Type // initialized lazily
 
 func predeclared() []*types.Type {
@@ -184,13 +160,13 @@ func predeclared() []*types.Type {
 			types.Errortype,
 
 			// untyped types
-			untype(CTBOOL),
+			types.UntypedBool,
-			untype(CTINT),
+			types.UntypedInt,
-			untype(CTRUNE),
+			types.UntypedRune,
-			untype(CTFLT),
+			types.UntypedFloat,
-			untype(CTCPLX),
+			types.UntypedComplex,
-			untype(CTSTR),
+			types.UntypedString,
-			untype(CTNIL),
+			types.Types[TNIL],
 
 			// package unsafe
 			types.Types[TUNSAFEPTR],

src/cmd/compile/internal/gc/const.go

@@ -1019,17 +1019,17 @@ func nodlit(v Val) *Node {
 func idealType(ct Ctype) *types.Type {
 	switch ct {
 	case CTSTR:
-		return types.Idealstring
+		return types.UntypedString
 	case CTBOOL:
-		return types.Idealbool
+		return types.UntypedBool
 	case CTINT:
-		return types.Idealint
+		return types.UntypedInt
 	case CTRUNE:
-		return types.Idealrune
+		return types.UntypedRune
 	case CTFLT:
-		return types.Idealfloat
+		return types.UntypedFloat
 	case CTCPLX:
-		return types.Idealcomplex
+		return types.UntypedComplex
 	case CTNIL:
 		return types.Types[TNIL]
 	}
@@ -1080,17 +1080,17 @@ func defaultlit2(l *Node, r *Node, force bool) (*Node, *Node) {
 
 func ctype(t *types.Type) Ctype {
 	switch t {
-	case types.Idealbool:
+	case types.UntypedBool:
 		return CTBOOL
-	case types.Idealstring:
+	case types.UntypedString:
 		return CTSTR
-	case types.Idealint:
+	case types.UntypedInt:
 		return CTINT
-	case types.Idealrune:
+	case types.UntypedRune:
 		return CTRUNE
-	case types.Idealfloat:
+	case types.UntypedFloat:
 		return CTFLT
-	case types.Idealcomplex:
+	case types.UntypedComplex:
 		return CTCPLX
 	}
 	Fatalf("bad type %v", t)
@@ -1111,17 +1111,17 @@ func defaultType(t *types.Type) *types.Type {
 	}
 
 	switch t {
-	case types.Idealbool:
+	case types.UntypedBool:
 		return types.Types[TBOOL]
-	case types.Idealstring:
+	case types.UntypedString:
 		return types.Types[TSTRING]
-	case types.Idealint:
+	case types.UntypedInt:
 		return types.Types[TINT]
-	case types.Idealrune:
+	case types.UntypedRune:
 		return types.Runetype
-	case types.Idealfloat:
+	case types.UntypedFloat:
 		return types.Types[TFLOAT64]
-	case types.Idealcomplex:
+	case types.UntypedComplex:
 		return types.Types[TCOMPLEX128]
 	}
 

src/cmd/compile/internal/gc/export.go

@@ -96,7 +96,7 @@ func importsym(ipkg *types.Pkg, s *types.Sym, op Op) *Node {
 	return n
 }
 
-// pkgtype returns the named type declared by symbol s.
+// importtype returns the named type declared by symbol s.
 // If no such type has been declared yet, a forward declaration is returned.
 // ipkg is the package being imported
 func importtype(ipkg *types.Pkg, pos src.XPos, s *types.Sym) *types.Type {

src/cmd/compile/internal/gc/fmt.go

@@ -773,17 +773,17 @@ func tconv2(b *bytes.Buffer, t *types.Type, flag FmtFlag, mode fmtMode, visited
 	if int(t.Etype) < len(basicnames) && basicnames[t.Etype] != "" {
 		var name string
 		switch t {
-		case types.Idealbool:
+		case types.UntypedBool:
 			name = "untyped bool"
-		case types.Idealstring:
+		case types.UntypedString:
 			name = "untyped string"
-		case types.Idealint:
+		case types.UntypedInt:
 			name = "untyped int"
-		case types.Idealrune:
+		case types.UntypedRune:
 			name = "untyped rune"
-		case types.Idealfloat:
+		case types.UntypedFloat:
 			name = "untyped float"
-		case types.Idealcomplex:
+		case types.UntypedComplex:
 			name = "untyped complex"
 		default:
 			name = basicnames[t.Etype]
@@ -1333,7 +1333,7 @@ func (n *Node) exprfmt(s fmt.State, prec int, mode fmtMode) {
 			n.Orig.exprfmt(s, prec, mode)
 			return
 		}
-		if n.Type != nil && n.Type.Etype != TIDEAL && n.Type.Etype != TNIL && n.Type != types.Idealbool && n.Type != types.Idealstring {
+		if n.Type != nil && n.Type.Etype != TIDEAL && n.Type.Etype != TNIL && n.Type != types.UntypedBool && n.Type != types.UntypedString {
 			// Need parens when type begins with what might
 			// be misinterpreted as a unary operator: * or <-.
 			if n.Type.IsPtr() || (n.Type.IsChan() && n.Type.ChanDir() == types.Crecv) {

src/cmd/compile/internal/gc/iexport.go

@@ -751,11 +751,11 @@ func (w *exportWriter) param(f *types.Field) {
 
 func constTypeOf(typ *types.Type) Ctype {
 	switch typ {
-	case types.Idealint, types.Idealrune:
+	case types.UntypedInt, types.UntypedRune:
 		return CTINT
-	case types.Idealfloat:
+	case types.UntypedFloat:
 		return CTFLT
-	case types.Idealcomplex:
+	case types.UntypedComplex:
 		return CTCPLX
 	}
 
@@ -780,8 +780,8 @@ func constTypeOf(typ *types.Type) Ctype {
 }
 
 func (w *exportWriter) value(typ *types.Type, v Val) {
-	if typ.IsUntyped() {
+	if vt := idealType(v.Ctype()); typ.IsUntyped() && typ != vt {
-		typ = untype(v.Ctype())
+		Fatalf("exporter: untyped type mismatch, have: %v, want: %v", typ, vt)
 	}
 	w.typ(typ)
 

src/cmd/compile/internal/gc/iimport.go

@@ -375,7 +375,7 @@ func (p *importReader) value() (typ *types.Type, v Val) {
 		v.U = p.string()
 	case CTINT:
 		x := new(Mpint)
-		x.Rune = typ == types.Idealrune
+		x.Rune = typ == types.UntypedRune
 		p.mpint(&x.Val, typ)
 		v.U = x
 	case CTFLT:

src/cmd/compile/internal/gc/reflect.go

@@ -1275,8 +1275,9 @@ func dtypesym(t *types.Type) *obj.LSym {
 		}
 		ot = dgopkgpath(lsym, ot, tpkg)
 
+		xcount := sort.Search(n, func(i int) bool { return !types.IsExported(m[i].name.Name) })
 		ot = dsymptr(lsym, ot, lsym, ot+3*Widthptr+uncommonSize(t))
-		ot = duintptr(lsym, ot, uint64(n))
+		ot = duintptr(lsym, ot, uint64(xcount))
 		ot = duintptr(lsym, ot, uint64(n))
 		dataAdd := imethodSize() * n
 		ot = dextratype(lsym, ot, t, dataAdd)

src/cmd/compile/internal/gc/ssa.go

@@ -50,12 +50,10 @@ func initssaconfig() {
 	// Caching is disabled in the backend, so generating these here avoids allocations.
 	_ = types.NewPtr(types.Types[TINTER])                             // *interface{}
 	_ = types.NewPtr(types.NewPtr(types.Types[TSTRING]))              // **string
-	_ = types.NewPtr(types.NewPtr(types.Idealstring))                 // **string
 	_ = types.NewPtr(types.NewSlice(types.Types[TINTER]))             // *[]interface{}
 	_ = types.NewPtr(types.NewPtr(types.Bytetype))                    // **byte
 	_ = types.NewPtr(types.NewSlice(types.Bytetype))                  // *[]byte
 	_ = types.NewPtr(types.NewSlice(types.Types[TSTRING]))            // *[]string
-	_ = types.NewPtr(types.NewSlice(types.Idealstring))               // *[]string
 	_ = types.NewPtr(types.NewPtr(types.NewPtr(types.Types[TUINT8]))) // ***uint8
 	_ = types.NewPtr(types.Types[TINT16])                             // *int16
 	_ = types.NewPtr(types.Types[TINT64])                             // *int64
@@ -4251,6 +4249,7 @@ func (s *state) openDeferExit() {
 	s.lastDeferExit = deferExit
 	s.lastDeferCount = len(s.openDefers)
 	zeroval := s.constInt8(types.Types[TUINT8], 0)
+	testLateExpansion := ssa.LateCallExpansionEnabledWithin(s.f)
 	// Test for and run defers in reverse order
 	for i := len(s.openDefers) - 1; i >= 0; i-- {
 		r := s.openDefers[i]
@@ -4288,23 +4287,38 @@ func (s *state) openDeferExit() {
 		stksize := fn.Type.ArgWidth()
 		var ACArgs []ssa.Param
 		var ACResults []ssa.Param
+		var callArgs []*ssa.Value
 		if r.rcvr != nil {
 			// rcvr in case of OCALLINTER
 			v := s.load(r.rcvr.Type.Elem(), r.rcvr)
 			addr := s.constOffPtrSP(s.f.Config.Types.UintptrPtr, argStart)
 			ACArgs = append(ACArgs, ssa.Param{Type: types.Types[TUINTPTR], Offset: int32(argStart)})
-			s.store(types.Types[TUINTPTR], addr, v)
+			if testLateExpansion {
+				callArgs = append(callArgs, v)
+			} else {
+				s.store(types.Types[TUINTPTR], addr, v)
+			}
 		}
 		for j, argAddrVal := range r.argVals {
 			f := getParam(r.n, j)
 			pt := types.NewPtr(f.Type)
-			addr := s.constOffPtrSP(pt, argStart+f.Offset)
+			ACArgs = append(ACArgs, ssa.Param{Type: f.Type, Offset: int32(argStart + f.Offset)})
-			ACArgs = append(ACArgs, ssa.Param{Type: types.Types[TUINTPTR], Offset: int32(argStart + f.Offset)})
+			if testLateExpansion {
-			if !canSSAType(f.Type) {
+				var a *ssa.Value
-				s.move(f.Type, addr, argAddrVal)
+				if !canSSAType(f.Type) {
+					a = s.newValue2(ssa.OpDereference, f.Type, argAddrVal, s.mem())
+				} else {
+					a = s.load(f.Type, argAddrVal)
+				}
+				callArgs = append(callArgs, a)
 			} else {
-				argVal := s.load(f.Type, argAddrVal)
+				addr := s.constOffPtrSP(pt, argStart+f.Offset)
-				s.storeType(f.Type, addr, argVal, 0, false)
+				if !canSSAType(f.Type) {
+					s.move(f.Type, addr, argAddrVal)
+				} else {
+					argVal := s.load(f.Type, argAddrVal)
+					s.storeType(f.Type, addr, argVal, 0, false)
+				}
 			}
 		}
 		var call *ssa.Value
@@ -4312,13 +4326,31 @@ func (s *state) openDeferExit() {
 			v := s.load(r.closure.Type.Elem(), r.closure)
 			s.maybeNilCheckClosure(v, callDefer)
 			codeptr := s.rawLoad(types.Types[TUINTPTR], v)
-			call = s.newValue3A(ssa.OpClosureCall, types.TypeMem, ssa.ClosureAuxCall(ACArgs, ACResults), codeptr, v, s.mem())
+			aux := ssa.ClosureAuxCall(ACArgs, ACResults)
+			if testLateExpansion {
+				callArgs = append(callArgs, s.mem())
+				call = s.newValue2A(ssa.OpClosureLECall, aux.LateExpansionResultType(), aux, codeptr, v)
+				call.AddArgs(callArgs...)
+			} else {
+				call = s.newValue3A(ssa.OpClosureCall, types.TypeMem, aux, codeptr, v, s.mem())
+			}
 		} else {
-			// Do a static call if the original call was a static function or method
+			aux := ssa.StaticAuxCall(fn.Sym.Linksym(), ACArgs, ACResults)
-			call = s.newValue1A(ssa.OpStaticCall, types.TypeMem, ssa.StaticAuxCall(fn.Sym.Linksym(), ACArgs, ACResults), s.mem())
+			if testLateExpansion {
+				callArgs = append(callArgs, s.mem())
+				call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux)
+				call.AddArgs(callArgs...)
+			} else {
+				// Do a static call if the original call was a static function or method
+				call = s.newValue1A(ssa.OpStaticCall, types.TypeMem, aux, s.mem())
+			}
 		}
 		call.AuxInt = stksize
-		s.vars[&memVar] = call
+		if testLateExpansion {
+			s.vars[&memVar] = s.newValue1I(ssa.OpSelectN, types.TypeMem, int64(len(ACResults)), call)
+		} else {
+			s.vars[&memVar] = call
+		}
 		// Make sure that the stack slots with pointers are kept live
 		// through the call (which is a pre-emption point). Also, we will
 		// use the first call of the last defer exit to compute liveness
@@ -4375,9 +4407,7 @@ func (s *state) call(n *Node, k callKind, returnResultAddr bool) *ssa.Value {
 
 	switch n.Op {
 	case OCALLFUNC:
-		if k != callDeferStack && ssa.LateCallExpansionEnabledWithin(s.f) {
+		testLateExpansion = k != callDeferStack && ssa.LateCallExpansionEnabledWithin(s.f)
-			testLateExpansion = true
-		}
 		if k == callNormal && fn.Op == ONAME && fn.Class() == PFUNC {
 			sym = fn.Sym
 			break
@@ -4392,9 +4422,7 @@ func (s *state) call(n *Node, k callKind, returnResultAddr bool) *ssa.Value {
 		if fn.Op != ODOTMETH {
 			s.Fatalf("OCALLMETH: n.Left not an ODOTMETH: %v", fn)
 		}
-		if k != callDeferStack && ssa.LateCallExpansionEnabledWithin(s.f) {
+		testLateExpansion = k != callDeferStack && ssa.LateCallExpansionEnabledWithin(s.f)
-			testLateExpansion = true
-		}
 		if k == callNormal {
 			sym = fn.Sym
 			break
@@ -4406,9 +4434,7 @@ func (s *state) call(n *Node, k callKind, returnResultAddr bool) *ssa.Value {
 		if fn.Op != ODOTINTER {
 			s.Fatalf("OCALLINTER: n.Left not an ODOTINTER: %v", fn.Op)
 		}
-		if k != callDeferStack && ssa.LateCallExpansionEnabledWithin(s.f) {
+		testLateExpansion = k != callDeferStack && ssa.LateCallExpansionEnabledWithin(s.f)
-			testLateExpansion = true
-		}
 		var iclosure *ssa.Value
 		iclosure, rcvr = s.getClosureAndRcvr(fn)
 		if k == callNormal {
@@ -4427,6 +4453,7 @@ func (s *state) call(n *Node, k callKind, returnResultAddr bool) *ssa.Value {
 
 	var call *ssa.Value
 	if k == callDeferStack {
+		testLateExpansion = ssa.LateCallExpansionEnabledWithin(s.f)
 		// Make a defer struct d on the stack.
 		t := deferstruct(stksize)
 		d := tempAt(n.Pos, s.curfn, t)
@@ -4477,10 +4504,17 @@ func (s *state) call(n *Node, k callKind, returnResultAddr bool) *ssa.Value {
 		}
 
 		// Call runtime.deferprocStack with pointer to _defer record.
-		arg0 := s.constOffPtrSP(types.Types[TUINTPTR], Ctxt.FixedFrameSize())
-		s.store(types.Types[TUINTPTR], arg0, addr)
 		ACArgs = append(ACArgs, ssa.Param{Type: types.Types[TUINTPTR], Offset: int32(Ctxt.FixedFrameSize())})
-		call = s.newValue1A(ssa.OpStaticCall, types.TypeMem, ssa.StaticAuxCall(deferprocStack, ACArgs, ACResults), s.mem())
+		aux := ssa.StaticAuxCall(deferprocStack, ACArgs, ACResults)
+		if testLateExpansion {
+			callArgs = append(callArgs, addr, s.mem())
+			call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux)
+			call.AddArgs(callArgs...)
+		} else {
+			arg0 := s.constOffPtrSP(types.Types[TUINTPTR], Ctxt.FixedFrameSize())
+			s.store(types.Types[TUINTPTR], arg0, addr)
+			call = s.newValue1A(ssa.OpStaticCall, types.TypeMem, aux, s.mem())
+		}
 		if stksize < int64(Widthptr) {
 			// We need room for both the call to deferprocStack and the call to
 			// the deferred function.
@@ -5039,15 +5073,22 @@ func (s *state) rtcall(fn *obj.LSym, returns bool, results []*types.Type, args .
 	s.prevCall = nil
 	// Write args to the stack
 	off := Ctxt.FixedFrameSize()
+	testLateExpansion := ssa.LateCallExpansionEnabledWithin(s.f)
 	var ACArgs []ssa.Param
 	var ACResults []ssa.Param
+	var callArgs []*ssa.Value
+
 	for _, arg := range args {
 		t := arg.Type
 		off = Rnd(off, t.Alignment())
-		ptr := s.constOffPtrSP(t.PtrTo(), off)
 		size := t.Size()
 		ACArgs = append(ACArgs, ssa.Param{Type: t, Offset: int32(off)})
-		s.store(t, ptr, arg)
+		if testLateExpansion {
+			callArgs = append(callArgs, arg)
+		} else {
+			ptr := s.constOffPtrSP(t.PtrTo(), off)
+			s.store(t, ptr, arg)
+		}
 		off += size
 	}
 	off = Rnd(off, int64(Widthreg))
@@ -5061,8 +5102,17 @@ func (s *state) rtcall(fn *obj.LSym, returns bool, results []*types.Type, args .
 	}
 
 	// Issue call
-	call := s.newValue1A(ssa.OpStaticCall, types.TypeMem, ssa.StaticAuxCall(fn, ACArgs, ACResults), s.mem())
+	var call *ssa.Value
-	s.vars[&memVar] = call
+	aux := ssa.StaticAuxCall(fn, ACArgs, ACResults)
+	if testLateExpansion {
+		callArgs = append(callArgs, s.mem())
+		call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux)
+		call.AddArgs(callArgs...)
+		s.vars[&memVar] = s.newValue1I(ssa.OpSelectN, types.TypeMem, int64(len(ACResults)), call)
+	} else {
+		call = s.newValue1A(ssa.OpStaticCall, types.TypeMem, aux, s.mem())
+		s.vars[&memVar] = call
+	}
 
 	if !returns {
 		// Finish block
@@ -5078,11 +5128,24 @@ func (s *state) rtcall(fn *obj.LSym, returns bool, results []*types.Type, args .
 
 	// Load results
 	res := make([]*ssa.Value, len(results))
-	for i, t := range results {
+	if testLateExpansion {
-		off = Rnd(off, t.Alignment())
+		for i, t := range results {
-		ptr := s.constOffPtrSP(types.NewPtr(t), off)
+			off = Rnd(off, t.Alignment())
-		res[i] = s.load(t, ptr)
+			if canSSAType(t) {
-		off += t.Size()
+				res[i] = s.newValue1I(ssa.OpSelectN, t, int64(i), call)
+			} else {
+				addr := s.newValue1I(ssa.OpSelectNAddr, types.NewPtr(t), int64(i), call)
+				res[i] = s.rawLoad(t, addr)
+			}
+			off += t.Size()
+		}
+	} else {
+		for i, t := range results {
+			off = Rnd(off, t.Alignment())
+			ptr := s.constOffPtrSP(types.NewPtr(t), off)
+			res[i] = s.load(t, ptr)
+			off += t.Size()
+		}
 	}
 	off = Rnd(off, int64(Widthptr))
 

src/cmd/compile/internal/gc/subr.go

@@ -825,7 +825,7 @@ func assignconvfn(n *Node, t *types.Type, context func() string) *Node {
 
 	// Convert ideal bool from comparison to plain bool
 	// if the next step is non-bool (like interface{}).
-	if n.Type == types.Idealbool && !t.IsBoolean() {
+	if n.Type == types.UntypedBool && !t.IsBoolean() {
 		if n.Op == ONAME || n.Op == OLITERAL {
 			r := nod(OCONVNOP, n, nil)
 			r.Type = types.Types[TBOOL]

src/cmd/compile/internal/gc/swt.go

@@ -440,7 +440,7 @@ func (c *exprClause) test(exprname *Node) *Node {
 
 	// Optimize "switch true { ...}" and "switch false { ... }".
 	if Isconst(exprname, CTBOOL) && !c.lo.Type.IsInterface() {
-		if exprname.Val().U.(bool) {
+		if exprname.Bool() {
 			return c.lo
 		} else {
 			return nodl(c.pos, ONOT, c.lo, nil)

src/cmd/compile/internal/gc/typecheck.go

@@ -361,7 +361,7 @@ func typecheck1(n *Node, top int) (res *Node) {
 		ok |= ctxExpr
 
 		if n.Type == nil && n.Val().Ctype() == CTSTR {
-			n.Type = types.Idealstring
+			n.Type = types.UntypedString
 		}
 
 	case ONONAME:
@@ -623,8 +623,8 @@ func typecheck1(n *Node, top int) (res *Node) {
 			// no defaultlit for left
 			// the outer context gives the type
 			n.Type = l.Type
-			if (l.Type == types.Idealfloat || l.Type == types.Idealcomplex) && r.Op == OLITERAL {
+			if (l.Type == types.UntypedFloat || l.Type == types.UntypedComplex) && r.Op == OLITERAL {
-				n.Type = types.Idealint
+				n.Type = types.UntypedInt
 			}
 
 			break
@@ -777,7 +777,7 @@ func typecheck1(n *Node, top int) (res *Node) {
 
 		if iscmp[n.Op] {
 			evconst(n)
-			t = types.Idealbool
+			t = types.UntypedBool
 			if n.Op != OLITERAL {
 				l, r = defaultlit2(l, r, true)
 				n.Left = l
@@ -1458,7 +1458,7 @@ func typecheck1(n *Node, top int) (res *Node) {
 		// Determine result type.
 		switch t.Etype {
 		case TIDEAL:
-			n.Type = types.Idealfloat
+			n.Type = types.UntypedFloat
 		case TCOMPLEX64:
 			n.Type = types.Types[TFLOAT32]
 		case TCOMPLEX128:
@@ -1504,7 +1504,7 @@ func typecheck1(n *Node, top int) (res *Node) {
 			return n
 
 		case TIDEAL:
-			t = types.Idealcomplex
+			t = types.UntypedComplex
 
 		case TFLOAT32:
 			t = types.Types[TCOMPLEX64]
@@ -2724,9 +2724,9 @@ func errorDetails(nl Nodes, tstruct *types.Type, isddd bool) string {
 // e.g in error messages about wrong arguments to return.
 func sigrepr(t *types.Type, isddd bool) string {
 	switch t {
-	case types.Idealstring:
+	case types.UntypedString:
 		return "string"
-	case types.Idealbool:
+	case types.UntypedBool:
 		return "bool"
 	}
 

src/cmd/compile/internal/gc/universe.go

@@ -123,21 +123,21 @@ func lexinit() {
 		asNode(s2.Def).SetSubOp(s.op)
 	}
 
-	types.Idealstring = types.New(TSTRING)
+	types.UntypedString = types.New(TSTRING)
-	types.Idealbool = types.New(TBOOL)
+	types.UntypedBool = types.New(TBOOL)
 	types.Types[TANY] = types.New(TANY)
 
 	s := builtinpkg.Lookup("true")
 	s.Def = asTypesNode(nodbool(true))
 	asNode(s.Def).Sym = lookup("true")
 	asNode(s.Def).Name = new(Name)
-	asNode(s.Def).Type = types.Idealbool
+	asNode(s.Def).Type = types.UntypedBool
 
 	s = builtinpkg.Lookup("false")
 	s.Def = asTypesNode(nodbool(false))
 	asNode(s.Def).Sym = lookup("false")
 	asNode(s.Def).Name = new(Name)
-	asNode(s.Def).Type = types.Idealbool
+	asNode(s.Def).Type = types.UntypedBool
 
 	s = lookup("_")
 	s.Block = -100
@@ -351,7 +351,7 @@ func typeinit() {
 	sizeofString = Rnd(sliceLenOffset+int64(Widthptr), int64(Widthptr))
 
 	dowidth(types.Types[TSTRING])
-	dowidth(types.Idealstring)
+	dowidth(types.UntypedString)
 }
 
 func makeErrorInterface() *types.Type {

src/cmd/compile/internal/ssa/expand_calls.go

@@ -39,7 +39,9 @@ func expandCalls(f *Func) {
 		hiOffset = 4
 	}
 
-	pairTypes := func(et types.EType) (tHi, tLo *types.Type) {
+	// intPairTypes returns the pair of 32-bit int types needed to encode a 64-bit integer type on a target
+	// that has no 64-bit integer registers.
+	intPairTypes := func(et types.EType) (tHi, tLo *types.Type) {
 		tHi = tUint32
 		if et == types.TINT64 {
 			tHi = tInt32
@@ -147,8 +149,8 @@ func expandCalls(f *Func) {
 		}
 	}
 
-	// storeArg converts stores of SSA-able aggregates into a series of stores of smaller types into
+	// storeArg converts stores of SSA-able aggregate arguments (passed to a call) into a series of stores of
-	// individual parameter slots.
+	// smaller types into individual parameter slots.
 	// TODO when registers really arrive, must also decompose anything split across two registers or registers and memory.
 	var storeArg func(pos src.XPos, b *Block, a *Value, t *types.Type, offset int64, mem *Value) *Value
 	storeArg = func(pos src.XPos, b *Block, a *Value, t *types.Type, offset int64, mem *Value) *Value {
@@ -165,7 +167,7 @@ func expandCalls(f *Func) {
 			return storeArg(pos, b, a.Args[0], t.Elem(), offset, mem)
 
 		case OpInt64Make:
-			tHi, tLo := pairTypes(t.Etype)
+			tHi, tLo := intPairTypes(t.Etype)
 			mem = storeArg(pos, b, a.Args[0], tHi, offset+hiOffset, mem)
 			return storeArg(pos, b, a.Args[1], tLo, offset+lowOffset, mem)
 		}
@@ -207,7 +209,7 @@ func expandCalls(f *Func) {
 			if t.Width == regSize {
 				break
 			}
-			tHi, tLo := pairTypes(t.Etype)
+			tHi, tLo := intPairTypes(t.Etype)
 			sel := src.Block.NewValue1(pos, OpInt64Hi, tHi, src)
 			mem = splitStore(dst, sel, mem, v, tHi, offset+hiOffset, firstStorePos)
 			firstStorePos = firstStorePos.WithNotStmt()
@@ -261,6 +263,9 @@ func expandCalls(f *Func) {
 		return x
 	}
 
+	// rewriteArgs removes all the Args from a call and converts the call args into appropriate
+	// stores (or later, register movement).  Extra args for interface and closure calls are ignored,
+	// but removed.
 	rewriteArgs := func(v *Value, firstArg int) *Value {
 		// Thread the stores on the memory arg
 		aux := v.Aux.(*AuxCall)
@@ -283,7 +288,7 @@ func expandCalls(f *Func) {
 				// TODO this will be more complicated with registers in the picture.
 				src := a.Args[0]
 				dst := f.ConstOffPtrSP(src.Type, aux.OffsetOfArg(auxI), sp)
-				if a.Uses == 1 {
+				if a.Uses == 1 && a.Block == v.Block {
 					a.reset(OpMove)
 					a.Pos = pos
 					a.Type = types.TypeMem
@@ -292,7 +297,7 @@ func expandCalls(f *Func) {
 					a.SetArgs3(dst, src, mem)
 					mem = a
 				} else {
-					mem = a.Block.NewValue3A(pos, OpMove, types.TypeMem, aux.TypeOfArg(auxI), dst, src, mem)
+					mem = v.Block.NewValue3A(pos, OpMove, types.TypeMem, aux.TypeOfArg(auxI), dst, src, mem)
 					mem.AuxInt = aux.SizeOfArg(auxI)
 				}
 			} else {

src/cmd/compile/internal/ssa/func.go

@@ -672,7 +672,7 @@ func (f *Func) Idom() []*Block {
 	return f.cachedIdom
 }
 
-// sdom returns a sparse tree representing the dominator relationships
+// Sdom returns a sparse tree representing the dominator relationships
 // among the blocks of f.
 func (f *Func) Sdom() SparseTree {
 	if f.cachedSdom == nil {

src/cmd/compile/internal/ssa/gen/AMD64.rules

@@ -1274,8 +1274,8 @@
 (CMPQconst (ANDQconst _ [m]) [n]) && 0 <= m && m < n => (FlagLT_ULT)
 (CMPQconst (ANDLconst _ [m]) [n]) && 0 <= m && m < n => (FlagLT_ULT)
 (CMPLconst (ANDLconst _ [m]) [n]) && 0 <= m && m < n => (FlagLT_ULT)
-(CMPWconst (ANDLconst _ [m]) [n]) && 0 <= m && int16(m) < n => (FlagLT_ULT)
+(CMPWconst (ANDLconst _ [m]) [n]) && 0 <= int16(m) && int16(m) < n => (FlagLT_ULT)
-(CMPBconst (ANDLconst _ [m]) [n]) && 0 <= m && int8(m)  < n => (FlagLT_ULT)
+(CMPBconst (ANDLconst _ [m]) [n]) && 0 <= int8(m)  && int8(m)  < n => (FlagLT_ULT)
 
 // TESTQ c c sets flags like CMPQ c 0.
 (TESTQconst [c] (MOVQconst [d])) && int64(c) == d && c == 0 => (FlagEQ)

src/cmd/compile/internal/ssa/gen/genericOps.go

@@ -541,10 +541,10 @@ var genericOps = []opData{
 	{name: "SelectN", argLength: 1, aux: "Int64"},     // arg0=tuple, auxint=field index.  Returns the auxint'th member.
 	{name: "SelectNAddr", argLength: 1, aux: "Int64"}, // arg0=tuple, auxint=field index.  Returns the address of auxint'th member. Used for un-SSA-able result types.
 
-	// Atomic operations used for semantically inlining runtime/internal/atomic.
+	// Atomic operations used for semantically inlining sync/atomic and
-	// Atomic loads return a new memory so that the loads are properly ordered
+	// runtime/internal/atomic. Atomic loads return a new memory so that
-	// with respect to other loads and stores.
+	// the loads are properly ordered with respect to other loads and
-	// TODO: use for sync/atomic at some point.
+	// stores.
 	{name: "AtomicLoad8", argLength: 2, typ: "(UInt8,Mem)"},                                    // Load from arg0.  arg1=memory.  Returns loaded value and new memory.
 	{name: "AtomicLoad32", argLength: 2, typ: "(UInt32,Mem)"},                                  // Load from arg0.  arg1=memory.  Returns loaded value and new memory.
 	{name: "AtomicLoad64", argLength: 2, typ: "(UInt64,Mem)"},                                  // Load from arg0.  arg1=memory.  Returns loaded value and new memory.

src/cmd/compile/internal/ssa/rewriteAMD64.go

@@ -6886,7 +6886,7 @@ func rewriteValueAMD64_OpAMD64CMPBconst(v *Value) bool {
 		return true
 	}
 	// match: (CMPBconst (ANDLconst _ [m]) [n])
-	// cond: 0 <= m && int8(m) < n
+	// cond: 0 <= int8(m) && int8(m) < n
 	// result: (FlagLT_ULT)
 	for {
 		n := auxIntToInt8(v.AuxInt)
@@ -6894,7 +6894,7 @@ func rewriteValueAMD64_OpAMD64CMPBconst(v *Value) bool {
 			break
 		}
 		m := auxIntToInt32(v_0.AuxInt)
-		if !(0 <= m && int8(m) < n) {
+		if !(0 <= int8(m) && int8(m) < n) {
 			break
 		}
 		v.reset(OpAMD64FlagLT_ULT)
@@ -8243,7 +8243,7 @@ func rewriteValueAMD64_OpAMD64CMPWconst(v *Value) bool {
 		return true
 	}
 	// match: (CMPWconst (ANDLconst _ [m]) [n])
-	// cond: 0 <= m && int16(m) < n
+	// cond: 0 <= int16(m) && int16(m) < n
 	// result: (FlagLT_ULT)
 	for {
 		n := auxIntToInt16(v.AuxInt)
@@ -8251,7 +8251,7 @@ func rewriteValueAMD64_OpAMD64CMPWconst(v *Value) bool {
 			break
 		}
 		m := auxIntToInt32(v_0.AuxInt)
-		if !(0 <= m && int16(m) < n) {
+		if !(0 <= int16(m) && int16(m) < n) {
 			break
 		}
 		v.reset(OpAMD64FlagLT_ULT)

src/cmd/compile/internal/syntax/parser.go

@@ -287,6 +287,7 @@ func tokstring(tok token) string {
 
 // Convenience methods using the current token position.
 func (p *parser) pos() Pos               { return p.posAt(p.line, p.col) }
+func (p *parser) error(msg string)       { p.errorAt(p.pos(), msg) }
 func (p *parser) syntaxError(msg string) { p.syntaxErrorAt(p.pos(), msg) }
 
 // The stopset contains keywords that start a statement.
@@ -997,17 +998,20 @@ loop:
 				// x[i:j...
 				t.Index[1] = p.expr()
 			}
-			if p.got(_Colon) {
+			if p.tok == _Colon {
 				t.Full = true
 				// x[i:j:...]
 				if t.Index[1] == nil {
 					p.error("middle index required in 3-index slice")
+					t.Index[1] = p.badExpr()
 				}
+				p.next()
 				if p.tok != _Rbrack {
 					// x[i:j:k...
 					t.Index[2] = p.expr()
 				} else {
 					p.error("final index required in 3-index slice")
+					t.Index[2] = p.badExpr()
 				}
 			}
 			p.want(_Rbrack)
@@ -1836,6 +1840,7 @@ func (p *parser) header(keyword token) (init SimpleStmt, cond Expr, post SimpleS
 	if p.tok == _Lbrace {
 		if keyword == _If {
 			p.syntaxError("missing condition in if statement")
+			cond = p.badExpr()
 		}
 		return
 	}
@@ -1907,6 +1912,9 @@ done:
 			} else {
 				p.syntaxErrorAt(semi.pos, "missing condition in if statement")
 			}
+			b := new(BadExpr)
+			b.pos = semi.pos
+			cond = b
 		}
 	case *ExprStmt:
 		cond = s.X

src/cmd/compile/internal/types/type.go

@@ -105,14 +105,14 @@ var (
 	Errortype *Type
 
 	// Types to represent untyped string and boolean constants.
-	Idealstring *Type
+	UntypedString *Type
-	Idealbool   *Type
+	UntypedBool   *Type
 
 	// Types to represent untyped numeric constants.
-	Idealint     = New(TIDEAL)
+	UntypedInt     = New(TIDEAL)
-	Idealrune    = New(TIDEAL)
+	UntypedRune    = New(TIDEAL)
-	Idealfloat   = New(TIDEAL)
+	UntypedFloat   = New(TIDEAL)
-	Idealcomplex = New(TIDEAL)
+	UntypedComplex = New(TIDEAL)
 )
 
 // A Type represents a Go type.
@@ -1436,7 +1436,7 @@ func (t *Type) IsUntyped() bool {
 	if t == nil {
 		return false
 	}
-	if t == Idealstring || t == Idealbool {
+	if t == UntypedString || t == UntypedBool {
 		return true
 	}
 	switch t.Etype {

src/cmd/compile/internal/x86/galign.go

@@ -7,6 +7,9 @@ package x86
 import (
 	"cmd/compile/internal/gc"
 	"cmd/internal/obj/x86"
+	"cmd/internal/objabi"
+	"fmt"
+	"os"
 )
 
 func Init(arch *gc.Arch) {
@@ -15,6 +18,18 @@ func Init(arch *gc.Arch) {
 	arch.SSAGenValue = ssaGenValue
 	arch.SSAGenBlock = ssaGenBlock
 	arch.MAXWIDTH = (1 << 32) - 1
+	switch v := objabi.GO386; v {
+	case "sse2":
+	case "softfloat":
+		arch.SoftFloat = true
+	case "387":
+		fmt.Fprintf(os.Stderr, "unsupported setting GO386=387. Consider using GO386=softfloat instead.\n")
+		gc.Exit(1)
+	default:
+		fmt.Fprintf(os.Stderr, "unsupported setting GO386=%s\n", v)
+		gc.Exit(1)
+
+	}
 
 	arch.ZeroRange = zerorange
 	arch.Ginsnop = ginsnop

src/cmd/dist/build.go

@@ -30,6 +30,7 @@ var (
 	gohostos         string
 	goos             string
 	goarm            string
+	go386            string
 	gomips           string
 	gomips64         string
 	goppc64          string
@@ -141,6 +142,12 @@ func xinit() {
 	}
 	goarm = b
 
+	b = os.Getenv("GO386")
+	if b == "" {
+		b = "sse2"
+	}
+	go386 = b
+
 	b = os.Getenv("GOMIPS")
 	if b == "" {
 		b = "hardfloat"
@@ -212,6 +219,7 @@ func xinit() {
 	defaultldso = os.Getenv("GO_LDSO")
 
 	// For tools being invoked but also for os.ExpandEnv.
+	os.Setenv("GO386", go386)
 	os.Setenv("GOARCH", goarch)
 	os.Setenv("GOARM", goarm)
 	os.Setenv("GOHOSTARCH", gohostarch)
@@ -1153,6 +1161,9 @@ func cmdenv() {
 	if goarch == "arm" {
 		xprintf(format, "GOARM", goarm)
 	}
+	if goarch == "386" {
+		xprintf(format, "GO386", go386)
+	}
 	if goarch == "mips" || goarch == "mipsle" {
 		xprintf(format, "GOMIPS", gomips)
 	}

src/cmd/dist/buildruntime.go

@@ -41,6 +41,7 @@ func mkzversion(dir, file string) {
 //	package objabi
 //
 //	const defaultGOROOT = <goroot>
+//	const defaultGO386 = <go386>
 //	const defaultGOARM = <goarm>
 //	const defaultGOMIPS = <gomips>
 //	const defaultGOMIPS64 = <gomips64>
@@ -69,6 +70,7 @@ func mkzbootstrap(file string) {
 	fmt.Fprintln(&buf)
 	fmt.Fprintf(&buf, "import \"runtime\"\n")
 	fmt.Fprintln(&buf)
+	fmt.Fprintf(&buf, "const defaultGO386 = `%s`\n", go386)
 	fmt.Fprintf(&buf, "const defaultGOARM = `%s`\n", goarm)
 	fmt.Fprintf(&buf, "const defaultGOMIPS = `%s`\n", gomips)
 	fmt.Fprintf(&buf, "const defaultGOMIPS64 = `%s`\n", gomips64)

src/cmd/dist/test.go

@@ -903,7 +903,7 @@ func (t *tester) addCmd(dt *distTest, dir string, cmdline ...interface{}) *exec.
 }
 
 func (t *tester) iOS() bool {
-	return (goos == "darwin" || goos == "ios") && goarch == "arm64"
+	return goos == "ios"
 }
 
 func (t *tester) out(v string) {
@@ -992,7 +992,7 @@ func (t *tester) supportedBuildmode(mode string) bool {
 	case "c-shared":
 		switch pair {
 		case "linux-386", "linux-amd64", "linux-arm", "linux-arm64", "linux-ppc64le", "linux-s390x",
-			"darwin-amd64",
+			"darwin-amd64", "darwin-arm64",
 			"freebsd-amd64",
 			"android-arm", "android-arm64", "android-386",
 			"windows-amd64", "windows-386":
@@ -1011,7 +1011,7 @@ func (t *tester) supportedBuildmode(mode string) bool {
 		switch pair {
 		case "linux-386", "linux-amd64", "linux-arm", "linux-s390x", "linux-ppc64le":
 			return true
-		case "darwin-amd64":
+		case "darwin-amd64", "darwin-arm64":
 			return true
 		case "freebsd-amd64":
 			return true
@@ -1023,7 +1023,7 @@ func (t *tester) supportedBuildmode(mode string) bool {
 			"linux-386", "linux-amd64", "linux-arm", "linux-arm64", "linux-ppc64le", "linux-s390x",
 			"android-amd64", "android-arm", "android-arm64", "android-386":
 			return true
-		case "darwin-amd64":
+		case "darwin-amd64", "darwin-arm64":
 			return true
 		case "windows-amd64", "windows-386", "windows-arm":
 			return true

src/cmd/doc/doc_test.go

@@ -36,7 +36,7 @@ func TestMain(m *testing.M) {
 }
 
 func maybeSkip(t *testing.T) {
-	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && runtime.GOARCH == "arm64" {
+	if runtime.GOOS == "ios" {
 		t.Skip("iOS does not have a full file tree")
 	}
 }

src/cmd/fix/gotypes.go

@@ -21,11 +21,11 @@ var gotypesFix = fix{
 }
 
 func gotypes(f *ast.File) bool {
-	truth := fixGoTypes(f)
+	fixed := fixGoTypes(f)
 	if fixGoExact(f) {
-		truth = true
+		fixed = true
 	}
-	return truth
+	return fixed
 }
 
 func fixGoTypes(f *ast.File) bool {

src/cmd/fix/main.go

@@ -137,6 +137,21 @@ func processFile(filename string, useStdin bool) error {
 		return err
 	}
 
+	// Make sure file is in canonical format.
+	// This "fmt" pseudo-fix cannot be disabled.
+	newSrc, err := gofmtFile(file)
+	if err != nil {
+		return err
+	}
+	if !bytes.Equal(newSrc, src) {
+		newFile, err := parser.ParseFile(fset, filename, newSrc, parserMode)
+		if err != nil {
+			return err
+		}
+		file = newFile
+		fmt.Fprintf(&fixlog, " fmt")
+	}
+
 	// Apply all fixes to file.
 	newFile := file
 	fixed := false
@@ -180,7 +195,7 @@ func processFile(filename string, useStdin bool) error {
 	// output of the printer run on a standard AST generated by the parser,
 	// but the source we generated inside the loop above is the
 	// output of the printer run on a mangled AST generated by a fixer.
-	newSrc, err := gofmtFile(newFile)
+	newSrc, err = gofmtFile(newFile)
 	if err != nil {
 		return err
 	}

src/cmd/fix/typecheck.go

@@ -207,7 +207,7 @@ func typecheck(cfg *TypeConfig, f *ast.File) (typeof map[interface{}]string, ass
 			return nil
 		}()
 		if err != nil {
-			fmt.Printf("warning: no cgo types: %s\n", err)
+			fmt.Fprintf(os.Stderr, "go fix: warning: no cgo types: %s\n", err)
 		}
 	}
 

src/cmd/go.mod

@@ -3,7 +3,7 @@ module cmd
 go 1.16
 
 require (
-	github.com/google/pprof v0.0.0-20200229191704-1ebb73c60ed3
+	github.com/google/pprof v0.0.0-20200708004538-1a94d8640e99
 	github.com/ianlancetaylor/demangle v0.0.0-20200414190113-039b1ae3a340 // indirect
 	golang.org/x/arch v0.0.0-20200826200359-b19915210f00
 	golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a

src/cmd/go.sum

@@ -1,8 +1,8 @@
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
-github.com/google/pprof v0.0.0-20200229191704-1ebb73c60ed3 h1:SRgJV+IoxM5MKyFdlSUeNy6/ycRUF2yBAKdAQswoHUk=
+github.com/google/pprof v0.0.0-20200708004538-1a94d8640e99 h1:Ak8CrdlwwXwAZxzS66vgPt4U8yUZX7JwLvVR58FN5jM=
-github.com/google/pprof v0.0.0-20200229191704-1ebb73c60ed3/go.mod h1:ZgVRPoUq/hfqzAqh7sHMqb3I9Rq5C59dIz2SbBwJ4eM=
+github.com/google/pprof v0.0.0-20200708004538-1a94d8640e99/go.mod h1:ZgVRPoUq/hfqzAqh7sHMqb3I9Rq5C59dIz2SbBwJ4eM=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/ianlancetaylor/demangle v0.0.0-20200414190113-039b1ae3a340 h1:S1+yTUaFPXuDZnPDbO+TrDFIjPzQraYH8/CwSlu9Fac=
 github.com/ianlancetaylor/demangle v0.0.0-20200414190113-039b1ae3a340/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=

src/cmd/go/alldocs.go

@@ -1852,6 +1852,9 @@
 // 	GOARM
 // 		For GOARCH=arm, the ARM architecture for which to compile.
 // 		Valid values are 5, 6, 7.
+// 	GO386
+// 		For GOARCH=386, how to implement floating point instructions.
+// 		Valid values are sse2 (default), softfloat.
 // 	GOMIPS
 // 		For GOARCH=mips{,le}, whether to use floating point instructions.
 // 		Valid values are hardfloat (default), softfloat.

src/cmd/go/go_test.go

@@ -58,11 +58,10 @@ func init() {
 	switch runtime.GOOS {
 	case "android", "js":
 		canRun = false
-	case "darwin", "ios":
+	case "darwin":
-		switch runtime.GOARCH {
+		// nothing to do
-		case "arm64":
+	case "ios":
-			canRun = false
+		canRun = false
-		}
 	case "linux":
 		switch runtime.GOARCH {
 		case "arm":

src/cmd/go/internal/cfg/cfg.go

@@ -256,6 +256,7 @@ var (
 
 	// Used in envcmd.MkEnv and build ID computations.
 	GOARM    = envOr("GOARM", fmt.Sprint(objabi.GOARM))
+	GO386    = envOr("GO386", objabi.GO386)
 	GOMIPS   = envOr("GOMIPS", objabi.GOMIPS)
 	GOMIPS64 = envOr("GOMIPS64", objabi.GOMIPS64)
 	GOPPC64  = envOr("GOPPC64", fmt.Sprintf("%s%d", "power", objabi.GOPPC64))
@@ -279,6 +280,8 @@ func GetArchEnv() (key, val string) {
 	switch Goarch {
 	case "arm":
 		return "GOARM", GOARM
+	case "386":
+		return "GO386", GO386
 	case "mips", "mipsle":
 		return "GOMIPS", GOMIPS
 	case "mips64", "mips64le":

src/cmd/go/internal/envcmd/env.go

@@ -203,10 +203,19 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
 	}
 
 	// Do we need to call ExtraEnvVarsCostly, which is a bit expensive?
-	// Only if we're listing all environment variables ("go env")
+	needCostly := false
-	// or the variables being requested are in the extra list.
+	if *envU || *envW {
-	needCostly := true
+		// We're overwriting or removing default settings,
-	if len(args) > 0 {
+		// so it doesn't really matter what the existing settings are.
+		//
+		// Moreover, we haven't validated the new settings yet, so it is
+		// important that we NOT perform any actions based on them,
+		// such as initializing the builder to compute other variables.
+	} else if len(args) == 0 {
+		// We're listing all environment variables ("go env"),
+		// including the expensive ones.
+		needCostly = true
+	} else {
 		needCostly = false
 		for _, arg := range args {
 			switch argKey(arg) {
@@ -269,6 +278,13 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
 			}
 		}
 
+		gotmp, okGOTMP := add["GOTMPDIR"]
+		if okGOTMP {
+			if !filepath.IsAbs(gotmp) && gotmp != "" {
+				base.Fatalf("go env -w: GOTMPDIR must be an absolute path")
+			}
+		}
+
 		updateEnvFile(add, nil)
 		return
 	}

src/cmd/go/internal/help/helpdoc.go

@@ -581,6 +581,9 @@ Architecture-specific environment variables:
 	GOARM
 		For GOARCH=arm, the ARM architecture for which to compile.
 		Valid values are 5, 6, 7.
+	GO386
+		For GOARCH=386, how to implement floating point instructions.
+		Valid values are sse2 (default), softfloat.
 	GOMIPS
 		For GOARCH=mips{,le}, whether to use floating point instructions.
 		Valid values are hardfloat (default), softfloat.

src/cmd/go/internal/load/pkg.go

@@ -75,19 +75,20 @@ type PackagePublic struct {
 	// Source files
 	// If you add to this list you MUST add to p.AllFiles (below) too.
 	// Otherwise file name security lists will not apply to any new additions.
-	GoFiles         []string `json:",omitempty"` // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
+	GoFiles           []string `json:",omitempty"` // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
-	CgoFiles        []string `json:",omitempty"` // .go source files that import "C"
+	CgoFiles          []string `json:",omitempty"` // .go source files that import "C"
-	CompiledGoFiles []string `json:",omitempty"` // .go output from running cgo on CgoFiles
+	CompiledGoFiles   []string `json:",omitempty"` // .go output from running cgo on CgoFiles
-	IgnoredGoFiles  []string `json:",omitempty"` // .go source files ignored due to build constraints
+	IgnoredGoFiles    []string `json:",omitempty"` // .go source files ignored due to build constraints
-	CFiles          []string `json:",omitempty"` // .c source files
+	IgnoredOtherFiles []string `json:",omitempty"` // non-.go source files ignored due to build constraints
-	CXXFiles        []string `json:",omitempty"` // .cc, .cpp and .cxx source files
+	CFiles            []string `json:",omitempty"` // .c source files
-	MFiles          []string `json:",omitempty"` // .m source files
+	CXXFiles          []string `json:",omitempty"` // .cc, .cpp and .cxx source files
-	HFiles          []string `json:",omitempty"` // .h, .hh, .hpp and .hxx source files
+	MFiles            []string `json:",omitempty"` // .m source files
-	FFiles          []string `json:",omitempty"` // .f, .F, .for and .f90 Fortran source files
+	HFiles            []string `json:",omitempty"` // .h, .hh, .hpp and .hxx source files
-	SFiles          []string `json:",omitempty"` // .s source files
+	FFiles            []string `json:",omitempty"` // .f, .F, .for and .f90 Fortran source files
-	SwigFiles       []string `json:",omitempty"` // .swig files
+	SFiles            []string `json:",omitempty"` // .s source files
-	SwigCXXFiles    []string `json:",omitempty"` // .swigcxx files
+	SwigFiles         []string `json:",omitempty"` // .swig files
-	SysoFiles       []string `json:",omitempty"` // .syso system object files added to package
+	SwigCXXFiles      []string `json:",omitempty"` // .swigcxx files
+	SysoFiles         []string `json:",omitempty"` // .syso system object files added to package
 
 	// Cgo directives
 	CgoCFLAGS    []string `json:",omitempty"` // cgo: flags for C compiler
@@ -127,6 +128,7 @@ func (p *Package) AllFiles() []string {
 		p.CgoFiles,
 		// no p.CompiledGoFiles, because they are from GoFiles or generated by us
 		p.IgnoredGoFiles,
+		p.IgnoredOtherFiles,
 		p.CFiles,
 		p.CXXFiles,
 		p.MFiles,
@@ -185,7 +187,7 @@ type NoGoError struct {
 }
 
 func (e *NoGoError) Error() string {
-	if len(e.Package.constraintIgnoredGoFiles()) > 0 {
+	if len(e.Package.IgnoredGoFiles) > 0 {
 		// Go files exist, but they were ignored due to build constraints.
 		return "build constraints exclude all Go files in " + e.Package.Dir
 	}
@@ -330,6 +332,7 @@ func (p *Package) copyBuild(pp *build.Package) {
 	p.GoFiles = pp.GoFiles
 	p.CgoFiles = pp.CgoFiles
 	p.IgnoredGoFiles = pp.IgnoredGoFiles
+	p.IgnoredOtherFiles = pp.IgnoredOtherFiles
 	p.CFiles = pp.CFiles
 	p.CXXFiles = pp.CXXFiles
 	p.MFiles = pp.MFiles
@@ -2009,22 +2012,7 @@ func (p *Package) InternalXGoFiles() []string {
 // using absolute paths. "Possibly relevant" means that files are not excluded
 // due to build tags, but files with names beginning with . or _ are still excluded.
 func (p *Package) InternalAllGoFiles() []string {
-	return p.mkAbs(str.StringList(p.constraintIgnoredGoFiles(), p.GoFiles, p.CgoFiles, p.TestGoFiles, p.XTestGoFiles))
+	return p.mkAbs(str.StringList(p.IgnoredGoFiles, p.GoFiles, p.CgoFiles, p.TestGoFiles, p.XTestGoFiles))
-}
-
-// constraintIgnoredGoFiles returns the list of Go files ignored for reasons
-// other than having a name beginning with '.' or '_'.
-func (p *Package) constraintIgnoredGoFiles() []string {
-	if len(p.IgnoredGoFiles) == 0 {
-		return nil
-	}
-	files := make([]string, 0, len(p.IgnoredGoFiles))
-	for _, f := range p.IgnoredGoFiles {
-		if f != "" && f[0] != '.' && f[0] != '_' {
-			files = append(files, f)
-		}
-	}
-	return files
 }
 
 // usesSwig reports whether the package needs to run SWIG.

src/cmd/go/internal/modfetch/codehost/codehost.go

@@ -79,9 +79,8 @@ type Repo interface {
 	ReadZip(rev, subdir string, maxSize int64) (zip io.ReadCloser, err error)
 
 	// RecentTag returns the most recent tag on rev or one of its predecessors
-	// with the given prefix and major version.
+	// with the given prefix. allowed may be used to filter out unwanted versions.
-	// An empty major string matches any major version.
+	RecentTag(rev, prefix string, allowed func(string) bool) (tag string, err error)
-	RecentTag(rev, prefix, major string) (tag string, err error)
 
 	// DescendsFrom reports whether rev or any of its ancestors has the given tag.
 	//

src/cmd/go/internal/modfetch/codehost/git.go

@@ -644,7 +644,7 @@ func (r *gitRepo) readFileRevs(tags []string, file string, fileMap map[string]*F
 	return missing, nil
 }
 
-func (r *gitRepo) RecentTag(rev, prefix, major string) (tag string, err error) {
+func (r *gitRepo) RecentTag(rev, prefix string, allowed func(string) bool) (tag string, err error) {
 	info, err := r.Stat(rev)
 	if err != nil {
 		return "", err
@@ -680,7 +680,10 @@ func (r *gitRepo) RecentTag(rev, prefix, major string) (tag string, err error) {
 			// NOTE: Do not replace the call to semver.Compare with semver.Max.
 			// We want to return the actual tag, not a canonicalized version of it,
 			// and semver.Max currently canonicalizes (see golang.org/issue/32700).
-			if c := semver.Canonical(semtag); c != "" && strings.HasPrefix(semtag, c) && (major == "" || semver.Major(c) == major) && semver.Compare(semtag, highest) > 0 {
+			if c := semver.Canonical(semtag); c == "" || !strings.HasPrefix(semtag, c) || !allowed(semtag) {
+				continue
+			}
+			if semver.Compare(semtag, highest) > 0 {
 				highest = semtag
 			}
 		}

src/cmd/go/internal/modfetch/codehost/vcs.go

@@ -395,7 +395,7 @@ func (r *vcsRepo) ReadFileRevs(revs []string, file string, maxSize int64) (map[s
 	return nil, vcsErrorf("ReadFileRevs not implemented")
 }
 
-func (r *vcsRepo) RecentTag(rev, prefix, major string) (tag string, err error) {
+func (r *vcsRepo) RecentTag(rev, prefix string, allowed func(string) bool) (tag string, err error) {
 	// We don't technically need to lock here since we're returning an error
 	// uncondititonally, but doing so anyway will help to avoid baking in
 	// lock-inversion bugs.

src/cmd/go/internal/modfetch/coderepo.go

@@ -419,9 +419,14 @@ func (r *codeRepo) convert(info *codehost.RevInfo, statVers string) (*RevInfo, e
 		tagPrefix = r.codeDir + "/"
 	}
 
+	isRetracted, err := r.retractedVersions()
+	if err != nil {
+		isRetracted = func(string) bool { return false }
+	}
+
 	// tagToVersion returns the version obtained by trimming tagPrefix from tag.
-	// If the tag is invalid or a pseudo-version, tagToVersion returns an empty
+	// If the tag is invalid, retracted, or a pseudo-version, tagToVersion returns
-	// version.
+	// an empty version.
 	tagToVersion := func(tag string) (v string, tagIsCanonical bool) {
 		if !strings.HasPrefix(tag, tagPrefix) {
 			return "", false
@@ -436,6 +441,9 @@ func (r *codeRepo) convert(info *codehost.RevInfo, statVers string) (*RevInfo, e
 		if v == "" || !strings.HasPrefix(trimmed, v) {
 			return "", false // Invalid or incomplete version (just vX or vX.Y).
 		}
+		if isRetracted(v) {
+			return "", false
+		}
 		if v == trimmed {
 			tagIsCanonical = true
 		}
@@ -500,15 +508,24 @@ func (r *codeRepo) convert(info *codehost.RevInfo, statVers string) (*RevInfo, e
 		return checkGoMod()
 	}
 
+	// Find the highest tagged version in the revision's history, subject to
+	// major version and +incompatible constraints. Use that version as the
+	// pseudo-version base so that the pseudo-version sorts higher. Ignore
+	// retracted versions.
+	allowedMajor := func(major string) func(v string) bool {
+		return func(v string) bool {
+			return (major == "" || semver.Major(v) == major) && !isRetracted(v)
+		}
+	}
 	if pseudoBase == "" {
 		var tag string
 		if r.pseudoMajor != "" || canUseIncompatible() {
-			tag, _ = r.code.RecentTag(info.Name, tagPrefix, r.pseudoMajor)
+			tag, _ = r.code.RecentTag(info.Name, tagPrefix, allowedMajor(r.pseudoMajor))
 		} else {
 			// Allow either v1 or v0, but not incompatible higher versions.
-			tag, _ = r.code.RecentTag(info.Name, tagPrefix, "v1")
+			tag, _ = r.code.RecentTag(info.Name, tagPrefix, allowedMajor("v1"))
 			if tag == "" {
-				tag, _ = r.code.RecentTag(info.Name, tagPrefix, "v0")
+				tag, _ = r.code.RecentTag(info.Name, tagPrefix, allowedMajor("v0"))
 			}
 		}
 		pseudoBase, _ = tagToVersion(tag) // empty if the tag is invalid
@@ -869,6 +886,57 @@ func (r *codeRepo) modPrefix(rev string) string {
 	return r.modPath + "@" + rev
 }
 
+func (r *codeRepo) retractedVersions() (func(string) bool, error) {
+	versions, err := r.Versions("")
+	if err != nil {
+		return nil, err
+	}
+
+	for i, v := range versions {
+		if strings.HasSuffix(v, "+incompatible") {
+			versions = versions[:i]
+			break
+		}
+	}
+	if len(versions) == 0 {
+		return func(string) bool { return false }, nil
+	}
+
+	var highest string
+	for i := len(versions) - 1; i >= 0; i-- {
+		v := versions[i]
+		if semver.Prerelease(v) == "" {
+			highest = v
+			break
+		}
+	}
+	if highest == "" {
+		highest = versions[len(versions)-1]
+	}
+
+	data, err := r.GoMod(highest)
+	if err != nil {
+		return nil, err
+	}
+	f, err := modfile.ParseLax("go.mod", data, nil)
+	if err != nil {
+		return nil, err
+	}
+	retractions := make([]modfile.VersionInterval, len(f.Retract))
+	for _, r := range f.Retract {
+		retractions = append(retractions, r.VersionInterval)
+	}
+
+	return func(v string) bool {
+		for _, r := range retractions {
+			if semver.Compare(r.Low, v) <= 0 && semver.Compare(v, r.High) <= 0 {
+				return true
+			}
+		}
+		return false
+	}, nil
+}
+
 func (r *codeRepo) Zip(dst io.Writer, version string) error {
 	if version != module.CanonicalVersion(version) {
 		return fmt.Errorf("version %s is not canonical", version)

src/cmd/go/internal/work/build_test.go

@@ -221,10 +221,8 @@ func pkgImportPath(pkgpath string) *load.Package {
 // See https://golang.org/issue/18878.
 func TestRespectSetgidDir(t *testing.T) {
 	switch runtime.GOOS {
-	case "darwin", "ios":
+	case "ios":
-		if runtime.GOARCH == "arm64" {
+		t.Skip("can't set SetGID bit with chmod on iOS")
-			t.Skip("can't set SetGID bit with chmod on iOS")
-		}
 	case "windows", "plan9":
 		t.Skip("chown/chmod setgid are not supported on Windows or Plan 9")
 	}

src/cmd/go/internal/work/exec.go

@@ -922,12 +922,13 @@ func (b *Builder) loadCachedSrcFiles(a *Action) error {
 
 // vetConfig is the configuration passed to vet describing a single package.
 type vetConfig struct {
-	ID         string   // package ID (example: "fmt [fmt.test]")
+	ID           string   // package ID (example: "fmt [fmt.test]")
-	Compiler   string   // compiler name (gc, gccgo)
+	Compiler     string   // compiler name (gc, gccgo)
-	Dir        string   // directory containing package
+	Dir          string   // directory containing package
-	ImportPath string   // canonical import path ("package path")
+	ImportPath   string   // canonical import path ("package path")
-	GoFiles    []string // absolute paths to package source files
+	GoFiles      []string // absolute paths to package source files
-	NonGoFiles []string // absolute paths to package non-Go files
+	NonGoFiles   []string // absolute paths to package non-Go files
+	IgnoredFiles []string // absolute paths to ignored source files
 
 	ImportMap   map[string]string // map import path in source code to package path
 	PackageFile map[string]string // map package path to .a file with export data
@@ -951,20 +952,23 @@ func buildVetConfig(a *Action, srcfiles []string) {
 		}
 	}
 
+	ignored := str.StringList(a.Package.IgnoredGoFiles, a.Package.IgnoredOtherFiles)
+
 	// Pass list of absolute paths to vet,
 	// so that vet's error messages will use absolute paths,
 	// so that we can reformat them relative to the directory
 	// in which the go command is invoked.
 	vcfg := &vetConfig{
-		ID:          a.Package.ImportPath,
+		ID:           a.Package.ImportPath,
-		Compiler:    cfg.BuildToolchainName,
+		Compiler:     cfg.BuildToolchainName,
-		Dir:         a.Package.Dir,
+		Dir:          a.Package.Dir,
-		GoFiles:     mkAbsFiles(a.Package.Dir, gofiles),
+		GoFiles:      mkAbsFiles(a.Package.Dir, gofiles),
-		NonGoFiles:  mkAbsFiles(a.Package.Dir, nongofiles),
+		NonGoFiles:   mkAbsFiles(a.Package.Dir, nongofiles),
-		ImportPath:  a.Package.ImportPath,
+		IgnoredFiles: mkAbsFiles(a.Package.Dir, ignored),
-		ImportMap:   make(map[string]string),
+		ImportPath:   a.Package.ImportPath,
-		PackageFile: make(map[string]string),
+		ImportMap:    make(map[string]string),
-		Standard:    make(map[string]bool),
+		PackageFile:  make(map[string]string),
+		Standard:     make(map[string]bool),
 	}
 	a.vetCfg = vcfg
 	for i, raw := range a.Package.Internal.RawImports {
@@ -1052,17 +1056,28 @@ func (b *Builder) vet(ctx context.Context, a *Action) error {
 	// This is OK as long as the packages that are farther down the
 	// dependency tree turn on *more* analysis, as here.
 	// (The unsafeptr check does not write any facts for use by
-	// later vet runs.)
+	// later vet runs, nor does unreachable.)
 	if a.Package.Goroot && !VetExplicit && VetTool == "" {
+		// Turn off -unsafeptr checks.
+		// There's too much unsafe.Pointer code
+		// that vet doesn't like in low-level packages
+		// like runtime, sync, and reflect.
 		// Note that $GOROOT/src/buildall.bash
 		// does the same for the misc-compile trybots
 		// and should be updated if these flags are
 		// changed here.
-		//
-		// There's too much unsafe.Pointer code
-		// that vet doesn't like in low-level packages
-		// like runtime, sync, and reflect.
 		vetFlags = []string{"-unsafeptr=false"}
+
+		// Also turn off -unreachable checks during go test.
+		// During testing it is very common to make changes
+		// like hard-coded forced returns or panics that make
+		// code unreachable. It's unreasonable to insist on files
+		// not having any unreachable code during "go test".
+		// (buildall.bash still runs with -unreachable enabled
+		// for the overall whole-tree scan.)
+		if cfg.CmdName == "test" {
+			vetFlags = append(vetFlags, "-unreachable=false")
+		}
 	}
 
 	// Note: We could decide that vet should compute export data for

src/cmd/go/testdata/script/env_write.txt

@@ -24,6 +24,12 @@ stdout GOARCH=
 stdout GOOS=
 stdout GOROOT=
 
+# checking errors
+! go env -w
+stderr 'go env -w: no KEY=VALUE arguments given'
+! go env -u
+stderr 'go env -u: no arguments given'
+
 # go env -w changes default setting
 env root=
 [windows] env root=c:
@@ -97,6 +103,26 @@ stderr 'GOPATH entry cannot start with shell metacharacter'
 ! go env -w GOPATH=./go
 stderr 'GOPATH entry is relative; must be absolute path'
 
+# go env -w rejects invalid GOTMPDIR values
+! go env -w GOTMPDIR=x
+stderr 'go env -w: GOTMPDIR must be an absolute path'
+
+# go env -w should accept absolute GOTMPDIR value
+# and should not create it
+[windows] go env -w GOTMPDIR=$WORK\x\y\z
+[!windows] go env -w GOTMPDIR=$WORK/x/y/z
+! exists $WORK/x/y/z
+# we should be able to clear an env
+go env -u GOTMPDIR
+go env GOTMPDIR
+stdout ^$
+
+[windows] go env -w GOTMPDIR=$WORK\x\y\z
+[!windows] go env -w GOTMPDIR=$WORK/x/y/z
+go env -w GOTMPDIR=
+go env GOTMPDIR
+stdout ^$
+
 # go env -w/-u checks validity of GOOS/ARCH combinations
 env GOOS=
 env GOARCH=

src/cmd/go/testdata/script/mod_retract_pseudo_base.txt

@@ -0,0 +1,62 @@
+# When converting a commit to a pseudo-version, don't use a retracted version
+# as the base.
+# Verifies golang.org/issue/41700.
+
+[!net] skip
+[!exec:git] skip
+env GOPROXY=direct
+env GOSUMDB=off
+go mod init m
+
+# Control: check that v1.0.0 is the only version and is retracted.
+go list -m -versions vcs-test.golang.org/git/retract-pseudo.git
+stdout '^vcs-test.golang.org/git/retract-pseudo.git$'
+go list -m -versions -retracted vcs-test.golang.org/git/retract-pseudo.git
+stdout '^vcs-test.golang.org/git/retract-pseudo.git v1.0.0$'
+
+# 713affd19d7b is a commit after v1.0.0. Don't use v1.0.0 as the base.
+go list -m vcs-test.golang.org/git/retract-pseudo.git@713affd19d7b
+stdout '^vcs-test.golang.org/git/retract-pseudo.git v0.0.0-20201009173747-713affd19d7b$'
+
+# 64c061ed4371 is the commit v1.0.0 refers to. Don't convert to v1.0.0.
+go list -m vcs-test.golang.org/git/retract-pseudo.git@64c061ed4371
+stdout '^vcs-test.golang.org/git/retract-pseudo.git v0.0.0-20201009173747-64c061ed4371'
+
+# A retracted version is a valid base. Retraction should not validate existing
+# pseudo-versions, nor should it turn invalid pseudo-versions valid.
+go get -d vcs-test.golang.org/git/retract-pseudo.git@v1.0.1-0.20201009173747-713affd19d7b
+go list -m vcs-test.golang.org/git/retract-pseudo.git
+stdout '^vcs-test.golang.org/git/retract-pseudo.git v1.0.1-0.20201009173747-713affd19d7b$'
+
+! go get -d vcs-test.golang.org/git/retract-pseudo.git@v1.0.1-0.20201009173747-64c061ed4371
+stderr '^go get vcs-test.golang.org/git/retract-pseudo.git@v1.0.1-0.20201009173747-64c061ed4371: vcs-test.golang.org/git/retract-pseudo.git@v1.0.1-0.20201009173747-64c061ed4371: invalid pseudo-version: tag \(v1.0.0\) found on revision 64c061ed4371 is already canonical, so should not be replaced with a pseudo-version derived from that tag$'
+
+-- retract-pseudo.sh --
+#!/bin/bash
+
+# This is not part of the test.
+# Run this to generate and update the repository on vcs-test.golang.org.
+
+set -euo pipefail
+
+rm -rf retract-pseudo
+mkdir retract-pseudo
+cd retract-pseudo
+git init
+
+# Create the module.
+# Retract v1.0.0 and tag v1.0.0 at the same commit.
+# The module has no unretracted release versions.
+go mod init vcs-test.golang.org/git/retract-pseudo.git
+go mod edit -retract v1.0.0
+echo 'package p' >p.go
+git add -A
+git commit -m 'create module retract-pseudo'
+git tag v1.0.0
+
+# Commit a trivial change so the default branch does not point to v1.0.0.
+git mv p.go q.go
+git commit -m 'trivial change'
+
+zip -r ../retract-pseudo.zip .
+gsutil cp ../retract-pseudo.zip gs://vcs-test/git/retract-pseudo.zip

src/cmd/go/testdata/script/vet_flags.txt

@@ -2,21 +2,25 @@ env GO111MODULE=on
 
 # Issue 35837: "go vet -<analyzer> <std package>" should use the requested
 # analyzers, not the default analyzers for 'go test'.
-go vet -n -unreachable=false encoding/binary
+go vet -n -buildtags=false runtime
-stderr '-unreachable=false'
+stderr '-buildtags=false'
 ! stderr '-unsafeptr=false'
 
 # Issue 37030: "go vet <std package>" without other flags should disable the
 # unsafeptr check by default.
-go vet -n encoding/binary
+go vet -n runtime
 stderr '-unsafeptr=false'
 ! stderr '-unreachable=false'
 
 # However, it should be enabled if requested explicitly.
-go vet -n -unsafeptr encoding/binary
+go vet -n -unsafeptr runtime
 stderr '-unsafeptr'
 ! stderr '-unsafeptr=false'
 
+# -unreachable is disabled during test but on during plain vet.
+go test -n runtime
+stderr '-unreachable=false'
+
 # A flag terminator should be allowed before the package list.
 go vet -n -- .
 
@@ -60,10 +64,10 @@ stderr '[/\\]vet'$GOEXE'["]? .* -errorsas .* ["]?\$WORK[/\\][^ ]*[/\\]vet\.cfg'
 
 # "go test" on a standard package should by default disable an explicit list.
 go test -x -run=none encoding/binary
-stderr '[/\\]vet'$GOEXE'["]? -unsafeptr=false ["]?\$WORK[/\\][^ ]*[/\\]vet\.cfg'
+stderr '[/\\]vet'$GOEXE'["]? -unsafeptr=false -unreachable=false ["]?\$WORK[/\\][^ ]*[/\\]vet\.cfg'
 
 go test -x -vet= -run=none encoding/binary
-stderr '[/\\]vet'$GOEXE'["]? -unsafeptr=false ["]?\$WORK[/\\][^ ]*[/\\]vet\.cfg'
+stderr '[/\\]vet'$GOEXE'["]? -unsafeptr=false -unreachable=false ["]?\$WORK[/\\][^ ]*[/\\]vet\.cfg'
 
 # Both should allow users to override via the -vet flag.
 go test -x -vet=unreachable -run=none .

src/cmd/internal/obj/arm64/a.out.go

@@ -958,9 +958,11 @@ const (
 	AVADDP
 	AVAND
 	AVBIF
+	AVBCAX
 	AVCMEQ
 	AVCNT
 	AVEOR
+	AVEOR3
 	AVMOV
 	AVLD1
 	AVLD2
@@ -989,6 +991,7 @@ const (
 	AVPMULL2
 	AVEXT
 	AVRBIT
+	AVRAX1
 	AVUSHR
 	AVUSHLL
 	AVUSHLL2
@@ -1001,6 +1004,7 @@ const (
 	AVBSL
 	AVBIT
 	AVTBL
+	AVXAR
 	AVZIP1
 	AVZIP2
 	AVCMTST

src/cmd/internal/obj/arm64/anames.go

@@ -464,9 +464,11 @@ var Anames = []string{
 	"VADDP",
 	"VAND",
 	"VBIF",
+	"VBCAX",
 	"VCMEQ",
 	"VCNT",
 	"VEOR",
+	"VEOR3",
 	"VMOV",
 	"VLD1",
 	"VLD2",
@@ -495,6 +497,7 @@ var Anames = []string{
 	"VPMULL2",
 	"VEXT",
 	"VRBIT",
+	"VRAX1",
 	"VUSHR",
 	"VUSHLL",
 	"VUSHLL2",
@@ -507,6 +510,7 @@ var Anames = []string{
 	"VBSL",
 	"VBIT",
 	"VTBL",
+	"VXAR",
 	"VZIP1",
 	"VZIP2",
 	"VCMTST",

src/cmd/internal/obj/arm64/asm7.go

@@ -843,6 +843,8 @@ var optab = []Optab{
 	{ASHA256H, C_ARNG, C_VREG, C_NONE, C_VREG, 1, 4, 0, 0, 0},
 	{AVREV32, C_ARNG, C_NONE, C_NONE, C_ARNG, 83, 4, 0, 0, 0},
 	{AVPMULL, C_ARNG, C_ARNG, C_NONE, C_ARNG, 93, 4, 0, 0, 0},
+	{AVEOR3, C_ARNG, C_ARNG, C_ARNG, C_ARNG, 103, 4, 0, 0, 0},
+	{AVXAR, C_VCON, C_ARNG, C_ARNG, C_ARNG, 104, 4, 0, 0, 0},
 
 	{obj.AUNDEF, C_NONE, C_NONE, C_NONE, C_NONE, 90, 4, 0, 0, 0},
 	{obj.APCDATA, C_VCON, C_NONE, C_NONE, C_VCON, 0, 0, 0, 0, 0},
@@ -2769,6 +2771,7 @@ func buildop(ctxt *obj.Link) {
 
 		case AVADD:
 			oprangeset(AVSUB, t)
+			oprangeset(AVRAX1, t)
 
 		case AAESD:
 			oprangeset(AAESE, t)
@@ -2827,6 +2830,9 @@ func buildop(ctxt *obj.Link) {
 			oprangeset(AVLD4, t)
 			oprangeset(AVLD4R, t)
 
+		case AVEOR3:
+			oprangeset(AVBCAX, t)
+
 		case ASHA1H,
 			AVCNT,
 			AVMOV,
@@ -2839,7 +2845,8 @@ func buildop(ctxt *obj.Link) {
 			AVDUP,
 			AVMOVI,
 			APRFM,
-			AVEXT:
+			AVEXT,
+			AVXAR:
 			break
 
 		case obj.ANOP,
@@ -3120,12 +3127,13 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 
 	case 6: /* b ,O(R); bl ,O(R) */
 		o1 = c.opbrr(p, p.As)
-
 		o1 |= uint32(p.To.Reg&31) << 5
-		rel := obj.Addrel(c.cursym)
+		if p.As == obj.ACALL {
-		rel.Off = int32(c.pc)
+			rel := obj.Addrel(c.cursym)
-		rel.Siz = 0
+			rel.Off = int32(c.pc)
-		rel.Type = objabi.R_CALLIND
+			rel.Siz = 0
+			rel.Type = objabi.R_CALLIND
+		}
 
 	case 7: /* beq s */
 		o1 = c.opbra(p, p.As)
@@ -4204,7 +4212,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		rel.Add = 0
 		rel.Type = objabi.R_ARM64_GOTPCREL
 
-	case 72: /* vaddp/vand/vcmeq/vorr/vadd/veor/vfmla/vfmls/vbit/vbsl/vcmtst/vsub/vbif/vuzip1/vuzip2 Vm.<T>, Vn.<T>, Vd.<T> */
+	case 72: /* vaddp/vand/vcmeq/vorr/vadd/veor/vfmla/vfmls/vbit/vbsl/vcmtst/vsub/vbif/vuzip1/vuzip2/vrax1 Vm.<T>, Vn.<T>, Vd.<T> */
 		af := int((p.From.Reg >> 5) & 15)
 		af3 := int((p.Reg >> 5) & 15)
 		at := int((p.To.Reg >> 5) & 15)
@@ -4268,6 +4276,12 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			} else {
 				size = 0
 			}
+		case AVRAX1:
+			if af != ARNG_2D {
+				c.ctxt.Diag("invalid arrangement: %v", p)
+			}
+			size = 0
+			Q = 0
 		}
 
 		o1 |= (uint32(Q&1) << 30) | (uint32(size&3) << 22) | (uint32(rf&31) << 16) | (uint32(r&31) << 5) | uint32(rt&31)
@@ -5185,6 +5199,51 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			c.ctxt.Diag("shift amount out of range: %v\n", p)
 		}
 		o1 |= uint32(immh)<<19 | uint32(shift)<<16 | uint32(rf&31)<<5 | uint32(p.To.Reg&31)
+	case 103: /* VEOR3/VBCAX Va.B16, Vm.B16, Vn.B16, Vd.B16 */
+		ta := (p.From.Reg >> 5) & 15
+		tm := (p.Reg >> 5) & 15
+		td := (p.To.Reg >> 5) & 15
+		tn := ((p.GetFrom3().Reg) >> 5) & 15
+
+		if ta != tm || ta != tn || ta != td || ta != ARNG_16B {
+			c.ctxt.Diag("invalid arrangement: %v", p)
+			break
+		}
+
+		o1 = c.oprrr(p, p.As)
+		ra := int(p.From.Reg)
+		rm := int(p.Reg)
+		rn := int(p.GetFrom3().Reg)
+		rd := int(p.To.Reg)
+		o1 |= uint32(rm&31)<<16 | uint32(ra&31)<<10 | uint32(rn&31)<<5 | uint32(rd)&31
+
+	case 104: /* vxar $imm4, Vm.<T>, Vn.<T>, Vd.<T> */
+		af := ((p.GetFrom3().Reg) >> 5) & 15
+		at := (p.To.Reg >> 5) & 15
+		a := (p.Reg >> 5) & 15
+		index := int(p.From.Offset)
+
+		if af != a || af != at {
+			c.ctxt.Diag("invalid arrangement: %v", p)
+			break
+		}
+
+		if af != ARNG_2D {
+			c.ctxt.Diag("invalid arrangement, should be D2: %v", p)
+			break
+		}
+
+		if index < 0 || index > 63 {
+			c.ctxt.Diag("illegal offset: %v", p)
+		}
+
+		o1 = c.opirr(p, p.As)
+		rf := (p.GetFrom3().Reg) & 31
+		rt := (p.To.Reg) & 31
+		r := (p.Reg) & 31
+
+		o1 |= (uint32(r&31) << 16) | (uint32(index&63) << 10) | (uint32(rf&31) << 5) | uint32(rt&31)
+
 	}
 	out[0] = o1
 	out[1] = o2
@@ -5760,6 +5819,9 @@ func (c *ctxt7) oprrr(p *obj.Prog, a obj.As) uint32 {
 	case AVAND:
 		return 7<<25 | 1<<21 | 7<<10
 
+	case AVBCAX:
+		return 0xCE<<24 | 1<<21
+
 	case AVCMEQ:
 		return 1<<29 | 0x71<<21 | 0x23<<10
 
@@ -5775,12 +5837,18 @@ func (c *ctxt7) oprrr(p *obj.Prog, a obj.As) uint32 {
 	case AVEOR:
 		return 1<<29 | 0x71<<21 | 7<<10
 
+	case AVEOR3:
+		return 0xCE << 24
+
 	case AVORR:
 		return 7<<25 | 5<<21 | 7<<10
 
 	case AVREV16:
 		return 3<<26 | 2<<24 | 1<<21 | 3<<11
 
+	case AVRAX1:
+		return 0xCE<<24 | 3<<21 | 1<<15 | 3<<10
+
 	case AVREV32:
 		return 11<<26 | 2<<24 | 1<<21 | 1<<11
 
@@ -6038,6 +6106,8 @@ func (c *ctxt7) opirr(p *obj.Prog, a obj.As) uint32 {
 
 	case AVUSHLL2, AVUXTL2:
 		return 3<<29 | 15<<24 | 0x29<<10
+	case AVXAR:
+		return 0xCE<<24 | 1<<23
 	}
 
 	c.ctxt.Diag("%v: bad irr %v", p, a)

src/cmd/internal/obj/arm64/obj7.go

@@ -589,7 +589,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 				q1.To.Reg = REGSP
 				q1.Spadj = c.autosize
 
-				if c.ctxt.Headtype == objabi.Hdarwin {
+				if objabi.GOOS == "ios" {
 					// iOS does not support SA_ONSTACK. We will run the signal handler
 					// on the G stack. If we write below SP, it may be clobbered by
 					// the signal handler. So we save LR after decrementing SP.

src/cmd/internal/objabi/util.go

@@ -24,6 +24,7 @@ var (
 	GOROOT   = envOr("GOROOT", defaultGOROOT)
 	GOARCH   = envOr("GOARCH", defaultGOARCH)
 	GOOS     = envOr("GOOS", defaultGOOS)
+	GO386    = envOr("GO386", defaultGO386)
 	GOAMD64  = goamd64()
 	GOARM    = goarm()
 	GOMIPS   = gomips()
@@ -135,14 +136,6 @@ func init() {
 	if GOARCH != "amd64" {
 		Regabi_enabled = 0
 	}
-
-	if v := os.Getenv("GO386"); v != "" && v != "sse2" {
-		msg := fmt.Sprintf("unsupported setting GO386=%s", v)
-		if v == "387" {
-			msg += ". 387 support was dropped in Go 1.16. Consider using gccgo instead."
-		}
-		log.Fatal(msg)
-	}
 }
 
 // Note: must agree with runtime.framepointer_enabled.

src/cmd/internal/sys/supported.go

@@ -32,6 +32,7 @@ func MSanSupported(goos, goarch string) bool {
 }
 
 // MustLinkExternal reports whether goos/goarch requires external linking.
+// (This is the opposite of internal/testenv.CanInternalLink. Keep them in sync.)
 func MustLinkExternal(goos, goarch string) bool {
 	switch goos {
 	case "android":
@@ -69,7 +70,7 @@ func BuildModeSupported(compiler, buildmode, goos, goarch string) bool {
 		case "linux/amd64", "linux/arm", "linux/arm64", "linux/386", "linux/ppc64le", "linux/s390x",
 			"android/amd64", "android/arm", "android/arm64", "android/386",
 			"freebsd/amd64",
-			"darwin/amd64",
+			"darwin/amd64", "darwin/arm64",
 			"windows/amd64", "windows/386":
 			return true
 		}
@@ -86,7 +87,7 @@ func BuildModeSupported(compiler, buildmode, goos, goarch string) bool {
 		case "linux/386", "linux/amd64", "linux/arm", "linux/arm64", "linux/ppc64le", "linux/s390x",
 			"android/amd64", "android/arm", "android/arm64", "android/386",
 			"freebsd/amd64",
-			"darwin/amd64",
+			"darwin/amd64", "darwin/arm64",
 			"aix/ppc64",
 			"windows/386", "windows/amd64", "windows/arm":
 			return true
@@ -104,7 +105,7 @@ func BuildModeSupported(compiler, buildmode, goos, goarch string) bool {
 		switch platform {
 		case "linux/amd64", "linux/arm", "linux/arm64", "linux/386", "linux/s390x", "linux/ppc64le",
 			"android/amd64", "android/arm", "android/arm64", "android/386",
-			"darwin/amd64",
+			"darwin/amd64", "darwin/arm64",
 			"freebsd/amd64":
 			return true
 		}

src/cmd/internal/sys/supported_test.go

@@ -0,0 +1,18 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package sys
+
+import (
+	"internal/testenv"
+	"runtime"
+	"testing"
+)
+
+func TestMustLinkExternalMatchesTestenv(t *testing.T) {
+	// MustLinkExternal and testenv.CanInternalLink are the exact opposite.
+	if b := MustLinkExternal(runtime.GOOS, runtime.GOARCH); b != !testenv.CanInternalLink() {
+		t.Fatalf("MustLinkExternal() == %v, testenv.CanInternalLink() == %v, don't match", b, testenv.CanInternalLink())
+	}
+}

src/cmd/link/internal/arm64/asm.go

@@ -371,7 +371,7 @@ func machoreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sy
 	rt := r.Type
 	siz := r.Size
 
-	if ldr.SymType(rs) == sym.SHOSTOBJ || rt == objabi.R_CALLARM64 || rt == objabi.R_ADDRARM64 {
+	if ldr.SymType(rs) == sym.SHOSTOBJ || rt == objabi.R_CALLARM64 || rt == objabi.R_ADDRARM64 || rt == objabi.R_ARM64_GOTPCREL {
 		if ldr.SymDynid(rs) < 0 {
 			ldr.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", rt, sym.RelocName(arch, rt), ldr.SymName(rs), ldr.SymType(rs), ldr.SymType(rs))
 			return false
@@ -415,6 +415,22 @@ func machoreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sy
 		}
 		v |= 1 << 24 // pc-relative bit
 		v |= ld.MACHO_ARM64_RELOC_PAGE21 << 28
+	case objabi.R_ARM64_GOTPCREL:
+		siz = 4
+		// Two relocation entries: MACHO_ARM64_RELOC_GOT_LOAD_PAGEOFF12 MACHO_ARM64_RELOC_GOT_LOAD_PAGE21
+		// if r.Xadd is non-zero, add two MACHO_ARM64_RELOC_ADDEND.
+		if r.Xadd != 0 {
+			out.Write32(uint32(sectoff + 4))
+			out.Write32((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(r.Xadd&0xffffff))
+		}
+		out.Write32(uint32(sectoff + 4))
+		out.Write32(v | (ld.MACHO_ARM64_RELOC_GOT_LOAD_PAGEOFF12 << 28) | (2 << 25))
+		if r.Xadd != 0 {
+			out.Write32(uint32(sectoff))
+			out.Write32((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(r.Xadd&0xffffff))
+		}
+		v |= 1 << 24 // pc-relative bit
+		v |= ld.MACHO_ARM64_RELOC_GOT_LOAD_PAGE21 << 28
 	}
 
 	switch siz {
@@ -457,7 +473,7 @@ func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loade
 			}
 
 			nExtReloc = 2 // need two ELF/Mach-O relocations. see elfreloc1/machoreloc1
-			if target.IsDarwin() && rt == objabi.R_ADDRARM64 && xadd != 0 {
+			if target.IsDarwin() && xadd != 0 {
 				nExtReloc = 4 // need another two relocations for non-zero addend
 			}
 

src/cmd/link/internal/ld/config.go

@@ -39,7 +39,13 @@ func (mode *BuildMode) Set(s string) error {
 	case "pie":
 		switch objabi.GOOS {
 		case "aix", "android", "linux", "windows":
-		case "darwin", "freebsd":
+		case "darwin":
+			switch objabi.GOARCH {
+			case "amd64", "arm64":
+			default:
+				return badmode()
+			}
+		case "freebsd":
 			switch objabi.GOARCH {
 			case "amd64":
 			default:
@@ -95,7 +101,13 @@ func (mode *BuildMode) Set(s string) error {
 			default:
 				return badmode()
 			}
-		case "darwin", "freebsd":
+		case "darwin":
+			switch objabi.GOARCH {
+			case "amd64", "arm64":
+			default:
+				return badmode()
+			}
+		case "freebsd":
 			switch objabi.GOARCH {
 			case "amd64":
 			default:

src/cmd/link/internal/ld/dwarf_test.go

@@ -238,6 +238,10 @@ func TestSizes(t *testing.T) {
 	if runtime.GOOS == "plan9" {
 		t.Skip("skipping on plan9; no DWARF symbol table in executables")
 	}
+
+	// External linking may bring in C symbols with unknown size. Skip.
+	testenv.MustInternalLink(t)
+
 	t.Parallel()
 
 	// DWARF sizes should never be -1.
@@ -919,6 +923,7 @@ func TestAbstractOriginSanityIssue26237(t *testing.T) {
 
 func TestRuntimeTypeAttrInternal(t *testing.T) {
 	testenv.MustHaveGoBuild(t)
+	testenv.MustInternalLink(t)
 
 	if runtime.GOOS == "plan9" {
 		t.Skip("skipping on plan9; no DWARF symbol table in executables")
@@ -1018,6 +1023,9 @@ func main() {
 		t.Fatalf("*main.X DIE had no runtime type attr. DIE: %v", dies[0])
 	}
 
+	if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
+		return // everything is PIE on ARM64, addresses are relocated
+	}
 	if rtAttr.(uint64)+types.Addr != addr {
 		t.Errorf("DWARF type offset was %#x+%#x, but test program said %#x", rtAttr.(uint64), types.Addr, addr)
 	}
@@ -1203,6 +1211,15 @@ func main() {
 		}
 	}
 
+	// When external linking, we put all symbols in the symbol table (so the
+	// external linker can find them). Skip the symbol table check.
+	// TODO: maybe there is some way to tell the external linker not to put
+	// those symbols in the executable's symbol table? Prefix the symbol name
+	// with "." or "L" to pretend it is a label?
+	if !testenv.CanInternalLink() {
+		return
+	}
+
 	syms, err := f.Symbols()
 	if err != nil {
 		t.Fatalf("error reading symbols: %v", err)

src/cmd/link/internal/ld/ld_test.go

@@ -18,8 +18,13 @@ import (
 )
 
 func TestUndefinedRelocErrors(t *testing.T) {
-	t.Parallel()
 	testenv.MustHaveGoBuild(t)
+
+	// When external linking, symbols may be defined externally, so we allow
+	// undefined symbols and let external linker resolve. Skip the test.
+	testenv.MustInternalLink(t)
+
+	t.Parallel()
 	dir, err := ioutil.TempDir("", "go-build")
 	if err != nil {
 		t.Fatal(err)

src/cmd/link/internal/ld/lib.go

@@ -1254,7 +1254,9 @@ func (ctxt *Link) hostlink() {
 			// -headerpad is incompatible with -fembed-bitcode.
 			argv = append(argv, "-Wl,-headerpad,1144")
 		}
-		if ctxt.DynlinkingGo() && !ctxt.Arch.InFamily(sys.ARM, sys.ARM64) {
+		if ctxt.DynlinkingGo() && objabi.GOOS != "ios" {
+			// -flat_namespace is deprecated on iOS.
+			// It is useful for supporting plugins. We don't support plugins on iOS.
 			argv = append(argv, "-Wl,-flat_namespace")
 		}
 		if !combineDwarf {
@@ -1327,9 +1329,6 @@ func (ctxt *Link) hostlink() {
 	case BuildModeCShared:
 		if ctxt.HeadType == objabi.Hdarwin {
 			argv = append(argv, "-dynamiclib")
-			if ctxt.Arch.Family != sys.AMD64 {
-				argv = append(argv, "-Wl,-read_only_relocs,suppress")
-			}
 		} else {
 			// ELF.
 			argv = append(argv, "-Wl,-Bsymbolic")

src/cmd/link/internal/ld/macho.go

@@ -76,36 +76,38 @@ const (
 )
 
 const (
-	MACHO_CPU_AMD64               = 1<<24 | 7
+	MACHO_CPU_AMD64                      = 1<<24 | 7
-	MACHO_CPU_386                 = 7
+	MACHO_CPU_386                        = 7
-	MACHO_SUBCPU_X86              = 3
+	MACHO_SUBCPU_X86                     = 3
-	MACHO_CPU_ARM                 = 12
+	MACHO_CPU_ARM                        = 12
-	MACHO_SUBCPU_ARM              = 0
+	MACHO_SUBCPU_ARM                     = 0
-	MACHO_SUBCPU_ARMV7            = 9
+	MACHO_SUBCPU_ARMV7                   = 9
-	MACHO_CPU_ARM64               = 1<<24 | 12
+	MACHO_CPU_ARM64                      = 1<<24 | 12
-	MACHO_SUBCPU_ARM64_ALL        = 0
+	MACHO_SUBCPU_ARM64_ALL               = 0
-	MACHO32SYMSIZE                = 12
+	MACHO32SYMSIZE                       = 12
-	MACHO64SYMSIZE                = 16
+	MACHO64SYMSIZE                       = 16
-	MACHO_X86_64_RELOC_UNSIGNED   = 0
+	MACHO_X86_64_RELOC_UNSIGNED          = 0
-	MACHO_X86_64_RELOC_SIGNED     = 1
+	MACHO_X86_64_RELOC_SIGNED            = 1
-	MACHO_X86_64_RELOC_BRANCH     = 2
+	MACHO_X86_64_RELOC_BRANCH            = 2
-	MACHO_X86_64_RELOC_GOT_LOAD   = 3
+	MACHO_X86_64_RELOC_GOT_LOAD          = 3
-	MACHO_X86_64_RELOC_GOT        = 4
+	MACHO_X86_64_RELOC_GOT               = 4
-	MACHO_X86_64_RELOC_SUBTRACTOR = 5
+	MACHO_X86_64_RELOC_SUBTRACTOR        = 5
-	MACHO_X86_64_RELOC_SIGNED_1   = 6
+	MACHO_X86_64_RELOC_SIGNED_1          = 6
-	MACHO_X86_64_RELOC_SIGNED_2   = 7
+	MACHO_X86_64_RELOC_SIGNED_2          = 7
-	MACHO_X86_64_RELOC_SIGNED_4   = 8
+	MACHO_X86_64_RELOC_SIGNED_4          = 8
-	MACHO_ARM_RELOC_VANILLA       = 0
+	MACHO_ARM_RELOC_VANILLA              = 0
-	MACHO_ARM_RELOC_PAIR          = 1
+	MACHO_ARM_RELOC_PAIR                 = 1
-	MACHO_ARM_RELOC_SECTDIFF      = 2
+	MACHO_ARM_RELOC_SECTDIFF             = 2
-	MACHO_ARM_RELOC_BR24          = 5
+	MACHO_ARM_RELOC_BR24                 = 5
-	MACHO_ARM64_RELOC_UNSIGNED    = 0
+	MACHO_ARM64_RELOC_UNSIGNED           = 0
-	MACHO_ARM64_RELOC_BRANCH26    = 2
+	MACHO_ARM64_RELOC_BRANCH26           = 2
-	MACHO_ARM64_RELOC_PAGE21      = 3
+	MACHO_ARM64_RELOC_PAGE21             = 3
-	MACHO_ARM64_RELOC_PAGEOFF12   = 4
+	MACHO_ARM64_RELOC_PAGEOFF12          = 4
-	MACHO_ARM64_RELOC_ADDEND      = 10
+	MACHO_ARM64_RELOC_GOT_LOAD_PAGE21    = 5
-	MACHO_GENERIC_RELOC_VANILLA   = 0
+	MACHO_ARM64_RELOC_GOT_LOAD_PAGEOFF12 = 6
-	MACHO_FAKE_GOTPCREL           = 100
+	MACHO_ARM64_RELOC_ADDEND             = 10
+	MACHO_GENERIC_RELOC_VANILLA          = 0
+	MACHO_FAKE_GOTPCREL                  = 100
 )
 
 const (
@@ -473,6 +475,18 @@ func (ctxt *Link) domacho() {
 		sb.SetReachable(true)
 		sb.AddUint8(0)
 	}
+
+	// Do not export C symbols dynamically in plugins, as runtime C symbols like crosscall2
+	// are in pclntab and end up pointing at the host binary, breaking unwinding.
+	// See Issue #18190.
+	if ctxt.BuildMode == BuildModePlugin {
+		for _, name := range []string{"_cgo_topofstack", "__cgo_topofstack", "_cgo_panic", "crosscall2"} {
+			s := ctxt.loader.Lookup(name, 0)
+			if s != 0 {
+				ctxt.loader.SetAttrCgoExportDynamic(s, false)
+			}
+		}
+	}
 }
 
 func machoadddynlib(lib string, linkmode LinkMode) {
@@ -897,19 +911,12 @@ func machosymtab(ctxt *Link) {
 		symtab.AddUint32(ctxt.Arch, uint32(symstr.Size()))
 
 		export := machoShouldExport(ctxt, ldr, s)
-		isGoSymbol := strings.Contains(ldr.SymExtname(s), ".")
 
-		// In normal buildmodes, only add _ to C symbols, as
+		// Prefix symbol names with "_" to match the system toolchain.
-		// Go symbols have dot in the name.
+		// (We used to only prefix C symbols, which is all required for the build.
-		//
+		// But some tools don't recognize Go symbols as symbols, so we prefix them
-		// Do not export C symbols in plugins, as runtime C
+		// as well.)
-		// symbols like crosscall2 are in pclntab and end up
+		symstr.AddUint8('_')
-		// pointing at the host binary, breaking unwinding.
-		// See Issue #18190.
-		cexport := !isGoSymbol && (ctxt.BuildMode != BuildModePlugin || onlycsymbol(ldr.SymName(s)))
-		if cexport || export || isGoSymbol {
-			symstr.AddUint8('_')
-		}
 
 		// replace "·" as ".", because DTrace cannot handle it.
 		symstr.Addstring(strings.Replace(ldr.SymExtname(s), "·", ".", -1))
@@ -920,10 +927,13 @@ func machosymtab(ctxt *Link) {
 			symtab.AddUint16(ctxt.Arch, 0)                    // desc
 			symtab.AddUintXX(ctxt.Arch, 0, ctxt.Arch.PtrSize) // no value
 		} else {
-			if ldr.AttrCgoExport(s) || export {
+			if export || ldr.AttrCgoExportDynamic(s) {
-				symtab.AddUint8(0x0f)
+				symtab.AddUint8(0x0f) // N_SECT | N_EXT
+			} else if ldr.AttrCgoExportStatic(s) {
+				// Only export statically, not dynamically. (N_PEXT is like hidden visibility)
+				symtab.AddUint8(0x1f) // N_SECT | N_EXT | N_PEXT
 			} else {
-				symtab.AddUint8(0x0e)
+				symtab.AddUint8(0x0e) // N_SECT
 			}
 			o := s
 			if outer := ldr.OuterSym(o); outer != 0 {

src/cmd/link/internal/ld/pcln.go

@@ -13,7 +13,6 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
-	"strings"
 )
 
 // pclntab holds the state needed for pclntab generation.
@@ -113,23 +112,7 @@ func makePclntab(ctxt *Link, container loader.Bitmap) (*pclntab, []*sym.Compilat
 	return state, compUnits, funcs
 }
 
-// onlycsymbol looks at a symbol's name to report whether this is a
-// symbol that is referenced by C code
-func onlycsymbol(sname string) bool {
-	switch sname {
-	case "_cgo_topofstack", "__cgo_topofstack", "_cgo_panic", "crosscall2":
-		return true
-	}
-	if strings.HasPrefix(sname, "_cgoexp_") {
-		return true
-	}
-	return false
-}
-
 func emitPcln(ctxt *Link, s loader.Sym, container loader.Bitmap) bool {
-	if ctxt.BuildMode == BuildModePlugin && ctxt.HeadType == objabi.Hdarwin && onlycsymbol(ctxt.loader.SymName(s)) {
-		return false
-	}
 	// We want to generate func table entries only for the "lowest
 	// level" symbols, not containers of subsymbols.
 	return !container.Has(s)

src/cmd/link/link_test.go

@@ -181,6 +181,7 @@ main.x: relocation target main.zero not defined
 func TestIssue33979(t *testing.T) {
 	testenv.MustHaveGoBuild(t)
 	testenv.MustHaveCGO(t)
+	testenv.MustInternalLink(t)
 
 	// Skip test on platforms that do not support cgo internal linking.
 	switch runtime.GOARCH {

src/cmd/nm/nm_cgo_test.go

@@ -15,6 +15,11 @@ func canInternalLink() bool {
 	switch runtime.GOOS {
 	case "aix":
 		return false
+	case "darwin":
+		switch runtime.GOARCH {
+		case "arm64":
+			return false
+		}
 	case "dragonfly":
 		return false
 	case "freebsd":

src/cmd/nm/nm_test.go

@@ -173,6 +173,9 @@ func testGoExec(t *testing.T, iscgo, isexternallinker bool) {
 		if runtime.GOOS == "windows" {
 			return true
 		}
+		if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
+			return true // On darwin/arm64 everything is PIE
+		}
 		return false
 	}
 

src/cmd/pprof/pprof.go

@@ -171,7 +171,10 @@ func (*objTool) Demangle(names []string) (map[string]string, error) {
 	return make(map[string]string), nil
 }
 
-func (t *objTool) Disasm(file string, start, end uint64) ([]driver.Inst, error) {
+func (t *objTool) Disasm(file string, start, end uint64, intelSyntax bool) ([]driver.Inst, error) {
+	if intelSyntax {
+		return nil, fmt.Errorf("printing assembly in Intel syntax is not supported")
+	}
 	d, err := t.cachedDisasm(file)
 	if err != nil {
 		return nil, err

src/cmd/vendor/github.com/google/pprof/driver/driver.go

@@ -142,7 +142,7 @@ type ObjTool interface {
 
 	// Disasm disassembles the named object file, starting at
 	// the start address and stopping at (before) the end address.
-	Disasm(file string, start, end uint64) ([]Inst, error)
+	Disasm(file string, start, end uint64, intelSyntax bool) ([]Inst, error)
 }
 
 // An Inst is a single instruction in an assembly listing.
@@ -269,8 +269,8 @@ func (f *internalObjFile) Symbols(r *regexp.Regexp, addr uint64) ([]*plugin.Sym,
 	return pluginSyms, nil
 }
 
-func (o *internalObjTool) Disasm(file string, start, end uint64) ([]plugin.Inst, error) {
+func (o *internalObjTool) Disasm(file string, start, end uint64, intelSyntax bool) ([]plugin.Inst, error) {
-	insts, err := o.ObjTool.Disasm(file, start, end)
+	insts, err := o.ObjTool.Disasm(file, start, end, intelSyntax)
 	if err != nil {
 		return nil, err
 	}

src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go

@@ -19,6 +19,7 @@ import (
 	"debug/elf"
 	"debug/macho"
 	"encoding/binary"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -26,6 +27,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"runtime"
+	"strconv"
 	"strings"
 	"sync"
 
@@ -39,6 +41,8 @@ type Binutils struct {
 	rep *binrep
 }
 
+var objdumpLLVMVerRE = regexp.MustCompile(`LLVM version (?:(\d*)\.(\d*)\.(\d*)|.*(trunk).*)`)
+
 // binrep is an immutable representation for Binutils.  It is atomically
 // replaced on every mutation to provide thread-safe access.
 type binrep struct {
@@ -51,6 +55,7 @@ type binrep struct {
 	nmFound             bool
 	objdump             string
 	objdumpFound        bool
+	isLLVMObjdump       bool
 
 	// if fast, perform symbolization using nm (symbol names only),
 	// instead of file-line detail from the slower addr2line.
@@ -132,15 +137,103 @@ func initTools(b *binrep, config string) {
 	}
 
 	defaultPath := paths[""]
-	b.llvmSymbolizer, b.llvmSymbolizerFound = findExe("llvm-symbolizer", append(paths["llvm-symbolizer"], defaultPath...))
+	b.llvmSymbolizer, b.llvmSymbolizerFound = chooseExe([]string{"llvm-symbolizer"}, []string{}, append(paths["llvm-symbolizer"], defaultPath...))
-	b.addr2line, b.addr2lineFound = findExe("addr2line", append(paths["addr2line"], defaultPath...))
+	b.addr2line, b.addr2lineFound = chooseExe([]string{"addr2line"}, []string{"gaddr2line"}, append(paths["addr2line"], defaultPath...))
-	if !b.addr2lineFound {
+	// The "-n" option is supported by LLVM since 2011. The output of llvm-nm
-		// On MacOS, brew installs addr2line under gaddr2line name, so search for
+	// and GNU nm with "-n" option is interchangeable for our purposes, so we do
-		// that if the tool is not found by its default name.
+	// not need to differrentiate them.
-		b.addr2line, b.addr2lineFound = findExe("gaddr2line", append(paths["addr2line"], defaultPath...))
+	b.nm, b.nmFound = chooseExe([]string{"llvm-nm", "nm"}, []string{"gnm"}, append(paths["nm"], defaultPath...))
+	b.objdump, b.objdumpFound, b.isLLVMObjdump = findObjdump(append(paths["objdump"], defaultPath...))
+}
+
+// findObjdump finds and returns path to preferred objdump binary.
+// Order of preference is: llvm-objdump, objdump.
+// On MacOS only, also looks for gobjdump with least preference.
+// Accepts a list of paths and returns:
+// a string with path to the preferred objdump binary if found,
+// or an empty string if not found;
+// a boolean if any acceptable objdump was found;
+// a boolean indicating if it is an LLVM objdump.
+func findObjdump(paths []string) (string, bool, bool) {
+	objdumpNames := []string{"llvm-objdump", "objdump"}
+	if runtime.GOOS == "darwin" {
+		objdumpNames = append(objdumpNames, "gobjdump")
 	}
-	b.nm, b.nmFound = findExe("nm", append(paths["nm"], defaultPath...))
+
-	b.objdump, b.objdumpFound = findExe("objdump", append(paths["objdump"], defaultPath...))
+	for _, objdumpName := range objdumpNames {
+		if objdump, objdumpFound := findExe(objdumpName, paths); objdumpFound {
+			cmdOut, err := exec.Command(objdump, "--version").Output()
+			if err != nil {
+				continue
+			}
+			if isLLVMObjdump(string(cmdOut)) {
+				return objdump, true, true
+			}
+			if isBuObjdump(string(cmdOut)) {
+				return objdump, true, false
+			}
+		}
+	}
+	return "", false, false
+}
+
+// chooseExe finds and returns path to preferred binary. names is a list of
+// names to search on both Linux and OSX. osxNames is a list of names specific
+// to OSX. names always has a higher priority than osxNames. The order of
+// the name within each list decides its priority (e.g. the first name has a
+// higher priority than the second name in the list).
+//
+// It returns a string with path to the binary and a boolean indicating if any
+// acceptable binary was found.
+func chooseExe(names, osxNames []string, paths []string) (string, bool) {
+	if runtime.GOOS == "darwin" {
+		names = append(names, osxNames...)
+	}
+	for _, name := range names {
+		if binary, found := findExe(name, paths); found {
+			return binary, true
+		}
+	}
+	return "", false
+}
+
+// isLLVMObjdump accepts a string with path to an objdump binary,
+// and returns a boolean indicating if the given binary is an LLVM
+// objdump binary of an acceptable version.
+func isLLVMObjdump(output string) bool {
+	fields := objdumpLLVMVerRE.FindStringSubmatch(output)
+	if len(fields) != 5 {
+		return false
+	}
+	if fields[4] == "trunk" {
+		return true
+	}
+	verMajor, err := strconv.Atoi(fields[1])
+	if err != nil {
+		return false
+	}
+	verPatch, err := strconv.Atoi(fields[3])
+	if err != nil {
+		return false
+	}
+	if runtime.GOOS == "linux" && verMajor >= 8 {
+		// Ensure LLVM objdump is at least version 8.0 on Linux.
+		// Some flags, like --demangle, and double dashes for options are
+		// not supported by previous versions.
+		return true
+	}
+	if runtime.GOOS == "darwin" {
+		// Ensure LLVM objdump is at least version 10.0.1 on MacOS.
+		return verMajor > 10 || (verMajor == 10 && verPatch >= 1)
+	}
+	return false
+}
+
+// isBuObjdump accepts a string with path to an objdump binary,
+// and returns a boolean indicating if the given binary is a GNU
+// binutils objdump binary. No version check is performed.
+func isBuObjdump(output string) bool {
+	return strings.Contains(output, "GNU objdump")
 }
 
 // findExe looks for an executable command on a set of paths.
@@ -157,12 +250,25 @@ func findExe(cmd string, paths []string) (string, bool) {
 
 // Disasm returns the assembly instructions for the specified address range
 // of a binary.
-func (bu *Binutils) Disasm(file string, start, end uint64) ([]plugin.Inst, error) {
+func (bu *Binutils) Disasm(file string, start, end uint64, intelSyntax bool) ([]plugin.Inst, error) {
 	b := bu.get()
-	cmd := exec.Command(b.objdump, "-d", "-C", "--no-show-raw-insn", "-l",
+	if !b.objdumpFound {
-		fmt.Sprintf("--start-address=%#x", start),
+		return nil, errors.New("cannot disasm: no objdump tool available")
-		fmt.Sprintf("--stop-address=%#x", end),
+	}
-		file)
+	args := []string{"--disassemble-all", "--demangle", "--no-show-raw-insn",
+		"--line-numbers", fmt.Sprintf("--start-address=%#x", start),
+		fmt.Sprintf("--stop-address=%#x", end)}
+
+	if intelSyntax {
+		if b.isLLVMObjdump {
+			args = append(args, "--x86-asm-syntax=intel")
+		} else {
+			args = append(args, "-M", "intel")
+		}
+	}
+
+	args = append(args, file)
+	cmd := exec.Command(b.objdump, args...)
 	out, err := cmd.Output()
 	if err != nil {
 		return nil, fmt.Errorf("%v: %v", cmd.Args, err)

src/cmd/vendor/github.com/google/pprof/internal/binutils/disasm.go

@@ -25,10 +25,11 @@ import (
 )
 
 var (
-	nmOutputRE            = regexp.MustCompile(`^\s*([[:xdigit:]]+)\s+(.)\s+(.*)`)
+	nmOutputRE                = regexp.MustCompile(`^\s*([[:xdigit:]]+)\s+(.)\s+(.*)`)
-	objdumpAsmOutputRE    = regexp.MustCompile(`^\s*([[:xdigit:]]+):\s+(.*)`)
+	objdumpAsmOutputRE        = regexp.MustCompile(`^\s*([[:xdigit:]]+):\s+(.*)`)
-	objdumpOutputFileLine = regexp.MustCompile(`^(.*):([0-9]+)`)
+	objdumpOutputFileLine     = regexp.MustCompile(`^;?\s?(.*):([0-9]+)`)
-	objdumpOutputFunction = regexp.MustCompile(`^(\S.*)\(\):`)
+	objdumpOutputFunction     = regexp.MustCompile(`^;?\s?(\S.*)\(\):`)
+	objdumpOutputFunctionLLVM = regexp.MustCompile(`^([[:xdigit:]]+)?\s?(.*):`)
 )
 
 func findSymbols(syms []byte, file string, r *regexp.Regexp, address uint64) ([]*plugin.Sym, error) {
@@ -143,6 +144,11 @@ func disassemble(asm []byte) ([]plugin.Inst, error) {
 		if fields := objdumpOutputFunction.FindStringSubmatch(input); len(fields) == 2 {
 			function = fields[1]
 			continue
+		} else {
+			if fields := objdumpOutputFunctionLLVM.FindStringSubmatch(input); len(fields) == 3 {
+				function = fields[2]
+				continue
+			}
 		}
 		// Reset on unrecognized lines.
 		function, file, line = "", "", 0

src/cmd/vendor/github.com/google/pprof/internal/driver/cli.go

@@ -69,8 +69,9 @@ func parseFlags(o *plugin.Options) (*source, []string, error) {
 	flagHTTP := flag.String("http", "", "Present interactive web UI at the specified http host:port")
 	flagNoBrowser := flag.Bool("no_browser", false, "Skip opening a browswer for the interactive web UI")
 
-	// Flags used during command processing
+	// Flags that set configuration properties.
-	installedFlags := installFlags(flag)
+	cfg := currentConfig()
+	configFlagSetter := installConfigFlags(flag, &cfg)
 
 	flagCommands := make(map[string]*bool)
 	flagParamCommands := make(map[string]*string)
@@ -107,8 +108,8 @@ func parseFlags(o *plugin.Options) (*source, []string, error) {
 		}
 	}
 
-	// Report conflicting options
+	// Apply any specified flags to cfg.
-	if err := updateFlags(installedFlags); err != nil {
+	if err := configFlagSetter(); err != nil {
 		return nil, nil, err
 	}
 
@@ -124,7 +125,7 @@ func parseFlags(o *plugin.Options) (*source, []string, error) {
 		return nil, nil, errors.New("-no_browser only makes sense with -http")
 	}
 
-	si := pprofVariables["sample_index"].value
+	si := cfg.SampleIndex
 	si = sampleIndex(flagTotalDelay, si, "delay", "-total_delay", o.UI)
 	si = sampleIndex(flagMeanDelay, si, "delay", "-mean_delay", o.UI)
 	si = sampleIndex(flagContentions, si, "contentions", "-contentions", o.UI)
@@ -132,10 +133,10 @@ func parseFlags(o *plugin.Options) (*source, []string, error) {
 	si = sampleIndex(flagInUseObjects, si, "inuse_objects", "-inuse_objects", o.UI)
 	si = sampleIndex(flagAllocSpace, si, "alloc_space", "-alloc_space", o.UI)
 	si = sampleIndex(flagAllocObjects, si, "alloc_objects", "-alloc_objects", o.UI)
-	pprofVariables.set("sample_index", si)
+	cfg.SampleIndex = si
 
 	if *flagMeanDelay {
-		pprofVariables.set("mean", "true")
+		cfg.Mean = true
 	}
 
 	source := &source{
@@ -154,7 +155,7 @@ func parseFlags(o *plugin.Options) (*source, []string, error) {
 		return nil, nil, err
 	}
 
-	normalize := pprofVariables["normalize"].boolValue()
+	normalize := cfg.Normalize
 	if normalize && len(source.Base) == 0 {
 		return nil, nil, errors.New("must have base profile to normalize by")
 	}
@@ -163,6 +164,8 @@ func parseFlags(o *plugin.Options) (*source, []string, error) {
 	if bu, ok := o.Obj.(*binutils.Binutils); ok {
 		bu.SetTools(*flagTools)
 	}
+
+	setCurrentConfig(cfg)
 	return source, cmd, nil
 }
 
@@ -194,66 +197,72 @@ func dropEmpty(list []*string) []string {
 	return l
 }
 
-// installFlags creates command line flags for pprof variables.
+// installConfigFlags creates command line flags for configuration
-func installFlags(flag plugin.FlagSet) flagsInstalled {
+// fields and returns a function which can be called after flags have
-	f := flagsInstalled{
+// been parsed to copy any flags specified on the command line to
-		ints:    make(map[string]*int),
+// *cfg.
-		bools:   make(map[string]*bool),
+func installConfigFlags(flag plugin.FlagSet, cfg *config) func() error {
-		floats:  make(map[string]*float64),
+	// List of functions for setting the different parts of a config.
-		strings: make(map[string]*string),
+	var setters []func()
-	}
+	var err error // Holds any errors encountered while running setters.
-	for n, v := range pprofVariables {
+
-		switch v.kind {
+	for _, field := range configFields {
-		case boolKind:
+		n := field.name
-			if v.group != "" {
+		help := configHelp[n]
-				// Set all radio variables to false to identify conflicts.
+		var setter func()
-				f.bools[n] = flag.Bool(n, false, v.help)
+		switch ptr := cfg.fieldPtr(field).(type) {
+		case *bool:
+			f := flag.Bool(n, *ptr, help)
+			setter = func() { *ptr = *f }
+		case *int:
+			f := flag.Int(n, *ptr, help)
+			setter = func() { *ptr = *f }
+		case *float64:
+			f := flag.Float64(n, *ptr, help)
+			setter = func() { *ptr = *f }
+		case *string:
+			if len(field.choices) == 0 {
+				f := flag.String(n, *ptr, help)
+				setter = func() { *ptr = *f }
 			} else {
-				f.bools[n] = flag.Bool(n, v.boolValue(), v.help)
+				// Make a separate flag per possible choice.
+				// Set all flags to initially false so we can
+				// identify conflicts.
+				bools := make(map[string]*bool)
+				for _, choice := range field.choices {
+					bools[choice] = flag.Bool(choice, false, configHelp[choice])
+				}
+				setter = func() {
+					var set []string
+					for k, v := range bools {
+						if *v {
+							set = append(set, k)
+						}
+					}
+					switch len(set) {
+					case 0:
+						// Leave as default value.
+					case 1:
+						*ptr = set[0]
+					default:
+						err = fmt.Errorf("conflicting options set: %v", set)
+					}
+				}
 			}
-		case intKind:
-			f.ints[n] = flag.Int(n, v.intValue(), v.help)
-		case floatKind:
-			f.floats[n] = flag.Float64(n, v.floatValue(), v.help)
-		case stringKind:
-			f.strings[n] = flag.String(n, v.value, v.help)
 		}
+		setters = append(setters, setter)
 	}
-	return f
-}
 
-// updateFlags updates the pprof variables according to the flags
+	return func() error {
-// parsed in the command line.
+		// Apply the setter for every flag.
-func updateFlags(f flagsInstalled) error {
+		for _, setter := range setters {
-	vars := pprofVariables
+			setter()
-	groups := map[string]string{}
+			if err != nil {
-	for n, v := range f.bools {
+				return err
-		vars.set(n, fmt.Sprint(*v))
-		if *v {
-			g := vars[n].group
-			if g != "" && groups[g] != "" {
-				return fmt.Errorf("conflicting options %q and %q set", n, groups[g])
 			}
-			groups[g] = n
 		}
+		return nil
 	}
-	for n, v := range f.ints {
-		vars.set(n, fmt.Sprint(*v))
-	}
-	for n, v := range f.floats {
-		vars.set(n, fmt.Sprint(*v))
-	}
-	for n, v := range f.strings {
-		vars.set(n, *v)
-	}
-	return nil
-}
-
-type flagsInstalled struct {
-	ints    map[string]*int
-	bools   map[string]*bool
-	floats  map[string]*float64
-	strings map[string]*string
 }
 
 // isBuildID determines if the profile may contain a build ID, by

src/cmd/vendor/github.com/google/pprof/internal/driver/commands.go

@@ -22,7 +22,6 @@ import (
 	"os/exec"
 	"runtime"
 	"sort"
-	"strconv"
 	"strings"
 	"time"
 
@@ -70,9 +69,7 @@ func AddCommand(cmd string, format int, post PostProcessor, desc, usage string)
 // SetVariableDefault sets the default value for a pprof
 // variable. This enables extensions to set their own defaults.
 func SetVariableDefault(variable, value string) {
-	if v := pprofVariables[variable]; v != nil {
+	configure(variable, value)
-		v.value = value
-	}
 }
 
 // PostProcessor is a function that applies post-processing to the report output
@@ -124,130 +121,132 @@ var pprofCommands = commands{
 	"weblist": {report.WebList, nil, invokeVisualizer("html", browsers()), true, "Display annotated source in a web browser", listHelp("weblist", false)},
 }
 
-// pprofVariables are the configuration parameters that affect the
+// configHelp contains help text per configuration parameter.
-// reported generated by pprof.
+var configHelp = map[string]string{
-var pprofVariables = variables{
 	// Filename for file-based output formats, stdout by default.
-	"output": &variable{stringKind, "", "", helpText("Output filename for file-based outputs")},
+	"output": helpText("Output filename for file-based outputs"),
 
 	// Comparisons.
-	"drop_negative": &variable{boolKind, "f", "", helpText(
+	"drop_negative": helpText(
 		"Ignore negative differences",
-		"Do not show any locations with values <0.")},
+		"Do not show any locations with values <0."),
 
 	// Graph handling options.
-	"call_tree": &variable{boolKind, "f", "", helpText(
+	"call_tree": helpText(
 		"Create a context-sensitive call tree",
-		"Treat locations reached through different paths as separate.")},
+		"Treat locations reached through different paths as separate."),
 
 	// Display options.
-	"relative_percentages": &variable{boolKind, "f", "", helpText(
+	"relative_percentages": helpText(
 		"Show percentages relative to focused subgraph",
 		"If unset, percentages are relative to full graph before focusing",
-		"to facilitate comparison with original graph.")},
+		"to facilitate comparison with original graph."),
-	"unit": &variable{stringKind, "minimum", "", helpText(
+	"unit": helpText(
 		"Measurement units to display",
 		"Scale the sample values to this unit.",
 		"For time-based profiles, use seconds, milliseconds, nanoseconds, etc.",
 		"For memory profiles, use megabytes, kilobytes, bytes, etc.",
-		"Using auto will scale each value independently to the most natural unit.")},
+		"Using auto will scale each value independently to the most natural unit."),
-	"compact_labels": &variable{boolKind, "f", "", "Show minimal headers"},
+	"compact_labels": "Show minimal headers",
-	"source_path":    &variable{stringKind, "", "", "Search path for source files"},
+	"source_path":    "Search path for source files",
-	"trim_path":      &variable{stringKind, "", "", "Path to trim from source paths before search"},
+	"trim_path":      "Path to trim from source paths before search",
+	"intel_syntax": helpText(
+		"Show assembly in Intel syntax",
+		"Only applicable to commands `disasm` and `weblist`"),
 
 	// Filtering options
-	"nodecount": &variable{intKind, "-1", "", helpText(
+	"nodecount": helpText(
 		"Max number of nodes to show",
 		"Uses heuristics to limit the number of locations to be displayed.",
-		"On graphs, dotted edges represent paths through nodes that have been removed.")},
+		"On graphs, dotted edges represent paths through nodes that have been removed."),
-	"nodefraction": &variable{floatKind, "0.005", "", "Hide nodes below <f>*total"},
+	"nodefraction": "Hide nodes below <f>*total",
-	"edgefraction": &variable{floatKind, "0.001", "", "Hide edges below <f>*total"},
+	"edgefraction": "Hide edges below <f>*total",
-	"trim": &variable{boolKind, "t", "", helpText(
+	"trim": helpText(
 		"Honor nodefraction/edgefraction/nodecount defaults",
-		"Set to false to get the full profile, without any trimming.")},
+		"Set to false to get the full profile, without any trimming."),
-	"focus": &variable{stringKind, "", "", helpText(
+	"focus": helpText(
 		"Restricts to samples going through a node matching regexp",
 		"Discard samples that do not include a node matching this regexp.",
-		"Matching includes the function name, filename or object name.")},
+		"Matching includes the function name, filename or object name."),
-	"ignore": &variable{stringKind, "", "", helpText(
+	"ignore": helpText(
 		"Skips paths going through any nodes matching regexp",
 		"If set, discard samples that include a node matching this regexp.",
-		"Matching includes the function name, filename or object name.")},
+		"Matching includes the function name, filename or object name."),
-	"prune_from": &variable{stringKind, "", "", helpText(
+	"prune_from": helpText(
 		"Drops any functions below the matched frame.",
 		"If set, any frames matching the specified regexp and any frames",
-		"below it will be dropped from each sample.")},
+		"below it will be dropped from each sample."),
-	"hide": &variable{stringKind, "", "", helpText(
+	"hide": helpText(
 		"Skips nodes matching regexp",
 		"Discard nodes that match this location.",
 		"Other nodes from samples that include this location will be shown.",
-		"Matching includes the function name, filename or object name.")},
+		"Matching includes the function name, filename or object name."),
-	"show": &variable{stringKind, "", "", helpText(
+	"show": helpText(
 		"Only show nodes matching regexp",
 		"If set, only show nodes that match this location.",
-		"Matching includes the function name, filename or object name.")},
+		"Matching includes the function name, filename or object name."),
-	"show_from": &variable{stringKind, "", "", helpText(
+	"show_from": helpText(
 		"Drops functions above the highest matched frame.",
 		"If set, all frames above the highest match are dropped from every sample.",
-		"Matching includes the function name, filename or object name.")},
+		"Matching includes the function name, filename or object name."),
-	"tagfocus": &variable{stringKind, "", "", helpText(
+	"tagfocus": helpText(
 		"Restricts to samples with tags in range or matched by regexp",
 		"Use name=value syntax to limit the matching to a specific tag.",
 		"Numeric tag filter examples: 1kb, 1kb:10kb, memory=32mb:",
-		"String tag filter examples: foo, foo.*bar, mytag=foo.*bar")},
+		"String tag filter examples: foo, foo.*bar, mytag=foo.*bar"),
-	"tagignore": &variable{stringKind, "", "", helpText(
+	"tagignore": helpText(
 		"Discard samples with tags in range or matched by regexp",
 		"Use name=value syntax to limit the matching to a specific tag.",
 		"Numeric tag filter examples: 1kb, 1kb:10kb, memory=32mb:",
-		"String tag filter examples: foo, foo.*bar, mytag=foo.*bar")},
+		"String tag filter examples: foo, foo.*bar, mytag=foo.*bar"),
-	"tagshow": &variable{stringKind, "", "", helpText(
+	"tagshow": helpText(
 		"Only consider tags matching this regexp",
-		"Discard tags that do not match this regexp")},
+		"Discard tags that do not match this regexp"),
-	"taghide": &variable{stringKind, "", "", helpText(
+	"taghide": helpText(
 		"Skip tags matching this regexp",
-		"Discard tags that match this regexp")},
+		"Discard tags that match this regexp"),
 	// Heap profile options
-	"divide_by": &variable{floatKind, "1", "", helpText(
+	"divide_by": helpText(
 		"Ratio to divide all samples before visualization",
-		"Divide all samples values by a constant, eg the number of processors or jobs.")},
+		"Divide all samples values by a constant, eg the number of processors or jobs."),
-	"mean": &variable{boolKind, "f", "", helpText(
+	"mean": helpText(
 		"Average sample value over first value (count)",
 		"For memory profiles, report average memory per allocation.",
-		"For time-based profiles, report average time per event.")},
+		"For time-based profiles, report average time per event."),
-	"sample_index": &variable{stringKind, "", "", helpText(
+	"sample_index": helpText(
 		"Sample value to report (0-based index or name)",
 		"Profiles contain multiple values per sample.",
-		"Use sample_index=i to select the ith value (starting at 0).")},
+		"Use sample_index=i to select the ith value (starting at 0)."),
-	"normalize": &variable{boolKind, "f", "", helpText(
+	"normalize": helpText(
-		"Scales profile based on the base profile.")},
+		"Scales profile based on the base profile."),
 
 	// Data sorting criteria
-	"flat": &variable{boolKind, "t", "cumulative", helpText("Sort entries based on own weight")},
+	"flat": helpText("Sort entries based on own weight"),
-	"cum":  &variable{boolKind, "f", "cumulative", helpText("Sort entries based on cumulative weight")},
+	"cum":  helpText("Sort entries based on cumulative weight"),
 
 	// Output granularity
-	"functions": &variable{boolKind, "t", "granularity", helpText(
+	"functions": helpText(
 		"Aggregate at the function level.",
-		"Ignores the filename where the function was defined.")},
+		"Ignores the filename where the function was defined."),
-	"filefunctions": &variable{boolKind, "t", "granularity", helpText(
+	"filefunctions": helpText(
 		"Aggregate at the function level.",
-		"Takes into account the filename where the function was defined.")},
+		"Takes into account the filename where the function was defined."),
-	"files": &variable{boolKind, "f", "granularity", "Aggregate at the file level."},
+	"files": "Aggregate at the file level.",
-	"lines": &variable{boolKind, "f", "granularity", "Aggregate at the source code line level."},
+	"lines": "Aggregate at the source code line level.",
-	"addresses": &variable{boolKind, "f", "granularity", helpText(
+	"addresses": helpText(
 		"Aggregate at the address level.",
-		"Includes functions' addresses in the output.")},
+		"Includes functions' addresses in the output."),
-	"noinlines": &variable{boolKind, "f", "", helpText(
+	"noinlines": helpText(
 		"Ignore inlines.",
-		"Attributes inlined functions to their first out-of-line caller.")},
+		"Attributes inlined functions to their first out-of-line caller."),
 }
 
 func helpText(s ...string) string {
 	return strings.Join(s, "\n") + "\n"
 }
 
-// usage returns a string describing the pprof commands and variables.
+// usage returns a string describing the pprof commands and configuration
-// if commandLine is set, the output reflect cli usage.
+// options.  if commandLine is set, the output reflect cli usage.
 func usage(commandLine bool) string {
 	var prefix string
 	if commandLine {
@@ -269,40 +268,33 @@ func usage(commandLine bool) string {
 	} else {
 		help = "  Commands:\n"
 		commands = append(commands, fmtHelp("o/options", "List options and their current values"))
-		commands = append(commands, fmtHelp("quit/exit/^D", "Exit pprof"))
+		commands = append(commands, fmtHelp("q/quit/exit/^D", "Exit pprof"))
 	}
 
 	help = help + strings.Join(commands, "\n") + "\n\n" +
 		"  Options:\n"
 
-	// Print help for variables after sorting them.
+	// Print help for configuration options after sorting them.
-	// Collect radio variables by their group name to print them together.
+	// Collect choices for multi-choice options print them together.
-	radioOptions := make(map[string][]string)
 	var variables []string
-	for name, vr := range pprofVariables {
+	var radioStrings []string
-		if vr.group != "" {
+	for _, f := range configFields {
-			radioOptions[vr.group] = append(radioOptions[vr.group], name)
+		if len(f.choices) == 0 {
+			variables = append(variables, fmtHelp(prefix+f.name, configHelp[f.name]))
 			continue
 		}
-		variables = append(variables, fmtHelp(prefix+name, vr.help))
+		// Format help for for this group.
-	}
+		s := []string{fmtHelp(f.name, "")}
-	sort.Strings(variables)
+		for _, choice := range f.choices {
-
+			s = append(s, "  "+fmtHelp(prefix+choice, configHelp[choice]))
-	help = help + strings.Join(variables, "\n") + "\n\n" +
-		"  Option groups (only set one per group):\n"
-
-	var radioStrings []string
-	for radio, ops := range radioOptions {
-		sort.Strings(ops)
-		s := []string{fmtHelp(radio, "")}
-		for _, op := range ops {
-			s = append(s, "  "+fmtHelp(prefix+op, pprofVariables[op].help))
 		}
-
 		radioStrings = append(radioStrings, strings.Join(s, "\n"))
 	}
+	sort.Strings(variables)
 	sort.Strings(radioStrings)
-	return help + strings.Join(radioStrings, "\n")
+	return help + strings.Join(variables, "\n") + "\n\n" +
+		"  Option groups (only set one per group):\n" +
+		strings.Join(radioStrings, "\n")
 }
 
 func reportHelp(c string, cum, redirect bool) string {
@@ -445,105 +437,8 @@ func invokeVisualizer(suffix string, visualizers []string) PostProcessor {
 	}
 }
 
-// variables describe the configuration parameters recognized by pprof.
+// stringToBool is a custom parser for bools. We avoid using strconv.ParseBool
-type variables map[string]*variable
+// to remain compatible with old pprof behavior (e.g., treating "" as true).
-
-// variable is a single configuration parameter.
-type variable struct {
-	kind  int    // How to interpret the value, must be one of the enums below.
-	value string // Effective value. Only values appropriate for the Kind should be set.
-	group string // boolKind variables with the same Group != "" cannot be set simultaneously.
-	help  string // Text describing the variable, in multiple lines separated by newline.
-}
-
-const (
-	// variable.kind must be one of these variables.
-	boolKind = iota
-	intKind
-	floatKind
-	stringKind
-)
-
-// set updates the value of a variable, checking that the value is
-// suitable for the variable Kind.
-func (vars variables) set(name, value string) error {
-	v := vars[name]
-	if v == nil {
-		return fmt.Errorf("no variable %s", name)
-	}
-	var err error
-	switch v.kind {
-	case boolKind:
-		var b bool
-		if b, err = stringToBool(value); err == nil {
-			if v.group != "" && !b {
-				err = fmt.Errorf("%q can only be set to true", name)
-			}
-		}
-	case intKind:
-		_, err = strconv.Atoi(value)
-	case floatKind:
-		_, err = strconv.ParseFloat(value, 64)
-	case stringKind:
-		// Remove quotes, particularly useful for empty values.
-		if len(value) > 1 && strings.HasPrefix(value, `"`) && strings.HasSuffix(value, `"`) {
-			value = value[1 : len(value)-1]
-		}
-	}
-	if err != nil {
-		return err
-	}
-	vars[name].value = value
-	if group := vars[name].group; group != "" {
-		for vname, vvar := range vars {
-			if vvar.group == group && vname != name {
-				vvar.value = "f"
-			}
-		}
-	}
-	return err
-}
-
-// boolValue returns the value of a boolean variable.
-func (v *variable) boolValue() bool {
-	b, err := stringToBool(v.value)
-	if err != nil {
-		panic("unexpected value " + v.value + " for bool ")
-	}
-	return b
-}
-
-// intValue returns the value of an intKind variable.
-func (v *variable) intValue() int {
-	i, err := strconv.Atoi(v.value)
-	if err != nil {
-		panic("unexpected value " + v.value + " for int ")
-	}
-	return i
-}
-
-// floatValue returns the value of a Float variable.
-func (v *variable) floatValue() float64 {
-	f, err := strconv.ParseFloat(v.value, 64)
-	if err != nil {
-		panic("unexpected value " + v.value + " for float ")
-	}
-	return f
-}
-
-// stringValue returns a canonical representation for a variable.
-func (v *variable) stringValue() string {
-	switch v.kind {
-	case boolKind:
-		return fmt.Sprint(v.boolValue())
-	case intKind:
-		return fmt.Sprint(v.intValue())
-	case floatKind:
-		return fmt.Sprint(v.floatValue())
-	}
-	return v.value
-}
-
 func stringToBool(s string) (bool, error) {
 	switch strings.ToLower(s) {
 	case "true", "t", "yes", "y", "1", "":
@@ -554,13 +449,3 @@ func stringToBool(s string) (bool, error) {
 		return false, fmt.Errorf(`illegal value "%s" for bool variable`, s)
 	}
 }
-
-// makeCopy returns a duplicate of a set of shell variables.
-func (vars variables) makeCopy() variables {
-	varscopy := make(variables, len(vars))
-	for n, v := range vars {
-		vcopy := *v
-		varscopy[n] = &vcopy
-	}
-	return varscopy
-}

src/cmd/vendor/github.com/google/pprof/internal/driver/config.go

@@ -0,0 +1,367 @@
+package driver
+
+import (
+	"fmt"
+	"net/url"
+	"reflect"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+// config holds settings for a single named config.
+// The JSON tag name for a field is used both for JSON encoding and as
+// a named variable.
+type config struct {
+	// Filename for file-based output formats, stdout by default.
+	Output string `json:"-"`
+
+	// Display options.
+	CallTree            bool    `json:"call_tree,omitempty"`
+	RelativePercentages bool    `json:"relative_percentages,omitempty"`
+	Unit                string  `json:"unit,omitempty"`
+	CompactLabels       bool    `json:"compact_labels,omitempty"`
+	SourcePath          string  `json:"-"`
+	TrimPath            string  `json:"-"`
+	IntelSyntax         bool    `json:"intel_syntax,omitempty"`
+	Mean                bool    `json:"mean,omitempty"`
+	SampleIndex         string  `json:"-"`
+	DivideBy            float64 `json:"-"`
+	Normalize           bool    `json:"normalize,omitempty"`
+	Sort                string  `json:"sort,omitempty"`
+
+	// Filtering options
+	DropNegative bool    `json:"drop_negative,omitempty"`
+	NodeCount    int     `json:"nodecount,omitempty"`
+	NodeFraction float64 `json:"nodefraction,omitempty"`
+	EdgeFraction float64 `json:"edgefraction,omitempty"`
+	Trim         bool    `json:"trim,omitempty"`
+	Focus        string  `json:"focus,omitempty"`
+	Ignore       string  `json:"ignore,omitempty"`
+	PruneFrom    string  `json:"prune_from,omitempty"`
+	Hide         string  `json:"hide,omitempty"`
+	Show         string  `json:"show,omitempty"`
+	ShowFrom     string  `json:"show_from,omitempty"`
+	TagFocus     string  `json:"tagfocus,omitempty"`
+	TagIgnore    string  `json:"tagignore,omitempty"`
+	TagShow      string  `json:"tagshow,omitempty"`
+	TagHide      string  `json:"taghide,omitempty"`
+	NoInlines    bool    `json:"noinlines,omitempty"`
+
+	// Output granularity
+	Granularity string `json:"granularity,omitempty"`
+}
+
+// defaultConfig returns the default configuration values; it is unaffected by
+// flags and interactive assignments.
+func defaultConfig() config {
+	return config{
+		Unit:         "minimum",
+		NodeCount:    -1,
+		NodeFraction: 0.005,
+		EdgeFraction: 0.001,
+		Trim:         true,
+		DivideBy:     1.0,
+		Sort:         "flat",
+		Granularity:  "functions",
+	}
+}
+
+// currentConfig holds the current configuration values; it is affected by
+// flags and interactive assignments.
+var currentCfg = defaultConfig()
+var currentMu sync.Mutex
+
+func currentConfig() config {
+	currentMu.Lock()
+	defer currentMu.Unlock()
+	return currentCfg
+}
+
+func setCurrentConfig(cfg config) {
+	currentMu.Lock()
+	defer currentMu.Unlock()
+	currentCfg = cfg
+}
+
+// configField contains metadata for a single configuration field.
+type configField struct {
+	name         string              // JSON field name/key in variables
+	urlparam     string              // URL parameter name
+	saved        bool                // Is field saved in settings?
+	field        reflect.StructField // Field in config
+	choices      []string            // Name Of variables in group
+	defaultValue string              // Default value for this field.
+}
+
+var (
+	configFields []configField // Precomputed metadata per config field
+
+	// configFieldMap holds an entry for every config field as well as an
+	// entry for every valid choice for a multi-choice field.
+	configFieldMap map[string]configField
+)
+
+func init() {
+	// Config names for fields that are not saved in settings and therefore
+	// do not have a JSON name.
+	notSaved := map[string]string{
+		// Not saved in settings, but present in URLs.
+		"SampleIndex": "sample_index",
+
+		// Following fields are also not placed in URLs.
+		"Output":     "output",
+		"SourcePath": "source_path",
+		"TrimPath":   "trim_path",
+		"DivideBy":   "divide_by",
+	}
+
+	// choices holds the list of allowed values for config fields that can
+	// take on one of a bounded set of values.
+	choices := map[string][]string{
+		"sort":        {"cum", "flat"},
+		"granularity": {"functions", "filefunctions", "files", "lines", "addresses"},
+	}
+
+	// urlparam holds the mapping from a config field name to the URL
+	// parameter used to hold that config field. If no entry is present for
+	// a name, the corresponding field is not saved in URLs.
+	urlparam := map[string]string{
+		"drop_negative":        "dropneg",
+		"call_tree":            "calltree",
+		"relative_percentages": "rel",
+		"unit":                 "unit",
+		"compact_labels":       "compact",
+		"intel_syntax":         "intel",
+		"nodecount":            "n",
+		"nodefraction":         "nf",
+		"edgefraction":         "ef",
+		"trim":                 "trim",
+		"focus":                "f",
+		"ignore":               "i",
+		"prune_from":           "prunefrom",
+		"hide":                 "h",
+		"show":                 "s",
+		"show_from":            "sf",
+		"tagfocus":             "tf",
+		"tagignore":            "ti",
+		"tagshow":              "ts",
+		"taghide":              "th",
+		"mean":                 "mean",
+		"sample_index":         "si",
+		"normalize":            "norm",
+		"sort":                 "sort",
+		"granularity":          "g",
+		"noinlines":            "noinlines",
+	}
+
+	def := defaultConfig()
+	configFieldMap = map[string]configField{}
+	t := reflect.TypeOf(config{})
+	for i, n := 0, t.NumField(); i < n; i++ {
+		field := t.Field(i)
+		js := strings.Split(field.Tag.Get("json"), ",")
+		if len(js) == 0 {
+			continue
+		}
+		// Get the configuration name for this field.
+		name := js[0]
+		if name == "-" {
+			name = notSaved[field.Name]
+			if name == "" {
+				// Not a configurable field.
+				continue
+			}
+		}
+		f := configField{
+			name:     name,
+			urlparam: urlparam[name],
+			saved:    (name == js[0]),
+			field:    field,
+			choices:  choices[name],
+		}
+		f.defaultValue = def.get(f)
+		configFields = append(configFields, f)
+		configFieldMap[f.name] = f
+		for _, choice := range f.choices {
+			configFieldMap[choice] = f
+		}
+	}
+}
+
+// fieldPtr returns a pointer to the field identified by f in *cfg.
+func (cfg *config) fieldPtr(f configField) interface{} {
+	// reflect.ValueOf: converts to reflect.Value
+	// Elem: dereferences cfg to make *cfg
+	// FieldByIndex: fetches the field
+	// Addr: takes address of field
+	// Interface: converts back from reflect.Value to a regular value
+	return reflect.ValueOf(cfg).Elem().FieldByIndex(f.field.Index).Addr().Interface()
+}
+
+// get returns the value of field f in cfg.
+func (cfg *config) get(f configField) string {
+	switch ptr := cfg.fieldPtr(f).(type) {
+	case *string:
+		return *ptr
+	case *int:
+		return fmt.Sprint(*ptr)
+	case *float64:
+		return fmt.Sprint(*ptr)
+	case *bool:
+		return fmt.Sprint(*ptr)
+	}
+	panic(fmt.Sprintf("unsupported config field type %v", f.field.Type))
+}
+
+// set sets the value of field f in cfg to value.
+func (cfg *config) set(f configField, value string) error {
+	switch ptr := cfg.fieldPtr(f).(type) {
+	case *string:
+		if len(f.choices) > 0 {
+			// Verify that value is one of the allowed choices.
+			for _, choice := range f.choices {
+				if choice == value {
+					*ptr = value
+					return nil
+				}
+			}
+			return fmt.Errorf("invalid %q value %q", f.name, value)
+		}
+		*ptr = value
+	case *int:
+		v, err := strconv.Atoi(value)
+		if err != nil {
+			return err
+		}
+		*ptr = v
+	case *float64:
+		v, err := strconv.ParseFloat(value, 64)
+		if err != nil {
+			return err
+		}
+		*ptr = v
+	case *bool:
+		v, err := stringToBool(value)
+		if err != nil {
+			return err
+		}
+		*ptr = v
+	default:
+		panic(fmt.Sprintf("unsupported config field type %v", f.field.Type))
+	}
+	return nil
+}
+
+// isConfigurable returns true if name is either the name of a config field, or
+// a valid value for a multi-choice config field.
+func isConfigurable(name string) bool {
+	_, ok := configFieldMap[name]
+	return ok
+}
+
+// isBoolConfig returns true if name is either name of a boolean config field,
+// or a valid value for a multi-choice config field.
+func isBoolConfig(name string) bool {
+	f, ok := configFieldMap[name]
+	if !ok {
+		return false
+	}
+	if name != f.name {
+		return true // name must be one possible value for the field
+	}
+	var cfg config
+	_, ok = cfg.fieldPtr(f).(*bool)
+	return ok
+}
+
+// completeConfig returns the list of configurable names starting with prefix.
+func completeConfig(prefix string) []string {
+	var result []string
+	for v := range configFieldMap {
+		if strings.HasPrefix(v, prefix) {
+			result = append(result, v)
+		}
+	}
+	return result
+}
+
+// configure stores the name=value mapping into the current config, correctly
+// handling the case when name identifies a particular choice in a field.
+func configure(name, value string) error {
+	currentMu.Lock()
+	defer currentMu.Unlock()
+	f, ok := configFieldMap[name]
+	if !ok {
+		return fmt.Errorf("unknown config field %q", name)
+	}
+	if f.name == name {
+		return currentCfg.set(f, value)
+	}
+	// name must be one of the choices. If value is true, set field-value
+	// to name.
+	if v, err := strconv.ParseBool(value); v && err == nil {
+		return currentCfg.set(f, name)
+	}
+	return fmt.Errorf("unknown config field %q", name)
+}
+
+// resetTransient sets all transient fields in *cfg to their currently
+// configured values.
+func (cfg *config) resetTransient() {
+	current := currentConfig()
+	cfg.Output = current.Output
+	cfg.SourcePath = current.SourcePath
+	cfg.TrimPath = current.TrimPath
+	cfg.DivideBy = current.DivideBy
+	cfg.SampleIndex = current.SampleIndex
+}
+
+// applyURL updates *cfg based on params.
+func (cfg *config) applyURL(params url.Values) error {
+	for _, f := range configFields {
+		var value string
+		if f.urlparam != "" {
+			value = params.Get(f.urlparam)
+		}
+		if value == "" {
+			continue
+		}
+		if err := cfg.set(f, value); err != nil {
+			return fmt.Errorf("error setting config field %s: %v", f.name, err)
+		}
+	}
+	return nil
+}
+
+// makeURL returns a URL based on initialURL that contains the config contents
+// as parameters.  The second result is true iff a parameter value was changed.
+func (cfg *config) makeURL(initialURL url.URL) (url.URL, bool) {
+	q := initialURL.Query()
+	changed := false
+	for _, f := range configFields {
+		if f.urlparam == "" || !f.saved {
+			continue
+		}
+		v := cfg.get(f)
+		if v == f.defaultValue {
+			v = "" // URL for of default value is the empty string.
+		} else if f.field.Type.Kind() == reflect.Bool {
+			// Shorten bool values to "f" or "t"
+			v = v[:1]
+		}
+		if q.Get(f.urlparam) == v {
+			continue
+		}
+		changed = true
+		if v == "" {
+			q.Del(f.urlparam)
+		} else {
+			q.Set(f.urlparam, v)
+		}
+	}
+	if changed {
+		initialURL.RawQuery = q.Encode()
+	}
+	return initialURL, changed
+}

src/cmd/vendor/github.com/google/pprof/internal/driver/driver.go

@@ -50,7 +50,7 @@ func PProf(eo *plugin.Options) error {
 	}
 
 	if cmd != nil {
-		return generateReport(p, cmd, pprofVariables, o)
+		return generateReport(p, cmd, currentConfig(), o)
 	}
 
 	if src.HTTPHostport != "" {
@@ -59,7 +59,7 @@ func PProf(eo *plugin.Options) error {
 	return interactive(p, o)
 }
 
-func generateRawReport(p *profile.Profile, cmd []string, vars variables, o *plugin.Options) (*command, *report.Report, error) {
+func generateRawReport(p *profile.Profile, cmd []string, cfg config, o *plugin.Options) (*command, *report.Report, error) {
 	p = p.Copy() // Prevent modification to the incoming profile.
 
 	// Identify units of numeric tags in profile.
@@ -71,16 +71,16 @@ func generateRawReport(p *profile.Profile, cmd []string, vars variables, o *plug
 		panic("unexpected nil command")
 	}
 
-	vars = applyCommandOverrides(cmd[0], c.format, vars)
+	cfg = applyCommandOverrides(cmd[0], c.format, cfg)
 
 	// Delay focus after configuring report to get percentages on all samples.
-	relative := vars["relative_percentages"].boolValue()
+	relative := cfg.RelativePercentages
 	if relative {
-		if err := applyFocus(p, numLabelUnits, vars, o.UI); err != nil {
+		if err := applyFocus(p, numLabelUnits, cfg, o.UI); err != nil {
 			return nil, nil, err
 		}
 	}
-	ropt, err := reportOptions(p, numLabelUnits, vars)
+	ropt, err := reportOptions(p, numLabelUnits, cfg)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -95,19 +95,19 @@ func generateRawReport(p *profile.Profile, cmd []string, vars variables, o *plug
 
 	rpt := report.New(p, ropt)
 	if !relative {
-		if err := applyFocus(p, numLabelUnits, vars, o.UI); err != nil {
+		if err := applyFocus(p, numLabelUnits, cfg, o.UI); err != nil {
 			return nil, nil, err
 		}
 	}
-	if err := aggregate(p, vars); err != nil {
+	if err := aggregate(p, cfg); err != nil {
 		return nil, nil, err
 	}
 
 	return c, rpt, nil
 }
 
-func generateReport(p *profile.Profile, cmd []string, vars variables, o *plugin.Options) error {
+func generateReport(p *profile.Profile, cmd []string, cfg config, o *plugin.Options) error {
-	c, rpt, err := generateRawReport(p, cmd, vars, o)
+	c, rpt, err := generateRawReport(p, cmd, cfg, o)
 	if err != nil {
 		return err
 	}
@@ -129,7 +129,7 @@ func generateReport(p *profile.Profile, cmd []string, vars variables, o *plugin.
 	}
 
 	// If no output is specified, use default visualizer.
-	output := vars["output"].value
+	output := cfg.Output
 	if output == "" {
 		if c.visualizer != nil {
 			return c.visualizer(src, os.Stdout, o.UI)
@@ -151,7 +151,7 @@ func generateReport(p *profile.Profile, cmd []string, vars variables, o *plugin.
 	return out.Close()
 }
 
-func applyCommandOverrides(cmd string, outputFormat int, v variables) variables {
+func applyCommandOverrides(cmd string, outputFormat int, cfg config) config {
 	// Some report types override the trim flag to false below. This is to make
 	// sure the default heuristics of excluding insignificant nodes and edges
 	// from the call graph do not apply. One example where it is important is
@@ -160,55 +160,55 @@ func applyCommandOverrides(cmd string, outputFormat int, v variables) variables
 	// data is selected. So, with trimming enabled, the report could end up
 	// showing no data if the specified function is "uninteresting" as far as the
 	// trimming is concerned.
-	trim := v["trim"].boolValue()
+	trim := cfg.Trim
 
 	switch cmd {
 	case "disasm", "weblist":
 		trim = false
-		v.set("addresses", "t")
+		cfg.Granularity = "addresses"
 		// Force the 'noinlines' mode so that source locations for a given address
 		// collapse and there is only one for the given address. Without this
 		// cumulative metrics would be double-counted when annotating the assembly.
 		// This is because the merge is done by address and in case of an inlined
 		// stack each of the inlined entries is a separate callgraph node.
-		v.set("noinlines", "t")
+		cfg.NoInlines = true
 	case "peek":
 		trim = false
 	case "list":
 		trim = false
-		v.set("lines", "t")
+		cfg.Granularity = "lines"
 		// Do not force 'noinlines' to be false so that specifying
 		// "-list foo -noinlines" is supported and works as expected.
 	case "text", "top", "topproto":
-		if v["nodecount"].intValue() == -1 {
+		if cfg.NodeCount == -1 {
-			v.set("nodecount", "0")
+			cfg.NodeCount = 0
 		}
 	default:
-		if v["nodecount"].intValue() == -1 {
+		if cfg.NodeCount == -1 {
-			v.set("nodecount", "80")
+			cfg.NodeCount = 80
 		}
 	}
 
 	switch outputFormat {
 	case report.Proto, report.Raw, report.Callgrind:
 		trim = false
-		v.set("addresses", "t")
+		cfg.Granularity = "addresses"
-		v.set("noinlines", "f")
+		cfg.NoInlines = false
 	}
 
 	if !trim {
-		v.set("nodecount", "0")
+		cfg.NodeCount = 0
-		v.set("nodefraction", "0")
+		cfg.NodeFraction = 0
-		v.set("edgefraction", "0")
+		cfg.EdgeFraction = 0
 	}
-	return v
+	return cfg
 }
 
-func aggregate(prof *profile.Profile, v variables) error {
+func aggregate(prof *profile.Profile, cfg config) error {
 	var function, filename, linenumber, address bool
-	inlines := !v["noinlines"].boolValue()
+	inlines := !cfg.NoInlines
-	switch {
+	switch cfg.Granularity {
-	case v["addresses"].boolValue():
+	case "addresses":
 		if inlines {
 			return nil
 		}
@@ -216,15 +216,15 @@ func aggregate(prof *profile.Profile, v variables) error {
 		filename = true
 		linenumber = true
 		address = true
-	case v["lines"].boolValue():
+	case "lines":
 		function = true
 		filename = true
 		linenumber = true
-	case v["files"].boolValue():
+	case "files":
 		filename = true
-	case v["functions"].boolValue():
+	case "functions":
 		function = true
-	case v["filefunctions"].boolValue():
+	case "filefunctions":
 		function = true
 		filename = true
 	default:
@@ -233,8 +233,8 @@ func aggregate(prof *profile.Profile, v variables) error {
 	return prof.Aggregate(inlines, function, filename, linenumber, address)
 }
 
-func reportOptions(p *profile.Profile, numLabelUnits map[string]string, vars variables) (*report.Options, error) {
+func reportOptions(p *profile.Profile, numLabelUnits map[string]string, cfg config) (*report.Options, error) {
-	si, mean := vars["sample_index"].value, vars["mean"].boolValue()
+	si, mean := cfg.SampleIndex, cfg.Mean
 	value, meanDiv, sample, err := sampleFormat(p, si, mean)
 	if err != nil {
 		return nil, err
@@ -245,29 +245,37 @@ func reportOptions(p *profile.Profile, numLabelUnits map[string]string, vars var
 		stype = "mean_" + stype
 	}
 
-	if vars["divide_by"].floatValue() == 0 {
+	if cfg.DivideBy == 0 {
 		return nil, fmt.Errorf("zero divisor specified")
 	}
 
 	var filters []string
-	for _, k := range []string{"focus", "ignore", "hide", "show", "show_from", "tagfocus", "tagignore", "tagshow", "taghide"} {
+	addFilter := func(k string, v string) {
-		v := vars[k].value
 		if v != "" {
 			filters = append(filters, k+"="+v)
 		}
 	}
+	addFilter("focus", cfg.Focus)
+	addFilter("ignore", cfg.Ignore)
+	addFilter("hide", cfg.Hide)
+	addFilter("show", cfg.Show)
+	addFilter("show_from", cfg.ShowFrom)
+	addFilter("tagfocus", cfg.TagFocus)
+	addFilter("tagignore", cfg.TagIgnore)
+	addFilter("tagshow", cfg.TagShow)
+	addFilter("taghide", cfg.TagHide)
 
 	ropt := &report.Options{
-		CumSort:      vars["cum"].boolValue(),
+		CumSort:      cfg.Sort == "cum",
-		CallTree:     vars["call_tree"].boolValue(),
+		CallTree:     cfg.CallTree,
-		DropNegative: vars["drop_negative"].boolValue(),
+		DropNegative: cfg.DropNegative,
 
-		CompactLabels: vars["compact_labels"].boolValue(),
+		CompactLabels: cfg.CompactLabels,
-		Ratio:         1 / vars["divide_by"].floatValue(),
+		Ratio:         1 / cfg.DivideBy,
 
-		NodeCount:    vars["nodecount"].intValue(),
+		NodeCount:    cfg.NodeCount,
-		NodeFraction: vars["nodefraction"].floatValue(),
+		NodeFraction: cfg.NodeFraction,
-		EdgeFraction: vars["edgefraction"].floatValue(),
+		EdgeFraction: cfg.EdgeFraction,
 
 		ActiveFilters: filters,
 		NumLabelUnits: numLabelUnits,
@@ -277,10 +285,12 @@ func reportOptions(p *profile.Profile, numLabelUnits map[string]string, vars var
 		SampleType:        stype,
 		SampleUnit:        sample.Unit,
 
-		OutputUnit: vars["unit"].value,
+		OutputUnit: cfg.Unit,
 
-		SourcePath: vars["source_path"].stringValue(),
+		SourcePath: cfg.SourcePath,
-		TrimPath:   vars["trim_path"].stringValue(),
+		TrimPath:   cfg.TrimPath,
+
+		IntelSyntax: cfg.IntelSyntax,
 	}
 
 	if len(p.Mapping) > 0 && p.Mapping[0].File != "" {

src/cmd/vendor/github.com/google/pprof/internal/driver/driver_focus.go

@@ -28,15 +28,15 @@ import (
 var tagFilterRangeRx = regexp.MustCompile("([+-]?[[:digit:]]+)([[:alpha:]]+)?")
 
 // applyFocus filters samples based on the focus/ignore options
-func applyFocus(prof *profile.Profile, numLabelUnits map[string]string, v variables, ui plugin.UI) error {
+func applyFocus(prof *profile.Profile, numLabelUnits map[string]string, cfg config, ui plugin.UI) error {
-	focus, err := compileRegexOption("focus", v["focus"].value, nil)
+	focus, err := compileRegexOption("focus", cfg.Focus, nil)
-	ignore, err := compileRegexOption("ignore", v["ignore"].value, err)
+	ignore, err := compileRegexOption("ignore", cfg.Ignore, err)
-	hide, err := compileRegexOption("hide", v["hide"].value, err)
+	hide, err := compileRegexOption("hide", cfg.Hide, err)
-	show, err := compileRegexOption("show", v["show"].value, err)
+	show, err := compileRegexOption("show", cfg.Show, err)
-	showfrom, err := compileRegexOption("show_from", v["show_from"].value, err)
+	showfrom, err := compileRegexOption("show_from", cfg.ShowFrom, err)
-	tagfocus, err := compileTagFilter("tagfocus", v["tagfocus"].value, numLabelUnits, ui, err)
+	tagfocus, err := compileTagFilter("tagfocus", cfg.TagFocus, numLabelUnits, ui, err)
-	tagignore, err := compileTagFilter("tagignore", v["tagignore"].value, numLabelUnits, ui, err)
+	tagignore, err := compileTagFilter("tagignore", cfg.TagIgnore, numLabelUnits, ui, err)
-	prunefrom, err := compileRegexOption("prune_from", v["prune_from"].value, err)
+	prunefrom, err := compileRegexOption("prune_from", cfg.PruneFrom, err)
 	if err != nil {
 		return err
 	}
@@ -54,8 +54,8 @@ func applyFocus(prof *profile.Profile, numLabelUnits map[string]string, v variab
 	warnNoMatches(tagfocus == nil || tfm, "TagFocus", ui)
 	warnNoMatches(tagignore == nil || tim, "TagIgnore", ui)
 
-	tagshow, err := compileRegexOption("tagshow", v["tagshow"].value, err)
+	tagshow, err := compileRegexOption("tagshow", cfg.TagShow, err)
-	taghide, err := compileRegexOption("taghide", v["taghide"].value, err)
+	taghide, err := compileRegexOption("taghide", cfg.TagHide, err)
 	tns, tnh := prof.FilterTagsByName(tagshow, taghide)
 	warnNoMatches(tagshow == nil || tns, "TagShow", ui)
 	warnNoMatches(tagignore == nil || tnh, "TagHide", ui)

src/cmd/vendor/github.com/google/pprof/internal/driver/flamegraph.go

@@ -38,7 +38,10 @@ type treeNode struct {
 func (ui *webInterface) flamegraph(w http.ResponseWriter, req *http.Request) {
 	// Force the call tree so that the graph is a tree.
 	// Also do not trim the tree so that the flame graph contains all functions.
-	rpt, errList := ui.makeReport(w, req, []string{"svg"}, "call_tree", "true", "trim", "false")
+	rpt, errList := ui.makeReport(w, req, []string{"svg"}, func(cfg *config) {
+		cfg.CallTree = true
+		cfg.Trim = false
+	})
 	if rpt == nil {
 		return // error already reported
 	}
@@ -96,7 +99,7 @@ func (ui *webInterface) flamegraph(w http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	ui.render(w, "flamegraph", rpt, errList, config.Labels, webArgs{
+	ui.render(w, req, "flamegraph", rpt, errList, config.Labels, webArgs{
 		FlameGraph: template.JS(b),
 		Nodes:      nodeArr,
 	})

src/cmd/vendor/github.com/google/pprof/internal/driver/interactive.go

@@ -34,17 +34,14 @@ var tailDigitsRE = regexp.MustCompile("[0-9]+$")
 func interactive(p *profile.Profile, o *plugin.Options) error {
 	// Enter command processing loop.
 	o.UI.SetAutoComplete(newCompleter(functionNames(p)))
-	pprofVariables.set("compact_labels", "true")
+	configure("compact_labels", "true")
-	pprofVariables["sample_index"].help += fmt.Sprintf("Or use sample_index=name, with name in %v.\n", sampleTypes(p))
+	configHelp["sample_index"] += fmt.Sprintf("Or use sample_index=name, with name in %v.\n", sampleTypes(p))
 
 	// Do not wait for the visualizer to complete, to allow multiple
 	// graphs to be visualized simultaneously.
 	interactiveMode = true
 	shortcuts := profileShortcuts(p)
 
-	// Get all groups in pprofVariables to allow for clearer error messages.
-	groups := groupOptions(pprofVariables)
-
 	greetings(p, o.UI)
 	for {
 		input, err := o.UI.ReadLine("(pprof) ")
@@ -69,7 +66,12 @@ func interactive(p *profile.Profile, o *plugin.Options) error {
 					}
 					value = strings.TrimSpace(value)
 				}
-				if v := pprofVariables[name]; v != nil {
+				if isConfigurable(name) {
+					// All non-bool options require inputs
+					if len(s) == 1 && !isBoolConfig(name) {
+						o.UI.PrintErr(fmt.Errorf("please specify a value, e.g. %s=<val>", name))
+						continue
+					}
 					if name == "sample_index" {
 						// Error check sample_index=xxx to ensure xxx is a valid sample type.
 						index, err := p.SampleIndexByName(value)
@@ -77,23 +79,17 @@ func interactive(p *profile.Profile, o *plugin.Options) error {
 							o.UI.PrintErr(err)
 							continue
 						}
+						if index < 0 || index >= len(p.SampleType) {
+							o.UI.PrintErr(fmt.Errorf("invalid sample_index %q", value))
+							continue
+						}
 						value = p.SampleType[index].Type
 					}
-					if err := pprofVariables.set(name, value); err != nil {
+					if err := configure(name, value); err != nil {
 						o.UI.PrintErr(err)
 					}
 					continue
 				}
-				// Allow group=variable syntax by converting into variable="".
-				if v := pprofVariables[value]; v != nil && v.group == name {
-					if err := pprofVariables.set(value, ""); err != nil {
-						o.UI.PrintErr(err)
-					}
-					continue
-				} else if okValues := groups[name]; okValues != nil {
-					o.UI.PrintErr(fmt.Errorf("unrecognized value for %s: %q. Use one of %s", name, value, strings.Join(okValues, ", ")))
-					continue
-				}
 			}
 
 			tokens := strings.Fields(input)
@@ -105,16 +101,16 @@ func interactive(p *profile.Profile, o *plugin.Options) error {
 			case "o", "options":
 				printCurrentOptions(p, o.UI)
 				continue
-			case "exit", "quit":
+			case "exit", "quit", "q":
 				return nil
 			case "help":
 				commandHelp(strings.Join(tokens[1:], " "), o.UI)
 				continue
 			}
 
-			args, vars, err := parseCommandLine(tokens)
+			args, cfg, err := parseCommandLine(tokens)
 			if err == nil {
-				err = generateReportWrapper(p, args, vars, o)
+				err = generateReportWrapper(p, args, cfg, o)
 			}
 
 			if err != nil {
@@ -124,30 +120,13 @@ func interactive(p *profile.Profile, o *plugin.Options) error {
 	}
 }
 
-// groupOptions returns a map containing all non-empty groups
-// mapped to an array of the option names in that group in
-// sorted order.
-func groupOptions(vars variables) map[string][]string {
-	groups := make(map[string][]string)
-	for name, option := range vars {
-		group := option.group
-		if group != "" {
-			groups[group] = append(groups[group], name)
-		}
-	}
-	for _, names := range groups {
-		sort.Strings(names)
-	}
-	return groups
-}
-
 var generateReportWrapper = generateReport // For testing purposes.
 
 // greetings prints a brief welcome and some overall profile
 // information before accepting interactive commands.
 func greetings(p *profile.Profile, ui plugin.UI) {
 	numLabelUnits := identifyNumLabelUnits(p, ui)
-	ropt, err := reportOptions(p, numLabelUnits, pprofVariables)
+	ropt, err := reportOptions(p, numLabelUnits, currentConfig())
 	if err == nil {
 		rpt := report.New(p, ropt)
 		ui.Print(strings.Join(report.ProfileLabels(rpt), "\n"))
@@ -200,27 +179,16 @@ func sampleTypes(p *profile.Profile) []string {
 
 func printCurrentOptions(p *profile.Profile, ui plugin.UI) {
 	var args []string
-	type groupInfo struct {
+	current := currentConfig()
-		set    string
+	for _, f := range configFields {
-		values []string
+		n := f.name
-	}
+		v := current.get(f)
-	groups := make(map[string]*groupInfo)
-	for n, o := range pprofVariables {
-		v := o.stringValue()
 		comment := ""
-		if g := o.group; g != "" {
-			gi, ok := groups[g]
-			if !ok {
-				gi = &groupInfo{}
-				groups[g] = gi
-			}
-			if o.boolValue() {
-				gi.set = n
-			}
-			gi.values = append(gi.values, n)
-			continue
-		}
 		switch {
+		case len(f.choices) > 0:
+			values := append([]string{}, f.choices...)
+			sort.Strings(values)
+			comment = "[" + strings.Join(values, " | ") + "]"
 		case n == "sample_index":
 			st := sampleTypes(p)
 			if v == "" {
@@ -242,18 +210,13 @@ func printCurrentOptions(p *profile.Profile, ui plugin.UI) {
 		}
 		args = append(args, fmt.Sprintf("  %-25s = %-20s %s", n, v, comment))
 	}
-	for g, vars := range groups {
-		sort.Strings(vars.values)
-		comment := commentStart + " [" + strings.Join(vars.values, " | ") + "]"
-		args = append(args, fmt.Sprintf("  %-25s = %-20s %s", g, vars.set, comment))
-	}
 	sort.Strings(args)
 	ui.Print(strings.Join(args, "\n"))
 }
 
 // parseCommandLine parses a command and returns the pprof command to
-// execute and a set of variables for the report.
+// execute and the configuration to use for the report.
-func parseCommandLine(input []string) ([]string, variables, error) {
+func parseCommandLine(input []string) ([]string, config, error) {
 	cmd, args := input[:1], input[1:]
 	name := cmd[0]
 
@@ -267,25 +230,32 @@ func parseCommandLine(input []string) ([]string, variables, error) {
 		}
 	}
 	if c == nil {
-		return nil, nil, fmt.Errorf("unrecognized command: %q", name)
+		if _, ok := configHelp[name]; ok {
+			value := "<val>"
+			if len(args) > 0 {
+				value = args[0]
+			}
+			return nil, config{}, fmt.Errorf("did you mean: %s=%s", name, value)
+		}
+		return nil, config{}, fmt.Errorf("unrecognized command: %q", name)
 	}
 
 	if c.hasParam {
 		if len(args) == 0 {
-			return nil, nil, fmt.Errorf("command %s requires an argument", name)
+			return nil, config{}, fmt.Errorf("command %s requires an argument", name)
 		}
 		cmd = append(cmd, args[0])
 		args = args[1:]
 	}
 
-	// Copy the variables as options set in the command line are not persistent.
+	// Copy config since options set in the command line should not persist.
-	vcopy := pprofVariables.makeCopy()
+	vcopy := currentConfig()
 
 	var focus, ignore string
 	for i := 0; i < len(args); i++ {
 		t := args[i]
-		if _, err := strconv.ParseInt(t, 10, 32); err == nil {
+		if n, err := strconv.ParseInt(t, 10, 32); err == nil {
-			vcopy.set("nodecount", t)
+			vcopy.NodeCount = int(n)
 			continue
 		}
 		switch t[0] {
@@ -294,14 +264,14 @@ func parseCommandLine(input []string) ([]string, variables, error) {
 			if outputFile == "" {
 				i++
 				if i >= len(args) {
-					return nil, nil, fmt.Errorf("unexpected end of line after >")
+					return nil, config{}, fmt.Errorf("unexpected end of line after >")
 				}
 				outputFile = args[i]
 			}
-			vcopy.set("output", outputFile)
+			vcopy.Output = outputFile
 		case '-':
 			if t == "--cum" || t == "-cum" {
-				vcopy.set("cum", "t")
+				vcopy.Sort = "cum"
 				continue
 			}
 			ignore = catRegex(ignore, t[1:])
@@ -311,30 +281,27 @@ func parseCommandLine(input []string) ([]string, variables, error) {
 	}
 
 	if name == "tags" {
-		updateFocusIgnore(vcopy, "tag", focus, ignore)
+		if focus != "" {
+			vcopy.TagFocus = focus
+		}
+		if ignore != "" {
+			vcopy.TagIgnore = ignore
+		}
 	} else {
-		updateFocusIgnore(vcopy, "", focus, ignore)
+		if focus != "" {
+			vcopy.Focus = focus
+		}
+		if ignore != "" {
+			vcopy.Ignore = ignore
+		}
 	}
-
+	if vcopy.NodeCount == -1 && (name == "text" || name == "top") {
-	if vcopy["nodecount"].intValue() == -1 && (name == "text" || name == "top") {
+		vcopy.NodeCount = 10
-		vcopy.set("nodecount", "10")
 	}
 
 	return cmd, vcopy, nil
 }
 
-func updateFocusIgnore(v variables, prefix, f, i string) {
-	if f != "" {
-		focus := prefix + "focus"
-		v.set(focus, catRegex(v[focus].value, f))
-	}
-
-	if i != "" {
-		ignore := prefix + "ignore"
-		v.set(ignore, catRegex(v[ignore].value, i))
-	}
-}
-
 func catRegex(a, b string) string {
 	if a != "" && b != "" {
 		return a + "|" + b
@@ -362,8 +329,8 @@ func commandHelp(args string, ui plugin.UI) {
 		return
 	}
 
-	if v := pprofVariables[args]; v != nil {
+	if help, ok := configHelp[args]; ok {
-		ui.Print(v.help + "\n")
+		ui.Print(help + "\n")
 		return
 	}
 
@@ -373,18 +340,17 @@ func commandHelp(args string, ui plugin.UI) {
 // newCompleter creates an autocompletion function for a set of commands.
 func newCompleter(fns []string) func(string) string {
 	return func(line string) string {
-		v := pprofVariables
 		switch tokens := strings.Fields(line); len(tokens) {
 		case 0:
 			// Nothing to complete
 		case 1:
 			// Single token -- complete command name
-			if match := matchVariableOrCommand(v, tokens[0]); match != "" {
+			if match := matchVariableOrCommand(tokens[0]); match != "" {
 				return match
 			}
 		case 2:
 			if tokens[0] == "help" {
-				if match := matchVariableOrCommand(v, tokens[1]); match != "" {
+				if match := matchVariableOrCommand(tokens[1]); match != "" {
 					return tokens[0] + " " + match
 				}
 				return line
@@ -408,26 +374,19 @@ func newCompleter(fns []string) func(string) string {
 }
 
 // matchVariableOrCommand attempts to match a string token to the prefix of a Command.
-func matchVariableOrCommand(v variables, token string) string {
+func matchVariableOrCommand(token string) string {
 	token = strings.ToLower(token)
-	found := ""
+	var matches []string
 	for cmd := range pprofCommands {
 		if strings.HasPrefix(cmd, token) {
-			if found != "" {
+			matches = append(matches, cmd)
-				return ""
-			}
-			found = cmd
 		}
 	}
-	for variable := range v {
+	matches = append(matches, completeConfig(token)...)
-		if strings.HasPrefix(variable, token) {
+	if len(matches) == 1 {
-			if found != "" {
+		return matches[0]
-				return ""
-			}
-			found = variable
-		}
 	}
-	return found
+	return ""
 }
 
 // functionCompleter replaces provided substring with a function

src/cmd/vendor/github.com/google/pprof/internal/driver/settings.go

@@ -0,0 +1,157 @@
+package driver
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/url"
+	"os"
+	"path/filepath"
+)
+
+// settings holds pprof settings.
+type settings struct {
+	// Configs holds a list of named UI configurations.
+	Configs []namedConfig `json:"configs"`
+}
+
+// namedConfig associates a name with a config.
+type namedConfig struct {
+	Name string `json:"name"`
+	config
+}
+
+// settingsFileName returns the name of the file where settings should be saved.
+func settingsFileName() (string, error) {
+	// Return "pprof/settings.json" under os.UserConfigDir().
+	dir, err := os.UserConfigDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(dir, "pprof", "settings.json"), nil
+}
+
+// readSettings reads settings from fname.
+func readSettings(fname string) (*settings, error) {
+	data, err := ioutil.ReadFile(fname)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return &settings{}, nil
+		}
+		return nil, fmt.Errorf("could not read settings: %w", err)
+	}
+	settings := &settings{}
+	if err := json.Unmarshal(data, settings); err != nil {
+		return nil, fmt.Errorf("could not parse settings: %w", err)
+	}
+	for i := range settings.Configs {
+		settings.Configs[i].resetTransient()
+	}
+	return settings, nil
+}
+
+// writeSettings saves settings to fname.
+func writeSettings(fname string, settings *settings) error {
+	data, err := json.MarshalIndent(settings, "", "  ")
+	if err != nil {
+		return fmt.Errorf("could not encode settings: %w", err)
+	}
+
+	// create the settings directory if it does not exist
+	// XDG specifies permissions 0700 when creating settings dirs:
+	// https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
+	if err := os.MkdirAll(filepath.Dir(fname), 0700); err != nil {
+		return fmt.Errorf("failed to create settings directory: %w", err)
+	}
+
+	if err := ioutil.WriteFile(fname, data, 0644); err != nil {
+		return fmt.Errorf("failed to write settings: %w", err)
+	}
+	return nil
+}
+
+// configMenuEntry holds information for a single config menu entry.
+type configMenuEntry struct {
+	Name       string
+	URL        string
+	Current    bool // Is this the currently selected config?
+	UserConfig bool // Is this a user-provided config?
+}
+
+// configMenu returns a list of items to add to a menu in the web UI.
+func configMenu(fname string, url url.URL) []configMenuEntry {
+	// Start with system configs.
+	configs := []namedConfig{{Name: "Default", config: defaultConfig()}}
+	if settings, err := readSettings(fname); err == nil {
+		// Add user configs.
+		configs = append(configs, settings.Configs...)
+	}
+
+	// Convert to menu entries.
+	result := make([]configMenuEntry, len(configs))
+	lastMatch := -1
+	for i, cfg := range configs {
+		dst, changed := cfg.config.makeURL(url)
+		if !changed {
+			lastMatch = i
+		}
+		result[i] = configMenuEntry{
+			Name:       cfg.Name,
+			URL:        dst.String(),
+			UserConfig: (i != 0),
+		}
+	}
+	// Mark the last matching config as currennt
+	if lastMatch >= 0 {
+		result[lastMatch].Current = true
+	}
+	return result
+}
+
+// editSettings edits settings by applying fn to them.
+func editSettings(fname string, fn func(s *settings) error) error {
+	settings, err := readSettings(fname)
+	if err != nil {
+		return err
+	}
+	if err := fn(settings); err != nil {
+		return err
+	}
+	return writeSettings(fname, settings)
+}
+
+// setConfig saves the config specified in request to fname.
+func setConfig(fname string, request url.URL) error {
+	q := request.Query()
+	name := q.Get("config")
+	if name == "" {
+		return fmt.Errorf("invalid config name")
+	}
+	cfg := currentConfig()
+	if err := cfg.applyURL(q); err != nil {
+		return err
+	}
+	return editSettings(fname, func(s *settings) error {
+		for i, c := range s.Configs {
+			if c.Name == name {
+				s.Configs[i].config = cfg
+				return nil
+			}
+		}
+		s.Configs = append(s.Configs, namedConfig{Name: name, config: cfg})
+		return nil
+	})
+}
+
+// removeConfig removes config from fname.
+func removeConfig(fname, config string) error {
+	return editSettings(fname, func(s *settings) error {
+		for i, c := range s.Configs {
+			if c.Name == config {
+				s.Configs = append(s.Configs[:i], s.Configs[i+1:]...)
+				return nil
+			}
+		}
+		return fmt.Errorf("config %s not found", config)
+	})
+}

src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go

@@ -166,6 +166,73 @@ a {
   color: gray;
   pointer-events: none;
 }
+.menu-check-mark {
+  position: absolute;
+  left: 2px;
+}
+.menu-delete-btn {
+  position: absolute;
+  right: 2px;
+}
+
+{{/* Used to disable events when a modal dialog is displayed */}}
+#dialog-overlay {
+  display: none;
+  position: fixed;
+  left: 0px;
+  top: 0px;
+  width: 100%;
+  height: 100%;
+  background-color: rgba(1,1,1,0.1);
+}
+
+.dialog {
+  {{/* Displayed centered horizontally near the top */}}
+  display: none;
+  position: fixed;
+  margin: 0px;
+  top: 60px;
+  left: 50%;
+  transform: translateX(-50%);
+
+  z-index: 3;
+  font-size: 125%;
+  background-color: #ffffff;
+  box-shadow: 0 1px 5px rgba(0,0,0,.3);
+}
+.dialog-header {
+  font-size: 120%;
+  border-bottom: 1px solid #CCCCCC;
+  width: 100%;
+  text-align: center;
+  background: #EEEEEE;
+  user-select: none;
+}
+.dialog-footer {
+  border-top: 1px solid #CCCCCC;
+  width: 100%;
+  text-align: right;
+  padding: 10px;
+}
+.dialog-error {
+  margin: 10px;
+  color: red;
+}
+.dialog input {
+  margin: 10px;
+  font-size: inherit;
+}
+.dialog button {
+  margin-left: 10px;
+  font-size: inherit;
+}
+#save-dialog, #delete-dialog {
+  width: 50%;
+  max-width: 20em;
+}
+#delete-prompt {
+  padding: 10px;
+}
 
 #content {
   overflow-y: scroll;
@@ -200,6 +267,8 @@ table thead {
   font-family: 'Roboto Medium', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
 }
 table tr th {
+  position: sticky;
+  top: 0;
   background-color: #ddd;
   text-align: right;
   padding: .3em .5em;
@@ -282,6 +351,24 @@ table tr td {
     </div>
   </div>
 
+  <div id="config" class="menu-item">
+    <div class="menu-name">
+      Config
+      <i class="downArrow"></i>
+    </div>
+    <div class="submenu">
+      <a title="{{.Help.save_config}}" id="save-config">Save as ...</a>
+      <hr>
+      {{range .Configs}}
+        <a href="{{.URL}}">
+          {{if .Current}}<span class="menu-check-mark">✓</span>{{end}}
+          {{.Name}}
+          {{if .UserConfig}}<span class="menu-delete-btn" data-config={{.Name}}>🗙</span>{{end}}
+        </a>
+      {{end}}
+    </div>
+  </div>
+
   <div>
     <input id="search" type="text" placeholder="Search regexp" autocomplete="off" autocapitalize="none" size=40>
   </div>
@@ -294,6 +381,31 @@ table tr td {
   </div>
 </div>
 
+<div id="dialog-overlay"></div>
+
+<div class="dialog" id="save-dialog">
+  <div class="dialog-header">Save options as</div>
+  <datalist id="config-list">
+    {{range .Configs}}{{if .UserConfig}}<option value="{{.Name}}" />{{end}}{{end}}
+  </datalist>
+  <input id="save-name" type="text" list="config-list" placeholder="New config" />
+  <div class="dialog-footer">
+    <span class="dialog-error" id="save-error"></span>
+    <button id="save-cancel">Cancel</button>
+    <button id="save-confirm">Save</button>
+  </div>
+</div>
+
+<div class="dialog" id="delete-dialog">
+  <div class="dialog-header" id="delete-dialog-title">Delete config</div>
+  <div id="delete-prompt"></div>
+  <div class="dialog-footer">
+    <span class="dialog-error" id="delete-error"></span>
+    <button id="delete-cancel">Cancel</button>
+    <button id="delete-confirm">Delete</button>
+  </div>
+</div>
+
 <div id="errors">{{range .Errors}}<div>{{.}}</div>{{end}}</div>
 {{end}}
 
@@ -583,6 +695,131 @@ function initMenus() {
   }, { passive: true, capture: true });
 }
 
+function sendURL(method, url, done) {
+  fetch(url.toString(), {method: method})
+      .then((response) => { done(response.ok); })
+      .catch((error) => { done(false); });
+}
+
+// Initialize handlers for saving/loading configurations.
+function initConfigManager() {
+  'use strict';
+
+  // Initialize various elements.
+  function elem(id) {
+    const result = document.getElementById(id);
+    if (!result) console.warn('element ' + id + ' not found');
+    return result;
+  }
+  const overlay = elem('dialog-overlay');
+  const saveDialog = elem('save-dialog');
+  const saveInput = elem('save-name');
+  const saveError = elem('save-error');
+  const delDialog = elem('delete-dialog');
+  const delPrompt = elem('delete-prompt');
+  const delError = elem('delete-error');
+
+  let currentDialog = null;
+  let currentDeleteTarget = null;
+
+  function showDialog(dialog) {
+    if (currentDialog != null) {
+      overlay.style.display = 'none';
+      currentDialog.style.display = 'none';
+    }
+    currentDialog = dialog;
+    if (dialog != null) {
+      overlay.style.display = 'block';
+      dialog.style.display = 'block';
+    }
+  }
+
+  function cancelDialog(e) {
+    showDialog(null);
+  }
+
+  // Show dialog for saving the current config.
+  function showSaveDialog(e) {
+    saveError.innerText = '';
+    showDialog(saveDialog);
+    saveInput.focus();
+  }
+
+  // Commit save config.
+  function commitSave(e) {
+    const name = saveInput.value;
+    const url = new URL(document.URL);
+    // Set path relative to existing path.
+    url.pathname = new URL('./saveconfig', document.URL).pathname;
+    url.searchParams.set('config', name);
+    saveError.innerText = '';
+    sendURL('POST', url, (ok) => {
+      if (!ok) {
+        saveError.innerText = 'Save failed';
+      } else {
+        showDialog(null);
+        location.reload();  // Reload to show updated config menu
+      }
+    });
+  }
+
+  function handleSaveInputKey(e) {
+    if (e.key === 'Enter') commitSave(e);
+  }
+
+  function deleteConfig(e, elem) {
+    e.preventDefault();
+    const config = elem.dataset.config;
+    delPrompt.innerText = 'Delete ' + config + '?';
+    currentDeleteTarget = elem;
+    showDialog(delDialog);
+  }
+
+  function commitDelete(e, elem) {
+    if (!currentDeleteTarget) return;
+    const config = currentDeleteTarget.dataset.config;
+    const url = new URL('./deleteconfig', document.URL);
+    url.searchParams.set('config', config);
+    delError.innerText = '';
+    sendURL('DELETE', url, (ok) => {
+      if (!ok) {
+        delError.innerText = 'Delete failed';
+        return;
+      }
+      showDialog(null);
+      // Remove menu entry for this config.
+      if (currentDeleteTarget && currentDeleteTarget.parentElement) {
+        currentDeleteTarget.parentElement.remove();
+      }
+    });
+  }
+
+  // Bind event on elem to fn.
+  function bind(event, elem, fn) {
+    if (elem == null) return;
+    elem.addEventListener(event, fn);
+    if (event == 'click') {
+      // Also enable via touch.
+      elem.addEventListener('touchstart', fn);
+    }
+  }
+
+  bind('click', elem('save-config'), showSaveDialog);
+  bind('click', elem('save-cancel'), cancelDialog);
+  bind('click', elem('save-confirm'), commitSave);
+  bind('keydown', saveInput, handleSaveInputKey);
+
+  bind('click', elem('delete-cancel'), cancelDialog);
+  bind('click', elem('delete-confirm'), commitDelete);
+
+  // Activate deletion button for all config entries in menu.
+  for (const del of Array.from(document.getElementsByClassName('menu-delete-btn'))) {
+    bind('click', del, (e) => {
+      deleteConfig(e, del);
+    });
+  }
+}
+
 function viewer(baseUrl, nodes) {
   'use strict';
 
@@ -875,6 +1112,7 @@ function viewer(baseUrl, nodes) {
   }
 
   addAction('details', handleDetails);
+  initConfigManager();
 
   search.addEventListener('input', handleSearch);
   search.addEventListener('keydown', handleKey);

src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go

@@ -35,22 +35,28 @@ import (
 
 // webInterface holds the state needed for serving a browser based interface.
 type webInterface struct {
-	prof      *profile.Profile
+	prof         *profile.Profile
-	options   *plugin.Options
+	options      *plugin.Options
-	help      map[string]string
+	help         map[string]string
-	templates *template.Template
+	templates    *template.Template
+	settingsFile string
 }
 
-func makeWebInterface(p *profile.Profile, opt *plugin.Options) *webInterface {
+func makeWebInterface(p *profile.Profile, opt *plugin.Options) (*webInterface, error) {
+	settingsFile, err := settingsFileName()
+	if err != nil {
+		return nil, err
+	}
 	templates := template.New("templategroup")
 	addTemplates(templates)
 	report.AddSourceTemplates(templates)
 	return &webInterface{
-		prof:      p,
+		prof:         p,
-		options:   opt,
+		options:      opt,
-		help:      make(map[string]string),
+		help:         make(map[string]string),
-		templates: templates,
+		templates:    templates,
-	}
+		settingsFile: settingsFile,
+	}, nil
 }
 
 // maxEntries is the maximum number of entries to print for text interfaces.
@@ -80,6 +86,7 @@ type webArgs struct {
 	TextBody    string
 	Top         []report.TextItem
 	FlameGraph  template.JS
+	Configs     []configMenuEntry
 }
 
 func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options, disableBrowser bool) error {
@@ -88,16 +95,20 @@ func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options, d
 		return err
 	}
 	interactiveMode = true
-	ui := makeWebInterface(p, o)
+	ui, err := makeWebInterface(p, o)
+	if err != nil {
+		return err
+	}
 	for n, c := range pprofCommands {
 		ui.help[n] = c.description
 	}
-	for n, v := range pprofVariables {
+	for n, help := range configHelp {
-		ui.help[n] = v.help
+		ui.help[n] = help
 	}
 	ui.help["details"] = "Show information about the profile and this view"
 	ui.help["graph"] = "Display profile as a directed graph"
 	ui.help["reset"] = "Show the entire profile"
+	ui.help["save_config"] = "Save current settings"
 
 	server := o.HTTPServer
 	if server == nil {
@@ -108,12 +119,14 @@ func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options, d
 		Host:     host,
 		Port:     port,
 		Handlers: map[string]http.Handler{
-			"/":           http.HandlerFunc(ui.dot),
+			"/":             http.HandlerFunc(ui.dot),
-			"/top":        http.HandlerFunc(ui.top),
+			"/top":          http.HandlerFunc(ui.top),
-			"/disasm":     http.HandlerFunc(ui.disasm),
+			"/disasm":       http.HandlerFunc(ui.disasm),
-			"/source":     http.HandlerFunc(ui.source),
+			"/source":       http.HandlerFunc(ui.source),
-			"/peek":       http.HandlerFunc(ui.peek),
+			"/peek":         http.HandlerFunc(ui.peek),
-			"/flamegraph": http.HandlerFunc(ui.flamegraph),
+			"/flamegraph":   http.HandlerFunc(ui.flamegraph),
+			"/saveconfig":   http.HandlerFunc(ui.saveConfig),
+			"/deleteconfig": http.HandlerFunc(ui.deleteConfig),
 		},
 	}
 
@@ -206,21 +219,9 @@ func isLocalhost(host string) bool {
 
 func openBrowser(url string, o *plugin.Options) {
 	// Construct URL.
-	u, _ := gourl.Parse(url)
+	baseURL, _ := gourl.Parse(url)
-	q := u.Query()
+	current := currentConfig()
-	for _, p := range []struct{ param, key string }{
+	u, _ := current.makeURL(*baseURL)
-		{"f", "focus"},
-		{"s", "show"},
-		{"sf", "show_from"},
-		{"i", "ignore"},
-		{"h", "hide"},
-		{"si", "sample_index"},
-	} {
-		if v := pprofVariables[p.key].value; v != "" {
-			q.Set(p.param, v)
-		}
-	}
-	u.RawQuery = q.Encode()
 
 	// Give server a little time to get ready.
 	time.Sleep(time.Millisecond * 500)
@@ -240,28 +241,23 @@ func openBrowser(url string, o *plugin.Options) {
 	o.UI.PrintErr(u.String())
 }
 
-func varsFromURL(u *gourl.URL) variables {
-	vars := pprofVariables.makeCopy()
-	vars["focus"].value = u.Query().Get("f")
-	vars["show"].value = u.Query().Get("s")
-	vars["show_from"].value = u.Query().Get("sf")
-	vars["ignore"].value = u.Query().Get("i")
-	vars["hide"].value = u.Query().Get("h")
-	vars["sample_index"].value = u.Query().Get("si")
-	return vars
-}
-
 // makeReport generates a report for the specified command.
+// If configEditor is not null, it is used to edit the config used for the report.
 func (ui *webInterface) makeReport(w http.ResponseWriter, req *http.Request,
-	cmd []string, vars ...string) (*report.Report, []string) {
+	cmd []string, configEditor func(*config)) (*report.Report, []string) {
-	v := varsFromURL(req.URL)
+	cfg := currentConfig()
-	for i := 0; i+1 < len(vars); i += 2 {
+	if err := cfg.applyURL(req.URL.Query()); err != nil {
-		v[vars[i]].value = vars[i+1]
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		ui.options.UI.PrintErr(err)
+		return nil, nil
+	}
+	if configEditor != nil {
+		configEditor(&cfg)
 	}
 	catcher := &errorCatcher{UI: ui.options.UI}
 	options := *ui.options
 	options.UI = catcher
-	_, rpt, err := generateRawReport(ui.prof, cmd, v, &options)
+	_, rpt, err := generateRawReport(ui.prof, cmd, cfg, &options)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusBadRequest)
 		ui.options.UI.PrintErr(err)
@@ -271,7 +267,7 @@ func (ui *webInterface) makeReport(w http.ResponseWriter, req *http.Request,
 }
 
 // render generates html using the named template based on the contents of data.
-func (ui *webInterface) render(w http.ResponseWriter, tmpl string,
+func (ui *webInterface) render(w http.ResponseWriter, req *http.Request, tmpl string,
 	rpt *report.Report, errList, legend []string, data webArgs) {
 	file := getFromLegend(legend, "File: ", "unknown")
 	profile := getFromLegend(legend, "Type: ", "unknown")
@@ -281,6 +277,8 @@ func (ui *webInterface) render(w http.ResponseWriter, tmpl string,
 	data.SampleTypes = sampleTypes(ui.prof)
 	data.Legend = legend
 	data.Help = ui.help
+	data.Configs = configMenu(ui.settingsFile, *req.URL)
+
 	html := &bytes.Buffer{}
 	if err := ui.templates.ExecuteTemplate(html, tmpl, data); err != nil {
 		http.Error(w, "internal template error", http.StatusInternalServerError)
@@ -293,7 +291,7 @@ func (ui *webInterface) render(w http.ResponseWriter, tmpl string,
 
 // dot generates a web page containing an svg diagram.
 func (ui *webInterface) dot(w http.ResponseWriter, req *http.Request) {
-	rpt, errList := ui.makeReport(w, req, []string{"svg"})
+	rpt, errList := ui.makeReport(w, req, []string{"svg"}, nil)
 	if rpt == nil {
 		return // error already reported
 	}
@@ -320,7 +318,7 @@ func (ui *webInterface) dot(w http.ResponseWriter, req *http.Request) {
 		nodes = append(nodes, n.Info.Name)
 	}
 
-	ui.render(w, "graph", rpt, errList, legend, webArgs{
+	ui.render(w, req, "graph", rpt, errList, legend, webArgs{
 		HTMLBody: template.HTML(string(svg)),
 		Nodes:    nodes,
 	})
@@ -345,7 +343,9 @@ func dotToSvg(dot []byte) ([]byte, error) {
 }
 
 func (ui *webInterface) top(w http.ResponseWriter, req *http.Request) {
-	rpt, errList := ui.makeReport(w, req, []string{"top"}, "nodecount", "500")
+	rpt, errList := ui.makeReport(w, req, []string{"top"}, func(cfg *config) {
+		cfg.NodeCount = 500
+	})
 	if rpt == nil {
 		return // error already reported
 	}
@@ -355,7 +355,7 @@ func (ui *webInterface) top(w http.ResponseWriter, req *http.Request) {
 		nodes = append(nodes, item.Name)
 	}
 
-	ui.render(w, "top", rpt, errList, legend, webArgs{
+	ui.render(w, req, "top", rpt, errList, legend, webArgs{
 		Top:   top,
 		Nodes: nodes,
 	})
@@ -364,7 +364,7 @@ func (ui *webInterface) top(w http.ResponseWriter, req *http.Request) {
 // disasm generates a web page containing disassembly.
 func (ui *webInterface) disasm(w http.ResponseWriter, req *http.Request) {
 	args := []string{"disasm", req.URL.Query().Get("f")}
-	rpt, errList := ui.makeReport(w, req, args)
+	rpt, errList := ui.makeReport(w, req, args, nil)
 	if rpt == nil {
 		return // error already reported
 	}
@@ -377,7 +377,7 @@ func (ui *webInterface) disasm(w http.ResponseWriter, req *http.Request) {
 	}
 
 	legend := report.ProfileLabels(rpt)
-	ui.render(w, "plaintext", rpt, errList, legend, webArgs{
+	ui.render(w, req, "plaintext", rpt, errList, legend, webArgs{
 		TextBody: out.String(),
 	})
 
@@ -387,7 +387,7 @@ func (ui *webInterface) disasm(w http.ResponseWriter, req *http.Request) {
 // data.
 func (ui *webInterface) source(w http.ResponseWriter, req *http.Request) {
 	args := []string{"weblist", req.URL.Query().Get("f")}
-	rpt, errList := ui.makeReport(w, req, args)
+	rpt, errList := ui.makeReport(w, req, args, nil)
 	if rpt == nil {
 		return // error already reported
 	}
@@ -401,7 +401,7 @@ func (ui *webInterface) source(w http.ResponseWriter, req *http.Request) {
 	}
 
 	legend := report.ProfileLabels(rpt)
-	ui.render(w, "sourcelisting", rpt, errList, legend, webArgs{
+	ui.render(w, req, "sourcelisting", rpt, errList, legend, webArgs{
 		HTMLBody: template.HTML(body.String()),
 	})
 }
@@ -409,7 +409,9 @@ func (ui *webInterface) source(w http.ResponseWriter, req *http.Request) {
 // peek generates a web page listing callers/callers.
 func (ui *webInterface) peek(w http.ResponseWriter, req *http.Request) {
 	args := []string{"peek", req.URL.Query().Get("f")}
-	rpt, errList := ui.makeReport(w, req, args, "lines", "t")
+	rpt, errList := ui.makeReport(w, req, args, func(cfg *config) {
+		cfg.Granularity = "lines"
+	})
 	if rpt == nil {
 		return // error already reported
 	}
@@ -422,11 +424,30 @@ func (ui *webInterface) peek(w http.ResponseWriter, req *http.Request) {
 	}
 
 	legend := report.ProfileLabels(rpt)
-	ui.render(w, "plaintext", rpt, errList, legend, webArgs{
+	ui.render(w, req, "plaintext", rpt, errList, legend, webArgs{
 		TextBody: out.String(),
 	})
 }
 
+// saveConfig saves URL configuration.
+func (ui *webInterface) saveConfig(w http.ResponseWriter, req *http.Request) {
+	if err := setConfig(ui.settingsFile, *req.URL); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		ui.options.UI.PrintErr(err)
+		return
+	}
+}
+
+// deleteConfig deletes a configuration.
+func (ui *webInterface) deleteConfig(w http.ResponseWriter, req *http.Request) {
+	name := req.URL.Query().Get("config")
+	if err := removeConfig(ui.settingsFile, name); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		ui.options.UI.PrintErr(err)
+		return
+	}
+}
+
 // getFromLegend returns the suffix of an entry in legend that starts
 // with param.  It returns def if no such entry is found.
 func getFromLegend(legend []string, param, def string) string {

src/cmd/vendor/github.com/google/pprof/internal/plugin/plugin.go

@@ -114,7 +114,7 @@ type ObjTool interface {
 
 	// Disasm disassembles the named object file, starting at
 	// the start address and stopping at (before) the end address.
-	Disasm(file string, start, end uint64) ([]Inst, error)
+	Disasm(file string, start, end uint64, intelSyntax bool) ([]Inst, error)
 }
 
 // An Inst is a single instruction in an assembly listing.

src/cmd/vendor/github.com/google/pprof/internal/report/report.go

@@ -79,6 +79,8 @@ type Options struct {
 	Symbol     *regexp.Regexp // Symbols to include on disassembly report.
 	SourcePath string         // Search path for source files.
 	TrimPath   string         // Paths to trim from source file paths.
+
+	IntelSyntax bool // Whether or not to print assembly in Intel syntax.
 }
 
 // Generate generates a report as directed by the Report.
@@ -438,7 +440,7 @@ func PrintAssembly(w io.Writer, rpt *Report, obj plugin.ObjTool, maxFuncs int) e
 		flatSum, cumSum := sns.Sum()
 
 		// Get the function assembly.
-		insts, err := obj.Disasm(s.sym.File, s.sym.Start, s.sym.End)
+		insts, err := obj.Disasm(s.sym.File, s.sym.Start, s.sym.End, o.IntelSyntax)
 		if err != nil {
 			return err
 		}
@@ -1201,6 +1203,13 @@ func reportLabels(rpt *Report, g *graph.Graph, origCount, droppedNodes, droppedE
 				nodeCount, origCount))
 		}
 	}
+
+	// Help new users understand the graph.
+	// A new line is intentionally added here to better show this message.
+	if fullHeaders {
+		label = append(label, "\\lSee https://git.io/JfYMW for how to read the graph")
+	}
+
 	return label
 }
 

src/cmd/vendor/github.com/google/pprof/internal/report/source.go

@@ -205,7 +205,7 @@ func PrintWebList(w io.Writer, rpt *Report, obj plugin.ObjTool, maxFiles int) er
 		ff := fileFunction{n.Info.File, n.Info.Name}
 		fns := fileNodes[ff]
 
-		asm := assemblyPerSourceLine(symbols, fns, ff.fileName, obj)
+		asm := assemblyPerSourceLine(symbols, fns, ff.fileName, obj, o.IntelSyntax)
 		start, end := sourceCoordinates(asm)
 
 		fnodes, path, err := getSourceFromFile(ff.fileName, reader, fns, start, end)
@@ -239,7 +239,7 @@ func sourceCoordinates(asm map[int][]assemblyInstruction) (start, end int) {
 // assemblyPerSourceLine disassembles the binary containing a symbol
 // and classifies the assembly instructions according to its
 // corresponding source line, annotating them with a set of samples.
-func assemblyPerSourceLine(objSyms []*objSymbol, rs graph.Nodes, src string, obj plugin.ObjTool) map[int][]assemblyInstruction {
+func assemblyPerSourceLine(objSyms []*objSymbol, rs graph.Nodes, src string, obj plugin.ObjTool, intelSyntax bool) map[int][]assemblyInstruction {
 	assembly := make(map[int][]assemblyInstruction)
 	// Identify symbol to use for this collection of samples.
 	o := findMatchingSymbol(objSyms, rs)
@@ -248,7 +248,7 @@ func assemblyPerSourceLine(objSyms []*objSymbol, rs graph.Nodes, src string, obj
 	}
 
 	// Extract assembly for matched symbol
-	insts, err := obj.Disasm(o.sym.File, o.sym.Start, o.sym.End)
+	insts, err := obj.Disasm(o.sym.File, o.sym.Start, o.sym.End, intelSyntax)
 	if err != nil {
 		return assembly
 	}

src/cmd/vendor/github.com/google/pprof/profile/profile.go

@@ -398,10 +398,12 @@ func (p *Profile) CheckValid() error {
 			}
 		}
 		for _, ln := range l.Line {
-			if f := ln.Function; f != nil {
+			f := ln.Function
-				if f.ID == 0 || functions[f.ID] != f {
+			if f == nil {
-					return fmt.Errorf("inconsistent function %p: %d", f, f.ID)
+				return fmt.Errorf("location id: %d has a line with nil function", l.ID)
-				}
+			}
+			if f.ID == 0 || functions[f.ID] != f {
+				return fmt.Errorf("inconsistent function %p: %d", f, f.ID)
 			}
 		}
 	}

src/cmd/vendor/modules.txt

@@ -1,4 +1,4 @@
-# github.com/google/pprof v0.0.0-20200229191704-1ebb73c60ed3
+# github.com/google/pprof v0.0.0-20200708004538-1a94d8640e99
 ## explicit
 github.com/google/pprof/driver
 github.com/google/pprof/internal/binutils

src/crypto/x509/internal/macos/corefoundation.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin,amd64
+// +build darwin,!ios
 
 // Package macOS provides cgo-less wrappers for Core Foundation and
 // Security.framework, similarly to how package syscall provides access to

src/crypto/x509/internal/macos/corefoundation.s

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin,amd64
+// +build darwin,!ios
 
 #include "textflag.h"
 

src/crypto/x509/internal/macos/security.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin,amd64
+// +build darwin,!ios
 
 package macOS
 

src/crypto/x509/internal/macos/security.s

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin,amd64
+// +build darwin,!ios
 
 #include "textflag.h"
 

src/crypto/x509/root.go

@@ -4,7 +4,7 @@
 
 package x509
 
-//go:generate go run root_darwin_ios_gen.go -version 55161.80.1
+//go:generate go run root_ios_gen.go -version 55161.80.1
 
 import "sync"
 

src/crypto/x509/root_ios.go

@@ -1,7 +1,7 @@
-// Code generated by root_darwin_ios_gen.go -version 55161.80.1; DO NOT EDIT.
+// Code generated by root_ios_gen.go -version 55161.80.1; DO NOT EDIT.
 // Update the version in root.go and regenerate with "go generate".
 
-// +build darwin,arm64 darwin,amd64,ios
+// +build ios
 // +build !x509omitbundledroots
 
 package x509

src/crypto/x509/root_ios_gen.go

@@ -4,7 +4,7 @@
 
 // +build ignore
 
-// Generates root_darwin_iosx.go.
+// Generates root_ios.go.
 //
 // As of iOS 13, there is no API for querying the system trusted X.509 root
 // certificates.
@@ -37,10 +37,7 @@ import (
 )
 
 func main() {
-	// Temporarily name the file _iosx.go, to avoid restricting it to GOOS=ios,
+	var output = flag.String("output", "root_ios.go", "file name to write")
-	// as this is also used for darwin/arm64 (macOS).
-	// TODO: maybe use darwin/amd64 implementation on macOS arm64?
-	var output = flag.String("output", "root_darwin_iosx.go", "file name to write")
 	var version = flag.String("version", "", "security_certificates version")
 	flag.Parse()
 	if *version == "" {
@@ -159,10 +156,10 @@ func main() {
 	}
 }
 
-const header = `// Code generated by root_darwin_ios_gen.go -version %s; DO NOT EDIT.
+const header = `// Code generated by root_ios_gen.go -version %s; DO NOT EDIT.
 // Update the version in root.go and regenerate with "go generate".
 
-// +build darwin,arm64 darwin,amd64,ios
+// +build ios
 // +build !x509omitbundledroots
 
 package x509

src/go/build/build.go

@@ -409,19 +409,20 @@ type Package struct {
 	BinaryOnly    bool     // cannot be rebuilt from source (has //go:binary-only-package comment)
 
 	// Source files
-	GoFiles        []string // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
+	GoFiles           []string // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
-	CgoFiles       []string // .go source files that import "C"
+	CgoFiles          []string // .go source files that import "C"
-	IgnoredGoFiles []string // .go source files ignored for this build
+	IgnoredGoFiles    []string // .go source files ignored for this build (including ignored _test.go files)
-	InvalidGoFiles []string // .go source files with detected problems (parse error, wrong package name, and so on)
+	InvalidGoFiles    []string // .go source files with detected problems (parse error, wrong package name, and so on)
-	CFiles         []string // .c source files
+	IgnoredOtherFiles []string // non-.go source files ignored for this build
-	CXXFiles       []string // .cc, .cpp and .cxx source files
+	CFiles            []string // .c source files
-	MFiles         []string // .m (Objective-C) source files
+	CXXFiles          []string // .cc, .cpp and .cxx source files
-	HFiles         []string // .h, .hh, .hpp and .hxx source files
+	MFiles            []string // .m (Objective-C) source files
-	FFiles         []string // .f, .F, .for and .f90 Fortran source files
+	HFiles            []string // .h, .hh, .hpp and .hxx source files
-	SFiles         []string // .s source files
+	FFiles            []string // .f, .F, .for and .f90 Fortran source files
-	SwigFiles      []string // .swig files
+	SFiles            []string // .s source files
-	SwigCXXFiles   []string // .swigcxx files
+	SwigFiles         []string // .swig files
-	SysoFiles      []string // .syso system object files to add to archive
+	SwigCXXFiles      []string // .swigcxx files
+	SysoFiles         []string // .syso system object files to add to archive
 
 	// Cgo directives
 	CgoCFLAGS    []string // Cgo CFLAGS directives
@@ -816,46 +817,28 @@ Found:
 			continue
 		}
 		if !match {
-			if ext == ".go" {
+			if strings.HasPrefix(name, "_") || strings.HasPrefix(name, ".") {
+				// not due to build constraints - don't report
+			} else if ext == ".go" {
 				p.IgnoredGoFiles = append(p.IgnoredGoFiles, name)
+			} else if fileListForExt(p, ext) != nil {
+				p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, name)
 			}
 			continue
 		}
 
 		// Going to save the file. For non-Go files, can stop here.
 		switch ext {
-		case ".c":
+		case ".go":
-			p.CFiles = append(p.CFiles, name)
+			// keep going
-			continue
-		case ".cc", ".cpp", ".cxx":
-			p.CXXFiles = append(p.CXXFiles, name)
-			continue
-		case ".m":
-			p.MFiles = append(p.MFiles, name)
-			continue
-		case ".h", ".hh", ".hpp", ".hxx":
-			p.HFiles = append(p.HFiles, name)
-			continue
-		case ".f", ".F", ".for", ".f90":
-			p.FFiles = append(p.FFiles, name)
-			continue
-		case ".s":
-			p.SFiles = append(p.SFiles, name)
-			continue
 		case ".S", ".sx":
+			// special case for cgo, handled at end
 			Sfiles = append(Sfiles, name)
 			continue
-		case ".swig":
+		default:
-			p.SwigFiles = append(p.SwigFiles, name)
+			if list := fileListForExt(p, ext); list != nil {
-			continue
+				*list = append(*list, name)
-		case ".swigcxx":
+			}
-			p.SwigCXXFiles = append(p.SwigCXXFiles, name)
-			continue
-		case ".syso":
-			// binary objects to add to package archive
-			// Likely of the form foo_windows.syso, but
-			// the name was vetted above with goodOSArchFile.
-			p.SysoFiles = append(p.SysoFiles, name)
 			continue
 		}
 
@@ -996,6 +979,9 @@ Found:
 	if len(p.CgoFiles) > 0 {
 		p.SFiles = append(p.SFiles, Sfiles...)
 		sort.Strings(p.SFiles)
+	} else {
+		p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, Sfiles...)
+		sort.Strings(p.IgnoredOtherFiles)
 	}
 
 	if badGoError != nil {
@@ -1007,6 +993,30 @@ Found:
 	return p, pkgerr
 }
 
+func fileListForExt(p *Package, ext string) *[]string {
+	switch ext {
+	case ".c":
+		return &p.CFiles
+	case ".cc", ".cpp", ".cxx":
+		return &p.CXXFiles
+	case ".m":
+		return &p.MFiles
+	case ".h", ".hh", ".hpp", ".hxx":
+		return &p.HFiles
+	case ".f", ".F", ".for", ".f90":
+		return &p.FFiles
+	case ".s", ".S", ".sx":
+		return &p.SFiles
+	case ".swig":
+		return &p.SwigFiles
+	case ".swigcxx":
+		return &p.SwigCXXFiles
+	case ".syso":
+		return &p.SysoFiles
+	}
+	return nil
+}
+
 var errNoModules = errors.New("not using modules")
 
 // importGo checks whether it can use the go command to find the directory for path.
@@ -1302,6 +1312,8 @@ func (ctxt *Context) MatchFile(dir, name string) (match bool, err error) {
 	return
 }
 
+var dummyPkg Package
+
 // matchFile determines whether the file with the given name in the given directory
 // should be included in the package being constructed.
 // It returns the data read from the file.
@@ -1326,16 +1338,15 @@ func (ctxt *Context) matchFile(dir, name string, allTags map[string]bool, binary
 		return
 	}
 
-	switch ext {
+	if ext != ".go" && fileListForExt(&dummyPkg, ext) == nil {
-	case ".go", ".c", ".cc", ".cxx", ".cpp", ".m", ".s", ".h", ".hh", ".hpp", ".hxx", ".f", ".F", ".f90", ".S", ".sx", ".swig", ".swigcxx":
+		// skip
-		// tentatively okay - read to make sure
+		return
-	case ".syso":
+	}
+
+	if ext == ".syso" {
 		// binary, no reading
 		match = true
 		return
-	default:
-		// skip
-		return
 	}
 
 	filename = ctxt.joinPath(dir, name)
@@ -1360,8 +1371,8 @@ func (ctxt *Context) matchFile(dir, name string, allTags map[string]bool, binary
 	}
 
 	// Look for +build comments to accept or reject the file.
-	var sawBinaryOnly bool
+	ok, sawBinaryOnly := ctxt.shouldBuild(data, allTags)
-	if !ctxt.shouldBuild(data, allTags, &sawBinaryOnly) && !ctxt.UseAllFiles {
+	if !ok && !ctxt.UseAllFiles {
 		return
 	}
 
@@ -1411,10 +1422,11 @@ var binaryOnlyComment = []byte("//go:binary-only-package")
 //
 // marks the file as applicable only on Windows and Linux.
 //
-// If shouldBuild finds a //go:binary-only-package comment in the file,
+// For each build tag it consults, shouldBuild sets allTags[tag] = true.
-// it sets *binaryOnly to true. Otherwise it does not change *binaryOnly.
 //
-func (ctxt *Context) shouldBuild(content []byte, allTags map[string]bool, binaryOnly *bool) bool {
+// shouldBuild reports whether the file should be built
+// and whether a //go:binary-only-package comment was found.
+func (ctxt *Context) shouldBuild(content []byte, allTags map[string]bool) (shouldBuild bool, binaryOnly bool) {
 	sawBinaryOnly := false
 
 	// Pass 1. Identify leading run of // comments and blank lines,
@@ -1441,7 +1453,7 @@ func (ctxt *Context) shouldBuild(content []byte, allTags map[string]bool, binary
 
 	// Pass 2.  Process each line in the run.
 	p = content
-	allok := true
+	shouldBuild = true
 	for len(p) > 0 {
 		line := p
 		if i := bytes.IndexByte(line, '\n'); i >= 0 {
@@ -1468,17 +1480,13 @@ func (ctxt *Context) shouldBuild(content []byte, allTags map[string]bool, binary
 					}
 				}
 				if !ok {
-					allok = false
+					shouldBuild = false
 				}
 			}
 		}
 	}
 
-	if binaryOnly != nil && sawBinaryOnly {
+	return shouldBuild, sawBinaryOnly
-		*binaryOnly = true
-	}
-
-	return allok
 }
 
 // saveCgo saves the information from the #cgo lines in the import "C" comment.

src/go/build/build_test.go

@@ -6,6 +6,7 @@ package build
 
 import (
 	"flag"
+	"fmt"
 	"internal/testenv"
 	"io"
 	"io/ioutil"
@@ -120,7 +121,7 @@ func TestMultiplePackageImport(t *testing.T) {
 }
 
 func TestLocalDirectory(t *testing.T) {
-	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && runtime.GOARCH == "arm64" {
+	if runtime.GOOS == "ios" {
 		t.Skipf("skipping on %s/%s, no valid GOROOT", runtime.GOOS, runtime.GOARCH)
 	}
 
@@ -138,48 +139,78 @@ func TestLocalDirectory(t *testing.T) {
 	}
 }
 
+var shouldBuildTests = []struct {
+	content     string
+	tags        map[string]bool
+	binaryOnly  bool
+	shouldBuild bool
+}{
+	{
+		content: "// +build yes\n\n" +
+			"package main\n",
+		tags:        map[string]bool{"yes": true},
+		shouldBuild: true,
+	},
+	{
+		content: "// +build no yes\n\n" +
+			"package main\n",
+		tags:        map[string]bool{"yes": true, "no": true},
+		shouldBuild: true,
+	},
+	{
+		content: "// +build no,yes no\n\n" +
+			"package main\n",
+		tags:        map[string]bool{"yes": true, "no": true},
+		shouldBuild: false,
+	},
+	{
+		content: "// +build cgo\n\n" +
+			"// Copyright The Go Authors.\n\n" +
+			"// This package implements parsing of tags like\n" +
+			"// +build tag1\n" +
+			"package build",
+		tags:        map[string]bool{"cgo": true},
+		shouldBuild: false,
+	},
+	{
+		content: "// Copyright The Go Authors.\n\n" +
+			"package build\n\n" +
+			"// shouldBuild checks tags given by lines of the form\n" +
+			"// +build tag\n" +
+			"func shouldBuild(content []byte)\n",
+		tags:        map[string]bool{},
+		shouldBuild: true,
+	},
+	{
+		// too close to package line
+		content: "// +build yes\n" +
+			"package main\n",
+		tags:        map[string]bool{},
+		shouldBuild: true,
+	},
+	{
+		// too close to package line
+		content: "// +build no\n" +
+			"package main\n",
+		tags:        map[string]bool{},
+		shouldBuild: true,
+	},
+}
+
 func TestShouldBuild(t *testing.T) {
-	const file1 = "// +build tag1\n\n" +
+	for i, tt := range shouldBuildTests {
-		"package main\n"
+		t.Run(fmt.Sprint(i), func(t *testing.T) {
-	want1 := map[string]bool{"tag1": true}
+			ctx := &Context{BuildTags: []string{"yes"}}
-
+			tags := map[string]bool{}
-	const file2 = "// +build cgo\n\n" +
+			shouldBuild, binaryOnly := ctx.shouldBuild([]byte(tt.content), tags)
-		"// This package implements parsing of tags like\n" +
+			if shouldBuild != tt.shouldBuild || binaryOnly != tt.binaryOnly || !reflect.DeepEqual(tags, tt.tags) {
-		"// +build tag1\n" +
+				t.Errorf("mismatch:\n"+
-		"package build"
+					"have shouldBuild=%v, binaryOnly=%v, tags=%v\n"+
-	want2 := map[string]bool{"cgo": true}
+					"want shouldBuild=%v, binaryOnly=%v, tags=%v",
-
+					shouldBuild, binaryOnly, tags,
-	const file3 = "// Copyright The Go Authors.\n\n" +
+					tt.shouldBuild, tt.binaryOnly, tt.tags)
-		"package build\n\n" +
+			}
-		"// shouldBuild checks tags given by lines of the form\n" +
+		})
-		"// +build tag\n" +
-		"func shouldBuild(content []byte)\n"
-	want3 := map[string]bool{}
-
-	ctx := &Context{BuildTags: []string{"tag1"}}
-	m := map[string]bool{}
-	if !ctx.shouldBuild([]byte(file1), m, nil) {
-		t.Errorf("shouldBuild(file1) = false, want true")
-	}
-	if !reflect.DeepEqual(m, want1) {
-		t.Errorf("shouldBuild(file1) tags = %v, want %v", m, want1)
-	}
-
-	m = map[string]bool{}
-	if ctx.shouldBuild([]byte(file2), m, nil) {
-		t.Errorf("shouldBuild(file2) = true, want false")
-	}
-	if !reflect.DeepEqual(m, want2) {
-		t.Errorf("shouldBuild(file2) tags = %v, want %v", m, want2)
-	}
-
-	m = map[string]bool{}
-	ctx = &Context{BuildTags: nil}
-	if !ctx.shouldBuild([]byte(file3), m, nil) {
-		t.Errorf("shouldBuild(file3) = false, want true")
-	}
-	if !reflect.DeepEqual(m, want3) {
-		t.Errorf("shouldBuild(file3) tags = %v, want %v", m, want3)
 	}
 }
 
@@ -250,7 +281,7 @@ func TestMatchFile(t *testing.T) {
 }
 
 func TestImportCmd(t *testing.T) {
-	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && runtime.GOARCH == "arm64" {
+	if runtime.GOOS == "ios" {
 		t.Skipf("skipping on %s/%s, no valid GOROOT", runtime.GOOS, runtime.GOARCH)
 	}
 

src/go/build/deps_test.go

@@ -318,7 +318,6 @@ var depsRules = `
 	# so large dependencies must be kept out.
 	# This is a long-looking list but most of these
 	# are small with few dependencies.
-	# math/rand should probably be removed at some point.
 	CGO,
 	golang.org/x/net/dns/dnsmessage,
 	golang.org/x/net/lif,
@@ -327,11 +326,11 @@ var depsRules = `
 	internal/poll,
 	internal/singleflight,
 	internal/race,
-	math/rand,
 	os
 	< net;
 
 	fmt, unicode !< net;
+	math/rand !< net; # net uses runtime instead
 
 	# NET is net plus net-helper packages.
 	FMT, net
@@ -449,7 +448,7 @@ var depsRules = `
 	OS, compress/gzip, regexp
 	< internal/profile;
 
-	html/template, internal/profile, net/http, runtime/pprof, runtime/trace
+	html, internal/profile, net/http, runtime/pprof, runtime/trace
 	< net/http/pprof;
 
 	# RPC
@@ -479,7 +478,7 @@ var depsRules = `
 	CGO, OS, fmt
 	< os/signal/internal/pty;
 
-	NET, testing
+	NET, testing, math/rand
 	< golang.org/x/net/nettest;
 
 	FMT, container/heap, math/rand

src/hash/maphash/maphash.go

@@ -6,12 +6,11 @@
 // These hash functions are intended to be used to implement hash tables or
 // other data structures that need to map arbitrary strings or byte
 // sequences to a uniform distribution on unsigned 64-bit integers.
+// Each different instance of a hash table or data structure should use its own Seed.
 //
-// The hash functions are collision-resistant but not cryptographically secure.
+// The hash functions are not cryptographically secure.
 // (See crypto/sha256 and crypto/sha512 for cryptographic use.)
 //
-// The hash value of a given byte sequence is consistent within a
-// single process, but will be different in different processes.
 package maphash
 
 import "unsafe"

src/html/template/exec_test.go

@@ -1302,7 +1302,7 @@ func TestUnterminatedStringError(t *testing.T) {
 		t.Fatal("expected error")
 	}
 	str := err.Error()
-	if !strings.Contains(str, "X:3: unexpected unterminated raw quoted string") {
+	if !strings.Contains(str, "X:3: unterminated raw quoted string") {
 		t.Fatalf("unexpected error: %s", str)
 	}
 }