[dev.regabi] cmd/compile: move helpers into package base [generated]

[git-generate]
cd src/cmd/compile/internal/gc
rf '
	# Move EnableTrace constant into base, with the other flags.
	mv enableTrace EnableTrace
	mv EnableTrace base.go

	# Move compilation checks to base.
	mv instrumenting Instrumenting
	mv ispkgin Compiling
	mv omit_pkgs NoInstrumentPkgs
	mv norace_inst_pkgs NoRacePkgs
	mv Instrumenting Compiling NoInstrumentPkgs NoRacePkgs base.go

	# Move AutogeneratedPos to package base, next to Pos.
	mv autogeneratedPos AutogeneratedPos
	mv AutogeneratedPos print.go

	mv timings Timer

	mv base.go print.go timings.go cmd/compile/internal/base
'
cd ../base
rf '
	mv Instrumenting Flag.Cfg.Instrumenting
'

Change-Id: I534437fa75857d31531fc499d833c9930c0a06d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/279420
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

src/cmd/compile/internal/base/base.go

@@ -26,3 +26,54 @@ func Exit(code int) {
 	}
 	os.Exit(code)
 }
+
+// To enable tracing support (-t flag), set EnableTrace to true.
+const EnableTrace = false
+
+func Compiling(pkgs []string) bool {
+	if Ctxt.Pkgpath != "" {
+		for _, p := range pkgs {
+			if Ctxt.Pkgpath == p {
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
+// The racewalk pass is currently handled in three parts.
+//
+// First, for flag_race, it inserts calls to racefuncenter and
+// racefuncexit at the start and end (respectively) of each
+// function. This is handled below.
+//
+// Second, during buildssa, it inserts appropriate instrumentation
+// calls immediately before each memory load or store. This is handled
+// by the (*state).instrument method in ssa.go, so here we just set
+// the Func.InstrumentBody flag as needed. For background on why this
+// is done during SSA construction rather than a separate SSA pass,
+// see issue #19054.
+//
+// Third we remove calls to racefuncenter and racefuncexit, for leaf
+// functions without instrumented operations. This is done as part of
+// ssa opt pass via special rule.
+
+// TODO(dvyukov): do not instrument initialization as writes:
+// a := make([]int, 10)
+
+// Do not instrument the following packages at all,
+// at best instrumentation would cause infinite recursion.
+var NoInstrumentPkgs = []string{
+	"runtime/internal/atomic",
+	"runtime/internal/sys",
+	"runtime/internal/math",
+	"runtime",
+	"runtime/race",
+	"runtime/msan",
+	"internal/cpu",
+}
+
+// Don't insert racefuncenterfp/racefuncexit into the following packages.
+// Memory accesses in the packages are either uninteresting or will cause false positives.
+var NoRacePkgs = []string{"sync", "sync/atomic"}

src/cmd/compile/internal/base/flag.go

@@ -130,6 +130,9 @@ type CmdFlags struct {
 		ImportMap    map[string]string // set by -importmap OR -importcfg
 		PackageFile  map[string]string // set by -importcfg; nil means not in use
 		SpectreIndex bool              // set by -spectre=index or -spectre=all
+		// Whether we are adding any sort of code instrumentation, such as
+		// when the race detector is enabled.
+		Instrumenting bool
 	}
 }
 

src/cmd/compile/internal/base/print.go

@@ -260,3 +260,5 @@ func ExitIfErrors() {
 		ErrorExit()
 	}
 }
+
+var AutogeneratedPos src.XPos

src/cmd/compile/internal/base/timings.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.
 
-package gc
+package base
 
 import (
 	"fmt"
@@ -11,7 +11,7 @@ import (
 	"time"
 )
 
-var timings Timings
+var Timer Timings
 
 // Timings collects the execution times of labeled phases
 // which are added trough a sequence of Start/Stop calls.

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

@@ -288,7 +288,7 @@ func genhash(t *types.Type) *obj.LSym {
 		fmt.Printf("genhash %v %v %v\n", closure, sym, t)
 	}
 
-	base.Pos = autogeneratedPos // less confusing than end of input
+	base.Pos = base.AutogeneratedPos // less confusing than end of input
 	dclcontext = ir.PEXTERN
 
 	// func sym(p *T, h uintptr) uintptr
@@ -517,7 +517,7 @@ func geneq(t *types.Type) *obj.LSym {
 
 	// Autogenerate code for equality of structs and arrays.
 
-	base.Pos = autogeneratedPos // less confusing than end of input
+	base.Pos = base.AutogeneratedPos // less confusing than end of input
 	dclcontext = ir.PEXTERN
 
 	// func sym(p, q *T) bool

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

@@ -270,7 +270,7 @@ func reportTypeLoop(t *types.Type) {
 func dowidth(t *types.Type) {
 	// Calling dowidth when typecheck tracing enabled is not safe.
 	// See issue #33658.
-	if enableTrace && skipDowidthForTracing {
+	if base.EnableTrace && skipDowidthForTracing {
 		return
 	}
 	if Widthptr == 0 {

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

@@ -10,7 +10,6 @@ import (
 	"cmd/compile/internal/ssa"
 	"cmd/compile/internal/types"
 	"cmd/internal/obj"
-	"cmd/internal/src"
 	"sync"
 )
 
@@ -144,14 +143,8 @@ var Widthreg int
 
 var typecheckok bool
 
-// Whether we are adding any sort of code instrumentation, such as
-// when the race detector is enabled.
-var instrumenting bool
-
 var nodfp *ir.Name
 
-var autogeneratedPos src.XPos
-
 // interface to back end
 
 type Arch struct {

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

@@ -199,7 +199,7 @@ func makeABIWrapper(f *ir.Func, wrapperABI obj.ABI) {
 	savedclcontext := dclcontext
 	savedcurfn := Curfn
 
-	base.Pos = autogeneratedPos
+	base.Pos = base.AutogeneratedPos
 	dclcontext = ir.PEXTERN
 
 	// At the moment we don't support wrapping a method, we'd need machinery

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

@@ -844,7 +844,7 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 		return n
 	}
 
-	if instrumenting && isRuntimePkg(fn.Sym().Pkg) {
+	if base.Flag.Cfg.Instrumenting && isRuntimePkg(fn.Sym().Pkg) {
 		// Runtime package must not be instrumented.
 		// Instrument skips runtime package. However, some runtime code can be
 		// inlined into other packages and instrumented there. To avoid this,

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

@@ -58,7 +58,7 @@ var Target *ir.Package
 // arguments, type-checks the parsed Go package, compiles functions to machine
 // code, and finally writes the compiled package definition to disk.
 func Main(archInit func(*Arch)) {
-	timings.Start("fe", "init")
+	base.Timer.Start("fe", "init")
 
 	defer hidePanic()
 
@@ -123,7 +123,7 @@ func Main(archInit func(*Arch)) {
 	// changes in the binary.)
 	recordFlags("B", "N", "l", "msan", "race", "shared", "dynlink", "dwarflocationlists", "dwarfbasentries", "smallframes", "spectre")
 
-	if !enableTrace && base.Flag.LowerT {
+	if !base.EnableTrace && base.Flag.LowerT {
 		log.Fatalf("compiler not built with support for -t")
 	}
 
@@ -159,7 +159,7 @@ func Main(archInit func(*Arch)) {
 		readSymABIs(base.Flag.SymABIs, base.Ctxt.Pkgpath)
 	}
 
-	if ispkgin(omit_pkgs) {
+	if base.Compiling(base.NoInstrumentPkgs) {
 		base.Flag.Race = false
 		base.Flag.MSan = false
 	}
@@ -173,7 +173,7 @@ func Main(archInit func(*Arch)) {
 		msanpkg = types.NewPkg("runtime/msan", "")
 	}
 	if base.Flag.Race || base.Flag.MSan {
-		instrumenting = true
+		base.Flag.Cfg.Instrumenting = true
 	}
 	if base.Flag.Dwarf {
 		dwarf.EnableLogging(base.Debug.DwarfInl != 0)
@@ -205,7 +205,7 @@ func Main(archInit func(*Arch)) {
 	NeedITab = func(t, iface *types.Type) { itabname(t, iface) }
 	NeedRuntimeType = addsignat // TODO(rsc): typenamesym for lock?
 
-	autogeneratedPos = makePos(src.NewFileBase("<autogenerated>", "<autogenerated>"), 1, 0)
+	base.AutogeneratedPos = makePos(src.NewFileBase("<autogenerated>", "<autogenerated>"), 1, 0)
 
 	types.TypeLinkSym = func(t *types.Type) *obj.LSym {
 		return typenamesym(t).Linksym()
@@ -213,11 +213,11 @@ func Main(archInit func(*Arch)) {
 	TypecheckInit()
 
 	// Parse input.
-	timings.Start("fe", "parse")
+	base.Timer.Start("fe", "parse")
 	lines := parseFiles(flag.Args())
 	cgoSymABIs()
-	timings.Stop()
+	base.Timer.Stop()
-	timings.AddEvent(int64(lines), "lines")
+	base.Timer.AddEvent(int64(lines), "lines")
 	recordPackageName()
 
 	// Typecheck.
@@ -233,7 +233,7 @@ func Main(archInit func(*Arch)) {
 	}
 
 	// Inlining
-	timings.Start("fe", "inlining")
+	base.Timer.Start("fe", "inlining")
 	if base.Flag.LowerL != 0 {
 		InlinePackage()
 	}
@@ -254,7 +254,7 @@ func Main(archInit func(*Arch)) {
 	// or else the stack copier will not update it.
 	// Large values are also moved off stack in escape analysis;
 	// because large values may contain pointers, it must happen early.
-	timings.Start("fe", "escapes")
+	base.Timer.Start("fe", "escapes")
 	escapes(Target.Decls)
 
 	// Collect information for go:nowritebarrierrec
@@ -268,7 +268,7 @@ func Main(archInit func(*Arch)) {
 	// Transform closure bodies to properly reference captured variables.
 	// This needs to happen before walk, because closures must be transformed
 	// before walk reaches a call of a closure.
-	timings.Start("fe", "xclosures")
+	base.Timer.Start("fe", "xclosures")
 	for _, n := range Target.Decls {
 		if n.Op() == ir.ODCLFUNC {
 			n := n.(*ir.Func)
@@ -292,7 +292,7 @@ func Main(archInit func(*Arch)) {
 
 	// Compile top level functions.
 	// Don't use range--walk can add functions to Target.Decls.
-	timings.Start("be", "compilefuncs")
+	base.Timer.Start("be", "compilefuncs")
 	fcount := int64(0)
 	for i := 0; i < len(Target.Decls); i++ {
 		n := Target.Decls[i]
@@ -301,7 +301,7 @@ func Main(archInit func(*Arch)) {
 			fcount++
 		}
 	}
-	timings.AddEvent(fcount, "funcs")
+	base.Timer.AddEvent(fcount, "funcs")
 
 	compileFunctions()
 
@@ -320,7 +320,7 @@ func Main(archInit func(*Arch)) {
 	}
 
 	// Write object data to disk.
-	timings.Start("be", "dumpobj")
+	base.Timer.Start("be", "dumpobj")
 	dumpdata()
 	base.Ctxt.NumberSyms()
 	dumpobj()
@@ -339,7 +339,7 @@ func Main(archInit func(*Arch)) {
 	base.ExitIfErrors()
 
 	base.FlushErrors()
-	timings.Stop()
+	base.Timer.Stop()
 
 	if base.Flag.Bench != "" {
 		if err := writebench(base.Flag.Bench); err != nil {
@@ -397,7 +397,7 @@ func writebench(filename string) error {
 	fmt.Fprintln(&buf, "commit:", objabi.Version)
 	fmt.Fprintln(&buf, "goos:", runtime.GOOS)
 	fmt.Fprintln(&buf, "goarch:", runtime.GOARCH)
-	timings.Write(&buf, "BenchmarkCompile:"+base.Ctxt.Pkgpath+":")
+	base.Timer.Write(&buf, "BenchmarkCompile:"+base.Ctxt.Pkgpath+":")
 
 	n, err := f.Write(buf.Bytes())
 	if err != nil {

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

@@ -362,7 +362,7 @@ func (o *Order) stmtList(l ir.Nodes) {
 // and rewrites it to:
 //  m = OMAKESLICECOPY([]T, x, s); nil
 func orderMakeSliceCopy(s []ir.Node) {
-	if base.Flag.N != 0 || instrumenting {
+	if base.Flag.N != 0 || base.Flag.Cfg.Instrumenting {
 		return
 	}
 	if len(s) < 2 || s[0] == nil || s[0].Op() != ir.OAS || s[1] == nil || s[1].Op() != ir.OCOPY {
@@ -580,7 +580,7 @@ func (o *Order) mapAssign(n ir.Node) {
 					m.Index = o.copyExpr(m.Index)
 				}
 				fallthrough
-			case instrumenting && n.Op() == ir.OAS2FUNC && !ir.IsBlank(m):
+			case base.Flag.Cfg.Instrumenting && n.Op() == ir.OAS2FUNC && !ir.IsBlank(m):
 				t := o.newTemp(m.Type(), false)
 				n.Lhs[i] = t
 				a := ir.NewAssignStmt(base.Pos, m, t)
@@ -639,7 +639,7 @@ func (o *Order) stmt(n ir.Node) {
 		n.X = o.expr(n.X, nil)
 		n.Y = o.expr(n.Y, nil)
 
-		if instrumenting || n.X.Op() == ir.OINDEXMAP && (n.AsOp == ir.ODIV || n.AsOp == ir.OMOD) {
+		if base.Flag.Cfg.Instrumenting || n.X.Op() == ir.OINDEXMAP && (n.AsOp == ir.ODIV || n.AsOp == ir.OMOD) {
 			// Rewrite m[k] op= r into m[k] = m[k] op r so
 			// that we can ensure that if op panics
 			// because r is zero, the panic happens before
@@ -1008,7 +1008,7 @@ func (o *Order) stmt(n ir.Node) {
 		t := o.markTemp()
 		n.Chan = o.expr(n.Chan, nil)
 		n.Value = o.expr(n.Value, nil)
-		if instrumenting {
+		if base.Flag.Cfg.Instrumenting {
 			// Force copying to the stack so that (chan T)(nil) <- x
 			// is still instrumented as a read of x.
 			n.Value = o.copyExpr(n.Value)
@@ -1156,7 +1156,7 @@ func (o *Order) expr1(n, lhs ir.Node) ir.Node {
 			// conversions. See copyExpr a few lines below.
 			needCopy = mapKeyReplaceStrConv(n.Index)
 
-			if instrumenting {
+			if base.Flag.Cfg.Instrumenting {
 				// Race detector needs the copy.
 				needCopy = true
 			}
@@ -1194,7 +1194,7 @@ func (o *Order) expr1(n, lhs ir.Node) ir.Node {
 			// together. See golang.org/issue/15329.
 			o.init(call)
 			o.call(call)
-			if lhs == nil || lhs.Op() != ir.ONAME || instrumenting {
+			if lhs == nil || lhs.Op() != ir.ONAME || base.Flag.Cfg.Instrumenting {
 				return o.copyExpr(n)
 			}
 		} else {
@@ -1267,7 +1267,7 @@ func (o *Order) expr1(n, lhs ir.Node) ir.Node {
 			o.call(n)
 		}
 
-		if lhs == nil || lhs.Op() != ir.ONAME || instrumenting {
+		if lhs == nil || lhs.Op() != ir.ONAME || base.Flag.Cfg.Instrumenting {
 			return o.copyExpr(n)
 		}
 		return n
@@ -1332,7 +1332,7 @@ func (o *Order) expr1(n, lhs ir.Node) ir.Node {
 	case ir.ODOTTYPE, ir.ODOTTYPE2:
 		n := n.(*ir.TypeAssertExpr)
 		n.X = o.expr(n.X, nil)
-		if !isdirectiface(n.Type()) || instrumenting {
+		if !isdirectiface(n.Type()) || base.Flag.Cfg.Instrumenting {
 			return o.copyExprClear(n)
 		}
 		return n

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

@@ -12,60 +12,12 @@ import (
 	"cmd/internal/sys"
 )
 
-// The racewalk pass is currently handled in three parts.
-//
-// First, for flag_race, it inserts calls to racefuncenter and
-// racefuncexit at the start and end (respectively) of each
-// function. This is handled below.
-//
-// Second, during buildssa, it inserts appropriate instrumentation
-// calls immediately before each memory load or store. This is handled
-// by the (*state).instrument method in ssa.go, so here we just set
-// the Func.InstrumentBody flag as needed. For background on why this
-// is done during SSA construction rather than a separate SSA pass,
-// see issue #19054.
-//
-// Third we remove calls to racefuncenter and racefuncexit, for leaf
-// functions without instrumented operations. This is done as part of
-// ssa opt pass via special rule.
-
-// TODO(dvyukov): do not instrument initialization as writes:
-// a := make([]int, 10)
-
-// Do not instrument the following packages at all,
-// at best instrumentation would cause infinite recursion.
-var omit_pkgs = []string{
-	"runtime/internal/atomic",
-	"runtime/internal/sys",
-	"runtime/internal/math",
-	"runtime",
-	"runtime/race",
-	"runtime/msan",
-	"internal/cpu",
-}
-
-// Don't insert racefuncenterfp/racefuncexit into the following packages.
-// Memory accesses in the packages are either uninteresting or will cause false positives.
-var norace_inst_pkgs = []string{"sync", "sync/atomic"}
-
-func ispkgin(pkgs []string) bool {
-	if base.Ctxt.Pkgpath != "" {
-		for _, p := range pkgs {
-			if base.Ctxt.Pkgpath == p {
-				return true
-			}
-		}
-	}
-
-	return false
-}
-
 func instrument(fn *ir.Func) {
 	if fn.Pragma&ir.Norace != 0 || (fn.Sym().Linksym() != nil && fn.Sym().Linksym().ABIWrapper()) {
 		return
 	}
 
-	if !base.Flag.Race || !ispkgin(norace_inst_pkgs) {
+	if !base.Flag.Race || !base.Compiling(base.NoRacePkgs) {
 		fn.SetInstrumentBody(true)
 	}
 

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

@@ -460,7 +460,7 @@ func walkrange(nrange *ir.RangeStmt) ir.Node {
 //
 // where == for keys of map m is reflexive.
 func isMapClear(n *ir.RangeStmt) bool {
-	if base.Flag.N != 0 || instrumenting {
+	if base.Flag.N != 0 || base.Flag.Cfg.Instrumenting {
 		return false
 	}
 
@@ -523,7 +523,7 @@ func mapClear(m ir.Node) ir.Node {
 //
 // Parameters are as in walkrange: "for v1, v2 = range a".
 func arrayClear(loop *ir.RangeStmt, v1, v2, a ir.Node) ir.Node {
-	if base.Flag.N != 0 || instrumenting {
+	if base.Flag.N != 0 || base.Flag.Cfg.Instrumenting {
 		return nil
 	}
 

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

@@ -2281,7 +2281,7 @@ func (s *state) expr(n ir.Node) *ssa.Value {
 			return nil
 		}
 
-		if instrumenting {
+		if base.Flag.Cfg.Instrumenting {
 			// These appear to be fine, but they fail the
 			// integer constraint below, so okay them here.
 			// Sample non-integer conversion: map[string]string -> *uint8
@@ -3490,7 +3490,7 @@ func initSSATables() {
 	}
 
 	/******** runtime ********/
-	if !instrumenting {
+	if !base.Flag.Cfg.Instrumenting {
 		add("runtime", "slicebytetostringtmp",
 			func(s *state, n *ir.CallExpr, args []*ssa.Value) *ssa.Value {
 				// Compiler frontend optimizations emit OBYTES2STRTMP nodes

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

@@ -613,7 +613,7 @@ func calcHasCall(n ir.Node) bool {
 	case ir.OANDAND, ir.OOROR:
 		// hard with instrumented code
 		n := n.(*ir.LogicalExpr)
-		if instrumenting {
+		if base.Flag.Cfg.Instrumenting {
 			return true
 		}
 		return n.X.HasCall() || n.Y.HasCall()
@@ -1209,7 +1209,7 @@ func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym) {
 		return
 	}
 
-	base.Pos = autogeneratedPos
+	base.Pos = base.AutogeneratedPos
 	dclcontext = ir.PEXTERN
 
 	tfn := ir.NewFuncType(base.Pos,
@@ -1243,7 +1243,7 @@ func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym) {
 	// the TOC to the appropriate value for that module. But if it returns
 	// directly to the wrapper's caller, nothing will reset it to the correct
 	// value for that function.
-	if !instrumenting && rcvr.IsPtr() && methodrcvr.IsPtr() && method.Embedded != 0 && !isifacemethod(method.Type) && !(thearch.LinkArch.Name == "ppc64le" && base.Ctxt.Flag_dynlink) {
+	if !base.Flag.Cfg.Instrumenting && rcvr.IsPtr() && methodrcvr.IsPtr() && method.Embedded != 0 && !isifacemethod(method.Type) && !(thearch.LinkArch.Name == "ppc64le" && base.Ctxt.Flag_dynlink) {
 		// generate tail call: adjust pointer receiver and jump to embedded method.
 		left := dot.X // skip final .M
 		if !left.Type().IsPtr() {

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

@@ -25,7 +25,7 @@ func TypecheckInit() {
 	types.Dowidth = dowidth
 	initUniverse()
 	dclcontext = ir.PEXTERN
-	timings.Start("fe", "loadsys")
+	base.Timer.Start("fe", "loadsys")
 	loadsys()
 }
 
@@ -45,7 +45,7 @@ func TypecheckPackage() {
 	//   TODO(gri) Remove this again once we have a fix for #25838.
 
 	// Don't use range--typecheck can add closures to Target.Decls.
-	timings.Start("fe", "typecheck", "top1")
+	base.Timer.Start("fe", "typecheck", "top1")
 	for i := 0; i < len(Target.Decls); i++ {
 		n := Target.Decls[i]
 		if op := n.Op(); op != ir.ODCL && op != ir.OAS && op != ir.OAS2 && (op != ir.ODCLTYPE || !n.(*ir.Decl).X.Name().Alias()) {
@@ -57,7 +57,7 @@ func TypecheckPackage() {
 	//   To check interface assignments, depends on phase 1.
 
 	// Don't use range--typecheck can add closures to Target.Decls.
-	timings.Start("fe", "typecheck", "top2")
+	base.Timer.Start("fe", "typecheck", "top2")
 	for i := 0; i < len(Target.Decls); i++ {
 		n := Target.Decls[i]
 		if op := n.Op(); op == ir.ODCL || op == ir.OAS || op == ir.OAS2 || op == ir.ODCLTYPE && n.(*ir.Decl).X.Name().Alias() {
@@ -67,7 +67,7 @@ func TypecheckPackage() {
 
 	// Phase 3: Type check function bodies.
 	// Don't use range--typecheck can add closures to Target.Decls.
-	timings.Start("fe", "typecheck", "func")
+	base.Timer.Start("fe", "typecheck", "func")
 	var fcount int64
 	for i := 0; i < len(Target.Decls); i++ {
 		n := Target.Decls[i]
@@ -80,7 +80,7 @@ func TypecheckPackage() {
 	// Phase 4: Check external declarations.
 	// TODO(mdempsky): This should be handled when type checking their
 	// corresponding ODCL nodes.
-	timings.Start("fe", "typecheck", "externdcls")
+	base.Timer.Start("fe", "typecheck", "externdcls")
 	for i, n := range Target.Externs {
 		if n.Op() == ir.ONAME {
 			Target.Externs[i] = typecheck(Target.Externs[i], ctxExpr)
@@ -93,7 +93,7 @@ func TypecheckPackage() {
 	// Phase 6: Decide how to capture closed variables.
 	// This needs to run before escape analysis,
 	// because variables captured by value do not escape.
-	timings.Start("fe", "capturevars")
+	base.Timer.Start("fe", "capturevars")
 	for _, n := range Target.Decls {
 		if n.Op() == ir.ODCLFUNC {
 			n := n.(*ir.Func)
@@ -162,9 +162,6 @@ func TypecheckImports() {
 	}
 }
 
-// To enable tracing support (-t flag), set enableTrace to true.
-const enableTrace = false
-
 var traceIndent []byte
 var skipDowidthForTracing bool
 
@@ -234,7 +231,7 @@ func resolve(n ir.Node) (res ir.Node) {
 	}
 
 	// only trace if there's work to do
-	if enableTrace && base.Flag.LowerT {
+	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("resolve", n)(&res)
 	}
 
@@ -379,7 +376,7 @@ func typecheck(n ir.Node, top int) (res ir.Node) {
 	}
 
 	// only trace if there's work to do
-	if enableTrace && base.Flag.LowerT {
+	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("typecheck", n)(&res)
 	}
 
@@ -568,7 +565,7 @@ func indexlit(n ir.Node) ir.Node {
 
 // typecheck1 should ONLY be called from typecheck.
 func typecheck1(n ir.Node, top int) (res ir.Node) {
-	if enableTrace && base.Flag.LowerT {
+	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("typecheck1", n)(&res)
 	}
 
@@ -2552,7 +2549,7 @@ func lookdot1(errnode ir.Node, s *types.Sym, t *types.Type, fs *types.Fields, do
 // typecheckMethodExpr checks selector expressions (ODOT) where the
 // base expression is a type expression (OTYPE).
 func typecheckMethodExpr(n *ir.SelectorExpr) (res ir.Node) {
-	if enableTrace && base.Flag.LowerT {
+	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("typecheckMethodExpr", n)(&res)
 	}
 
@@ -2991,7 +2988,7 @@ func pushtype(nn ir.Node, t *types.Type) ir.Node {
 // The result of typecheckcomplit MUST be assigned back to n, e.g.
 // 	n.Left = typecheckcomplit(n.Left)
 func typecheckcomplit(n *ir.CompLitExpr) (res ir.Node) {
-	if enableTrace && base.Flag.LowerT {
+	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("typecheckcomplit", n)(&res)
 	}
 
@@ -3435,7 +3432,7 @@ func samesafeexpr(l ir.Node, r ir.Node) bool {
 // if this assignment is the definition of a var on the left side,
 // fill in the var's type.
 func typecheckas(n *ir.AssignStmt) {
-	if enableTrace && base.Flag.LowerT {
+	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("typecheckas", n)(nil)
 	}
 
@@ -3493,7 +3490,7 @@ func checkassignto(src *types.Type, dst ir.Node) {
 }
 
 func typecheckas2(n *ir.AssignListStmt) {
-	if enableTrace && base.Flag.LowerT {
+	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("typecheckas2", n)(nil)
 	}
 
@@ -3627,7 +3624,7 @@ out:
 // To be called by typecheck, not directly.
 // (Call typecheckFunc instead.)
 func typecheckfunc(n *ir.Func) {
-	if enableTrace && base.Flag.LowerT {
+	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("typecheckfunc", n)(nil)
 	}
 
@@ -3691,7 +3688,7 @@ func checkMapKeys() {
 }
 
 func typecheckdeftype(n *ir.Name) {
-	if enableTrace && base.Flag.LowerT {
+	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("typecheckdeftype", n)(nil)
 	}
 
@@ -3723,7 +3720,7 @@ func typecheckdeftype(n *ir.Name) {
 }
 
 func typecheckdef(n ir.Node) {
-	if enableTrace && base.Flag.LowerT {
+	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("typecheckdef", n)(nil)
 	}
 

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

@@ -85,7 +85,7 @@ func walk(fn *ir.Func) {
 		ir.DumpList(s, Curfn.Enter)
 	}
 
-	if instrumenting {
+	if base.Flag.Cfg.Instrumenting {
 		instrument(fn)
 	}
 }
@@ -738,7 +738,7 @@ func walkexpr1(n ir.Node, init *ir.Nodes) ir.Node {
 			return as
 		}
 
-		if !instrumenting && isZero(as.Y) {
+		if !base.Flag.Cfg.Instrumenting && isZero(as.Y) {
 			return as
 		}
 
@@ -1311,7 +1311,7 @@ func walkexpr1(n ir.Node, init *ir.Nodes) ir.Node {
 		panic("unreachable")
 
 	case ir.OCOPY:
-		return copyany(n.(*ir.BinaryExpr), init, instrumenting && !base.Flag.CompilingRuntime)
+		return copyany(n.(*ir.BinaryExpr), init, base.Flag.Cfg.Instrumenting && !base.Flag.CompilingRuntime)
 
 	case ir.OCLOSE:
 		// cannot use chanfn - closechan takes any, not chan any
@@ -1597,7 +1597,7 @@ func walkexpr1(n ir.Node, init *ir.Nodes) ir.Node {
 	case ir.OBYTES2STRTMP:
 		n := n.(*ir.ConvExpr)
 		n.X = walkexpr(n.X, init)
-		if !instrumenting {
+		if !base.Flag.Cfg.Instrumenting {
 			// Let the backend handle OBYTES2STRTMP directly
 			// to avoid a function call to slicebytetostringtmp.
 			return n
@@ -1975,7 +1975,7 @@ func walkCall(n *ir.CallExpr, init *ir.Nodes) {
 		} else {
 			t = params.Field(i).Type
 		}
-		if instrumenting || fncall(arg, t) {
+		if base.Flag.Cfg.Instrumenting || fncall(arg, t) {
 			// make assignment of fncall to tempAt
 			tmp := temp(t)
 			a := convas(ir.NewAssignStmt(base.Pos, tmp, arg), init)
@@ -2873,7 +2873,7 @@ func appendslice(n *ir.CallExpr, init *ir.Nodes) ir.Node {
 		ptr1, len1 := backingArrayPtrLen(cheapexpr(slice, &nodes))
 		ptr2, len2 := backingArrayPtrLen(l2)
 		ncopy = mkcall1(fn, types.Types[types.TINT], &nodes, typename(elemtype), ptr1, len1, ptr2, len2)
-	} else if instrumenting && !base.Flag.CompilingRuntime {
+	} else if base.Flag.Cfg.Instrumenting && !base.Flag.CompilingRuntime {
 		// rely on runtime to instrument:
 		//  copy(s[len(l1):], l2)
 		// l2 can be a slice or string.
@@ -2914,7 +2914,7 @@ func appendslice(n *ir.CallExpr, init *ir.Nodes) ir.Node {
 // isAppendOfMake reports whether n is of the form append(x , make([]T, y)...).
 // isAppendOfMake assumes n has already been typechecked.
 func isAppendOfMake(n ir.Node) bool {
-	if base.Flag.N != 0 || instrumenting {
+	if base.Flag.N != 0 || base.Flag.Cfg.Instrumenting {
 		return false
 	}
 
@@ -3125,7 +3125,7 @@ func walkappend(n *ir.CallExpr, init *ir.Nodes, dst ir.Node) ir.Node {
 
 	// General case, with no function calls left as arguments.
 	// Leave for gen, except that instrumentation requires old form.
-	if !instrumenting || base.Flag.CompilingRuntime {
+	if !base.Flag.Cfg.Instrumenting || base.Flag.CompilingRuntime {
 		return n
 	}
 
@@ -4055,7 +4055,7 @@ func canMergeLoads() bool {
 // isRuneCount reports whether n is of the form len([]rune(string)).
 // These are optimized into a call to runtime.countrunes.
 func isRuneCount(n ir.Node) bool {
-	return base.Flag.N == 0 && !instrumenting && n.Op() == ir.OLEN && n.(*ir.UnaryExpr).X.Op() == ir.OSTR2RUNES
+	return base.Flag.N == 0 && !base.Flag.Cfg.Instrumenting && n.Op() == ir.OLEN && n.(*ir.UnaryExpr).X.Op() == ir.OSTR2RUNES
 }
 
 func walkCheckPtrAlignment(n *ir.ConvExpr, init *ir.Nodes, count ir.Node) ir.Node {