[dev.regabi] cmd/compile: narrow interface between ir and types

Narrow the interface between package ir and package types
to make it easier to clean up the type formatting code all in one place.

Also introduce ir.BlankSym for use by OrigSym, so that later
OrigSym can move to package types without needing to reference
a variable of type ir.Node.

Passes buildall w/ toolstash -cmp.

Change-Id: I39fa419a1c8fb3318203e31cacc8d06399deeff9
Reviewed-on: https://go-review.googlesource.com/c/go/+/275776
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

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

@@ -212,15 +212,10 @@ func Main(archInit func(*Arch)) {
 	// would lead to import cycles)
 	types.Widthptr = Widthptr
 	types.Dowidth = dowidth
-	types.Fatalf = base.Fatalf
 	ir.InstallTypeFormats()
 	types.TypeLinkSym = func(t *types.Type) *obj.LSym {
 		return typenamesym(t).Linksym()
 	}
-	types.FmtLeft = int(ir.FmtLeft)
-	types.FmtUnsigned = int(ir.FmtUnsigned)
-	types.FErr = int(ir.FErr)
-	types.Ctxt = base.Ctxt
 
 	initUniverse()
 

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

@@ -182,6 +182,7 @@ func initUniverse() {
 	ir.AsNode(s.Def).SetSym(lookup("false"))
 
 	s = lookup("_")
+	ir.BlankSym = s
 	s.Block = -100
 	s.Def = NewName(s)
 	types.Types[types.TBLANK] = types.New(types.TBLANK)

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

@@ -339,7 +339,8 @@ func symFormat(s *types.Sym, f fmt.State, verb rune, mode FmtMode) {
 
 func smodeString(s *types.Sym, mode FmtMode) string { return sconv(s, 0, mode) }
 
-// See #16897 before changing the implementation of sconv.
+// See #16897 for details about performance implications
+// before changing the implementation of sconv.
 func sconv(s *types.Sym, flag FmtFlag, mode FmtMode) string {
 	if flag&FmtLong != 0 {
 		panic("linksymfmt")
@@ -472,17 +473,23 @@ var fmtBufferPool = sync.Pool{
 }
 
 func InstallTypeFormats() {
-	types.Sconv = func(s *types.Sym, flag, mode int) string {
+	types.SymString = func(s *types.Sym) string {
-		return sconv(s, FmtFlag(flag), FmtMode(mode))
+		return sconv(s, 0, FErr)
 	}
-	types.Tconv = func(t *types.Type, flag, mode int) string {
+	types.TypeString = func(t *types.Type) string {
-		return tconv(t, FmtFlag(flag), FmtMode(mode))
+		return tconv(t, 0, FErr)
 	}
-	types.FormatSym = func(sym *types.Sym, s fmt.State, verb rune, mode int) {
+	types.TypeShortString = func(t *types.Type) string {
-		symFormat(sym, s, verb, FmtMode(mode))
+		return tconv(t, FmtLeft, FErr)
 	}
-	types.FormatType = func(t *types.Type, s fmt.State, verb rune, mode int) {
+	types.TypeLongString = func(t *types.Type) string {
-		typeFormat(t, s, verb, FmtMode(mode))
+		return tconv(t, FmtLeft|FmtUnsigned, FErr)
+	}
+	types.FormatSym = func(sym *types.Sym, s fmt.State, verb rune) {
+		symFormat(sym, s, verb, FErr)
+	}
+	types.FormatType = func(t *types.Type, s fmt.State, verb rune) {
+		typeFormat(t, s, verb, FErr)
 	}
 }
 

src/cmd/compile/internal/ir/node.go

@@ -654,6 +654,8 @@ func AsNode(n types.Object) Node {
 
 var BlankNode Node
 
+var BlankSym *types.Sym
+
 // origSym returns the original symbol written by the user.
 func OrigSym(s *types.Sym) *types.Sym {
 	if s == nil {
@@ -666,7 +668,7 @@ func OrigSym(s *types.Sym) *types.Sym {
 			return nil
 		case 'b': // originally the blank identifier _
 			// TODO(mdempsky): Does s.Pkg matter here?
-			return BlankNode.Sym()
+			return BlankSym
 		}
 		return s
 	}

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

@@ -12,7 +12,6 @@ import (
 	"cmd/internal/obj/s390x"
 	"cmd/internal/obj/x86"
 	"cmd/internal/src"
-	"fmt"
 	"testing"
 )
 
@@ -138,19 +137,7 @@ func init() {
 	// Initialize just enough of the universe and the types package to make our tests function.
 	// TODO(josharian): move universe initialization to the types package,
 	// so this test setup can share it.
-
+	ir.InstallTypeFormats()
-	types.Tconv = func(t *types.Type, flag, mode int) string {
-		return t.Kind().String()
-	}
-	types.Sconv = func(s *types.Sym, flag, mode int) string {
-		return "sym"
-	}
-	types.FormatSym = func(sym *types.Sym, s fmt.State, verb rune, mode int) {
-		fmt.Fprintf(s, "sym")
-	}
-	types.FormatType = func(t *types.Type, s fmt.State, verb rune, mode int) {
-		fmt.Fprintf(s, "%v", t.Kind())
-	}
 	types.Dowidth = func(t *types.Type) {}
 
 	for _, typ := range [...]struct {

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

@@ -4,7 +4,10 @@
 
 package types
 
-import "cmd/internal/src"
+import (
+	"cmd/compile/internal/base"
+	"cmd/internal/src"
+)
 
 // Declaration stack & operations
 
@@ -56,7 +59,7 @@ func Popdcl() {
 		d.sym = nil
 		d.def = nil
 	}
-	Fatalf("popdcl: no stack mark")
+	base.Fatalf("popdcl: no stack mark")
 }
 
 // Markdcl records the start of a new block scope for declarations.

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

@@ -5,6 +5,7 @@
 package types
 
 import (
+	"cmd/compile/internal/base"
 	"cmd/internal/obj"
 	"cmd/internal/src"
 	"unicode"
@@ -88,9 +89,9 @@ func (sym *Sym) Linksym() *obj.LSym {
 	}
 	if sym.Func() {
 		// This is a function symbol. Mark it as "internal ABI".
-		return Ctxt.LookupABIInit(sym.LinksymName(), obj.ABIInternal, initPkg)
+		return base.Ctxt.LookupABIInit(sym.LinksymName(), obj.ABIInternal, initPkg)
 	}
-	return Ctxt.LookupInit(sym.LinksymName(), initPkg)
+	return base.Ctxt.LookupInit(sym.LinksymName(), initPkg)
 }
 
 // Less reports whether symbol a is ordered before symbol b.

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

@@ -231,7 +231,7 @@ func (t *Type) Pkg() *Pkg {
 	case TINTER:
 		return t.Extra.(*Interface).pkg
 	default:
-		Fatalf("Pkg: unexpected kind: %v", t)
+		base.Fatalf("Pkg: unexpected kind: %v", t)
 		return nil
 	}
 }
@@ -501,7 +501,7 @@ func New(et Kind) *Type {
 // NewArray returns a new fixed-length array Type.
 func NewArray(elem *Type, bound int64) *Type {
 	if bound < 0 {
-		Fatalf("NewArray: invalid bound %v", bound)
+		base.Fatalf("NewArray: invalid bound %v", bound)
 	}
 	t := New(TARRAY)
 	t.Extra = &Array{Elem: elem, Bound: bound}
@@ -513,7 +513,7 @@ func NewArray(elem *Type, bound int64) *Type {
 func NewSlice(elem *Type) *Type {
 	if t := elem.cache.slice; t != nil {
 		if t.Elem() != elem {
-			Fatalf("elem mismatch")
+			base.Fatalf("elem mismatch")
 		}
 		return t
 	}
@@ -569,12 +569,12 @@ var NewPtrCacheEnabled = true
 // NewPtr returns the pointer type pointing to t.
 func NewPtr(elem *Type) *Type {
 	if elem == nil {
-		Fatalf("NewPtr: pointer to elem Type is nil")
+		base.Fatalf("NewPtr: pointer to elem Type is nil")
 	}
 
 	if t := elem.cache.ptr; t != nil {
 		if t.Elem() != elem {
-			Fatalf("NewPtr: elem mismatch")
+			base.Fatalf("NewPtr: elem mismatch")
 		}
 		return t
 	}
@@ -629,7 +629,7 @@ func SubstAny(t *Type, types *[]*Type) *Type {
 
 	case TANY:
 		if len(*types) == 0 {
-			Fatalf("substArgTypes: not enough argument types")
+			base.Fatalf("substArgTypes: not enough argument types")
 		}
 		t = (*types)[0]
 		*types = (*types)[1:]
@@ -730,7 +730,7 @@ func (t *Type) copy() *Type {
 		x := *t.Extra.(*Array)
 		nt.Extra = &x
 	case TTUPLE, TSSA, TRESULTS:
-		Fatalf("ssa types cannot be copied")
+		base.Fatalf("ssa types cannot be copied")
 	}
 	// TODO(mdempsky): Find out why this is necessary and explain.
 	if t.underlying == t {
@@ -746,7 +746,7 @@ func (f *Field) Copy() *Field {
 
 func (t *Type) wantEtype(et Kind) {
 	if t.kind != et {
-		Fatalf("want %v, but have %v", et, t)
+		base.Fatalf("want %v, but have %v", et, t)
 	}
 }
 
@@ -811,7 +811,7 @@ func (t *Type) Elem() *Type {
 	case TMAP:
 		return t.Extra.(*Map).Elem
 	}
-	Fatalf("Type.Elem %s", t.kind)
+	base.Fatalf("Type.Elem %s", t.kind)
 	return nil
 }
 
@@ -850,7 +850,7 @@ func (t *Type) Fields() *Fields {
 		Dowidth(t)
 		return &t.Extra.(*Interface).Fields
 	}
-	Fatalf("Fields: type %v does not have fields", t)
+	base.Fatalf("Fields: type %v does not have fields", t)
 	return nil
 }
 
@@ -874,7 +874,7 @@ func (t *Type) SetFields(fields []*Field) {
 	// enforce that SetFields cannot be called once
 	// t's width has been calculated.
 	if t.WidthCalculated() {
-		Fatalf("SetFields of %v: width previously calculated", t)
+		base.Fatalf("SetFields of %v: width previously calculated", t)
 	}
 	t.wantEtype(TSTRUCT)
 	for _, f := range fields {
@@ -1223,7 +1223,7 @@ var unsignedEType = [...]Kind{
 // ToUnsigned returns the unsigned equivalent of integer type t.
 func (t *Type) ToUnsigned() *Type {
 	if !t.IsInteger() {
-		Fatalf("unsignedType(%v)", t)
+		base.Fatalf("unsignedType(%v)", t)
 	}
 	return Types[unsignedEType[t.kind]]
 }
@@ -1385,7 +1385,7 @@ func (t *Type) NumComponents(countBlank componentsIncludeBlankFields) int64 {
 	switch t.kind {
 	case TSTRUCT:
 		if t.IsFuncArgStruct() {
-			Fatalf("NumComponents func arg struct")
+			base.Fatalf("NumComponents func arg struct")
 		}
 		var n int64
 		for _, f := range t.FieldSlice() {
@@ -1408,7 +1408,7 @@ func (t *Type) SoleComponent() *Type {
 	switch t.kind {
 	case TSTRUCT:
 		if t.IsFuncArgStruct() {
-			Fatalf("SoleComponent func arg struct")
+			base.Fatalf("SoleComponent func arg struct")
 		}
 		if t.NumFields() != 1 {
 			return nil

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

@@ -15,51 +15,47 @@ const BADWIDTH = -1000000000
 // They are here to break import cycles.
 // TODO(gri) eliminate these dependencies.
 var (
-	Widthptr    int
+	Widthptr        int
-	Dowidth     func(*Type)
+	Dowidth         func(*Type)
-	Fatalf      func(string, ...interface{})
+	SymString       func(*Sym) string
-	Sconv       func(*Sym, int, int) string       // orig: func sconv(s *Sym, flag FmtFlag, mode fmtMode) string
+	TypeString      func(*Type) string
-	Tconv       func(*Type, int, int) string      // orig: func tconv(t *Type, flag FmtFlag, mode fmtMode) string
+	TypeShortString func(*Type) string
-	FormatSym   func(*Sym, fmt.State, rune, int)  // orig: func symFormat(sym *Sym, s fmt.State, verb rune, mode fmtMode)
+	TypeLongString  func(*Type) string
-	FormatType  func(*Type, fmt.State, rune, int) // orig: func typeFormat(t *Type, s fmt.State, verb rune, mode fmtMode)
+	FormatSym       func(*Sym, fmt.State, rune)
-	TypeLinkSym func(*Type) *obj.LSym
+	FormatType      func(*Type, fmt.State, rune)
-	Ctxt        *obj.Link
+	TypeLinkSym     func(*Type) *obj.LSym
-
-	FmtLeft     int
-	FmtUnsigned int
-	FErr        int
 )
 
 func (s *Sym) String() string {
-	return Sconv(s, 0, FErr)
+	return SymString(s)
 }
 
 func (sym *Sym) Format(s fmt.State, verb rune) {
-	FormatSym(sym, s, verb, FErr)
+	FormatSym(sym, s, verb)
 }
 
 func (t *Type) String() string {
-	// The implementation of tconv (including typefmt and fldconv)
+	// The implementation
 	// must handle recursive types correctly.
-	return Tconv(t, 0, FErr)
+	return TypeString(t)
 }
 
 // ShortString generates a short description of t.
 // It is used in autogenerated method names, reflection,
 // and itab names.
 func (t *Type) ShortString() string {
-	return Tconv(t, FmtLeft, FErr)
+	return TypeShortString(t)
 }
 
 // LongString generates a complete description of t.
 // It is useful for reflection,
 // or when a unique fingerprint or hash of a type is required.
 func (t *Type) LongString() string {
-	return Tconv(t, FmtLeft|FmtUnsigned, FErr)
+	return TypeLongString(t)
 }
 
 func (t *Type) Format(s fmt.State, verb rune) {
-	FormatType(t, s, verb, FErr)
+	FormatType(t, s, verb)
 }
 
 type bitset8 uint8