cmd/compile: move types init code into package types

This moves the package types setup code from package typecheck into
package types itself. This is a prereq for making types.Type more
opaque, because some unit tests depend on being able to init the basic
universal types.

A few notable details of this CL:

1. Creating the builtin types requires being able to create the
ir.Name/ir.OTYPE that represents it, but package types can't depend on
package ir. So we add a callback function to handle creating the
ir.Name.

2. This CL moves ir.Pkgs.Unsafe to types.UnsafePkg. Package unsafe is
part of the language, not like the other ir.Pkgs packages that are
purely implementation details.

3. This CL also moves typecheck.FakeRecv to types.FakeRecv, addressing
an outstanding TODO.

Change-Id: I64de04ce82fbcd1bb59f547e2eea3cda52d89429
Reviewed-on: https://go-review.googlesource.com/c/go/+/345474
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

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

@@ -84,7 +84,7 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 	types.BuiltinPkg.Prefix = "go.builtin"            // not go%2ebuiltin
 
 	// pseudo-package, accessed by import "unsafe"
-	ir.Pkgs.Unsafe = types.NewPkg("unsafe", "unsafe")
+	types.UnsafePkg = types.NewPkg("unsafe", "unsafe")
 
 	// Pseudo-package that contains the compiler's builtin
 	// declarations for package runtime. These are declared in a

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

@@ -68,5 +68,4 @@ var Pkgs struct {
 	Go      *types.Pkg
 	Itab    *types.Pkg
 	Runtime *types.Pkg
-	Unsafe  *types.Pkg
 }

src/cmd/compile/internal/noder/import.go

@@ -198,7 +198,7 @@ func importfile(decl *syntax.ImportDecl) *types.Pkg {
 		return nil
 	}
 
-	if pkg != ir.Pkgs.Unsafe && pkg.Height >= myheight {
+	if pkg != types.UnsafePkg && pkg.Height >= myheight {
 		myheight = pkg.Height + 1
 	}
 	return pkg
@@ -231,7 +231,7 @@ func readImportFile(path string, target *ir.Package, check *types2.Checker, pack
 	}
 
 	if path == "unsafe" {
-		pkg1, pkg2 = ir.Pkgs.Unsafe, types2.Unsafe
+		pkg1, pkg2 = types.UnsafePkg, types2.Unsafe
 
 		// TODO(mdempsky): Investigate if this actually matters. Why would
 		// the linker or runtime care whether a package imported unsafe?

src/cmd/compile/internal/noder/noder.go

@@ -384,7 +384,7 @@ func (p *noder) importDecl(imp *syntax.ImportDecl) {
 		return
 	}
 
-	if ipkg == ir.Pkgs.Unsafe {
+	if ipkg == types.UnsafePkg {
 		p.importedUnsafe = true
 	}
 	if ipkg.Path == "embed" {

src/cmd/compile/internal/noder/reader.go

@@ -428,7 +428,7 @@ func (r *reader) interfaceType() *types.Type {
 		pos := r.pos()
 		pkg, sym := r.selector()
 		tpkg = pkg
-		mtyp := r.signature(pkg, typecheck.FakeRecv())
+		mtyp := r.signature(pkg, types.FakeRecv())
 		methods[i] = types.NewField(pos, sym, mtyp)
 	}
 	for i := range embeddeds {
@@ -540,7 +540,7 @@ func (pr *pkgReader) objIdx(idx int, implicits, explicits []*types.Type) ir.Node
 	if tag == objStub {
 		assert(!sym.IsBlank())
 		switch sym.Pkg {
-		case types.BuiltinPkg, ir.Pkgs.Unsafe:
+		case types.BuiltinPkg, types.UnsafePkg:
 			return sym.Def.(ir.Node)
 		}
 		if pri, ok := objReader[sym]; ok {

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

@@ -22,7 +22,7 @@ func (g *irgen) pkg(pkg *types2.Package) *types.Pkg {
 	case g.self:
 		return types.LocalPkg
 	case types2.Unsafe:
-		return ir.Pkgs.Unsafe
+		return types.UnsafePkg
 	}
 	return types.NewPkg(pkg.Path(), pkg.Name())
 }
@@ -206,7 +206,7 @@ func (g *irgen) typ0(typ types2.Type) *types.Type {
 		methods := make([]*types.Field, typ.NumExplicitMethods())
 		for i := range methods {
 			m := typ.ExplicitMethod(i)
-			mtyp := g.signature(typecheck.FakeRecv(), m.Type().(*types2.Signature))
+			mtyp := g.signature(types.FakeRecv(), m.Type().(*types2.Signature))
 			methods[i] = types.NewField(g.pos(m), g.selector(m), mtyp)
 		}
 

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

@@ -1726,7 +1726,7 @@ func NeedEmit(typ *types.Type) bool {
 		// Local defined type; our responsibility.
 		return true
 
-	case base.Ctxt.Pkgpath == "runtime" && (sym.Pkg == types.BuiltinPkg || sym.Pkg == ir.Pkgs.Unsafe):
+	case base.Ctxt.Pkgpath == "runtime" && (sym.Pkg == types.BuiltinPkg || sym.Pkg == types.UnsafePkg):
 		// Package runtime is responsible for including code for builtin
 		// types (predeclared and package unsafe).
 		return true

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

@@ -314,13 +314,6 @@ func checkembeddedtype(t *types.Type) {
 	}
 }
 
-// TODO(mdempsky): Move to package types.
-func FakeRecv() *types.Field {
-	return types.NewField(src.NoXPos, nil, types.FakeRecvType())
-}
-
-var fakeRecvField = FakeRecv
-
 var funcStack []funcStackEnt // stack of previous values of ir.CurFunc/DeclContext
 
 type funcStackEnt struct {

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

@@ -430,7 +430,7 @@ func (p *iexporter) pushDecl(n *ir.Name) {
 	}
 
 	// Don't export predeclared declarations.
-	if n.Sym().Pkg == types.BuiltinPkg || n.Sym().Pkg == ir.Pkgs.Unsafe {
+	if n.Sym().Pkg == types.BuiltinPkg || n.Sym().Pkg == types.UnsafePkg {
 		return
 	}
 
@@ -905,7 +905,7 @@ func (w *exportWriter) doTyp(t *types.Type) {
 	// type orderedAbs[T any] T
 	if t.IsTypeParam() && t.Underlying() == t {
 		assert(base.Flag.G > 0)
-		if s.Pkg == types.BuiltinPkg || s.Pkg == ir.Pkgs.Unsafe {
+		if s.Pkg == types.BuiltinPkg || s.Pkg == types.UnsafePkg {
 			base.Fatalf("builtin type missing from typIndex: %v", t)
 		}
 		// Write out the first use of a type param as a qualified ident.
@@ -916,7 +916,7 @@ func (w *exportWriter) doTyp(t *types.Type) {
 	}
 
 	if s != nil {
-		if s.Pkg == types.BuiltinPkg || s.Pkg == ir.Pkgs.Unsafe {
+		if s.Pkg == types.BuiltinPkg || s.Pkg == types.UnsafePkg {
 			base.Fatalf("builtin type missing from typIndex: %v", t)
 		}
 

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

@@ -607,7 +607,7 @@ func (r *importReader) exoticType() *types.Type {
 	case exoticTypeRecv:
 		var rcvr *types.Field
 		if r.bool() { // isFakeRecv
-			rcvr = fakeRecvField()
+			rcvr = types.FakeRecv()
 		} else {
 			rcvr = r.exoticParam()
 		}
@@ -793,7 +793,7 @@ func (r *importReader) typ1() *types.Type {
 		for i := range methods {
 			pos := r.pos()
 			sym := r.selector()
-			typ := r.signature(fakeRecvField(), nil)
+			typ := r.signature(types.FakeRecv(), nil)
 
 			methods[i] = types.NewField(pos, sym, typ)
 		}

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

@@ -29,37 +29,6 @@ var (
 	okforarith [types.NTYPE]bool
 )
 
-var basicTypes = [...]struct {
-	name  string
-	etype types.Kind
-}{
-	{"int8", types.TINT8},
-	{"int16", types.TINT16},
-	{"int32", types.TINT32},
-	{"int64", types.TINT64},
-	{"uint8", types.TUINT8},
-	{"uint16", types.TUINT16},
-	{"uint32", types.TUINT32},
-	{"uint64", types.TUINT64},
-	{"float32", types.TFLOAT32},
-	{"float64", types.TFLOAT64},
-	{"complex64", types.TCOMPLEX64},
-	{"complex128", types.TCOMPLEX128},
-	{"bool", types.TBOOL},
-	{"string", types.TSTRING},
-}
-
-var typedefs = [...]struct {
-	name     string
-	etype    types.Kind
-	sameas32 types.Kind
-	sameas64 types.Kind
-}{
-	{"int", types.TINT, types.TINT32, types.TINT64},
-	{"uint", types.TUINT, types.TUINT32, types.TUINT64},
-	{"uintptr", types.TUINTPTR, types.TUINT32, types.TUINT64},
-}
-
 var builtinFuncs = [...]struct {
 	name string
 	op   ir.Op
@@ -94,86 +63,12 @@ var unsafeFuncs = [...]struct {
 
 // InitUniverse initializes the universe block.
 func InitUniverse() {
-	if types.PtrSize == 0 {
+	types.InitTypes(func(sym *types.Sym, typ *types.Type) types.Object {
-		base.Fatalf("typeinit before betypeinit")
-	}
-
-	types.SlicePtrOffset = 0
-	types.SliceLenOffset = types.Rnd(types.SlicePtrOffset+int64(types.PtrSize), int64(types.PtrSize))
-	types.SliceCapOffset = types.Rnd(types.SliceLenOffset+int64(types.PtrSize), int64(types.PtrSize))
-	types.SliceSize = types.Rnd(types.SliceCapOffset+int64(types.PtrSize), int64(types.PtrSize))
-
-	// string is same as slice wo the cap
-	types.StringSize = types.Rnd(types.SliceLenOffset+int64(types.PtrSize), int64(types.PtrSize))
-
-	for et := types.Kind(0); et < types.NTYPE; et++ {
-		types.SimType[et] = et
-	}
-
-	types.Types[types.TANY] = types.New(types.TANY)
-	types.Types[types.TINTER] = types.NewInterface(types.LocalPkg, nil)
-
-	defBasic := func(kind types.Kind, pkg *types.Pkg, name string) *types.Type {
-		sym := pkg.Lookup(name)
 		n := ir.NewDeclNameAt(src.NoXPos, ir.OTYPE, sym)
-		t := types.NewBasic(kind, n)
+		n.SetType(typ)
-		n.SetType(t)
 		sym.Def = n
-		if kind != types.TANY {
+		return n
-			types.CalcSize(t)
+	})
-		}
-		return t
-	}
-
-	for _, s := range &basicTypes {
-		types.Types[s.etype] = defBasic(s.etype, types.BuiltinPkg, s.name)
-	}
-
-	for _, s := range &typedefs {
-		sameas := s.sameas32
-		if types.PtrSize == 8 {
-			sameas = s.sameas64
-		}
-		types.SimType[s.etype] = sameas
-
-		types.Types[s.etype] = defBasic(s.etype, types.BuiltinPkg, s.name)
-	}
-
-	// We create separate byte and rune types for better error messages
-	// rather than just creating type alias *types.Sym's for the uint8 and
-	// int32 types. Hence, (bytetype|runtype).Sym.isAlias() is false.
-	// TODO(gri) Should we get rid of this special case (at the cost
-	// of less informative error messages involving bytes and runes)?
-	// (Alternatively, we could introduce an OTALIAS node representing
-	// type aliases, albeit at the cost of having to deal with it everywhere).
-	types.ByteType = defBasic(types.TUINT8, types.BuiltinPkg, "byte")
-	types.RuneType = defBasic(types.TINT32, types.BuiltinPkg, "rune")
-
-	// error type
-	s := types.BuiltinPkg.Lookup("error")
-	n := ir.NewDeclNameAt(src.NoXPos, ir.OTYPE, s)
-	types.ErrorType = types.NewNamed(n)
-	types.ErrorType.SetUnderlying(makeErrorInterface())
-	n.SetType(types.ErrorType)
-	s.Def = n
-	types.CalcSize(types.ErrorType)
-
-	// comparable type (interface)
-	s = types.BuiltinPkg.Lookup("comparable")
-	n = ir.NewDeclNameAt(src.NoXPos, ir.OTYPE, s)
-	types.ComparableType = types.NewNamed(n)
-	types.ComparableType.SetUnderlying(makeComparableInterface())
-	n.SetType(types.ComparableType)
-	s.Def = n
-	types.CalcSize(types.ComparableType)
-
-	types.Types[types.TUNSAFEPTR] = defBasic(types.TUNSAFEPTR, ir.Pkgs.Unsafe, "Pointer")
-
-	// simple aliases
-	types.SimType[types.TMAP] = types.TPTR
-	types.SimType[types.TCHAN] = types.TPTR
-	types.SimType[types.TFUNC] = types.TPTR
-	types.SimType[types.TUNSAFEPTR] = types.TPTR
 
 	for _, s := range &builtinFuncs {
 		s2 := types.BuiltinPkg.Lookup(s.name)
@@ -183,13 +78,13 @@ func InitUniverse() {
 	}
 
 	for _, s := range &unsafeFuncs {
-		s2 := ir.Pkgs.Unsafe.Lookup(s.name)
+		s2 := types.UnsafePkg.Lookup(s.name)
 		def := NewName(s2)
 		def.BuiltinOp = s.op
 		s2.Def = def
 	}
 
-	s = types.BuiltinPkg.Lookup("true")
+	s := types.BuiltinPkg.Lookup("true")
 	s.Def = ir.NewConstAt(src.NoXPos, s, types.UntypedBool, constant.MakeBool(true))
 
 	s = types.BuiltinPkg.Lookup("false")
@@ -219,19 +114,6 @@ func InitUniverse() {
 	s = types.BuiltinPkg.Lookup("iota")
 	s.Def = ir.NewIota(base.Pos, s)
 
-	for et := types.TINT8; et <= types.TUINT64; et++ {
-		types.IsInt[et] = true
-	}
-	types.IsInt[types.TINT] = true
-	types.IsInt[types.TUINT] = true
-	types.IsInt[types.TUINTPTR] = true
-
-	types.IsFloat[types.TFLOAT32] = true
-	types.IsFloat[types.TFLOAT64] = true
-
-	types.IsComplex[types.TCOMPLEX64] = true
-	types.IsComplex[types.TCOMPLEX128] = true
-
 	// initialize okfor
 	for et := types.Kind(0); et < types.NTYPE; et++ {
 		if types.IsInt[et] || et == types.TIDEAL {
@@ -331,20 +213,6 @@ func InitUniverse() {
 	okfor[ir.OLEN] = okforlen[:]
 }
 
-func makeErrorInterface() *types.Type {
-	sig := types.NewSignature(types.NoPkg, fakeRecvField(), nil, nil, []*types.Field{
-		types.NewField(src.NoXPos, nil, types.Types[types.TSTRING]),
-	})
-	method := types.NewField(src.NoXPos, Lookup("Error"), sig)
-	return types.NewInterface(types.NoPkg, []*types.Field{method})
-}
-
-func makeComparableInterface() *types.Type {
-	sig := types.NewSignature(types.NoPkg, fakeRecvField(), nil, nil, nil)
-	method := types.NewField(src.NoXPos, Lookup("=="), sig)
-	return types.NewInterface(types.NoPkg, []*types.Field{method})
-}
-
 // DeclareUniverse makes the universe block visible within the current package.
 func DeclareUniverse() {
 	// Operationally, this is similar to a dot import of builtinpkg, except

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

@@ -23,6 +23,9 @@ var BuiltinPkg *Pkg
 // LocalPkg is the package being compiled.
 var LocalPkg *Pkg
 
+// UnsafePkg is package unsafe.
+var UnsafePkg *Pkg
+
 // BlankSym is the blank (_) symbol.
 var BlankSym *Sym
 

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

@@ -1738,6 +1738,10 @@ func FakeRecvType() *Type {
 	return recvType
 }
 
+func FakeRecv() *Field {
+	return NewField(src.NoXPos, nil, FakeRecvType())
+}
+
 var (
 	// TSSA types. HasPointers assumes these are pointer-free.
 	TypeInvalid   = newSSA("invalid")

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

@@ -0,0 +1,144 @@
+// Copyright 2009 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 types
+
+import (
+	"cmd/compile/internal/base"
+	"cmd/internal/src"
+)
+
+var basicTypes = [...]struct {
+	name  string
+	etype Kind
+}{
+	{"int8", TINT8},
+	{"int16", TINT16},
+	{"int32", TINT32},
+	{"int64", TINT64},
+	{"uint8", TUINT8},
+	{"uint16", TUINT16},
+	{"uint32", TUINT32},
+	{"uint64", TUINT64},
+	{"float32", TFLOAT32},
+	{"float64", TFLOAT64},
+	{"complex64", TCOMPLEX64},
+	{"complex128", TCOMPLEX128},
+	{"bool", TBOOL},
+	{"string", TSTRING},
+}
+
+var typedefs = [...]struct {
+	name     string
+	etype    Kind
+	sameas32 Kind
+	sameas64 Kind
+}{
+	{"int", TINT, TINT32, TINT64},
+	{"uint", TUINT, TUINT32, TUINT64},
+	{"uintptr", TUINTPTR, TUINT32, TUINT64},
+}
+
+func InitTypes(defTypeName func(sym *Sym, typ *Type) Object) {
+	if PtrSize == 0 {
+		base.Fatalf("typeinit before betypeinit")
+	}
+
+	SlicePtrOffset = 0
+	SliceLenOffset = Rnd(SlicePtrOffset+int64(PtrSize), int64(PtrSize))
+	SliceCapOffset = Rnd(SliceLenOffset+int64(PtrSize), int64(PtrSize))
+	SliceSize = Rnd(SliceCapOffset+int64(PtrSize), int64(PtrSize))
+
+	// string is same as slice wo the cap
+	StringSize = Rnd(SliceLenOffset+int64(PtrSize), int64(PtrSize))
+
+	for et := Kind(0); et < NTYPE; et++ {
+		SimType[et] = et
+	}
+
+	Types[TANY] = New(TANY)
+	Types[TINTER] = NewInterface(LocalPkg, nil)
+
+	defBasic := func(kind Kind, pkg *Pkg, name string) *Type {
+		typ := New(kind)
+		obj := defTypeName(pkg.Lookup(name), typ)
+		typ.sym = obj.Sym()
+		typ.nod = obj
+		if kind != TANY {
+			CheckSize(typ)
+		}
+		return typ
+	}
+
+	for _, s := range &basicTypes {
+		Types[s.etype] = defBasic(s.etype, BuiltinPkg, s.name)
+	}
+
+	for _, s := range &typedefs {
+		sameas := s.sameas32
+		if PtrSize == 8 {
+			sameas = s.sameas64
+		}
+		SimType[s.etype] = sameas
+
+		Types[s.etype] = defBasic(s.etype, BuiltinPkg, s.name)
+	}
+
+	// We create separate byte and rune types for better error messages
+	// rather than just creating type alias *Sym's for the uint8 and
+	// int32  Hence, (bytetype|runtype).Sym.isAlias() is false.
+	// TODO(gri) Should we get rid of this special case (at the cost
+	// of less informative error messages involving bytes and runes)?
+	// (Alternatively, we could introduce an OTALIAS node representing
+	// type aliases, albeit at the cost of having to deal with it everywhere).
+	ByteType = defBasic(TUINT8, BuiltinPkg, "byte")
+	RuneType = defBasic(TINT32, BuiltinPkg, "rune")
+
+	// error type
+	DeferCheckSize()
+	ErrorType = defBasic(TFORW, BuiltinPkg, "error")
+	ErrorType.SetUnderlying(makeErrorInterface())
+	ResumeCheckSize()
+
+	// comparable type (interface)
+	DeferCheckSize()
+	ComparableType = defBasic(TFORW, BuiltinPkg, "comparable")
+	ComparableType.SetUnderlying(makeComparableInterface())
+	ResumeCheckSize()
+
+	Types[TUNSAFEPTR] = defBasic(TUNSAFEPTR, UnsafePkg, "Pointer")
+
+	// simple aliases
+	SimType[TMAP] = TPTR
+	SimType[TCHAN] = TPTR
+	SimType[TFUNC] = TPTR
+	SimType[TUNSAFEPTR] = TPTR
+
+	for et := TINT8; et <= TUINT64; et++ {
+		IsInt[et] = true
+	}
+	IsInt[TINT] = true
+	IsInt[TUINT] = true
+	IsInt[TUINTPTR] = true
+
+	IsFloat[TFLOAT32] = true
+	IsFloat[TFLOAT64] = true
+
+	IsComplex[TCOMPLEX64] = true
+	IsComplex[TCOMPLEX128] = true
+}
+
+func makeErrorInterface() *Type {
+	sig := NewSignature(NoPkg, FakeRecv(), nil, nil, []*Field{
+		NewField(src.NoXPos, nil, Types[TSTRING]),
+	})
+	method := NewField(src.NoXPos, LocalPkg.Lookup("Error"), sig)
+	return NewInterface(NoPkg, []*Field{method})
+}
+
+func makeComparableInterface() *Type {
+	sig := NewSignature(NoPkg, FakeRecv(), nil, nil, nil)
+	method := NewField(src.NoXPos, LocalPkg.Lookup("=="), sig)
+	return NewInterface(NoPkg, []*Field{method})
+}