[dev.regabi] cmd/compile: separate noder more cleanly

Separate embed, cgo pragmas, and Main trackScopes variable
from noder more cleanly.

This lets us split embed and noder into new packages.
It also assumes that the local embedded variables will be
removed and deletes them now for simplicity.

Change-Id: I9638bcc2c5f0e76440de056c6285b6aa2f73a00d
Reviewed-on: https://go-review.googlesource.com/c/go/+/279299
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/gc/embed.go

@@ -24,8 +24,6 @@ const (
 	embedFiles
 )
 
-var numLocalEmbed int
-
 func varEmbed(p *noder, names []ir.Node, typ ir.Ntype, exprs []ir.Node, embeds []PragmaEmbed) (newExprs []ir.Node) {
 	haveEmbed := false
 	for _, decl := range p.file.DeclList {
@@ -63,25 +61,39 @@ func varEmbed(p *noder, names []ir.Node, typ ir.Ntype, exprs []ir.Node, embeds [
 		p.errorAt(pos, "go:embed cannot apply to var without type")
 		return exprs
 	}
-
+	if dclcontext != ir.PEXTERN {
-	kind := embedKindApprox(typ)
+		p.errorAt(pos, "go:embed cannot apply to var inside func")
-	if kind == embedUnknown {
-		p.errorAt(pos, "go:embed cannot apply to var of type %v", typ)
 		return exprs
 	}
 
+	v := names[0].(*ir.Name)
+	Target.Embeds = append(Target.Embeds, v)
+	v.Embed = new([]ir.Embed)
+	for _, e := range embeds {
+		*v.Embed = append(*v.Embed, ir.Embed{Pos: p.makeXPos(e.Pos), Patterns: e.Patterns})
+	}
+	return exprs
+}
+
+func embedFileList(v *ir.Name) []string {
+	kind := embedKind(v.Type())
+	if kind == embedUnknown {
+		base.ErrorfAt(v.Pos(), "go:embed cannot apply to var of type %v", v.Type())
+		return nil
+	}
+
 	// Build list of files to store.
 	have := make(map[string]bool)
 	var list []string
-	for _, e := range embeds {
+	for _, e := range *v.Embed {
 		for _, pattern := range e.Patterns {
 			files, ok := base.Flag.Cfg.Embed.Patterns[pattern]
 			if !ok {
-				p.errorAt(e.Pos, "invalid go:embed: build system did not map pattern: %s", pattern)
+				base.ErrorfAt(e.Pos, "invalid go:embed: build system did not map pattern: %s", pattern)
 			}
 			for _, file := range files {
 				if base.Flag.Cfg.Embed.Files[file] == "" {
-					p.errorAt(e.Pos, "invalid go:embed: build system did not map file: %s", file)
+					base.ErrorfAt(e.Pos, "invalid go:embed: build system did not map file: %s", file)
 					continue
 				}
 				if !have[file] {
@@ -103,25 +115,12 @@ func varEmbed(p *noder, names []ir.Node, typ ir.Ntype, exprs []ir.Node, embeds [
 
 	if kind == embedString || kind == embedBytes {
 		if len(list) > 1 {
-			p.errorAt(pos, "invalid go:embed: multiple files for type %v", typ)
+			base.ErrorfAt(v.Pos(), "invalid go:embed: multiple files for type %v", v.Type())
-			return exprs
+			return nil
 		}
 	}
 
-	v := names[0].(*ir.Name)
+	return list
-	if dclcontext != ir.PEXTERN {
-		numLocalEmbed++
-		v = ir.NewNameAt(v.Pos(), lookupN("embed.", numLocalEmbed))
-		v.Sym().Def = v
-		v.Name().Ntype = typ
-		v.SetClass(ir.PEXTERN)
-		Target.Externs = append(Target.Externs, v)
-		exprs = []ir.Node{v}
-	}
-
-	v.Name().SetEmbedFiles(list)
-	Target.Embeds = append(Target.Embeds, v)
-	return exprs
 }
 
 // embedKindApprox determines the kind of embedding variable, approximately.
@@ -192,8 +191,8 @@ func dumpembeds() {
 
 // initEmbed emits the init data for a //go:embed variable,
 // which is either a string, a []byte, or an embed.FS.
-func initEmbed(v ir.Node) {
+func initEmbed(v *ir.Name) {
-	files := v.Name().EmbedFiles()
+	files := embedFileList(v)
 	switch kind := embedKind(v.Type()); kind {
 	case embedUnknown:
 		base.ErrorfAt(v.Pos(), "go:embed cannot apply to var of type %v", v.Type())

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

@@ -116,13 +116,14 @@ var (
 	okforadd   [types.NTYPE]bool
 	okforand   [types.NTYPE]bool
 	okfornone  [types.NTYPE]bool
-	okforcmp   [types.NTYPE]bool
 	okforbool  [types.NTYPE]bool
 	okforcap   [types.NTYPE]bool
 	okforlen   [types.NTYPE]bool
 	okforarith [types.NTYPE]bool
 )
 
+var okforcmp [types.NTYPE]bool
+
 var (
 	okfor [ir.OEND][]bool
 	iscmp [ir.OEND]bool
@@ -149,9 +150,6 @@ var typecheckok bool
 // when the race detector is enabled.
 var instrumenting bool
 
-// Whether we are tracking lexical scopes for DWARF.
-var trackScopes bool
-
 var nodfp *ir.Name
 
 var autogeneratedPos src.XPos

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

@@ -205,8 +205,6 @@ func Main(archInit func(*Arch)) {
 		}
 	}
 
-	trackScopes = base.Flag.Dwarf
-
 	Widthptr = thearch.LinkArch.PtrSize
 	Widthreg = thearch.LinkArch.RegSize
 
@@ -226,6 +224,7 @@ func Main(archInit func(*Arch)) {
 
 	timings.Start("fe", "parse")
 	lines := parseFiles(flag.Args())
+	cgoSymABIs()
 	timings.Stop()
 	timings.AddEvent(int64(lines), "lines")
 
@@ -477,6 +476,20 @@ func Main(archInit func(*Arch)) {
 	}
 }
 
+func cgoSymABIs() {
+	// The linker expects an ABI0 wrapper for all cgo-exported
+	// functions.
+	for _, prag := range Target.CgoPragmas {
+		switch prag[0] {
+		case "cgo_export_static", "cgo_export_dynamic":
+			if symabiRefs == nil {
+				symabiRefs = make(map[string]obj.ABI)
+			}
+			symabiRefs[prag[1]] = obj.ABI0
+		}
+	}
+}
+
 // numNonClosures returns the number of functions in list which are not closures.
 func numNonClosures(list []*ir.Func) int {
 	count := 0

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

@@ -20,7 +20,6 @@ import (
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/syntax"
 	"cmd/compile/internal/types"
-	"cmd/internal/obj"
 	"cmd/internal/objabi"
 	"cmd/internal/src"
 )
@@ -36,8 +35,9 @@ func parseFiles(filenames []string) uint {
 
 	for _, filename := range filenames {
 		p := &noder{
-			basemap: make(map[*syntax.PosBase]*src.PosBase),
+			basemap:     make(map[*syntax.PosBase]*src.PosBase),
-			err:     make(chan syntax.Error),
+			err:         make(chan syntax.Error),
+			trackScopes: base.Flag.Dwarf,
 		}
 		noders = append(noders, p)
 
@@ -151,7 +151,8 @@ type noder struct {
 
 	// scopeVars is a stack tracking the number of variables declared in the
 	// current function at the moment each open scope was opened.
-	scopeVars []int
+	trackScopes bool
+	scopeVars   []int
 
 	lastCloseScopePos syntax.Pos
 }
@@ -179,7 +180,7 @@ func (p *noder) funcBody(fn *ir.Func, block *syntax.BlockStmt) {
 func (p *noder) openScope(pos syntax.Pos) {
 	types.Markdcl()
 
-	if trackScopes {
+	if p.trackScopes {
 		Curfn.Parents = append(Curfn.Parents, p.scope)
 		p.scopeVars = append(p.scopeVars, len(Curfn.Dcl))
 		p.scope = ir.ScopeID(len(Curfn.Parents))
@@ -192,7 +193,7 @@ func (p *noder) closeScope(pos syntax.Pos) {
 	p.lastCloseScopePos = pos
 	types.Popdcl()
 
-	if trackScopes {
+	if p.trackScopes {
 		scopeVars := p.scopeVars[len(p.scopeVars)-1]
 		p.scopeVars = p.scopeVars[:len(p.scopeVars)-1]
 		if scopeVars == len(Curfn.Dcl) {
@@ -284,19 +285,6 @@ func (p *noder) processPragmas() {
 		}
 		n.Sym().Linkname = l.remote
 	}
-
-	// The linker expects an ABI0 wrapper for all cgo-exported
-	// functions.
-	for _, prag := range p.pragcgobuf {
-		switch prag[0] {
-		case "cgo_export_static", "cgo_export_dynamic":
-			if symabiRefs == nil {
-				symabiRefs = make(map[string]obj.ABI)
-			}
-			symabiRefs[prag[1]] = obj.ABI0
-		}
-	}
-
 	Target.CgoPragmas = append(Target.CgoPragmas, p.pragcgobuf...)
 }
 

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

@@ -34,16 +34,16 @@ func (*Ident) CanBeNtype() {}
 // Name holds Node fields used only by named nodes (ONAME, OTYPE, some OLITERAL).
 type Name struct {
 	miniExpr
-	BuiltinOp  Op    // uint8
+	BuiltinOp Op    // uint8
-	Class_     Class // uint8
+	Class_    Class // uint8
-	flags      bitset16
+	flags     bitset16
-	pragma     PragmaFlag // int16
+	pragma    PragmaFlag // int16
-	sym        *types.Sym
+	sym       *types.Sym
-	fn         *Func
+	fn        *Func
-	Offset_    int64
+	Offset_   int64
-	val        constant.Value
+	val       constant.Value
-	orig       Node
+	orig      Node
-	embedFiles *[]string // list of embedded files, for ONAME var
+	Embed     *[]Embed // list of embedded files, for ONAME var
 
 	PkgName *PkgName // real package for import . names
 	// For a local variable (not param) or extern, the initializing assignment (OAS or OAS2).
@@ -139,14 +139,14 @@ type Name struct {
 	Outer     *Name
 }
 
+func (n *Name) isExpr() {}
+
 // CloneName makes a cloned copy of the name.
 // It's not ir.Copy(n) because in general that operation is a mistake on names,
 // which uniquely identify variables.
 // Callers must use n.CloneName to make clear they intend to create a separate name.
 func (n *Name) CloneName() *Name { c := *n; return &c }
 
-func (n *Name) isExpr() {}
-
 // NewNameAt returns a new ONAME Node associated with symbol s at position pos.
 // The caller is responsible for setting Curfn.
 func NewNameAt(pos src.XPos, sym *types.Sym) *Name {
@@ -231,27 +231,6 @@ func (n *Name) Alias() bool { return n.flags&nameAlias != 0 }
 // SetAlias sets whether p, which must be for an OTYPE, is a type alias.
 func (n *Name) SetAlias(alias bool) { n.flags.set(nameAlias, alias) }
 
-// EmbedFiles returns the list of embedded files for p,
-// which must be for an ONAME var.
-func (n *Name) EmbedFiles() []string {
-	if n.embedFiles == nil {
-		return nil
-	}
-	return *n.embedFiles
-}
-
-// SetEmbedFiles sets the list of embedded files for p,
-// which must be for an ONAME var.
-func (n *Name) SetEmbedFiles(list []string) {
-	if n.embedFiles == nil && list == nil {
-		return
-	}
-	if n.embedFiles == nil {
-		n.embedFiles = new([]string)
-	}
-	*n.embedFiles = list
-}
-
 const (
 	nameCaptured = 1 << iota // is the variable captured by a closure
 	nameReadonly
@@ -389,6 +368,11 @@ const (
 	_ = uint((1 << 3) - iota) // static assert for iota <= (1 << 3)
 )
 
+type Embed struct {
+	Pos      src.XPos
+	Patterns []string
+}
+
 // A Pack is an identifier referring to an imported package.
 type PkgName struct {
 	miniNode

src/embed/internal/embedtest/embed_test.go

@@ -73,24 +73,14 @@ func TestGlobal(t *testing.T) {
 	testString(t, string(glass), "glass", "I can eat glass and it doesn't hurt me.\n")
 }
 
-func TestLocal(t *testing.T) {
+//go:embed testdata
-	//go:embed testdata/k*.txt
+var dir embed.FS
-	var local embed.FS
-	testFiles(t, local, "testdata/ken.txt", "If a program is too slow, it must have a loop.\n")
 
-	//go:embed testdata/k*.txt
+//go:embed testdata/*
-	var s string
+var star embed.FS
-	testString(t, s, "local variable s", "If a program is too slow, it must have a loop.\n")
-
-	//go:embed testdata/h*.txt
-	var b []byte
-	testString(t, string(b), "local variable b", "hello, world\n")
-}
 
 func TestDir(t *testing.T) {
-	//go:embed testdata
+	all := dir
-	var all embed.FS
-
 	testFiles(t, all, "testdata/hello.txt", "hello, world\n")
 	testFiles(t, all, "testdata/i/i18n.txt", "internationalization\n")
 	testFiles(t, all, "testdata/i/j/k/k8s.txt", "kubernetes\n")
@@ -103,12 +93,6 @@ func TestDir(t *testing.T) {
 }
 
 func TestHidden(t *testing.T) {
-	//go:embed testdata
-	var dir embed.FS
-
-	//go:embed testdata/*
-	var star embed.FS
-
 	t.Logf("//go:embed testdata")
 
 	testDir(t, dir, "testdata",

src/embed/internal/embedtest/embedx_test.go

@@ -90,17 +90,3 @@ func TestXGlobal(t *testing.T) {
 	}
 	bbig[0] = old
 }
-
-func TestXLocal(t *testing.T) {
-	//go:embed testdata/*o.txt
-	var local embed.FS
-	testFiles(t, local, "testdata/hello.txt", "hello, world\n")
-
-	//go:embed testdata/k*.txt
-	var s string
-	testString(t, s, "local variable s", "If a program is too slow, it must have a loop.\n")
-
-	//go:embed testdata/h*.txt
-	var b []byte
-	testString(t, string(b), "local variable b", "hello, world\n")
-}