[dev.regabi] cmd/compile: prepare for package ir

The next CL will introduce a package ir to hold the IR definitions.
This CL adjusts a few names and makes a few other minor changes
to make the next CL - an automated one - smoother.

Change-Id: Ie787a34732efd5b3d171bf0c1220b6dd91994ce3
Reviewed-on: https://go-review.googlesource.com/c/go/+/272251
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

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

@@ -140,6 +140,41 @@ type EscEdge struct {
 	notes  *EscNote
 }
 
+func init() {
+	EscFmt = escFmt
+}
+
+// escFmt is called from node printing to print information about escape analysis results.
+func escFmt(n *Node, short bool) string {
+	text := ""
+	switch n.Esc {
+	case EscUnknown:
+		break
+
+	case EscHeap:
+		text = "esc(h)"
+
+	case EscNone:
+		text = "esc(no)"
+
+	case EscNever:
+		if !short {
+			text = "esc(N)"
+		}
+
+	default:
+		text = fmt.Sprintf("esc(%d)", n.Esc)
+	}
+
+	if e, ok := n.Opt().(*EscLocation); ok && e.loopDepth != 0 {
+		if text != "" {
+			text += " "
+		}
+		text += fmt.Sprintf("ld(%d)", e.loopDepth)
+	}
+	return text
+}
+
 // escapeFuncs performs escape analysis on a minimal batch of
 // functions.
 func escapeFuncs(fns []*Node, recursive bool) {

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

@@ -415,19 +415,22 @@ func (n *Node) format(s fmt.State, verb rune, mode fmtMode) {
 	}
 }
 
+// EscFmt is set by the escape analysis code to add escape analysis details to the node print.
+var EscFmt func(n *Node, short bool) string
+
 // *Node details
 func (n *Node) jconv(s fmt.State, flag FmtFlag) {
-	c := flag & FmtShort
+	short := flag&FmtShort != 0
 
-	// Useful to see which nodes in a Node Dump/dumplist are actually identical
+	// Useful to see which nodes in an AST printout are actually identical
 	if Debug_dumpptrs != 0 {
 		fmt.Fprintf(s, " p(%p)", n)
 	}
-	if c == 0 && n.Name != nil && n.Name.Vargen != 0 {
+	if !short && n.Name != nil && n.Name.Vargen != 0 {
 		fmt.Fprintf(s, " g(%d)", n.Name.Vargen)
 	}
 
-	if Debug_dumpptrs != 0 && c == 0 && n.Name != nil && n.Name.Defn != nil {
+	if Debug_dumpptrs != 0 && !short && n.Name != nil && n.Name.Defn != nil {
 		// Useful to see where Defn is set and what node it points to
 		fmt.Fprintf(s, " defn(%p)", n.Name.Defn)
 	}
@@ -443,7 +446,7 @@ func (n *Node) jconv(s fmt.State, flag FmtFlag) {
 		fmt.Fprintf(s, " l(%s%d)", pfx, n.Pos.Line())
 	}
 
-	if c == 0 && n.Xoffset != BADWIDTH {
+	if !short && n.Xoffset != BADWIDTH {
 		fmt.Fprintf(s, " x(%d)", n.Xoffset)
 	}
 
@@ -455,30 +458,13 @@ func (n *Node) jconv(s fmt.State, flag FmtFlag) {
 		fmt.Fprintf(s, " colas(%v)", n.Colas())
 	}
 
-	switch n.Esc {
-	case EscUnknown:
-		break
-
-	case EscHeap:
-		fmt.Fprint(s, " esc(h)")
-
-	case EscNone:
-		fmt.Fprint(s, " esc(no)")
-
-	case EscNever:
-		if c == 0 {
-			fmt.Fprint(s, " esc(N)")
+	if EscFmt != nil {
+		if esc := EscFmt(n, short); esc != "" {
+			fmt.Fprintf(s, " %s", esc)
+		}
 	}
 
-	default:
-		fmt.Fprintf(s, " esc(%d)", n.Esc)
-	}
-
-	if e, ok := n.Opt().(*EscLocation); ok && e.loopDepth != 0 {
-		fmt.Fprintf(s, " ld(%d)", e.loopDepth)
-	}
-
-	if c == 0 && n.Typecheck() != 0 {
+	if !short && n.Typecheck() != 0 {
 		fmt.Fprintf(s, " tc(%d)", n.Typecheck())
 	}
 
@@ -518,11 +504,11 @@ func (n *Node) jconv(s fmt.State, flag FmtFlag) {
 		fmt.Fprint(s, " nonnil")
 	}
 
-	if c == 0 && n.HasCall() {
+	if !short && n.HasCall() {
 		fmt.Fprint(s, " hascall")
 	}
 
-	if c == 0 && n.Name != nil && n.Name.Used() {
+	if !short && n.Name != nil && n.Name.Used() {
 		fmt.Fprint(s, " used")
 	}
 }

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

@@ -98,16 +98,16 @@ func (r *intReader) uint64() uint64 {
 }
 
 func iimport(pkg *types.Pkg, in *bio.Reader) (fingerprint goobj.FingerprintType) {
-	ir := &intReader{in, pkg}
+	ird := &intReader{in, pkg}
 
-	version := ir.uint64()
+	version := ird.uint64()
 	if version != iexportVersion {
 		yyerror("import %q: unknown export format version %d", pkg.Path, version)
 		errorexit()
 	}
 
-	sLen := ir.uint64()
-	dLen := ir.uint64()
+	sLen := ird.uint64()
+	dLen := ird.uint64()
 
 	// Map string (and data) section into memory as a single large
 	// string. This reduces heap fragmentation and allows
@@ -138,10 +138,10 @@ func iimport(pkg *types.Pkg, in *bio.Reader) (fingerprint goobj.FingerprintType)
 	}
 
 	// Declaration index.
-	for nPkgs := ir.uint64(); nPkgs > 0; nPkgs-- {
-		pkg := p.pkgAt(ir.uint64())
-		pkgName := p.stringAt(ir.uint64())
-		pkgHeight := int(ir.uint64())
+	for nPkgs := ird.uint64(); nPkgs > 0; nPkgs-- {
+		pkg := p.pkgAt(ird.uint64())
+		pkgName := p.stringAt(ird.uint64())
+		pkgHeight := int(ird.uint64())
 		if pkg.Name == "" {
 			pkg.Name = pkgName
 			pkg.Height = pkgHeight
@@ -158,9 +158,9 @@ func iimport(pkg *types.Pkg, in *bio.Reader) (fingerprint goobj.FingerprintType)
 			}
 		}
 
-		for nSyms := ir.uint64(); nSyms > 0; nSyms-- {
-			s := pkg.Lookup(p.stringAt(ir.uint64()))
-			off := ir.uint64()
+		for nSyms := ird.uint64(); nSyms > 0; nSyms-- {
+			s := pkg.Lookup(p.stringAt(ird.uint64()))
+			off := ird.uint64()
 
 			if _, ok := declImporter[s]; ok {
 				continue
@@ -177,12 +177,12 @@ func iimport(pkg *types.Pkg, in *bio.Reader) (fingerprint goobj.FingerprintType)
 	}
 
 	// Inline body index.
-	for nPkgs := ir.uint64(); nPkgs > 0; nPkgs-- {
-		pkg := p.pkgAt(ir.uint64())
+	for nPkgs := ird.uint64(); nPkgs > 0; nPkgs-- {
+		pkg := p.pkgAt(ird.uint64())
 
-		for nSyms := ir.uint64(); nSyms > 0; nSyms-- {
-			s := pkg.Lookup(p.stringAt(ir.uint64()))
-			off := ir.uint64()
+		for nSyms := ird.uint64(); nSyms > 0; nSyms-- {
+			s := pkg.Lookup(p.stringAt(ird.uint64()))
+			off := ird.uint64()
 
 			if _, ok := inlineImporter[s]; ok {
 				continue

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

@@ -1585,15 +1585,6 @@ func liststmt(l []*Node) *Node {
 	return n
 }
 
-func (l Nodes) asblock() *Node {
-	n := nod(OBLOCK, nil, nil)
-	n.List = l
-	if l.Len() != 0 {
-		n.Pos = l.First().Pos
-	}
-	return n
-}
-
 func ngotype(n *Node) *types.Sym {
 	if n.Type != nil {
 		return typenamesym(n.Type)

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

@@ -3867,7 +3867,7 @@ func checkreturn(fn *Node) {
 }
 
 func deadcode(fn *Node) {
-	deadcodeslice(fn.Nbody)
+	deadcodeslice(&fn.Nbody)
 	deadcodefn(fn)
 }
 
@@ -3897,7 +3897,7 @@ func deadcodefn(fn *Node) {
 	fn.Nbody.Set([]*Node{nod(OEMPTY, nil, nil)})
 }
 
-func deadcodeslice(nn Nodes) {
+func deadcodeslice(nn *Nodes) {
 	var lastLabel = -1
 	for i, n := range nn.Slice() {
 		if n != nil && n.Op == OLABEL {
@@ -3939,12 +3939,12 @@ func deadcodeslice(nn Nodes) {
 			}
 		}
 
-		deadcodeslice(n.Ninit)
-		deadcodeslice(n.Nbody)
-		deadcodeslice(n.List)
-		deadcodeslice(n.Rlist)
+		deadcodeslice(&n.Ninit)
+		deadcodeslice(&n.Nbody)
+		deadcodeslice(&n.List)
+		deadcodeslice(&n.Rlist)
 		if cut {
-			*nn.slice = nn.Slice()[:i+1]
+			nn.Set(nn.Slice()[:i+1])
 			break
 		}
 	}