cmd/compile: simplify lexinit and lexfini

Split the syms array into separate basicTypes and builtinFuncs arrays.

Also, in lexfini, instead of duplicating the code from lexinit to
declare the builtin identifiers in the user package, just import them
from builtinpkg like how importdot works.

Change-Id: Ic3b3b454627a46f7bd5f290d0e31443e659d431f
Reviewed-on: https://go-review.googlesource.com/19936
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

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

@@ -2067,77 +2067,75 @@ func (l *lexer) hexchar(n int) uint32 {
 	return x
 }
 
-var syms = []struct {
+var basicTypes = [...]struct {
 	name  string
 	etype EType
-	op    Op
 }{
-	// basic types
-	{"int8", TINT8, OXXX},
-	{"int16", TINT16, OXXX},
-	{"int32", TINT32, OXXX},
-	{"int64", TINT64, OXXX},
-	{"uint8", TUINT8, OXXX},
-	{"uint16", TUINT16, OXXX},
-	{"uint32", TUINT32, OXXX},
-	{"uint64", TUINT64, OXXX},
-	{"float32", TFLOAT32, OXXX},
-	{"float64", TFLOAT64, OXXX},
-	{"complex64", TCOMPLEX64, OXXX},
-	{"complex128", TCOMPLEX128, OXXX},
-	{"bool", TBOOL, OXXX},
-	{"string", TSTRING, OXXX},
-	{"any", TANY, OXXX},
-
-	// builtin funcs
-	{"append", Txxx, OAPPEND},
-	{"cap", Txxx, OCAP},
-	{"close", Txxx, OCLOSE},
-	{"complex", Txxx, OCOMPLEX},
-	{"copy", Txxx, OCOPY},
-	{"delete", Txxx, ODELETE},
-	{"imag", Txxx, OIMAG},
-	{"len", Txxx, OLEN},
-	{"make", Txxx, OMAKE},
-	{"new", Txxx, ONEW},
-	{"panic", Txxx, OPANIC},
-	{"print", Txxx, OPRINT},
-	{"println", Txxx, OPRINTN},
-	{"real", Txxx, OREAL},
-	{"recover", Txxx, ORECOVER},
+	{"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},
+	{"any", TANY},
+}
+
+var builtinFuncs = [...]struct {
+	name string
+	op   Op
+}{
+	{"append", OAPPEND},
+	{"cap", OCAP},
+	{"close", OCLOSE},
+	{"complex", OCOMPLEX},
+	{"copy", OCOPY},
+	{"delete", ODELETE},
+	{"imag", OIMAG},
+	{"len", OLEN},
+	{"make", OMAKE},
+	{"new", ONEW},
+	{"panic", OPANIC},
+	{"print", OPRINT},
+	{"println", OPRINTN},
+	{"real", OREAL},
+	{"recover", ORECOVER},
 }
 
 // lexinit initializes known symbols and the basic types.
 func lexinit() {
-	for _, s := range syms {
-		if etype := s.etype; etype != Txxx {
-			if int(etype) >= len(Types) {
-				Fatalf("lexinit: %s bad etype", s.name)
+	for _, s := range basicTypes {
+		etype := s.etype
+		if int(etype) >= len(Types) {
+			Fatalf("lexinit: %s bad etype", s.name)
+		}
+		s2 := Pkglookup(s.name, builtinpkg)
+		t := Types[etype]
+		if t == nil {
+			t = typ(etype)
+			t.Sym = s2
+			if etype != TANY && etype != TSTRING {
+				dowidth(t)
 			}
-			s2 := Pkglookup(s.name, builtinpkg)
-			t := Types[etype]
-			if t == nil {
-				t = typ(etype)
-				t.Sym = s2
-
-				if etype != TANY && etype != TSTRING {
-					dowidth(t)
-				}
-				Types[etype] = t
-			}
-
-			s2.Def = typenod(t)
-			s2.Def.Name = new(Name)
-			continue
+			Types[etype] = t
 		}
+		s2.Def = typenod(t)
+		s2.Def.Name = new(Name)
+	}
 
+	for _, s := range builtinFuncs {
 		// TODO(marvin): Fix Node.EType type union.
-		if etype := s.op; etype != OXXX {
-			s2 := Pkglookup(s.name, builtinpkg)
-			s2.Def = Nod(ONAME, nil, nil)
-			s2.Def.Sym = s2
-			s2.Def.Etype = EType(etype)
-		}
+		s2 := Pkglookup(s.name, builtinpkg)
+		s2.Def = Nod(ONAME, nil, nil)
+		s2.Def.Sym = s2
+		s2.Def.Etype = EType(s.op)
 	}
 
 	// logically, the type of a string literal.
@@ -2183,6 +2181,11 @@ func lexinit() {
 	s.Def = nodlit(v)
 	s.Def.Sym = s
 	s.Def.Name = new(Name)
+
+	s = Pkglookup("iota", builtinpkg)
+	s.Def = Nod(OIOTA, nil, nil)
+	s.Def.Sym = s
+	s.Def.Name = new(Name)
 }
 
 func lexinit1() {
@@ -2230,86 +2233,28 @@ func lexinit1() {
 	runetype.Sym = s
 	s.Def = typenod(runetype)
 	s.Def.Name = new(Name)
-}
-
-func lexfini() {
-	for i := range syms {
-		s := Lookup(syms[i].name)
-
-		etype := syms[i].etype
-		if etype != Txxx && (etype != TANY || Debug['A'] != 0) && s.Def == nil {
-			s.Def = typenod(Types[etype])
-			s.Def.Name = new(Name)
-			s.Origpkg = builtinpkg
-		}
-
-		// TODO(marvin): Fix Node.EType type union.
-		etype = EType(syms[i].op)
-		if etype != EType(OXXX) && s.Def == nil {
-			s.Def = Nod(ONAME, nil, nil)
-			s.Def.Sym = s
-			s.Def.Etype = etype
-			s.Origpkg = builtinpkg
-		}
-	}
 
 	// backend-specific builtin types (e.g. int).
 	for i := range Thearch.Typedefs {
-		s := Lookup(Thearch.Typedefs[i].Name)
-		if s.Def == nil {
-			s.Def = typenod(Types[Thearch.Typedefs[i].Etype])
-			s.Def.Name = new(Name)
-			s.Origpkg = builtinpkg
-		}
-	}
-
-	// there's only so much table-driven we can handle.
-	// these are special cases.
-	if s := Lookup("byte"); s.Def == nil {
-		s.Def = typenod(bytetype)
+		s := Pkglookup(Thearch.Typedefs[i].Name, builtinpkg)
+		s.Def = typenod(Types[Thearch.Typedefs[i].Etype])
 		s.Def.Name = new(Name)
 		s.Origpkg = builtinpkg
 	}
+}
 
-	if s := Lookup("error"); s.Def == nil {
-		s.Def = typenod(errortype)
-		s.Def.Name = new(Name)
-		s.Origpkg = builtinpkg
-	}
-
-	if s := Lookup("rune"); s.Def == nil {
-		s.Def = typenod(runetype)
-		s.Def.Name = new(Name)
-		s.Origpkg = builtinpkg
-	}
-
-	if s := Lookup("nil"); s.Def == nil {
-		var v Val
-		v.U = new(NilVal)
-		s.Def = nodlit(v)
-		s.Def.Sym = s
-		s.Def.Name = new(Name)
-		s.Origpkg = builtinpkg
-	}
-
-	if s := Lookup("iota"); s.Def == nil {
-		s.Def = Nod(OIOTA, nil, nil)
-		s.Def.Sym = s
-		s.Origpkg = builtinpkg
-	}
-
-	if s := Lookup("true"); s.Def == nil {
-		s.Def = Nodbool(true)
-		s.Def.Sym = s
-		s.Def.Name = new(Name)
-		s.Origpkg = builtinpkg
-	}
+func lexfini() {
+	for _, s := range builtinpkg.Syms {
+		if s.Def == nil {
+			continue
+		}
+		s1 := Lookup(s.Name)
+		if s1.Def != nil {
+			continue
+		}
 
-	if s := Lookup("false"); s.Def == nil {
-		s.Def = Nodbool(false)
-		s.Def.Sym = s
-		s.Def.Name = new(Name)
-		s.Origpkg = builtinpkg
+		s1.Def = s.Def
+		s1.Block = s.Block
 	}
 
 	nodfp = Nod(ONAME, nil, nil)