[dev.typealias] cmd/compile: various minor cleanups

Also: Don't allow type pragmas with type alias declarations.

For #18130.

Change-Id: Ie54ea5fefcd677ad87ced03466bbfd783771e974
Reviewed-on: https://go-review.googlesource.com/35102
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go
index 75f58a731c079f1bae8f7c19bfc4dd5467caa653..b0b31dd30dbdbc8ea9d38dc65b353a9e2f7ca2b7 100644 (file)
--- a/src/cmd/compile/internal/gc/main.go
+++ b/src/cmd/compile/internal/gc/main.go
@@ -344,8 +344,9 @@ func Main() {
        // Don't use range--typecheck can add closures to xtop.
        timings.Start("fe", "typecheck", "top1")
        for i := 0; i < len(xtop); i++ {
-               if xtop[i].Op != ODCL && xtop[i].Op != OAS && xtop[i].Op != OAS2 {
-                       xtop[i] = typecheck(xtop[i], Etop)
+               n := xtop[i]
+               if op := n.Op; op != ODCL && op != OAS && op != OAS2 {
+                       xtop[i] = typecheck(n, Etop)
                }
        }
 
@@ -355,8 +356,9 @@ func Main() {
        // Don't use range--typecheck can add closures to xtop.
        timings.Start("fe", "typecheck", "top2")
        for i := 0; i < len(xtop); i++ {
-               if xtop[i].Op == ODCL || xtop[i].Op == OAS || xtop[i].Op == OAS2 {
-                       xtop[i] = typecheck(xtop[i], Etop)
+               n := xtop[i]
+               if op := n.Op; op == ODCL || op == OAS || op == OAS2 {
+                       xtop[i] = typecheck(n, Etop)
                }
        }
        resumecheckwidth()
@@ -366,8 +368,9 @@ func Main() {
        timings.Start("fe", "typecheck", "func")
        var fcount int64
        for i := 0; i < len(xtop); i++ {
-               if xtop[i].Op == ODCLFUNC || xtop[i].Op == OCLOSURE {
-                       Curfn = xtop[i]
+               n := xtop[i]
+               if op := n.Op; op == ODCLFUNC || op == OCLOSURE {
+                       Curfn = n
                        decldepth = 1
                        saveerrors()
                        typecheckslice(Curfn.Nbody.Slice(), Etop)
@@ -459,8 +462,9 @@ func Main() {
        timings.Start("be", "compilefuncs")
        fcount = 0
        for i := 0; i < len(xtop); i++ {
-               if xtop[i].Op == ODCLFUNC {
-                       funccompile(xtop[i])
+               n := xtop[i]
+               if n.Op == ODCLFUNC {
+                       funccompile(n)
                        fcount++
                }
        }

diff --git a/src/cmd/compile/internal/gc/noder.go b/src/cmd/compile/internal/gc/noder.go
index 3f6fe20b6b8bb9e11b626988c86a0d88a17716f3..8d830ad62d2b4558cc84c8e2545dde79bea574ed 100644 (file)
--- a/src/cmd/compile/internal/gc/noder.go
+++ b/src/cmd/compile/internal/gc/noder.go
@@ -153,11 +153,7 @@ func (p *noder) importDecl(imp *syntax.ImportDecl) {
 
 func (p *noder) varDecl(decl *syntax.VarDecl) []*Node {
        names := p.declNames(decl.NameList)
-
-       var typ *Node
-       if decl.Type != nil {
-               typ = p.typeExpr(decl.Type)
-       }
+       typ := p.typeExprOrNil(decl.Type)
 
        var exprs []*Node
        if decl.Values != nil {
@@ -170,11 +166,7 @@ func (p *noder) varDecl(decl *syntax.VarDecl) []*Node {
 
 func (p *noder) constDecl(decl *syntax.ConstDecl) []*Node {
        names := p.declNames(decl.NameList)
-
-       var typ *Node
-       if decl.Type != nil {
-               typ = p.typeExpr(decl.Type)
-       }
+       typ := p.typeExprOrNil(decl.Type)
 
        var exprs []*Node
        if decl.Values != nil {
@@ -190,12 +182,14 @@ func (p *noder) typeDecl(decl *syntax.TypeDecl) *Node {
        }
 
        name := typedcl0(p.name(decl.Name))
-       name.Name.Param.Pragma = Pragma(decl.Pragma)
-
-       var typ *Node
-       if decl.Type != nil {
-               typ = p.typeExpr(decl.Type)
+       pragma := Pragma(decl.Pragma)
+       if pragma != 0 && decl.Alias {
+               yyerror("cannot specify directive with type alias")
+               pragma = 0
        }
+       name.Name.Param.Pragma = pragma
+
+       typ := p.typeExprOrNil(decl.Type)
 
        return typedcl1(name, typ, true)
 }
@@ -470,6 +464,13 @@ func (p *noder) typeExpr(typ syntax.Expr) *Node {
        return p.expr(typ)
 }
 
+func (p *noder) typeExprOrNil(typ syntax.Expr) *Node {
+       if typ != nil {
+               return p.expr(typ)
+       }
+       return nil
+}
+
 func (p *noder) chanDir(dir syntax.ChanDir) ChanDir {
        switch dir {
        case 0: