go/parser: first constant in a constant declaration must have a value

R=r, rsc1
CC=golang-dev
https://golang.org/cl/4291042

diff --git a/src/pkg/go/parser/parser.go b/src/pkg/go/parser/parser.go
index 5d4814870c4134b06da9ba7ad6057da86a15df1f..fdf10df6bda9ff800cc9bf634666146318da408b 100644 (file)
--- a/src/pkg/go/parser/parser.go
+++ b/src/pkg/go/parser/parser.go
@@ -1864,10 +1864,10 @@ func (p *parser) parseStmt() (s ast.Stmt) {
 // ----------------------------------------------------------------------------
 // Declarations
 
-type parseSpecFunction func(p *parser, doc *ast.CommentGroup) ast.Spec
+type parseSpecFunction func(p *parser, doc *ast.CommentGroup, iota int) ast.Spec
 
 
-func parseImportSpec(p *parser, doc *ast.CommentGroup) ast.Spec {
+func parseImportSpec(p *parser, doc *ast.CommentGroup, _ int) ast.Spec {
        if p.trace {
                defer un(trace(p, "ImportSpec"))
        }
@@ -1894,7 +1894,7 @@ func parseImportSpec(p *parser, doc *ast.CommentGroup) ast.Spec {
 }
 
 
-func parseConstSpec(p *parser, doc *ast.CommentGroup) ast.Spec {
+func parseConstSpec(p *parser, doc *ast.CommentGroup, iota int) ast.Spec {
        if p.trace {
                defer un(trace(p, "ConstSpec"))
        }
@@ -1902,7 +1902,7 @@ func parseConstSpec(p *parser, doc *ast.CommentGroup) ast.Spec {
        idents := p.parseIdentList()
        typ := p.tryType()
        var values []ast.Expr
-       if typ != nil || p.tok == token.ASSIGN {
+       if typ != nil || p.tok == token.ASSIGN || iota == 0 {
                p.expect(token.ASSIGN)
                values = p.parseExprList()
        }
@@ -1919,7 +1919,7 @@ func parseConstSpec(p *parser, doc *ast.CommentGroup) ast.Spec {
 }
 
 
-func parseTypeSpec(p *parser, doc *ast.CommentGroup) ast.Spec {
+func parseTypeSpec(p *parser, doc *ast.CommentGroup, _ int) ast.Spec {
        if p.trace {
                defer un(trace(p, "TypeSpec"))
        }
@@ -1939,7 +1939,7 @@ func parseTypeSpec(p *parser, doc *ast.CommentGroup) ast.Spec {
 }
 
 
-func parseVarSpec(p *parser, doc *ast.CommentGroup) ast.Spec {
+func parseVarSpec(p *parser, doc *ast.CommentGroup, _ int) ast.Spec {
        if p.trace {
                defer un(trace(p, "VarSpec"))
        }
@@ -1976,13 +1976,13 @@ func (p *parser) parseGenDecl(keyword token.Token, f parseSpecFunction) *ast.Gen
        if p.tok == token.LPAREN {
                lparen = p.pos
                p.next()
-               for p.tok != token.RPAREN && p.tok != token.EOF {
-                       list = append(list, f(p, p.leadComment))
+               for iota := 0; p.tok != token.RPAREN && p.tok != token.EOF; iota++ {
+                       list = append(list, f(p, p.leadComment, iota))
                }
                rparen = p.expect(token.RPAREN)
                p.expectSemi()
        } else {
-               list = append(list, f(p, nil))
+               list = append(list, f(p, nil, 0))
        }
 
        return &ast.GenDecl{doc, pos, keyword, lparen, list, rparen}

diff --git a/src/pkg/go/parser/parser_test.go b/src/pkg/go/parser/parser_test.go
index 8e07d9f87c9c43977d00ddd5a2273ed3f2fc880b..2f1ee6bfc094594355ad638d5261916b4833ceb3 100644 (file)
--- a/src/pkg/go/parser/parser_test.go
+++ b/src/pkg/go/parser/parser_test.go
@@ -21,6 +21,7 @@ var illegalInputs = []interface{}{
        `package p; func f() { if /* should have condition */ {} };`,
        `package p; func f() { if ; /* should have condition */ {} };`,
        `package p; func f() { if f(); /* should have condition */ {} };`,
+       `package p; const c; /* should have constant value */`,
 }