cmd/compile/internal/gc: add line numbers for complit elts if needed (addresses TODO)

For #13243.

Change-Id: I802cef3dad5d1236e70d0cd52047008a6a7a311a
Reviewed-on: https://go-review.googlesource.com/17045
Reviewed-by: Chris Manghane <cmang@golang.org>

diff --git a/src/cmd/compile/internal/gc/parser.go b/src/cmd/compile/internal/gc/parser.go
index 94814cb5398abc274a17d2683e56909471f88e8c..51d04f59fe5bd0617c965a854fadd4fa3bc80ac4 100644 (file)
--- a/src/cmd/compile/internal/gc/parser.go
+++ b/src/cmd/compile/internal/gc/parser.go
@@ -659,15 +659,10 @@ func (p *parser) simple_stmt(labelOk, rangeOk bool) *Node {
 
                default:
                        // expr
-                       // These nodes do not carry line numbers.
                        // Since a bare name used as an expression is an error,
-                       // introduce a wrapper node to give the correct line.
-                       switch lhs.Op {
-                       case ONAME, ONONAME, OTYPE, OPACK, OLITERAL:
-                               lhs = Nod(OPAREN, lhs, nil)
-                               lhs.Implicit = true
-                       }
-                       return lhs
+                       // introduce a wrapper node where necessary to give the
+                       // correct line.
+                       return wrapname(lhs)
                }
        }
 
@@ -1626,9 +1621,29 @@ func (p *parser) keyval() *Node {
                defer p.trace("keyval")()
        }
 
+       // A composite literal commonly spans several lines,
+       // so the line number on errors may be misleading.
+       // Wrap values (but not keys!) that don't carry line
+       // numbers.
+
        x := p.bare_complitexpr()
+
        if p.got(':') {
-               x = Nod(OKEY, x, p.bare_complitexpr())
+               // key ':' value
+               return Nod(OKEY, x, wrapname(p.bare_complitexpr()))
+       }
+
+       // value
+       return wrapname(x)
+}
+
+func wrapname(x *Node) *Node {
+       // These nodes do not carry line numbers.
+       // Introduce a wrapper node to give the correct line.
+       switch x.Op {
+       case ONAME, ONONAME, OTYPE, OPACK, OLITERAL:
+               x = Nod(OPAREN, x, nil)
+               x.Implicit = true
        }
        return x
 }
@@ -1644,21 +1659,7 @@ func (p *parser) bare_complitexpr() *Node {
                return p.complitexpr()
        }
 
-       x := p.expr()
-
-       // These nodes do not carry line numbers.
-       // Since a composite literal commonly spans several lines,
-       // the line number on errors may be misleading.
-       // Introduce a wrapper node to give the correct line.
-
-       // TODO(gri) This is causing trouble when used for keys. Need to fix complit parsing.
-       // switch x.Op {
-       // case ONAME, ONONAME, OTYPE, OPACK, OLITERAL:
-       //      x = Nod(OPAREN, x, nil)
-       //      x.Implicit = true
-       // }
-       // (issue 13243)
-       return x
+       return p.expr()
 }
 
 // go.y:complitexpr