Commit 112267d5 authored by Russ Cox's avatar Russ Cox

gc: diagnose (x) := 0

Fixes #1756.

R=ken2
CC=golang-dev
https://golang.org/cl/4810057
parent db3088a3
......@@ -457,17 +457,19 @@ colasname(Node *n)
void
colasdefn(NodeList *left, Node *defn)
{
int nnew;
int nnew, nerr;
NodeList *l;
Node *n;
nnew = 0;
nerr = 0;
for(l=left; l; l=l->next) {
n = l->n;
if(isblank(n))
continue;
if(!colasname(n)) {
yyerror("non-name %#N on left side of :=", n);
nerr++;
continue;
}
if(n->sym->block == block)
......@@ -480,7 +482,7 @@ colasdefn(NodeList *left, Node *defn)
defn->ninit = list(defn->ninit, nod(ODCL, n, N));
l->n = n;
}
if(nnew == 0)
if(nnew == 0 && nerr == 0)
yyerror("no new variables on left side of :=");
}
......
......@@ -393,6 +393,7 @@ enum
ONOT, OCOM, OPLUS, OMINUS,
OOROR,
OPANIC, OPRINT, OPRINTN,
OPAREN,
OSEND,
OSLICE, OSLICEARR, OSLICESTR,
ORECOVER,
......
......@@ -916,6 +916,18 @@ pexpr:
| '(' expr_or_type ')'
{
$$ = $2;
// Need to know on lhs of := whether there are ( ).
// Don't bother with the OPAREN in other cases:
// it's just a waste of memory and time.
switch($$->op) {
case ONAME:
case ONONAME:
case OPACK:
case OTYPE:
case OLITERAL:
$$ = nod(OPAREN, $$, N);
}
}
expr_or_type:
......
......@@ -78,6 +78,7 @@ exprfmt(Fmt *f, Node *n, int prec)
case OTPAREN:
case OINDEX:
case OINDEXMAP:
case OPAREN:
nprec = 7;
break;
......@@ -134,6 +135,10 @@ exprfmt(Fmt *f, Node *n, int prec)
fmtprint(f, "(node %O)", n->op);
break;
case OPAREN:
fmtprint(f, "(%#N)", n->left);
break;
case OREGISTER:
fmtprint(f, "%R", n->val.u.reg);
break;
......
......@@ -124,9 +124,16 @@ typecheck(Node **np, int top)
n = *np;
if(n == N)
return N;
lno = setlineno(n);
// Skip over parens.
while(n->op == OPAREN)
n = n->left;
// Resolve definition of name and value of iota lazily.
n = resolve(n);
*np = n;
// Skip typecheck if already done.
......
// errchk $G $D/$F.go
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
func main() {
(x) := 0 // ERROR "non-name [(]x[)]"
}
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