cmd/gc: suppress array index error caused by a previously reported error
Fixes #7153
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/82180043
diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index f6e77ac..5a025a1 100644
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -2525,8 +2525,9 @@
typecheck(&l->left, Erv);
evconst(l->left);
i = nonnegconst(l->left);
- if(i < 0) {
+ if(i < 0 && !l->left->diag) {
yyerror("array index must be non-negative integer constant");
+ l->left->diag = 1;
i = -(1<<30); // stay negative for a while
}
if(i >= 0)
