gc: print detail for typechecking loop error
R=ken2
CC=golang-dev
https://golang.org/cl/5654060
diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index 91f5458..b791c9e 100644
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -111,16 +111,15 @@
* replaces *np with a new pointer in some cases.
* returns the final value of *np as a convenience.
*/
+static void typecheck1(Node **, int);
Node*
typecheck(Node **np, int top)
{
- int et, aop, op, ptr;
- Node *n, *l, *r;
- NodeList *args;
- int lno, ok, ntop;
- Type *t, *tp, *ft, *missing, *have, *badtype;
- Val v;
- char *why;
+ Node *n;
+ int lno;
+ Fmt fmt;
+ NodeList *l;
+ static NodeList *tcstack, *tcfree;
// cannot type check until all the source has been parsed
if(!typecheckok)
@@ -157,11 +156,52 @@
}
if(n->typecheck == 2) {
- yyerror("typechecking loop involving %N", n);
+ if(nsavederrors+nerrors == 0) {
+ fmtstrinit(&fmt);
+ for(l=tcstack; l; l=l->next)
+ fmtprint(&fmt, "\n\t%L %N", l->n->lineno, l->n);
+ yyerror("typechecking loop involving %N%s", n, fmtstrflush(&fmt));
+ }
lineno = lno;
return n;
}
n->typecheck = 2;
+
+ if(tcfree != nil) {
+ l = tcfree;
+ tcfree = l->next;
+ } else
+ l = mal(sizeof *l);
+ l->next = tcstack;
+ l->n = n;
+ tcstack = l;
+
+ typecheck1(&n, top);
+ *np = n;
+ n->typecheck = 1;
+
+ if(tcstack != l)
+ fatal("typecheck stack out of sync");
+ tcstack = l->next;
+ l->next = tcfree;
+ tcfree = l;
+
+ lineno = lno;
+ return n;
+}
+
+static void
+typecheck1(Node **np, int top)
+{
+ int et, aop, op, ptr;
+ Node *n, *l, *r;
+ NodeList *args;
+ int ok, ntop;
+ Type *t, *tp, *ft, *missing, *have, *badtype;
+ Val v;
+ char *why;
+
+ n = *np;
if(n->sym) {
if(n->op == ONAME && n->etype != 0 && !(top & Ecall)) {
@@ -1484,10 +1524,7 @@
n->type = T;
out:
- lineno = lno;
- n->typecheck = 1;
*np = n;
- return n;
}
static void
