From d40f032d1878f9ff271898e7db70a5ee9f269469 Mon Sep 17 00:00:00 2001
From: Ken Thompson <ken@golang.org>
Date: Tue, 9 Sep 2008 15:47:31 -0700
Subject: [PATCH] fixed bug in certain evaluation of complex literals

R=r
OCL=15036
CL=15036
---
 src/cmd/6g/gen.c  |  9 ++++++++
 src/cmd/gc/go.y   | 19 ++++++-----------
 src/cmd/gc/walk.c | 54 +++++++++++++++++++++++++++++++++++++----------
 3 files changed, 58 insertions(+), 24 deletions(-)

diff --git a/src/cmd/6g/gen.c b/src/cmd/6g/gen.c
index d2caaca39c1..dbdafd61279 100644
--- a/src/cmd/6g/gen.c
+++ b/src/cmd/6g/gen.c
@@ -244,6 +244,9 @@ loop:
 		continpc = pc;
 		gen(n->nincr, L);				// contin:	incr
 		patch(p1, pc);				// test:
+		if(n->ntest != N)
+			if(n->ntest->ninit != N)
+				gen(n->ntest->ninit, L);
 		bgen(n->ntest, 0, breakpc);		//		if(!test) goto break
 		if(labloop != L) {
 			labloop->op = OFOR;
@@ -261,6 +264,9 @@ loop:
 		p1 = gbranch(AJMP, T);			//		goto test
 		p2 = gbranch(AJMP, T);			// p2:		goto else
 		patch(p1, pc);				// test:
+		if(n->ntest != N)
+			if(n->ntest->ninit != N)
+				gen(n->ntest->ninit, L);
 		bgen(n->ntest, 0, p2);			// 		if(!test) goto p2
 		gen(n->nbody, L);			//		then
 		p3 = gbranch(AJMP, T);			//		goto done
@@ -522,6 +528,9 @@ swgen(Node *n)
 
 	patch(p1, pc);
 
+	if(n->ntest != N)
+		if(n->ntest->ninit != N)
+			gen(n->ntest->ninit, L);
 	tempname(&tmp, n->ntest->type);
 	cgen(n->ntest, &tmp);
 
diff --git a/src/cmd/gc/go.y b/src/cmd/gc/go.y
index be5d0867fc1..ac806cc6fff 100644
--- a/src/cmd/gc/go.y
+++ b/src/cmd/gc/go.y
@@ -250,7 +250,7 @@ Bvardcl:
 	}
 |	new_name '=' expr
 	{
-		walktype($3, Erv);	// this is a little harry
+		gettype($3);
 		defaultlit($3);
 		dodclvar($1, $3->type);
 		$$ = nod(OAS, $1, $3);
@@ -260,7 +260,7 @@ constdcl:
 	new_name type '=' expr
 	{
 		Node *c = treecopy($4);
-		walktype(c, Erv);
+		gettype(c);
 		convlit(c, $2);
 		dodclconst($1, c);
 
@@ -270,7 +270,7 @@ constdcl:
 |	new_name '=' expr
 	{
 		Node *c = treecopy($3);
-		walktype(c, Erv);
+		gettype(c);
 		dodclconst($1, c);
 
 		lastconst = $3;
@@ -282,7 +282,7 @@ constdcl1:
 |	new_name type
 	{
 		Node *c = treecopy(lastconst);
-		walktype(c, Erv);
+		gettype(c);
 		convlit(c, $2);
 		dodclconst($1, c);
 
@@ -291,7 +291,7 @@ constdcl1:
 |	new_name
 	{
 		Node *c = treecopy(lastconst);
-		walktype(c, Erv);
+		gettype(c);
 		dodclconst($1, c);
 
 		iota += 1;
@@ -346,6 +346,7 @@ noninc_stmt:
 |	expr_list LCOLAS expr_list
 	{
 		$$ = nod(OAS, colas($1, $3), $3);
+		addtotop($$);
 	}
 |	LPRINT '(' oexpr_list ')'
 	{
@@ -379,23 +380,17 @@ complex_stmt:
 		popdcl();
 		$$ = $2;
 		$$->op = OSWITCH;
-		//if($$->ninit != N && $$->ntest == N)
-		//	yyerror("switch expression should not be missing");
 	}
 |	LIF if_stmt
 	{
 		popdcl();
 		$$ = $2;
-		//if($$->ninit != N && $$->ntest == N)
-		//	yyerror("if conditional should not be missing");
 	}
 |	LIF if_stmt LELSE else_stmt1
 	{
 		popdcl();
 		$$ = $2;
 		$$->nelse = $4;
-		//if($$->ninit != N && $$->ntest == N)
-		//	yyerror("if conditional should not be missing");
 	}
 |	LSELECT select_stmt
 	{
@@ -453,8 +448,6 @@ semi_stmt:
 		popdcl();
 		$$ = $2;
 		$$->nelse = $4;
-		//if($$->ninit != N && $$->ntest == N)
-		//	yyerror("if conditional should not be missing");
 	}
 
 compound_stmt:
diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index 37c3ccd7426..8c26ac932f5 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -13,18 +13,48 @@ static	Node*	addtop;
 void
 walk(Node *fn)
 {
-	if(debug['W'])
-		dump("fn-before", fn->nbody);
+	char s[50];
+
 	curfn = fn;
+	if(debug['W']) {
+		snprint(s, sizeof(s), "\nbefore %S", curfn->nname->sym);
+		dump(s, fn->nbody);
+	}
 	walkstate(fn->nbody);
+	if(debug['W']) {
+		snprint(s, sizeof(s), "after %S", curfn->nname->sym);
+		dump(s, fn->nbody);
+	}
+}
+
+void
+addtotop(Node *n)
+{
+	Node *l;
+
+	while(addtop != N) {
+		l = addtop;
+		addtop = N;
+		walktype(l, Etop);
+		n->ninit = list(n->ninit, l);
+	}
+}
+
+void
+gettype(Node *n)
+{
 	if(debug['W'])
-		dump("fn", fn->nbody);
+		dump("\nbefore gettype", n);
+	walktype(n, Erv);
+	addtotop(n);
+	if(debug['W'])
+		dump("after gettype", n);
 }
 
 void
 walkstate(Node *n)
 {
-	Node *l, *more;
+	Node *more;
 
 loop:
 	if(n == N)
@@ -69,12 +99,7 @@ loop:
 		break;
 	}
 
-	while(addtop != N) {
-		l = addtop;
-		addtop = N;
-		walktype(l, Etop);
-		n->ninit = list(n->ninit, l);
-	}
+	addtotop(n);
 
 	if(more != N) {
 		n = more;
@@ -227,8 +252,8 @@ loop:
 			goto nottop;
 		walkstate(n->ninit);
 		walkbool(n->ntest);
-		walkstate(n->nelse);
 		walkstate(n->nbody);
+		walkstate(n->nelse);
 		goto ret;
 
 	case OPROC:
@@ -307,6 +332,9 @@ loop:
 		if(top != Etop)
 			goto nottop;
 
+		addtop = list(addtop, n->ninit);
+		n->ninit = N;
+
 		l = n->left;
 		r = n->right;
 		walktype(l, Elv);
@@ -948,6 +976,7 @@ void
 walkbool(Node *n)
 {
 	walktype(n, Erv);
+	addtotop(n);
 	if(n != N && n->type != T)
 		if(!eqtype(n->type, types[TBOOL], 0))
 			yyerror("IF and FOR require a boolean type");
@@ -1545,6 +1574,8 @@ loop:
 	w = whatis(l);
 	switch(w) {
 	default:
+		if(l->type == T)
+			goto out;
 		if(!isptr[l->type->etype]) {
 			badtype(n->op, l->type, T);
 			l = listnext(&save);
@@ -1588,6 +1619,7 @@ loop:
 	else
 		r = list(r, nod(OCALL, on, l));
 
+out:
 	l = listnext(&save);
 	goto loop;
 }