gc: Nicer errors before miscompiling.

This fixes issue 2444.

A big cleanup of all 31/32bit size boundaries i'll leave for another cl though.  (see also issue 1700).

R=rsc
CC=golang-dev
https://golang.org/cl/5484058

src/cmd/5g/cgen.c

@@ -1193,7 +1193,7 @@ stkof(Node *n)
  * NB: character copy assumed little endian architecture
  */
 void
-sgen(Node *n, Node *res, int32 w)
+sgen(Node *n, Node *res, int64 w)
 {
 	Node dst, src, tmp, nend;
 	int32 c, odst, osrc;
@@ -1201,14 +1201,17 @@ sgen(Node *n, Node *res, int32 w)
 	Prog *p, *ploop;
 
 	if(debug['g']) {
-		print("\nsgen w=%d\n", w);
+		print("\nsgen w=%lld\n", w);
 		dump("r", n);
 		dump("res", res);
 	}
-	if(w < 0)
+
-		fatal("sgen copy %d", w);
 	if(n->ullman >= UINF && res->ullman >= UINF)
 		fatal("sgen UINF");
+
+	if(w < 0 || (int32)w != w)
+		fatal("sgen copy %lld", w);
+
 	if(n->type == T)
 		fatal("sgen: missing type");
 
@@ -1240,7 +1243,7 @@ sgen(Node *n, Node *res, int32 w)
 		break;
 	}
 	if(w%align)
-		fatal("sgen: unaligned size %d (align=%d) for %T", w, align, n->type);
+		fatal("sgen: unaligned size %lld (align=%d) for %T", w, align, n->type);
 	c = w / align;
 
 	// offset on the stack

src/cmd/5g/gg.h

@@ -94,7 +94,7 @@ void	igen(Node*, Node*, Node*);
 void agenr(Node *n, Node *a, Node *res);
 vlong	fieldoffset(Type*, Node*);
 void	bgen(Node*, int, Prog*);
-void	sgen(Node*, Node*, int32);
+void	sgen(Node*, Node*, int64);
 void	gmove(Node*, Node*);
 Prog*	gins(int, Node*, Node*);
 int	samaddr(Node*, Node*);

src/cmd/6g/cgen.c

@@ -1023,13 +1023,13 @@ stkof(Node *n)
  *	memmove(&ns, &n, w);
  */
 void
-sgen(Node *n, Node *ns, int32 w)
+sgen(Node *n, Node *ns, int64 w)
 {
 	Node nodl, nodr, oldl, oldr, cx, oldcx, tmp;
 	int32 c, q, odst, osrc;
 
 	if(debug['g']) {
-		print("\nsgen w=%d\n", w);
+		print("\nsgen w=%lld\n", w);
 		dump("r", n);
 		dump("res", ns);
 	}
@@ -1038,7 +1038,7 @@ sgen(Node *n, Node *ns, int32 w)
 		fatal("sgen UINF");
 
 	if(w < 0)
-		fatal("sgen copy %d", w);
+		fatal("sgen copy %lld", w);
 
 	if(w == 16)
 		if(componentgen(n, ns))

src/cmd/6g/gg.h

@@ -87,7 +87,7 @@ void	agen(Node*, Node*);
 void	igen(Node*, Node*, Node*);
 vlong	fieldoffset(Type*, Node*);
 void	bgen(Node*, int, Prog*);
-void	sgen(Node*, Node*, int32);
+void	sgen(Node*, Node*, int64);
 void	gmove(Node*, Node*);
 Prog*	gins(int, Node*, Node*);
 int	samaddr(Node*, Node*);

src/cmd/8g/cgen.c

@@ -1130,21 +1130,21 @@ stkof(Node *n)
  *	memmove(&res, &n, w);
  */
 void
-sgen(Node *n, Node *res, int32 w)
+sgen(Node *n, Node *res, int64 w)
 {
 	Node dst, src, tdst, tsrc;
 	int32 c, q, odst, osrc;
 
 	if(debug['g']) {
-		print("\nsgen w=%d\n", w);
+		print("\nsgen w=%ld\n", w);
 		dump("r", n);
 		dump("res", res);
 	}
 	if(n->ullman >= UINF && res->ullman >= UINF)
 		fatal("sgen UINF");
 
-	if(w < 0)
+	if(w < 0 || (int32)w != w)
-		fatal("sgen copy %d", w);
+		fatal("sgen copy %lld", w);
 
 	if(w == 0) {
 		// evaluate side effects only.

src/cmd/8g/gg.h

@@ -99,7 +99,7 @@ void	agenr(Node *n, Node *a, Node *res);
 void	igen(Node*, Node*, Node*);
 vlong	fieldoffset(Type*, Node*);
 void	bgen(Node*, int, Prog*);
-void	sgen(Node*, Node*, int32);
+void	sgen(Node*, Node*, int64);
 void	gmove(Node*, Node*);
 Prog*	gins(int, Node*, Node*);
 int	samaddr(Node*, Node*);

src/cmd/gc/align.c

@@ -285,6 +285,9 @@ dowidth(Type *t)
 		break;
 	}
 
+	if(widthptr == 4 && w != (int32)w)
+		yyerror("type %T too large", t);
+
 	t->width = w;
 	if(t->align == 0) {
 		if(w > 8 || (w&(w-1)) != 0)

src/cmd/gc/pgen.c

@@ -119,6 +119,10 @@ compile(Node *fn)
 	if(0)
 		print("allocauto: %lld to %lld\n", oldstksize, (vlong)stksize);
 
+	setlineno(curfn);
+	if(stksize+maxarg > (1ULL<<31))
+		yyerror("stack frame too large (>2GB)");
+
 	defframe(ptxt);
 
 	if(0)

test/fixedbugs/bug385_32.go

@@ -0,0 +1,14 @@
+// [ $O == 6 ] || errchk $G -e $D/$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.
+
+// Issue 2444
+
+package main
+func main() {
+	var arr [1000200030]int   // ERROR "type .* too large"
+	arr_bkup := arr
+	_ = arr_bkup
+}

test/fixedbugs/bug385_64.go

@@ -0,0 +1,15 @@
+// [ $O != 6 ]  || errchk $G -e $D/$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.
+
+// Issue 2444
+
+package main
+func main() {  // ERROR "stack frame too large"
+	var arr [1000200030]int
+	arr_bkup := arr
+	_ = arr_bkup
+}
+