runtime: adjust traceback / garbage collector boundary

The garbage collection routine addframeroots is duplicating
logic in the traceback routine that calls it, sometimes correctly,
sometimes incorrectly, sometimes incompletely.
Pass necessary information to addframeroots instead of
deriving it anew.

Should make addframeroots significantly more robust.
It's certainly smaller.

Also try to standardize on uintptr for saved pc, sp values.

Will make CL 10036044 trivial.

R=golang-dev, dave, dvyukov
CC=golang-dev
https://golang.org/cl/10169045

1 files changed, 7 insertions, 7 deletions

diff --git a/src/pkg/runtime/panic.c b/src/pkg/runtime/panic.c
index 18e4779540..b7075995f9 100644
--- a/src/pkg/runtime/panic.c
+++ b/src/pkg/runtime/panic.c
@@ -214,7 +214,7 @@ runtime·panic(Eface e)
 	p = runtime·mal(sizeof *p);
 	p->arg = e;
 	p->link = g->panic;
-	p->stackbase = (byte*)g->stackbase;
+	p->stackbase = g->stackbase;
 	g->panic = p;
 
 	for(;;) {
@@ -254,11 +254,11 @@ static void
 recovery(G *gp)
 {
 	void *argp;
-	void *pc;
+	uintptr pc;
 	
 	// Info about defer passed in G struct.
 	argp = (void*)gp->sigcode0;
-	pc = (void*)gp->sigcode1;
+	pc = (uintptr)gp->sigcode1;
 
 	// Unwind to the stack frame with d's arguments in it.
 	runtime·unwindstack(gp, argp);
@@ -292,12 +292,12 @@ runtime·unwindstack(G *gp, byte *sp)
 	if(g == gp)
 		runtime·throw("unwindstack on self");
 
-	while((top = (Stktop*)gp->stackbase) != nil && top->stackbase != nil) {
+	while((top = (Stktop*)gp->stackbase) != 0 && top->stackbase != 0) {
 		stk = (byte*)gp->stackguard - StackGuard;
 		if(stk <= sp && sp < (byte*)gp->stackbase)
 			break;
-		gp->stackbase = (uintptr)top->stackbase;
-		gp->stackguard = (uintptr)top->stackguard;
+		gp->stackbase = top->stackbase;
+		gp->stackguard = top->stackguard;
 		gp->stackguard0 = gp->stackguard;
 		if(top->free != 0)
 			runtime·stackfree(stk, top->free);
@@ -413,7 +413,7 @@ runtime·dopanic(int32 unused)
 		if(g != m->g0) {
 			runtime·printf("\n");
 			runtime·goroutineheader(g);
-			runtime·traceback(runtime·getcallerpc(&unused), runtime·getcallersp(&unused), 0, g);
+			runtime·traceback((uintptr)runtime·getcallerpc(&unused), (uintptr)runtime·getcallersp(&unused), 0, g);
 		}
 		if(!didothers) {
 			didothers = true;