cmd/compile: fix race detector handling of OBLOCK nodes
Fixes #7561 correctly.
Fixes #9137.
Change-Id: I7f27e199d7101b785a7645f789e8fe41a405a86f
Reviewed-on: https://go-review.googlesource.com/11713
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
diff --git a/src/cmd/compile/internal/gc/racewalk.go b/src/cmd/compile/internal/gc/racewalk.go
index 2664e0c..a360c4d 100644
--- a/src/cmd/compile/internal/gc/racewalk.go
+++ b/src/cmd/compile/internal/gc/racewalk.go
@@ -147,27 +147,27 @@
goto ret
case OBLOCK:
- if n.List == nil {
- goto ret
+ var out *NodeList
+ for l := n.List; l != nil; l = l.Next {
+ switch l.N.Op {
+ case OCALLFUNC, OCALLMETH, OCALLINTER:
+ racewalknode(&l.N, &out, 0, 0)
+ out = list(out, l.N)
+ // Scan past OAS nodes copying results off stack.
+ // Those must not be instrumented, because the
+ // instrumentation calls will smash the results.
+ // The assignments are to temporaries, so they cannot
+ // be involved in races and need not be instrumented.
+ for l.Next != nil && l.Next.N.Op == OAS && iscallret(l.Next.N.Right) {
+ l = l.Next
+ out = list(out, l.N)
+ }
+ default:
+ racewalknode(&l.N, &out, 0, 0)
+ out = list(out, l.N)
+ }
}
-
- switch n.List.N.Op {
- // Blocks are used for multiple return function calls.
- // x, y := f() becomes BLOCK{CALL f, AS x [SP+0], AS y [SP+n]}
- // We don't want to instrument between the statements because it will
- // smash the results.
- case OCALLFUNC, OCALLMETH, OCALLINTER:
- racewalknode(&n.List.N, &n.List.N.Ninit, 0, 0)
-
- var fini *NodeList
- racewalklist(n.List.Next, &fini)
- n.List = concat(n.List, fini)
-
- // Ordinary block, for loop initialization or inlined bodies.
- default:
- racewalklist(n.List, nil)
- }
-
+ n.List = out
goto ret
case ODEFER:
