cmd/compile: fix uninitialized memory during type switch assertE2I2
Fixes arm64 builder crash.
The bug is possible on all architectures; you just have to get lucky
and hit a preemption or a stack growth on entry to assertE2I2.
The test stacks the deck.
Change-Id: I8419da909b06249b1ad15830cbb64e386b6aa5f6
Reviewed-on: https://go-review.googlesource.com/12890
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/cmd/compile/internal/gc/swt.go b/src/cmd/compile/internal/gc/swt.go
index a736208..f34b1c6 100644
--- a/src/cmd/compile/internal/gc/swt.go
+++ b/src/cmd/compile/internal/gc/swt.go
@@ -652,6 +652,9 @@
} else {
name = t.Rlist.N
init = list1(Nod(ODCL, name, nil))
+ a := Nod(OAS, name, nil)
+ typecheck(&a, Etop)
+ init = list(init, a)
}
a := Nod(OAS2, nil, nil)
