cmd/compile: change dead code into assert
After fixing #13587, I noticed that the "OAS2FUNC in disguise" block
looked like it probably needed write barriers too. However, testing
revealed the multi-value "return f()" case was already being handled
correctly.
It turns out this block is dead code due to "return f()" already being
transformed into "t1, t2, ..., tN := f(); return t1, t2, ..., tN" by
orderstmt when f is a multi-valued function.
Updates #13587.
Change-Id: Icde46dccc55beda2ea5fd5fcafc9aae26cec1552
Reviewed-on: https://go-review.googlesource.com/17759
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go
index d4dc81a..25cd828 100644
--- a/src/cmd/compile/internal/gc/walk.go
+++ b/src/cmd/compile/internal/gc/walk.go
@@ -299,6 +299,12 @@
}
}
+ if got, want := count(n.List), count(rl); got != want {
+ // order should have rewritten multi-value function calls
+ // with explicit OAS2FUNC nodes.
+ Fatalf("expected %v return arguments, have %v", want, got)
+ }
+
if samelist(rl, n.List) {
// special return in disguise
n.List = nil
@@ -306,17 +312,6 @@
break
}
- if count(n.List) == 1 && count(rl) > 1 {
- // OAS2FUNC in disguise
- f := n.List.N
-
- if f.Op != OCALLFUNC && f.Op != OCALLMETH && f.Op != OCALLINTER {
- Fatalf("expected return of call, have %v", f)
- }
- n.List = concat(list1(f), ascompatet(n.Op, rl, &f.Type, 0, &n.Ninit))
- break
- }
-
// move function calls out, to make reorder3's job easier.
walkexprlistsafe(n.List, &n.Ninit)
