cmd/gc: don't recurse infinitely when a recursive type references itself more than...

Fixes #9432

Change-Id: I08c92481afa7c7fac890aa780efc1cb2fabad528
Reviewed-on: https://go-review.googlesource.com/2115
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>

diff --git a/src/cmd/gc/align.c b/src/cmd/gc/align.c
index 29accd353867c1794b04433146b307b750665992..57daaa974558d6a4a7e57a47a1e278bdceef11e2 100644 (file)
--- a/src/cmd/gc/align.c
+++ b/src/cmd/gc/align.c
@@ -137,6 +137,11 @@ dowidth(Type *t)
                return;
        }
 
+       // break infinite recursion if the broken recursive type
+       // is referenced again
+       if(t->broke && t->width == 0)
+               return;
+
        // defer checkwidth calls until after we're done
        defercalc++;
 

diff --git a/test/fixedbugs/issue9432.go b/test/fixedbugs/issue9432.go
new file mode 100644 (file)
index 0000000..0d0bc96
--- /dev/null
+++ b/test/fixedbugs/issue9432.go
@@ -0,0 +1,15 @@
+// errorcheck
+
+// Copyright 2014 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.
+
+// gc used to recurse infinitely when dowidth is applied
+// to a broken recursive type again.
+// See golang.org/issue/9432.
+package p
+
+type foo struct { // GCCGO_ERROR "invalid recursive type"
+       bar  foo
+       blah foo
+} // ERROR "invalid recursive type foo"