From: ian <ian@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 23 Nov 2015 21:17:45 +0000 (+0000)
Subject: 	PR go/68496
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f76989fd5952e76492eba1999561c8714cca582c;p=thirdparty%2Fgcc.git

	PR go/68496
    reflect: Allocate space for FFI functions returning a zero-sized type.

    The libffi library does not understand zero-sized types.  We represent
    them as a struct with a single field of type void.  If such a type is
    returned from a function, libffi will copy 1 byte of data.  Allocate
    space for that byte, although we won't use it.

    Fixes https://gcc.gnu.org/PR68496.

    Reviewed-on: https://go-review.googlesource.com/17175


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@230776 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index 9ee3535a4f7b..9fe9d5e1042d 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-97ec885c715b3922b0866c081554899b8d50933a
+0d979f0b860cfd879754150e0ae5e1018b94d7c4
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/libgo/runtime/go-reflect-call.c b/libgo/runtime/go-reflect-call.c
index 29e814a793f6..2a14d6c6addd 100644
--- a/libgo/runtime/go-reflect-call.c
+++ b/libgo/runtime/go-reflect-call.c
@@ -81,6 +81,12 @@ go_results_size (const struct __go_func_type *func)
 
   off = (off + maxalign - 1) & ~ (maxalign - 1);
 
+  // The libffi library doesn't understand a struct with no fields.
+  // We generate a struct with a single field of type void.  When used
+  // as a return value, libffi will think that requires a byte.
+  if (off == 0)
+    off = 1;
+
   return off;
 }