From 8c61286797664f445db424050ea4c73cf265b242 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Mon, 23 Nov 2015 21:17:45 +0000 Subject: [PATCH] re PR go/68496 ([libgo] reflect test fails on Linux x86-64) 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 From-SVN: r230776 --- gcc/go/gofrontend/MERGE | 2 +- libgo/runtime/go-reflect-call.c | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index 9ee3535a4f7..9fe9d5e1042 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 29e814a793f..2a14d6c6add 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; }