1From de870d7f9f36b3e68f280057851a4585a67ab219 Mon Sep 17 00:00:00 2001
2From: Sergei Trofimovich <slyfox@gentoo.org>
3Date: Tue, 14 Jan 2020 23:15:01 +0000
4Subject: [PATCH] ei_portio.h: avoid ODR violation of
5 'ei_default_socket_callbacks'
6
7Noticed as a build failure against fresh gcc-master:
8
9```
10LD otp/lib/erl_interface/bin/x86_64-unknown-linux-gnu/erl_call
11ld: otp/lib/erl_interface/obj/x86_64-unknown-linux-gnu/libei.a(eirecv.o):otp/lib/erl_interface/src/misc/ei_portio.h:50: multiple definition of `ei_default_socket_callbacks'; otp/lib/erl_interface/obj/x86_64-unknown-linux-gnu/libei.a(ei_connect.o):otp/lib/erl_interface/src/misc/ei_portio.h:50: first defined here
12ld: otp/lib/erl_interface/obj/x86_64-unknown-linux-gnu/libei.a(send.o):otp/lib/erl_interface/src/misc/ei_portio.h:50: multiple definition of `ei_default_socket_callbacks'; otp/lib/erl_interface/obj/x86_64-unknown-linux-gnu/libei.a(ei_connect.o):otp/lib/erl_interface/src/misc/ei_portio.h:50: first defined here
13ld: otp/lib/erl_interface/obj/x86_64-unknown-linux-gnu/libei.a(send_reg.o):otp/lib/erl_interface/src/misc/ei_portio.h:50: multiple definition of `ei_default_socket_callbacks'; otp/lib/erl_interface/obj/x86_64-unknown-linux-gnu/libei.a(ei_connect.o):otp/lib/erl_interface/src/misc/ei_portio.h:50: first defined here
14ld: otp/lib/erl_interface/obj/x86_64-unknown-linux-gnu/libei.a(epmd_port.o):otp/lib/erl_interface/src/misc/ei_portio.h:50: multiple definition of `ei_default_socket_callbacks'; otp/lib/erl_interface/obj/x86_64-unknown-linux-gnu/libei.a(ei_connect.o):otp/lib/erl_interface/src/misc/ei_portio.h:50: first defined here
15ld: otp/lib/erl_interface/obj/x86_64-unknown-linux-gnu/libei.a(ei_portio.o):otp/lib/erl_interface/src/misc/ei_portio.h:50: multiple definition of `ei_default_socket_callbacks'; otp/lib/erl_interface/obj/x86_64-unknown-linux-gnu/libei.a(ei_connect.o):otp/lib/erl_interface/src/misc/ei_portio.h:50: first defined here
16collect2: error: ld returned 1 exit status
17make[3]: *** [x86_64-unknown-linux-gnu/Makefile:669: otp/lib/erl_interface/bin/x86_64-unknown-linux-gnu/erl_call] Error 1
18```
19
20The failure looks legitimate: `ei_default_socket_callbacks` is a
21struct defined in 'ei_portio.h' and in 'ei_portio.c'.
22
23The change flips 'ei_portio.h' definition to declaration.
24
25gcc-10 will change the default from -fcommon to fno-common:
26https://gcc.gnu.org/PR85678.
27
28The error also happens if CFLAGS=-fno-common passed explicitly.
29
30Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
31
32Patch taken from upstream: https://github.com/erlang/otp/commit/de870d7f9f36b3e68f280057851a4585a67ab219
33Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
34---
35 lib/erl_interface/src/misc/ei_portio.h | 2 +-
36 1 file changed, 1 insertion(+), 1 deletion(-)
37
38diff --git a/lib/erl_interface/src/misc/ei_portio.h b/lib/erl_interface/src/misc/ei_portio.h
39index 84ebc5039a..5172d085b4 100644
40
41--- a/lib/erl_interface/src/misc/ei_portio.h
42+++ b/lib/erl_interface/src/misc/ei_portio.h
43@@ -47,7 +47,7 @@ int ei_writev_fill_ctx_t__(ei_socket_callbacks *cbs, void *ctx, const struct iov
44 int ei_socket_callbacks_have_writev__(ei_socket_callbacks *cbs);
45 #endif
46
47-ei_socket_callbacks ei_default_socket_callbacks;
48+extern ei_socket_callbacks ei_default_socket_callbacks;
49
50 #define EI_FD_AS_CTX__(FD)                                              \
51     ((void *) (long) (FD))
52--
532.20.1
54
55