gmp: Use __gnu_inline__ attribute in 4.2.1

gcc 5 defaults to C11 rules about "extern inline": this breaks
any code that includes gmp.h header from gmp 4.2.1 with 'multiple
definition' errors.

disable-stdc patch is no longer required because of this.

(From OE-Core rev: e03d95d70f8bfe57c258d270ac6b3331650dbc10)

Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/gmp/gmp-4.2.1/Use-__gnu_inline__-attribute.patch

@@ -0,0 +1,36 @@
+From 3cb33502bafd04b8ad4ca3454fab16d5ff313297 Mon Sep 17 00:00:00 2001
+From: Jussi Kukkonen <jussi.kukkonen@intel.com>
+Date: Tue, 22 Sep 2015 13:16:23 +0300
+Subject: [PATCH]  Use __gnu_inline__ attribute
+
+gcc5 uses C11 inline rules. This means the old "extern inline"
+semantics are not available without a special attribute.
+
+See: https://gcc.gnu.org/gcc-5/porting_to.html
+
+Upstream-Status: Inappropriate [Fixed in current versions]
+Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
+---
+ gmp-h.in | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/gmp-h.in b/gmp-h.in
+index eed6fe4..361dd1d 100644
+--- a/gmp-h.in
++++ b/gmp-h.in
+@@ -419,8 +419,11 @@ typedef __mpq_struct *mpq_ptr;
+ /* gcc has __inline__ in all modes, including strict ansi.  Give a prototype
+    for an inline too, so as to correctly specify "dllimport" on windows, in
+    case the function is called rather than inlined.  */
++
++/* Use __gnu_inline__ attribute: later gcc uses different "extern inline"
++   behaviour */
+ #ifdef __GNUC__
+-#define __GMP_EXTERN_INLINE      extern __inline__
++#define __GMP_EXTERN_INLINE      extern __inline__ __attribute__ ((__gnu_inline__))
+ #define __GMP_INLINE_PROTOTYPES  1
+ #endif
+ 
+-- 
+2.1.4
+

meta/recipes-support/gmp/gmp-4.2.1/disable-stdc.patch

@@ -1,39 +0,0 @@
-This patch was removed in f181c6ce8b3 when gmp 4.2.1 was mistakenly
-dropped.
-
-Upstream is not interested in patches for ancient versions.
-
-Upstream-Status: Inappropriate
-Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
-
-# "extern inline" in traditional gcc means that the function should be 
-# inlined wherever it's seen, while in C99, "extern inline" means that i
-# the function should only be inlined where the inline definition is 
-# seen while in other places it's not inlined:
-# http://gcc.gnu.org/ml/gcc/2006-11/msg00006.html
-#
-# gmp checks "--std=gnu99" to use C99 convention however it internally 
-# defines some "extern inline" functions in gmp.h, which is included
-# by mainly .c files and finally lead a flood of redefinition function
-# errors when linking objects together.
-#
-# So disable C99/ANSI detection to stick to tranditional gcc behavior
-#
-# by Kevin Tian <kevin.tian@intel.com>, 2010-08-13
-#
-# (this patch is licensed under GPLv2+)
-
-diff --git a/configure.in b/configure.in
-index 450cc92..aab0b59 100644
---- a/configure.in
-+++ b/configure.in
-@@ -1869,9 +1869,7 @@ AC_SUBST(DEFN_LONG_LONG_LIMB)
- 
- # The C compiler and preprocessor, put into ANSI mode if possible.
- AC_PROG_CC
--AC_PROG_CC_STDC
- AC_PROG_CPP
--GMP_H_ANSI
- 
- 
- # The C compiler on the build system, and associated tests.

meta/recipes-support/gmp/gmp_4.2.1.bb

@@ -7,7 +7,7 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=892f569a555ba9c07a568a7c0c4fa63a \
                     file://COPYING.LIB;md5=fbc093901857fcd118f065f900982c24 \
                     file://gmp-h.in;beginline=6;endline=21;md5=e056f74a12c3277d730dbcfb85d2ca34"
 
-SRC_URI += "file://disable-stdc.patch \
+SRC_URI += "file://Use-__gnu_inline__-attribute.patch \
             file://gmp_fix_for_automake-1.12.patch \
             "