a70bc14b92
libfastjson is supposed to use the __sync_*4 atomic intrinsics, but alas
it is not using them because their ./configure decides they are not
available: it uses AC_TRY_RUN to check for them, and the default is to
decide they are not available, because of cross-compilation.
Besides, one of the source files was not including the generated
config.h, so even after fixing ./configure there was still a build
error.
The first patch is a backport from upstream to fix the missing
inclusion.
The second patch is switching AC_TRY_RUN over to AC_LINK_IFELSE, as the
only thing we're interested in is to check for the presence of the
atomic intrisics, and linking is enough for that.
Fixes:
http://autobuild.buildroot.org/results/192/1923d0b570adba494f83747a9610ea6ec35f5223/
http://autobuild.buildroot.org/results/23a/23ac0e742ed3a70ae4d038f8c9eadc23e708f671/
and many others...
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
87 lines
3.2 KiB
Diff
87 lines
3.2 KiB
Diff
From df087711cf7be55268a55e7820f4d928cb34c078 Mon Sep 17 00:00:00 2001
|
|
From: "Yann E. MORIN" <yann.morin.1998@free.fr>
|
|
Date: Sat, 9 Jul 2016 20:44:36 +0200
|
|
Subject: [PATCH] m4: fix detection of atomics
|
|
|
|
In cross-compilation, it is impossible to run code at configure time to
|
|
detect the target specifics.
|
|
|
|
As such, AC_TRY_RUN fails miserably to detect reliably that atomic
|
|
intrisics are present in a toolchain, and decides they are not just
|
|
because this is cross-compilation.
|
|
|
|
Instead of AC_TRY_RUN, use AC_LINK_IFELSE that does not need to actually
|
|
run code, since all we're interested in is whether the intrisics are
|
|
present (or not). Fix both the 32- and 64-bit variants, even if the
|
|
latter is not used currently.
|
|
|
|
Fixes build failures detected by the Buildroot autobuilders, like:
|
|
http://autobuild.buildroot.org/results/23a/23ac0e742ed3a70ae4d038f8c9eadc23e708f671/build-end.log
|
|
http://autobuild.buildroot.org/results/192/1923d0b570adba494f83747a9610ea6ec35f5223/build-end.log
|
|
|
|
and many other cases, espcially on architectures where such intrisics are
|
|
present, but where the toolchain does not have threads (and anyway, it
|
|
is much more efficient to use the intrisics rather than use mutexes).
|
|
|
|
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
|
|
---
|
|
Patch sent upstream:
|
|
https://github.com/rsyslog/libfastjson/pull/109
|
|
|
|
---
|
|
m4/atomic_operations.m4 | 6 ++----
|
|
m4/atomic_operations_64bit.m4 | 6 ++----
|
|
2 files changed, 4 insertions(+), 8 deletions(-)
|
|
|
|
diff --git a/m4/atomic_operations.m4 b/m4/atomic_operations.m4
|
|
index ad0ee60..7d2bca6 100644
|
|
--- a/m4/atomic_operations.m4
|
|
+++ b/m4/atomic_operations.m4
|
|
@@ -9,9 +9,7 @@
|
|
#
|
|
AC_DEFUN([RS_ATOMIC_OPERATIONS],
|
|
[AC_CACHE_CHECK([whether the compiler provides atomic builtins], [ap_cv_atomic_builtins],
|
|
-[AC_TRY_RUN([
|
|
-int main()
|
|
-{
|
|
+[AC_LINK_IFELSE([AC_LANG_PROGRAM([], [[
|
|
unsigned long val = 1010, tmp, *mem = &val;
|
|
|
|
if (__sync_fetch_and_add(&val, 1010) != 1010 || val != 2020)
|
|
@@ -44,7 +42,7 @@ int main()
|
|
return 1;
|
|
|
|
return 0;
|
|
-}], [ap_cv_atomic_builtins=yes], [ap_cv_atomic_builtins=no], [ap_cv_atomic_builtins=no])])
|
|
+]])], [ap_cv_atomic_builtins=yes], [ap_cv_atomic_builtins=no])])
|
|
|
|
if test "$ap_cv_atomic_builtins" = "yes"; then
|
|
AC_DEFINE(HAVE_ATOMIC_BUILTINS, 1, [Define if compiler provides atomic builtins])
|
|
diff --git a/m4/atomic_operations_64bit.m4 b/m4/atomic_operations_64bit.m4
|
|
index 9fbef0a..d01a977 100644
|
|
--- a/m4/atomic_operations_64bit.m4
|
|
+++ b/m4/atomic_operations_64bit.m4
|
|
@@ -9,9 +9,7 @@
|
|
#
|
|
AC_DEFUN([RS_ATOMIC_OPERATIONS_64BIT],
|
|
[AC_CACHE_CHECK([whether the compiler provides atomic builtins for 64 bit data types], [ap_cv_atomic_builtins_64],
|
|
-[AC_TRY_RUN([
|
|
-int main()
|
|
-{
|
|
+[AC_LINK_IFELSE([AC_LANG_PROGRAM([], [[
|
|
unsigned long long val = 1010, tmp, *mem = &val;
|
|
|
|
if (__sync_fetch_and_add(&val, 1010) != 1010 || val != 2020)
|
|
@@ -44,7 +42,7 @@ int main()
|
|
return 1;
|
|
|
|
return 0;
|
|
-}], [ap_cv_atomic_builtins_64=yes], [ap_cv_atomic_builtins_64=no], [ap_cv_atomic_builtins_64=no])])
|
|
+]])], [ap_cv_atomic_builtins_64=yes], [ap_cv_atomic_builtins_64=no])])
|
|
|
|
if test "$ap_cv_atomic_builtins_64" = "yes"; then
|
|
AC_DEFINE(HAVE_ATOMIC_BUILTINS64, 1, [Define if compiler provides 64 bit atomic builtins])
|
|
--
|
|
2.7.4
|
|
|