bpo-34121: Fix detection of C11 atomic support on clang. (GH-8288)

(cherry picked from commit 15c7b2a)

Co-authored-by: Benjamin Peterson <benjamin@python.org>

Misc/NEWS.d/next/Build/2018-07-15-16-49-06.bpo-34121.74G_lo.rst

@@ -0,0 +1 @@
+Fix detection of C11 atomic support on clang.

aclocal.m4

@@ -12,9 +12,9 @@
 # PARTICULAR PURPOSE.
 
 m4_ifndef([AC_CONFIG_MACRO_DIRS], [m4_defun([_AM_CONFIG_MACRO_DIRS], [])m4_defun([AC_CONFIG_MACRO_DIRS], [_AM_CONFIG_MACRO_DIRS($@)])])
-# pkg.m4 - Macros to locate and utilise pkg-config.   -*- Autoconf -*-
-# serial 12 (pkg-config-0.29.2)
-
+dnl pkg.m4 - Macros to locate and utilise pkg-config.   -*- Autoconf -*-
+dnl serial 11 (pkg-config-0.29.1)
+dnl
 dnl Copyright © 2004 Scott James Remnant <scott@netsplit.com>.
 dnl Copyright © 2012-2015 Dan Nicholson <dbn.lists@gmail.com>
 dnl
@@ -55,7 +55,7 @@ dnl
 dnl See the "Since" comment for each macro you use to see what version
 dnl of the macros you require.
 m4_defun([PKG_PREREQ],
-[m4_define([PKG_MACROS_VERSION], [0.29.2])
+[m4_define([PKG_MACROS_VERSION], [0.29.1])
 m4_if(m4_version_compare(PKG_MACROS_VERSION, [$1]), -1,
     [m4_fatal([pkg.m4 version $1 or higher is required but ]PKG_MACROS_VERSION[ found])])
 ])dnl PKG_PREREQ
@@ -156,7 +156,7 @@ AC_ARG_VAR([$1][_CFLAGS], [C compiler flags for $1, overriding pkg-config])dnl
 AC_ARG_VAR([$1][_LIBS], [linker flags for $1, overriding pkg-config])dnl
 
 pkg_failed=no
-AC_MSG_CHECKING([for $2])
+AC_MSG_CHECKING([for $1])
 
 _PKG_CONFIG([$1][_CFLAGS], [cflags], [$2])
 _PKG_CONFIG([$1][_LIBS], [libs], [$2])
@@ -166,11 +166,11 @@ and $1[]_LIBS to avoid the need to call pkg-config.
 See the pkg-config man page for more details.])
 
 if test $pkg_failed = yes; then
-        AC_MSG_RESULT([no])
+   	AC_MSG_RESULT([no])
         _PKG_SHORT_ERRORS_SUPPORTED
         if test $_pkg_short_errors_supported = yes; then
 	        $1[]_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "$2" 2>&1`
-        else
+        else 
 	        $1[]_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "$2" 2>&1`
         fi
 	# Put the nasty error message in config.log where it belongs
@@ -187,7 +187,7 @@ installed software in a non-standard prefix.
 _PKG_TEXT])[]dnl
         ])
 elif test $pkg_failed = untried; then
-        AC_MSG_RESULT([no])
+     	AC_MSG_RESULT([no])
 	m4_default([$4], [AC_MSG_FAILURE(
 [The pkg-config script could not be found or is too old.  Make sure it
 is in your PATH or set the PKG_CONFIG environment variable to the full

configure

@@ -781,6 +781,7 @@ infodir
 docdir
 oldincludedir
 includedir
+runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -892,6 +893,7 @@ datadir='${datarootdir}'
 sysconfdir='${prefix}/etc'
 sharedstatedir='${prefix}/com'
 localstatedir='${prefix}/var'
+runstatedir='${localstatedir}/run'
 includedir='${prefix}/include'
 oldincludedir='/usr/include'
 docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
@@ -1144,6 +1146,15 @@ do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
 
+  -runstatedir | --runstatedir | --runstatedi | --runstated \
+  | --runstate | --runstat | --runsta | --runst | --runs \
+  | --run | --ru | --r)
+    ac_prev=runstatedir ;;
+  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
+  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
+  | --run=* | --ru=* | --r=*)
+    runstatedir=$ac_optarg ;;
+
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1281,7 +1292,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir
+		libdir localedir mandir runstatedir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -1434,6 +1445,7 @@ Fine tuning of the installation directories:
   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
+  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
   --libdir=DIR            object code libraries [EPREFIX/lib]
   --includedir=DIR        C header files [PREFIX/include]
   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
@@ -16616,7 +16628,6 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 
     #include <stdatomic.h>
     atomic_int value = ATOMIC_VAR_INIT(1);
-    _Atomic void *py_atomic_address = (void*) &value;
     int main() {
       int loaded_value = atomic_load(&value);
       return 0;

configure.ac

@@ -5413,7 +5413,6 @@ AC_LINK_IFELSE(
   AC_LANG_SOURCE([[
     #include <stdatomic.h>
     atomic_int value = ATOMIC_VAR_INIT(1);
-    _Atomic void *py_atomic_address = (void*) &value;
     int main() {
       int loaded_value = atomic_load(&value);
       return 0;
@@ -5425,7 +5424,7 @@ AC_MSG_RESULT($have_stdatomic_h)
 
 if test "$have_stdatomic_h" = yes; then
     AC_DEFINE(HAVE_STD_ATOMIC, 1,
-              [Has stdatomic.h, atomic_int and _Atomic void* types work])
+              [Has stdatomic.h with atomic_int])
 fi
 
 # Check for GCC >= 4.7 __atomic builtins

pyconfig.h.in

@@ -960,7 +960,7 @@
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
-/* Has stdatomic.h, atomic_int and _Atomic void* types work */
+/* Has stdatomic.h with atomic_int */
 #undef HAVE_STD_ATOMIC
 
 /* Define to 1 if you have the `strdup' function. */