Require GCC 4.9 or later for building glibc.

This patch makes configure require GCC 4.9 or later for building
glibc, and documents that requirement.  Requiring GCC 4.9 or later
allows use of _Generic (as in tzcode).  It would allow <stdatomic.h>
and _Atomic to be used as well if desired, although we need to avoid
any libatomic dependencies on any platforms.  This patch is explicitly
the minimum to implement a new version requirement, with any
consequent cleanups of conditional code (not in installed headers or
files shared with gnulib etc.) to be done separately.

Tested for x86_64.

	* configure.ac (libc_cv_compiler_ok): Require GCC 4.9 or later.
	* configure: Regenerated.
	* manual/install.texi (Tools for Compilation): Document
	requirement for GCC 4.9 or later.
	* INSTALL: Regenerated.

diff --git a/ChangeLog b/ChangeLog
index 3b61f167d2271aee2d920a7fd7071a4aa464ff43..b3d39a23fdc3b1271e80edcf50dc1a419eddb558 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2017-06-19  Joseph Myers  <joseph@codesourcery.com>
+
+       * configure.ac (libc_cv_compiler_ok): Require GCC 4.9 or later.
+       * configure: Regenerated.
+       * manual/install.texi (Tools for Compilation): Document
+       requirement for GCC 4.9 or later.
+       * INSTALL: Regenerated.
+
 2017-06-19  Florian Weimer  <fweimer@redhat.com>
 
        [BZ #21624]

diff --git a/INSTALL b/INSTALL
index a2f5a40b1740d9899502798458ad274bb92e1b57..71af35b1eb14203d24007226a169e6ddc1f3b78f 100644 (file)
--- a/INSTALL
+++ b/INSTALL
@@ -420,9 +420,9 @@ build the GNU C Library:
      recommend GNU 'make' version 3.79.  All earlier versions have
      severe bugs or lack features.
 
-   * GCC 4.7 or newer
+   * GCC 4.9 or newer
 
-     GCC 4.7 or higher is required.  In general it is recommended to use
+     GCC 4.9 or higher is required.  In general it is recommended to use
      the newest version of the compiler that is known to work for
      building the GNU C Library, as newer compilers usually produce
      better code.  As of release time, GCC 6.3 is the newest compiler

diff --git a/NEWS b/NEWS
index 9ee22185e8be62748a67c74a19122860e36fb097..f81d02f1cb5ddfbbc8185f55629c6eca39cec3e0 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -107,6 +107,10 @@ Version 2.26
   PTRACE_DISABLE_TE and PTRACE_TE_ABORT_RAND were added as those are supported
   by the s390 kernel.
 
+* The minimum GCC version that can be used to build this version of the GNU
+  C Library is GCC 4.9.  Older GCC versions, and non-GNU compilers, can
+  still be used to compile programs using the GNU C Library.
+
 Security related changes:
 
 * The DNS stub resolver limits the advertised UDP buffer size to 1200 bytes,

diff --git a/configure b/configure
index 8390f2b86e3c8752330a9624613f43ed2675a282..97a2dadf2dd8c451b5da0409043cbe2144c6b847 100755 (executable)
--- a/configure
+++ b/configure
@@ -5058,7 +5058,7 @@ int
 main ()
 {
 
-#if !defined __GNUC__ || __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
+#if !defined __GNUC__ || __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 9)
 #error insufficient compiler
 #endif
   ;

diff --git a/configure.ac b/configure.ac
index 4c0a18edd95e749a9f0138f961605f4a77d0d1a4..16e97d3930b8adaf3f134bb60ed70d68e1131c94 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1105,7 +1105,7 @@ AC_CHECK_PROG_VER(AWK, gawk, --version,
 
 AC_CACHE_CHECK([if $CC is sufficient to build libc], libc_cv_compiler_ok, [
 AC_TRY_COMPILE([], [
-#if !defined __GNUC__ || __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
+#if !defined __GNUC__ || __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 9)
 #error insufficient compiler
 #endif],
               [libc_cv_compiler_ok=yes],

diff --git a/manual/install.texi b/manual/install.texi
index cbc912817aa61d1c7d395512dfdc573f968fd350..65174a8b2ec734a663ee00968f7fb7c6b92bbfcc 100644 (file)
--- a/manual/install.texi
+++ b/manual/install.texi
@@ -467,9 +467,9 @@ recommend GNU @code{make} version 3.79.  All earlier versions have severe
 bugs or lack features.
 
 @item
-GCC 4.7 or newer
+GCC 4.9 or newer
 
-GCC 4.7 or higher is required.  In general it is recommended to use
+GCC 4.9 or higher is required.  In general it is recommended to use
 the newest version of the compiler that is known to work for building
 @theglibc{}, as newer compilers usually produce better code.  As of
 release time, GCC 6.3 is the newest compiler verified to work to build