Require GCC 4.6 or later to build glibc.

As discussed in the thread starting at
<https://sourceware.org/ml/libc-alpha/2014-10/msg00792.html>, and
continuing into November, this patch increases the minimum GCC version
for building glibc to 4.6 (there seemed to be no clear consensus for
4.7).  In particular, this allows us to use #pragma GCC diagnostic for
fine-grained warning control with -Werror (subject to establishing a
suitable policy for that use).  The documentation has a statement, as
requested, about the most recent GCC version tested for building
glibc, and I've updated <https://sourceware.org/glibc/wiki/Release> to
refer to updating that statement.  A NEWS entry is added for this
change, although previous such changes didn't get them.

Tested for x86_64 (testsuite, and that installed shared libraries are
unchanged by this patch).

	* configure.ac (libc_cv_compiler_ok): Require GCC 4.6 or later.
	* configure: Regenerated.
	* manual/install.texi (Tools for Compilation): Document a
	requirement of GCC 4.6 or later and that GCC 4.9 is the newest
	compiler verified to work.
	* INSTALL: Regenerated.

diff --git a/ChangeLog b/ChangeLog
index 8448f28f23376d2c57676ecf2245eed54f8f281b..496467e1c72fe64ac84caae063b7a6e4aa95912b 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2014-11-14  Joseph Myers  <joseph@codesourcery.com>
 
+       * configure.ac (libc_cv_compiler_ok): Require GCC 4.6 or later.
+       * configure: Regenerated.
+       * manual/install.texi (Tools for Compilation): Document a
+       requirement of GCC 4.6 or later and that GCC 4.9 is the newest
+       compiler verified to work.
+       * INSTALL: Regenerated.
+
        * include/string.h [NO_MEMPCPY_STPCPY_REDIRECT] (mempcpy): Do not
        redeclare with asm name.
        [NO_MEMPCPY_STPCPY_REDIRECT] (stpcpy): Likewise.

diff --git a/INSTALL b/INSTALL
index 3130c2a27cc8e1d19565649fa7809646bf40f254..dac6178bacac3df34f51f8c95c82af8e6acc3454 100644 (file)
--- a/INSTALL
+++ b/INSTALL
@@ -329,10 +329,13 @@ build the GNU C Library:
      recommend GNU `make' version 3.79.  All earlier versions have
      severe bugs or lack features.
 
-   * GCC 4.4 or newer, GCC 4.6 recommended
+   * GCC 4.6 or newer
 
-     GCC 4.4 or higher is required; as of this writing, GCC 4.6 is the
-     compiler we advise to use to build the GNU C Library.
+     GCC 4.6 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 4.9 is the newest compiler
+     verified to work to build the GNU C Library.
 
      You can use whatever compiler you like to compile programs that use
      the GNU C Library.

diff --git a/NEWS b/NEWS
index c582c8e559e71e3f8022a8a2ebc2264041c635a5..867d659afb869ac139350df0d008db7619a39bd8 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -14,6 +14,10 @@ Version 2.21
   17555, 17570, 17571, 17572, 17573, 17574, 17582, 17583, 17584, 17585,
   17589, 17594.
 
+* The minimum GCC version that can be used to build this version of the GNU
+  C Library is GCC 4.6.  Older GCC versions, and non-GNU compilers, can
+  still be used to compile programs using the GNU C Library.
+
 * New locales: tu_IN, bh_IN.
 \f
 Version 2.20

diff --git a/configure b/configure
index 3c161be38b2a7a80db021338c20e9e5781fbf067..0cb54ec363e43bed0feb8725a0360fbac91185a1 100755 (executable)
--- a/configure
+++ b/configure
@@ -4929,7 +4929,7 @@ int
 main ()
 {
 
-#if !defined __GNUC__ || __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 4)
+#if !defined __GNUC__ || __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
 #error insufficient compiler
 #endif
   ;

diff --git a/configure.ac b/configure.ac
index a982407d480f01cb10b4256b8f7286b01f4841a1..b2c4b1fab86e7c5438c8018b004be685380bb747 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -934,7 +934,7 @@ 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__ < 4)
+#if !defined __GNUC__ || __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
 #error insufficient compiler
 #endif],
               [libc_cv_compiler_ok=yes],

diff --git a/manual/install.texi b/manual/install.texi
index e1c2b9a2a49bac40d373f97b71ed3cf4762f1d6e..1eafb6ec322ce946357a911405f237a749dc138b 100644 (file)
--- a/manual/install.texi
+++ b/manual/install.texi
@@ -372,10 +372,13 @@ recommend GNU @code{make} version 3.79.  All earlier versions have severe
 bugs or lack features.
 
 @item
-GCC 4.4 or newer, GCC 4.6 recommended
+GCC 4.6 or newer
 
-GCC 4.4 or higher is required; as of this writing, GCC 4.6 is the
-compiler we advise to use to build @theglibc{}.
+GCC 4.6 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 4.9 is the newest compiler verified to work to build
+@theglibc{}.
 
 You can use whatever compiler you like to compile programs that use
 @theglibc{}.