path: root/INSTALL
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authorJoseph Myers <joseph@codesourcery.com>2014-12-10 01:14:48 +0000
committerJoseph Myers <joseph@codesourcery.com>2014-12-10 01:14:48 +0000
commita4ecc9eb9b15bc51a1dc4726c06d35eaea74e162 (patch)
tree82641c7fc5034317ba20ca9a5a1063099de27766 /INSTALL
parent0f88636c09686b1f8e876bfa88b40bacbcae8c11 (diff)
Use -Werror by default, add --disable-werror.
As discussed starting at <https://sourceware.org/ml/libc-alpha/2014-11/msg00323.html>, this patch makes the glibc build use -Werror by default to avoid accidentally adding new warnings to the build. The configure option --disable-werror can be used to disable this. -Wno-error=undef is temporarily used because the build isn't clean regarding -Wundef warnings. The idea is that once the remaining -Wundef warnings have been cleaned up (in at least one configuration), -Wno-error=undef will be removed. I get a clean build and test on x86_64 (GCC 4.9 branch) with this patch. The expectation is that this may well break the build for some other configurations, and people seeing such breakage should make appropriate fixes to fix or suppress the warnings for their configurations. In some cases that may involve using pragmas as the right fix (I think that will be right for the -Wno-inline issue for MIPS I referred to in <https://sourceware.org/ml/libc-alpha/2012-11/msg00798.html>, for example), in some cases -Wno-error in sysdeps makefiles (__restore_rt in MIPS sigaction, for example), in some cases substantive fixes for the warnings. Note that if, with a view to listing all the warnings then fixing them all, you just look for "warning:" in output from building and testing with --disable-werror, you'll see lots of warnings from the linker about functions such as tmpnam. Those warnings can be ignored - only compiler warnings are relevant to -Werror, not linker warnings. * configure.ac (--disable-werror): New configure option. (enable_werror): New AC_SUBST. * configure: Regenerated. * config.make.in (enable-werror): New variable. * Makeconfig [$(enable-werror) = yes] (+gccwarn): Add -Werror -Wno-error=undef. (+gccwarn-c): Do not use -Werror=implicit-function-declaration. * manual/install.texi (Configuring and compiling): Document --disable-werror. * INSTALL: Regenerated. * debug/Makefile (CFLAGS-tst-chk1.c): Add -Wno-error. (CFLAGS-tst-chk2.c): Likewise. (CFLAGS-tst-chk3.c): Likewise. (CFLAGS-tst-chk4.cc): Likewise. (CFLAGS-tst-chk5.cc): Likewise. (CFLAGS-tst-chk6.cc): Likewise. (CFLAGS-tst-lfschk1.c): Likewise. (CFLAGS-tst-lfschk2.c): Likewise. (CFLAGS-tst-lfschk3.c): Likewise. (CFLAGS-tst-lfschk4.cc): Likewise. (CFLAGS-tst-lfschk5.cc): Likewise. (CFLAGS-tst-lfschk6.cc): Likewise.
Diffstat (limited to 'INSTALL')
1 files changed, 7 insertions, 0 deletions
diff --git a/INSTALL b/INSTALL
index dac6178baca..dd5c34aadb7 100644
@@ -143,6 +143,13 @@ will be used, and CFLAGS sets optimization options for the compiler.
additional security risks to the system and you should enable it
only if you understand and accept those risks.
+ By default, the GNU C Library is built with `-Werror'. If you wish
+ to build without this option (for example, if building with a newer
+ version of GCC than this version of the GNU C Library was tested
+ with, so new warnings cause the build with `-Werror' to fail), you
+ can configure with `--disable-werror'.
These options are for cross-compiling. If you specify both