From a4ecc9eb9b15bc51a1dc4726c06d35eaea74e162 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Wed, 10 Dec 2014 01:14:48 +0000 Subject: [PATCH] Use -Werror by default, add --disable-werror. As discussed starting at , 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 , 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 [$(enable-werror) = yes] (+gccwarn): Add -Werror -Wno-error=undef. (+gccwarn-c): Do not use -Werror=implicit-function-declaration. * manual/install.texi (Configuring and compiling): Document --disable-werror. * INSTALL: Regenerated. * debug/Makefile (CFLAGS-tst-chk1.c): Add -Wno-error. (CFLAGS-tst-chk2.c): Likewise. (CFLAGS-tst-chk3.c): Likewise. (CFLAGS-tst-chk4.cc): Likewise. (CFLAGS-tst-chk5.cc): Likewise. (CFLAGS-tst-chk6.cc): Likewise. (CFLAGS-tst-lfschk1.c): Likewise. (CFLAGS-tst-lfschk2.c): Likewise. (CFLAGS-tst-lfschk3.c): Likewise. (CFLAGS-tst-lfschk4.cc): Likewise. (CFLAGS-tst-lfschk5.cc): Likewise. (CFLAGS-tst-lfschk6.cc): Likewise. --- ChangeLog | 23 +++++++++++++++++++++++ INSTALL | 7 +++++++ Makeconfig | 5 ++++- NEWS | 3 +++ config.make.in | 1 + configure | 12 ++++++++++++ configure.ac | 7 +++++++ debug/Makefile | 28 +++++++++++++++------------- manual/install.texi | 7 +++++++ 9 files changed, 79 insertions(+), 14 deletions(-) diff --git a/ChangeLog b/ChangeLog index 1014ba3..f865223 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,28 @@ 2014-12-10 Joseph Myers + * configure.ac (--disable-werror): New configure option. + (enable_werror): New AC_SUBST. + * configure: Regenerated. + * config.make.in (enable-werror): New variable. + * Makeconfig [$(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. + * stdio-common/tst-printfsz.c: Include . (main): Disable -Wdeprecated-declarations around calls to register_printf_function. diff --git a/INSTALL b/INSTALL index dac6178..dd5c34a 100644 --- a/INSTALL +++ b/INSTALL @@ -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. +`--disable-werror' + 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'. + `--build=BUILD-SYSTEM' `--host=HOST-SYSTEM' These options are for cross-compiling. If you specify both diff --git a/Makeconfig b/Makeconfig index bbf5460..1555368 100644 --- a/Makeconfig +++ b/Makeconfig @@ -717,7 +717,10 @@ else +gccwarn := -Wall -Wwrite-strings -Winline endif +gccwarn += -Wundef -+gccwarn-c = -Wstrict-prototypes -Werror=implicit-function-declaration +ifeq ($(enable-werror),yes) ++gccwarn += -Werror -Wno-error=undef +endif ++gccwarn-c = -Wstrict-prototypes # We do not depend on the address of constants in different files to be # actually different, so allow the compiler to merge them all. diff --git a/NEWS b/NEWS index 1b08d40..2cc4a61 100644 --- a/NEWS +++ b/NEWS @@ -26,6 +26,9 @@ Version 2.21 C Library is GCC 4.6. Older GCC versions, and non-GNU compilers, can still be used to compile programs using the GNU C Library. +* The GNU C Library is now built with -Werror by default. This can be + disabled by configuring with --disable-werror. + * New locales: tu_IN, bh_IN, raj_IN, ce_RU. * The obsolete sigvec function has been removed. This was the original diff --git a/config.make.in b/config.make.in index 4a781fd..ad4dd30 100644 --- a/config.make.in +++ b/config.make.in @@ -45,6 +45,7 @@ sysheaders = @sysheaders@ sysincludes = @SYSINCLUDES@ c++-sysincludes = @CXX_SYSINCLUDES@ all-warnings = @all_warnings@ +enable-werror = @enable_werror@ have-z-combreloc = @libc_cv_z_combreloc@ have-z-execstack = @libc_cv_z_execstack@ diff --git a/configure b/configure index 0cb54ec..b1fda38 100755 --- a/configure +++ b/configure @@ -668,6 +668,7 @@ build_pt_chown build_nscd link_obsolete_rpc libc_cv_nss_crypt +enable_werror all_warnings force_install bindnow @@ -767,6 +768,7 @@ enable_force_install enable_maintainer_mode enable_kernel enable_all_warnings +enable_werror enable_multi_arch enable_nss_crypt enable_obsolete_rpc @@ -1428,6 +1430,7 @@ Optional Features: --enable-kernel=VERSION compile for compatibility with kernel not older than VERSION --enable-all-warnings enable all useful warnings gcc can issue + --disable-werror do not build with -Werror --enable-multi-arch enable single DSO with optimizations for multiple architectures --enable-nss-crypt enable libcrypt to use nss @@ -3565,6 +3568,15 @@ fi +# Check whether --enable-werror was given. +if test "${enable_werror+set}" = set; then : + enableval=$enable_werror; enable_werror=$enableval +else + enable_werror=yes +fi + + + # Check whether --enable-multi-arch was given. if test "${enable_multi_arch+set}" = set; then : enableval=$enable_multi_arch; multi_arch=$enableval diff --git a/configure.ac b/configure.ac index b2c4b1f..784e360 100644 --- a/configure.ac +++ b/configure.ac @@ -253,6 +253,13 @@ AC_ARG_ENABLE([all-warnings], []) AC_SUBST(all_warnings) +AC_ARG_ENABLE([werror], + AC_HELP_STRING([--disable-werror], + [do not build with -Werror]), + [enable_werror=$enableval], + [enable_werror=yes]) +AC_SUBST(enable_werror) + AC_ARG_ENABLE([multi-arch], AC_HELP_STRING([--enable-multi-arch], [enable single DSO with optimizations for multiple architectures]), diff --git a/debug/Makefile b/debug/Makefile index 3ddcd1e..96c21d5 100644 --- a/debug/Makefile +++ b/debug/Makefile @@ -96,19 +96,21 @@ CFLAGS-tst-longjmp_chk3.c = -fexceptions -fasynchronous-unwind-tables CPPFLAGS-tst-longjmp_chk3.c = -D_FORTIFY_SOURCE=1 # We know these tests have problems with format strings, this is what -# we are testing. Disable that warning. -CFLAGS-tst-chk1.c = -Wno-format -CFLAGS-tst-chk2.c = -Wno-format -CFLAGS-tst-chk3.c = -Wno-format -CFLAGS-tst-chk4.cc = -Wno-format -CFLAGS-tst-chk5.cc = -Wno-format -CFLAGS-tst-chk6.cc = -Wno-format -CFLAGS-tst-lfschk1.c = -Wno-format -CFLAGS-tst-lfschk2.c = -Wno-format -CFLAGS-tst-lfschk3.c = -Wno-format -CFLAGS-tst-lfschk4.cc = -Wno-format -CFLAGS-tst-lfschk5.cc = -Wno-format -CFLAGS-tst-lfschk6.cc = -Wno-format +# we are testing. Disable that warning. They also generate warnings +# from warning attributes, which cannot be disabled via pragmas, so +# require -Wno-error to be used. +CFLAGS-tst-chk1.c = -Wno-format -Wno-error +CFLAGS-tst-chk2.c = -Wno-format -Wno-error +CFLAGS-tst-chk3.c = -Wno-format -Wno-error +CFLAGS-tst-chk4.cc = -Wno-format -Wno-error +CFLAGS-tst-chk5.cc = -Wno-format -Wno-error +CFLAGS-tst-chk6.cc = -Wno-format -Wno-error +CFLAGS-tst-lfschk1.c = -Wno-format -Wno-error +CFLAGS-tst-lfschk2.c = -Wno-format -Wno-error +CFLAGS-tst-lfschk3.c = -Wno-format -Wno-error +CFLAGS-tst-lfschk4.cc = -Wno-format -Wno-error +CFLAGS-tst-lfschk5.cc = -Wno-format -Wno-error +CFLAGS-tst-lfschk6.cc = -Wno-format -Wno-error LDLIBS-tst-chk4 = -lstdc++ LDLIBS-tst-chk5 = -lstdc++ LDLIBS-tst-chk6 = -lstdc++ diff --git a/manual/install.texi b/manual/install.texi index 1eafb6e..35467b1 100644 --- a/manual/install.texi +++ b/manual/install.texi @@ -174,6 +174,13 @@ setuid and owned by @code{root}. The use of @file{pt_chown} introduces additional security risks to the system and you should enable it only if you understand and accept those risks. +@item --disable-werror +By default, @theglibc{} is built with @option{-Werror}. If you wish +to build without this option (for example, if building with a newer +version of GCC than this version of @theglibc{} was tested with, so +new warnings cause the build with @option{-Werror} to fail), you can +configure with @option{--disable-werror}. + @item --build=@var{build-system} @itemx --host=@var{host-system} These options are for cross-compiling. If you specify both options and -- 2.7.4