libvirt/m4/virt-compile-warnings.m4
Matthias Bolte 9ba4eb3c08 tests: Lower stack usage below 4096 bytes
Make virtTestLoadFile allocate the buffer to read the file into.

Fix logic error in virtTestLoadFile, stop reading on the first empty line.

Use virFileReadLimFD in virtTestCaptureProgramOutput to avoid manual
buffer handling.
2011-04-30 19:59:52 +02:00

137 lines
5.1 KiB
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dnl
dnl Enable all known GCC compiler warnings, except for those
dnl we can't yet cope with
dnl
AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[
dnl ******************************
dnl More compiler warnings
dnl ******************************
AC_ARG_ENABLE(compile-warnings,
[AC_HELP_STRING([--enable-compile-warnings=@<:@no/yes/error@:>@],
[Turn on compiler warnings])],,
[enable_compile_warnings="m4_default([$1],[yes])"])
case "$enable_compile_warnings" in
no)
try_compiler_flags=""
;;
yes|minimum|maximum|error)
# List of warnings that are not relevant / wanted
# Don't care about C++ compiler compat
dontwarn="$dontwarn -Wc++-compat"
# Don't care about ancient C standard compat
dontwarn="$dontwarn -Wtraditional"
# Don't care about ancient C standard compat
dontwarn="$dontwarn -Wtraditional-conversion"
# Ignore warnings in /usr/include
dontwarn="$dontwarn -Wsystem-headers"
# Happy for compiler to add struct padding
dontwarn="$dontwarn -Wpadded"
# GCC very confused with -O2
dontwarn="$dontwarn -Wunreachable-code"
# Too many to deal with
dontwarn="$dontwarn -Wconversion"
# Too many to deal with
dontwarn="$dontwarn -Wsign-conversion"
# GNULIB gettext.h violates
dontwarn="$dontwarn -Wvla"
# Many GNULIB header violations
dontwarn="$dontwarn -Wundef"
# Need to allow bad cast for execve()
dontwarn="$dontwarn -Wcast-qual"
# We need to use long long in many places
dontwarn="$dontwarn -Wlong-long"
# We allow manual list of all enum cases without default:
dontwarn="$dontwarn -Wswitch-default"
# We allow optional default: instead of listing all enum values
dontwarn="$dontwarn -Wswitch-enum"
# Not a problem since we don't use -fstrict-overflow
dontwarn="$dontwarn -Wstrict-overflow"
# Not a problem since we don't use -funsafe-loop-optimizations
dontwarn="$dontwarn -Wunsafe-loop-optimizations"
# Things like virAsprintf mean we can't use this
dontwarn="$dontwarn -Wformat-nonliteral"
# We might fundamentally need some of these disabled forever, but ideally
# we'd turn many of them on
dontwarn="$dontwarn -Wfloat-equal"
dontwarn="$dontwarn -Wdeclaration-after-statement"
dontwarn="$dontwarn -Wcast-qual"
dontwarn="$dontwarn -Wconversion"
dontwarn="$dontwarn -Wsign-conversion"
dontwarn="$dontwarn -Wpacked"
dontwarn="$dontwarn -Wunused-macros"
dontwarn="$dontwarn -Woverlength-strings"
dontwarn="$dontwarn -Wstack-protector"
# Get all possible GCC warnings
gl_MANYWARN_ALL_GCC([maybewarn])
# Remove the ones we don't want, blacklisted earlier
gl_MANYWARN_COMPLEMENT([wantwarn], [$maybewarn], [$dontwarn])
# Check for $CC support of each warning
for w in $wantwarn; do
gl_WARN_ADD([$w])
done
# GNULIB uses '-W' (aka -Wextra) which includes a bunch of stuff.
# Unfortunately, this means you can't simply use '-Wsign-compare'
# with gl_MANYWARN_COMPLEMENT
# So we have -W enabled, and then have to explicitly turn off...
gl_WARN_ADD([-Wno-sign-compare])
# GNULIB expects this to be part of -Wc++-compat, but we turn
# that one off, so we need to manually enable this again
gl_WARN_ADD([-Wjump-misses-init])
# This should be < 256 really. Currently we're down to 4096,
# but using 1024 bytes sized buffers (mostly for virStrerror)
# stops us from going down further
gl_WARN_ADD([-Wframe-larger-than=4096])
dnl gl_WARN_ADD([-Wframe-larger-than=256])
# Extra special flags
gl_WARN_ADD([-Wp,-D_FORTIFY_SOURCE=2])
dnl -fstack-protector stuff passes gl_WARN_ADD with gcc
dnl on Mingw32, but fails when actually used
case $host in
*-*-linux*)
dnl Fedora only uses -fstack-protector, but doesn't seem to
dnl be great overhead in adding -fstack-protector-all instead
dnl gl_WARN_ADD([-fstack-protector])
gl_WARN_ADD([-fstack-protector-all])
gl_WARN_ADD([--param=ssp-buffer-size=4])
;;
esac
gl_WARN_ADD([-fexceptions])
gl_WARN_ADD([-fasynchronous-unwind-tables])
gl_WARN_ADD([-fdiagnostics-show-option])
gl_WARN_ADD([-funit-at-a-time])
if test "$enable_compile_warnings" = "error"
then
gl_WARN_ADD([-Werror])
fi
;;
*)
AC_MSG_ERROR(Unknown argument '$enable_compile_warnings' to --enable-compile-warnings)
;;
esac
WARN_LDFLAGS=$WARN_CFLAGS
AC_SUBST([WARN_CFLAGS])
AC_SUBST([WARN_LDFLAGS])
dnl Needed to keep compile quiet on python 2.4
save_WARN_CFLAGS=$WARN_CFLAGS
WARN_CFLAGS=
gl_WARN_ADD([-Wno-redundant-decls])
WARN_PYTHON_CFLAGS=$WARN_CFLAGS
AC_SUBST(WARN_PYTHON_CFLAGS)
WARN_CFLAGS=$save_WARN_CFLAGS
])