gecko-dev/build/autoconf/compiler-opts.m4

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dnl This Source Code Form is subject to the terms of the Mozilla Public
dnl License, v. 2.0. If a copy of the MPL was not distributed with this
dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.
dnl Add compiler specific options
AC_DEFUN([MOZ_DEFAULT_COMPILER],
[
dnl set DEVELOPER_OPTIONS early; MOZ_DEFAULT_COMPILER is usually the first non-setup directive
if test -z "$MOZILLA_OFFICIAL"; then
DEVELOPER_OPTIONS=1
fi
MOZ_ARG_ENABLE_BOOL(release,
[ --enable-release Build with more conservative, release engineering-oriented options.
This may slow down builds.],
DEVELOPER_OPTIONS=,
DEVELOPER_OPTIONS=1)
dnl Default to MSVC for win32 and gcc-4.2 for darwin
dnl ==============================================================
if test -z "$CROSS_COMPILE"; then
case "$target" in
*-mingw*)
if test -z "$CPP"; then CPP="$CC -E -nologo"; fi
if test -z "$CXXCPP"; then CXXCPP="$CXX -TP -E -nologo"; ac_cv_prog_CXXCPP="$CXXCPP"; fi
if test -z "$AS"; then
case "${target_cpu}" in
i*86)
AS=ml;
;;
x86_64)
AS=ml64;
;;
esac
fi
if test -z "$MIDL"; then MIDL=midl; fi
# need override this flag since we don't use $(LDFLAGS) for this.
if test -z "$HOST_LDFLAGS" ; then
HOST_LDFLAGS=" "
fi
;;
esac
fi
])
dnl ============================================================================
dnl C++ rtti
dnl We don't use it in the code, but it can be usefull for debugging, so give
dnl the user the option of enabling it.
dnl ============================================================================
AC_DEFUN([MOZ_RTTI],
[
MOZ_ARG_ENABLE_BOOL(cpp-rtti,
[ --enable-cpp-rtti Enable C++ RTTI ],
[ _MOZ_USE_RTTI=1 ],
[ _MOZ_USE_RTTI= ])
if test -z "$_MOZ_USE_RTTI"; then
if test "$GNU_CC"; then
CXXFLAGS="$CXXFLAGS -fno-rtti"
else
case "$target" in
*-mingw*)
CXXFLAGS="$CXXFLAGS -GR-"
esac
fi
fi
])
dnl ========================================================
dnl =
dnl = Debugging Options
dnl =
dnl ========================================================
AC_DEFUN([MOZ_DEBUGGING_OPTS],
[
if test -z "$MOZ_DEBUG" -o -n "$MOZ_ASAN"; then
MOZ_NO_DEBUG_RTL=1
fi
AC_SUBST(MOZ_NO_DEBUG_RTL)
MOZ_DEBUG_ENABLE_DEFS="DEBUG TRACING"
MOZ_ARG_WITH_STRING(debug-label,
[ --with-debug-label=LABELS
Define DEBUG_<value> for each comma-separated
value given.],
[ for option in `echo $withval | sed 's/,/ /g'`; do
MOZ_DEBUG_ENABLE_DEFS="$MOZ_DEBUG_ENABLE_DEFS DEBUG_${option}"
done])
if test -n "$MOZ_DEBUG"; then
if test -n "$COMPILE_ENVIRONMENT"; then
AC_MSG_CHECKING([for valid debug flags])
_SAVE_CFLAGS=$CFLAGS
CFLAGS="$CFLAGS $MOZ_DEBUG_FLAGS"
AC_TRY_COMPILE([#include <stdio.h>],
[printf("Hello World\n");],
_results=yes,
_results=no)
AC_MSG_RESULT([$_results])
if test "$_results" = "no"; then
AC_MSG_ERROR([These compiler flags are invalid: $MOZ_DEBUG_FLAGS])
fi
CFLAGS=$_SAVE_CFLAGS
fi
MOZ_DEBUG_DEFINES="$MOZ_DEBUG_ENABLE_DEFS"
else
MOZ_DEBUG_DEFINES="NDEBUG TRIMMED"
fi
AC_SUBST_LIST(MOZ_DEBUG_DEFINES)
])
dnl A high level macro for selecting compiler options.
AC_DEFUN([MOZ_COMPILER_OPTS],
[
MOZ_DEBUGGING_OPTS
MOZ_RTTI
if test "$CLANG_CXX"; then
## We disable return-type-c-linkage because jsval is defined as a C++ type but is
## returned by C functions. This is possible because we use knowledge about the ABI
## to typedef it to a C type with the same layout when the headers are included
## from C.
_WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wno-unknown-warning-option -Wno-return-type-c-linkage"
fi
if test -n "$DEVELOPER_OPTIONS"; then
MOZ_FORCE_GOLD=1
fi
MOZ_ARG_ENABLE_BOOL(gold,
[ --enable-gold Enable GNU Gold Linker when it is not already the default],
MOZ_FORCE_GOLD=1,
MOZ_FORCE_GOLD=
)
if test "$GNU_CC" -a -n "$MOZ_FORCE_GOLD"; then
dnl if the default linker is BFD ld, check if gold is available and try to use it
dnl for local builds only.
if $CC -Wl,--version 2>&1 | grep -q "GNU ld"; then
GOLD=$($CC -print-prog-name=ld.gold)
case "$GOLD" in
/*)
;;
*)
GOLD=$(which $GOLD)
;;
esac
if test -n "$GOLD"; then
mkdir -p $_objdir/build/unix/gold
rm -f $_objdir/build/unix/gold/ld
ln -s "$GOLD" $_objdir/build/unix/gold/ld
if $CC -B $_objdir/build/unix/gold -Wl,--version 2>&1 | grep -q "GNU gold"; then
LDFLAGS="$LDFLAGS -B $_objdir/build/unix/gold"
else
rm -rf $_objdir/build/unix/gold
fi
fi
fi
fi
if test "$GNU_CC"; then
if $CC $LDFLAGS -Wl,--version 2>&1 | grep -q "GNU ld"; then
LD_IS_BFD=1
fi
fi
AC_SUBST([LD_IS_BFD])
if test "$GNU_CC"; then
if test -z "$DEVELOPER_OPTIONS"; then
CFLAGS="$CFLAGS -ffunction-sections -fdata-sections"
CXXFLAGS="$CXXFLAGS -ffunction-sections -fdata-sections"
fi
CFLAGS="$CFLAGS -fno-math-errno"
CXXFLAGS="$CXXFLAGS -fno-exceptions -fno-math-errno"
fi
dnl ========================================================
dnl = Identical Code Folding
dnl ========================================================
MOZ_ARG_DISABLE_BOOL(icf,
[ --disable-icf Disable Identical Code Folding],
MOZ_DISABLE_ICF=1,
MOZ_DISABLE_ICF= )
if test "$GNU_CC" -a "$GCC_USE_GNU_LD" -a -z "$MOZ_DISABLE_ICF" -a -z "$DEVELOPER_OPTIONS"; then
AC_CACHE_CHECK([whether the linker supports Identical Code Folding],
LD_SUPPORTS_ICF,
[echo 'int foo() {return 42;}' \
'int bar() {return 42;}' \
'int main() {return foo() - bar();}' > conftest.${ac_ext}
# If the linker supports ICF, foo and bar symbols will have
# the same address
if AC_TRY_COMMAND([${CC-cc} -o conftest${ac_exeext} $LDFLAGS -Wl,--icf=safe -ffunction-sections conftest.${ac_ext} $LIBS 1>&2]) &&
test -s conftest${ac_exeext} &&
objdump -t conftest${ac_exeext} | awk changequote(<<, >>)'{a[<<$>>6] = <<$>>1} END {if (a["foo"] && (a["foo"] != a["bar"])) { exit 1 }}'changequote([, ]); then
LD_SUPPORTS_ICF=yes
else
LD_SUPPORTS_ICF=no
fi
rm -rf conftest*])
if test "$LD_SUPPORTS_ICF" = yes; then
_SAVE_LDFLAGS="$LDFLAGS -Wl,--icf=safe"
LDFLAGS="$LDFLAGS -Wl,--icf=safe -Wl,--print-icf-sections"
AC_TRY_LINK([], [],
[LD_PRINT_ICF_SECTIONS=-Wl,--print-icf-sections],
[LD_PRINT_ICF_SECTIONS=])
AC_SUBST([LD_PRINT_ICF_SECTIONS])
LDFLAGS="$_SAVE_LDFLAGS"
fi
fi
dnl ========================================================
dnl = Automatically remove dead symbols
dnl ========================================================
if test "$GNU_CC" -a "$GCC_USE_GNU_LD" -a -z "$DEVELOPER_OPTIONS"; then
if test -n "$MOZ_DEBUG_FLAGS"; then
dnl See bug 670659
AC_CACHE_CHECK([whether removing dead symbols breaks debugging],
GC_SECTIONS_BREAKS_DEBUG_RANGES,
[echo 'int foo() {return 42;}' \
'int bar() {return 1;}' \
'int main() {return foo();}' > conftest.${ac_ext}
if AC_TRY_COMMAND([${CC-cc} -o conftest.${ac_objext} $CFLAGS $MOZ_DEBUG_FLAGS -c conftest.${ac_ext} 1>&2]) &&
AC_TRY_COMMAND([${CC-cc} -o conftest${ac_exeext} $LDFLAGS $MOZ_DEBUG_FLAGS -Wl,--gc-sections conftest.${ac_objext} $LIBS 1>&2]) &&
test -s conftest${ac_exeext} -a -s conftest.${ac_objext}; then
if test "`$PYTHON -m mozbuild.configure.check_debug_ranges conftest.${ac_objext} conftest.${ac_ext}`" = \
"`$PYTHON -m mozbuild.configure.check_debug_ranges conftest${ac_exeext} conftest.${ac_ext}`"; then
GC_SECTIONS_BREAKS_DEBUG_RANGES=no
else
GC_SECTIONS_BREAKS_DEBUG_RANGES=yes
fi
else
dnl We really don't expect to get here, but just in case
GC_SECTIONS_BREAKS_DEBUG_RANGES="no, but it's broken in some other way"
fi
rm -rf conftest*])
if test "$GC_SECTIONS_BREAKS_DEBUG_RANGES" = no; then
DSO_LDOPTS="$DSO_LDOPTS -Wl,--gc-sections"
fi
else
DSO_LDOPTS="$DSO_LDOPTS -Wl,--gc-sections"
fi
fi
# bionic in Android < 4.1 doesn't support PIE
# On OSX, the linker defaults to building PIE programs when targetting OSX 10.7+,
# but not when targetting OSX < 10.7. OSX < 10.7 doesn't support running PIE
# programs, so as long as support for OSX 10.6 is kept, we can't build PIE.
# Even after dropping 10.6 support, MOZ_PIE would not be useful since it's the
# default (and clang says the -pie option is not used).
# On other Unix systems, some file managers (Nautilus) can't start PIE programs
if test -n "$gonkdir" && test "$ANDROID_VERSION" -ge 16; then
MOZ_PIE=1
else
MOZ_PIE=
fi
MOZ_ARG_ENABLE_BOOL(pie,
[ --enable-pie Enable Position Independent Executables],
MOZ_PIE=1,
MOZ_PIE= )
if test "$GNU_CC" -a -n "$MOZ_PIE"; then
AC_MSG_CHECKING([for PIE support])
_SAVE_LDFLAGS=$LDFLAGS
LDFLAGS="$LDFLAGS -pie"
AC_TRY_LINK(,,AC_MSG_RESULT([yes])
[MOZ_PROGRAM_LDFLAGS="$MOZ_PROGRAM_LDFLAGS -pie"],
AC_MSG_RESULT([no])
AC_MSG_ERROR([--enable-pie requires PIE support from the linker.]))
LDFLAGS=$_SAVE_LDFLAGS
fi
AC_SUBST(MOZ_PROGRAM_LDFLAGS)
dnl ASan assumes no symbols are being interposed, and when that happens,
dnl it's not happy with it. Unconveniently, since Firefox is exporting
dnl libffi symbols and Gtk+3 pulls system libffi via libwayland-client,
dnl system libffi interposes libffi symbols that ASan assumes are in
dnl libxul, so it barfs about buffer overflows.
dnl Using -Wl,-Bsymbolic ensures no exported symbol can be interposed.
if test -n "$GCC_USE_GNU_LD"; then
case "$LDFLAGS" in
*-fsanitize=address*)
LDFLAGS="$LDFLAGS -Wl,-Bsymbolic"
;;
esac
fi
])