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Diffstat (limited to 'build/autoconf/compiler-opts.m4')
| -rw-r--r-- | build/autoconf/compiler-opts.m4 | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/build/autoconf/compiler-opts.m4 b/build/autoconf/compiler-opts.m4 new file mode 100644 index 0000000000..c4446771d0 --- /dev/null +++ b/build/autoconf/compiler-opts.m4 @@ -0,0 +1,176 @@ +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 + +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], +[ +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 "$MOZ_ASAN"; then + MOZ_NO_DEBUG_RTL=1 +fi + +AC_SUBST(MOZ_NO_DEBUG_RTL) + +if test -n "$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 +fi +]) + +dnl A high level macro for selecting compiler options. +AC_DEFUN([MOZ_COMPILER_OPTS], +[ + MOZ_DEBUGGING_OPTS + MOZ_RTTI + +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 ======================================================== + +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} && + $LLVM_OBJDUMP -t conftest${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 ======================================================== + +SANCOV= +if test -n "$LIBFUZZER"; then + case "$LIBFUZZER_FLAGS" in + *-fsanitize-coverage*|*-fsanitize=fuzzer*) + SANCOV=1 + ;; + esac +fi + +if test "$GNU_CC" -a "$GCC_USE_GNU_LD" -a -z "$DEVELOPER_OPTIONS" -a -z "$MOZ_PROFILE_GENERATE" -a -z "$SANCOV"; then + if test -n "$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.${ac_objext}; then + if test "`$PYTHON3 -m mozbuild.configure.check_debug_ranges conftest.${ac_objext} conftest.${ac_ext}`" = \ + "`$PYTHON3 -m mozbuild.configure.check_debug_ranges conftest${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 + +if test "$GNU_CC$CLANG_CC"; then + case "${OS_TARGET}" in + Darwin|WASI) + # It's the default on those targets, and clang complains about -pie + # being unused if passed. + ;; + *) + MOZ_PROGRAM_LDFLAGS="$MOZ_PROGRAM_LDFLAGS -pie" + ;; + esac +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 + +]) |