From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2140) id D4DEC3849AF7; Fri, 19 Apr 2024 13:15:29 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D4DEC3849AF7 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1713532529; bh=yuSvHcOa4CcxmYtyI8xTtMTdbiiPTAaSdDD28MTbqoQ=; h=From:To:Subject:Date:From; b=BIghV88TONu75MzO/RX73cUnpJri6y1UIX6hvUzw75+5AGx0CcAbTA8D1ua7rjzGU FrdN0/8IjNNcK/DO6uC9ti5ZXn2UTFVrfnoO4pHDIrlBMSndf+kbX9uzuQXD/4Gyyr W4MQxmbLkfsPe0IFgWd4/hR1/3pyJi2+qnz9mtt4= MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="utf-8" From: Alexandre Oliva To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc(refs/users/aoliva/heads/testme)] [libstdc++] introduce --disable-compat-libstdcxx-abi X-Act-Checkin: gcc X-Git-Author: Alexandre Oliva X-Git-Refname: refs/users/aoliva/heads/testme X-Git-Oldrev: 694fa3717a908317e895543d949eb7180911615a X-Git-Newrev: 4c6efa350d11a66674d85046cc7b7cbc69f6dbe1 Message-Id: <20240419131529.D4DEC3849AF7@sourceware.org> Date: Fri, 19 Apr 2024 13:15:29 +0000 (GMT) List-Id: https://gcc.gnu.org/g:4c6efa350d11a66674d85046cc7b7cbc69f6dbe1 commit 4c6efa350d11a66674d85046cc7b7cbc69f6dbe1 Author: Alexandre Oliva Date: Tue Apr 16 01:26:20 2024 -0300 [libstdc++] introduce --disable-compat-libstdcxx-abi A number of libstdc++ tests that implicitly instantiate __to_chars_i and also link floating_to_chars.o in fail on vxworks kernel mode. The platform doesn't support undefweak symbols (the kernel module loader fails to load modules containing them), and because creating such modules doesn't involve final linking, only -r linking. The vague-linkage weak defs with abi-v2 mangling that get discarded from floating_to_chars.o because the same comdat section is present in the main executable. But since the alternate mangling is not defined in the main executable, the weak definition decays to a weak undefined symbol in the partially-linked kernel module, and then the kernel module loader barfs. Since our vxworks toolchains have little use for the compat ABI symbols, I thought we could work around this problem by getting rid of them. Absent a configure option to control that, I added one. for libstdc++-v3/ChangeLog * acinclude.m4 (GLIBCXX_EXPORT_FLAGS): Split -Wabi=2... (GLIBCXX_ENABLE_WABI): ... here. Control it with newly added --disable-compat-libstdcxx-abi. * configure: Rebuilt. * doc/html/manual/configure.html: Document it. Diff: --- libstdc++-v3/acinclude.m4 | 26 ++++++++++++++- libstdc++-v3/configure | 49 +++++++++++++++++++++++------ libstdc++-v3/doc/html/manual/configure.html | 4 ++- libstdc++-v3/doc/xml/manual/configure.xml | 4 +++ 4 files changed, 72 insertions(+), 11 deletions(-) diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4 index 51a08bcc8b1..2dd5aa2af89 100644 --- a/libstdc++-v3/acinclude.m4 +++ b/libstdc++-v3/acinclude.m4 @@ -707,10 +707,34 @@ AC_DEFUN([GLIBCXX_EXPORT_FLAGS], [ # OPTIMIZE_CXXFLAGS = -O3 -fstrict-aliasing -fvtable-gc AC_SUBST(OPTIMIZE_CXXFLAGS) - WARN_FLAGS="-Wall -Wextra -Wwrite-strings -Wcast-qual -Wabi=2" + WARN_FLAGS="-Wall -Wextra -Wwrite-strings -Wcast-qual" AC_SUBST(WARN_FLAGS) + + GLIBCXX_ENABLE_WABI ]) +dnl +dnl Enable -Wabi=2 if not overridden by --disable-compat-libstdcxx-abi. +dnl +AC_DEFUN([GLIBCXX_ENABLE_WABI], [ + # Default. + WARN_FLAGS_WABI=\ -Wabi=2 + AC_MSG_CHECKING([for --disable-compat-libstdcxx-abi-mangling]) + AC_ARG_ENABLE([compat-libstdcxx-abi-mangling], + AC_HELP_STRING([--disable-compat-libstdcxx-abi-mangling], + [Disable backward-compatibility mangling ABI symbols]), + [case "$enableval" in + yes) AC_MSG_RESULT(enabled$WARN_FLAGS_WABI) ;; + no) WARN_FLAGS_WABI= + AC_MSG_RESULT(disabled) ;; + *) AC_MSG_RESULT(unsupported) + AC_MSG_ERROR([Unsupported argument to enable/disable compat libstdc++ abi mangling]);; + esac], [ + AC_MSG_RESULT(defaulting to enabled$WARN_FLAGS_WABI) + ]) + + WARN_FLAGS="$WARN_FLAGS$WARN_FLAGS_WABI" +]) dnl dnl All installation directory information is determined here. diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure index 21abaeb0778..af03d5f96f4 100755 --- a/libstdc++-v3/configure +++ b/libstdc++-v3/configure @@ -973,6 +973,7 @@ enable_cet with_gxx_include_dir enable_version_specific_runtime_libs with_toolexeclibdir +enable_compat_libstdcxx_abi_mangling with_gcc_major_version_only ' ac_precious_vars='build_alias @@ -1689,6 +1690,8 @@ Optional Features: --enable-version-specific-runtime-libs Specify that runtime libraries should be installed in a compiler-specific directory + --disable-compat-libstdcxx-abi-mangling + Disable backward-compatibility mangling ABI symbols Optional Packages: --with-PACKAGE[=ARG] use PACKAGE [ARG=yes] @@ -12280,7 +12283,7 @@ else lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2 lt_status=$lt_dlunknown cat > conftest.$ac_ext <<_LT_EOF -#line 12283 "configure" +#line 12286 "configure" #include "confdefs.h" #if HAVE_DLFCN_H @@ -12386,7 +12389,7 @@ else lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2 lt_status=$lt_dlunknown cat > conftest.$ac_ext <<_LT_EOF -#line 12389 "configure" +#line 12392 "configure" #include "confdefs.h" #if HAVE_DLFCN_H @@ -16182,7 +16185,7 @@ $as_echo "$glibcxx_cv_atomic_long_long" >&6; } # Fake what AC_TRY_COMPILE does. cat > conftest.$ac_ext << EOF -#line 16185 "configure" +#line 16188 "configure" int main() { typedef bool atomic_type; @@ -16217,7 +16220,7 @@ $as_echo "$glibcxx_cv_atomic_bool" >&6; } rm -f conftest* cat > conftest.$ac_ext << EOF -#line 16220 "configure" +#line 16223 "configure" int main() { typedef short atomic_type; @@ -16252,7 +16255,7 @@ $as_echo "$glibcxx_cv_atomic_short" >&6; } rm -f conftest* cat > conftest.$ac_ext << EOF -#line 16255 "configure" +#line 16258 "configure" int main() { // NB: _Atomic_word not necessarily int. @@ -16288,7 +16291,7 @@ $as_echo "$glibcxx_cv_atomic_int" >&6; } rm -f conftest* cat > conftest.$ac_ext << EOF -#line 16291 "configure" +#line 16294 "configure" int main() { typedef long long atomic_type; @@ -16444,7 +16447,7 @@ $as_echo "mutex" >&6; } # unnecessary for this test. cat > conftest.$ac_ext << EOF -#line 16447 "configure" +#line 16450 "configure" int main() { _Decimal32 d1; @@ -16486,7 +16489,7 @@ ac_compiler_gnu=$ac_cv_cxx_compiler_gnu # unnecessary for this test. cat > conftest.$ac_ext << EOF -#line 16489 "configure" +#line 16492 "configure" template struct same { typedef T2 type; }; @@ -55671,7 +55674,35 @@ $as_echo "$gxx_include_dir" >&6; } # OPTIMIZE_CXXFLAGS = -O3 -fstrict-aliasing -fvtable-gc - WARN_FLAGS="-Wall -Wextra -Wwrite-strings -Wcast-qual -Wabi=2" + WARN_FLAGS="-Wall -Wextra -Wwrite-strings -Wcast-qual" + + + + # Default. + WARN_FLAGS_WABI=\ -Wabi=2 + { $as_echo "$as_me:${as_lineno-$LINENO}: checking for --disable-compat-libstdcxx-abi-mangling" >&5 +$as_echo_n "checking for --disable-compat-libstdcxx-abi-mangling... " >&6; } + # Check whether --enable-compat-libstdcxx-abi-mangling was given. +if test "${enable_compat_libstdcxx_abi_mangling+set}" = set; then : + enableval=$enable_compat_libstdcxx_abi_mangling; case "$enableval" in + yes) { $as_echo "$as_me:${as_lineno-$LINENO}: result: enabled$WARN_FLAGS_WABI" >&5 +$as_echo "enabled$WARN_FLAGS_WABI" >&6; } ;; + no) WARN_FLAGS_WABI= + { $as_echo "$as_me:${as_lineno-$LINENO}: result: disabled" >&5 +$as_echo "disabled" >&6; } ;; + *) { $as_echo "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5 +$as_echo "unsupported" >&6; } + as_fn_error $? "Unsupported argument to enable/disable compat libstdc++ abi mangling" "$LINENO" 5;; + esac +else + + { $as_echo "$as_me:${as_lineno-$LINENO}: result: defaulting to enabled$WARN_FLAGS_WABI" >&5 +$as_echo "defaulting to enabled$WARN_FLAGS_WABI" >&6; } + +fi + + + WARN_FLAGS="$WARN_FLAGS$WARN_FLAGS_WABI" diff --git a/libstdc++-v3/doc/html/manual/configure.html b/libstdc++-v3/doc/html/manual/configure.html index 346b5d345cd..cdbaaabcb2a 100644 --- a/libstdc++-v3/doc/html/manual/configure.html +++ b/libstdc++-v3/doc/html/manual/configure.html @@ -108,6 +108,8 @@ then the [time.clock] implementation will use a system call to access the realtime and monotonic clocks, which is significantly slower than the C library's clock_gettime function. +

--disable-compat-libstdcxx-abi-mangling

Disables + backward-compatibility mangling ABI symbols.

--enable-libstdcxx-debug

Build separate debug libraries in addition to what is normally built. By default, the debug libraries are compiled with CXXFLAGS='-g3 -O0 -fno-inline' @@ -308,4 +310,4 @@ smaller library, so is suitable for systems that will never need to query the time zone database. This does not change the library ABI. -

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diff --git a/libstdc++-v3/doc/xml/manual/configure.xml b/libstdc++-v3/doc/xml/manual/configure.xml index 0a477ab85e5..ab46db490dc 100644 --- a/libstdc++-v3/doc/xml/manual/configure.xml +++ b/libstdc++-v3/doc/xml/manual/configure.xml @@ -189,6 +189,10 @@ + --disable-compat-libstdcxx-abi-mangling + Disables backward-compatibility mangling ABI symbols. + + --enable-libstdcxx-debug Build separate debug libraries in addition to what is normally built. By default, the debug libraries are compiled with