[llvm] r199313 - Add a check to configure that the libstdc++ selected by Clang isn't
Stepan Dyatkovskiy
stpworld at narod.ru
Mon Jan 20 01:04:59 PST 2014
Hi guys,
Now it passed configure stage on FreeBSD-9.2 machine,
but it failed on test-suite with a lot of messages like that:
Output/city.llvm.bc:(.text+0x1af): undefined reference to `std::__1::basic_ostream<char, std::__1::char_traits<char> >::sentry::sentry(std::__1::basic_ostream<char, std::__1::char_traits<char> >&)'
I suppose the trouble is still related to r199313.
Perhaps we could install gcc-4.7, it also will bring new libstdc++? Though now I suppose it ignores this this lib at all, and doesn't link any replacement for that.
-Stepan.
17.01.2014, 12:20, "Evgeniy Stepanov" <eugeni.stepanov at gmail.com>:
> Do you plan to add the same check to cmake?
>
> On Wed, Jan 15, 2014 at 2:31 PM, Chandler Carruth <chandlerc at gmail.com> wrote:
>
>> Author: chandlerc
>> Date: Wed Jan 15 04:31:15 2014
>> New Revision: 199313
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=199313&view=rev
>> Log:
>> Add a check to configure that the libstdc++ selected by Clang isn't
>> libstdc++v4.6. This is quite hard to test directly, so we test for it by
>> checking a known missing feature in that version that was added in v4.7.
>>
>> This should prevent users from upgrading Clang but not GCC and hosting
>> with a too-old GCC's libstdc++ and getting strange and hard to debug
>> errors when we switch to C++11 by default.
>>
>> Also, switch several of the macros I introduced to use AC_LANG_SOURCE
>> rather than AC_LANG_PROGRAM as we don't need configure's help writing
>> our main function (and we don't need such a function at all for most of
>> the tests).
>>
>> Modified:
>> llvm/trunk/autoconf/configure.ac
>> llvm/trunk/configure
>>
>> Modified: llvm/trunk/autoconf/configure.ac
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/autoconf/configure.ac?rev=199313&r1=199312&r2=199313&view=diff
>> ==============================================================================
>> --- llvm/trunk/autoconf/configure.ac (original)
>> +++ llvm/trunk/autoconf/configure.ac Wed Jan 15 04:31:15 2014
>> @@ -102,15 +102,15 @@ dnl other possible compilers.
>> AC_MSG_CHECKING([whether GCC or Clang is our host compiler])
>> AC_LANG_PUSH([C++])
>> llvm_cv_cxx_compiler=unknown
>> -AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#if ! __clang__
>> - #error
>> - #endif
>> - ]])],
>> +AC_COMPILE_IFELSE([AC_LANG_SOURCE([[#if ! __clang__
>> + #error
>> + #endif
>> + ]])],
>> llvm_cv_cxx_compiler=clang,
>> - [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#if ! __GNUC__
>> - #error
>> - #endif
>> - ]])],
>> + [AC_COMPILE_IFELSE([AC_LANG_SOURCE([[#if ! __GNUC__
>> + #error
>> + #endif
>> + ]])],
>> llvm_cv_cxx_compiler=gcc, [])])
>> AC_LANG_POP([C++])
>> AC_MSG_RESULT([${llvm_cv_cxx_compiler}])
>> @@ -129,7 +129,7 @@ case "$enableval" in
>> case "$llvm_cv_cxx_compiler" in
>> clang)
>> AC_MSG_CHECKING([whether Clang is new enough])
>> - AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
>> + AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
>> #if __clang_major__ < 3 || (__clang_major__ == 3 && __clang_minor__ < 1)
>> #error This version of Clang is too old to build LLVM
>> #endif
>> @@ -140,10 +140,34 @@ case "$enableval" in
>> The selected Clang compiler is not new enough to build LLVM. Please upgrade to
>> Clang 3.1. You may pass --disable-compiler-version-checks to configure to
>> bypass these sanity checks.])])
>> +
>> + dnl Note that libstdc++4.6 is known broken for C++11 builds. The errors
>> + dnl are sometimes deeply confusing though. Here we test for an obvious
>> + dnl incomplete feature in 4.6's standard library that was completed in
>> + dnl 4.7's.
>> + AC_MSG_CHECKING([whether Clang will select a modern C++ standard library])
>> + llvm_cv_old_cxxflags="$CXXFLAGS"
>> + CXXFLAGS="$CXXFLAGS -std=c++0x"
>> + AC_LINK_IFELSE([AC_LANG_SOURCE([[
>> +#include <atomic>
>> +std::atomic<float> x(0.0f);
>> +int main() { return (float)x; }
>> +]])],
>> + [AC_MSG_RESULT([yes])],
>> + [AC_MSG_RESULT([no])
>> + AC_MSG_ERROR([
>> +We detected a missing feature in the standard C++ library that was known to be
>> +missing in libstdc++4.6 and implemented in libstdc++4.7. There are numerous
>> +C++11 problems with 4.6's library, and we don't support GCCs or libstdc++ older
>> +than 4.7. You will need to update your system and ensure Clang uses the newer
>> +standard library.
>> +
>> +If this error is incorrect or you need to force things to work, you may pass
>> +'--disable-compiler-version-checks' to configure to bypass this test.])])
>> ;;
>> gcc)
>> AC_MSG_CHECKING([whether GCC is new enough])
>> - AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
>> + AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
>> #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
>> #error This version of GCC is too old to build LLVM
>> #endif
>>
>> Modified: llvm/trunk/configure
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/configure?rev=199313&r1=199312&r2=199313&view=diff
>> ==============================================================================
>> --- llvm/trunk/configure (original)
>> +++ llvm/trunk/configure Wed Jan 15 04:31:15 2014
>> @@ -3593,16 +3593,9 @@ cat confdefs.h >>conftest.$ac_ext
>> cat >>conftest.$ac_ext <<_ACEOF
>> /* end confdefs.h. */
>> #if ! __clang__
>> - #error
>> - #endif
>> + #error
>> + #endif
>>
>> -int
>> -main ()
>> -{
>> -
>> - ;
>> - return 0;
>> -}
>> _ACEOF
>> rm -f conftest.$ac_objext
>> if { (ac_try="$ac_compile"
>> @@ -3650,16 +3643,9 @@ cat confdefs.h >>conftest.$ac_ext
>> cat >>conftest.$ac_ext <<_ACEOF
>> /* end confdefs.h. */
>> #if ! __GNUC__
>> - #error
>> - #endif
>> -
>> -int
>> -main ()
>> -{
>> + #error
>> + #endif
>>
>> - ;
>> - return 0;
>> -}
>> _ACEOF
>> rm -f conftest.$ac_objext
>> if { (ac_try="$ac_compile"
>> @@ -3748,13 +3734,6 @@ cat >>conftest.$ac_ext <<_ACEOF
>> #error This version of Clang is too old to build LLVM
>> #endif
>>
>> -int
>> -main ()
>> -{
>> -
>> - ;
>> - return 0;
>> -}
>> _ACEOF
>> rm -f conftest.$ac_objext
>> if { (ac_try="$ac_compile"
>> @@ -3810,6 +3789,88 @@ bypass these sanity checks." >&2;}
>> fi
>>
>> rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
>> +
>> + { echo "$as_me:$LINENO: checking whether Clang will select a modern C++ standard library" >&5
>> +echo $ECHO_N "checking whether Clang will select a modern C++ standard library... $ECHO_C" >&6; }
>> + llvm_cv_old_cxxflags="$CXXFLAGS"
>> + CXXFLAGS="$CXXFLAGS -std=c++0x"
>> + cat >conftest.$ac_ext <<_ACEOF
>> +/* confdefs.h. */
>> +_ACEOF
>> +cat confdefs.h >>conftest.$ac_ext
>> +cat >>conftest.$ac_ext <<_ACEOF
>> +/* end confdefs.h. */
>> +
>> +#include <atomic>
>> +std::atomic<float> x(0.0f);
>> +int main() { return (float)x; }
>> +
>> +_ACEOF
>> +rm -f conftest.$ac_objext conftest$ac_exeext
>> +if { (ac_try="$ac_link"
>> +case "(($ac_try" in
>> + *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
>> + *) ac_try_echo=$ac_try;;
>> +esac
>> +eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
>> + (eval "$ac_link") 2>conftest.er1
>> + ac_status=$?
>> + grep -v '^ *+' conftest.er1 >conftest.err
>> + rm -f conftest.er1
>> + cat conftest.err >&5
>> + echo "$as_me:$LINENO: \$? = $ac_status" >&5
>> + (exit $ac_status); } &&
>> + { ac_try='test -z "$ac_cxx_werror_flag" || test ! -s conftest.err'
>> + { (case "(($ac_try" in
>> + *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
>> + *) ac_try_echo=$ac_try;;
>> +esac
>> +eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
>> + (eval "$ac_try") 2>&5
>> + ac_status=$?
>> + echo "$as_me:$LINENO: \$? = $ac_status" >&5
>> + (exit $ac_status); }; } &&
>> + { ac_try='test -s conftest$ac_exeext'
>> + { (case "(($ac_try" in
>> + *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
>> + *) ac_try_echo=$ac_try;;
>> +esac
>> +eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
>> + (eval "$ac_try") 2>&5
>> + ac_status=$?
>> + echo "$as_me:$LINENO: \$? = $ac_status" >&5
>> + (exit $ac_status); }; }; then
>> + { echo "$as_me:$LINENO: result: yes" >&5
>> +echo "${ECHO_T}yes" >&6; }
>> +else
>> + echo "$as_me: failed program was:" >&5
>> +sed 's/^/| /' conftest.$ac_ext >&5
>> +
>> + { echo "$as_me:$LINENO: result: no" >&5
>> +echo "${ECHO_T}no" >&6; }
>> + { { echo "$as_me:$LINENO: error:
>> +We detected a missing feature in the standard C++ library that was known to be
>> +missing in libstdc++4.6 and implemented in libstdc++4.7. There are numerous
>> +C++11 problems with 4.6's library, and we don't support GCCs or libstdc++ older
>> +than 4.7. You will need to update your system and ensure Clang uses the newer
>> +standard library.
>> +
>> +If this error is incorrect or you need to force things to work, you may pass
>> +'--disable-compiler-version-checks' to configure to bypass this test." >&5
>> +echo "$as_me: error:
>> +We detected a missing feature in the standard C++ library that was known to be
>> +missing in libstdc++4.6 and implemented in libstdc++4.7. There are numerous
>> +C++11 problems with 4.6's library, and we don't support GCCs or libstdc++ older
>> +than 4.7. You will need to update your system and ensure Clang uses the newer
>> +standard library.
>> +
>> +If this error is incorrect or you need to force things to work, you may pass
>> +'--disable-compiler-version-checks' to configure to bypass this test." >&2;}
>> + { (exit 1); exit 1; }; }
>> +fi
>> +
>> +rm -f core conftest.err conftest.$ac_objext \
>> + conftest$ac_exeext conftest.$ac_ext
>> ;;
>> gcc)
>> { echo "$as_me:$LINENO: checking whether GCC is new enough" >&5
>> @@ -3825,13 +3886,6 @@ cat >>conftest.$ac_ext <<_ACEOF
>> #error This version of GCC is too old to build LLVM
>> #endif
>>
>> -int
>> -main ()
>> -{
>> -
>> - ;
>> - return 0;
>> -}
>> _ACEOF
>> rm -f conftest.$ac_objext
>> if { (ac_try="$ac_compile"
>> @@ -10606,7 +10660,7 @@ else
>> lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
>> lt_status=$lt_dlunknown
>> cat > conftest.$ac_ext <<EOF
>> -#line 10609 "configure"
>> +#line 10663 "configure"
>> #include "confdefs.h"
>>
>> #if HAVE_DLFCN_H
>>
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
More information about the llvm-commits
mailing list