[llvm] r199313 - Add a check to configure that the libstdc++ selected by Clang isn't

Chandler Carruth chandlerc at gmail.com
Wed Jan 15 13:20:08 PST 2014


Ahh, I see why... the --enable-libcpp thing doesn't work at all the way
autoconf tests usually work, in part because it is relying on the very
strange LLVM makefile arrangement...

I'll try a totally different approach, give me a bit.


On Wed, Jan 15, 2014 at 1:18 PM, Chandler Carruth <chandlerc at gmail.com>wrote:

> That configure log doesn't appear to have my change... investigating
> further...
>
>
> On Wed, Jan 15, 2014 at 12:50 PM, Duncan P. N. Exon Smith <
> dexonsmith at apple.com> wrote:
>
>> Hi Chandler,
>>
>> I finally found the spot to update zorg and reconfigured it.  I reran
>> r199325 with --enable-libcpp here:
>>
>>
>> http://lab.llvm.org:8013/builders/clang-x86_64-darwin11-nobootstrap-RAincremental/builds/11180
>>
>> Here’s a link to the call to configure:
>>
>>
>> http://lab.llvm.org:8013/builders/clang-x86_64-darwin11-nobootstrap-RAincremental/builds/11180/steps/configure.with.host/logs/stdio
>>
>> Duncan
>>
>> On Jan 15, 2014, at 12:29 PM, Bob Wilson <bob.wilson at apple.com> wrote:
>>
>> > Nope.  Still not working.
>> >
>> > Duncan is going to change the lab.llvm.org bot to use —enable-libcpp
>> so you can see the status for yourself.
>> >
>> http://lab.llvm.org:8013/builders/clang-x86_64-darwin11-nobootstrap-RAincremental
>> >
>> > On Jan 15, 2014, at 11:24 AM, Chandler Carruth <chandlerc at gmail.com>
>> wrote:
>> >
>> >> Hopefully r199325 fixes this. It's not really pretty, but I wanted to
>> get you something before spending more time looking for the "right" place
>> to do this test.
>> >>
>> >>
>> >> On Wed, Jan 15, 2014 at 10:26 AM, Bob Wilson <bob.wilson at apple.com>
>> wrote:
>> >>
>> >> On Jan 15, 2014, at 10:25 AM, Chandler Carruth <chandlerc at gmail.com>
>> wrote:
>> >>
>> >>> On Wed, Jan 15, 2014 at 10:20 AM, Bob Wilson <bob.wilson at apple.com>
>> wrote:
>> >>> Our buildbots have an old version of libstdc++ that has that problem.
>>  But, we run configure with -stdlib=libc++, so it doesn’t matter what
>> version of libstdc++ is on the machine.
>> >>>
>> >>> The configure check is not honoring —enable-libcpp, so it’s checking
>> the wrong library.
>> >>>
>> >>> Ahh, I see, it's because the enabling of libc++ happens too late. I
>> had expected that when the host was clang on darwin it would *default* to
>> libc++, sorry for that.
>> >>
>> >> It does default to libc++ on Mavericks but most of our buildbots are
>> still running Mountain Lion.
>> >>
>> >>>
>> >>> Lemme try re-shuffling these tests to better cope with that.
>> >>
>> >> Thanks!
>> >>
>> >>>
>> >>>
>> >>>
>> >>> On Jan 15, 2014, at 10:17 AM, Chandler Carruth <chandlerc at gmail.com>
>> wrote:
>> >>>
>> >>>> On Wed, Jan 15, 2014 at 10:13 AM, Bob Wilson <bob.wilson at apple.com>
>> wrote:
>> >>>> We shouldn’t be checking this when configure is run with
>> —enable-libcpp.  This is breaking all of our buildbots.
>> >>>>
>> >>>> Why?
>> >>>>
>> >>>> Notably, is there some version of libc++ which *also* has the bug
>> that libstdc++ has?
>> >>>>
>> >>>>
>> >>>> On Jan 15, 2014, at 2:31 AM, 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
>> >>>>
>> >>>
>> >>>
>> >>> _______________________________________________
>> >>> 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
>> >>
>> >>
>> >
>>
>>
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20140115/e68ddd80/attachment.html>


More information about the llvm-commits mailing list