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

Chandler Carruth chandlerc at gmail.com
Wed Jan 15 13:49:16 PST 2014


Looks like this did the trick on the upstream bots:
http://lab.llvm.org:8013/builders/clang-x86_64-darwin11-nobootstrap-RAincremental/builds/11183

Lemme know if you're still seeing trouble.


On Wed, Jan 15, 2014 at 1:27 PM, Chandler Carruth <chandlerc at gmail.com>wrote:

> Ok, r199334! =]
>
> But thanks so much for replicating the problematic config on the bots, now
> I'll be able to watch them closely and immediately iterate on this.
>
>
> On Wed, Jan 15, 2014 at 1:20 PM, Chandler Carruth <chandlerc at gmail.com>wrote:
>
>> 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
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>>>> >>>>
>>>> >>>>
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>>>> >>>>
>>>> >>>
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