llvm 3.42 build from source fails on ubuntu 17.04

I have a script that builds llvm/clang 3.42 from source (with configure+make). It runs smooth on ubuntu 14.04.5 LTS. When I upgraded to ubuntu 17.04, the build fails.

Here is the building script:

svn co https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_342/final llvm
svn co https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_342/final llvm/tools/clang
svn co https://llvm.org/svn/llvm-project/compiler-rt/tags/RELEASE_342/final llvm/projects/compiler-rt
svn co https://llvm.org/svn/llvm-project/libcxx/tags/RELEASE_342/final llvm/projects/libcxx

rm -rf llvm/.svn
rm -rf llvm/tools/clang/.svn
rm -rf llvm/projects/compiler-rt/.svn
rm -rf llvm/projects/libcxx/.svn

cd llvm
./configure \
--enable-optimized \
--disable-assertions \
--enable-targets=host \
--with-python="/usr/bin/python2"

make -j `nproc`

Here are the errors I get (TLDR: problems with definitions of malloc, calloc, realloc and free)

/usr/include/malloc.h:38:14: error: declaration conflicts with target of using declaration already in scope
extern void *malloc (size_t __size) __THROW __attribute_malloc__ __wur;
             ^
/usr/include/stdlib.h:427:14: note: target of using declaration
extern void *malloc (size_t __size) __THROW __attribute_malloc__ __wur;
             ^
/usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3./stdlib.h:65:12: note: using declaration
using std::malloc;
           ^
In file included from /home/oren/GIT/LatestKlee/llvm/projects/compiler-rt/lib/tsan/rtl/tsan_platform_linux.cc:47:
/usr/include/malloc.h:41:14: error: declaration conflicts with target of using declaration already in
  scope
extern void *calloc (size_t __nmemb, size_t __size)
             ^
/usr/include/stdlib.h:429:14: note: target of using declaration
extern void *calloc (size_t __nmemb, size_t __size)
             ^
/usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/stdlib.h:59:12: note: using declaration
using std::calloc;
           ^
In file included from /home/oren/GIT/LatestKlee/llvm/projects/compiler-rt/lib/tsan/rtl/tsan_platform_linux.cc:47:
/usr/include/malloc.h:49:14: error: declaration conflicts with target of using declaration already in
  scope
extern void *realloc (void *__ptr, size_t __size)
             ^
/usr/include/stdlib.h:441:14: note: target of using declaration
extern void *realloc (void *__ptr, size_t __size)
             ^
/usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/stdlib.h:73:12: note: using declaration
using std::realloc;
           ^
In file included from /home/oren/GIT/LatestKlee/llvm/projects/compiler-rt/lib/tsan/rtl/tsan_platform_linux.cc:47:
/usr/include/malloc.h:53:13: error: declaration conflicts with target of using declaration already in
  scope
extern void free (void *__ptr) __THROW;
            ^
/usr/include/stdlib.h:444:13: note: target of using declaration
extern void free (void *__ptr) __THROW;
            ^
/usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/stdlib.h:61:12: note: using declaration
using std::free;
           ^
COMPILE:   clang_linux/tsan-x86_64/x86_64: /home/oren/GIT/LatestKlee/llvm/projects/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cc
4 errors generated.
Makefile:267: recipe for target '/home/oren/GIT/LatestKlee/llvm/tools/clang/runtime/compiler-rt/clang_linux/tsan-x86_64/x86_64/SubDir.lib__tsan__rtl/tsan_platform_linux.o' failed
make[5]: *** [/home/oren/GIT/LatestKlee/llvm/tools/clang/runtime/compiler-rt/clang_linux/tsan-x86_64/x86_64/SubDir.lib__tsan__rtl/tsan_platform_linux.o] Error 1

The default gcc version shipped with ubuntu 17.04 is 6.3. Maybe this is an issue of default C++ dialect used by gcc 6.3? Any help is very much appreciated, thanks!

回答1:

That seems to be an issue with LLVM 3.4.2tsan (Thread Sanitizer) failing to build with GCC 6.x, as previously reported here:

https://aur.archlinux.org/packages/clang34-analyzer-split

It seems the inclusion of stdlib.h and malloc.h is conflicting, since both define malloc and friends.

It's possible that this issue only manifets in tsan, so if tsan is not instrumental to your LLVM build (which is very likely), and you wish to stick with the system gcc for building LLVM, you may consider disabling tsan completely.

If you're running a CMake build (as in here), you can do so by commenting line 29 of llvm/projects/compiler-rt/lib/CMakeLists.txt:

if (CMAKE_SYSTEM_NAME MATCHES "Linux" AND NOT ANDROID)  
  add_subdirectory(tsan) # comment out this line

If you're forced to stick to the configure build, my best guess would be removing the tsan-x86_64 target in llvm/projects/compiler-rt/make/clang_linux.mk, line 63:

Configs += full-x86_64 profile-x86_64 san-x86_64 asan-x86_64 --> tsan-x86_64 <--

回答2:

I faced the same problem on my Ubuntu 16.10. It has default gcc 6.2. You need to instruct LLVM build system to use gcc 4.9. Also, I suggest you remove GCC6 completely.

$ sudo apt-get remove g++-6 gcc-6 cpp
$ sudo apt-get install gcc-4.9 g++4.9
$ export CC=/usr/bin/gcc-4.9
$ export CXX=/usr/bin/g++-4.9
$ export CPP=/usr/bin/cpp-4.9
$ ./configure
$ make

And maybe you will need:

$ sudo ln -s /usr/bin/cpp-4.9 /usr/bin/cpp