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I have posted my failures of building llvm 3.42 with gcc6.3 here and here. I am posting separately the failure of clang 4.0 to build llvm 3.42 from source as these are somewhat different developers communities. Here is the script I've used:

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 CC=clang CXX=clang++ ./configure \ --enable-optimized \ --disable-assertions \ --enable-targets=host \ --with-python="/usr/bin/python2" make -j `nproc`

And here is the error I got:

[ 17%] Linking CXX executable ../../bin/yaml-bench ../../lib/libLLVMSupport.a(Allocator.cpp.o): In function `llvm::BumpPtrAllocator::Allocate(unsigned long, unsigned long)': /home/oren/GIT/myLLVMpass/llvm-3.4.2/llvm/lib/Support/Allocator.cpp:(.text+0x377): undefined reference to `__msan_allocated_memory' /home/oren/GIT/myLLVMpass/llvm-3.4.2/llvm/lib/Support/Allocator.cpp:(.text+0x40b): undefined reference to `__msan_allocated_memory' /home/oren/GIT/myLLVMpass/llvm-3.4.2/llvm/lib/Support/Allocator.cpp:(.text+0x453): undefined reference to `__msan_allocated_memory' clang: error: linker command failed with exit code 1 (use -v to see invocation) utils/not/CMakeFiles/not.dir/build.make:95: recipe for target 'bin/not' failed

EDIT: (after adding @valiano's suggestion) There are still errors, here is the terminal output:

In file included from /home/oren/GIT/LatestKlee/llvm/projects/compiler-rt/lib/tsan/rtl/tsan_platform_linux.cc:47: /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++/6.3.0/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 ASSEMBLE: clang_linux/tsan-x86_64/x86_64: /home/oren/GIT/LatestKlee/llvm/projects/compiler-rt/lib/tsan/rtl/tsan_rtl_amd64.S 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; ^ 4 errors generated.

Is there any way out of this? thanks in advance!

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  • That's tough. I have an advice, though. The LLVM autotools build is long deprecated and have been so since 3.9 (see releases.llvm.org/3.8.0/docs/BuildingLLVMWithAutotools.html). I think you have better chances of properly customizing/fixing the build, and also better chance of getting help, if you'll use the CMake build (I realize that's were you started from). The autotools LLVM build is not sustainable anyway, and you'll need to migrate your build to CMake if you choose (or the host project chooses) to update the LLVM version at some point. Commented Jan 11, 2018 at 6:19

1 Answer 1

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That seems to be an issue with LLVM 3.4.2 source code and memory sanitizer headers.

In short, you'll need to patch two source files, lib/Support/Allocator.cpp and lib/Target/X86/X86JITInfo.cpp, for removing usages of the functions__msan_allocated_memory and __msan_unpoison:

sed -i 's/__msan_unpoison/\/\/__msan_unpoison/' ./llvm/lib/Target/X86/X86JITInfo.cpp sed -i 's/__msan_allocated_memory/\/\/__msan_allocated_memory/' llvm/lib/Support/Allocator.cpp

These function calls are only there for LLVM builds with memory sanitizer instrumentation, and otherwise not needed.

With this patch, you should be able to build LLVM/clang 3.4.2 with clang 4.0 with no further issues.

Reason this happens:

These functions are of the memory sanitizer and they're called from LLVM code assuming that LLVM is built with memory sanitizer instrumentation (-fsanitize=memory), and otherwise, they are disabled (ifdef'd out).

The relevant header code is in include/llvm/Support/Compiler.h:

/// \macro LLVM_MEMORY_SANITIZER_BUILD /// \brief Whether LLVM itself is built with MemorySanitizer instrumentation. #if __has_feature(memory_sanitizer) # define LLVM_MEMORY_SANITIZER_BUILD 1 # include <sanitizer/msan_interface.h> #else # define LLVM_MEMORY_SANITIZER_BUILD 0 # define __msan_allocated_memory(p, size) # define __msan_unpoison(p, size) #endif

From some reason, the first if clause is chosen, instead of the second one, even though the build is made without memory sanitizer enabled (perhaps the toggling of __has_feature(memory_sanitizer) macro is broken).

See here additional reports regarding this issue.

Edit:

For solving the following issue of tsan failing to build due to malloc redeclarations, you may consider omitting tsan from your LLVM build, as described here.

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2 Comments

there are still compilation errors, regarding malloc, calloc, realloc and free ... any other ideas? thanks!
@OrenIshShalom this is probably a different issue, maybe related to GCC 6.3 headers. I guess it's the same as stackoverflow.com/questions/48146921/…? Anyway I'll try to reproduce it with my local setup.

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