[LLVMdev] CMake build maturity

Paul Melis llvm at assumetheposition.nl
Mon Jun 1 04:44:29 PDT 2009

Paul Melis wrote:
> Óscar Fuentes wrote:
>> Paul Melis <llvm at assumetheposition.nl> writes:
>>> It seems that the llvm-config generated when building through CMake does
>>> not contain -lpthread on my 32-bit Core2Duo Gentoo Linux system (even
>>> though I configured with LLVM_ENABLE_PTHREADS). I get missing symbols
>>> during linking of e.g. the JIT tutorial code:
>> [snip]
>> This should be fixed now. Now about this one:
>>> Adding -lpthread to the compile command manually fixes it, but there
>>> seem to be some more discrepancies between the output of llvm-config for
>>> a build using ./configure and one using CMake:
>>> melis at juggle2:~/c/llvm-svn> ./configure --prefix=/home/melis/llvm
>>> --enable-optimized
>>> melis at juggle2:~/c/llvm-svn> make install
>>> melis at juggle2:~/c/llvm-svn> which llvm-config
>>> /home/melis/llvm/bin/llvm-config
>>> melis at juggle2:~/c/llvm-svn> llvm-config --cxxflags --ldflags --libs core
>>> -I/home/melis/llvm/include  -D_DEBUG  -D_GNU_SOURCE
>>> -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS -O3 -fomit-frame-pointer
>>> -fPIC  -Woverloaded-virtual
>>> -L/home/melis/llvm/lib  -lpthread -ldl -lm -lelf
>>> -lLLVMCore -lLLVMSupport -lLLVMSystem
>>> melis at juggle2:~/c/llvm-svn-build> cmake /home/melis/c/llvm-svn
>>> -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/home/melis/llvm-cmake
>>> melis at juggle2:~/c/llvm-svn-build> make install
>>> melis at juggle2:~/c/llvm-svn-build> which llvm-config
>>> /home/melis/llvm-cmake/bin/llvm-config
>>> melis at juggle2:~/c/llvm-svn-build> llvm-config --cxxflags --ldflags
>>> --libs core
>>> -I/home/melis/llvm-cmake/include -O3 -DNDEBUG  -D_GNU_SOURCE
>>> -L/home/melis/llvm-cmake/lib 
>>> -lLLVMCore -lLLVMSupport -lLLVMSystem
>>> I'm actually also surprised about the _DEBUG versus NDEBUG difference...
>> I'm surprised too.
>> Question for those who know: why is _DEBUG and not NDEBUG defined on a
>> --enable-optimize'd build?
> I guess to keep all the assertions around. I think you need
> --disable-assertions to make those go away as well.
Just checked: yup, there's plenty of assert()'s in the headers, so
-D_DEBUG will keep those alive.

Interestingly, when configuring with --enable-optimized and
--disable-assertions the resulting compilation calls itself a
"Release-Asserts build" while all asserts are thrown away, hmmm :)


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