[LLVMdev] r204593 breaks Asan tests on FreeBSD

[Ivan A. Kosarev]

Hello Alexey,

I just worked out the config for the FreeBSD 9.2 buildbot (follows 
below). One important thing about this config is that the C++11 headers 
are set up at the /usr/include/c++/v1 directory--it's where clang 
expects them to be on FreeBSD, so no need for the "-I" options in the 
CMAKE_CXX_FLAGS variable. Unfortunately, clang (both v3.3 used to be the 
default compiler on FreeBSD 9.2 and recent revisions) do not add the 
libcxxrt run-time lib to ld options what means we have to ask cmake to 
add it for us (see the cmake invocation at the end of the config list). 
This approach let us build and run the common sanitizers tests with no 
unexpected failures. The only issue is that the HAVE_UNIT64_T & Co. 
tests fail to link due to omitted reference to libcxxrt. The quick fix 
is trivial:

---
Index: cmake/config-ix.cmake
===================================================================
--- cmake/config-ix.cmake    (revision 205543)
+++ cmake/config-ix.cmake    (working copy)
@@ -17,6 +17,7 @@
    # Used by check_symbol_exists:
    set(CMAKE_REQUIRED_LIBRARIES m)
  endif()
+list(APPEND CMAKE_REQUIRED_LIBRARIES ${LLVM_CONFIG_TEST_LIBRARIES})

  # Helper macros and functions
  macro(add_cxx_include result files)
---

Do you think this fix would make sense for building llvm on other 
platforms? I mean, do you think it looks acceptable to be sent for 
review and commit? Please let me know.

Also, I believe I should prepare a patch that adds the -lcxxrt option 
for a linker on FreeBSD so one day we can build llvm on FreeBSD without 
all these tricky things.

The config is this:
---
# The proposed buildbot config for FreeBSD 9.2

# we have to install these from ports as the packages versions are too old
cd /usr/ports/devel/subversion
sudo make BATCH=1 install clean

cd /usr/ports/devel/libc++
sudo make BATCH=1
sudo make PREFIX=/usr install clean

cd /usr/src/lib/libcxxrt
sudo make
sudo make install clean

cd /usr/ports/shells/bash
sudo make BATCH=1 install clean

cd /usr/ports/textproc/gnugrep
sudo make BATCH=1 install clean

wget -c ftp://ftp.gnu.org/gnu/binutils/binutils-2.24.tar.gz
./configure --prefix=/usr --enable-language=c,c++
gmake
sudo gmake install

# these are necessary to pass LLVM :: BugPoint/compile-custom.ll
sudo pkg install gcc
sudo pkg install python

CC=clang CXX=clang++ cmake \
     -DCMAKE_CXX_FLAGS="-std=c++11 -stdlib=libc++" \
     -DCMAKE_CXX_COMPILER_WORKS=1 \
     -DCMAKE_EXE_LINKER_FLAGS="-lcxxrt" \
     -DLLVM_CONFIG_TEST_LIBRARIES="cxxrt" \
     ../llvm
---

Thanks!

--