Configure an autotools project with Clang sanitizers in a static lib configuration?

Question

EDIT: If its TLDR, just skip to the bottom. Its where I ask: How do I configure an autotools project to use a static library?

I'm working with a couple of open source libraries, and I'm trying to run their test suite under Clang's sanitizers. To run under Clang sanitizers, we need to (1) specify some options, and (2) link static libraries from Clang's Compiler-RT as required. Note: there are no dynamic libraries or shared objects.

Setting the options is easy:

export DYLD_FALLBACK_LIBRARY_PATH=/usr/local/lib/clang/3.3/lib/darwin/
export CC=/usr/local/bin/clang
export CXX=/usr/local/bin/clang++
export CFLAGS="-g3 -fsanitize=address -fsanitize=undefined"
export CXXFLAGS="-g3 -fsanitize=address -fsanitize=undefined -fno-sanitize=vptr"

./configure

However, this will generate some archive warnings (when AR is run) and link errors (when LD is run) with undefined symbols. The message will be similar to:

libjpeg.a(jmemmgr.o): In function `do_sarray_io':
/home/jwalton/jpeg-6b/jmemmgr.c:695: undefined reference to
`__ubsan_handle_type_mismatch'
/home/jwalton/jpeg-6b/jmemmgr.c:695: undefined reference to
`__ubsan_handle_type_mismatch'
/home/jwalton/jpeg-6b/jmemmgr.c:696: undefined reference to
`__ubsan_handle_type_mismatch'

I know the libraries that need to be linked. For the sanitizers that I use, they are libclang_rt.asan_osx.a and libclang_rt.ubsan_osx.a (or libclang_rt.full-x86_64.a and libclang_rt.ubsan-x86_64.a on Linux).

To supply the libraries, I then export the following. Note: it is LIBS, and not LDLIBS as expected by most other make related tools.

export LIBS="/usr/local/lib/clang/3.3/lib/darwin/libclang_rt.asan_osx.a \
             /usr/local/lib/clang/3.3/lib/darwin/libclang_rt.ubsan_osx.a"

This results in a configure problem of:

configure: error: cannot run C compiled programs.
If you meant to cross compile, use `--host'.
...

Looking at config.log, it looks like two problems are occurring. First, the path is being butchered by changing from /usr/local/... to /Users/jwalton/.... And second, the filename is being butchered by changing from a static lib to a dynamic lib:

configure:3346: ./conftest
dyld: Library not loaded: /Users/jwalton/clang-llvm/llvm-3.3.src/Release+Asserts/lib/clang/3.3/lib/darwin/libclang_rt.asan_osx_dynamic.dylib
  Referenced from: /Users/jwalton/libpng-1.6.7/./conftest
Reason: image not found

In another attempt, I tried using LDFLAGS:

export LDFLAGS="-L/usr/local/lib/clang/3.3/lib/darwin/"
export LIBS="libclang_rt.asan_osx.a libclang_rt.ubsan_osx.a"

That results in a similar error:

configure: error: in `/Users/jwalton/libpng-1.6.7':
configure: error: C compiler cannot create executables

And config.log:

configure:3209: /usr/local/bin/clang -g3 -fsanitize=address -fsanitize=undefined  -L/usr/local/lib/clang/3.3/lib/darwin/ conftest.c libclang_rt.asan_osx.a libclang_rt.ubsan_osx.a >&5
clang: error: no such file or directory: 'libclang_rt.asan_osx.a'
clang: error: no such file or directory: 'libclang_rt.ubsan_osx.a'

And dropping the lib prefix and .a suffix from the LIBS results in:

configure:3209: /usr/local/bin/clang -g3 -fsanitize=address -fsanitize=undefined  -L/usr/local/lib/clang/3.3/lib/darwin/ conftest.c clang_rt.asan_osx clang_rt.ubsan_osx >&5
clang: error: no such file or directory: 'clang_rt.asan_osx'
clang: error: no such file or directory: 'clang_rt.ubsan_osx'

And adding the -l to LIBS results in:

configure:3335: /usr/local/bin/clang -o conftest -g3 -fsanitize=address -fsanitize=undefined  
    -L/usr/local/lib/clang/3.3/lib/darwin/ conftest.c -lclang_rt.asan_osx -lclang_rt.ubsan_osx >&5
configure:3339: $? = 0
configure:3346: ./conftest
dyld: could not load inserted library: /Users/jwalton/libpng-1.6.7/./conftest

./configure: line 3348: 38224 Trace/BPT trap: 5       ./conftest$ac_cv_exeext

Finally, the -L argument is valid:

$ ls /usr/local/lib/clang/3.3/lib/darwin/
libclang_rt.10.4.a          libclang_rt.ios.a
libclang_rt.asan_osx.a          libclang_rt.osx.a
libclang_rt.asan_osx_dynamic.dylib  libclang_rt.profile_ios.a
libclang_rt.cc_kext.a           libclang_rt.profile_osx.a
libclang_rt.cc_kext_ios5.a      libclang_rt.ubsan_osx.a
libclang_rt.eprintf.a

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After all the background: how do I configure an autotools project to use a static library?

Bonus points: why has something so easy been made so difficult?

Answer 1

You need to add -fsanitize flags to LDFLAGS as well.