[LLVMdev] Building LLVM with asan

[Alexander Potapenko]

Yeah, it's not linking the runtime because you're building a shared
library. This is totally ok. In this case there are undefined __asan_*
symbols that are resolved when an instrumented binary loads your library.
What's wrong here is that some flag passed to ld prevents it from creating
undefined symbols (--no-undefined?). This flag must be removed when
building with ASan.
This isn't the case on OSX where the runtime is a dynamic library and can
safely be linked to instrumented dynamic libraries.
What I meant to say was that it worked for me on OS X on a slightly older
version of LLVM. Anyway, here's the ld line:

 "/usr/bin/ld" -export-dynamic -z relro --hash-style=gnu --build-id
--eh-frame-hdr -m elf_x86_64 -shared -o
/home/kfischer/julia/deps/llvm-svn/build_Release+Asserts+Sanitize/Release+Asserts/lib/
libLLVM-3.5svn.so/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crti.o
/usr/lib/gcc/x86_64-linux-gnu/4.8/crtbeginS.o
-L/home/kfischer/julia/deps/llvm-svn/build_Release+Asserts+Sanitize/Release+Asserts/lib
-L/home/kfischer/julia/deps/llvm-svn/build_Release+Asserts+Sanitize/Release+Asserts/lib
-L/usr/lib/gcc/x86_64-linux-gnu/4.8
-L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu
-L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu
-L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../.. -L/lib -L/usr/lib -R
"\$ORIGIN" --whole-archive -lLLVMAnalysis -lLLVMAsmParser -lLLVMAsmPrinter
-lLLVMBitReader -lLLVMBitWriter -lLLVMCodeGen -lLLVMCore -lLLVMDebugInfo
-lLLVMExecutionEngine -lLLVMInstCombine -lLLVMInstrumentation
-lLLVMInterpreter -lLLVMipa -lLLVMipo -lLLVMIRReader -lLLVMLinker -lLLVMLTO
-lLLVMMC -lLLVMMCDisassembler -lLLVMMCJIT -lLLVMMCParser -lLLVMObjCARCOpts
-lLLVMObject -lLLVMOption -lLLVMRuntimeDyld -lLLVMScalarOpts
-lLLVMSelectionDAG -lLLVMSupport -lLLVMTarget -lLLVMTransformUtils
-lLLVMVectorize -lLLVMX86AsmParser -lLLVMX86AsmPrinter -lLLVMX86CodeGen
-lLLVMX86Desc -lLLVMX86Disassembler -lLLVMX86Info -lLLVMX86Utils
--no-whole-archive --soname libLLVM-3.5svn.so --no-undefined -lz -ltinfo
-lm -lstdc++ -lm -lgcc_s -lc -lgcc_s
/usr/lib/gcc/x86_64-linux-gnu/4.8/crtendS.o
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crtn.o

It doesn't seem to be linking the asan runtime which seems weird since I'm
passing -faddress=sanitize.


On Thu, Nov 21, 2013 at 5:24 AM, Alexander Potapenko <glider at google.com>wrote:

> On Thu, Nov 21, 2013 at 6:18 AM, Keno Fischer <kfischer at csail.mit.edu>
> wrote:
> > Hello everybody,
> >
> > after moving from OS X to Linux build llvm with asan enabled
> Sorry, I failed to parse this. You're compiling Clang on Linux, and
> OSX is unrelated, right?
> > (I also updated
> > to trunk, but not sure if that's related). However, it's totally possible
> > that I missed a step that I took back when I set this up for me, so I
> might
> > be doing something very stupid. Anyway, I'm configuring LLVM with
> >
> > ../configure --prefix=/home/kfischer/julia/usr
> --build=x86_64-pc-linux-gnu
> > FC=gfortran
> >
> CC="/home/kfischer/julia/deps/llvm-svn/build_Release+Asserts/Release+Asserts/bin/clang
> > -fsanitize=address"
> >
> CXX="/home/kfischer/julia/deps/llvm-svn/build_Release+Asserts/Release+Asserts/bin/clang++"
> > -fsanitize=address --disable-profiling --enable-shared --enable-static
> > --enable-targets=host --disable-bindings --disable-docs
> --enable-assertions
> > --enable-optimized --disable-threads
> So you're building Clang with -fsanitize=address. Note: you won't be
> able to build libsanitizer this way.
>
> > in a different directory (build_Release+Asserts+Sanitize). As you can see
> > I'm bootstrapping this through a different copy of clang I just built.
> > However, now I'm getting tons of
> > undefined reference to `__asan_report_store8'
> > even though the command the failing command being invoked is
> >
> >
> /home/kfischer/julia/deps/llvm-svn/build_Release+Asserts/Release+Asserts/bin/clang++
> > -fsanitize=address   -O3 -Wl,-R -Wl,'$ORIGIN' -rdynamic
> >
> -L/home/kfischer/julia/deps/llvm-svn/build_Release+Asserts+Sanitize/Release+Asserts/lib
> >
> -L/home/kfischer/julia/deps/llvm-svn/build_Release+Asserts+Sanitize/Release+Asserts/lib
> > -shared -o
> >
> /home/kfischer/julia/deps/llvm-svn/build_Release+Asserts+Sanitize/Release+Asserts/lib/
> libLLVM-3.5svn.so
> > -Wl,--whole-archive -lLLVMAnalysis -lLLVMAsmParser -lLLVMAsmPrinter
> > -lLLVMBitReader -lLLVMBitWriter -lLLVMCodeGen -lLLVMCore -lLLVMDebugInfo
> > -lLLVMExecutionEngine -lLLVMInstCombine -lLLVMInstrumentation
> > -lLLVMInterpreter -lLLVMipa -lLLVMipo -lLLVMIRReader -lLLVMLinker
> -lLLVMLTO
> > -lLLVMMC -lLLVMMCDisassembler -lLLVMMCJIT -lLLVMMCParser
> -lLLVMObjCARCOpts
> > -lLLVMObject -lLLVMOption -lLLVMRuntimeDyld -lLLVMScalarOpts
> > -lLLVMSelectionDAG -lLLVMSupport -lLLVMTarget -lLLVMTransformUtils
> > -lLLVMVectorize -lLLVMX86AsmParser -lLLVMX86AsmPrinter -lLLVMX86CodeGen
> > -lLLVMX86Desc -lLLVMX86Disassembler -lLLVMX86Info -lLLVMX86Utils
> > -Wl,--no-whole-archive -Wl,--soname,libLLVM-3.5svn.so-Wl,--no-undefined -lz
> > -ltinfo -lm
>
> Can you please add -v to the command line to see the ld invocation line?
> You'll need to locate the ASan runtime library and check whether it's
> a 32-bit one and if __asan_report_store8 is present in its symbol
> table.
> > Am I doing something stupid?
> > Thanks,
> > Keno
> >
> >
> > _______________________________________________
> > LLVM Developers mailing list
> > LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >
>
>
>
> --
> Alexander Potapenko
> Software Engineer
> Google Moscow
>
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