Search code examples
cvisual-studioqtaddress-sanitizercl

VC2019 address sanitizer 64 bit link error on windows "unresolved external symbol __asan_shadow_memory_dynamic_address"

The following simple program

#include <malloc.h>
int main(int argc, char **argv)
{
    char* arr=malloc(10);
    arr[10]='\0';
    return 0;
}

builds fine with VC2019 16.8.2 in 32 bit dynamic linking

cl -Zi -fsanitize=address -MD clang_rt.asan_dynamic-i386.lib xx.c

and reports the memory error when running the program. However when using the 64bit variant I get a linking error

> cl -Zi -fsanitize=address -MD clang_rt.asan_dynamic-x86_64.lib xx.c
Microsoft (R) C/C++ Optimizing Compiler Version 19.28.29336 for x64
Copyright (C) Microsoft Corporation.  All rights reserved.

xx.c
Microsoft (R) Incremental Linker Version 14.28.29336.0
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:xx.exe
/debug
clang_rt.asan_dynamic-x86_64.lib
xx.obj
xx.obj : error LNK2019: unresolved external symbol __asan_shadow_memory_dynamic_address referenced in function main
xx.exe : fatal error LNK1120: 1 unresolved externals

Looking in the clang_rt.asan_dynamic-x86_64.lib with dumpbin the missing symbol appears. Note that on both architectures static linking of the sample (without the _dynamic libs) works, but I need dynamic linking because of larger dependencies (Qt dlls). Anyone stumbled across that already ?

Regards, Leo

Solution

  • Turned out that I needed to add linking to a second lib as well; clang_rt.asan_dynamic_runtime_thunk-x86_64.lib, and not just the standard asan runtime.

    cl -MD -fsanitize=address \
    clang_rt.asan_dynamic-x86_64.lib \
    clang_rt.asan_dynamic_runtime_thunk-x86_64.lib xx.c

    The above command links the program correctly and brings up the sanitizer error after starting the program. One can find the corresponding build models to asan lib mappings at the following link.