zig cc -fsanatize=address fails at link time on macOS

[drfuchs]

Zig Version

0.10.0-dev.1736+93e11b824

Steps to Reproduce

zig cc -fsanitize=address hello.c

Tried on "Apple M1 Pro macOS Monterey 12.3.1" as well as "Intel Core i7 macOS Catalina 10.15.7"

Expected Behavior

Joy in Mudville

Actual Behavior

zig cc -fsanitize=address hello.c error(link): undefined reference to symbol '___asan_init' error(link): first referenced in '/Users/elided/.cache/zig/o/elided/hello.o' error(link): undefined reference to symbol '___asan_register_image_globals' error(link): first referenced in '/Users/elided/.cache/zig/o/elided/hello.o' error(link): undefined reference to symbol '___asan_unregister_image_globals' error(link): first referenced in '/Users/elided/.cache/zig/o/elided/hello.o' error(link): undefined reference to symbol '___asan_version_mismatch_check_v8' error(link): first referenced in '/Users/elided/.cache/zig/o/elided/hello.o' error: UndefinedSymbolReference

(On macOS Monterey, it also first complained: warning(link): directory not found for '-L/usr/local/lib' for what that's worth.)

[moosichu]

This is related to #5163 and #10374 - although applying to asan instead of ubsan.

[drfuchs]

(Just to add more color to this bug / lack of feature, in case it affects its prioritization:)

This issue interferes with Zig's "Maintain it with Zig: Incrementally improve your C/C++/Zig codebase" story.

Most directly, you can't use the advertised "drop-in C/C++ compiler" functionality of Zig for developing stand-alone C code while asan detection is crucial. So all the fabulous advantages of being able to do so disappear.

More importantly, it also seems to interfere with taking existing C codebases that are in pretty good but perhaps not immaculate condition, and trying to incrementally port them to Zig: How can I compile and link and run such that something is keeping an eye on the malloc'd pointers used by the C code at runtime, while still being able to call into / out of Zig code that's also compiled in debug mode? Or even if my C code is perfect, perhaps I might call it in an incorrect way from my new Zig code, causing the C code to, say, dereference a free pointer, which still needs detecting.

I'm willing to make any C-world pointer that round-trips through Zig code be a pointer to a type that's opaque to my Zig code (so that they never get dereferenced directly in the Zig code, and thus need no asan-like checking there), if that helps; or use something other than malloc/free from C; or whatever else might do the trick.

Or did I perhaps miss the boat, and there's a currently-supported way to handle this, perhaps using regular "cc -fsanitize=address" on the C code, and "zig build-obj" on the zig code, and who-knows-what linker to put it all together (and pray that there are no conflicts about who owns main() and whose crt startup code gets included and what libraries I have to explicitly include, and etc.)? Will the solution work across platforms, even ignoring cross-compilation?

FWIW, I'm way more concerned about asan than general ubsan detection, based on the difficulty of tracking down the bugs that result when not automatically detected at the moment of initial transgression.

[prenaux]

I'll link https://github.com/ziglang/zig/issues/12992 here since I feel its related - to fully support C++ in zigcc on all targets.

[chadbrewbaker]

Here is how Apple is driving it in their unit tests, https://github.com/apple-oss-distributions/libmalloc/blob/387a5a03c017801ecdfe9cbe7f8d69a9b427df68/tests/asan.c#L13

Another reason why it would be nice to have all of MacOS libsystem building statically, so Zig could re-use Apple's own tests.

[chrisirhc]

Reproducible on linux x86_64 so this is not a macos-specific issue:

 % ./zig-linux-x86_64-0.11.0-dev.2368+f4b411314/zig cc -fsanitize=address  hello.c
LLD Link... ld.lld: error: undefined symbol: __asan_init
>>> referenced by hello.c
>>>               /home/user/.cache/zig/o/35face62758b9eaf253cfae70bafbb87/hello.o:(asan.module_ctor)

ld.lld: error: undefined symbol: __asan_version_mismatch_check_v8
>>> referenced by hello.c
>>>               /home/user/.cache/zig/o/35face62758b9eaf253cfae70bafbb87/hello.o:(asan.module_ctor)

ld.lld: error: undefined symbol: __asan_register_globals
>>> referenced by hello.c
>>>               /home/user/.cache/zig/o/35face62758b9eaf253cfae70bafbb87/hello.o:(asan.module_ctor)

ld.lld: error: undefined symbol: __asan_unregister_globals
>>> referenced by hello.c
>>>               /home/user/.cache/zig/o/35face62758b9eaf253cfae70bafbb87/hello.o:(asan.module_dtor)

[g-berthiaume]

I had the same issue on windows 11

Please note that, the same command works with clang but not zig cc.

# Will work
$ clang .\main.c .\pingpong.c -Wall -Wextra -Wpedantic -fsanitize=address -O0 -g3 -o .\appb.exe
   Creating library .\appb.lib and object .\appb.exp
# Will fail
$ zig cc .\main.c .\pingpong.c -Wall -Wextra -Wpedantic -fsanitize=address -O0 -g3 -o .\appb.exe
LLD Link... lld-link: error: undefined symbol: __asan_report_load1
[....]

Here's some info about my setup:

[Warchant]

I had the same issue on windows 11

Please note that, the same command works with clang but not zig cc.

# Will work
$ clang .\main.c .\pingpong.c -Wall -Wextra -Wpedantic -fsanitize=address -O0 -g3 -o .\appb.exe
   Creating library .\appb.lib and object .\appb.exp
# Will fail
$ zig cc .\main.c .\pingpong.c -Wall -Wextra -Wpedantic -fsanitize=address -O0 -g3 -o .\appb.exe
LLD Link... lld-link: error: undefined symbol: __asan_report_load1
[....]

Here's some info about my setup:

I just added -L$(ASAN_DIR) and -lasan to link flags, and now asan works. (Windows11, inside WSL2).

$ cat 1.cpp
#include <cstdio>

int main() {
    printf("Hello World!\n");
    new int;
    return 0;
}
$ find /usr/lib -type f -name "libasan.*"
/usr/lib/gcc/x86_64-linux-gnu/11/libasan.a
/usr/lib/x86_64-linux-gnu/libasan.so.6.0.0
$ zig c++ -L/usr/lib/gcc/x86_64-linux-gnu/11 -lasan -fsanitize=address -o zig_bin 1.cpp
$ ./zig_bin
Hello World!

=================================================================
==10112==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 4 byte(s) in 1 object(s) allocated from:
    #0 0x7f8a2046a1e7 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cpp:99
    #1 0x201766 in main /mnt/c/W/cli/1/1.cpp:5
    #2 0x7f8a201b5d8f  (/lib/x86_64-linux-gnu/libc.so.6+0x29d8f)

SUMMARY: AddressSanitizer: 4 byte(s) leaked in 1 allocation(s).

[g-berthiaume]

I just added -L$(ASAN_DIR) and -lasan to link flags, and now asan works. (Windows11, inside WSL2).

Hi @Warchant. Thanks for your feedback. It also worked on my machine when using those flags:

zig cc main.c -L/usr/lib/gcc/x86_64-linux-gnu/11/ -lasan -fsanitize=address -o main