Bug 729268 – sys-libs/compiler-rt-10.0.0 does not provide BlocksRuntime library for -fblocks

• Product: Gentoo Linux
• Status: RESOLVED INVALID

[Description Sergei Trofimovich (RETIRED) 2020-06-23 07:21:49 UTC]

Popped up in https://bugs.gentoo.org/729256 where honggfuzz uses blocks to implement destructors in C on clang.

https://stackoverflow.com/questions/5907071/clang-block-in-linux provides a cmall example that should work:

$ cat c.c
#include <stdio.h>

int main() {
    void (^hello)(void) = ^(void) {
        printf("Hello, block!\n");
    };
    hello();
    return 0;
}

$ LANG=C clang -fblocks c.c -lBlocksRuntime
/usr/lib/gcc/x86_64-pc-linux-gnu/11.0.0/../../../../x86_64-pc-linux-gnu/bin/ld: cannot find -lBlocksRuntime
/usr/lib/gcc/x86_64-pc-linux-gnu/11.0.0/../../../../x86_64-pc-linux-gnu/bin/ld: skipping incompatible libgcc_s.so.1 when searching for libgcc_s.so.1
clang-10: error: linker command failed with exit code 1 (use -v to see invocation)

[Comment 1 Michał Górny 2020-06-23 21:16:41 UTC]

Is it supposed to be provided?  A quick grep over CMakeLists.txt doesn't reveal any rules to build these files.

[Comment 2 Sergei Trofimovich (RETIRED) 2020-06-26 16:08:57 UTC]

Other distributions package it from somewhere else. I can do the same.

[Comment 3 Michał Górny 2020-06-26 17:06:32 UTC]

If 'somewhere else' is a LLVM project, I still think it's better to be maintained by LLVM team.

[Comment 4 Sergei Trofimovich (RETIRED) 2020-06-26 17:08:33 UTC]

It is 6 years old fork of compiler-rt: https://github.com/mackyle/blocksruntime

[Comment 5 Michał Górny 2020-06-26 17:19:11 UTC]

If you have some free time (yeah!), maybe try to submit CMakeLists.txt for building it from compiler-rt ;-).