build: Fix fuzz binary compilation under windows #21226

1. 
   danben commented at 6:38 pm on February 18, 2021: contributor

   Small change to allow the fuzz binary to compile under windows. Also removed –disable-fuzz-binary from the windows CI test. This fixes #21212.
2. in src/test/fuzz/fuzz.cpp:79 in e3da77aa03 outdated

   71@@ -72,7 +72,11 @@ extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv)
   72 }
   73 
   74 #if defined(PROVIDE_MAIN_FUNCTION)
   75+#ifdef WIN32
   76+int main(int argc, char** argv)
   77+#else
   78 __attribute__((weak)) int main(int argc, char** argv)
   79+#endif
   

   ---

   ---

   

   MarcoFalke commented at 6:48 pm on February 18, 2021:

   0#ifndef WIN32
   1__attribute__((weak))
   2#endif
   3int main(int argc, char** argv)
   

   ---

   

   MarcoFalke commented at 6:49 pm on February 18, 2021:

   Haven’t tried this, but with one less line of code you could achieve the same?
3. 
   MarcoFalke commented at 6:49 pm on February 18, 2021: member

   Nice find. Is this a feature or a bug of windows?
4. MarcoFalke approved
5. 
   danben commented at 7:08 pm on February 18, 2021: contributor

   Nice find. Is this a feature or a bug of windows?

   Good question. I’m no Windows programmer but this and designated initializers came up when I initially tackled the fuzz binary thing. According to Wikipedia, weak symbols are specific to ELF. According to this thread, MinGW has supported weak symbols for some time but I guess people have problems with it. My understanding is that no one is trying to build for fuzzing on Windows so it seemed fine to just omit the annotation.

6. 
   MarcoFalke commented at 8:14 pm on February 18, 2021: member

   No need to attribute me. And please squash your commits according to https://github.com/bitcoin/bitcoin/blob/master/CONTRIBUTING.md#squashing-commits
7. in src/test/fuzz/fuzz.cpp:76 in 5d9999aac9 outdated

   71@@ -72,7 +72,10 @@ extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv)
   72 }
   73 
   74 #if defined(PROVIDE_MAIN_FUNCTION)
   75-__attribute__((weak)) int main(int argc, char** argv)
   76+#ifndef WIN32
   77+__attribute__((weak))
   

   ---

   ---

   

   MarcoFalke commented at 8:21 pm on February 18, 2021:

   Hmm, I think we don’t even need the attribute at all, now that we have a proper configure check.

   • Afl does need the main function (preferably without the attribute)
   • honggfuzz and libFuzzer shouldn’t get it
   • raw builds need the main function (preferably without the attribute)

   ---

   

   danben commented at 8:22 pm on February 18, 2021:

   That sounds right. Perhaps that will save me from having to figure out where this mac failure is coming from.
8. DrahtBot added the label Build system on Feb 18, 2021
9. Fix fuzz binary compilation under windows 56ace907b9
10. danben force-pushed on Feb 18, 2021
11. 
    DrahtBot commented at 4:28 am on February 19, 2021: member

    The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

    Conflicts

    Reviewers, this pull request conflicts with the following ones:

    • #21003 (test: Move MakeNoLogFileContext to libtest_util, and use it in bench by MarcoFalke)

    If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

12. 
    MarcoFalke commented at 8:25 am on February 19, 2021: member

    review ACK 56ace907b9b7b4544c95e2945dc07e217718a8e5 the best bugfixes are the ones removing code
13. MarcoFalke merged this on Feb 19, 2021
14. MarcoFalke closed this on Feb 19, 2021

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15. danben deleted the branch on Feb 19, 2021
16. sidhujag referenced this in commit b9208c562c on Feb 19, 2021
17. DrahtBot locked this on Aug 16, 2022

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