random: scope environ extern to macOS, BSDs and Illumos #33714

1. 
   fanquake commented at 4:38 pm on October 27, 2025: member

   These platforms fail to compile with it removed. macOS: #33675 BSDs / Illumos: https://github.com/hebasto/bitcoin-core-nightly/pull/79.
2. DrahtBot added the label Utils/log/libs on Oct 27, 2025
3. 
   DrahtBot commented at 4:38 pm on October 27, 2025: contributor

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

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/33714.

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4. hebasto approved
5. 
   hebasto commented at 4:44 pm on October 27, 2025: member

   ACK f24ef2b4e01884ac1dea07ebbc7e7d0aa2c09541.
6. in src/randomenv.cpp:60 in f24ef2b4e0

   57@@ -58,7 +58,7 @@
   58 #endif
   59 
   60 #ifndef WIN32
   

   ---

   ---

   

   l0rinc commented at 7:47 pm on October 27, 2025:

   If it’s only needed on Mac, wouldn’t:

   0#ifdef __APPLE__
   

   be better here?

   ---

   

   fanquake commented at 5:47 pm on October 28, 2025:

   I’m not 100% sure that is the only place it’s needed, however this has historically been unclear, and the only platform I’m aware of that definitely needs it, is macOS.
7. fanquake force-pushed on Oct 28, 2025
8. fanquake renamed this:
   random: clarify where the environ extern is needed
   random: scope the environ extern to macOS
   on Oct 28, 2025
9. DrahtBot renamed this:
   random: scope the environ extern to macOS
   random: scope the environ extern to macOS
   on Oct 28, 2025
10. 
    hebasto commented at 7:58 pm on October 28, 2025: member

    Testing on some other platforms: https://github.com/hebasto/bitcoin-core-nightly/pull/79.
11. 
    hebasto commented at 0:52 am on October 29, 2025: member

    Testing on some other platforms: hebasto/bitcoin-core-nightly#79.

    Builds on the *BSD and illumos systems failed.

12. fanquake force-pushed on Oct 29, 2025
13. fanquake renamed this:
    random: scope the environ extern to macOS
    random: scope environ extern to macOS, BSDs and Illumos
    on Oct 29, 2025
14. in src/randomenv.cpp:61 in fcdbce4a04 outdated

    56@@ -57,8 +57,12 @@
    57 #include <sys/auxv.h>
    58 #endif
    59 
    60-#ifndef WIN32
    61-extern char** environ; // NOLINT(readability-redundant-declaration): Necessary on some platforms
    

    ---

    ---

    

    maflcko commented at 12:52 pm on October 29, 2025:

    nit: I think the comment can be kept as-is, or just refer to “Necessary on the above platforms”. Otherwise, it is just one more line to maintain.

    Also, I wonder if this can just be checked at configure-time, but no strong opinion.

    ---

    

    fanquake commented at 3:14 pm on October 29, 2025:

    Re-modified the comment. Not sure there is too much value in moving this to configure.
15. hebasto approved
16. 
    hebasto commented at 1:41 pm on October 29, 2025: member

    ACK fcdbce4a040e4a40aac9ed5ef8634b09d092063e.
17. random: scope environ extern to macOS, BSDs and Illumos

    These platforms fail to compile with it removed.

    79d6f458e2
18. fanquake force-pushed on Oct 29, 2025

Contributors
fanquake DrahtBot hebasto l0rinc maflcko

Labels
Utils/log/libs