refactor: Use immediate lambda to work around GCC bug 117966 #31493

1. 
   maflcko commented at 2:46 pm on December 13, 2024: member

   Currently the libstdc++ debug mode can only be used with version 11, or 15 (and later), due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117966

   This seems restrictive.

   Add a temporary workaround for now, which makes the global (temporary) std::span local to a lambda.

2. 
   DrahtBot commented at 2:56 pm on December 13, 2024: contributor

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   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/31493.

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3. DrahtBot added the label Refactoring on Dec 13, 2024
4. in src/pubkey.cpp:195 in fa12290549 outdated

   191@@ -192,7 +192,10 @@ int ecdsa_signature_parse_der_lax(secp256k1_ecdsa_signature* sig, const unsigned
   192  *  For an example script for calculating H, refer to the unit tests in
   193  *  ./test/functional/test_framework/crypto/secp256k1.py
   194  */
   195-constexpr XOnlyPubKey XOnlyPubKey::NUMS_H{"50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac0"_hex_u8};
   196+constexpr XOnlyPubKey XOnlyPubKey::NUMS_H{
   

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   theuni commented at 6:14 pm on December 13, 2024:

   Nice hack. Could use consteval on the lambda to enforce compile-time

   0constexpr XOnlyPubKey XOnlyPubKey::NUMS_H{
   1    // Use immediate lambda to work around GCC-14 bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117966
   2    []() consteval { return XOnlyPubKey{"50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac0"_hex_u8}; }(),
   3};
   

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   maflcko commented at 10:17 am on December 16, 2024:

   I left it out to let the compiler decide whether to use it or not, just like before.

   Though, pushed consteval now, thx!

5. 
   theuni commented at 6:18 pm on December 13, 2024: member

   Concept ACK
6. refactor: Use immediate lambda to work around GCC bug 117966 fa9e0489f5
7. maflcko force-pushed on Dec 16, 2024
8. theuni approved
9. 
   theuni commented at 5:04 pm on December 16, 2024: member

   utACK fa9e0489f57968945d54ef56b275f51540f3e5e4
10. in src/pubkey.cpp:196 in fa9e0489f5

    191@@ -192,7 +192,10 @@ int ecdsa_signature_parse_der_lax(secp256k1_ecdsa_signature* sig, const unsigned
    192  *  For an example script for calculating H, refer to the unit tests in
    193  *  ./test/functional/test_framework/crypto/secp256k1.py
    194  */
    195-constexpr XOnlyPubKey XOnlyPubKey::NUMS_H{"50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac0"_hex_u8};
    196+constexpr XOnlyPubKey XOnlyPubKey::NUMS_H{
    197+    // Use immediate lambda to work around GCC-14 bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117966
    

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    hebasto commented at 11:39 am on December 17, 2024:

    nit: GCC-12 and GCC-13 seem also affected.

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    fanquake commented at 11:43 am on December 17, 2024:

    That is documented in the link and PR description.

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    maflcko commented at 11:48 am on December 17, 2024:

    nit: GCC-12 and GCC-13 seem also affected.

    The code is intentional, to only mention the last version of gcc where the workaround is needed. I don’t see the value to mention more than that.

11. hebasto approved
12. 
    hebasto commented at 11:39 am on December 17, 2024: member

    ACK fa9e0489f57968945d54ef56b275f51540f3e5e4, tested on Ubuntu 24.10.
13. vasild approved
14. 
    vasild commented at 2:07 pm on December 17, 2024: contributor

    ACK fa9e0489f57968945d54ef56b275f51540f3e5e4
15. ryanofsky merged this on Dec 17, 2024
16. ryanofsky closed this on Dec 17, 2024

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17. maflcko deleted the branch on Dec 18, 2024

Contributors
maflcko DrahtBot theuni hebasto fanquake vasild

Labels
Refactoring