build: enable `-Wunreachable-code-aggressive` #36623

pull fanquake wants to merge 4 commits into bitcoin:master from fanquake:unreachable_aggressive changing 6 files +11 −7

fanquake commented at 2:12 PM on October 23, 2026: member
Swap -Wunreachable-code for -Wunreachable-code-aggressive which also enables -Wunreachable-code-return and -Wunreachable-code-break.

Based on:
- https://github.com/bitcoin-core/leveldb-subtree/pull/66.
[nomerge] leveldb changes d641412836
[nomerge] minisketch changes 25f2200215
refactor: fix -Wunreachable-code-aggressive warnings 0acc4d0eb6

build: swap -Wunreachable-code for aggressive variant

Enables `-Wunreachable-code-break` and `-Wunreachable-code-return`.

8f8ea0b2af

DrahtBot added the label Build system on Oct 23, 2026
DrahtBot commented at 2:12 PM on October 23, 2026: contributor


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- Code coverage & benchmarks: https://corecheck.dev/bitcoin/bitcoin/pulls/36623
- Ralph review <img src=https://review.fish.foo/assets/bitcoin/bitcoin/36623.png alt="Ralph review status"> https://git.fish.foo/bitcoin/bitcoin/pulls/36623#author-ralph


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in src/script/interpreter.cpp:685 in 8f8ea0b2af

 677 | @@ -678,7 +678,14 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
 678 |                  {
 679 |                      return set_error(serror, SCRIPT_ERR_OP_RETURN);
 680 |                  }
 681 | +#if defined(__clang__)
 682 | +#pragma clang diagnostic push
 683 | +#pragma clang diagnostic ignored "-Wunreachable-code-break"
 684 | +#endif
 685 |                  break;

willcl-ark commented at 2:57 PM on October 23, 2026:

It does appear that this is likely removable too.

DrahtBot added the label CI failed on Oct 23, 2026
DrahtBot commented at 3:20 PM on October 23, 2026: contributor


🚧 At least one of the CI tasks failed. <sub>Task lint: https://github.com/bitcoin/bitcoin/actions/runs/39967612158/job/120461497226</sub> <sub>LLM reason (✨ experimental): CI failed the subtree lint check because the LevelDB and minisketch subtrees were modified without a subtree merge.</sub>

<details><summary>Hints</summary>

Try to run the tests locally, according to the documentation. However, a CI failure may still happen due to a number of reasons, for example:
- Possibly due to a silent merge conflict (the changes in this pull request being incompatible with the current code in the target branch). If so, make sure to rebase on the latest commit of the target branch.
- A sanitizer issue, which can only be found by compiling with the sanitizer and running the affected test.
- An intermittent issue.
Leave a comment here, if you need help tracking down a confusing failure.

</details>

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Build system CI failed

build: enable `-Wunreachable-code-aggressive` #36623

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