See also google/oss-fuzz#5879

Concept ACK guessing this needs to use a newer Clang:
https://github.com/bitcoin/bitcoin/pull/22841/checks?check_run_id=3471928307

configure: error: unrecognized option: `-ftrivial-auto-var-init=pattern'

configure: error

Fixed

cc @guidovranken @agroce

This would catch the bug fixed in commit 3737126 . (Memory sanitizers also do that, but there shouldn't be any risk in making our asan config catch it as well.)

Interesting. I wrote a tiny section about the -ftrivial-auto-var-init=pattern option and listed some resources about default initialization (including a good list of pros/cons in #17627 (comment) by @practicalswift) a couple years ago in the notes of https://bitcoincore.reviews/17639 to try to understand some of its tradeoffs:

• Pre-initialize variables with dummy values, e.g. compile with Clang -ftrivial-auto-var-init=pattern.
  • Testing sensitivity concerns, e.g. Suppress false positive warning about uninitialized entropy buffers #17627 (comment) by Gregory Maxwell.
  • If a flaw is introduced, it may be undetectable by valgrind.
  • Compilers can warn when they're certain a value will be
    undefined, and pre-emptive dummy initialization suppresses those warnings.
  • Valgrind has special macros that can be used to mark memory as undefined. It
    may be best if dummy initialization were to be always done via a macro that
    would allow disabling it for testing, or valgrind annotating it.

Concept ACK on running the option on its own in a CI task, for IIUC that would avoid the potential drawbacks.

I don't think those tradeoffs are relevant to the discussion here. valgrind (and other memory sanitizers) are already incompatible with asan, as mentioned in the OP.

I don't think those tradeoffs are relevant to the discussion here. valgrind (and other memory sanitizers) are already incompatible with asan, as mentioned in the OP.

I thought the information could be interesting for reviewers interested to learn more.

Ah yes, for general background information on the topic that serves as a good starting point.

cr ACK fa0a5fa