mirror of
https://github.com/capstone-engine/llvm-capstone.git
synced 2025-02-09 10:55:03 +00:00
8883ec7da2
When ld64 links a binary deterministically using the flag ZERO_AR_DATE, it sets a timestamp of 0 for N_OSO members in the symtab section, rather than the usual last modified date of the object file. Prior to this patch, lldb would compare the timestamp from the N_OSO member against the last modified date of the object file, and skip loading the object file if there was a mismatch. This patch updates the logic to ignore the timestamp check if the N_OSO member has timestamp 0. The original logic was added in https://reviews.llvm.org/rL181631 as a safety check to avoid problems when debugging if the object file was out of date. This was prior to the introduction of deterministic build in ld64. lld still doesn't support deterministic build. Other code in llvm already relies on and uses the assumption that a timestamp of 0 means deterministic build. For example, commit 9ccfddc39d4d27f9b16fcc72ab30d483151d6d08 adds similar timestamp checking logic to dsymutil, but special cases timestamp 0. Likewise, commit 0d1bb79a0413f221432a7b1d0d2d10c84c4bbb99 adds a long comment describing deterministic archive, which mostly uses timestamp 0 for determinism. Patch from Erik Chen <erikchen@chromium.org>! Differential Revision: https://reviews.llvm.org/D65826 llvm-svn: 368199