Author: Eli Friedman Date: 2022-04-18T17:05:35-07:00 New Revision: e8f03f2057ee783439229391a14b2ffe17346100
URL: https://github.com/llvm/llvm-project/commit/e8f03f2057ee783439229391a14b2ffe17346100 DIFF: https://github.com/llvm/llvm-project/commit/e8f03f2057ee783439229391a14b2ffe17346100.diff LOG: Force GHashCell to be 8-byte-aligned. Otherwise, with recent versions of libstdc++, clang can't tell that the atomic operations are properly aligned, and generates calls to libatomic. (Actually, because of the use of reinterpret_cast, it wasn't guaranteed to be aligned, but I think it ended up being aligned in practice.) Fixes https://github.com/llvm/llvm-project/issues/54790 , the part where LLVM failed to build. Differential Revision: https://reviews.llvm.org/D123872 (cherry picked from commit 13fc1781735a327699d9522e8e44899acf92a61a) Added: Modified: lld/COFF/DebugTypes.cpp Removed: ################################################################################ diff --git a/lld/COFF/DebugTypes.cpp b/lld/COFF/DebugTypes.cpp index aa2ce3bd9bbbf..0d25de464f9f6 100644 --- a/lld/COFF/DebugTypes.cpp +++ b/lld/COFF/DebugTypes.cpp @@ -902,7 +902,11 @@ struct GHashTable { /// A ghash table cell for deduplicating types from TpiSources. class GHashCell { - uint64_t data = 0; + // Force "data" to be 64-bit aligned; otherwise, some versions of clang + // will generate calls to libatomic when using some versions of libstdc++ + // on 32-bit targets. (Also, in theory, there could be a target where + // new[] doesn't always return an 8-byte-aligned allocation.) + alignas(sizeof(uint64_t)) uint64_t data = 0; public: GHashCell() = default; _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
