From fb8557813afd41e09b4ba20091adf6b803967112 Mon Sep 17 00:00:00 2001 From: Ulrich Weigand Date: Thu, 27 Apr 2023 17:45:25 +0200 Subject: Fix PDB relocation on big-endian hosts When running the LLD test suite on a big-endian host, the COFF/pdb-framedata.yaml test case currently fails. As it turns out, this is because code in DebugSHandler::finish intended to relocate RvaStart entries of FDO records does not work correctly when compiled for a big-endian host. Fixed by always reading file data in little-endian mode. Reviewed By: aganea Differential Revision: https://reviews.llvm.org/D149268 --- lld/COFF/PDB.cpp | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'lld') diff --git a/lld/COFF/PDB.cpp b/lld/COFF/PDB.cpp index 94af920d5e7a..8ca74ebc661e 100644 --- a/lld/COFF/PDB.cpp +++ b/lld/COFF/PDB.cpp @@ -950,7 +950,7 @@ void DebugSHandler::finish() { // must also be rewritten to use the PDB string table. for (const UnrelocatedFpoData &subsec : frameDataSubsecs) { // Relocate the first four bytes of the subection and reinterpret them as a - // 32 bit integer. + // 32 bit little-endian integer. SectionChunk *debugChunk = subsec.debugChunk; ArrayRef subsecData = subsec.subsecData; uint32_t relocIndex = subsec.relocIndex; @@ -959,8 +959,9 @@ void DebugSHandler::finish() { debugChunk->writeAndRelocateSubsection(debugChunk->getContents(), unrelocatedRvaStart, relocIndex, &relocatedRvaStart[0]); - uint32_t rvaStart; - memcpy(&rvaStart, &relocatedRvaStart[0], sizeof(uint32_t)); + // Use of memcpy here avoids violating type-based aliasing rules. + support::ulittle32_t rvaStart; + memcpy(&rvaStart, &relocatedRvaStart[0], sizeof(support::ulittle32_t)); // Copy each frame data record, add in rvaStart, translate string table // indices, and add the record to the PDB. -- cgit v1.2.1