Author: Jan Svoboda Date: 2023-08-28T13:18:40-07:00 New Revision: dd850f0bae8f38b721e9ae6b8ba915dbf7d9bac7
URL: https://github.com/llvm/llvm-project/commit/dd850f0bae8f38b721e9ae6b8ba915dbf7d9bac7 DIFF: https://github.com/llvm/llvm-project/commit/dd850f0bae8f38b721e9ae6b8ba915dbf7d9bac7.diff LOG: [llvm][clang][modules] Fix test failure on big-endian bots After 6fb08d8f558a6f28db7835acdb88cab83aea2eb4,`clang/test/Modules/ModuleDebugInfoDwoId.cpp` started failing on a number of big-endian build bots (clang-ppc64be-linux-multistage, clang-ppc64be-linux-test-suite). This patch attempts to fix that by creating an API on `llvm::BitstreamWriter` that allows backpatching individual bytes. This API is then used from `clang::ASTWriter` to avoid endianness mismatch. Added: Modified: clang/lib/Serialization/ASTWriter.cpp llvm/include/llvm/Bitstream/BitstreamWriter.h Removed: ################################################################################ diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp index c9148b67c06ea9..8eac78408188d2 100644 --- a/clang/lib/Serialization/ASTWriter.cpp +++ b/clang/lib/Serialization/ASTWriter.cpp @@ -1148,13 +1148,9 @@ ASTFileSignature ASTWriter::backpatchSignature() { // For implicit modules, write the hash of the PCM as its signature. auto BackpatchSignatureAt = [&](const ASTFileSignature &S, uint64_t BitNo) { - using WordT = unsigned; - std::array<WordT, sizeof(ASTFileSignature) / sizeof(WordT)> Words; - static_assert(sizeof(Words) == sizeof(S)); - std::memcpy(Words.data(), S.data(), sizeof(ASTFileSignature)); - for (WordT Word : Words) { - Stream.BackpatchWord(BitNo, Word); - BitNo += sizeof(WordT) * 8; + for (uint8_t Byte : S) { + Stream.BackpatchByte(BitNo, Byte); + BitNo += 8; } }; diff --git a/llvm/include/llvm/Bitstream/BitstreamWriter.h b/llvm/include/llvm/Bitstream/BitstreamWriter.h index d802b73e97e0f5..423af4c2cc6c00 100644 --- a/llvm/include/llvm/Bitstream/BitstreamWriter.h +++ b/llvm/include/llvm/Bitstream/BitstreamWriter.h @@ -129,20 +129,20 @@ class BitstreamWriter { // Basic Primitives for emitting bits to the stream. //===--------------------------------------------------------------------===// - /// Backpatch a 32-bit word in the output at the given bit offset - /// with the specified value. - void BackpatchWord(uint64_t BitNo, unsigned NewWord) { + /// Backpatch a byte in the output at the given bit offset with the specified + /// value. + void BackpatchByte(uint64_t BitNo, uint8_t NewByte) { using namespace llvm::support; uint64_t ByteNo = BitNo / 8; uint64_t StartBit = BitNo & 7; uint64_t NumOfFlushedBytes = GetNumOfFlushedBytes(); if (ByteNo >= NumOfFlushedBytes) { - assert((!endian::readAtBitAlignment<uint32_t, little, unaligned>( + assert((!endian::readAtBitAlignment<uint8_t, little, unaligned>( &Out[ByteNo - NumOfFlushedBytes], StartBit)) && "Expected to be patching over 0-value placeholders"); - endian::writeAtBitAlignment<uint32_t, little, unaligned>( - &Out[ByteNo - NumOfFlushedBytes], NewWord, StartBit); + endian::writeAtBitAlignment<uint8_t, little, unaligned>( + &Out[ByteNo - NumOfFlushedBytes], NewByte, StartBit); return; } @@ -151,8 +151,8 @@ class BitstreamWriter { uint64_t CurPos = FS->tell(); // Copy data to update into Bytes from the file FS and the buffer Out. - char Bytes[9]; // Use one more byte to silence a warning from Visual C++. - size_t BytesNum = StartBit ? 8 : 4; + char Bytes[3]; // Use one more byte to silence a warning from Visual C++. + size_t BytesNum = StartBit ? 2 : 1; size_t BytesFromDisk = std::min(static_cast<uint64_t>(BytesNum), NumOfFlushedBytes - ByteNo); size_t BytesFromBuffer = BytesNum - BytesFromDisk; @@ -170,14 +170,14 @@ class BitstreamWriter { assert(BytesRead >= 0 && static_cast<size_t>(BytesRead) == BytesFromDisk); for (size_t i = 0; i < BytesFromBuffer; ++i) Bytes[BytesFromDisk + i] = Out[i]; - assert((!endian::readAtBitAlignment<uint32_t, little, unaligned>( + assert((!endian::readAtBitAlignment<uint8_t, little, unaligned>( Bytes, StartBit)) && "Expected to be patching over 0-value placeholders"); } // Update Bytes in terms of bit offset and value. - endian::writeAtBitAlignment<uint32_t, little, unaligned>(Bytes, NewWord, - StartBit); + endian::writeAtBitAlignment<uint8_t, little, unaligned>(Bytes, NewByte, + StartBit); // Copy updated data back to the file FS and the buffer Out. FS->seek(ByteNo); @@ -189,6 +189,16 @@ class BitstreamWriter { FS->seek(CurPos); } + void BackpatchHalfWord(uint64_t BitNo, uint16_t Val) { + BackpatchByte(BitNo, (uint8_t)Val); + BackpatchByte(BitNo + 8, (uint8_t)(Val >> 8)); + } + + void BackpatchWord(uint64_t BitNo, unsigned Val) { + BackpatchHalfWord(BitNo, (uint16_t)Val); + BackpatchHalfWord(BitNo + 16, (uint16_t)(Val >> 16)); + } + void BackpatchWord64(uint64_t BitNo, uint64_t Val) { BackpatchWord(BitNo, (uint32_t)Val); BackpatchWord(BitNo + 32, (uint32_t)(Val >> 32)); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
