From d6d3d96b654012d72ad170d272cb2fe2c8def90d Mon Sep 17 00:00:00 2001 From: Orlando Cazalet-Hyams Date: Fri, 15 Mar 2024 10:47:48 +0000 Subject: [RemoveDIs] Read/write DbgRecords directly from/to bitcode (#83251) If --write-experimental-debuginfo-iterators-to-bitcode is true (default false) and --expermental-debuginfo-iterators is also true then the new debug info format (non-instruction records) is written to bitcode directly. Added the following records: FUNC_CODE_DEBUG_RECORD_LABEL FUNC_CODE_DEBUG_RECORD_VALUE FUNC_CODE_DEBUG_RECORD_DECLARE FUNC_CODE_DEBUG_RECORD_ASSIGN FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE The last one has an abbrev in FUNCTION_BLOCK BLOCK_INFO. Incidentally, this uses the last value available without widening the code-length for FUNCTION_BLOCK from 4 to 5 bits. Records are formatted as follows: All DbgRecord start with: 1. DILocation FUNC_CODE_DEBUG_RECORD_LABEL 2. DILabel DPValues then share common fields: 2. DILocalVariable 3. DIExpression FUNC_CODE_DEBUG_RECORD_VALUE 4. Location Metadata FUNC_CODE_DEBUG_RECORD_DECLARE 4. Location Metadata FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE 4. Location Value (single) FUNC_CODE_DEBUG_RECORD_ASSIGN 4. Location Metadata 5. DIAssignID 6. DIExpression (address) 7. Location Metadata (address) Encoding the DILocation metadata reference directly appeared to yield smaller bitcode files than encoding the operands seperately (as is done with instruction DILocations). FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE is by far the most common DbgRecord record in optimized code (order of 5x-10x over other kinds). Unoptimized code should only contain FUNC_CODE_DEBUG_RECORD_DECLARE. --- llvm/lib/Bitcode/Writer/BitcodeWriterPass.cpp | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'llvm/lib/Bitcode/Writer/BitcodeWriterPass.cpp') diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriterPass.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriterPass.cpp index 0eb9c246f2a9..de2396f31f66 100644 --- a/llvm/lib/Bitcode/Writer/BitcodeWriterPass.cpp +++ b/llvm/lib/Bitcode/Writer/BitcodeWriterPass.cpp @@ -18,11 +18,12 @@ #include "llvm/Pass.h" using namespace llvm; +extern bool WriteNewDbgInfoFormatToBitcode; + PreservedAnalyses BitcodeWriterPass::run(Module &M, ModuleAnalysisManager &AM) { - // RemoveDIs: there's no bitcode representation of the DbgRecord debug-info, - // convert to dbg.values before writing out. - bool IsNewDbgInfoFormat = M.IsNewDbgInfoFormat; - if (IsNewDbgInfoFormat) + bool ConvertToOldDbgFormatForWrite = + M.IsNewDbgInfoFormat && !WriteNewDbgInfoFormatToBitcode; + if (ConvertToOldDbgFormatForWrite) M.convertFromNewDbgValues(); const ModuleSummaryIndex *Index = @@ -30,7 +31,7 @@ PreservedAnalyses BitcodeWriterPass::run(Module &M, ModuleAnalysisManager &AM) { : nullptr; WriteBitcodeToFile(M, OS, ShouldPreserveUseListOrder, Index, EmitModuleHash); - if (IsNewDbgInfoFormat) + if (ConvertToOldDbgFormatForWrite) M.convertToNewDbgValues(); return PreservedAnalyses::all(); @@ -56,16 +57,15 @@ namespace { StringRef getPassName() const override { return "Bitcode Writer"; } bool runOnModule(Module &M) override { - // RemoveDIs: there's no bitcode representation of the DbgRecord - // debug-info, convert to dbg.values before writing out. - bool IsNewDbgInfoFormat = M.IsNewDbgInfoFormat; - if (IsNewDbgInfoFormat) + bool ConvertToOldDbgFormatForWrite = + M.IsNewDbgInfoFormat && !WriteNewDbgInfoFormatToBitcode; + if (ConvertToOldDbgFormatForWrite) M.convertFromNewDbgValues(); WriteBitcodeToFile(M, OS, ShouldPreserveUseListOrder, /*Index=*/nullptr, /*EmitModuleHash=*/false); - if (IsNewDbgInfoFormat) + if (ConvertToOldDbgFormatForWrite) M.convertToNewDbgValues(); return false; } -- cgit v1.2.3