| //===- DebugTranslation.cpp - MLIR to LLVM Debug conversion ---------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "DebugTranslation.h" |
| #include "mlir/Dialect/LLVMIR/LLVMDialect.h" |
| #include "llvm/IR/Metadata.h" |
| #include "llvm/IR/Module.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/Path.h" |
| |
| using namespace mlir; |
| using namespace mlir::LLVM; |
| using namespace mlir::LLVM::detail; |
| |
| /// A utility walker that interrupts if the operation has valid debug |
| /// information. |
| static WalkResult interruptIfValidLocation(Operation *op) { |
| return op->getLoc().isa<UnknownLoc>() ? WalkResult::advance() |
| : WalkResult::interrupt(); |
| } |
| |
| DebugTranslation::DebugTranslation(Operation *module, llvm::Module &llvmModule) |
| : builder(llvmModule), llvmCtx(llvmModule.getContext()), |
| compileUnit(nullptr) { |
| |
| // If the module has no location information, there is nothing to do. |
| if (!module->walk(interruptIfValidLocation).wasInterrupted()) |
| return; |
| |
| // TODO: Several parts of this are incorrect. Different source |
| // languages may interpret different parts of the debug information |
| // differently. Frontends will also want to pipe in various information, like |
| // flags. This is fine for now as we only emit line-table information and not |
| // types or variables. This should disappear as the debug information story |
| // evolves; i.e. when we have proper attributes for LLVM debug metadata. |
| compileUnit = builder.createCompileUnit( |
| llvm::dwarf::DW_LANG_C, |
| builder.createFile(llvmModule.getModuleIdentifier(), "/"), |
| /*Producer=*/"mlir", /*isOptimized=*/true, /*Flags=*/"", /*RV=*/0); |
| |
| // Mark this module as having debug information. |
| StringRef debugVersionKey = "Debug Info Version"; |
| if (!llvmModule.getModuleFlag(debugVersionKey)) |
| llvmModule.addModuleFlag(llvm::Module::Warning, debugVersionKey, |
| llvm::DEBUG_METADATA_VERSION); |
| |
| if (auto targetTripleAttr = |
| module->getAttr(LLVM::LLVMDialect::getTargetTripleAttrName())) { |
| auto targetTriple = |
| llvm::Triple(targetTripleAttr.cast<StringAttr>().getValue()); |
| if (targetTriple.isKnownWindowsMSVCEnvironment()) { |
| // Dwarf debugging files will be generated by default, unless "CodeView" |
| // is set explicitly. Windows/MSVC should use CodeView instead. |
| llvmModule.addModuleFlag(llvm::Module::Warning, "CodeView", 1); |
| } |
| } |
| } |
| |
| /// Finalize the translation of debug information. |
| void DebugTranslation::finalize() { builder.finalize(); } |
| |
| /// Attempt to extract a filename for the given loc. |
| static FileLineColLoc extractFileLoc(Location loc) { |
| if (auto fileLoc = loc.dyn_cast<FileLineColLoc>()) |
| return fileLoc; |
| if (auto nameLoc = loc.dyn_cast<NameLoc>()) |
| return extractFileLoc(nameLoc.getChildLoc()); |
| if (auto opaqueLoc = loc.dyn_cast<OpaqueLoc>()) |
| return extractFileLoc(opaqueLoc.getFallbackLocation()); |
| return FileLineColLoc(); |
| } |
| |
| /// Translate the debug information for the given function. |
| void DebugTranslation::translate(LLVMFuncOp func, llvm::Function &llvmFunc) { |
| // If the function doesn't have location information, there is nothing to |
| // translate. |
| if (!compileUnit || !func.walk(interruptIfValidLocation).wasInterrupted()) |
| return; |
| |
| // If we are to create debug info for the function, we need to ensure that all |
| // inlinable calls in it are with debug info, otherwise the LLVM verifier will |
| // complain. For now, be more restricted and treat all calls as inlinable. |
| const bool hasCallWithoutDebugInfo = |
| func.walk([](LLVM::CallOp call) { |
| return call.getLoc().isa<UnknownLoc>() ? WalkResult::interrupt() |
| : WalkResult::advance(); |
| }) |
| .wasInterrupted(); |
| if (hasCallWithoutDebugInfo) |
| return; |
| |
| FileLineColLoc fileLoc = extractFileLoc(func.getLoc()); |
| auto *file = |
| translateFile(fileLoc ? fileLoc.getFilename().strref() : "<unknown>"); |
| unsigned line = fileLoc ? fileLoc.getLine() : 0; |
| |
| // TODO: This is the bare essentials for now. We will likely end |
| // up with wrapper metadata around LLVMs metadata in the future, so this |
| // doesn't need to be smart until then. |
| llvm::DISubroutineType *type = |
| builder.createSubroutineType(builder.getOrCreateTypeArray(llvm::None)); |
| llvm::DISubprogram::DISPFlags spFlags = llvm::DISubprogram::SPFlagDefinition | |
| llvm::DISubprogram::SPFlagOptimized; |
| llvm::DISubprogram *program = |
| builder.createFunction(compileUnit, func.getName(), func.getName(), file, |
| line, type, line, llvm::DINode::FlagZero, spFlags); |
| llvmFunc.setSubprogram(program); |
| builder.finalizeSubprogram(program); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Locations |
| //===----------------------------------------------------------------------===// |
| |
| /// Translate the given location to an llvm debug location. |
| const llvm::DILocation * |
| DebugTranslation::translateLoc(Location loc, llvm::DILocalScope *scope) { |
| if (!compileUnit) |
| return nullptr; |
| return translateLoc(loc, scope, /*inlinedAt=*/nullptr); |
| } |
| |
| /// Translate the given location to an llvm DebugLoc. |
| const llvm::DILocation * |
| DebugTranslation::translateLoc(Location loc, llvm::DILocalScope *scope, |
| const llvm::DILocation *inlinedAt) { |
| // LLVM doesn't have a representation for unknown. |
| if (!scope || loc.isa<UnknownLoc>()) |
| return nullptr; |
| |
| // Check for a cached instance. |
| auto existingIt = locationToLoc.find(std::make_pair(loc, scope)); |
| if (existingIt != locationToLoc.end()) |
| return existingIt->second; |
| |
| const llvm::DILocation *llvmLoc = nullptr; |
| if (auto callLoc = loc.dyn_cast<CallSiteLoc>()) { |
| // For callsites, the caller is fed as the inlinedAt for the callee. |
| const auto *callerLoc = translateLoc(callLoc.getCaller(), scope, inlinedAt); |
| llvmLoc = translateLoc(callLoc.getCallee(), scope, callerLoc); |
| |
| } else if (auto fileLoc = loc.dyn_cast<FileLineColLoc>()) { |
| auto *file = translateFile(fileLoc.getFilename()); |
| auto *fileScope = builder.createLexicalBlockFile(scope, file); |
| llvmLoc = llvm::DILocation::get(llvmCtx, fileLoc.getLine(), |
| fileLoc.getColumn(), fileScope, |
| const_cast<llvm::DILocation *>(inlinedAt)); |
| |
| } else if (auto fusedLoc = loc.dyn_cast<FusedLoc>()) { |
| ArrayRef<Location> locations = fusedLoc.getLocations(); |
| |
| // For fused locations, merge each of the nodes. |
| llvmLoc = translateLoc(locations.front(), scope, inlinedAt); |
| for (Location locIt : locations.drop_front()) { |
| llvmLoc = llvm::DILocation::getMergedLocation( |
| llvmLoc, translateLoc(locIt, scope, inlinedAt)); |
| } |
| |
| } else if (auto nameLoc = loc.dyn_cast<NameLoc>()) { |
| llvmLoc = translateLoc(loc.cast<NameLoc>().getChildLoc(), scope, inlinedAt); |
| |
| } else if (auto opaqueLoc = loc.dyn_cast<OpaqueLoc>()) { |
| llvmLoc = translateLoc(loc.cast<OpaqueLoc>().getFallbackLocation(), scope, |
| inlinedAt); |
| } else { |
| llvm_unreachable("unknown location kind"); |
| } |
| |
| locationToLoc.try_emplace(std::make_pair(loc, scope), llvmLoc); |
| return llvmLoc; |
| } |
| |
| /// Create an llvm debug file for the given file path. |
| llvm::DIFile *DebugTranslation::translateFile(StringRef fileName) { |
| auto *&file = fileMap[fileName]; |
| if (file) |
| return file; |
| |
| // Make sure the current working directory is up-to-date. |
| if (currentWorkingDir.empty()) |
| llvm::sys::fs::current_path(currentWorkingDir); |
| |
| StringRef directory = currentWorkingDir; |
| SmallString<128> dirBuf; |
| SmallString<128> fileBuf; |
| if (llvm::sys::path::is_absolute(fileName)) { |
| // Strip the common prefix (if it is more than just "/") from current |
| // directory and FileName for a more space-efficient encoding. |
| auto fileIt = llvm::sys::path::begin(fileName); |
| auto fileE = llvm::sys::path::end(fileName); |
| auto curDirIt = llvm::sys::path::begin(directory); |
| auto curDirE = llvm::sys::path::end(directory); |
| for (; curDirIt != curDirE && *curDirIt == *fileIt; ++curDirIt, ++fileIt) |
| llvm::sys::path::append(dirBuf, *curDirIt); |
| if (std::distance(llvm::sys::path::begin(directory), curDirIt) == 1) { |
| // Don't strip the common prefix if it is only the root "/" since that |
| // would make LLVM diagnostic locations confusing. |
| directory = StringRef(); |
| } else { |
| for (; fileIt != fileE; ++fileIt) |
| llvm::sys::path::append(fileBuf, *fileIt); |
| directory = dirBuf; |
| fileName = fileBuf; |
| } |
| } |
| return (file = builder.createFile(fileName, directory)); |
| } |