1 //===-- ModuleDebugInfoPrinter.cpp - Prints module debug info metadata ----===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This pass decodes the debug info metadata in a module and prints in a 10 // (sufficiently-prepared-) human-readable form. 11 // 12 // For example, run this pass from opt along with the -analyze option, and 13 // it'll print to standard output. 14 // 15 //===----------------------------------------------------------------------===// 16 17 #include "llvm/Analysis/ModuleDebugInfoPrinter.h" 18 #include "llvm/Analysis/Passes.h" 19 #include "llvm/BinaryFormat/Dwarf.h" 20 #include "llvm/IR/DebugInfo.h" 21 #include "llvm/IR/PassManager.h" 22 #include "llvm/InitializePasses.h" 23 #include "llvm/Pass.h" 24 #include "llvm/Support/ErrorHandling.h" 25 #include "llvm/Support/raw_ostream.h" 26 using namespace llvm; 27 28 static void printFile(raw_ostream &O, StringRef Filename, StringRef Directory, 29 unsigned Line = 0) { 30 if (Filename.empty()) 31 return; 32 33 O << " from "; 34 if (!Directory.empty()) 35 O << Directory << "/"; 36 O << Filename; 37 if (Line) 38 O << ":" << Line; 39 } 40 41 static void printModuleDebugInfo(raw_ostream &O, const Module *M, 42 const DebugInfoFinder &Finder) { 43 // Printing the nodes directly isn't particularly helpful (since they 44 // reference other nodes that won't be printed, particularly for the 45 // filenames), so just print a few useful things. 46 for (DICompileUnit *CU : Finder.compile_units()) { 47 O << "Compile unit: "; 48 auto Lang = dwarf::LanguageString(CU->getSourceLanguage()); 49 if (!Lang.empty()) 50 O << Lang; 51 else 52 O << "unknown-language(" << CU->getSourceLanguage() << ")"; 53 printFile(O, CU->getFilename(), CU->getDirectory()); 54 O << '\n'; 55 } 56 57 for (DISubprogram *S : Finder.subprograms()) { 58 O << "Subprogram: " << S->getName(); 59 printFile(O, S->getFilename(), S->getDirectory(), S->getLine()); 60 if (!S->getLinkageName().empty()) 61 O << " ('" << S->getLinkageName() << "')"; 62 O << '\n'; 63 } 64 65 for (auto *GVU : Finder.global_variables()) { 66 const auto *GV = GVU->getVariable(); 67 O << "Global variable: " << GV->getName(); 68 printFile(O, GV->getFilename(), GV->getDirectory(), GV->getLine()); 69 if (!GV->getLinkageName().empty()) 70 O << " ('" << GV->getLinkageName() << "')"; 71 O << '\n'; 72 } 73 74 for (const DIType *T : Finder.types()) { 75 O << "Type:"; 76 if (!T->getName().empty()) 77 O << ' ' << T->getName(); 78 printFile(O, T->getFilename(), T->getDirectory(), T->getLine()); 79 if (auto *BT = dyn_cast<DIBasicType>(T)) { 80 O << " "; 81 auto Encoding = dwarf::AttributeEncodingString(BT->getEncoding()); 82 if (!Encoding.empty()) 83 O << Encoding; 84 else 85 O << "unknown-encoding(" << BT->getEncoding() << ')'; 86 } else { 87 O << ' '; 88 auto Tag = dwarf::TagString(T->getTag()); 89 if (!Tag.empty()) 90 O << Tag; 91 else 92 O << "unknown-tag(" << T->getTag() << ")"; 93 } 94 if (auto *CT = dyn_cast<DICompositeType>(T)) { 95 if (auto *S = CT->getRawIdentifier()) 96 O << " (identifier: '" << S->getString() << "')"; 97 } 98 O << '\n'; 99 } 100 } 101 102 ModuleDebugInfoPrinterPass::ModuleDebugInfoPrinterPass(raw_ostream &OS) 103 : OS(OS) {} 104 105 PreservedAnalyses ModuleDebugInfoPrinterPass::run(Module &M, 106 ModuleAnalysisManager &AM) { 107 Finder.processModule(M); 108 printModuleDebugInfo(OS, &M, Finder); 109 return PreservedAnalyses::all(); 110 } 111