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/ADT/Statistic.h" 19 #include "llvm/Analysis/Passes.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 namespace { 29 class ModuleDebugInfoLegacyPrinter : public ModulePass { 30 DebugInfoFinder Finder; 31 32 public: 33 static char ID; // Pass identification, replacement for typeid 34 ModuleDebugInfoLegacyPrinter() : ModulePass(ID) { 35 initializeModuleDebugInfoLegacyPrinterPass( 36 *PassRegistry::getPassRegistry()); 37 } 38 39 bool runOnModule(Module &M) override; 40 41 void getAnalysisUsage(AnalysisUsage &AU) const override { 42 AU.setPreservesAll(); 43 } 44 void print(raw_ostream &O, const Module *M) const override; 45 }; 46 } 47 48 char ModuleDebugInfoLegacyPrinter::ID = 0; 49 INITIALIZE_PASS(ModuleDebugInfoLegacyPrinter, "module-debuginfo", 50 "Decodes module-level debug info", false, true) 51 52 ModulePass *llvm::createModuleDebugInfoPrinterPass() { 53 return new ModuleDebugInfoLegacyPrinter(); 54 } 55 56 bool ModuleDebugInfoLegacyPrinter::runOnModule(Module &M) { 57 Finder.processModule(M); 58 return false; 59 } 60 61 static void printFile(raw_ostream &O, StringRef Filename, StringRef Directory, 62 unsigned Line = 0) { 63 if (Filename.empty()) 64 return; 65 66 O << " from "; 67 if (!Directory.empty()) 68 O << Directory << "/"; 69 O << Filename; 70 if (Line) 71 O << ":" << Line; 72 } 73 74 static void printModuleDebugInfo(raw_ostream &O, const Module *M, 75 const DebugInfoFinder &Finder) { 76 // Printing the nodes directly isn't particularly helpful (since they 77 // reference other nodes that won't be printed, particularly for the 78 // filenames), so just print a few useful things. 79 for (DICompileUnit *CU : Finder.compile_units()) { 80 O << "Compile unit: "; 81 auto Lang = dwarf::LanguageString(CU->getSourceLanguage()); 82 if (!Lang.empty()) 83 O << Lang; 84 else 85 O << "unknown-language(" << CU->getSourceLanguage() << ")"; 86 printFile(O, CU->getFilename(), CU->getDirectory()); 87 O << '\n'; 88 } 89 90 for (DISubprogram *S : Finder.subprograms()) { 91 O << "Subprogram: " << S->getName(); 92 printFile(O, S->getFilename(), S->getDirectory(), S->getLine()); 93 if (!S->getLinkageName().empty()) 94 O << " ('" << S->getLinkageName() << "')"; 95 O << '\n'; 96 } 97 98 for (auto GVU : Finder.global_variables()) { 99 const auto *GV = GVU->getVariable(); 100 O << "Global variable: " << GV->getName(); 101 printFile(O, GV->getFilename(), GV->getDirectory(), GV->getLine()); 102 if (!GV->getLinkageName().empty()) 103 O << " ('" << GV->getLinkageName() << "')"; 104 O << '\n'; 105 } 106 107 for (const DIType *T : Finder.types()) { 108 O << "Type:"; 109 if (!T->getName().empty()) 110 O << ' ' << T->getName(); 111 printFile(O, T->getFilename(), T->getDirectory(), T->getLine()); 112 if (auto *BT = dyn_cast<DIBasicType>(T)) { 113 O << " "; 114 auto Encoding = dwarf::AttributeEncodingString(BT->getEncoding()); 115 if (!Encoding.empty()) 116 O << Encoding; 117 else 118 O << "unknown-encoding(" << BT->getEncoding() << ')'; 119 } else { 120 O << ' '; 121 auto Tag = dwarf::TagString(T->getTag()); 122 if (!Tag.empty()) 123 O << Tag; 124 else 125 O << "unknown-tag(" << T->getTag() << ")"; 126 } 127 if (auto *CT = dyn_cast<DICompositeType>(T)) { 128 if (auto *S = CT->getRawIdentifier()) 129 O << " (identifier: '" << S->getString() << "')"; 130 } 131 O << '\n'; 132 } 133 } 134 135 void ModuleDebugInfoLegacyPrinter::print(raw_ostream &O, 136 const Module *M) const { 137 printModuleDebugInfo(O, M, Finder); 138 } 139 140 ModuleDebugInfoPrinterPass::ModuleDebugInfoPrinterPass(raw_ostream &OS) 141 : OS(OS) {} 142 143 PreservedAnalyses ModuleDebugInfoPrinterPass::run(Module &M, 144 ModuleAnalysisManager &AM) { 145 Finder.processModule(M); 146 printModuleDebugInfo(OS, &M, Finder); 147 return PreservedAnalyses::all(); 148 } 149