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/ADT/Statistic.h" 18 #include "llvm/Analysis/Passes.h" 19 #include "llvm/IR/DebugInfo.h" 20 #include "llvm/InitializePasses.h" 21 #include "llvm/Pass.h" 22 #include "llvm/Support/ErrorHandling.h" 23 #include "llvm/Support/raw_ostream.h" 24 using namespace llvm; 25 26 namespace { 27 class ModuleDebugInfoPrinter : public ModulePass { 28 DebugInfoFinder Finder; 29 public: 30 static char ID; // Pass identification, replacement for typeid 31 ModuleDebugInfoPrinter() : ModulePass(ID) { 32 initializeModuleDebugInfoPrinterPass(*PassRegistry::getPassRegistry()); 33 } 34 35 bool runOnModule(Module &M) override; 36 37 void getAnalysisUsage(AnalysisUsage &AU) const override { 38 AU.setPreservesAll(); 39 } 40 void print(raw_ostream &O, const Module *M) const override; 41 }; 42 } 43 44 char ModuleDebugInfoPrinter::ID = 0; 45 INITIALIZE_PASS(ModuleDebugInfoPrinter, "module-debuginfo", 46 "Decodes module-level debug info", false, true) 47 48 ModulePass *llvm::createModuleDebugInfoPrinterPass() { 49 return new ModuleDebugInfoPrinter(); 50 } 51 52 bool ModuleDebugInfoPrinter::runOnModule(Module &M) { 53 Finder.processModule(M); 54 return false; 55 } 56 57 static void printFile(raw_ostream &O, StringRef Filename, StringRef Directory, 58 unsigned Line = 0) { 59 if (Filename.empty()) 60 return; 61 62 O << " from "; 63 if (!Directory.empty()) 64 O << Directory << "/"; 65 O << Filename; 66 if (Line) 67 O << ":" << Line; 68 } 69 70 void ModuleDebugInfoPrinter::print(raw_ostream &O, const Module *M) const { 71 // Printing the nodes directly isn't particularly helpful (since they 72 // reference other nodes that won't be printed, particularly for the 73 // filenames), so just print a few useful things. 74 for (DICompileUnit *CU : Finder.compile_units()) { 75 O << "Compile unit: "; 76 auto Lang = dwarf::LanguageString(CU->getSourceLanguage()); 77 if (!Lang.empty()) 78 O << Lang; 79 else 80 O << "unknown-language(" << CU->getSourceLanguage() << ")"; 81 printFile(O, CU->getFilename(), CU->getDirectory()); 82 O << '\n'; 83 } 84 85 for (DISubprogram *S : Finder.subprograms()) { 86 O << "Subprogram: " << S->getName(); 87 printFile(O, S->getFilename(), S->getDirectory(), S->getLine()); 88 if (!S->getLinkageName().empty()) 89 O << " ('" << S->getLinkageName() << "')"; 90 O << '\n'; 91 } 92 93 for (auto GVU : Finder.global_variables()) { 94 const auto *GV = GVU->getVariable(); 95 O << "Global variable: " << GV->getName(); 96 printFile(O, GV->getFilename(), GV->getDirectory(), GV->getLine()); 97 if (!GV->getLinkageName().empty()) 98 O << " ('" << GV->getLinkageName() << "')"; 99 O << '\n'; 100 } 101 102 for (const DIType *T : Finder.types()) { 103 O << "Type:"; 104 if (!T->getName().empty()) 105 O << ' ' << T->getName(); 106 printFile(O, T->getFilename(), T->getDirectory(), T->getLine()); 107 if (auto *BT = dyn_cast<DIBasicType>(T)) { 108 O << " "; 109 auto Encoding = dwarf::AttributeEncodingString(BT->getEncoding()); 110 if (!Encoding.empty()) 111 O << Encoding; 112 else 113 O << "unknown-encoding(" << BT->getEncoding() << ')'; 114 } else { 115 O << ' '; 116 auto Tag = dwarf::TagString(T->getTag()); 117 if (!Tag.empty()) 118 O << Tag; 119 else 120 O << "unknown-tag(" << T->getTag() << ")"; 121 } 122 if (auto *CT = dyn_cast<DICompositeType>(T)) { 123 if (auto *S = CT->getRawIdentifier()) 124 O << " (identifier: '" << S->getString() << "')"; 125 } 126 O << '\n'; 127 } 128 } 129