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/Pass.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/raw_ostream.h"
23 using namespace llvm;
24
25 namespace {
26 class ModuleDebugInfoPrinter : public ModulePass {
27 DebugInfoFinder Finder;
28 public:
29 static char ID; // Pass identification, replacement for typeid
ModuleDebugInfoPrinter()30 ModuleDebugInfoPrinter() : ModulePass(ID) {
31 initializeModuleDebugInfoPrinterPass(*PassRegistry::getPassRegistry());
32 }
33
34 bool runOnModule(Module &M) override;
35
getAnalysisUsage(AnalysisUsage & AU) const36 void getAnalysisUsage(AnalysisUsage &AU) const override {
37 AU.setPreservesAll();
38 }
39 void print(raw_ostream &O, const Module *M) const override;
40 };
41 }
42
43 char ModuleDebugInfoPrinter::ID = 0;
44 INITIALIZE_PASS(ModuleDebugInfoPrinter, "module-debuginfo",
45 "Decodes module-level debug info", false, true)
46
createModuleDebugInfoPrinterPass()47 ModulePass *llvm::createModuleDebugInfoPrinterPass() {
48 return new ModuleDebugInfoPrinter();
49 }
50
runOnModule(Module & M)51 bool ModuleDebugInfoPrinter::runOnModule(Module &M) {
52 Finder.processModule(M);
53 return false;
54 }
55
printFile(raw_ostream & O,StringRef Filename,StringRef Directory,unsigned Line=0)56 static void printFile(raw_ostream &O, StringRef Filename, StringRef Directory,
57 unsigned Line = 0) {
58 if (Filename.empty())
59 return;
60
61 O << " from ";
62 if (!Directory.empty())
63 O << Directory << "/";
64 O << Filename;
65 if (Line)
66 O << ":" << Line;
67 }
68
print(raw_ostream & O,const Module * M) const69 void ModuleDebugInfoPrinter::print(raw_ostream &O, const Module *M) const {
70 // Printing the nodes directly isn't particularly helpful (since they
71 // reference other nodes that won't be printed, particularly for the
72 // filenames), so just print a few useful things.
73 for (DICompileUnit *CU : Finder.compile_units()) {
74 O << "Compile unit: ";
75 auto Lang = dwarf::LanguageString(CU->getSourceLanguage());
76 if (!Lang.empty())
77 O << Lang;
78 else
79 O << "unknown-language(" << CU->getSourceLanguage() << ")";
80 printFile(O, CU->getFilename(), CU->getDirectory());
81 O << '\n';
82 }
83
84 for (DISubprogram *S : Finder.subprograms()) {
85 O << "Subprogram: " << S->getName();
86 printFile(O, S->getFilename(), S->getDirectory(), S->getLine());
87 if (!S->getLinkageName().empty())
88 O << " ('" << S->getLinkageName() << "')";
89 O << '\n';
90 }
91
92 for (auto GVU : Finder.global_variables()) {
93 const auto *GV = GVU->getVariable();
94 O << "Global variable: " << GV->getName();
95 printFile(O, GV->getFilename(), GV->getDirectory(), GV->getLine());
96 if (!GV->getLinkageName().empty())
97 O << " ('" << GV->getLinkageName() << "')";
98 O << '\n';
99 }
100
101 for (const DIType *T : Finder.types()) {
102 O << "Type:";
103 if (!T->getName().empty())
104 O << ' ' << T->getName();
105 printFile(O, T->getFilename(), T->getDirectory(), T->getLine());
106 if (auto *BT = dyn_cast<DIBasicType>(T)) {
107 O << " ";
108 auto Encoding = dwarf::AttributeEncodingString(BT->getEncoding());
109 if (!Encoding.empty())
110 O << Encoding;
111 else
112 O << "unknown-encoding(" << BT->getEncoding() << ')';
113 } else {
114 O << ' ';
115 auto Tag = dwarf::TagString(T->getTag());
116 if (!Tag.empty())
117 O << Tag;
118 else
119 O << "unknown-tag(" << T->getTag() << ")";
120 }
121 if (auto *CT = dyn_cast<DICompositeType>(T)) {
122 if (auto *S = CT->getRawIdentifier())
123 O << " (identifier: '" << S->getString() << "')";
124 }
125 O << '\n';
126 }
127 }
128