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
ModuleDebugInfoPrinter()31 ModuleDebugInfoPrinter() : ModulePass(ID) {
32 initializeModuleDebugInfoPrinterPass(*PassRegistry::getPassRegistry());
33 }
34
35 bool runOnModule(Module &M) override;
36
getAnalysisUsage(AnalysisUsage & AU) const37 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
createModuleDebugInfoPrinterPass()48 ModulePass *llvm::createModuleDebugInfoPrinterPass() {
49 return new ModuleDebugInfoPrinter();
50 }
51
runOnModule(Module & M)52 bool ModuleDebugInfoPrinter::runOnModule(Module &M) {
53 Finder.processModule(M);
54 return false;
55 }
56
printFile(raw_ostream & O,StringRef Filename,StringRef Directory,unsigned Line=0)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
print(raw_ostream & O,const Module * M) const70 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