1//===-- ModuleDebugInfoPrinter.cpp - Prints module debug info metadata ----===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This pass decodes the debug info metadata in a module and prints in a
11// (sufficiently-prepared-) human-readable form.
12//
13// For example, run this pass from opt along with the -analyze option, and
14// it'll print to standard output.
15//
16//===----------------------------------------------------------------------===//
17
18#include "llvm/Analysis/Passes.h"
19#include "llvm/ADT/Statistic.h"
20#include "llvm/IR/DebugInfo.h"
21#include "llvm/IR/Function.h"
22#include "llvm/Pass.h"
23#include "llvm/Support/ErrorHandling.h"
24#include "llvm/Support/raw_ostream.h"
25using namespace llvm;
26
27namespace {
28  class ModuleDebugInfoPrinter : public ModulePass {
29    DebugInfoFinder Finder;
30  public:
31    static char ID; // Pass identification, replacement for typeid
32    ModuleDebugInfoPrinter() : ModulePass(ID) {
33      initializeModuleDebugInfoPrinterPass(*PassRegistry::getPassRegistry());
34    }
35
36    bool runOnModule(Module &M) override;
37
38    void getAnalysisUsage(AnalysisUsage &AU) const override {
39      AU.setPreservesAll();
40    }
41    void print(raw_ostream &O, const Module *M) const override;
42  };
43}
44
45char ModuleDebugInfoPrinter::ID = 0;
46INITIALIZE_PASS(ModuleDebugInfoPrinter, "module-debuginfo",
47                "Decodes module-level debug info", false, true)
48
49ModulePass *llvm::createModuleDebugInfoPrinterPass() {
50  return new ModuleDebugInfoPrinter();
51}
52
53bool ModuleDebugInfoPrinter::runOnModule(Module &M) {
54  Finder.processModule(M);
55  return false;
56}
57
58static void printFile(raw_ostream &O, StringRef Filename, StringRef Directory,
59                      unsigned Line = 0) {
60  if (Filename.empty())
61    return;
62
63  O << " from ";
64  if (!Directory.empty())
65    O << Directory << "/";
66  O << Filename;
67  if (Line)
68    O << ":" << Line;
69}
70
71void ModuleDebugInfoPrinter::print(raw_ostream &O, const Module *M) const {
72  // Printing the nodes directly isn't particularly helpful (since they
73  // reference other nodes that won't be printed, particularly for the
74  // filenames), so just print a few useful things.
75  for (DICompileUnit *CU : Finder.compile_units()) {
76    O << "Compile unit: ";
77    if (const char *Lang = dwarf::LanguageString(CU->getSourceLanguage()))
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 (const DIGlobalVariable *GV : Finder.global_variables()) {
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      if (const char *Encoding =
109              dwarf::AttributeEncodingString(BT->getEncoding()))
110        O << Encoding;
111      else
112        O << "unknown-encoding(" << BT->getEncoding() << ')';
113    } else {
114      O << ' ';
115      if (const char *Tag = dwarf::TagString(T->getTag()))
116        O << Tag;
117      else
118        O << "unknown-tag(" << T->getTag() << ")";
119    }
120    if (auto *CT = dyn_cast<DICompositeType>(T)) {
121      if (auto *S = CT->getRawIdentifier())
122        O << " (identifier: '" << S->getString() << "')";
123    }
124    O << '\n';
125  }
126}
127