1//===--- DebugInfo.cpp - Debug Information Helper Classes -----------------===//
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 file implements the helper classes used to build and interpret debug
11// information in LLVM IR form.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/IR/DebugInfo.h"
16#include "LLVMContextImpl.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallPtrSet.h"
19#include "llvm/ADT/SmallString.h"
20#include "llvm/Analysis/ValueTracking.h"
21#include "llvm/IR/Constants.h"
22#include "llvm/IR/DIBuilder.h"
23#include "llvm/IR/DerivedTypes.h"
24#include "llvm/IR/Instructions.h"
25#include "llvm/IR/IntrinsicInst.h"
26#include "llvm/IR/Intrinsics.h"
27#include "llvm/IR/GVMaterializer.h"
28#include "llvm/IR/Module.h"
29#include "llvm/IR/ValueHandle.h"
30#include "llvm/Support/Debug.h"
31#include "llvm/Support/Dwarf.h"
32#include "llvm/Support/raw_ostream.h"
33using namespace llvm;
34using namespace llvm::dwarf;
35
36DISubprogram *llvm::getDISubprogram(const MDNode *Scope) {
37  if (auto *LocalScope = dyn_cast_or_null<DILocalScope>(Scope))
38    return LocalScope->getSubprogram();
39  return nullptr;
40}
41
42DISubprogram *llvm::getDISubprogram(const Function *F) {
43  // We look for the first instr that has a debug annotation leading back to F.
44  for (auto &BB : *F) {
45    auto Inst = std::find_if(BB.begin(), BB.end(), [](const Instruction &Inst) {
46      return Inst.getDebugLoc();
47    });
48    if (Inst == BB.end())
49      continue;
50    DebugLoc DLoc = Inst->getDebugLoc();
51    const MDNode *Scope = DLoc.getInlinedAtScope();
52    auto *Subprogram = getDISubprogram(Scope);
53    return Subprogram->describes(F) ? Subprogram : nullptr;
54  }
55
56  return nullptr;
57}
58
59DITypeIdentifierMap
60llvm::generateDITypeIdentifierMap(const NamedMDNode *CU_Nodes) {
61  DITypeIdentifierMap Map;
62  for (unsigned CUi = 0, CUe = CU_Nodes->getNumOperands(); CUi != CUe; ++CUi) {
63    auto *CU = cast<DICompileUnit>(CU_Nodes->getOperand(CUi));
64    DINodeArray Retain = CU->getRetainedTypes();
65    for (unsigned Ti = 0, Te = Retain.size(); Ti != Te; ++Ti) {
66      if (!isa<DICompositeType>(Retain[Ti]))
67        continue;
68      auto *Ty = cast<DICompositeType>(Retain[Ti]);
69      if (MDString *TypeId = Ty->getRawIdentifier()) {
70        // Definition has priority over declaration.
71        // Try to insert (TypeId, Ty) to Map.
72        std::pair<DITypeIdentifierMap::iterator, bool> P =
73            Map.insert(std::make_pair(TypeId, Ty));
74        // If TypeId already exists in Map and this is a definition, replace
75        // whatever we had (declaration or definition) with the definition.
76        if (!P.second && !Ty->isForwardDecl())
77          P.first->second = Ty;
78      }
79    }
80  }
81  return Map;
82}
83
84//===----------------------------------------------------------------------===//
85// DebugInfoFinder implementations.
86//===----------------------------------------------------------------------===//
87
88void DebugInfoFinder::reset() {
89  CUs.clear();
90  SPs.clear();
91  GVs.clear();
92  TYs.clear();
93  Scopes.clear();
94  NodesSeen.clear();
95  TypeIdentifierMap.clear();
96  TypeMapInitialized = false;
97}
98
99void DebugInfoFinder::InitializeTypeMap(const Module &M) {
100  if (!TypeMapInitialized)
101    if (NamedMDNode *CU_Nodes = M.getNamedMetadata("llvm.dbg.cu")) {
102      TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
103      TypeMapInitialized = true;
104    }
105}
106
107void DebugInfoFinder::processModule(const Module &M) {
108  InitializeTypeMap(M);
109  if (NamedMDNode *CU_Nodes = M.getNamedMetadata("llvm.dbg.cu")) {
110    for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
111      auto *CU = cast<DICompileUnit>(CU_Nodes->getOperand(i));
112      addCompileUnit(CU);
113      for (auto *DIG : CU->getGlobalVariables()) {
114        if (addGlobalVariable(DIG)) {
115          processScope(DIG->getScope());
116          processType(DIG->getType().resolve(TypeIdentifierMap));
117        }
118      }
119      for (auto *SP : CU->getSubprograms())
120        processSubprogram(SP);
121      for (auto *ET : CU->getEnumTypes())
122        processType(ET);
123      for (auto *RT : CU->getRetainedTypes())
124        processType(RT);
125      for (auto *Import : CU->getImportedEntities()) {
126        auto *Entity = Import->getEntity().resolve(TypeIdentifierMap);
127        if (auto *T = dyn_cast<DIType>(Entity))
128          processType(T);
129        else if (auto *SP = dyn_cast<DISubprogram>(Entity))
130          processSubprogram(SP);
131        else if (auto *NS = dyn_cast<DINamespace>(Entity))
132          processScope(NS->getScope());
133        else if (auto *M = dyn_cast<DIModule>(Entity))
134          processScope(M->getScope());
135      }
136    }
137  }
138}
139
140void DebugInfoFinder::processLocation(const Module &M, const DILocation *Loc) {
141  if (!Loc)
142    return;
143  InitializeTypeMap(M);
144  processScope(Loc->getScope());
145  processLocation(M, Loc->getInlinedAt());
146}
147
148void DebugInfoFinder::processType(DIType *DT) {
149  if (!addType(DT))
150    return;
151  processScope(DT->getScope().resolve(TypeIdentifierMap));
152  if (auto *ST = dyn_cast<DISubroutineType>(DT)) {
153    for (DITypeRef Ref : ST->getTypeArray())
154      processType(Ref.resolve(TypeIdentifierMap));
155    return;
156  }
157  if (auto *DCT = dyn_cast<DICompositeType>(DT)) {
158    processType(DCT->getBaseType().resolve(TypeIdentifierMap));
159    for (Metadata *D : DCT->getElements()) {
160      if (auto *T = dyn_cast<DIType>(D))
161        processType(T);
162      else if (auto *SP = dyn_cast<DISubprogram>(D))
163        processSubprogram(SP);
164    }
165    return;
166  }
167  if (auto *DDT = dyn_cast<DIDerivedType>(DT)) {
168    processType(DDT->getBaseType().resolve(TypeIdentifierMap));
169  }
170}
171
172void DebugInfoFinder::processScope(DIScope *Scope) {
173  if (!Scope)
174    return;
175  if (auto *Ty = dyn_cast<DIType>(Scope)) {
176    processType(Ty);
177    return;
178  }
179  if (auto *CU = dyn_cast<DICompileUnit>(Scope)) {
180    addCompileUnit(CU);
181    return;
182  }
183  if (auto *SP = dyn_cast<DISubprogram>(Scope)) {
184    processSubprogram(SP);
185    return;
186  }
187  if (!addScope(Scope))
188    return;
189  if (auto *LB = dyn_cast<DILexicalBlockBase>(Scope)) {
190    processScope(LB->getScope());
191  } else if (auto *NS = dyn_cast<DINamespace>(Scope)) {
192    processScope(NS->getScope());
193  } else if (auto *M = dyn_cast<DIModule>(Scope)) {
194    processScope(M->getScope());
195  }
196}
197
198void DebugInfoFinder::processSubprogram(DISubprogram *SP) {
199  if (!addSubprogram(SP))
200    return;
201  processScope(SP->getScope().resolve(TypeIdentifierMap));
202  processType(SP->getType());
203  for (auto *Element : SP->getTemplateParams()) {
204    if (auto *TType = dyn_cast<DITemplateTypeParameter>(Element)) {
205      processType(TType->getType().resolve(TypeIdentifierMap));
206    } else if (auto *TVal = dyn_cast<DITemplateValueParameter>(Element)) {
207      processType(TVal->getType().resolve(TypeIdentifierMap));
208    }
209  }
210}
211
212void DebugInfoFinder::processDeclare(const Module &M,
213                                     const DbgDeclareInst *DDI) {
214  auto *N = dyn_cast<MDNode>(DDI->getVariable());
215  if (!N)
216    return;
217  InitializeTypeMap(M);
218
219  auto *DV = dyn_cast<DILocalVariable>(N);
220  if (!DV)
221    return;
222
223  if (!NodesSeen.insert(DV).second)
224    return;
225  processScope(DV->getScope());
226  processType(DV->getType().resolve(TypeIdentifierMap));
227}
228
229void DebugInfoFinder::processValue(const Module &M, const DbgValueInst *DVI) {
230  auto *N = dyn_cast<MDNode>(DVI->getVariable());
231  if (!N)
232    return;
233  InitializeTypeMap(M);
234
235  auto *DV = dyn_cast<DILocalVariable>(N);
236  if (!DV)
237    return;
238
239  if (!NodesSeen.insert(DV).second)
240    return;
241  processScope(DV->getScope());
242  processType(DV->getType().resolve(TypeIdentifierMap));
243}
244
245bool DebugInfoFinder::addType(DIType *DT) {
246  if (!DT)
247    return false;
248
249  if (!NodesSeen.insert(DT).second)
250    return false;
251
252  TYs.push_back(const_cast<DIType *>(DT));
253  return true;
254}
255
256bool DebugInfoFinder::addCompileUnit(DICompileUnit *CU) {
257  if (!CU)
258    return false;
259  if (!NodesSeen.insert(CU).second)
260    return false;
261
262  CUs.push_back(CU);
263  return true;
264}
265
266bool DebugInfoFinder::addGlobalVariable(DIGlobalVariable *DIG) {
267  if (!DIG)
268    return false;
269
270  if (!NodesSeen.insert(DIG).second)
271    return false;
272
273  GVs.push_back(DIG);
274  return true;
275}
276
277bool DebugInfoFinder::addSubprogram(DISubprogram *SP) {
278  if (!SP)
279    return false;
280
281  if (!NodesSeen.insert(SP).second)
282    return false;
283
284  SPs.push_back(SP);
285  return true;
286}
287
288bool DebugInfoFinder::addScope(DIScope *Scope) {
289  if (!Scope)
290    return false;
291  // FIXME: Ocaml binding generates a scope with no content, we treat it
292  // as null for now.
293  if (Scope->getNumOperands() == 0)
294    return false;
295  if (!NodesSeen.insert(Scope).second)
296    return false;
297  Scopes.push_back(Scope);
298  return true;
299}
300
301bool llvm::stripDebugInfo(Function &F) {
302  bool Changed = false;
303  if (F.getSubprogram()) {
304    Changed = true;
305    F.setSubprogram(nullptr);
306  }
307  for (BasicBlock &BB : F) {
308    for (Instruction &I : BB) {
309      if (I.getDebugLoc()) {
310        Changed = true;
311        I.setDebugLoc(DebugLoc());
312      }
313    }
314  }
315  return Changed;
316}
317
318bool llvm::StripDebugInfo(Module &M) {
319  bool Changed = false;
320
321  // Remove all of the calls to the debugger intrinsics, and remove them from
322  // the module.
323  if (Function *Declare = M.getFunction("llvm.dbg.declare")) {
324    while (!Declare->use_empty()) {
325      CallInst *CI = cast<CallInst>(Declare->user_back());
326      CI->eraseFromParent();
327    }
328    Declare->eraseFromParent();
329    Changed = true;
330  }
331
332  if (Function *DbgVal = M.getFunction("llvm.dbg.value")) {
333    while (!DbgVal->use_empty()) {
334      CallInst *CI = cast<CallInst>(DbgVal->user_back());
335      CI->eraseFromParent();
336    }
337    DbgVal->eraseFromParent();
338    Changed = true;
339  }
340
341  for (Module::named_metadata_iterator NMI = M.named_metadata_begin(),
342         NME = M.named_metadata_end(); NMI != NME;) {
343    NamedMDNode *NMD = &*NMI;
344    ++NMI;
345    if (NMD->getName().startswith("llvm.dbg.")) {
346      NMD->eraseFromParent();
347      Changed = true;
348    }
349  }
350
351  for (Function &F : M)
352    Changed |= stripDebugInfo(F);
353
354  if (GVMaterializer *Materializer = M.getMaterializer())
355    Materializer->setStripDebugInfo();
356
357  return Changed;
358}
359
360unsigned llvm::getDebugMetadataVersionFromModule(const Module &M) {
361  if (auto *Val = mdconst::dyn_extract_or_null<ConstantInt>(
362          M.getModuleFlag("Debug Info Version")))
363    return Val->getZExtValue();
364  return 0;
365}
366