Revert "Revert "Revert "PR20038: DebugInfo: Inlined call sites where the caller has...
[opencl/llvm.git] / lib / CodeGen / LexicalScopes.cpp
1 //===- LexicalScopes.cpp - Collecting lexical scope info ------------------===//
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 LexicalScopes analysis.
11 //
12 // This pass collects lexical scope information and maps machine instructions
13 // to respective lexical scopes.
14 //
15 //===----------------------------------------------------------------------===//
17 #include "llvm/CodeGen/LexicalScopes.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/CodeGen/MachineInstr.h"
20 #include "llvm/IR/DebugInfo.h"
21 #include "llvm/IR/Function.h"
22 #include "llvm/Support/Debug.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/FormattedStream.h"
25 using namespace llvm;
27 #define DEBUG_TYPE "lexicalscopes"
29 /// reset - Reset the instance so that it's prepared for another function.
30 void LexicalScopes::reset() {
31   MF = nullptr;
32   CurrentFnLexicalScope = nullptr;
33   LexicalScopeMap.clear();
34   AbstractScopeMap.clear();
35   InlinedLexicalScopeMap.clear();
36   AbstractScopesList.clear();
37 }
39 /// initialize - Scan machine function and constuct lexical scope nest.
40 void LexicalScopes::initialize(const MachineFunction &Fn) {
41   reset();
42   MF = &Fn;
43   SmallVector<InsnRange, 4> MIRanges;
44   DenseMap<const MachineInstr *, LexicalScope *> MI2ScopeMap;
45   extractLexicalScopes(MIRanges, MI2ScopeMap);
46   if (CurrentFnLexicalScope) {
47     constructScopeNest(CurrentFnLexicalScope);
48     assignInstructionRanges(MIRanges, MI2ScopeMap);
49   }
50 }
52 /// extractLexicalScopes - Extract instruction ranges for each lexical scopes
53 /// for the given machine function.
54 void LexicalScopes::extractLexicalScopes(
55     SmallVectorImpl<InsnRange> &MIRanges,
56     DenseMap<const MachineInstr *, LexicalScope *> &MI2ScopeMap) {
58   // Scan each instruction and create scopes. First build working set of scopes.
59   for (const auto &MBB : *MF) {
60     const MachineInstr *RangeBeginMI = nullptr;
61     const MachineInstr *PrevMI = nullptr;
62     DebugLoc PrevDL;
63     for (const auto &MInsn : MBB) {
64       // Check if instruction has valid location information.
65       const DebugLoc MIDL = MInsn.getDebugLoc();
66       if (MIDL.isUnknown()) {
67         PrevMI = &MInsn;
68         continue;
69       }
71       // If scope has not changed then skip this instruction.
72       if (MIDL == PrevDL) {
73         PrevMI = &MInsn;
74         continue;
75       }
77       // Ignore DBG_VALUE. It does not contribute to any instruction in output.
78       if (MInsn.isDebugValue())
79         continue;
81       if (RangeBeginMI) {
82         // If we have already seen a beginning of an instruction range and
83         // current instruction scope does not match scope of first instruction
84         // in this range then create a new instruction range.
85         InsnRange R(RangeBeginMI, PrevMI);
86         MI2ScopeMap[RangeBeginMI] = getOrCreateLexicalScope(PrevDL);
87         MIRanges.push_back(R);
88       }
90       // This is a beginning of a new instruction range.
91       RangeBeginMI = &MInsn;
93       // Reset previous markers.
94       PrevMI = &MInsn;
95       PrevDL = MIDL;
96     }
98     // Create last instruction range.
99     if (RangeBeginMI && PrevMI && !PrevDL.isUnknown()) {
100       InsnRange R(RangeBeginMI, PrevMI);
101       MIRanges.push_back(R);
102       MI2ScopeMap[RangeBeginMI] = getOrCreateLexicalScope(PrevDL);
103     }
104   }
107 LexicalScope *LexicalScopes::findInlinedScope(DebugLoc DL) {
108   MDNode *Scope = nullptr;
109   MDNode *IA = nullptr;
110   DL.getScopeAndInlinedAt(Scope, IA, MF->getFunction()->getContext());
111   auto I = InlinedLexicalScopeMap.find(std::make_pair(Scope, IA));
112   return I != InlinedLexicalScopeMap.end() ? &I->second : nullptr;
115 /// findLexicalScope - Find lexical scope, either regular or inlined, for the
116 /// given DebugLoc. Return NULL if not found.
117 LexicalScope *LexicalScopes::findLexicalScope(DebugLoc DL) {
118   MDNode *Scope = nullptr;
119   MDNode *IA = nullptr;
120   DL.getScopeAndInlinedAt(Scope, IA, MF->getFunction()->getContext());
121   if (!Scope)
122     return nullptr;
124   // The scope that we were created with could have an extra file - which
125   // isn't what we care about in this case.
126   DIDescriptor D = DIDescriptor(Scope);
127   if (D.isLexicalBlockFile())
128     Scope = DILexicalBlockFile(Scope).getScope();
130   if (IA) {
131     auto I = InlinedLexicalScopeMap.find(std::make_pair(Scope, IA));
132     return I != InlinedLexicalScopeMap.end() ? &I->second : nullptr;
133   }
134   return findLexicalScope(Scope);
137 /// getOrCreateLexicalScope - Find lexical scope for the given DebugLoc. If
138 /// not available then create new lexical scope.
139 LexicalScope *LexicalScopes::getOrCreateLexicalScope(DebugLoc DL) {
140   MDNode *Scope = nullptr;
141   MDNode *InlinedAt = nullptr;
142   DL.getScopeAndInlinedAt(Scope, InlinedAt, MF->getFunction()->getContext());
144   if (InlinedAt) {
145     // Create an abstract scope for inlined function.
146     getOrCreateAbstractScope(Scope);
147     // Create an inlined scope for inlined function.
148     return getOrCreateInlinedScope(Scope, InlinedAt);
149   }
151   return getOrCreateRegularScope(Scope);
154 /// getOrCreateRegularScope - Find or create a regular lexical scope.
155 LexicalScope *LexicalScopes::getOrCreateRegularScope(MDNode *Scope) {
156   DIDescriptor D = DIDescriptor(Scope);
157   if (D.isLexicalBlockFile()) {
158     Scope = DILexicalBlockFile(Scope).getScope();
159     D = DIDescriptor(Scope);
160   }
162   auto I = LexicalScopeMap.find(Scope);
163   if (I != LexicalScopeMap.end())
164     return &I->second;
166   LexicalScope *Parent = nullptr;
167   if (D.isLexicalBlock())
168     Parent = getOrCreateLexicalScope(DebugLoc::getFromDILexicalBlock(Scope));
169   // FIXME: Use forward_as_tuple instead of make_tuple, once MSVC2012
170   // compatibility is no longer required.
171   I = LexicalScopeMap.emplace(std::piecewise_construct, std::make_tuple(Scope),
172                               std::make_tuple(Parent, DIDescriptor(Scope),
173                                               nullptr, false)).first;
175   if (!Parent && DIDescriptor(Scope).isSubprogram() &&
176       DISubprogram(Scope).describes(MF->getFunction()))
177     CurrentFnLexicalScope = &I->second;
179   return &I->second;
182 /// getOrCreateInlinedScope - Find or create an inlined lexical scope.
183 LexicalScope *LexicalScopes::getOrCreateInlinedScope(MDNode *ScopeNode,
184                                                      MDNode *InlinedAt) {
185   std::pair<const MDNode*, const MDNode*> P(ScopeNode, InlinedAt);
186   auto I = InlinedLexicalScopeMap.find(P);
187   if (I != InlinedLexicalScopeMap.end())
188     return &I->second;
190   LexicalScope *Parent;
191   DILexicalBlock Scope(ScopeNode);
192   if (Scope.isSubprogram())
193     Parent = getOrCreateLexicalScope(DebugLoc::getFromDILocation(InlinedAt));
194   else
195     Parent = getOrCreateInlinedScope(Scope.getContext(), InlinedAt);
197   // FIXME: Use forward_as_tuple instead of make_tuple, once MSVC2012
198   // compatibility is no longer required.
199   I = InlinedLexicalScopeMap.emplace(std::piecewise_construct,
200                                      std::make_tuple(P),
201                                      std::make_tuple(Parent, Scope, InlinedAt,
202                                                      false)).first;
203   return &I->second;
206 /// getOrCreateAbstractScope - Find or create an abstract lexical scope.
207 LexicalScope *LexicalScopes::getOrCreateAbstractScope(const MDNode *N) {
208   assert(N && "Invalid Scope encoding!");
210   DIDescriptor Scope(N);
211   if (Scope.isLexicalBlockFile())
212     Scope = DILexicalBlockFile(Scope).getScope();
213   auto I = AbstractScopeMap.find(Scope);
214   if (I != AbstractScopeMap.end())
215     return &I->second;
217   LexicalScope *Parent = nullptr;
218   if (Scope.isLexicalBlock()) {
219     DILexicalBlock DB(Scope);
220     DIDescriptor ParentDesc = DB.getContext();
221     Parent = getOrCreateAbstractScope(ParentDesc);
222   }
223   I = AbstractScopeMap.emplace(std::piecewise_construct,
224                                std::forward_as_tuple(Scope),
225                                std::forward_as_tuple(Parent, Scope,
226                                                      nullptr, true)).first;
227   if (Scope.isSubprogram())
228     AbstractScopesList.push_back(&I->second);
229   return &I->second;
232 /// constructScopeNest
233 void LexicalScopes::constructScopeNest(LexicalScope *Scope) {
234   assert(Scope && "Unable to calculate scope dominance graph!");
235   SmallVector<LexicalScope *, 4> WorkStack;
236   WorkStack.push_back(Scope);
237   unsigned Counter = 0;
238   while (!WorkStack.empty()) {
239     LexicalScope *WS = WorkStack.back();
240     const SmallVectorImpl<LexicalScope *> &Children = WS->getChildren();
241     bool visitedChildren = false;
242     for (SmallVectorImpl<LexicalScope *>::const_iterator SI = Children.begin(),
243                                                          SE = Children.end();
244          SI != SE; ++SI) {
245       LexicalScope *ChildScope = *SI;
246       if (!ChildScope->getDFSOut()) {
247         WorkStack.push_back(ChildScope);
248         visitedChildren = true;
249         ChildScope->setDFSIn(++Counter);
250         break;
251       }
252     }
253     if (!visitedChildren) {
254       WorkStack.pop_back();
255       WS->setDFSOut(++Counter);
256     }
257   }
260 /// assignInstructionRanges - Find ranges of instructions covered by each
261 /// lexical scope.
262 void LexicalScopes::assignInstructionRanges(
263     SmallVectorImpl<InsnRange> &MIRanges,
264     DenseMap<const MachineInstr *, LexicalScope *> &MI2ScopeMap) {
266   LexicalScope *PrevLexicalScope = nullptr;
267   for (SmallVectorImpl<InsnRange>::const_iterator RI = MIRanges.begin(),
268                                                   RE = MIRanges.end();
269        RI != RE; ++RI) {
270     const InsnRange &R = *RI;
271     LexicalScope *S = MI2ScopeMap.lookup(R.first);
272     assert(S && "Lost LexicalScope for a machine instruction!");
273     if (PrevLexicalScope && !PrevLexicalScope->dominates(S))
274       PrevLexicalScope->closeInsnRange(S);
275     S->openInsnRange(R.first);
276     S->extendInsnRange(R.second);
277     PrevLexicalScope = S;
278   }
280   if (PrevLexicalScope)
281     PrevLexicalScope->closeInsnRange();
284 /// getMachineBasicBlocks - Populate given set using machine basic blocks which
285 /// have machine instructions that belong to lexical scope identified by
286 /// DebugLoc.
287 void LexicalScopes::getMachineBasicBlocks(
288     DebugLoc DL, SmallPtrSet<const MachineBasicBlock *, 4> &MBBs) {
289   MBBs.clear();
290   LexicalScope *Scope = getOrCreateLexicalScope(DL);
291   if (!Scope)
292     return;
294   if (Scope == CurrentFnLexicalScope) {
295     for (const auto &MBB : *MF)
296       MBBs.insert(&MBB);
297     return;
298   }
300   SmallVectorImpl<InsnRange> &InsnRanges = Scope->getRanges();
301   for (SmallVectorImpl<InsnRange>::iterator I = InsnRanges.begin(),
302                                             E = InsnRanges.end();
303        I != E; ++I) {
304     InsnRange &R = *I;
305     MBBs.insert(R.first->getParent());
306   }
309 /// dominates - Return true if DebugLoc's lexical scope dominates at least one
310 /// machine instruction's lexical scope in a given machine basic block.
311 bool LexicalScopes::dominates(DebugLoc DL, MachineBasicBlock *MBB) {
312   LexicalScope *Scope = getOrCreateLexicalScope(DL);
313   if (!Scope)
314     return false;
316   // Current function scope covers all basic blocks in the function.
317   if (Scope == CurrentFnLexicalScope && MBB->getParent() == MF)
318     return true;
320   bool Result = false;
321   for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end(); I != E;
322        ++I) {
323     DebugLoc IDL = I->getDebugLoc();
324     if (IDL.isUnknown())
325       continue;
326     if (LexicalScope *IScope = getOrCreateLexicalScope(IDL))
327       if (Scope->dominates(IScope))
328         return true;
329   }
330   return Result;
333 /// dump - Print data structures.
334 void LexicalScope::dump(unsigned Indent) const {
335 #ifndef NDEBUG
336   raw_ostream &err = dbgs();
337   err.indent(Indent);
338   err << "DFSIn: " << DFSIn << " DFSOut: " << DFSOut << "\n";
339   const MDNode *N = Desc;
340   err.indent(Indent);
341   N->dump();
342   if (AbstractScope)
343     err << std::string(Indent, ' ') << "Abstract Scope\n";
345   if (!Children.empty())
346     err << std::string(Indent + 2, ' ') << "Children ...\n";
347   for (unsigned i = 0, e = Children.size(); i != e; ++i)
348     if (Children[i] != this)
349       Children[i]->dump(Indent + 2);
350 #endif