1 //===-- DebugLoc.cpp - Implement DebugLoc class ---------------------------===//
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 #include "llvm/IR/DebugLoc.h"
11 #include "LLVMContextImpl.h"
12 #include "llvm/ADT/DenseMapInfo.h"
13 #include "llvm/IR/DebugInfo.h"
14 using namespace llvm;
15 
16 //===----------------------------------------------------------------------===//
17 // DebugLoc Implementation
18 //===----------------------------------------------------------------------===//
19 
20 MDNode *DebugLoc::getScope(const LLVMContext &Ctx) const {
21   if (ScopeIdx == 0) return nullptr;
22 
23   if (ScopeIdx > 0) {
24     // Positive ScopeIdx is an index into ScopeRecords, which has no inlined-at
25     // position specified.
26     assert(unsigned(ScopeIdx) <= Ctx.pImpl->ScopeRecords.size() &&
27            "Invalid ScopeIdx!");
28     return Ctx.pImpl->ScopeRecords[ScopeIdx-1].get();
29   }
30 
31   // Otherwise, the index is in the ScopeInlinedAtRecords array.
32   assert(unsigned(-ScopeIdx) <= Ctx.pImpl->ScopeInlinedAtRecords.size() &&
33          "Invalid ScopeIdx");
34   return Ctx.pImpl->ScopeInlinedAtRecords[-ScopeIdx-1].first.get();
35 }
36 
37 MDNode *DebugLoc::getInlinedAt(const LLVMContext &Ctx) const {
38   // Positive ScopeIdx is an index into ScopeRecords, which has no inlined-at
39   // position specified.  Zero is invalid.
40   if (ScopeIdx >= 0) return nullptr;
41 
42   // Otherwise, the index is in the ScopeInlinedAtRecords array.
43   assert(unsigned(-ScopeIdx) <= Ctx.pImpl->ScopeInlinedAtRecords.size() &&
44          "Invalid ScopeIdx");
45   return Ctx.pImpl->ScopeInlinedAtRecords[-ScopeIdx-1].second.get();
46 }
47 
48 /// Return both the Scope and the InlinedAt values.
49 void DebugLoc::getScopeAndInlinedAt(MDNode *&Scope, MDNode *&IA,
50                                     const LLVMContext &Ctx) const {
51   if (ScopeIdx == 0) {
52     Scope = IA = nullptr;
53     return;
54   }
55 
56   if (ScopeIdx > 0) {
57     // Positive ScopeIdx is an index into ScopeRecords, which has no inlined-at
58     // position specified.
59     assert(unsigned(ScopeIdx) <= Ctx.pImpl->ScopeRecords.size() &&
60            "Invalid ScopeIdx!");
61     Scope = Ctx.pImpl->ScopeRecords[ScopeIdx-1].get();
62     IA = nullptr;
63     return;
64   }
65 
66   // Otherwise, the index is in the ScopeInlinedAtRecords array.
67   assert(unsigned(-ScopeIdx) <= Ctx.pImpl->ScopeInlinedAtRecords.size() &&
68          "Invalid ScopeIdx");
69   Scope = Ctx.pImpl->ScopeInlinedAtRecords[-ScopeIdx-1].first.get();
70   IA    = Ctx.pImpl->ScopeInlinedAtRecords[-ScopeIdx-1].second.get();
71 }
72 
73 MDNode *DebugLoc::getScopeNode(const LLVMContext &Ctx) const {
74   if (MDNode *InlinedAt = getInlinedAt(Ctx))
75     return DebugLoc::getFromDILocation(InlinedAt).getScopeNode(Ctx);
76   return getScope(Ctx);
77 }
78 
79 DebugLoc DebugLoc::getFnDebugLoc(const LLVMContext &Ctx) const {
80   const MDNode *Scope = getScopeNode(Ctx);
81   DISubprogram SP = getDISubprogram(Scope);
82   if (SP.isSubprogram())
83     return DebugLoc::get(SP.getScopeLineNumber(), 0, SP);
84 
85   return DebugLoc();
86 }
87 
88 DebugLoc DebugLoc::get(unsigned Line, unsigned Col,
89                        MDNode *Scope, MDNode *InlinedAt) {
90   DebugLoc Result;
91 
92   // If no scope is available, this is an unknown location.
93   if (!Scope) return Result;
94 
95   // Saturate line and col to "unknown".
96   if (Col > 255) Col = 0;
97   if (Line >= (1 << 24)) Line = 0;
98   Result.LineCol = Line | (Col << 24);
99 
100   LLVMContext &Ctx = Scope->getContext();
101 
102   // If there is no inlined-at location, use the ScopeRecords array.
103   if (!InlinedAt)
104     Result.ScopeIdx = Ctx.pImpl->getOrAddScopeRecordIdxEntry(Scope, 0);
105   else
106     Result.ScopeIdx = Ctx.pImpl->getOrAddScopeInlinedAtIdxEntry(Scope,
107                                                                 InlinedAt, 0);
108 
109   return Result;
110 }
111 
112 /// getAsMDNode - This method converts the compressed DebugLoc node into a
113 /// DILocation-compatible MDNode.
114 MDNode *DebugLoc::getAsMDNode(const LLVMContext &Ctx) const {
115   if (isUnknown()) return nullptr;
116 
117   MDNode *Scope, *IA;
118   getScopeAndInlinedAt(Scope, IA, Ctx);
119   assert(Scope && "If scope is null, this should be isUnknown()");
120 
121   LLVMContext &Ctx2 = Scope->getContext();
122   Type *Int32 = Type::getInt32Ty(Ctx2);
123   Value *Elts[] = {
124     ConstantInt::get(Int32, getLine()), ConstantInt::get(Int32, getCol()),
125     Scope, IA
126   };
127   return MDNode::get(Ctx2, Elts);
128 }
129 
130 /// getFromDILocation - Translate the DILocation quad into a DebugLoc.
131 DebugLoc DebugLoc::getFromDILocation(MDNode *N) {
132   DILocation Loc(N);
133   MDNode *Scope = Loc.getScope();
134   if (!Scope) return DebugLoc();
135   return get(Loc.getLineNumber(), Loc.getColumnNumber(), Scope,
136              Loc.getOrigLocation());
137 }
138 
139 /// getFromDILexicalBlock - Translate the DILexicalBlock into a DebugLoc.
140 DebugLoc DebugLoc::getFromDILexicalBlock(MDNode *N) {
141   DILexicalBlock LexBlock(N);
142   MDNode *Scope = LexBlock.getContext();
143   if (!Scope) return DebugLoc();
144   return get(LexBlock.getLineNumber(), LexBlock.getColumnNumber(), Scope,
145              nullptr);
146 }
147 
148 void DebugLoc::dump(const LLVMContext &Ctx) const {
149 #ifndef NDEBUG
150   if (!isUnknown()) {
151     dbgs() << getLine();
152     if (getCol() != 0)
153       dbgs() << ',' << getCol();
154     DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(getInlinedAt(Ctx));
155     if (!InlinedAtDL.isUnknown()) {
156       dbgs() << " @ ";
157       InlinedAtDL.dump(Ctx);
158     } else
159       dbgs() << "\n";
160   }
161 #endif
162 }
163 
164 void DebugLoc::print(const LLVMContext &Ctx, raw_ostream &OS) const {
165   if (!isUnknown()) {
166     // Print source line info.
167     DIScope Scope(getScope(Ctx));
168     assert((!Scope || Scope.isScope()) &&
169            "Scope of a DebugLoc should be null or a DIScope.");
170     if (Scope)
171       OS << Scope.getFilename();
172     else
173       OS << "<unknown>";
174     OS << ':' << getLine();
175     if (getCol() != 0)
176       OS << ':' << getCol();
177     DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(getInlinedAt(Ctx));
178     if (!InlinedAtDL.isUnknown()) {
179       OS << " @[ ";
180       InlinedAtDL.print(Ctx, OS);
181       OS << " ]";
182     }
183   }
184 }
185 
186 //===----------------------------------------------------------------------===//
187 // DenseMap specialization
188 //===----------------------------------------------------------------------===//
189 
190 unsigned DenseMapInfo<DebugLoc>::getHashValue(const DebugLoc &Key) {
191   return static_cast<unsigned>(hash_combine(Key.LineCol, Key.ScopeIdx));
192 }
193 
194 //===----------------------------------------------------------------------===//
195 // LLVMContextImpl Implementation
196 //===----------------------------------------------------------------------===//
197 
198 int LLVMContextImpl::getOrAddScopeRecordIdxEntry(MDNode *Scope,
199                                                  int ExistingIdx) {
200   // If we already have an entry for this scope, return it.
201   int &Idx = ScopeRecordIdx[Scope];
202   if (Idx) return Idx;
203 
204   // If we don't have an entry, but ExistingIdx is specified, use it.
205   if (ExistingIdx)
206     return Idx = ExistingIdx;
207 
208   // Otherwise add a new entry.
209 
210   // Start out ScopeRecords with a minimal reasonable size to avoid
211   // excessive reallocation starting out.
212   if (ScopeRecords.empty())
213     ScopeRecords.reserve(128);
214 
215   // Index is biased by 1 for index.
216   Idx = ScopeRecords.size()+1;
217   ScopeRecords.push_back(DebugRecVH(Scope, this, Idx));
218   return Idx;
219 }
220 
221 int LLVMContextImpl::getOrAddScopeInlinedAtIdxEntry(MDNode *Scope, MDNode *IA,
222                                                     int ExistingIdx) {
223   // If we already have an entry, return it.
224   int &Idx = ScopeInlinedAtIdx[std::make_pair(Scope, IA)];
225   if (Idx) return Idx;
226 
227   // If we don't have an entry, but ExistingIdx is specified, use it.
228   if (ExistingIdx)
229     return Idx = ExistingIdx;
230 
231   // Start out ScopeInlinedAtRecords with a minimal reasonable size to avoid
232   // excessive reallocation starting out.
233   if (ScopeInlinedAtRecords.empty())
234     ScopeInlinedAtRecords.reserve(128);
235 
236   // Index is biased by 1 and negated.
237   Idx = -ScopeInlinedAtRecords.size()-1;
238   ScopeInlinedAtRecords.push_back(std::make_pair(DebugRecVH(Scope, this, Idx),
239                                                  DebugRecVH(IA, this, Idx)));
240   return Idx;
241 }
242 
243 
244 //===----------------------------------------------------------------------===//
245 // DebugRecVH Implementation
246 //===----------------------------------------------------------------------===//
247 
248 /// deleted - The MDNode this is pointing to got deleted, so this pointer needs
249 /// to drop to null and we need remove our entry from the DenseMap.
250 void DebugRecVH::deleted() {
251   // If this is a non-canonical reference, just drop the value to null, we know
252   // it doesn't have a map entry.
253   if (Idx == 0) {
254     setValPtr(nullptr);
255     return;
256   }
257 
258   MDNode *Cur = get();
259 
260   // If the index is positive, it is an entry in ScopeRecords.
261   if (Idx > 0) {
262     assert(Ctx->ScopeRecordIdx[Cur] == Idx && "Mapping out of date!");
263     Ctx->ScopeRecordIdx.erase(Cur);
264     // Reset this VH to null and we're done.
265     setValPtr(nullptr);
266     Idx = 0;
267     return;
268   }
269 
270   // Otherwise, it is an entry in ScopeInlinedAtRecords, we don't know if it
271   // is the scope or the inlined-at record entry.
272   assert(unsigned(-Idx-1) < Ctx->ScopeInlinedAtRecords.size());
273   std::pair<DebugRecVH, DebugRecVH> &Entry = Ctx->ScopeInlinedAtRecords[-Idx-1];
274   assert((this == &Entry.first || this == &Entry.second) &&
275          "Mapping out of date!");
276 
277   MDNode *OldScope = Entry.first.get();
278   MDNode *OldInlinedAt = Entry.second.get();
279   assert(OldScope && OldInlinedAt &&
280          "Entry should be non-canonical if either val dropped to null");
281 
282   // Otherwise, we do have an entry in it, nuke it and we're done.
283   assert(Ctx->ScopeInlinedAtIdx[std::make_pair(OldScope, OldInlinedAt)] == Idx&&
284          "Mapping out of date");
285   Ctx->ScopeInlinedAtIdx.erase(std::make_pair(OldScope, OldInlinedAt));
286 
287   // Reset this VH to null.  Drop both 'Idx' values to null to indicate that
288   // we're in non-canonical form now.
289   setValPtr(nullptr);
290   Entry.first.Idx = Entry.second.Idx = 0;
291 }
292 
293 void DebugRecVH::allUsesReplacedWith(Value *NewVa) {
294   // If being replaced with a non-mdnode value (e.g. undef) handle this as if
295   // the mdnode got deleted.
296   MDNode *NewVal = dyn_cast<MDNode>(NewVa);
297   if (!NewVal) return deleted();
298 
299   // If this is a non-canonical reference, just change it, we know it already
300   // doesn't have a map entry.
301   if (Idx == 0) {
302     setValPtr(NewVa);
303     return;
304   }
305 
306   MDNode *OldVal = get();
307   assert(OldVal != NewVa && "Node replaced with self?");
308 
309   // If the index is positive, it is an entry in ScopeRecords.
310   if (Idx > 0) {
311     assert(Ctx->ScopeRecordIdx[OldVal] == Idx && "Mapping out of date!");
312     Ctx->ScopeRecordIdx.erase(OldVal);
313     setValPtr(NewVal);
314 
315     int NewEntry = Ctx->getOrAddScopeRecordIdxEntry(NewVal, Idx);
316 
317     // If NewVal already has an entry, this becomes a non-canonical reference,
318     // just drop Idx to 0 to signify this.
319     if (NewEntry != Idx)
320       Idx = 0;
321     return;
322   }
323 
324   // Otherwise, it is an entry in ScopeInlinedAtRecords, we don't know if it
325   // is the scope or the inlined-at record entry.
326   assert(unsigned(-Idx-1) < Ctx->ScopeInlinedAtRecords.size());
327   std::pair<DebugRecVH, DebugRecVH> &Entry = Ctx->ScopeInlinedAtRecords[-Idx-1];
328   assert((this == &Entry.first || this == &Entry.second) &&
329          "Mapping out of date!");
330 
331   MDNode *OldScope = Entry.first.get();
332   MDNode *OldInlinedAt = Entry.second.get();
333   assert(OldScope && OldInlinedAt &&
334          "Entry should be non-canonical if either val dropped to null");
335 
336   // Otherwise, we do have an entry in it, nuke it and we're done.
337   assert(Ctx->ScopeInlinedAtIdx[std::make_pair(OldScope, OldInlinedAt)] == Idx&&
338          "Mapping out of date");
339   Ctx->ScopeInlinedAtIdx.erase(std::make_pair(OldScope, OldInlinedAt));
340 
341   // Reset this VH to the new value.
342   setValPtr(NewVal);
343 
344   int NewIdx = Ctx->getOrAddScopeInlinedAtIdxEntry(Entry.first.get(),
345                                                    Entry.second.get(), Idx);
346   // If NewVal already has an entry, this becomes a non-canonical reference,
347   // just drop Idx to 0 to signify this.
348   if (NewIdx != Idx) {
349     std::pair<DebugRecVH, DebugRecVH> &Entry=Ctx->ScopeInlinedAtRecords[-Idx-1];
350     Entry.first.Idx = Entry.second.Idx = 0;
351   }
352 }
353