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Devang Patele1649c32011-08-10 19:04:06 +00001//===- 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//===----------------------------------------------------------------------===//
16
Devang Patele1649c32011-08-10 19:04:06 +000017#include "llvm/CodeGen/LexicalScopes.h"
Devang Patele1649c32011-08-10 19:04:06 +000018#include "llvm/CodeGen/MachineFunction.h"
19#include "llvm/CodeGen/MachineInstr.h"
Chandler Carruth9a4c9e52014-03-06 00:46:21 +000020#include "llvm/IR/DebugInfo.h"
Chandler Carruth9fb823b2013-01-02 11:36:10 +000021#include "llvm/IR/Function.h"
Devang Patele1649c32011-08-10 19:04:06 +000022#include "llvm/Support/Debug.h"
23#include "llvm/Support/ErrorHandling.h"
24#include "llvm/Support/FormattedStream.h"
25using namespace llvm;
26
Chandler Carruth1b9dde02014-04-22 02:02:50 +000027#define DEBUG_TYPE "lexicalscopes"
28
Eric Christopherb7dee8a2013-11-20 00:54:28 +000029/// reset - Reset the instance so that it's prepared for another function.
30void LexicalScopes::reset() {
Craig Topperc0196b12014-04-14 00:51:57 +000031 MF = nullptr;
32 CurrentFnLexicalScope = nullptr;
David Blaikie2f143e02014-05-08 22:24:51 +000033 LexicalScopeMap.clear();
34 AbstractScopeMap.clear();
Devang Patele1649c32011-08-10 19:04:06 +000035 InlinedLexicalScopeMap.clear();
36 AbstractScopesList.clear();
37}
38
39/// initialize - Scan machine function and constuct lexical scope nest.
40void LexicalScopes::initialize(const MachineFunction &Fn) {
Eric Christopherb7dee8a2013-11-20 00:54:28 +000041 reset();
Devang Patele1649c32011-08-10 19:04:06 +000042 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}
51
52/// extractLexicalScopes - Extract instruction ranges for each lexical scopes
53/// for the given machine function.
Eric Christopher6211e4b2013-11-20 00:54:19 +000054void LexicalScopes::extractLexicalScopes(
55 SmallVectorImpl<InsnRange> &MIRanges,
56 DenseMap<const MachineInstr *, LexicalScope *> &MI2ScopeMap) {
Devang Patele1649c32011-08-10 19:04:06 +000057
58 // Scan each instruction and create scopes. First build working set of scopes.
Alexey Samsonov41b977d2014-04-30 18:29:51 +000059 for (const auto &MBB : *MF) {
Craig Topperc0196b12014-04-14 00:51:57 +000060 const MachineInstr *RangeBeginMI = nullptr;
61 const MachineInstr *PrevMI = nullptr;
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +000062 const DILocation *PrevDL = nullptr;
Alexey Samsonovf74bde62014-04-30 22:17:38 +000063 for (const auto &MInsn : MBB) {
Devang Patele1649c32011-08-10 19:04:06 +000064 // Check if instruction has valid location information.
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +000065 const DILocation *MIDL = MInsn.getDebugLoc();
Duncan P. N. Exon Smith9dffcd02015-03-30 19:14:47 +000066 if (!MIDL) {
Alexey Samsonovf74bde62014-04-30 22:17:38 +000067 PrevMI = &MInsn;
Devang Patele1649c32011-08-10 19:04:06 +000068 continue;
69 }
70
71 // If scope has not changed then skip this instruction.
72 if (MIDL == PrevDL) {
Alexey Samsonovf74bde62014-04-30 22:17:38 +000073 PrevMI = &MInsn;
Devang Patele1649c32011-08-10 19:04:06 +000074 continue;
75 }
76
77 // Ignore DBG_VALUE. It does not contribute to any instruction in output.
Alexey Samsonovf74bde62014-04-30 22:17:38 +000078 if (MInsn.isDebugValue())
Devang Patele1649c32011-08-10 19:04:06 +000079 continue;
80
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 }
89
90 // This is a beginning of a new instruction range.
Alexey Samsonovf74bde62014-04-30 22:17:38 +000091 RangeBeginMI = &MInsn;
Devang Patele1649c32011-08-10 19:04:06 +000092
93 // Reset previous markers.
Alexey Samsonovf74bde62014-04-30 22:17:38 +000094 PrevMI = &MInsn;
Devang Patele1649c32011-08-10 19:04:06 +000095 PrevDL = MIDL;
96 }
97
98 // Create last instruction range.
Duncan P. N. Exon Smith9dffcd02015-03-30 19:14:47 +000099 if (RangeBeginMI && PrevMI && PrevDL) {
Devang Patele1649c32011-08-10 19:04:06 +0000100 InsnRange R(RangeBeginMI, PrevMI);
101 MIRanges.push_back(R);
102 MI2ScopeMap[RangeBeginMI] = getOrCreateLexicalScope(PrevDL);
103 }
104 }
105}
106
107/// findLexicalScope - Find lexical scope, either regular or inlined, for the
108/// given DebugLoc. Return NULL if not found.
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000109LexicalScope *LexicalScopes::findLexicalScope(const DILocation *DL) {
110 DILocalScope *Scope = DL->getScope();
Eric Christopher6211e4b2013-11-20 00:54:19 +0000111 if (!Scope)
Craig Topperc0196b12014-04-14 00:51:57 +0000112 return nullptr;
Eric Christopher6647b832011-10-11 22:59:11 +0000113
114 // The scope that we were created with could have an extra file - which
115 // isn't what we care about in this case.
Amjad Abouda5ba9912016-04-21 16:58:49 +0000116 Scope = Scope->getNonLexicalBlockFileScope();
Eric Christopher6211e4b2013-11-20 00:54:19 +0000117
Duncan P. N. Exon Smith5a227ff2015-03-30 21:54:46 +0000118 if (auto *IA = DL->getInlinedAt()) {
David Blaikie9b8c8cd2014-05-14 01:08:28 +0000119 auto I = InlinedLexicalScopeMap.find(std::make_pair(Scope, IA));
120 return I != InlinedLexicalScopeMap.end() ? &I->second : nullptr;
121 }
David Blaikie2f143e02014-05-08 22:24:51 +0000122 return findLexicalScope(Scope);
Devang Patele1649c32011-08-10 19:04:06 +0000123}
124
125/// getOrCreateLexicalScope - Find lexical scope for the given DebugLoc. If
126/// not available then create new lexical scope.
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000127LexicalScope *LexicalScopes::getOrCreateLexicalScope(const DILocalScope *Scope,
128 const DILocation *IA) {
Duncan P. N. Exon Smith82eba742015-03-30 23:47:26 +0000129 if (IA) {
Devang Patele1649c32011-08-10 19:04:06 +0000130 // Create an abstract scope for inlined function.
131 getOrCreateAbstractScope(Scope);
132 // Create an inlined scope for inlined function.
Duncan P. N. Exon Smith82eba742015-03-30 23:47:26 +0000133 return getOrCreateInlinedScope(Scope, IA);
Devang Patele1649c32011-08-10 19:04:06 +0000134 }
Eric Christopher6211e4b2013-11-20 00:54:19 +0000135
Devang Patele1649c32011-08-10 19:04:06 +0000136 return getOrCreateRegularScope(Scope);
137}
138
139/// getOrCreateRegularScope - Find or create a regular lexical scope.
Duncan P. N. Exon Smith33af7a82015-03-30 23:21:21 +0000140LexicalScope *
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000141LexicalScopes::getOrCreateRegularScope(const DILocalScope *Scope) {
Amjad Abouda5ba9912016-04-21 16:58:49 +0000142 assert(Scope && "Invalid Scope encoding!");
143 Scope = Scope->getNonLexicalBlockFileScope();
Eric Christopher6211e4b2013-11-20 00:54:19 +0000144
David Blaikie2f143e02014-05-08 22:24:51 +0000145 auto I = LexicalScopeMap.find(Scope);
146 if (I != LexicalScopeMap.end())
147 return &I->second;
Devang Patele1649c32011-08-10 19:04:06 +0000148
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000149 // FIXME: Should the following dyn_cast be DILexicalBlock?
Craig Topperc0196b12014-04-14 00:51:57 +0000150 LexicalScope *Parent = nullptr;
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000151 if (auto *Block = dyn_cast<DILexicalBlockBase>(Scope))
Duncan P. N. Exon Smith82eba742015-03-30 23:47:26 +0000152 Parent = getOrCreateLexicalScope(Block->getScope());
Aaron Ballmanf17583e2015-02-16 18:21:19 +0000153 I = LexicalScopeMap.emplace(std::piecewise_construct,
154 std::forward_as_tuple(Scope),
Duncan P. N. Exon Smith33af7a82015-03-30 23:21:21 +0000155 std::forward_as_tuple(Parent, Scope, nullptr,
156 false)).first;
David Blaikie2f143e02014-05-08 22:24:51 +0000157
David Blaikie3dfe4782014-10-14 18:22:52 +0000158 if (!Parent) {
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000159 assert(cast<DISubprogram>(Scope)->describes(MF->getFunction()));
David Blaikie3dfe4782014-10-14 18:22:52 +0000160 assert(!CurrentFnLexicalScope);
David Blaikie2f143e02014-05-08 22:24:51 +0000161 CurrentFnLexicalScope = &I->second;
David Blaikie3dfe4782014-10-14 18:22:52 +0000162 }
Eric Christopher6211e4b2013-11-20 00:54:19 +0000163
David Blaikie2f143e02014-05-08 22:24:51 +0000164 return &I->second;
Devang Patele1649c32011-08-10 19:04:06 +0000165}
166
167/// getOrCreateInlinedScope - Find or create an inlined lexical scope.
Duncan P. N. Exon Smith33af7a82015-03-30 23:21:21 +0000168LexicalScope *
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000169LexicalScopes::getOrCreateInlinedScope(const DILocalScope *Scope,
170 const DILocation *InlinedAt) {
Amjad Abouda5ba9912016-04-21 16:58:49 +0000171 assert(Scope && "Invalid Scope encoding!");
172 Scope = Scope->getNonLexicalBlockFileScope();
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000173 std::pair<const DILocalScope *, const DILocation *> P(Scope, InlinedAt);
David Blaikie9b8c8cd2014-05-14 01:08:28 +0000174 auto I = InlinedLexicalScopeMap.find(P);
175 if (I != InlinedLexicalScopeMap.end())
David Blaikie2f143e02014-05-08 22:24:51 +0000176 return &I->second;
Devang Patele1649c32011-08-10 19:04:06 +0000177
David Blaikie9b8c8cd2014-05-14 01:08:28 +0000178 LexicalScope *Parent;
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000179 if (auto *Block = dyn_cast<DILexicalBlockBase>(Scope))
Duncan P. N. Exon Smith33af7a82015-03-30 23:21:21 +0000180 Parent = getOrCreateInlinedScope(Block->getScope(), InlinedAt);
David Blaikie9b8c8cd2014-05-14 01:08:28 +0000181 else
Duncan P. N. Exon Smith33af7a82015-03-30 23:21:21 +0000182 Parent = getOrCreateLexicalScope(InlinedAt);
David Blaikie9b8c8cd2014-05-14 01:08:28 +0000183
David Blaikie9b8c8cd2014-05-14 01:08:28 +0000184 I = InlinedLexicalScopeMap.emplace(std::piecewise_construct,
Aaron Ballmanf17583e2015-02-16 18:21:19 +0000185 std::forward_as_tuple(P),
186 std::forward_as_tuple(Parent, Scope,
187 InlinedAt, false))
188 .first;
David Blaikie2f143e02014-05-08 22:24:51 +0000189 return &I->second;
Devang Patele1649c32011-08-10 19:04:06 +0000190}
191
192/// getOrCreateAbstractScope - Find or create an abstract lexical scope.
Duncan P. N. Exon Smith33af7a82015-03-30 23:21:21 +0000193LexicalScope *
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000194LexicalScopes::getOrCreateAbstractScope(const DILocalScope *Scope) {
Duncan P. N. Exon Smith33af7a82015-03-30 23:21:21 +0000195 assert(Scope && "Invalid Scope encoding!");
Amjad Abouda5ba9912016-04-21 16:58:49 +0000196 Scope = Scope->getNonLexicalBlockFileScope();
David Blaikieea862262014-05-25 18:11:35 +0000197 auto I = AbstractScopeMap.find(Scope);
David Blaikie2f143e02014-05-08 22:24:51 +0000198 if (I != AbstractScopeMap.end())
199 return &I->second;
Devang Patele1649c32011-08-10 19:04:06 +0000200
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000201 // FIXME: Should the following isa be DILexicalBlock?
Craig Topperc0196b12014-04-14 00:51:57 +0000202 LexicalScope *Parent = nullptr;
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000203 if (auto *Block = dyn_cast<DILexicalBlockBase>(Scope))
Duncan P. N. Exon Smith33af7a82015-03-30 23:21:21 +0000204 Parent = getOrCreateAbstractScope(Block->getScope());
205
David Blaikie2f143e02014-05-08 22:24:51 +0000206 I = AbstractScopeMap.emplace(std::piecewise_construct,
David Blaikieea862262014-05-25 18:11:35 +0000207 std::forward_as_tuple(Scope),
208 std::forward_as_tuple(Parent, Scope,
David Blaikie2f143e02014-05-08 22:24:51 +0000209 nullptr, true)).first;
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000210 if (isa<DISubprogram>(Scope))
David Blaikie2f143e02014-05-08 22:24:51 +0000211 AbstractScopesList.push_back(&I->second);
212 return &I->second;
Devang Patele1649c32011-08-10 19:04:06 +0000213}
214
215/// constructScopeNest
216void LexicalScopes::constructScopeNest(LexicalScope *Scope) {
Eric Christopher6211e4b2013-11-20 00:54:19 +0000217 assert(Scope && "Unable to calculate scope dominance graph!");
Devang Patele1649c32011-08-10 19:04:06 +0000218 SmallVector<LexicalScope *, 4> WorkStack;
219 WorkStack.push_back(Scope);
220 unsigned Counter = 0;
221 while (!WorkStack.empty()) {
222 LexicalScope *WS = WorkStack.back();
Craig Topper80170e52013-07-03 04:30:58 +0000223 const SmallVectorImpl<LexicalScope *> &Children = WS->getChildren();
Devang Patele1649c32011-08-10 19:04:06 +0000224 bool visitedChildren = false;
Adrian Prantl16b2ace2016-09-28 17:31:17 +0000225 for (auto &ChildScope : Children)
Devang Patele1649c32011-08-10 19:04:06 +0000226 if (!ChildScope->getDFSOut()) {
227 WorkStack.push_back(ChildScope);
228 visitedChildren = true;
229 ChildScope->setDFSIn(++Counter);
230 break;
231 }
Devang Patele1649c32011-08-10 19:04:06 +0000232 if (!visitedChildren) {
233 WorkStack.pop_back();
234 WS->setDFSOut(++Counter);
235 }
236 }
237}
238
Devang Patel784077e2011-08-10 23:58:09 +0000239/// assignInstructionRanges - Find ranges of instructions covered by each
240/// lexical scope.
Eric Christopher6211e4b2013-11-20 00:54:19 +0000241void LexicalScopes::assignInstructionRanges(
242 SmallVectorImpl<InsnRange> &MIRanges,
243 DenseMap<const MachineInstr *, LexicalScope *> &MI2ScopeMap) {
244
Craig Topperc0196b12014-04-14 00:51:57 +0000245 LexicalScope *PrevLexicalScope = nullptr;
Adrian Prantl16b2ace2016-09-28 17:31:17 +0000246 for (const auto &R : MIRanges) {
Devang Patele1649c32011-08-10 19:04:06 +0000247 LexicalScope *S = MI2ScopeMap.lookup(R.first);
Eric Christopher6211e4b2013-11-20 00:54:19 +0000248 assert(S && "Lost LexicalScope for a machine instruction!");
Devang Patele1649c32011-08-10 19:04:06 +0000249 if (PrevLexicalScope && !PrevLexicalScope->dominates(S))
250 PrevLexicalScope->closeInsnRange(S);
251 S->openInsnRange(R.first);
252 S->extendInsnRange(R.second);
253 PrevLexicalScope = S;
254 }
255
256 if (PrevLexicalScope)
257 PrevLexicalScope->closeInsnRange();
258}
259
260/// getMachineBasicBlocks - Populate given set using machine basic blocks which
Eric Christopher6211e4b2013-11-20 00:54:19 +0000261/// have machine instructions that belong to lexical scope identified by
Devang Patele1649c32011-08-10 19:04:06 +0000262/// DebugLoc.
Eric Christopher6211e4b2013-11-20 00:54:19 +0000263void LexicalScopes::getMachineBasicBlocks(
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000264 const DILocation *DL, SmallPtrSetImpl<const MachineBasicBlock *> &MBBs) {
Devang Patele1649c32011-08-10 19:04:06 +0000265 MBBs.clear();
266 LexicalScope *Scope = getOrCreateLexicalScope(DL);
267 if (!Scope)
268 return;
Eric Christopher6211e4b2013-11-20 00:54:19 +0000269
Devang Pateldb4374a2011-08-12 18:01:34 +0000270 if (Scope == CurrentFnLexicalScope) {
Alexey Samsonov41b977d2014-04-30 18:29:51 +0000271 for (const auto &MBB : *MF)
272 MBBs.insert(&MBB);
Devang Pateldb4374a2011-08-12 18:01:34 +0000273 return;
274 }
275
Craig Topper80170e52013-07-03 04:30:58 +0000276 SmallVectorImpl<InsnRange> &InsnRanges = Scope->getRanges();
Adrian Prantl16b2ace2016-09-28 17:31:17 +0000277 for (auto &R : InsnRanges)
Devang Patele1649c32011-08-10 19:04:06 +0000278 MBBs.insert(R.first->getParent());
Devang Patele1649c32011-08-10 19:04:06 +0000279}
280
281/// dominates - Return true if DebugLoc's lexical scope dominates at least one
282/// machine instruction's lexical scope in a given machine basic block.
Duncan P. N. Exon Smitha9308c42015-04-29 16:38:44 +0000283bool LexicalScopes::dominates(const DILocation *DL, MachineBasicBlock *MBB) {
Devang Patele1649c32011-08-10 19:04:06 +0000284 LexicalScope *Scope = getOrCreateLexicalScope(DL);
285 if (!Scope)
286 return false;
Devang Pateldb4374a2011-08-12 18:01:34 +0000287
288 // Current function scope covers all basic blocks in the function.
289 if (Scope == CurrentFnLexicalScope && MBB->getParent() == MF)
290 return true;
291
Devang Patele1649c32011-08-10 19:04:06 +0000292 bool Result = false;
Adrian Prantl16b2ace2016-09-28 17:31:17 +0000293 for (auto &I : *MBB) {
294 if (const DILocation *IDL = I.getDebugLoc())
Duncan P. N. Exon Smith3386e0e2015-03-30 23:58:59 +0000295 if (LexicalScope *IScope = getOrCreateLexicalScope(IDL))
296 if (Scope->dominates(IScope))
297 return true;
Devang Patele1649c32011-08-10 19:04:06 +0000298 }
299 return Result;
300}
301
Devang Patele1649c32011-08-10 19:04:06 +0000302/// dump - Print data structures.
Manman Rene498b252013-02-02 00:02:03 +0000303void LexicalScope::dump(unsigned Indent) const {
Devang Patele1649c32011-08-10 19:04:06 +0000304#ifndef NDEBUG
305 raw_ostream &err = dbgs();
Manman Rene498b252013-02-02 00:02:03 +0000306 err.indent(Indent);
Devang Patele1649c32011-08-10 19:04:06 +0000307 err << "DFSIn: " << DFSIn << " DFSOut: " << DFSOut << "\n";
308 const MDNode *N = Desc;
Manman Rene498b252013-02-02 00:02:03 +0000309 err.indent(Indent);
Devang Patele1649c32011-08-10 19:04:06 +0000310 N->dump();
311 if (AbstractScope)
Manman Rene498b252013-02-02 00:02:03 +0000312 err << std::string(Indent, ' ') << "Abstract Scope\n";
Devang Patele1649c32011-08-10 19:04:06 +0000313
Devang Patele1649c32011-08-10 19:04:06 +0000314 if (!Children.empty())
Manman Rene498b252013-02-02 00:02:03 +0000315 err << std::string(Indent + 2, ' ') << "Children ...\n";
Devang Patele1649c32011-08-10 19:04:06 +0000316 for (unsigned i = 0, e = Children.size(); i != e; ++i)
317 if (Children[i] != this)
Manman Rene498b252013-02-02 00:02:03 +0000318 Children[i]->dump(Indent + 2);
Devang Patele1649c32011-08-10 19:04:06 +0000319#endif
320}