LLVM 19.0.0git
LexicalScopes.h
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1//===- LexicalScopes.cpp - Collecting lexical scope info --------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements LexicalScopes analysis.
10//
11// This pass collects lexical scope information and maps machine instructions
12// to respective lexical scopes.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_CODEGEN_LEXICALSCOPES_H
17#define LLVM_CODEGEN_LEXICALSCOPES_H
18
19#include "llvm/ADT/ArrayRef.h"
20#include "llvm/ADT/DenseMap.h"
24#include <cassert>
25#include <unordered_map>
26#include <utility>
27
28namespace llvm {
29
30class MachineBasicBlock;
31class MachineFunction;
32class MachineInstr;
33class MDNode;
34
35//===----------------------------------------------------------------------===//
36/// InsnRange - This is used to track range of instructions with identical
37/// lexical scope.
38///
39using InsnRange = std::pair<const MachineInstr *, const MachineInstr *>;
40
41//===----------------------------------------------------------------------===//
42/// LexicalScope - This class is used to track scope information.
43///
45public:
47 bool A)
48 : Parent(P), Desc(D), InlinedAtLocation(I), AbstractScope(A) {
49 assert(D);
50 assert(D->getSubprogram()->getUnit()->getEmissionKind() !=
52 "Don't build lexical scopes for non-debug locations");
53 assert(D->isResolved() && "Expected resolved node");
54 assert((!I || I->isResolved()) && "Expected resolved node");
55 if (Parent)
56 Parent->addChild(this);
57 }
58
59 // Accessors.
60 LexicalScope *getParent() const { return Parent; }
61 const MDNode *getDesc() const { return Desc; }
62 const DILocation *getInlinedAt() const { return InlinedAtLocation; }
63 const DILocalScope *getScopeNode() const { return Desc; }
64 bool isAbstractScope() const { return AbstractScope; }
67
68 /// addChild - Add a child scope.
69 void addChild(LexicalScope *S) { Children.push_back(S); }
70
71 /// openInsnRange - This scope covers instruction range starting from MI.
73 if (!FirstInsn)
74 FirstInsn = MI;
75
76 if (Parent)
77 Parent->openInsnRange(MI);
78 }
79
80 /// extendInsnRange - Extend the current instruction range covered by
81 /// this scope.
83 assert(FirstInsn && "MI Range is not open!");
84 LastInsn = MI;
85 if (Parent)
86 Parent->extendInsnRange(MI);
87 }
88
89 /// closeInsnRange - Create a range based on FirstInsn and LastInsn collected
90 /// until now. This is used when a new scope is encountered while walking
91 /// machine instructions.
92 void closeInsnRange(LexicalScope *NewScope = nullptr) {
93 assert(LastInsn && "Last insn missing!");
94 Ranges.push_back(InsnRange(FirstInsn, LastInsn));
95 FirstInsn = nullptr;
96 LastInsn = nullptr;
97 // If Parent dominates NewScope then do not close Parent's instruction
98 // range.
99 if (Parent && (!NewScope || !Parent->dominates(NewScope)))
100 Parent->closeInsnRange(NewScope);
101 }
102
103 /// dominates - Return true if current scope dominates given lexical scope.
104 bool dominates(const LexicalScope *S) const {
105 if (S == this)
106 return true;
107 if (DFSIn < S->getDFSIn() && DFSOut > S->getDFSOut())
108 return true;
109 return false;
110 }
111
112 // Depth First Search support to walk and manipulate LexicalScope hierarchy.
113 unsigned getDFSOut() const { return DFSOut; }
114 void setDFSOut(unsigned O) { DFSOut = O; }
115 unsigned getDFSIn() const { return DFSIn; }
116 void setDFSIn(unsigned I) { DFSIn = I; }
117
118 /// dump - print lexical scope.
119 void dump(unsigned Indent = 0) const;
120
121private:
122 LexicalScope *Parent; // Parent to this scope.
123 const DILocalScope *Desc; // Debug info descriptor.
124 const DILocation *InlinedAtLocation; // Location at which this
125 // scope is inlined.
126 bool AbstractScope; // Abstract Scope
127 SmallVector<LexicalScope *, 4> Children; // Scopes defined in scope.
128 // Contents not owned.
130
131 const MachineInstr *LastInsn = nullptr; // Last instruction of this scope.
132 const MachineInstr *FirstInsn = nullptr; // First instruction of this scope.
133 unsigned DFSIn = 0; // In & Out Depth use to determine scope nesting.
134 unsigned DFSOut = 0;
135};
136
137//===----------------------------------------------------------------------===//
138/// LexicalScopes - This class provides interface to collect and use lexical
139/// scoping information from machine instruction.
140///
142public:
143 LexicalScopes() = default;
144
145 /// initialize - Scan machine function and constuct lexical scope nest, resets
146 /// the instance if necessary.
147 void initialize(const MachineFunction &);
148
149 /// releaseMemory - release memory.
150 void reset();
151
152 /// empty - Return true if there is any lexical scope information available.
153 bool empty() { return CurrentFnLexicalScope == nullptr; }
154
155 /// getCurrentFunctionScope - Return lexical scope for the current function.
157 return CurrentFnLexicalScope;
158 }
159
160 /// getMachineBasicBlocks - Populate given set using machine basic blocks
161 /// which have machine instructions that belong to lexical scope identified by
162 /// DebugLoc.
165
166 /// Return true if DebugLoc's lexical scope dominates at least one machine
167 /// instruction's lexical scope in a given machine basic block.
169
170 /// findLexicalScope - Find lexical scope, either regular or inlined, for the
171 /// given DebugLoc. Return NULL if not found.
173
174 /// getAbstractScopesList - Return a reference to list of abstract scopes.
176 return AbstractScopesList;
177 }
178
179 /// findAbstractScope - Find an abstract scope or return null.
181 auto I = AbstractScopeMap.find(N);
182 return I != AbstractScopeMap.end() ? &I->second : nullptr;
183 }
184
185 /// findInlinedScope - Find an inlined scope for the given scope/inlined-at.
187 auto I = InlinedLexicalScopeMap.find(std::make_pair(N, IA));
188 return I != InlinedLexicalScopeMap.end() ? &I->second : nullptr;
189 }
190
191 /// findLexicalScope - Find regular lexical scope or return null.
193 auto I = LexicalScopeMap.find(N);
194 return I != LexicalScopeMap.end() ? &I->second : nullptr;
195 }
196
197 /// getOrCreateAbstractScope - Find or create an abstract lexical scope.
199
200private:
201 /// getOrCreateLexicalScope - Find lexical scope for the given Scope/IA. If
202 /// not available then create new lexical scope.
203 LexicalScope *getOrCreateLexicalScope(const DILocalScope *Scope,
204 const DILocation *IA = nullptr);
205 LexicalScope *getOrCreateLexicalScope(const DILocation *DL) {
206 return DL ? getOrCreateLexicalScope(DL->getScope(), DL->getInlinedAt())
207 : nullptr;
208 }
209
210 /// getOrCreateRegularScope - Find or create a regular lexical scope.
211 LexicalScope *getOrCreateRegularScope(const DILocalScope *Scope);
212
213 /// getOrCreateInlinedScope - Find or create an inlined lexical scope.
214 LexicalScope *getOrCreateInlinedScope(const DILocalScope *Scope,
215 const DILocation *InlinedAt);
216
217 /// extractLexicalScopes - Extract instruction ranges for each lexical scopes
218 /// for the given machine function.
219 void extractLexicalScopes(SmallVectorImpl<InsnRange> &MIRanges,
220 DenseMap<const MachineInstr *, LexicalScope *> &M);
221 void constructScopeNest(LexicalScope *Scope);
222 void
223 assignInstructionRanges(SmallVectorImpl<InsnRange> &MIRanges,
224 DenseMap<const MachineInstr *, LexicalScope *> &M);
225
226 const MachineFunction *MF = nullptr;
227
228 /// LexicalScopeMap - Tracks the scopes in the current function.
229 // Use an unordered_map to ensure value pointer validity over insertion.
230 std::unordered_map<const DILocalScope *, LexicalScope> LexicalScopeMap;
231
232 /// InlinedLexicalScopeMap - Tracks inlined function scopes in current
233 /// function.
234 std::unordered_map<std::pair<const DILocalScope *, const DILocation *>,
235 LexicalScope,
236 pair_hash<const DILocalScope *, const DILocation *>>
237 InlinedLexicalScopeMap;
238
239 /// AbstractScopeMap - These scopes are not included LexicalScopeMap.
240 // Use an unordered_map to ensure value pointer validity over insertion.
241 std::unordered_map<const DILocalScope *, LexicalScope> AbstractScopeMap;
242
243 /// AbstractScopesList - Tracks abstract scopes constructed while processing
244 /// a function.
245 SmallVector<LexicalScope *, 4> AbstractScopesList;
246
247 /// CurrentFnLexicalScope - Top level scope for the current function.
248 ///
249 LexicalScope *CurrentFnLexicalScope = nullptr;
250
251 /// Map a location to the set of basic blocks it dominates. This is a cache
252 /// for \ref LexicalScopes::getMachineBasicBlocks results.
253 using BlockSetT = SmallPtrSet<const MachineBasicBlock *, 4>;
254 DenseMap<const DILocation *, std::unique_ptr<BlockSetT>> DominatedBlocks;
255};
256
257} // end namespace llvm
258
259#endif // LLVM_CODEGEN_LEXICALSCOPES_H
MachineBasicBlock & MBB
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
static GCRegistry::Add< ErlangGC > A("erlang", "erlang-compatible garbage collector")
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
This file defines the DenseMap class.
IRTranslator LLVM IR MI
#define I(x, y, z)
Definition: MD5.cpp:58
#define P(N)
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This file defines the SmallPtrSet class.
This file defines the SmallVector class.
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
Definition: ArrayRef.h:41
A scope for locals.
Debug location.
LexicalScope - This class is used to track scope information.
Definition: LexicalScopes.h:44
unsigned getDFSIn() const
void extendInsnRange(const MachineInstr *MI)
extendInsnRange - Extend the current instruction range covered by this scope.
Definition: LexicalScopes.h:82
SmallVectorImpl< LexicalScope * > & getChildren()
Definition: LexicalScopes.h:65
const DILocation * getInlinedAt() const
Definition: LexicalScopes.h:62
SmallVectorImpl< InsnRange > & getRanges()
Definition: LexicalScopes.h:66
LexicalScope(LexicalScope *P, const DILocalScope *D, const DILocation *I, bool A)
Definition: LexicalScopes.h:46
const DILocalScope * getScopeNode() const
Definition: LexicalScopes.h:63
void setDFSOut(unsigned O)
unsigned getDFSOut() const
void openInsnRange(const MachineInstr *MI)
openInsnRange - This scope covers instruction range starting from MI.
Definition: LexicalScopes.h:72
void addChild(LexicalScope *S)
addChild - Add a child scope.
Definition: LexicalScopes.h:69
void dump(unsigned Indent=0) const
dump - print lexical scope.
void setDFSIn(unsigned I)
LexicalScope * getParent() const
Definition: LexicalScopes.h:60
const MDNode * getDesc() const
Definition: LexicalScopes.h:61
bool dominates(const LexicalScope *S) const
dominates - Return true if current scope dominates given lexical scope.
void closeInsnRange(LexicalScope *NewScope=nullptr)
closeInsnRange - Create a range based on FirstInsn and LastInsn collected until now.
Definition: LexicalScopes.h:92
bool isAbstractScope() const
Definition: LexicalScopes.h:64
LexicalScopes - This class provides interface to collect and use lexical scoping information from mac...
void reset()
releaseMemory - release memory.
LexicalScope * getOrCreateAbstractScope(const DILocalScope *Scope)
getOrCreateAbstractScope - Find or create an abstract lexical scope.
void initialize(const MachineFunction &)
initialize - Scan machine function and constuct lexical scope nest, resets the instance if necessary.
LexicalScope * findLexicalScope(const DILocation *DL)
findLexicalScope - Find lexical scope, either regular or inlined, for the given DebugLoc.
LexicalScopes()=default
void getMachineBasicBlocks(const DILocation *DL, SmallPtrSetImpl< const MachineBasicBlock * > &MBBs)
getMachineBasicBlocks - Populate given set using machine basic blocks which have machine instructions...
ArrayRef< LexicalScope * > getAbstractScopesList() const
getAbstractScopesList - Return a reference to list of abstract scopes.
LexicalScope * findInlinedScope(const DILocalScope *N, const DILocation *IA)
findInlinedScope - Find an inlined scope for the given scope/inlined-at.
LexicalScope * findAbstractScope(const DILocalScope *N)
findAbstractScope - Find an abstract scope or return null.
LexicalScope * findLexicalScope(const DILocalScope *N)
findLexicalScope - Find regular lexical scope or return null.
bool empty()
empty - Return true if there is any lexical scope information available.
bool dominates(const DILocation *DL, MachineBasicBlock *MBB)
Return true if DebugLoc's lexical scope dominates at least one machine instruction's lexical scope in...
LexicalScope * getCurrentFunctionScope() const
getCurrentFunctionScope - Return lexical scope for the current function.
Metadata node.
Definition: Metadata.h:1067
Representation of each machine instruction.
Definition: MachineInstr.h:69
A templated base class for SmallPtrSet which provides the typesafe interface that is common across al...
Definition: SmallPtrSet.h:321
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:586
void push_back(const T &Elt)
Definition: SmallVector.h:426
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1209
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
std::pair< const MachineInstr *, const MachineInstr * > InsnRange
InsnRange - This is used to track range of instructions with identical lexical scope.
Definition: LexicalScopes.h:39
#define N
Description of the encoding of one expression Op.