1 //===- LexicalScopes.cpp - Collecting lexical scope info -*- C++ -*--------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements LexicalScopes analysis.
12 // This pass collects lexical scope information and maps machine instructions
13 // to respective lexical scopes.
15 //===----------------------------------------------------------------------===//
17 #ifndef LLVM_CODEGEN_LEXICALSCOPES_H
18 #define LLVM_CODEGEN_LEXICALSCOPES_H
20 #include "llvm/ADT/ArrayRef.h"
21 #include "llvm/ADT/DenseMap.h"
22 #include "llvm/ADT/SmallPtrSet.h"
23 #include "llvm/ADT/SmallVector.h"
24 #include "llvm/IR/DebugLoc.h"
25 #include "llvm/IR/Metadata.h"
26 #include "llvm/IR/ValueHandle.h"
32 class MachineBasicBlock;
33 class MachineFunction;
36 //===----------------------------------------------------------------------===//
37 /// InsnRange - This is used to track range of instructions with identical
40 typedef std::pair<const MachineInstr *, const MachineInstr *> InsnRange;
42 //===----------------------------------------------------------------------===//
43 /// LexicalScopes - This class provides interface to collect and use lexical
44 /// scoping information from machine instruction.
48 LexicalScopes() : MF(nullptr), CurrentFnLexicalScope(nullptr) {}
51 /// initialize - Scan machine function and constuct lexical scope nest, resets
52 /// the instance if necessary.
53 void initialize(const MachineFunction &);
55 /// releaseMemory - release memory.
58 /// empty - Return true if there is any lexical scope information available.
59 bool empty() { return CurrentFnLexicalScope == nullptr; }
61 /// isCurrentFunctionScope - Return true if given lexical scope represents
63 bool isCurrentFunctionScope(const LexicalScope *LS) {
64 return LS == CurrentFnLexicalScope;
67 /// getCurrentFunctionScope - Return lexical scope for the current function.
68 LexicalScope *getCurrentFunctionScope() const {
69 return CurrentFnLexicalScope;
72 /// getMachineBasicBlocks - Populate given set using machine basic blocks
73 /// which have machine instructions that belong to lexical scope identified by
75 void getMachineBasicBlocks(DebugLoc DL,
76 SmallPtrSet<const MachineBasicBlock *, 4> &MBBs);
78 /// dominates - Return true if DebugLoc's lexical scope dominates at least one
79 /// machine instruction's lexical scope in a given machine basic block.
80 bool dominates(DebugLoc DL, MachineBasicBlock *MBB);
82 /// findLexicalScope - Find lexical scope, either regular or inlined, for the
83 /// given DebugLoc. Return NULL if not found.
84 LexicalScope *findLexicalScope(DebugLoc DL);
86 /// getAbstractScopesList - Return a reference to list of abstract scopes.
87 ArrayRef<LexicalScope *> getAbstractScopesList() const {
88 return AbstractScopesList;
91 /// findAbstractScope - Find an abstract scope or return NULL.
92 LexicalScope *findAbstractScope(const MDNode *N) {
93 return AbstractScopeMap.lookup(N);
96 /// findInlinedScope - Find an inlined scope for the given DebugLoc or return
98 LexicalScope *findInlinedScope(DebugLoc DL) {
99 return InlinedLexicalScopeMap.lookup(DL);
102 /// findLexicalScope - Find regular lexical scope or return NULL.
103 LexicalScope *findLexicalScope(const MDNode *N) {
104 auto I = LexicalScopeMap.find(N);
105 return I != LexicalScopeMap.end() ? I->second.get() : nullptr;
108 /// dump - Print data structures to dbgs().
112 /// getOrCreateLexicalScope - Find lexical scope for the given DebugLoc. If
113 /// not available then create new lexical scope.
114 LexicalScope *getOrCreateLexicalScope(DebugLoc DL);
116 /// getOrCreateRegularScope - Find or create a regular lexical scope.
117 LexicalScope *getOrCreateRegularScope(MDNode *Scope);
119 /// getOrCreateInlinedScope - Find or create an inlined lexical scope.
120 LexicalScope *getOrCreateInlinedScope(MDNode *Scope, MDNode *InlinedAt);
122 /// getOrCreateAbstractScope - Find or create an abstract lexical scope.
123 LexicalScope *getOrCreateAbstractScope(const MDNode *N);
125 /// extractLexicalScopes - Extract instruction ranges for each lexical scopes
126 /// for the given machine function.
127 void extractLexicalScopes(SmallVectorImpl<InsnRange> &MIRanges,
128 DenseMap<const MachineInstr *, LexicalScope *> &M);
129 void constructScopeNest(LexicalScope *Scope);
131 assignInstructionRanges(SmallVectorImpl<InsnRange> &MIRanges,
132 DenseMap<const MachineInstr *, LexicalScope *> &M);
135 const MachineFunction *MF;
137 /// LexicalScopeMap - Tracks the scopes in the current function. Owns the
138 /// contained LexicalScope*s.
139 DenseMap<const MDNode *, std::unique_ptr<LexicalScope>> LexicalScopeMap;
141 /// InlinedLexicalScopeMap - Tracks inlined function scopes in current
143 DenseMap<DebugLoc, LexicalScope *> InlinedLexicalScopeMap;
145 /// AbstractScopeMap - These scopes are not included LexicalScopeMap.
146 /// AbstractScopes owns its LexicalScope*s.
147 DenseMap<const MDNode *, LexicalScope *> AbstractScopeMap;
149 /// AbstractScopesList - Tracks abstract scopes constructed while processing
151 SmallVector<LexicalScope *, 4> AbstractScopesList;
153 /// CurrentFnLexicalScope - Top level scope for the current function.
155 LexicalScope *CurrentFnLexicalScope;
158 //===----------------------------------------------------------------------===//
159 /// LexicalScope - This class is used to track scope information.
164 LexicalScope(LexicalScope *P, const MDNode *D, const MDNode *I, bool A)
165 : Parent(P), Desc(D), InlinedAtLocation(I), AbstractScope(A),
166 LastInsn(nullptr), FirstInsn(nullptr), DFSIn(0), DFSOut(0) {
168 Parent->addChild(this);
172 LexicalScope *getParent() const { return Parent; }
173 const MDNode *getDesc() const { return Desc; }
174 const MDNode *getInlinedAt() const { return InlinedAtLocation; }
175 const MDNode *getScopeNode() const { return Desc; }
176 bool isAbstractScope() const { return AbstractScope; }
177 SmallVectorImpl<LexicalScope *> &getChildren() { return Children; }
178 SmallVectorImpl<InsnRange> &getRanges() { return Ranges; }
180 /// addChild - Add a child scope.
181 void addChild(LexicalScope *S) { Children.push_back(S); }
183 /// openInsnRange - This scope covers instruction range starting from MI.
184 void openInsnRange(const MachineInstr *MI) {
189 Parent->openInsnRange(MI);
192 /// extendInsnRange - Extend the current instruction range covered by
194 void extendInsnRange(const MachineInstr *MI) {
195 assert(FirstInsn && "MI Range is not open!");
198 Parent->extendInsnRange(MI);
201 /// closeInsnRange - Create a range based on FirstInsn and LastInsn collected
202 /// until now. This is used when a new scope is encountered while walking
203 /// machine instructions.
204 void closeInsnRange(LexicalScope *NewScope = nullptr) {
205 assert(LastInsn && "Last insn missing!");
206 Ranges.push_back(InsnRange(FirstInsn, LastInsn));
209 // If Parent dominates NewScope then do not close Parent's instruction
211 if (Parent && (!NewScope || !Parent->dominates(NewScope)))
212 Parent->closeInsnRange(NewScope);
215 /// dominates - Return true if current scope dominates given lexical scope.
216 bool dominates(const LexicalScope *S) const {
219 if (DFSIn < S->getDFSIn() && DFSOut > S->getDFSOut())
224 // Depth First Search support to walk and manipulate LexicalScope hierarchy.
225 unsigned getDFSOut() const { return DFSOut; }
226 void setDFSOut(unsigned O) { DFSOut = O; }
227 unsigned getDFSIn() const { return DFSIn; }
228 void setDFSIn(unsigned I) { DFSIn = I; }
230 /// dump - print lexical scope.
231 void dump(unsigned Indent = 0) const;
234 LexicalScope *Parent; // Parent to this scope.
235 AssertingVH<const MDNode> Desc; // Debug info descriptor.
236 AssertingVH<const MDNode> InlinedAtLocation; // Location at which this
238 bool AbstractScope; // Abstract Scope
239 SmallVector<LexicalScope *, 4> Children; // Scopes defined in scope.
240 // Contents not owned.
241 SmallVector<InsnRange, 4> Ranges;
243 const MachineInstr *LastInsn; // Last instruction of this scope.
244 const MachineInstr *FirstInsn; // First instruction of this scope.
245 unsigned DFSIn, DFSOut; // In & Out Depth use to determine
249 } // end llvm namespace