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/Metadata.h"
25 #include "llvm/Support/DebugLoc.h"
26 #include "llvm/Support/ValueHandle.h"
31 class MachineBasicBlock;
32 class MachineFunction;
35 //===----------------------------------------------------------------------===//
36 /// InsnRange - This is used to track range of instructions with identical
39 typedef std::pair<const MachineInstr *, const MachineInstr *> InsnRange;
41 //===----------------------------------------------------------------------===//
42 /// LexicalScopes - This class provides interface to collect and use lexical
43 /// scoping information from machine instruction.
47 LexicalScopes() : MF(NULL), CurrentFnLexicalScope(NULL) { }
48 virtual ~LexicalScopes();
50 /// initialize - Scan machine function and constuct lexical scope nest.
51 virtual void initialize(const MachineFunction &);
53 /// releaseMemory - release memory.
54 virtual void releaseMemory();
56 /// empty - Return true if there is any lexical scope information available.
57 bool empty() { return CurrentFnLexicalScope == NULL; }
59 /// isCurrentFunctionScope - Return true if given lexical scope represents
61 bool isCurrentFunctionScope(const LexicalScope *LS) {
62 return LS == CurrentFnLexicalScope;
65 /// getCurrentFunctionScope - Return lexical scope for the current function.
66 LexicalScope *getCurrentFunctionScope() const { return CurrentFnLexicalScope;}
68 /// getMachineBasicBlocks - Populate given set using machine basic blocks
69 /// which have machine instructions that belong to lexical scope identified by
71 void getMachineBasicBlocks(DebugLoc DL,
72 SmallPtrSet<const MachineBasicBlock*, 4> &MBBs);
74 /// dominates - Return true if DebugLoc's lexical scope dominates at least one
75 /// machine instruction's lexical scope in a given machine basic block.
76 bool dominates(DebugLoc DL, MachineBasicBlock *MBB);
78 /// findLexicalScope - Find lexical scope, either regular or inlined, for the
79 /// given DebugLoc. Return NULL if not found.
80 LexicalScope *findLexicalScope(DebugLoc DL);
82 /// getAbstractScopesList - Return a reference to list of abstract scopes.
83 ArrayRef<LexicalScope *> getAbstractScopesList() const {
84 return AbstractScopesList;
87 /// findAbstractScope - Find an abstract scope or return NULL.
88 LexicalScope *findAbstractScope(const MDNode *N) {
89 return AbstractScopeMap.lookup(N);
92 /// findInlinedScope - Find an inlined scope for the given DebugLoc or return
94 LexicalScope *findInlinedScope(DebugLoc DL) {
95 return InlinedLexicalScopeMap.lookup(DL);
98 /// findLexicalScope - Find regular lexical scope or return NULL.
99 LexicalScope *findLexicalScope(const MDNode *N) {
100 return LexicalScopeMap.lookup(N);
103 /// dump - Print data structures to dbgs().
108 /// getOrCreateLexicalScope - Find lexical scope for the given DebugLoc. If
109 /// not available then create new lexical scope.
110 LexicalScope *getOrCreateLexicalScope(DebugLoc DL);
112 /// getOrCreateRegularScope - Find or create a regular lexical scope.
113 LexicalScope *getOrCreateRegularScope(MDNode *Scope);
115 /// getOrCreateInlinedScope - Find or create an inlined lexical scope.
116 LexicalScope *getOrCreateInlinedScope(MDNode *Scope, MDNode *InlinedAt);
118 /// getOrCreateAbstractScope - Find or create an abstract lexical scope.
119 LexicalScope *getOrCreateAbstractScope(const MDNode *N);
121 /// extractLexicalScopes - Extract instruction ranges for each lexical scopes
122 /// for the given machine function.
123 void extractLexicalScopes(SmallVectorImpl<InsnRange> &MIRanges,
124 DenseMap<const MachineInstr *, LexicalScope *> &M);
125 void constructScopeNest(LexicalScope *Scope);
126 void assignInstructionRanges(SmallVectorImpl<InsnRange> &MIRanges,
127 DenseMap<const MachineInstr *, LexicalScope *> &M);
130 const MachineFunction *MF;
132 /// LexicalScopeMap - Tracks the scopes in the current function. Owns the
133 /// contained LexicalScope*s.
134 DenseMap<const MDNode *, LexicalScope *> LexicalScopeMap;
136 /// InlinedLexicalScopeMap - Tracks inlined function scopes in current function.
137 DenseMap<DebugLoc, LexicalScope *> InlinedLexicalScopeMap;
139 /// AbstractScopeMap - These scopes are not included LexicalScopeMap.
140 /// AbstractScopes owns its LexicalScope*s.
141 DenseMap<const MDNode *, LexicalScope *> AbstractScopeMap;
143 /// AbstractScopesList - Tracks abstract scopes constructed while processing
145 SmallVector<LexicalScope *, 4>AbstractScopesList;
147 /// CurrentFnLexicalScope - Top level scope for the current function.
149 LexicalScope *CurrentFnLexicalScope;
152 //===----------------------------------------------------------------------===//
153 /// LexicalScope - This class is used to track scope information.
156 virtual void anchor();
159 LexicalScope(LexicalScope *P, const MDNode *D, const MDNode *I, bool A)
160 : Parent(P), Desc(D), InlinedAtLocation(I), AbstractScope(A),
161 LastInsn(0), FirstInsn(0), DFSIn(0), DFSOut(0) {
163 Parent->addChild(this);
166 virtual ~LexicalScope() {}
169 LexicalScope *getParent() const { return Parent; }
170 const MDNode *getDesc() const { return Desc; }
171 const MDNode *getInlinedAt() const { return InlinedAtLocation; }
172 const MDNode *getScopeNode() const { return Desc; }
173 bool isAbstractScope() const { return AbstractScope; }
174 SmallVector<LexicalScope *, 4> &getChildren() { return Children; }
175 SmallVector<InsnRange, 4> &getRanges() { return Ranges; }
177 /// addChild - Add a child scope.
178 void addChild(LexicalScope *S) { Children.push_back(S); }
180 /// openInsnRange - This scope covers instruction range starting from MI.
181 void openInsnRange(const MachineInstr *MI) {
186 Parent->openInsnRange(MI);
189 /// extendInsnRange - Extend the current instruction range covered by
191 void extendInsnRange(const MachineInstr *MI) {
192 assert (FirstInsn && "MI Range is not open!");
195 Parent->extendInsnRange(MI);
198 /// closeInsnRange - Create a range based on FirstInsn and LastInsn collected
199 /// until now. This is used when a new scope is encountered while walking
200 /// machine instructions.
201 void closeInsnRange(LexicalScope *NewScope = NULL) {
202 assert (LastInsn && "Last insn missing!");
203 Ranges.push_back(InsnRange(FirstInsn, LastInsn));
206 // If Parent dominates NewScope then do not close Parent's instruction
208 if (Parent && (!NewScope || !Parent->dominates(NewScope)))
209 Parent->closeInsnRange(NewScope);
212 /// dominates - Return true if current scope dominates given lexical scope.
213 bool dominates(const LexicalScope *S) const {
216 if (DFSIn < S->getDFSIn() && DFSOut > S->getDFSOut())
221 // Depth First Search support to walk and manipulate LexicalScope hierarchy.
222 unsigned getDFSOut() const { return DFSOut; }
223 void setDFSOut(unsigned O) { DFSOut = O; }
224 unsigned getDFSIn() const { return DFSIn; }
225 void setDFSIn(unsigned I) { DFSIn = I; }
227 /// dump - print lexical scope.
228 void dump(unsigned Indent = 0) const;
231 LexicalScope *Parent; // Parent to this scope.
232 AssertingVH<const MDNode> Desc; // Debug info descriptor.
233 AssertingVH<const MDNode> InlinedAtLocation; // Location at which this
235 bool AbstractScope; // Abstract Scope
236 SmallVector<LexicalScope *, 4> Children; // Scopes defined in scope.
237 // Contents not owned.
238 SmallVector<InsnRange, 4> Ranges;
240 const MachineInstr *LastInsn; // Last instruction of this scope.
241 const MachineInstr *FirstInsn; // First instruction of this scope.
242 unsigned DFSIn, DFSOut; // In & Out Depth use to determine
246 } // end llvm namespace