| //===- LexicalScopes.cpp - Collecting lexical scope info --------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements LexicalScopes analysis. |
| // |
| // This pass collects lexical scope information and maps machine instructions |
| // to respective lexical scopes. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CODEGEN_LEXICALSCOPES_H |
| #define LLVM_CODEGEN_LEXICALSCOPES_H |
| |
| #include "llvm/ADT/ArrayRef.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/SmallPtrSet.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/IR/DebugInfoMetadata.h" |
| #include <cassert> |
| #include <unordered_map> |
| #include <utility> |
| |
| namespace llvm { |
| |
| class MachineBasicBlock; |
| class MachineFunction; |
| class MachineInstr; |
| class MDNode; |
| |
| //===----------------------------------------------------------------------===// |
| /// InsnRange - This is used to track range of instructions with identical |
| /// lexical scope. |
| /// |
| using InsnRange = std::pair<const MachineInstr *, const MachineInstr *>; |
| |
| //===----------------------------------------------------------------------===// |
| /// LexicalScope - This class is used to track scope information. |
| /// |
| class LexicalScope { |
| public: |
| LexicalScope(LexicalScope *P, const DILocalScope *D, const DILocation *I, |
| bool A) |
| : Parent(P), Desc(D), InlinedAtLocation(I), AbstractScope(A) { |
| assert(D); |
| assert(D->getSubprogram()->getUnit()->getEmissionKind() != |
| DICompileUnit::NoDebug && |
| "Don't build lexical scopes for non-debug locations"); |
| assert(D->isResolved() && "Expected resolved node"); |
| assert((!I || I->isResolved()) && "Expected resolved node"); |
| if (Parent) |
| Parent->addChild(this); |
| } |
| |
| // Accessors. |
| LexicalScope *getParent() const { return Parent; } |
| const MDNode *getDesc() const { return Desc; } |
| const DILocation *getInlinedAt() const { return InlinedAtLocation; } |
| const DILocalScope *getScopeNode() const { return Desc; } |
| bool isAbstractScope() const { return AbstractScope; } |
| SmallVectorImpl<LexicalScope *> &getChildren() { return Children; } |
| SmallVectorImpl<InsnRange> &getRanges() { return Ranges; } |
| |
| /// addChild - Add a child scope. |
| void addChild(LexicalScope *S) { Children.push_back(S); } |
| |
| /// openInsnRange - This scope covers instruction range starting from MI. |
| void openInsnRange(const MachineInstr *MI) { |
| if (!FirstInsn) |
| FirstInsn = MI; |
| |
| if (Parent) |
| Parent->openInsnRange(MI); |
| } |
| |
| /// extendInsnRange - Extend the current instruction range covered by |
| /// this scope. |
| void extendInsnRange(const MachineInstr *MI) { |
| assert(FirstInsn && "MI Range is not open!"); |
| LastInsn = MI; |
| if (Parent) |
| Parent->extendInsnRange(MI); |
| } |
| |
| /// closeInsnRange - Create a range based on FirstInsn and LastInsn collected |
| /// until now. This is used when a new scope is encountered while walking |
| /// machine instructions. |
| void closeInsnRange(LexicalScope *NewScope = nullptr) { |
| assert(LastInsn && "Last insn missing!"); |
| Ranges.push_back(InsnRange(FirstInsn, LastInsn)); |
| FirstInsn = nullptr; |
| LastInsn = nullptr; |
| // If Parent dominates NewScope then do not close Parent's instruction |
| // range. |
| if (Parent && (!NewScope || !Parent->dominates(NewScope))) |
| Parent->closeInsnRange(NewScope); |
| } |
| |
| /// dominates - Return true if current scope dominates given lexical scope. |
| bool dominates(const LexicalScope *S) const { |
| if (S == this) |
| return true; |
| if (DFSIn < S->getDFSIn() && DFSOut > S->getDFSOut()) |
| return true; |
| return false; |
| } |
| |
| // Depth First Search support to walk and manipulate LexicalScope hierarchy. |
| unsigned getDFSOut() const { return DFSOut; } |
| void setDFSOut(unsigned O) { DFSOut = O; } |
| unsigned getDFSIn() const { return DFSIn; } |
| void setDFSIn(unsigned I) { DFSIn = I; } |
| |
| /// dump - print lexical scope. |
| void dump(unsigned Indent = 0) const; |
| |
| private: |
| LexicalScope *Parent; // Parent to this scope. |
| const DILocalScope *Desc; // Debug info descriptor. |
| const DILocation *InlinedAtLocation; // Location at which this |
| // scope is inlined. |
| bool AbstractScope; // Abstract Scope |
| SmallVector<LexicalScope *, 4> Children; // Scopes defined in scope. |
| // Contents not owned. |
| SmallVector<InsnRange, 4> Ranges; |
| |
| const MachineInstr *LastInsn = nullptr; // Last instruction of this scope. |
| const MachineInstr *FirstInsn = nullptr; // First instruction of this scope. |
| unsigned DFSIn = 0; // In & Out Depth use to determine scope nesting. |
| unsigned DFSOut = 0; |
| }; |
| |
| //===----------------------------------------------------------------------===// |
| /// LexicalScopes - This class provides interface to collect and use lexical |
| /// scoping information from machine instruction. |
| /// |
| class LexicalScopes { |
| public: |
| LexicalScopes() = default; |
| |
| /// initialize - Scan machine function and constuct lexical scope nest, resets |
| /// the instance if necessary. |
| void initialize(const MachineFunction &); |
| |
| /// releaseMemory - release memory. |
| void reset(); |
| |
| /// empty - Return true if there is any lexical scope information available. |
| bool empty() { return CurrentFnLexicalScope == nullptr; } |
| |
| /// getCurrentFunctionScope - Return lexical scope for the current function. |
| LexicalScope *getCurrentFunctionScope() const { |
| return CurrentFnLexicalScope; |
| } |
| |
| /// getMachineBasicBlocks - Populate given set using machine basic blocks |
| /// which have machine instructions that belong to lexical scope identified by |
| /// DebugLoc. |
| void getMachineBasicBlocks(const DILocation *DL, |
| SmallPtrSetImpl<const MachineBasicBlock *> &MBBs); |
| |
| /// dominates - Return true if DebugLoc's lexical scope dominates at least one |
| /// machine instruction's lexical scope in a given machine basic block. |
| bool dominates(const DILocation *DL, MachineBasicBlock *MBB); |
| |
| /// findLexicalScope - Find lexical scope, either regular or inlined, for the |
| /// given DebugLoc. Return NULL if not found. |
| LexicalScope *findLexicalScope(const DILocation *DL); |
| |
| /// getAbstractScopesList - Return a reference to list of abstract scopes. |
| ArrayRef<LexicalScope *> getAbstractScopesList() const { |
| return AbstractScopesList; |
| } |
| |
| /// findAbstractScope - Find an abstract scope or return null. |
| LexicalScope *findAbstractScope(const DILocalScope *N) { |
| auto I = AbstractScopeMap.find(N); |
| return I != AbstractScopeMap.end() ? &I->second : nullptr; |
| } |
| |
| /// findInlinedScope - Find an inlined scope for the given scope/inlined-at. |
| LexicalScope *findInlinedScope(const DILocalScope *N, const DILocation *IA) { |
| auto I = InlinedLexicalScopeMap.find(std::make_pair(N, IA)); |
| return I != InlinedLexicalScopeMap.end() ? &I->second : nullptr; |
| } |
| |
| /// findLexicalScope - Find regular lexical scope or return null. |
| LexicalScope *findLexicalScope(const DILocalScope *N) { |
| auto I = LexicalScopeMap.find(N); |
| return I != LexicalScopeMap.end() ? &I->second : nullptr; |
| } |
| |
| /// dump - Print data structures to dbgs(). |
| void dump() const; |
| |
| /// getOrCreateAbstractScope - Find or create an abstract lexical scope. |
| LexicalScope *getOrCreateAbstractScope(const DILocalScope *Scope); |
| |
| private: |
| /// getOrCreateLexicalScope - Find lexical scope for the given Scope/IA. If |
| /// not available then create new lexical scope. |
| LexicalScope *getOrCreateLexicalScope(const DILocalScope *Scope, |
| const DILocation *IA = nullptr); |
| LexicalScope *getOrCreateLexicalScope(const DILocation *DL) { |
| return DL ? getOrCreateLexicalScope(DL->getScope(), DL->getInlinedAt()) |
| : nullptr; |
| } |
| |
| /// getOrCreateRegularScope - Find or create a regular lexical scope. |
| LexicalScope *getOrCreateRegularScope(const DILocalScope *Scope); |
| |
| /// getOrCreateInlinedScope - Find or create an inlined lexical scope. |
| LexicalScope *getOrCreateInlinedScope(const DILocalScope *Scope, |
| const DILocation *InlinedAt); |
| |
| /// extractLexicalScopes - Extract instruction ranges for each lexical scopes |
| /// for the given machine function. |
| void extractLexicalScopes(SmallVectorImpl<InsnRange> &MIRanges, |
| DenseMap<const MachineInstr *, LexicalScope *> &M); |
| void constructScopeNest(LexicalScope *Scope); |
| void |
| assignInstructionRanges(SmallVectorImpl<InsnRange> &MIRanges, |
| DenseMap<const MachineInstr *, LexicalScope *> &M); |
| |
| const MachineFunction *MF = nullptr; |
| |
| /// LexicalScopeMap - Tracks the scopes in the current function. |
| // Use an unordered_map to ensure value pointer validity over insertion. |
| std::unordered_map<const DILocalScope *, LexicalScope> LexicalScopeMap; |
| |
| /// InlinedLexicalScopeMap - Tracks inlined function scopes in current |
| /// function. |
| std::unordered_map<std::pair<const DILocalScope *, const DILocation *>, |
| LexicalScope, |
| pair_hash<const DILocalScope *, const DILocation *>> |
| InlinedLexicalScopeMap; |
| |
| /// AbstractScopeMap - These scopes are not included LexicalScopeMap. |
| // Use an unordered_map to ensure value pointer validity over insertion. |
| std::unordered_map<const DILocalScope *, LexicalScope> AbstractScopeMap; |
| |
| /// AbstractScopesList - Tracks abstract scopes constructed while processing |
| /// a function. |
| SmallVector<LexicalScope *, 4> AbstractScopesList; |
| |
| /// CurrentFnLexicalScope - Top level scope for the current function. |
| /// |
| LexicalScope *CurrentFnLexicalScope = nullptr; |
| }; |
| |
| } // end namespace llvm |
| |
| #endif // LLVM_CODEGEN_LEXICALSCOPES_H |