llvm-6502/include/llvm/CodeGen/LexicalScopes.h
2011-12-20 02:50:00 +00:00

250 lines
9.1 KiB
C++

//===- LexicalScopes.cpp - Collecting lexical scope info -*- C++ -*--------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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/Metadata.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/DebugLoc.h"
#include "llvm/Support/ValueHandle.h"
#include <utility>
namespace llvm {
class MachineInstr;
class MachineBasicBlock;
class MachineFunction;
class LexicalScope;
//===----------------------------------------------------------------------===//
/// InsnRange - This is used to track range of instructions with identical
/// lexical scope.
///
typedef std::pair<const MachineInstr *, const MachineInstr *> InsnRange;
//===----------------------------------------------------------------------===//
/// LexicalScopes - This class provides interface to collect and use lexical
/// scoping information from machine instruction.
///
class LexicalScopes {
public:
LexicalScopes() : MF(NULL), CurrentFnLexicalScope(NULL) { }
virtual ~LexicalScopes();
/// initialize - Scan machine function and constuct lexical scope nest.
virtual void initialize(const MachineFunction &);
/// releaseMemory - release memory.
virtual void releaseMemory();
/// empty - Return true if there is any lexical scope information available.
bool empty() { return CurrentFnLexicalScope == NULL; }
/// isCurrentFunctionScope - Return true if given lexical scope represents
/// current function.
bool isCurrentFunctionScope(const LexicalScope *LS) {
return LS == CurrentFnLexicalScope;
}
/// 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(DebugLoc DL,
SmallPtrSet<const MachineBasicBlock*, 4> &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(DebugLoc DL, MachineBasicBlock *MBB);
/// findLexicalScope - Find lexical scope, either regular or inlined, for the
/// given DebugLoc. Return NULL if not found.
LexicalScope *findLexicalScope(DebugLoc 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 MDNode *N) {
return AbstractScopeMap.lookup(N);
}
/// findInlinedScope - Find an inlined scope for the given DebugLoc or return
/// NULL.
LexicalScope *findInlinedScope(DebugLoc DL) {
return InlinedLexicalScopeMap.lookup(DL);
}
/// findLexicalScope - Find regular lexical scope or return NULL.
LexicalScope *findLexicalScope(const MDNode *N) {
return LexicalScopeMap.lookup(N);
}
/// dump - Print data structures to dbgs().
void dump();
private:
/// getOrCreateLexicalScope - Find lexical scope for the given DebugLoc. If
/// not available then create new lexical scope.
LexicalScope *getOrCreateLexicalScope(DebugLoc DL);
/// getOrCreateRegularScope - Find or create a regular lexical scope.
LexicalScope *getOrCreateRegularScope(MDNode *Scope);
/// getOrCreateInlinedScope - Find or create an inlined lexical scope.
LexicalScope *getOrCreateInlinedScope(MDNode *Scope, MDNode *InlinedAt);
/// getOrCreateAbstractScope - Find or create an abstract lexical scope.
LexicalScope *getOrCreateAbstractScope(const MDNode *N);
/// 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);
private:
const MachineFunction *MF;
/// LexicalScopeMap - Tracks the scopes in the current function. Owns the
/// contained LexicalScope*s.
DenseMap<const MDNode *, LexicalScope *> LexicalScopeMap;
/// InlinedLexicalScopeMap - Tracks inlined function scopes in current function.
DenseMap<DebugLoc, LexicalScope *> InlinedLexicalScopeMap;
/// AbstractScopeMap - These scopes are not included LexicalScopeMap.
/// AbstractScopes owns its LexicalScope*s.
DenseMap<const MDNode *, 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;
};
//===----------------------------------------------------------------------===//
/// LexicalScope - This class is used to track scope information.
///
class LexicalScope {
virtual void anchor();
public:
LexicalScope(LexicalScope *P, const MDNode *D, const MDNode *I, bool A)
: Parent(P), Desc(D), InlinedAtLocation(I), AbstractScope(A),
LastInsn(0), FirstInsn(0), DFSIn(0), DFSOut(0), IndentLevel(0) {
if (Parent)
Parent->addChild(this);
}
virtual ~LexicalScope() {}
// Accessors.
LexicalScope *getParent() const { return Parent; }
const MDNode *getDesc() const { return Desc; }
const MDNode *getInlinedAt() const { return InlinedAtLocation; }
const MDNode *getScopeNode() const { return Desc; }
bool isAbstractScope() const { return AbstractScope; }
SmallVector<LexicalScope *, 4> &getChildren() { return Children; }
SmallVector<InsnRange, 4> &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 = NULL) {
assert (LastInsn && "Last insn missing!");
Ranges.push_back(InsnRange(FirstInsn, LastInsn));
FirstInsn = NULL;
LastInsn = NULL;
// 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 dominsates 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() const;
private:
LexicalScope *Parent; // Parent to this scope.
AssertingVH<const MDNode> Desc; // Debug info descriptor.
AssertingVH<const MDNode> 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; // Last instruction of this scope.
const MachineInstr *FirstInsn; // First instruction of this scope.
unsigned DFSIn, DFSOut; // In & Out Depth use to determine
// scope nesting.
mutable unsigned IndentLevel; // Private state for dump()
};
} // end llvm namespace
#endif