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//===--- CFG.h - Classes for representing and building CFGs------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the CFG and CFGBuilder classes for representing and
// building Control-Flow Graphs (CFGs) from ASTs.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_CFG_H
#define LLVM_CLANG_CFG_H
#include "clang/AST/Stmt.h"
#include "clang/Analysis/Support/BumpVector.h"
#include "clang/Basic/SourceLocation.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/GraphTraits.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/raw_ostream.h"
#include <bitset>
#include <cassert>
#include <iterator>
#include <memory>
namespace clang {
class CXXDestructorDecl;
class Decl;
class Stmt;
class Expr;
class FieldDecl;
class VarDecl;
class CXXCtorInitializer;
class CXXBaseSpecifier;
class CXXBindTemporaryExpr;
class CFG;
class PrinterHelper;
class LangOptions;
class ASTContext;
class CXXRecordDecl;
class CXXDeleteExpr;
class CXXNewExpr;
/// CFGElement - Represents a top-level expression in a basic block.
class CFGElement {
public:
enum Kind {
// main kind
Statement,
Initializer,
NewAllocator,
// dtor kind
AutomaticObjectDtor,
DeleteDtor,
BaseDtor,
MemberDtor,
TemporaryDtor,
DTOR_BEGIN = AutomaticObjectDtor,
DTOR_END = TemporaryDtor
};
protected:
// The int bits are used to mark the kind.
llvm::PointerIntPair<void *, 2> Data1;
llvm::PointerIntPair<void *, 2> Data2;
CFGElement(Kind kind, const void *Ptr1, const void *Ptr2 = 0)
: Data1(const_cast<void*>(Ptr1), ((unsigned) kind) & 0x3),
Data2(const_cast<void*>(Ptr2), (((unsigned) kind) >> 2) & 0x3) {
assert(getKind() == kind);
}
CFGElement() {}
public:
/// \brief Convert to the specified CFGElement type, asserting that this
/// CFGElement is of the desired type.
template<typename T>
T castAs() const {
assert(T::isKind(*this));
T t;
CFGElement& e = t;
e = *this;
return t;
}
/// \brief Convert to the specified CFGElement type, returning None if this
/// CFGElement is not of the desired type.
template<typename T>
Optional<T> getAs() const {
if (!T::isKind(*this))
return None;
T t;
CFGElement& e = t;
e = *this;
return t;
}
Kind getKind() const {
unsigned x = Data2.getInt();
x <<= 2;
x |= Data1.getInt();
return (Kind) x;
}
};
class CFGStmt : public CFGElement {
public:
CFGStmt(Stmt *S) : CFGElement(Statement, S) {}
const Stmt *getStmt() const {
return static_cast<const Stmt *>(Data1.getPointer());
}
private:
friend class CFGElement;
CFGStmt() {}
static bool isKind(const CFGElement &E) {
return E.getKind() == Statement;
}
};
/// CFGInitializer - Represents C++ base or member initializer from
/// constructor's initialization list.
class CFGInitializer : public CFGElement {
public:
CFGInitializer(CXXCtorInitializer *initializer)
: CFGElement(Initializer, initializer) {}
CXXCtorInitializer* getInitializer() const {
return static_cast<CXXCtorInitializer*>(Data1.getPointer());
}
private:
friend class CFGElement;
CFGInitializer() {}
static bool isKind(const CFGElement &E) {
return E.getKind() == Initializer;
}
};
/// CFGNewAllocator - Represents C++ allocator call.
class CFGNewAllocator : public CFGElement {
public:
explicit CFGNewAllocator(const CXXNewExpr *S)
: CFGElement(NewAllocator, S) {}
// Get the new expression.
const CXXNewExpr *getAllocatorExpr() const {
return static_cast<CXXNewExpr *>(Data1.getPointer());
}
private:
friend class CFGElement;
CFGNewAllocator() {}
static bool isKind(const CFGElement &elem) {
return elem.getKind() == NewAllocator;
}
};
/// CFGImplicitDtor - Represents C++ object destructor implicitly generated
/// by compiler on various occasions.
class CFGImplicitDtor : public CFGElement {
protected:
CFGImplicitDtor() {}
CFGImplicitDtor(Kind kind, const void *data1, const void *data2 = 0)
: CFGElement(kind, data1, data2) {
assert(kind >= DTOR_BEGIN && kind <= DTOR_END);
}
public:
const CXXDestructorDecl *getDestructorDecl(ASTContext &astContext) const;
bool isNoReturn(ASTContext &astContext) const;
private:
friend class CFGElement;
static bool isKind(const CFGElement &E) {
Kind kind = E.getKind();
return kind >= DTOR_BEGIN && kind <= DTOR_END;
}
};
/// CFGAutomaticObjDtor - Represents C++ object destructor implicitly generated
/// for automatic object or temporary bound to const reference at the point
/// of leaving its local scope.
class CFGAutomaticObjDtor: public CFGImplicitDtor {
public:
CFGAutomaticObjDtor(const VarDecl *var, const Stmt *stmt)
: CFGImplicitDtor(AutomaticObjectDtor, var, stmt) {}
const VarDecl *getVarDecl() const {
return static_cast<VarDecl*>(Data1.getPointer());
}
// Get statement end of which triggered the destructor call.
const Stmt *getTriggerStmt() const {
return static_cast<Stmt*>(Data2.getPointer());
}
private:
friend class CFGElement;
CFGAutomaticObjDtor() {}
static bool isKind(const CFGElement &elem) {
return elem.getKind() == AutomaticObjectDtor;
}
};
/// CFGDeleteDtor - Represents C++ object destructor generated
/// from a call to delete.
class CFGDeleteDtor : public CFGImplicitDtor {
public:
CFGDeleteDtor(const CXXRecordDecl *RD, const CXXDeleteExpr *DE)
: CFGImplicitDtor(DeleteDtor, RD, DE) {}
const CXXRecordDecl *getCXXRecordDecl() const {
return static_cast<CXXRecordDecl*>(Data1.getPointer());
}
// Get Delete expression which triggered the destructor call.
const CXXDeleteExpr *getDeleteExpr() const {
return static_cast<CXXDeleteExpr *>(Data2.getPointer());
}
private:
friend class CFGElement;
CFGDeleteDtor() {}
static bool isKind(const CFGElement &elem) {
return elem.getKind() == DeleteDtor;
}
};
/// CFGBaseDtor - Represents C++ object destructor implicitly generated for
/// base object in destructor.
class CFGBaseDtor : public CFGImplicitDtor {
public:
CFGBaseDtor(const CXXBaseSpecifier *base)
: CFGImplicitDtor(BaseDtor, base) {}
const CXXBaseSpecifier *getBaseSpecifier() const {
return static_cast<const CXXBaseSpecifier*>(Data1.getPointer());
}
private:
friend class CFGElement;
CFGBaseDtor() {}
static bool isKind(const CFGElement &E) {
return E.getKind() == BaseDtor;
}
};
/// CFGMemberDtor - Represents C++ object destructor implicitly generated for
/// member object in destructor.
class CFGMemberDtor : public CFGImplicitDtor {
public:
CFGMemberDtor(const FieldDecl *field)
: CFGImplicitDtor(MemberDtor, field, 0) {}
const FieldDecl *getFieldDecl() const {
return static_cast<const FieldDecl*>(Data1.getPointer());
}
private:
friend class CFGElement;
CFGMemberDtor() {}
static bool isKind(const CFGElement &E) {
return E.getKind() == MemberDtor;
}
};
/// CFGTemporaryDtor - Represents C++ object destructor implicitly generated
/// at the end of full expression for temporary object.
class CFGTemporaryDtor : public CFGImplicitDtor {
public:
CFGTemporaryDtor(CXXBindTemporaryExpr *expr)
: CFGImplicitDtor(TemporaryDtor, expr, 0) {}
const CXXBindTemporaryExpr *getBindTemporaryExpr() const {
return static_cast<const CXXBindTemporaryExpr *>(Data1.getPointer());
}
private:
friend class CFGElement;
CFGTemporaryDtor() {}
static bool isKind(const CFGElement &E) {
return E.getKind() == TemporaryDtor;
}
};
/// CFGTerminator - Represents CFGBlock terminator statement.
///
/// TemporaryDtorsBranch bit is set to true if the terminator marks a branch
/// in control flow of destructors of temporaries. In this case terminator
/// statement is the same statement that branches control flow in evaluation
/// of matching full expression.
class CFGTerminator {
llvm::PointerIntPair<Stmt *, 1> Data;
public:
CFGTerminator() {}
CFGTerminator(Stmt *S, bool TemporaryDtorsBranch = false)
: Data(S, TemporaryDtorsBranch) {}
Stmt *getStmt() { return Data.getPointer(); }
const Stmt *getStmt() const { return Data.getPointer(); }
bool isTemporaryDtorsBranch() const { return Data.getInt(); }
operator Stmt *() { return getStmt(); }
operator const Stmt *() const { return getStmt(); }
Stmt *operator->() { return getStmt(); }
const Stmt *operator->() const { return getStmt(); }
Stmt &operator*() { return *getStmt(); }
const Stmt &operator*() const { return *getStmt(); }
LLVM_EXPLICIT operator bool() const { return getStmt(); }
};
/// CFGBlock - Represents a single basic block in a source-level CFG.
/// It consists of:
///
/// (1) A set of statements/expressions (which may contain subexpressions).
/// (2) A "terminator" statement (not in the set of statements).
/// (3) A list of successors and predecessors.
///
/// Terminator: The terminator represents the type of control-flow that occurs
/// at the end of the basic block. The terminator is a Stmt* referring to an
/// AST node that has control-flow: if-statements, breaks, loops, etc.
/// If the control-flow is conditional, the condition expression will appear
/// within the set of statements in the block (usually the last statement).
///
/// Predecessors: the order in the set of predecessors is arbitrary.
///
/// Successors: the order in the set of successors is NOT arbitrary. We
/// currently have the following orderings based on the terminator:
///
/// Terminator Successor Ordering
/// -----------------------------------------------------
/// if Then Block; Else Block
/// ? operator LHS expression; RHS expression
/// &&, || expression that uses result of && or ||, RHS
///
/// But note that any of that may be NULL in case of optimized-out edges.
///
class CFGBlock {
class ElementList {
typedef BumpVector<CFGElement> ImplTy;
ImplTy Impl;
public:
ElementList(BumpVectorContext &C) : Impl(C, 4) {}
typedef std::reverse_iterator<ImplTy::iterator> iterator;
typedef std::reverse_iterator<ImplTy::const_iterator> const_iterator;
typedef ImplTy::iterator reverse_iterator;
typedef ImplTy::const_iterator const_reverse_iterator;
typedef ImplTy::const_reference const_reference;
void push_back(CFGElement e, BumpVectorContext &C) { Impl.push_back(e, C); }
reverse_iterator insert(reverse_iterator I, size_t Cnt, CFGElement E,
BumpVectorContext &C) {
return Impl.insert(I, Cnt, E, C);
}
const_reference front() const { return Impl.back(); }
const_reference back() const { return Impl.front(); }
iterator begin() { return Impl.rbegin(); }
iterator end() { return Impl.rend(); }
const_iterator begin() const { return Impl.rbegin(); }
const_iterator end() const { return Impl.rend(); }
reverse_iterator rbegin() { return Impl.begin(); }
reverse_iterator rend() { return Impl.end(); }
const_reverse_iterator rbegin() const { return Impl.begin(); }
const_reverse_iterator rend() const { return Impl.end(); }
CFGElement operator[](size_t i) const {
assert(i < Impl.size());
return Impl[Impl.size() - 1 - i];
}
size_t size() const { return Impl.size(); }
bool empty() const { return Impl.empty(); }
};
/// Stmts - The set of statements in the basic block.
ElementList Elements;
/// Label - An (optional) label that prefixes the executable
/// statements in the block. When this variable is non-NULL, it is
/// either an instance of LabelStmt, SwitchCase or CXXCatchStmt.
Stmt *Label;
/// Terminator - The terminator for a basic block that
/// indicates the type of control-flow that occurs between a block
/// and its successors.
CFGTerminator Terminator;
/// LoopTarget - Some blocks are used to represent the "loop edge" to
/// the start of a loop from within the loop body. This Stmt* will be
/// refer to the loop statement for such blocks (and be null otherwise).
const Stmt *LoopTarget;
/// BlockID - A numerical ID assigned to a CFGBlock during construction
/// of the CFG.
unsigned BlockID;
public:
/// This class represents a potential adjacent block in the CFG. It encodes
/// whether or not the block is actually reachable, or can be proved to be
/// trivially unreachable. For some cases it allows one to encode scenarios
/// where a block was substituted because the original (now alternate) block
/// is unreachable.
class AdjacentBlock {
enum Kind {
AB_Normal,
AB_Unreachable,
AB_Alternate
};
CFGBlock *ReachableBlock;
llvm::PointerIntPair<CFGBlock*, 2> UnreachableBlock;
public:
/// Construct an AdjacentBlock with a possibly unreachable block.
AdjacentBlock(CFGBlock *B, bool IsReachable);
/// Construct an AdjacentBlock with a reachable block and an alternate
/// unreachable block.
AdjacentBlock(CFGBlock *B, CFGBlock *AlternateBlock);
/// Get the reachable block, if one exists.
CFGBlock *getReachableBlock() const {
return ReachableBlock;
}
/// Get the potentially unreachable block.
CFGBlock *getPossiblyUnreachableBlock() const {
return UnreachableBlock.getPointer();
}
/// Provide an implicit conversion to CFGBlock* so that
/// AdjacentBlock can be substituted for CFGBlock*.
operator CFGBlock*() const {
return getReachableBlock();
}
CFGBlock& operator *() const {
return *getReachableBlock();
}
CFGBlock* operator ->() const {
return getReachableBlock();
}
bool isReachable() const {
Kind K = (Kind) UnreachableBlock.getInt();
return K == AB_Normal || K == AB_Alternate;
}
};
private:
/// Predecessors/Successors - Keep track of the predecessor / successor
/// CFG blocks.
typedef BumpVector<AdjacentBlock> AdjacentBlocks;
AdjacentBlocks Preds;
AdjacentBlocks Succs;
/// NoReturn - This bit is set when the basic block contains a function call
/// or implicit destructor that is attributed as 'noreturn'. In that case,
/// control cannot technically ever proceed past this block. All such blocks
/// will have a single immediate successor: the exit block. This allows them
/// to be easily reached from the exit block and using this bit quickly
/// recognized without scanning the contents of the block.
///
/// Optimization Note: This bit could be profitably folded with Terminator's
/// storage if the memory usage of CFGBlock becomes an issue.
unsigned HasNoReturnElement : 1;
/// Parent - The parent CFG that owns this CFGBlock.
CFG *Parent;
public:
explicit CFGBlock(unsigned blockid, BumpVectorContext &C, CFG *parent)
: Elements(C), Label(NULL), Terminator(NULL), LoopTarget(NULL),
BlockID(blockid), Preds(C, 1), Succs(C, 1), HasNoReturnElement(false),
Parent(parent) {}
~CFGBlock() {}
// Statement iterators
typedef ElementList::iterator iterator;
typedef ElementList::const_iterator const_iterator;
typedef ElementList::reverse_iterator reverse_iterator;
typedef ElementList::const_reverse_iterator const_reverse_iterator;
CFGElement front() const { return Elements.front(); }
CFGElement back() const { return Elements.back(); }
iterator begin() { return Elements.begin(); }
iterator end() { return Elements.end(); }
const_iterator begin() const { return Elements.begin(); }
const_iterator end() const { return Elements.end(); }
reverse_iterator rbegin() { return Elements.rbegin(); }
reverse_iterator rend() { return Elements.rend(); }
const_reverse_iterator rbegin() const { return Elements.rbegin(); }
const_reverse_iterator rend() const { return Elements.rend(); }
unsigned size() const { return Elements.size(); }
bool empty() const { return Elements.empty(); }
CFGElement operator[](size_t i) const { return Elements[i]; }
// CFG iterators
typedef AdjacentBlocks::iterator pred_iterator;
typedef AdjacentBlocks::const_iterator const_pred_iterator;
typedef AdjacentBlocks::reverse_iterator pred_reverse_iterator;
typedef AdjacentBlocks::const_reverse_iterator const_pred_reverse_iterator;
typedef AdjacentBlocks::iterator succ_iterator;
typedef AdjacentBlocks::const_iterator const_succ_iterator;
typedef AdjacentBlocks::reverse_iterator succ_reverse_iterator;
typedef AdjacentBlocks::const_reverse_iterator const_succ_reverse_iterator;
pred_iterator pred_begin() { return Preds.begin(); }
pred_iterator pred_end() { return Preds.end(); }
const_pred_iterator pred_begin() const { return Preds.begin(); }
const_pred_iterator pred_end() const { return Preds.end(); }
pred_reverse_iterator pred_rbegin() { return Preds.rbegin(); }
pred_reverse_iterator pred_rend() { return Preds.rend(); }
const_pred_reverse_iterator pred_rbegin() const { return Preds.rbegin(); }
const_pred_reverse_iterator pred_rend() const { return Preds.rend(); }
succ_iterator succ_begin() { return Succs.begin(); }
succ_iterator succ_end() { return Succs.end(); }
const_succ_iterator succ_begin() const { return Succs.begin(); }
const_succ_iterator succ_end() const { return Succs.end(); }
succ_reverse_iterator succ_rbegin() { return Succs.rbegin(); }
succ_reverse_iterator succ_rend() { return Succs.rend(); }
const_succ_reverse_iterator succ_rbegin() const { return Succs.rbegin(); }
const_succ_reverse_iterator succ_rend() const { return Succs.rend(); }
unsigned succ_size() const { return Succs.size(); }
bool succ_empty() const { return Succs.empty(); }
unsigned pred_size() const { return Preds.size(); }
bool pred_empty() const { return Preds.empty(); }
class FilterOptions {
public:
FilterOptions() {
IgnoreNullPredecessors = 1;
IgnoreDefaultsWithCoveredEnums = 0;
}
unsigned IgnoreNullPredecessors : 1;
unsigned IgnoreDefaultsWithCoveredEnums : 1;
};
static bool FilterEdge(const FilterOptions &F, const CFGBlock *Src,
const CFGBlock *Dst);
template <typename IMPL, bool IsPred>
class FilteredCFGBlockIterator {
private:
IMPL I, E;
const FilterOptions F;
const CFGBlock *From;
public:
explicit FilteredCFGBlockIterator(const IMPL &i, const IMPL &e,
const CFGBlock *from,
const FilterOptions &f)
: I(i), E(e), F(f), From(from) {
while (hasMore() && Filter(*I))
++I;
}
bool hasMore() const { return I != E; }
FilteredCFGBlockIterator &operator++() {
do { ++I; } while (hasMore() && Filter(*I));
return *this;
}
const CFGBlock *operator*() const { return *I; }
private:
bool Filter(const CFGBlock *To) {
return IsPred ? FilterEdge(F, To, From) : FilterEdge(F, From, To);
}
};
typedef FilteredCFGBlockIterator<const_pred_iterator, true>
filtered_pred_iterator;
typedef FilteredCFGBlockIterator<const_succ_iterator, false>
filtered_succ_iterator;
filtered_pred_iterator filtered_pred_start_end(const FilterOptions &f) const {
return filtered_pred_iterator(pred_begin(), pred_end(), this, f);
}
filtered_succ_iterator filtered_succ_start_end(const FilterOptions &f) const {
return filtered_succ_iterator(succ_begin(), succ_end(), this, f);
}
// Manipulation of block contents
void setTerminator(CFGTerminator Term) { Terminator = Term; }
void setLabel(Stmt *Statement) { Label = Statement; }
void setLoopTarget(const Stmt *loopTarget) { LoopTarget = loopTarget; }
void setHasNoReturnElement() { HasNoReturnElement = true; }
CFGTerminator getTerminator() { return Terminator; }
const CFGTerminator getTerminator() const { return Terminator; }
Stmt *getTerminatorCondition(bool StripParens = true);
const Stmt *getTerminatorCondition(bool StripParens = true) const {
return const_cast<CFGBlock*>(this)->getTerminatorCondition(StripParens);
}
const Stmt *getLoopTarget() const { return LoopTarget; }
Stmt *getLabel() { return Label; }
const Stmt *getLabel() const { return Label; }
bool hasNoReturnElement() const { return HasNoReturnElement; }
unsigned getBlockID() const { return BlockID; }
CFG *getParent() const { return Parent; }
void dump(const CFG *cfg, const LangOptions &LO, bool ShowColors = false) const;
void print(raw_ostream &OS, const CFG* cfg, const LangOptions &LO,
bool ShowColors) const;
void printTerminator(raw_ostream &OS, const LangOptions &LO) const;
void printAsOperand(raw_ostream &OS, bool /*PrintType*/) {
OS << "BB#" << getBlockID();
}
/// Adds a (potentially unreachable) successor block to the current block.
void addSuccessor(AdjacentBlock Succ, BumpVectorContext &C);
void appendStmt(Stmt *statement, BumpVectorContext &C) {
Elements.push_back(CFGStmt(statement), C);
}
void appendInitializer(CXXCtorInitializer *initializer,
BumpVectorContext &C) {
Elements.push_back(CFGInitializer(initializer), C);
}
void appendNewAllocator(CXXNewExpr *NE,
BumpVectorContext &C) {
Elements.push_back(CFGNewAllocator(NE), C);
}
void appendBaseDtor(const CXXBaseSpecifier *BS, BumpVectorContext &C) {
Elements.push_back(CFGBaseDtor(BS), C);
}
void appendMemberDtor(FieldDecl *FD, BumpVectorContext &C) {
Elements.push_back(CFGMemberDtor(FD), C);
}
void appendTemporaryDtor(CXXBindTemporaryExpr *E, BumpVectorContext &C) {
Elements.push_back(CFGTemporaryDtor(E), C);
}
void appendAutomaticObjDtor(VarDecl *VD, Stmt *S, BumpVectorContext &C) {
Elements.push_back(CFGAutomaticObjDtor(VD, S), C);
}
void appendDeleteDtor(CXXRecordDecl *RD, CXXDeleteExpr *DE, BumpVectorContext &C) {
Elements.push_back(CFGDeleteDtor(RD, DE), C);
}
// Destructors must be inserted in reversed order. So insertion is in two
// steps. First we prepare space for some number of elements, then we insert
// the elements beginning at the last position in prepared space.
iterator beginAutomaticObjDtorsInsert(iterator I, size_t Cnt,
BumpVectorContext &C) {
return iterator(Elements.insert(I.base(), Cnt, CFGAutomaticObjDtor(0, 0), C));
}
iterator insertAutomaticObjDtor(iterator I, VarDecl *VD, Stmt *S) {
*I = CFGAutomaticObjDtor(VD, S);
return ++I;
}
};
/// CFG - Represents a source-level, intra-procedural CFG that represents the
/// control-flow of a Stmt. The Stmt can represent an entire function body,
/// or a single expression. A CFG will always contain one empty block that
/// represents the Exit point of the CFG. A CFG will also contain a designated
/// Entry block. The CFG solely represents control-flow; it consists of
/// CFGBlocks which are simply containers of Stmt*'s in the AST the CFG
/// was constructed from.
class CFG {
public:
//===--------------------------------------------------------------------===//
// CFG Construction & Manipulation.
//===--------------------------------------------------------------------===//
class BuildOptions {
std::bitset<Stmt::lastStmtConstant> alwaysAddMask;
public:
typedef llvm::DenseMap<const Stmt *, const CFGBlock*> ForcedBlkExprs;
ForcedBlkExprs **forcedBlkExprs;
bool PruneTriviallyFalseEdges;
bool AddEHEdges;
bool AddInitializers;
bool AddImplicitDtors;
bool AddTemporaryDtors;
bool AddStaticInitBranches;
bool AddCXXNewAllocator;
bool alwaysAdd(const Stmt *stmt) const {
return alwaysAddMask[stmt->getStmtClass()];
}
BuildOptions &setAlwaysAdd(Stmt::StmtClass stmtClass, bool val = true) {
alwaysAddMask[stmtClass] = val;
return *this;
}
BuildOptions &setAllAlwaysAdd() {
alwaysAddMask.set();
return *this;
}
BuildOptions()
: forcedBlkExprs(0), PruneTriviallyFalseEdges(true)
,AddEHEdges(false)
,AddInitializers(false)
,AddImplicitDtors(false)
,AddTemporaryDtors(false)
,AddStaticInitBranches(false)
,AddCXXNewAllocator(false) {}
};
/// \brief Provides a custom implementation of the iterator class to have the
/// same interface as Function::iterator - iterator returns CFGBlock
/// (not a pointer to CFGBlock).
class graph_iterator {
public:
typedef const CFGBlock value_type;
typedef value_type& reference;
typedef value_type* pointer;
typedef BumpVector<CFGBlock*>::iterator ImplTy;
graph_iterator(const ImplTy &i) : I(i) {}
bool operator==(const graph_iterator &X) const { return I == X.I; }
bool operator!=(const graph_iterator &X) const { return I != X.I; }
reference operator*() const { return **I; }
pointer operator->() const { return *I; }
operator CFGBlock* () { return *I; }
graph_iterator &operator++() { ++I; return *this; }
graph_iterator &operator--() { --I; return *this; }
private:
ImplTy I;
};
class const_graph_iterator {
public:
typedef const CFGBlock value_type;
typedef value_type& reference;
typedef value_type* pointer;
typedef BumpVector<CFGBlock*>::const_iterator ImplTy;
const_graph_iterator(const ImplTy &i) : I(i) {}
bool operator==(const const_graph_iterator &X) const { return I == X.I; }
bool operator!=(const const_graph_iterator &X) const { return I != X.I; }
reference operator*() const { return **I; }
pointer operator->() const { return *I; }
operator CFGBlock* () const { return *I; }
const_graph_iterator &operator++() { ++I; return *this; }
const_graph_iterator &operator--() { --I; return *this; }
private:
ImplTy I;
};
/// buildCFG - Builds a CFG from an AST. The responsibility to free the
/// constructed CFG belongs to the caller.
static CFG* buildCFG(const Decl *D, Stmt *AST, ASTContext *C,
const BuildOptions &BO);
/// createBlock - Create a new block in the CFG. The CFG owns the block;
/// the caller should not directly free it.
CFGBlock *createBlock();
/// setEntry - Set the entry block of the CFG. This is typically used
/// only during CFG construction. Most CFG clients expect that the
/// entry block has no predecessors and contains no statements.
void setEntry(CFGBlock *B) { Entry = B; }
/// setIndirectGotoBlock - Set the block used for indirect goto jumps.
/// This is typically used only during CFG construction.
void setIndirectGotoBlock(CFGBlock *B) { IndirectGotoBlock = B; }
//===--------------------------------------------------------------------===//
// Block Iterators
//===--------------------------------------------------------------------===//
typedef BumpVector<CFGBlock*> CFGBlockListTy;
typedef CFGBlockListTy::iterator iterator;
typedef CFGBlockListTy::const_iterator const_iterator;
typedef std::reverse_iterator<iterator> reverse_iterator;
typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
CFGBlock & front() { return *Blocks.front(); }
CFGBlock & back() { return *Blocks.back(); }
iterator begin() { return Blocks.begin(); }
iterator end() { return Blocks.end(); }
const_iterator begin() const { return Blocks.begin(); }
const_iterator end() const { return Blocks.end(); }
graph_iterator nodes_begin() { return graph_iterator(Blocks.begin()); }
graph_iterator nodes_end() { return graph_iterator(Blocks.end()); }
const_graph_iterator nodes_begin() const {
return const_graph_iterator(Blocks.begin());
}
const_graph_iterator nodes_end() const {
return const_graph_iterator(Blocks.end());
}
reverse_iterator rbegin() { return Blocks.rbegin(); }
reverse_iterator rend() { return Blocks.rend(); }
const_reverse_iterator rbegin() const { return Blocks.rbegin(); }
const_reverse_iterator rend() const { return Blocks.rend(); }
CFGBlock & getEntry() { return *Entry; }
const CFGBlock & getEntry() const { return *Entry; }
CFGBlock & getExit() { return *Exit; }
const CFGBlock & getExit() const { return *Exit; }
CFGBlock * getIndirectGotoBlock() { return IndirectGotoBlock; }
const CFGBlock * getIndirectGotoBlock() const { return IndirectGotoBlock; }
typedef std::vector<const CFGBlock*>::const_iterator try_block_iterator;
try_block_iterator try_blocks_begin() const {
return TryDispatchBlocks.begin();
}
try_block_iterator try_blocks_end() const {
return TryDispatchBlocks.end();
}
void addTryDispatchBlock(const CFGBlock *block) {
TryDispatchBlocks.push_back(block);
}
/// Records a synthetic DeclStmt and the DeclStmt it was constructed from.
///
/// The CFG uses synthetic DeclStmts when a single AST DeclStmt contains
/// multiple decls.
void addSyntheticDeclStmt(const DeclStmt *Synthetic,
const DeclStmt *Source) {
assert(Synthetic->isSingleDecl() && "Can handle single declarations only");
assert(Synthetic != Source && "Don't include original DeclStmts in map");
assert(!SyntheticDeclStmts.count(Synthetic) && "Already in map");
SyntheticDeclStmts[Synthetic] = Source;
}
typedef llvm::DenseMap<const DeclStmt *, const DeclStmt *>::const_iterator
synthetic_stmt_iterator;
/// Iterates over synthetic DeclStmts in the CFG.
///
/// Each element is a (synthetic statement, source statement) pair.
///
/// \sa addSyntheticDeclStmt
synthetic_stmt_iterator synthetic_stmt_begin() const {
return SyntheticDeclStmts.begin();
}
/// \sa synthetic_stmt_begin
synthetic_stmt_iterator synthetic_stmt_end() const {
return SyntheticDeclStmts.end();
}
//===--------------------------------------------------------------------===//
// Member templates useful for various batch operations over CFGs.
//===--------------------------------------------------------------------===//
template <typename CALLBACK>
void VisitBlockStmts(CALLBACK& O) const {
for (const_iterator I=begin(), E=end(); I != E; ++I)
for (CFGBlock::const_iterator BI=(*I)->begin(), BE=(*I)->end();
BI != BE; ++BI) {
if (Optional<CFGStmt> stmt = BI->getAs<CFGStmt>())
O(const_cast<Stmt*>(stmt->getStmt()));
}
}
//===--------------------------------------------------------------------===//
// CFG Introspection.
//===--------------------------------------------------------------------===//
/// getNumBlockIDs - Returns the total number of BlockIDs allocated (which
/// start at 0).
unsigned getNumBlockIDs() const { return NumBlockIDs; }
/// size - Return the total number of CFGBlocks within the CFG
/// This is simply a renaming of the getNumBlockIDs(). This is necessary
/// because the dominator implementation needs such an interface.
unsigned size() const { return NumBlockIDs; }
//===--------------------------------------------------------------------===//
// CFG Debugging: Pretty-Printing and Visualization.
//===--------------------------------------------------------------------===//
void viewCFG(const LangOptions &LO) const;
void print(raw_ostream &OS, const LangOptions &LO, bool ShowColors) const;
void dump(const LangOptions &LO, bool ShowColors) const;
//===--------------------------------------------------------------------===//
// Internal: constructors and data.
//===--------------------------------------------------------------------===//
CFG() : Entry(NULL), Exit(NULL), IndirectGotoBlock(NULL), NumBlockIDs(0),
Blocks(BlkBVC, 10) {}
llvm::BumpPtrAllocator& getAllocator() {
return BlkBVC.getAllocator();
}
BumpVectorContext &getBumpVectorContext() {
return BlkBVC;
}
private:
CFGBlock *Entry;
CFGBlock *Exit;
CFGBlock* IndirectGotoBlock; // Special block to contain collective dispatch
// for indirect gotos
unsigned NumBlockIDs;
BumpVectorContext BlkBVC;
CFGBlockListTy Blocks;
/// C++ 'try' statements are modeled with an indirect dispatch block.
/// This is the collection of such blocks present in the CFG.
std::vector<const CFGBlock *> TryDispatchBlocks;
/// Collects DeclStmts synthesized for this CFG and maps each one back to its
/// source DeclStmt.
llvm::DenseMap<const DeclStmt *, const DeclStmt *> SyntheticDeclStmts;
};
} // end namespace clang
//===----------------------------------------------------------------------===//
// GraphTraits specializations for CFG basic block graphs (source-level CFGs)
//===----------------------------------------------------------------------===//
namespace llvm {
/// Implement simplify_type for CFGTerminator, so that we can dyn_cast from
/// CFGTerminator to a specific Stmt class.
template <> struct simplify_type< ::clang::CFGTerminator> {
typedef ::clang::Stmt *SimpleType;
static SimpleType getSimplifiedValue(::clang::CFGTerminator Val) {
return Val.getStmt();
}
};
// Traits for: CFGBlock
template <> struct GraphTraits< ::clang::CFGBlock *> {
typedef ::clang::CFGBlock NodeType;
typedef ::clang::CFGBlock::succ_iterator ChildIteratorType;
static NodeType* getEntryNode(::clang::CFGBlock *BB)
{ return BB; }
static inline ChildIteratorType child_begin(NodeType* N)
{ return N->succ_begin(); }
static inline ChildIteratorType child_end(NodeType* N)
{ return N->succ_end(); }
};
template <> struct GraphTraits< const ::clang::CFGBlock *> {
typedef const ::clang::CFGBlock NodeType;
typedef ::clang::CFGBlock::const_succ_iterator ChildIteratorType;
static NodeType* getEntryNode(const clang::CFGBlock *BB)
{ return BB; }
static inline ChildIteratorType child_begin(NodeType* N)
{ return N->succ_begin(); }
static inline ChildIteratorType child_end(NodeType* N)
{ return N->succ_end(); }
};
template <> struct GraphTraits<Inverse< ::clang::CFGBlock*> > {
typedef ::clang::CFGBlock NodeType;
typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType;
static NodeType *getEntryNode(Inverse< ::clang::CFGBlock*> G)
{ return G.Graph; }
static inline ChildIteratorType child_begin(NodeType* N)
{ return N->pred_begin(); }
static inline ChildIteratorType child_end(NodeType* N)
{ return N->pred_end(); }
};
template <> struct GraphTraits<Inverse<const ::clang::CFGBlock*> > {
typedef const ::clang::CFGBlock NodeType;
typedef ::clang::CFGBlock::const_pred_iterator ChildIteratorType;
static NodeType *getEntryNode(Inverse<const ::clang::CFGBlock*> G)
{ return G.Graph; }
static inline ChildIteratorType child_begin(NodeType* N)
{ return N->pred_begin(); }
static inline ChildIteratorType child_end(NodeType* N)
{ return N->pred_end(); }
};
// Traits for: CFG
template <> struct GraphTraits< ::clang::CFG* >
: public GraphTraits< ::clang::CFGBlock *> {
typedef ::clang::CFG::graph_iterator nodes_iterator;
static NodeType *getEntryNode(::clang::CFG* F) { return &F->getEntry(); }
static nodes_iterator nodes_begin(::clang::CFG* F) { return F->nodes_begin();}
static nodes_iterator nodes_end(::clang::CFG* F) { return F->nodes_end(); }
static unsigned size(::clang::CFG* F) { return F->size(); }
};
template <> struct GraphTraits<const ::clang::CFG* >
: public GraphTraits<const ::clang::CFGBlock *> {
typedef ::clang::CFG::const_graph_iterator nodes_iterator;
static NodeType *getEntryNode( const ::clang::CFG* F) {
return &F->getEntry();
}
static nodes_iterator nodes_begin( const ::clang::CFG* F) {
return F->nodes_begin();
}
static nodes_iterator nodes_end( const ::clang::CFG* F) {
return F->nodes_end();
}
static unsigned size(const ::clang::CFG* F) {
return F->size();
}
};
template <> struct GraphTraits<Inverse< ::clang::CFG*> >
: public GraphTraits<Inverse< ::clang::CFGBlock*> > {
typedef ::clang::CFG::graph_iterator nodes_iterator;
static NodeType *getEntryNode( ::clang::CFG* F) { return &F->getExit(); }
static nodes_iterator nodes_begin( ::clang::CFG* F) {return F->nodes_begin();}
static nodes_iterator nodes_end( ::clang::CFG* F) { return F->nodes_end(); }
};
template <> struct GraphTraits<Inverse<const ::clang::CFG*> >
: public GraphTraits<Inverse<const ::clang::CFGBlock*> > {
typedef ::clang::CFG::const_graph_iterator nodes_iterator;
static NodeType *getEntryNode(const ::clang::CFG* F) { return &F->getExit(); }
static nodes_iterator nodes_begin(const ::clang::CFG* F) {
return F->nodes_begin();
}
static nodes_iterator nodes_end(const ::clang::CFG* F) {
return F->nodes_end();
}
};
} // end llvm namespace
#endif