From f27e5a09a0d815b8a4814152954ff87dadfdefc0 Mon Sep 17 00:00:00 2001 From: ed Date: Tue, 2 Jun 2009 17:58:47 +0000 Subject: Import Clang, at r72732. --- include/clang/AST/CFG.h | 405 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 405 insertions(+) create mode 100644 include/clang/AST/CFG.h (limited to 'include/clang/AST/CFG.h') diff --git a/include/clang/AST/CFG.h b/include/clang/AST/CFG.h new file mode 100644 index 0000000..7a9ee01 --- /dev/null +++ b/include/clang/AST/CFG.h @@ -0,0 +1,405 @@ +//===--- 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 "llvm/ADT/GraphTraits.h" +#include "llvm/Support/Allocator.h" +#include "llvm/Support/raw_ostream.h" +#include +#include +#include + +namespace clang { + class Stmt; + class Expr; + class CFG; + class PrinterHelper; + class BlockEdge; + +/// 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 +/// +class CFGBlock { + typedef std::vector StatementListTy; + /// Stmts - The set of statements in the basic block. + StatementListTy Stmts; + + /// 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 or SwitchCase. + Stmt *Label; + + /// Terminator - The terminator for a basic block that + /// indicates the type of control-flow that occurs between a block + /// and its successors. + Stmt *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; + + /// Predecessors/Successors - Keep track of the predecessor / successor + /// CFG blocks. + typedef std::vector AdjacentBlocks; + AdjacentBlocks Preds; + AdjacentBlocks Succs; + +public: + explicit CFGBlock(unsigned blockid) : Label(NULL), Terminator(NULL), + LoopTarget(NULL), BlockID(blockid) {} + ~CFGBlock() {}; + + // Statement iterators + typedef StatementListTy::iterator iterator; + typedef StatementListTy::const_iterator const_iterator; + typedef std::reverse_iterator const_reverse_iterator; + typedef std::reverse_iterator reverse_iterator; + + Stmt* front() const { return Stmts.front(); } + Stmt* back() const { return Stmts.back(); } + + iterator begin() { return Stmts.begin(); } + iterator end() { return Stmts.end(); } + const_iterator begin() const { return Stmts.begin(); } + const_iterator end() const { return Stmts.end(); } + + reverse_iterator rbegin() { return Stmts.rbegin(); } + reverse_iterator rend() { return Stmts.rend(); } + const_reverse_iterator rbegin() const { return Stmts.rbegin(); } + const_reverse_iterator rend() const { return Stmts.rend(); } + + unsigned size() const { return Stmts.size(); } + bool empty() const { return Stmts.empty(); } + + Stmt* operator[](size_t i) const { assert (i < size()); return Stmts[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(); } + + // Manipulation of block contents + + void appendStmt(Stmt* Statement) { Stmts.push_back(Statement); } + void setTerminator(Stmt* Statement) { Terminator = Statement; } + void setLabel(Stmt* Statement) { Label = Statement; } + void setLoopTarget(const Stmt *loopTarget) { LoopTarget = loopTarget; } + + Stmt* getTerminator() { return Terminator; } + const Stmt* getTerminator() const { return Terminator; } + + Stmt* getTerminatorCondition(); + + const Stmt* getTerminatorCondition() const { + return const_cast(this)->getTerminatorCondition(); + } + + const Stmt *getLoopTarget() const { return LoopTarget; } + + bool hasBinaryBranchTerminator() const; + + Stmt* getLabel() { return Label; } + const Stmt* getLabel() const { return Label; } + + void reverseStmts(); + + void addSuccessor(CFGBlock* Block) { + Block->Preds.push_back(this); + Succs.push_back(Block); + } + + unsigned getBlockID() const { return BlockID; } + + void dump(const CFG* cfg) const; + void print(llvm::raw_ostream& OS, const CFG* cfg) const; + void printTerminator(llvm::raw_ostream& OS) const; +}; + + +/// 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. + //===--------------------------------------------------------------------===// + + /// buildCFG - Builds a CFG from an AST. The responsibility to free the + /// constructed CFG belongs to the caller. + static CFG* buildCFG(Stmt* AST); + + /// 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; } + + /// setExit - Set the exit block of the CFG. This is typically used + /// only during CFG construction. Most CFG clients expect that the + /// exit block has no successors and contains no statements. + void setIndirectGotoBlock(CFGBlock* B) { IndirectGotoBlock = B; } + + //===--------------------------------------------------------------------===// + // Block Iterators + //===--------------------------------------------------------------------===// + + typedef std::list CFGBlockListTy; + + typedef CFGBlockListTy::iterator iterator; + typedef CFGBlockListTy::const_iterator const_iterator; + typedef std::reverse_iterator reverse_iterator; + typedef std::reverse_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(); } + + 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; } + + //===--------------------------------------------------------------------===// + // Member templates useful for various batch operations over CFGs. + //===--------------------------------------------------------------------===// + + template + 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) + O(*BI); + } + + //===--------------------------------------------------------------------===// + // CFG Introspection. + //===--------------------------------------------------------------------===// + + struct BlkExprNumTy { + const signed Idx; + explicit BlkExprNumTy(signed idx) : Idx(idx) {} + explicit BlkExprNumTy() : Idx(-1) {} + operator bool() const { return Idx >= 0; } + operator unsigned() const { assert(Idx >=0); return (unsigned) Idx; } + }; + + bool isBlkExpr(const Stmt* S) { return getBlkExprNum(S); } + BlkExprNumTy getBlkExprNum(const Stmt* S); + unsigned getNumBlkExprs(); + + unsigned getNumBlockIDs() const { return NumBlockIDs; } + + //===--------------------------------------------------------------------===// + // CFG Debugging: Pretty-Printing and Visualization. + //===--------------------------------------------------------------------===// + + void viewCFG() const; + void print(llvm::raw_ostream& OS) const; + void dump() const; + + //===--------------------------------------------------------------------===// + // Internal: constructors and data. + //===--------------------------------------------------------------------===// + + CFG() : Entry(NULL), Exit(NULL), IndirectGotoBlock(NULL), NumBlockIDs(0), + BlkExprMap(NULL) {}; + + ~CFG(); + + llvm::BumpPtrAllocator& getAllocator() { + return Alloc; + } + +private: + CFGBlock* Entry; + CFGBlock* Exit; + CFGBlock* IndirectGotoBlock; // Special block to contain collective dispatch + // for indirect gotos + CFGBlockListTy Blocks; + unsigned NumBlockIDs; + + // BlkExprMap - An opaque pointer to prevent inclusion of DenseMap.h. + // It represents a map from Expr* to integers to record the set of + // block-level expressions and their "statement number" in the CFG. + void* BlkExprMap; + + /// Alloc - An internal allocator. + llvm::BumpPtrAllocator Alloc; +}; +} // end namespace clang + +//===----------------------------------------------------------------------===// +// GraphTraits specializations for CFG basic block graphs (source-level CFGs) +//===----------------------------------------------------------------------===// + +namespace llvm { + +// Traits for: CFGBlock + +template <> struct GraphTraits { + 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 { + 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 > { + typedef const clang::CFGBlock NodeType; + typedef clang::CFGBlock::const_pred_iterator ChildIteratorType; + + static NodeType *getEntryNode(Inverse 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 + : public GraphTraits { + + typedef clang::CFG::iterator nodes_iterator; + + static NodeType *getEntryNode(clang::CFG* F) { return &F->getEntry(); } + static nodes_iterator nodes_begin(clang::CFG* F) { return F->begin(); } + static nodes_iterator nodes_end(clang::CFG* F) { return F->end(); } +}; + +template <> struct GraphTraits< const clang::CFG* > + : public GraphTraits< const clang::CFGBlock* > { + + typedef clang::CFG::const_iterator nodes_iterator; + + static NodeType *getEntryNode( const clang::CFG* F) { return &F->getEntry(); } + static nodes_iterator nodes_begin( const clang::CFG* F) { return F->begin(); } + static nodes_iterator nodes_end( const clang::CFG* F) { return F->end(); } +}; + +template <> struct GraphTraits > + : public GraphTraits > { + + typedef clang::CFG::const_iterator nodes_iterator; + + static NodeType *getEntryNode(const clang::CFG* F) { return &F->getExit(); } + static nodes_iterator nodes_begin(const clang::CFG* F) { return F->begin();} + static nodes_iterator nodes_end(const clang::CFG* F) { return F->end(); } +}; + +} // end llvm namespace + +#endif -- cgit v1.1