Check in LLVM r95781.
diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
new file mode 100644
index 0000000..5b8aeae
--- /dev/null
+++ b/lib/Analysis/CFG.cpp
@@ -0,0 +1,2339 @@
+//===--- CFG.cpp - 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.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/Support/SaveAndRestore.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/AST/PrettyPrinter.h"
+#include "llvm/Support/GraphWriter.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Format.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/OwningPtr.h"
+
+using namespace clang;
+
+namespace {
+
+static SourceLocation GetEndLoc(Decl* D) {
+ if (VarDecl* VD = dyn_cast<VarDecl>(D))
+ if (Expr* Ex = VD->getInit())
+ return Ex->getSourceRange().getEnd();
+
+ return D->getLocation();
+}
+
+class AddStmtChoice {
+public:
+ enum Kind { NotAlwaysAdd = 0, AlwaysAdd, AlwaysAddAsLValue };
+public:
+ AddStmtChoice(Kind kind) : k(kind) {}
+ bool alwaysAdd() const { return k != NotAlwaysAdd; }
+ bool asLValue() const { return k == AlwaysAddAsLValue; }
+private:
+ Kind k;
+};
+
+/// CFGBuilder - This class implements CFG construction from an AST.
+/// The builder is stateful: an instance of the builder should be used to only
+/// construct a single CFG.
+///
+/// Example usage:
+///
+/// CFGBuilder builder;
+/// CFG* cfg = builder.BuildAST(stmt1);
+///
+/// CFG construction is done via a recursive walk of an AST. We actually parse
+/// the AST in reverse order so that the successor of a basic block is
+/// constructed prior to its predecessor. This allows us to nicely capture
+/// implicit fall-throughs without extra basic blocks.
+///
+class CFGBuilder {
+ ASTContext *Context;
+ llvm::OwningPtr<CFG> cfg;
+
+ CFGBlock* Block;
+ CFGBlock* Succ;
+ CFGBlock* ContinueTargetBlock;
+ CFGBlock* BreakTargetBlock;
+ CFGBlock* SwitchTerminatedBlock;
+ CFGBlock* DefaultCaseBlock;
+ CFGBlock* TryTerminatedBlock;
+
+ // LabelMap records the mapping from Label expressions to their blocks.
+ typedef llvm::DenseMap<LabelStmt*,CFGBlock*> LabelMapTy;
+ LabelMapTy LabelMap;
+
+ // A list of blocks that end with a "goto" that must be backpatched to their
+ // resolved targets upon completion of CFG construction.
+ typedef std::vector<CFGBlock*> BackpatchBlocksTy;
+ BackpatchBlocksTy BackpatchBlocks;
+
+ // A list of labels whose address has been taken (for indirect gotos).
+ typedef llvm::SmallPtrSet<LabelStmt*,5> LabelSetTy;
+ LabelSetTy AddressTakenLabels;
+
+public:
+ explicit CFGBuilder() : cfg(new CFG()), // crew a new CFG
+ Block(NULL), Succ(NULL),
+ ContinueTargetBlock(NULL), BreakTargetBlock(NULL),
+ SwitchTerminatedBlock(NULL), DefaultCaseBlock(NULL),
+ TryTerminatedBlock(NULL) {}
+
+ // buildCFG - Used by external clients to construct the CFG.
+ CFG* buildCFG(const Decl *D, Stmt *Statement, ASTContext *C, bool AddEHEdges,
+ bool AddScopes);
+
+private:
+ // Visitors to walk an AST and construct the CFG.
+ CFGBlock *VisitAddrLabelExpr(AddrLabelExpr *A, AddStmtChoice asc);
+ CFGBlock *VisitBinaryOperator(BinaryOperator *B, AddStmtChoice asc);
+ CFGBlock *VisitBlockExpr(BlockExpr* E, AddStmtChoice asc);
+ CFGBlock *VisitBreakStmt(BreakStmt *B);
+ CFGBlock *VisitCallExpr(CallExpr *C, AddStmtChoice asc);
+ CFGBlock *VisitCaseStmt(CaseStmt *C);
+ CFGBlock *VisitChooseExpr(ChooseExpr *C, AddStmtChoice asc);
+ CFGBlock *VisitCompoundStmt(CompoundStmt *C);
+ CFGBlock *VisitConditionalOperator(ConditionalOperator *C,
+ AddStmtChoice asc);
+ CFGBlock *VisitContinueStmt(ContinueStmt *C);
+ CFGBlock *VisitCXXCatchStmt(CXXCatchStmt *S);
+ CFGBlock *VisitCXXThrowExpr(CXXThrowExpr *T);
+ CFGBlock *VisitCXXTryStmt(CXXTryStmt *S);
+ CFGBlock *VisitDeclStmt(DeclStmt *DS);
+ CFGBlock *VisitDeclSubExpr(Decl* D);
+ CFGBlock *VisitDefaultStmt(DefaultStmt *D);
+ CFGBlock *VisitDoStmt(DoStmt *D);
+ CFGBlock *VisitForStmt(ForStmt *F);
+ CFGBlock *VisitGotoStmt(GotoStmt* G);
+ CFGBlock *VisitIfStmt(IfStmt *I);
+ CFGBlock *VisitIndirectGotoStmt(IndirectGotoStmt *I);
+ CFGBlock *VisitLabelStmt(LabelStmt *L);
+ CFGBlock *VisitObjCAtCatchStmt(ObjCAtCatchStmt *S);
+ CFGBlock *VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S);
+ CFGBlock *VisitObjCAtThrowStmt(ObjCAtThrowStmt *S);
+ CFGBlock *VisitObjCAtTryStmt(ObjCAtTryStmt *S);
+ CFGBlock *VisitObjCForCollectionStmt(ObjCForCollectionStmt *S);
+ CFGBlock *VisitReturnStmt(ReturnStmt* R);
+ CFGBlock *VisitSizeOfAlignOfExpr(SizeOfAlignOfExpr *E, AddStmtChoice asc);
+ CFGBlock *VisitStmtExpr(StmtExpr *S, AddStmtChoice asc);
+ CFGBlock *VisitSwitchStmt(SwitchStmt *S);
+ CFGBlock *VisitWhileStmt(WhileStmt *W);
+
+ CFGBlock *Visit(Stmt *S, AddStmtChoice asc = AddStmtChoice::NotAlwaysAdd);
+ CFGBlock *VisitStmt(Stmt *S, AddStmtChoice asc);
+ CFGBlock *VisitChildren(Stmt* S);
+
+ // NYS == Not Yet Supported
+ CFGBlock* NYS() {
+ badCFG = true;
+ return Block;
+ }
+
+ CFGBlock *StartScope(Stmt *S, CFGBlock *B) {
+ if (!AddScopes)
+ return B;
+
+ if (B == 0)
+ B = createBlock();
+ B->StartScope(S, cfg->getBumpVectorContext());
+ return B;
+ }
+
+ void EndScope(Stmt *S) {
+ if (!AddScopes)
+ return;
+
+ if (Block == 0)
+ Block = createBlock();
+ Block->EndScope(S, cfg->getBumpVectorContext());
+ }
+
+ void autoCreateBlock() { if (!Block) Block = createBlock(); }
+ CFGBlock *createBlock(bool add_successor = true);
+ bool FinishBlock(CFGBlock* B);
+ CFGBlock *addStmt(Stmt *S, AddStmtChoice asc = AddStmtChoice::AlwaysAdd) {
+ return Visit(S, asc);
+ }
+
+ void AppendStmt(CFGBlock *B, Stmt *S,
+ AddStmtChoice asc = AddStmtChoice::AlwaysAdd) {
+ B->appendStmt(S, cfg->getBumpVectorContext(), asc.asLValue());
+ }
+
+ void AddSuccessor(CFGBlock *B, CFGBlock *S) {
+ B->addSuccessor(S, cfg->getBumpVectorContext());
+ }
+
+ /// TryResult - a class representing a variant over the values
+ /// 'true', 'false', or 'unknown'. This is returned by TryEvaluateBool,
+ /// and is used by the CFGBuilder to decide if a branch condition
+ /// can be decided up front during CFG construction.
+ class TryResult {
+ int X;
+ public:
+ TryResult(bool b) : X(b ? 1 : 0) {}
+ TryResult() : X(-1) {}
+
+ bool isTrue() const { return X == 1; }
+ bool isFalse() const { return X == 0; }
+ bool isKnown() const { return X >= 0; }
+ void negate() {
+ assert(isKnown());
+ X ^= 0x1;
+ }
+ };
+
+ /// TryEvaluateBool - Try and evaluate the Stmt and return 0 or 1
+ /// if we can evaluate to a known value, otherwise return -1.
+ TryResult TryEvaluateBool(Expr *S) {
+ Expr::EvalResult Result;
+ if (!S->isTypeDependent() && !S->isValueDependent() &&
+ S->Evaluate(Result, *Context) && Result.Val.isInt())
+ return Result.Val.getInt().getBoolValue();
+
+ return TryResult();
+ }
+
+ bool badCFG;
+
+ // True iff EH edges on CallExprs should be added to the CFG.
+ bool AddEHEdges;
+
+ // True iff scope start and scope end notes should be added to the CFG.
+ bool AddScopes;
+};
+
+// FIXME: Add support for dependent-sized array types in C++?
+// Does it even make sense to build a CFG for an uninstantiated template?
+static VariableArrayType* FindVA(Type* t) {
+ while (ArrayType* vt = dyn_cast<ArrayType>(t)) {
+ if (VariableArrayType* vat = dyn_cast<VariableArrayType>(vt))
+ if (vat->getSizeExpr())
+ return vat;
+
+ t = vt->getElementType().getTypePtr();
+ }
+
+ return 0;
+}
+
+/// BuildCFG - Constructs a CFG from an AST (a Stmt*). The AST can represent an
+/// arbitrary statement. Examples include a single expression or a function
+/// body (compound statement). The ownership of the returned CFG is
+/// transferred to the caller. If CFG construction fails, this method returns
+/// NULL.
+CFG* CFGBuilder::buildCFG(const Decl *D, Stmt* Statement, ASTContext* C,
+ bool addehedges, bool AddScopes) {
+ AddEHEdges = addehedges;
+ Context = C;
+ assert(cfg.get());
+ if (!Statement)
+ return NULL;
+
+ this->AddScopes = AddScopes;
+ badCFG = false;
+
+ // Create an empty block that will serve as the exit block for the CFG. Since
+ // this is the first block added to the CFG, it will be implicitly registered
+ // as the exit block.
+ Succ = createBlock();
+ assert(Succ == &cfg->getExit());
+ Block = NULL; // the EXIT block is empty. Create all other blocks lazily.
+
+ // Visit the statements and create the CFG.
+ CFGBlock* B = addStmt(Statement);
+
+ if (const CXXConstructorDecl *CD = dyn_cast_or_null<CXXConstructorDecl>(D)) {
+ // FIXME: Add code for base initializers and member initializers.
+ (void)CD;
+ }
+ if (!B)
+ B = Succ;
+
+ if (B) {
+ // Finalize the last constructed block. This usually involves reversing the
+ // order of the statements in the block.
+ if (Block) FinishBlock(B);
+
+ // Backpatch the gotos whose label -> block mappings we didn't know when we
+ // encountered them.
+ for (BackpatchBlocksTy::iterator I = BackpatchBlocks.begin(),
+ E = BackpatchBlocks.end(); I != E; ++I ) {
+
+ CFGBlock* B = *I;
+ GotoStmt* G = cast<GotoStmt>(B->getTerminator());
+ LabelMapTy::iterator LI = LabelMap.find(G->getLabel());
+
+ // If there is no target for the goto, then we are looking at an
+ // incomplete AST. Handle this by not registering a successor.
+ if (LI == LabelMap.end()) continue;
+
+ AddSuccessor(B, LI->second);
+ }
+
+ // Add successors to the Indirect Goto Dispatch block (if we have one).
+ if (CFGBlock* B = cfg->getIndirectGotoBlock())
+ for (LabelSetTy::iterator I = AddressTakenLabels.begin(),
+ E = AddressTakenLabels.end(); I != E; ++I ) {
+
+ // Lookup the target block.
+ LabelMapTy::iterator LI = LabelMap.find(*I);
+
+ // If there is no target block that contains label, then we are looking
+ // at an incomplete AST. Handle this by not registering a successor.
+ if (LI == LabelMap.end()) continue;
+
+ AddSuccessor(B, LI->second);
+ }
+
+ Succ = B;
+ }
+
+ // Create an empty entry block that has no predecessors.
+ cfg->setEntry(createBlock());
+
+ return badCFG ? NULL : cfg.take();
+}
+
+/// createBlock - Used to lazily create blocks that are connected
+/// to the current (global) succcessor.
+CFGBlock* CFGBuilder::createBlock(bool add_successor) {
+ CFGBlock* B = cfg->createBlock();
+ if (add_successor && Succ)
+ AddSuccessor(B, Succ);
+ return B;
+}
+
+/// FinishBlock - "Finalize" the block by checking if we have a bad CFG.
+bool CFGBuilder::FinishBlock(CFGBlock* B) {
+ if (badCFG)
+ return false;
+
+ assert(B);
+ return true;
+}
+
+/// Visit - Walk the subtree of a statement and add extra
+/// blocks for ternary operators, &&, and ||. We also process "," and
+/// DeclStmts (which may contain nested control-flow).
+CFGBlock* CFGBuilder::Visit(Stmt * S, AddStmtChoice asc) {
+tryAgain:
+ switch (S->getStmtClass()) {
+ default:
+ return VisitStmt(S, asc);
+
+ case Stmt::AddrLabelExprClass:
+ return VisitAddrLabelExpr(cast<AddrLabelExpr>(S), asc);
+
+ case Stmt::BinaryOperatorClass:
+ return VisitBinaryOperator(cast<BinaryOperator>(S), asc);
+
+ case Stmt::BlockExprClass:
+ return VisitBlockExpr(cast<BlockExpr>(S), asc);
+
+ case Stmt::BreakStmtClass:
+ return VisitBreakStmt(cast<BreakStmt>(S));
+
+ case Stmt::CallExprClass:
+ return VisitCallExpr(cast<CallExpr>(S), asc);
+
+ case Stmt::CaseStmtClass:
+ return VisitCaseStmt(cast<CaseStmt>(S));
+
+ case Stmt::ChooseExprClass:
+ return VisitChooseExpr(cast<ChooseExpr>(S), asc);
+
+ case Stmt::CompoundStmtClass:
+ return VisitCompoundStmt(cast<CompoundStmt>(S));
+
+ case Stmt::ConditionalOperatorClass:
+ return VisitConditionalOperator(cast<ConditionalOperator>(S), asc);
+
+ case Stmt::ContinueStmtClass:
+ return VisitContinueStmt(cast<ContinueStmt>(S));
+
+ case Stmt::CXXCatchStmtClass:
+ return VisitCXXCatchStmt(cast<CXXCatchStmt>(S));
+
+ case Stmt::CXXThrowExprClass:
+ return VisitCXXThrowExpr(cast<CXXThrowExpr>(S));
+
+ case Stmt::CXXTryStmtClass:
+ return VisitCXXTryStmt(cast<CXXTryStmt>(S));
+
+ case Stmt::DeclStmtClass:
+ return VisitDeclStmt(cast<DeclStmt>(S));
+
+ case Stmt::DefaultStmtClass:
+ return VisitDefaultStmt(cast<DefaultStmt>(S));
+
+ case Stmt::DoStmtClass:
+ return VisitDoStmt(cast<DoStmt>(S));
+
+ case Stmt::ForStmtClass:
+ return VisitForStmt(cast<ForStmt>(S));
+
+ case Stmt::GotoStmtClass:
+ return VisitGotoStmt(cast<GotoStmt>(S));
+
+ case Stmt::IfStmtClass:
+ return VisitIfStmt(cast<IfStmt>(S));
+
+ case Stmt::IndirectGotoStmtClass:
+ return VisitIndirectGotoStmt(cast<IndirectGotoStmt>(S));
+
+ case Stmt::LabelStmtClass:
+ return VisitLabelStmt(cast<LabelStmt>(S));
+
+ case Stmt::ObjCAtCatchStmtClass:
+ return VisitObjCAtCatchStmt(cast<ObjCAtCatchStmt>(S));
+
+ case Stmt::ObjCAtSynchronizedStmtClass:
+ return VisitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(S));
+
+ case Stmt::ObjCAtThrowStmtClass:
+ return VisitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(S));
+
+ case Stmt::ObjCAtTryStmtClass:
+ return VisitObjCAtTryStmt(cast<ObjCAtTryStmt>(S));
+
+ case Stmt::ObjCForCollectionStmtClass:
+ return VisitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(S));
+
+ case Stmt::ParenExprClass:
+ S = cast<ParenExpr>(S)->getSubExpr();
+ goto tryAgain;
+
+ case Stmt::NullStmtClass:
+ return Block;
+
+ case Stmt::ReturnStmtClass:
+ return VisitReturnStmt(cast<ReturnStmt>(S));
+
+ case Stmt::SizeOfAlignOfExprClass:
+ return VisitSizeOfAlignOfExpr(cast<SizeOfAlignOfExpr>(S), asc);
+
+ case Stmt::StmtExprClass:
+ return VisitStmtExpr(cast<StmtExpr>(S), asc);
+
+ case Stmt::SwitchStmtClass:
+ return VisitSwitchStmt(cast<SwitchStmt>(S));
+
+ case Stmt::WhileStmtClass:
+ return VisitWhileStmt(cast<WhileStmt>(S));
+ }
+}
+
+CFGBlock *CFGBuilder::VisitStmt(Stmt *S, AddStmtChoice asc) {
+ if (asc.alwaysAdd()) {
+ autoCreateBlock();
+ AppendStmt(Block, S, asc);
+ }
+
+ return VisitChildren(S);
+}
+
+/// VisitChildren - Visit the children of a Stmt.
+CFGBlock *CFGBuilder::VisitChildren(Stmt* Terminator) {
+ CFGBlock *B = Block;
+ for (Stmt::child_iterator I = Terminator->child_begin(),
+ E = Terminator->child_end(); I != E; ++I) {
+ if (*I) B = Visit(*I);
+ }
+ return B;
+}
+
+CFGBlock *CFGBuilder::VisitAddrLabelExpr(AddrLabelExpr *A,
+ AddStmtChoice asc) {
+ AddressTakenLabels.insert(A->getLabel());
+
+ if (asc.alwaysAdd()) {
+ autoCreateBlock();
+ AppendStmt(Block, A, asc);
+ }
+
+ return Block;
+}
+
+CFGBlock *CFGBuilder::VisitBinaryOperator(BinaryOperator *B,
+ AddStmtChoice asc) {
+ if (B->isLogicalOp()) { // && or ||
+ CFGBlock* ConfluenceBlock = Block ? Block : createBlock();
+ AppendStmt(ConfluenceBlock, B, asc);
+
+ if (!FinishBlock(ConfluenceBlock))
+ return 0;
+
+ // create the block evaluating the LHS
+ CFGBlock* LHSBlock = createBlock(false);
+ LHSBlock->setTerminator(B);
+
+ // create the block evaluating the RHS
+ Succ = ConfluenceBlock;
+ Block = NULL;
+ CFGBlock* RHSBlock = addStmt(B->getRHS());
+ if (!FinishBlock(RHSBlock))
+ return 0;
+
+ // See if this is a known constant.
+ TryResult KnownVal = TryEvaluateBool(B->getLHS());
+ if (KnownVal.isKnown() && (B->getOpcode() == BinaryOperator::LOr))
+ KnownVal.negate();
+
+ // Now link the LHSBlock with RHSBlock.
+ if (B->getOpcode() == BinaryOperator::LOr) {
+ AddSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock);
+ AddSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
+ } else {
+ assert(B->getOpcode() == BinaryOperator::LAnd);
+ AddSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
+ AddSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock);
+ }
+
+ // Generate the blocks for evaluating the LHS.
+ Block = LHSBlock;
+ return addStmt(B->getLHS());
+ }
+ else if (B->getOpcode() == BinaryOperator::Comma) { // ,
+ autoCreateBlock();
+ AppendStmt(Block, B, asc);
+ addStmt(B->getRHS());
+ return addStmt(B->getLHS());
+ }
+
+ return VisitStmt(B, asc);
+}
+
+CFGBlock *CFGBuilder::VisitBlockExpr(BlockExpr *E, AddStmtChoice asc) {
+ if (asc.alwaysAdd()) {
+ autoCreateBlock();
+ AppendStmt(Block, E, asc);
+ }
+ return Block;
+}
+
+CFGBlock *CFGBuilder::VisitBreakStmt(BreakStmt *B) {
+ // "break" is a control-flow statement. Thus we stop processing the current
+ // block.
+ if (Block && !FinishBlock(Block))
+ return 0;
+
+ // Now create a new block that ends with the break statement.
+ Block = createBlock(false);
+ Block->setTerminator(B);
+
+ // If there is no target for the break, then we are looking at an incomplete
+ // AST. This means that the CFG cannot be constructed.
+ if (BreakTargetBlock)
+ AddSuccessor(Block, BreakTargetBlock);
+ else
+ badCFG = true;
+
+
+ return Block;
+}
+
+static bool CanThrow(Expr *E) {
+ QualType Ty = E->getType();
+ if (Ty->isFunctionPointerType())
+ Ty = Ty->getAs<PointerType>()->getPointeeType();
+ else if (Ty->isBlockPointerType())
+ Ty = Ty->getAs<BlockPointerType>()->getPointeeType();
+
+ const FunctionType *FT = Ty->getAs<FunctionType>();
+ if (FT) {
+ if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT))
+ if (Proto->hasEmptyExceptionSpec())
+ return false;
+ }
+ return true;
+}
+
+CFGBlock *CFGBuilder::VisitCallExpr(CallExpr *C, AddStmtChoice asc) {
+ // If this is a call to a no-return function, this stops the block here.
+ bool NoReturn = false;
+ if (C->getCallee()->getType().getNoReturnAttr()) {
+ NoReturn = true;
+ }
+
+ bool AddEHEdge = false;
+
+ // Languages without exceptions are assumed to not throw.
+ if (Context->getLangOptions().Exceptions) {
+ if (AddEHEdges)
+ AddEHEdge = true;
+ }
+
+ if (FunctionDecl *FD = C->getDirectCallee()) {
+ if (FD->hasAttr<NoReturnAttr>())
+ NoReturn = true;
+ if (FD->hasAttr<NoThrowAttr>())
+ AddEHEdge = false;
+ }
+
+ if (!CanThrow(C->getCallee()))
+ AddEHEdge = false;
+
+ if (!NoReturn && !AddEHEdge)
+ return VisitStmt(C, asc);
+
+ if (Block) {
+ Succ = Block;
+ if (!FinishBlock(Block))
+ return 0;
+ }
+
+ Block = createBlock(!NoReturn);
+ AppendStmt(Block, C, asc);
+
+ if (NoReturn) {
+ // Wire this to the exit block directly.
+ AddSuccessor(Block, &cfg->getExit());
+ }
+ if (AddEHEdge) {
+ // Add exceptional edges.
+ if (TryTerminatedBlock)
+ AddSuccessor(Block, TryTerminatedBlock);
+ else
+ AddSuccessor(Block, &cfg->getExit());
+ }
+
+ return VisitChildren(C);
+}
+
+CFGBlock *CFGBuilder::VisitChooseExpr(ChooseExpr *C,
+ AddStmtChoice asc) {
+ CFGBlock* ConfluenceBlock = Block ? Block : createBlock();
+ AppendStmt(ConfluenceBlock, C, asc);
+ if (!FinishBlock(ConfluenceBlock))
+ return 0;
+
+ Succ = ConfluenceBlock;
+ Block = NULL;
+ CFGBlock* LHSBlock = addStmt(C->getLHS());
+ if (!FinishBlock(LHSBlock))
+ return 0;
+
+ Succ = ConfluenceBlock;
+ Block = NULL;
+ CFGBlock* RHSBlock = addStmt(C->getRHS());
+ if (!FinishBlock(RHSBlock))
+ return 0;
+
+ Block = createBlock(false);
+ // See if this is a known constant.
+ const TryResult& KnownVal = TryEvaluateBool(C->getCond());
+ AddSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock);
+ AddSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock);
+ Block->setTerminator(C);
+ return addStmt(C->getCond());
+}
+
+
+CFGBlock* CFGBuilder::VisitCompoundStmt(CompoundStmt* C) {
+ EndScope(C);
+
+ CFGBlock* LastBlock = Block;
+
+ for (CompoundStmt::reverse_body_iterator I=C->body_rbegin(), E=C->body_rend();
+ I != E; ++I ) {
+ LastBlock = addStmt(*I);
+
+ if (badCFG)
+ return NULL;
+ }
+
+ LastBlock = StartScope(C, LastBlock);
+
+ return LastBlock;
+}
+
+CFGBlock *CFGBuilder::VisitConditionalOperator(ConditionalOperator *C,
+ AddStmtChoice asc) {
+ // Create the confluence block that will "merge" the results of the ternary
+ // expression.
+ CFGBlock* ConfluenceBlock = Block ? Block : createBlock();
+ AppendStmt(ConfluenceBlock, C, asc);
+ if (!FinishBlock(ConfluenceBlock))
+ return 0;
+
+ // Create a block for the LHS expression if there is an LHS expression. A
+ // GCC extension allows LHS to be NULL, causing the condition to be the
+ // value that is returned instead.
+ // e.g: x ?: y is shorthand for: x ? x : y;
+ Succ = ConfluenceBlock;
+ Block = NULL;
+ CFGBlock* LHSBlock = NULL;
+ if (C->getLHS()) {
+ LHSBlock = addStmt(C->getLHS());
+ if (!FinishBlock(LHSBlock))
+ return 0;
+ Block = NULL;
+ }
+
+ // Create the block for the RHS expression.
+ Succ = ConfluenceBlock;
+ CFGBlock* RHSBlock = addStmt(C->getRHS());
+ if (!FinishBlock(RHSBlock))
+ return 0;
+
+ // Create the block that will contain the condition.
+ Block = createBlock(false);
+
+ // See if this is a known constant.
+ const TryResult& KnownVal = TryEvaluateBool(C->getCond());
+ if (LHSBlock) {
+ AddSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock);
+ } else {
+ if (KnownVal.isFalse()) {
+ // If we know the condition is false, add NULL as the successor for
+ // the block containing the condition. In this case, the confluence
+ // block will have just one predecessor.
+ AddSuccessor(Block, 0);
+ assert(ConfluenceBlock->pred_size() == 1);
+ } else {
+ // If we have no LHS expression, add the ConfluenceBlock as a direct
+ // successor for the block containing the condition. Moreover, we need to
+ // reverse the order of the predecessors in the ConfluenceBlock because
+ // the RHSBlock will have been added to the succcessors already, and we
+ // want the first predecessor to the the block containing the expression
+ // for the case when the ternary expression evaluates to true.
+ AddSuccessor(Block, ConfluenceBlock);
+ assert(ConfluenceBlock->pred_size() == 2);
+ std::reverse(ConfluenceBlock->pred_begin(),
+ ConfluenceBlock->pred_end());
+ }
+ }
+
+ AddSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock);
+ Block->setTerminator(C);
+ return addStmt(C->getCond());
+}
+
+CFGBlock *CFGBuilder::VisitDeclStmt(DeclStmt *DS) {
+ autoCreateBlock();
+
+ if (DS->isSingleDecl()) {
+ AppendStmt(Block, DS);
+ return VisitDeclSubExpr(DS->getSingleDecl());
+ }
+
+ CFGBlock *B = 0;
+
+ // FIXME: Add a reverse iterator for DeclStmt to avoid this extra copy.
+ typedef llvm::SmallVector<Decl*,10> BufTy;
+ BufTy Buf(DS->decl_begin(), DS->decl_end());
+
+ for (BufTy::reverse_iterator I = Buf.rbegin(), E = Buf.rend(); I != E; ++I) {
+ // Get the alignment of the new DeclStmt, padding out to >=8 bytes.
+ unsigned A = llvm::AlignOf<DeclStmt>::Alignment < 8
+ ? 8 : llvm::AlignOf<DeclStmt>::Alignment;
+
+ // Allocate the DeclStmt using the BumpPtrAllocator. It will get
+ // automatically freed with the CFG.
+ DeclGroupRef DG(*I);
+ Decl *D = *I;
+ void *Mem = cfg->getAllocator().Allocate(sizeof(DeclStmt), A);
+ DeclStmt *DSNew = new (Mem) DeclStmt(DG, D->getLocation(), GetEndLoc(D));
+
+ // Append the fake DeclStmt to block.
+ AppendStmt(Block, DSNew);
+ B = VisitDeclSubExpr(D);
+ }
+
+ return B;
+}
+
+/// VisitDeclSubExpr - Utility method to add block-level expressions for
+/// initializers in Decls.
+CFGBlock *CFGBuilder::VisitDeclSubExpr(Decl* D) {
+ assert(Block);
+
+ VarDecl *VD = dyn_cast<VarDecl>(D);
+
+ if (!VD)
+ return Block;
+
+ Expr *Init = VD->getInit();
+
+ if (Init) {
+ // Optimization: Don't create separate block-level statements for literals.
+ switch (Init->getStmtClass()) {
+ case Stmt::IntegerLiteralClass:
+ case Stmt::CharacterLiteralClass:
+ case Stmt::StringLiteralClass:
+ break;
+ default:
+ Block = addStmt(Init,
+ VD->getType()->isReferenceType()
+ ? AddStmtChoice::AlwaysAddAsLValue
+ : AddStmtChoice::AlwaysAdd);
+ }
+ }
+
+ // If the type of VD is a VLA, then we must process its size expressions.
+ for (VariableArrayType* VA = FindVA(VD->getType().getTypePtr()); VA != 0;
+ VA = FindVA(VA->getElementType().getTypePtr()))
+ Block = addStmt(VA->getSizeExpr());
+
+ return Block;
+}
+
+CFGBlock* CFGBuilder::VisitIfStmt(IfStmt* I) {
+ // We may see an if statement in the middle of a basic block, or it may be the
+ // first statement we are processing. In either case, we create a new basic
+ // block. First, we create the blocks for the then...else statements, and
+ // then we create the block containing the if statement. If we were in the
+ // middle of a block, we stop processing that block. That block is then the
+ // implicit successor for the "then" and "else" clauses.
+
+ // The block we were proccessing is now finished. Make it the successor
+ // block.
+ if (Block) {
+ Succ = Block;
+ if (!FinishBlock(Block))
+ return 0;
+ }
+
+ // Process the false branch.
+ CFGBlock* ElseBlock = Succ;
+
+ if (Stmt* Else = I->getElse()) {
+ SaveAndRestore<CFGBlock*> sv(Succ);
+
+ // NULL out Block so that the recursive call to Visit will
+ // create a new basic block.
+ Block = NULL;
+ ElseBlock = addStmt(Else);
+
+ if (!ElseBlock) // Can occur when the Else body has all NullStmts.
+ ElseBlock = sv.get();
+ else if (Block) {
+ if (!FinishBlock(ElseBlock))
+ return 0;
+ }
+ }
+
+ // Process the true branch.
+ CFGBlock* ThenBlock;
+ {
+ Stmt* Then = I->getThen();
+ assert(Then);
+ SaveAndRestore<CFGBlock*> sv(Succ);
+ Block = NULL;
+ ThenBlock = addStmt(Then);
+
+ if (!ThenBlock) {
+ // We can reach here if the "then" body has all NullStmts.
+ // Create an empty block so we can distinguish between true and false
+ // branches in path-sensitive analyses.
+ ThenBlock = createBlock(false);
+ AddSuccessor(ThenBlock, sv.get());
+ } else if (Block) {
+ if (!FinishBlock(ThenBlock))
+ return 0;
+ }
+ }
+
+ // Now create a new block containing the if statement.
+ Block = createBlock(false);
+
+ // Set the terminator of the new block to the If statement.
+ Block->setTerminator(I);
+
+ // See if this is a known constant.
+ const TryResult &KnownVal = TryEvaluateBool(I->getCond());
+
+ // Now add the successors.
+ AddSuccessor(Block, KnownVal.isFalse() ? NULL : ThenBlock);
+ AddSuccessor(Block, KnownVal.isTrue()? NULL : ElseBlock);
+
+ // Add the condition as the last statement in the new block. This may create
+ // new blocks as the condition may contain control-flow. Any newly created
+ // blocks will be pointed to be "Block".
+ Block = addStmt(I->getCond());
+
+ // Finally, if the IfStmt contains a condition variable, add both the IfStmt
+ // and the condition variable initialization to the CFG.
+ if (VarDecl *VD = I->getConditionVariable()) {
+ if (Expr *Init = VD->getInit()) {
+ autoCreateBlock();
+ AppendStmt(Block, I, AddStmtChoice::AlwaysAdd);
+ addStmt(Init);
+ }
+ }
+
+ return Block;
+}
+
+
+CFGBlock* CFGBuilder::VisitReturnStmt(ReturnStmt* R) {
+ // If we were in the middle of a block we stop processing that block.
+ //
+ // NOTE: If a "return" appears in the middle of a block, this means that the
+ // code afterwards is DEAD (unreachable). We still keep a basic block
+ // for that code; a simple "mark-and-sweep" from the entry block will be
+ // able to report such dead blocks.
+ if (Block)
+ FinishBlock(Block);
+
+ // Create the new block.
+ Block = createBlock(false);
+
+ // The Exit block is the only successor.
+ AddSuccessor(Block, &cfg->getExit());
+
+ // Add the return statement to the block. This may create new blocks if R
+ // contains control-flow (short-circuit operations).
+ return VisitStmt(R, AddStmtChoice::AlwaysAdd);
+}
+
+CFGBlock* CFGBuilder::VisitLabelStmt(LabelStmt* L) {
+ // Get the block of the labeled statement. Add it to our map.
+ addStmt(L->getSubStmt());
+ CFGBlock* LabelBlock = Block;
+
+ if (!LabelBlock) // This can happen when the body is empty, i.e.
+ LabelBlock = createBlock(); // scopes that only contains NullStmts.
+
+ assert(LabelMap.find(L) == LabelMap.end() && "label already in map");
+ LabelMap[ L ] = LabelBlock;
+
+ // Labels partition blocks, so this is the end of the basic block we were
+ // processing (L is the block's label). Because this is label (and we have
+ // already processed the substatement) there is no extra control-flow to worry
+ // about.
+ LabelBlock->setLabel(L);
+ if (!FinishBlock(LabelBlock))
+ return 0;
+
+ // We set Block to NULL to allow lazy creation of a new block (if necessary);
+ Block = NULL;
+
+ // This block is now the implicit successor of other blocks.
+ Succ = LabelBlock;
+
+ return LabelBlock;
+}
+
+CFGBlock* CFGBuilder::VisitGotoStmt(GotoStmt* G) {
+ // Goto is a control-flow statement. Thus we stop processing the current
+ // block and create a new one.
+ if (Block)
+ FinishBlock(Block);
+
+ Block = createBlock(false);
+ Block->setTerminator(G);
+
+ // If we already know the mapping to the label block add the successor now.
+ LabelMapTy::iterator I = LabelMap.find(G->getLabel());
+
+ if (I == LabelMap.end())
+ // We will need to backpatch this block later.
+ BackpatchBlocks.push_back(Block);
+ else
+ AddSuccessor(Block, I->second);
+
+ return Block;
+}
+
+CFGBlock* CFGBuilder::VisitForStmt(ForStmt* F) {
+ CFGBlock* LoopSuccessor = NULL;
+
+ // "for" is a control-flow statement. Thus we stop processing the current
+ // block.
+ if (Block) {
+ if (!FinishBlock(Block))
+ return 0;
+ LoopSuccessor = Block;
+ } else
+ LoopSuccessor = Succ;
+
+ // Because of short-circuit evaluation, the condition of the loop can span
+ // multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that
+ // evaluate the condition.
+ CFGBlock* ExitConditionBlock = createBlock(false);
+ CFGBlock* EntryConditionBlock = ExitConditionBlock;
+
+ // Set the terminator for the "exit" condition block.
+ ExitConditionBlock->setTerminator(F);
+
+ // Now add the actual condition to the condition block. Because the condition
+ // itself may contain control-flow, new blocks may be created.
+ if (Stmt* C = F->getCond()) {
+ Block = ExitConditionBlock;
+ EntryConditionBlock = addStmt(C);
+ assert(Block == EntryConditionBlock);
+
+ // If this block contains a condition variable, add both the condition
+ // variable and initializer to the CFG.
+ if (VarDecl *VD = F->getConditionVariable()) {
+ if (Expr *Init = VD->getInit()) {
+ autoCreateBlock();
+ AppendStmt(Block, F, AddStmtChoice::AlwaysAdd);
+ EntryConditionBlock = addStmt(Init);
+ assert(Block == EntryConditionBlock);
+ }
+ }
+
+ if (Block) {
+ if (!FinishBlock(EntryConditionBlock))
+ return 0;
+ }
+ }
+
+ // The condition block is the implicit successor for the loop body as well as
+ // any code above the loop.
+ Succ = EntryConditionBlock;
+
+ // See if this is a known constant.
+ TryResult KnownVal(true);
+
+ if (F->getCond())
+ KnownVal = TryEvaluateBool(F->getCond());
+
+ // Now create the loop body.
+ {
+ assert(F->getBody());
+
+ // Save the current values for Block, Succ, and continue and break targets
+ SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ),
+ save_continue(ContinueTargetBlock),
+ save_break(BreakTargetBlock);
+
+ // Create a new block to contain the (bottom) of the loop body.
+ Block = NULL;
+
+ if (Stmt* I = F->getInc()) {
+ // Generate increment code in its own basic block. This is the target of
+ // continue statements.
+ Succ = addStmt(I);
+ } else {
+ // No increment code. Create a special, empty, block that is used as the
+ // target block for "looping back" to the start of the loop.
+ assert(Succ == EntryConditionBlock);
+ Succ = createBlock();
+ }
+
+ // Finish up the increment (or empty) block if it hasn't been already.
+ if (Block) {
+ assert(Block == Succ);
+ if (!FinishBlock(Block))
+ return 0;
+ Block = 0;
+ }
+
+ ContinueTargetBlock = Succ;
+
+ // The starting block for the loop increment is the block that should
+ // represent the 'loop target' for looping back to the start of the loop.
+ ContinueTargetBlock->setLoopTarget(F);
+
+ // All breaks should go to the code following the loop.
+ BreakTargetBlock = LoopSuccessor;
+
+ // Now populate the body block, and in the process create new blocks as we
+ // walk the body of the loop.
+ CFGBlock* BodyBlock = addStmt(F->getBody());
+
+ if (!BodyBlock)
+ BodyBlock = ContinueTargetBlock; // can happen for "for (...;...;...) ;"
+ else if (Block && !FinishBlock(BodyBlock))
+ return 0;
+
+ // This new body block is a successor to our "exit" condition block.
+ AddSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock);
+ }
+
+ // Link up the condition block with the code that follows the loop. (the
+ // false branch).
+ AddSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
+
+ // If the loop contains initialization, create a new block for those
+ // statements. This block can also contain statements that precede the loop.
+ if (Stmt* I = F->getInit()) {
+ Block = createBlock();
+ return addStmt(I);
+ } else {
+ // There is no loop initialization. We are thus basically a while loop.
+ // NULL out Block to force lazy block construction.
+ Block = NULL;
+ Succ = EntryConditionBlock;
+ return EntryConditionBlock;
+ }
+}
+
+CFGBlock* CFGBuilder::VisitObjCForCollectionStmt(ObjCForCollectionStmt* S) {
+ // Objective-C fast enumeration 'for' statements:
+ // http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC
+ //
+ // for ( Type newVariable in collection_expression ) { statements }
+ //
+ // becomes:
+ //
+ // prologue:
+ // 1. collection_expression
+ // T. jump to loop_entry
+ // loop_entry:
+ // 1. side-effects of element expression
+ // 1. ObjCForCollectionStmt [performs binding to newVariable]
+ // T. ObjCForCollectionStmt TB, FB [jumps to TB if newVariable != nil]
+ // TB:
+ // statements
+ // T. jump to loop_entry
+ // FB:
+ // what comes after
+ //
+ // and
+ //
+ // Type existingItem;
+ // for ( existingItem in expression ) { statements }
+ //
+ // becomes:
+ //
+ // the same with newVariable replaced with existingItem; the binding works
+ // the same except that for one ObjCForCollectionStmt::getElement() returns
+ // a DeclStmt and the other returns a DeclRefExpr.
+ //
+
+ CFGBlock* LoopSuccessor = 0;
+
+ if (Block) {
+ if (!FinishBlock(Block))
+ return 0;
+ LoopSuccessor = Block;
+ Block = 0;
+ } else
+ LoopSuccessor = Succ;
+
+ // Build the condition blocks.
+ CFGBlock* ExitConditionBlock = createBlock(false);
+ CFGBlock* EntryConditionBlock = ExitConditionBlock;
+
+ // Set the terminator for the "exit" condition block.
+ ExitConditionBlock->setTerminator(S);
+
+ // The last statement in the block should be the ObjCForCollectionStmt, which
+ // performs the actual binding to 'element' and determines if there are any
+ // more items in the collection.
+ AppendStmt(ExitConditionBlock, S);
+ Block = ExitConditionBlock;
+
+ // Walk the 'element' expression to see if there are any side-effects. We
+ // generate new blocks as necesary. We DON'T add the statement by default to
+ // the CFG unless it contains control-flow.
+ EntryConditionBlock = Visit(S->getElement(), AddStmtChoice::NotAlwaysAdd);
+ if (Block) {
+ if (!FinishBlock(EntryConditionBlock))
+ return 0;
+ Block = 0;
+ }
+
+ // The condition block is the implicit successor for the loop body as well as
+ // any code above the loop.
+ Succ = EntryConditionBlock;
+
+ // Now create the true branch.
+ {
+ // Save the current values for Succ, continue and break targets.
+ SaveAndRestore<CFGBlock*> save_Succ(Succ),
+ save_continue(ContinueTargetBlock), save_break(BreakTargetBlock);
+
+ BreakTargetBlock = LoopSuccessor;
+ ContinueTargetBlock = EntryConditionBlock;
+
+ CFGBlock* BodyBlock = addStmt(S->getBody());
+
+ if (!BodyBlock)
+ BodyBlock = EntryConditionBlock; // can happen for "for (X in Y) ;"
+ else if (Block) {
+ if (!FinishBlock(BodyBlock))
+ return 0;
+ }
+
+ // This new body block is a successor to our "exit" condition block.
+ AddSuccessor(ExitConditionBlock, BodyBlock);
+ }
+
+ // Link up the condition block with the code that follows the loop.
+ // (the false branch).
+ AddSuccessor(ExitConditionBlock, LoopSuccessor);
+
+ // Now create a prologue block to contain the collection expression.
+ Block = createBlock();
+ return addStmt(S->getCollection());
+}
+
+CFGBlock* CFGBuilder::VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt* S) {
+ // FIXME: Add locking 'primitives' to CFG for @synchronized.
+
+ // Inline the body.
+ CFGBlock *SyncBlock = addStmt(S->getSynchBody());
+
+ // The sync body starts its own basic block. This makes it a little easier
+ // for diagnostic clients.
+ if (SyncBlock) {
+ if (!FinishBlock(SyncBlock))
+ return 0;
+
+ Block = 0;
+ }
+
+ Succ = SyncBlock;
+
+ // Inline the sync expression.
+ return addStmt(S->getSynchExpr());
+}
+
+CFGBlock* CFGBuilder::VisitObjCAtTryStmt(ObjCAtTryStmt* S) {
+ // FIXME
+ return NYS();
+}
+
+CFGBlock* CFGBuilder::VisitWhileStmt(WhileStmt* W) {
+ CFGBlock* LoopSuccessor = NULL;
+
+ // "while" is a control-flow statement. Thus we stop processing the current
+ // block.
+ if (Block) {
+ if (!FinishBlock(Block))
+ return 0;
+ LoopSuccessor = Block;
+ } else
+ LoopSuccessor = Succ;
+
+ // Because of short-circuit evaluation, the condition of the loop can span
+ // multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that
+ // evaluate the condition.
+ CFGBlock* ExitConditionBlock = createBlock(false);
+ CFGBlock* EntryConditionBlock = ExitConditionBlock;
+
+ // Set the terminator for the "exit" condition block.
+ ExitConditionBlock->setTerminator(W);
+
+ // Now add the actual condition to the condition block. Because the condition
+ // itself may contain control-flow, new blocks may be created. Thus we update
+ // "Succ" after adding the condition.
+ if (Stmt* C = W->getCond()) {
+ Block = ExitConditionBlock;
+ EntryConditionBlock = addStmt(C);
+ assert(Block == EntryConditionBlock);
+
+ // If this block contains a condition variable, add both the condition
+ // variable and initializer to the CFG.
+ if (VarDecl *VD = W->getConditionVariable()) {
+ if (Expr *Init = VD->getInit()) {
+ autoCreateBlock();
+ AppendStmt(Block, W, AddStmtChoice::AlwaysAdd);
+ EntryConditionBlock = addStmt(Init);
+ assert(Block == EntryConditionBlock);
+ }
+ }
+
+ if (Block) {
+ if (!FinishBlock(EntryConditionBlock))
+ return 0;
+ }
+ }
+
+ // The condition block is the implicit successor for the loop body as well as
+ // any code above the loop.
+ Succ = EntryConditionBlock;
+
+ // See if this is a known constant.
+ const TryResult& KnownVal = TryEvaluateBool(W->getCond());
+
+ // Process the loop body.
+ {
+ assert(W->getBody());
+
+ // Save the current values for Block, Succ, and continue and break targets
+ SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ),
+ save_continue(ContinueTargetBlock),
+ save_break(BreakTargetBlock);
+
+ // Create an empty block to represent the transition block for looping back
+ // to the head of the loop.
+ Block = 0;
+ assert(Succ == EntryConditionBlock);
+ Succ = createBlock();
+ Succ->setLoopTarget(W);
+ ContinueTargetBlock = Succ;
+
+ // All breaks should go to the code following the loop.
+ BreakTargetBlock = LoopSuccessor;
+
+ // NULL out Block to force lazy instantiation of blocks for the body.
+ Block = NULL;
+
+ // Create the body. The returned block is the entry to the loop body.
+ CFGBlock* BodyBlock = addStmt(W->getBody());
+
+ if (!BodyBlock)
+ BodyBlock = ContinueTargetBlock; // can happen for "while(...) ;"
+ else if (Block) {
+ if (!FinishBlock(BodyBlock))
+ return 0;
+ }
+
+ // Add the loop body entry as a successor to the condition.
+ AddSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock);
+ }
+
+ // Link up the condition block with the code that follows the loop. (the
+ // false branch).
+ AddSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
+
+ // There can be no more statements in the condition block since we loop back
+ // to this block. NULL out Block to force lazy creation of another block.
+ Block = NULL;
+
+ // Return the condition block, which is the dominating block for the loop.
+ Succ = EntryConditionBlock;
+ return EntryConditionBlock;
+}
+
+
+CFGBlock *CFGBuilder::VisitObjCAtCatchStmt(ObjCAtCatchStmt* S) {
+ // FIXME: For now we pretend that @catch and the code it contains does not
+ // exit.
+ return Block;
+}
+
+CFGBlock* CFGBuilder::VisitObjCAtThrowStmt(ObjCAtThrowStmt* S) {
+ // FIXME: This isn't complete. We basically treat @throw like a return
+ // statement.
+
+ // If we were in the middle of a block we stop processing that block.
+ if (Block && !FinishBlock(Block))
+ return 0;
+
+ // Create the new block.
+ Block = createBlock(false);
+
+ // The Exit block is the only successor.
+ AddSuccessor(Block, &cfg->getExit());
+
+ // Add the statement to the block. This may create new blocks if S contains
+ // control-flow (short-circuit operations).
+ return VisitStmt(S, AddStmtChoice::AlwaysAdd);
+}
+
+CFGBlock* CFGBuilder::VisitCXXThrowExpr(CXXThrowExpr* T) {
+ // If we were in the middle of a block we stop processing that block.
+ if (Block && !FinishBlock(Block))
+ return 0;
+
+ // Create the new block.
+ Block = createBlock(false);
+
+ if (TryTerminatedBlock)
+ // The current try statement is the only successor.
+ AddSuccessor(Block, TryTerminatedBlock);
+ else
+ // otherwise the Exit block is the only successor.
+ AddSuccessor(Block, &cfg->getExit());
+
+ // Add the statement to the block. This may create new blocks if S contains
+ // control-flow (short-circuit operations).
+ return VisitStmt(T, AddStmtChoice::AlwaysAdd);
+}
+
+CFGBlock *CFGBuilder::VisitDoStmt(DoStmt* D) {
+ CFGBlock* LoopSuccessor = NULL;
+
+ // "do...while" is a control-flow statement. Thus we stop processing the
+ // current block.
+ if (Block) {
+ if (!FinishBlock(Block))
+ return 0;
+ LoopSuccessor = Block;
+ } else
+ LoopSuccessor = Succ;
+
+ // Because of short-circuit evaluation, the condition of the loop can span
+ // multiple basic blocks. Thus we need the "Entry" and "Exit" blocks that
+ // evaluate the condition.
+ CFGBlock* ExitConditionBlock = createBlock(false);
+ CFGBlock* EntryConditionBlock = ExitConditionBlock;
+
+ // Set the terminator for the "exit" condition block.
+ ExitConditionBlock->setTerminator(D);
+
+ // Now add the actual condition to the condition block. Because the condition
+ // itself may contain control-flow, new blocks may be created.
+ if (Stmt* C = D->getCond()) {
+ Block = ExitConditionBlock;
+ EntryConditionBlock = addStmt(C);
+ if (Block) {
+ if (!FinishBlock(EntryConditionBlock))
+ return 0;
+ }
+ }
+
+ // The condition block is the implicit successor for the loop body.
+ Succ = EntryConditionBlock;
+
+ // See if this is a known constant.
+ const TryResult &KnownVal = TryEvaluateBool(D->getCond());
+
+ // Process the loop body.
+ CFGBlock* BodyBlock = NULL;
+ {
+ assert(D->getBody());
+
+ // Save the current values for Block, Succ, and continue and break targets
+ SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ),
+ save_continue(ContinueTargetBlock),
+ save_break(BreakTargetBlock);
+
+ // All continues within this loop should go to the condition block
+ ContinueTargetBlock = EntryConditionBlock;
+
+ // All breaks should go to the code following the loop.
+ BreakTargetBlock = LoopSuccessor;
+
+ // NULL out Block to force lazy instantiation of blocks for the body.
+ Block = NULL;
+
+ // Create the body. The returned block is the entry to the loop body.
+ BodyBlock = addStmt(D->getBody());
+
+ if (!BodyBlock)
+ BodyBlock = EntryConditionBlock; // can happen for "do ; while(...)"
+ else if (Block) {
+ if (!FinishBlock(BodyBlock))
+ return 0;
+ }
+
+ // Add an intermediate block between the BodyBlock and the
+ // ExitConditionBlock to represent the "loop back" transition. Create an
+ // empty block to represent the transition block for looping back to the
+ // head of the loop.
+ // FIXME: Can we do this more efficiently without adding another block?
+ Block = NULL;
+ Succ = BodyBlock;
+ CFGBlock *LoopBackBlock = createBlock();
+ LoopBackBlock->setLoopTarget(D);
+
+ // Add the loop body entry as a successor to the condition.
+ AddSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : LoopBackBlock);
+ }
+
+ // Link up the condition block with the code that follows the loop.
+ // (the false branch).
+ AddSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
+
+ // There can be no more statements in the body block(s) since we loop back to
+ // the body. NULL out Block to force lazy creation of another block.
+ Block = NULL;
+
+ // Return the loop body, which is the dominating block for the loop.
+ Succ = BodyBlock;
+ return BodyBlock;
+}
+
+CFGBlock* CFGBuilder::VisitContinueStmt(ContinueStmt* C) {
+ // "continue" is a control-flow statement. Thus we stop processing the
+ // current block.
+ if (Block && !FinishBlock(Block))
+ return 0;
+
+ // Now create a new block that ends with the continue statement.
+ Block = createBlock(false);
+ Block->setTerminator(C);
+
+ // If there is no target for the continue, then we are looking at an
+ // incomplete AST. This means the CFG cannot be constructed.
+ if (ContinueTargetBlock)
+ AddSuccessor(Block, ContinueTargetBlock);
+ else
+ badCFG = true;
+
+ return Block;
+}
+
+CFGBlock *CFGBuilder::VisitSizeOfAlignOfExpr(SizeOfAlignOfExpr *E,
+ AddStmtChoice asc) {
+
+ if (asc.alwaysAdd()) {
+ autoCreateBlock();
+ AppendStmt(Block, E);
+ }
+
+ // VLA types have expressions that must be evaluated.
+ if (E->isArgumentType()) {
+ for (VariableArrayType* VA = FindVA(E->getArgumentType().getTypePtr());
+ VA != 0; VA = FindVA(VA->getElementType().getTypePtr()))
+ addStmt(VA->getSizeExpr());
+ }
+
+ return Block;
+}
+
+/// VisitStmtExpr - Utility method to handle (nested) statement
+/// expressions (a GCC extension).
+CFGBlock* CFGBuilder::VisitStmtExpr(StmtExpr *SE, AddStmtChoice asc) {
+ if (asc.alwaysAdd()) {
+ autoCreateBlock();
+ AppendStmt(Block, SE);
+ }
+ return VisitCompoundStmt(SE->getSubStmt());
+}
+
+CFGBlock* CFGBuilder::VisitSwitchStmt(SwitchStmt* Terminator) {
+ // "switch" is a control-flow statement. Thus we stop processing the current
+ // block.
+ CFGBlock* SwitchSuccessor = NULL;
+
+ if (Block) {
+ if (!FinishBlock(Block))
+ return 0;
+ SwitchSuccessor = Block;
+ } else SwitchSuccessor = Succ;
+
+ // Save the current "switch" context.
+ SaveAndRestore<CFGBlock*> save_switch(SwitchTerminatedBlock),
+ save_break(BreakTargetBlock),
+ save_default(DefaultCaseBlock);
+
+ // Set the "default" case to be the block after the switch statement. If the
+ // switch statement contains a "default:", this value will be overwritten with
+ // the block for that code.
+ DefaultCaseBlock = SwitchSuccessor;
+
+ // Create a new block that will contain the switch statement.
+ SwitchTerminatedBlock = createBlock(false);
+
+ // Now process the switch body. The code after the switch is the implicit
+ // successor.
+ Succ = SwitchSuccessor;
+ BreakTargetBlock = SwitchSuccessor;
+
+ // When visiting the body, the case statements should automatically get linked
+ // up to the switch. We also don't keep a pointer to the body, since all
+ // control-flow from the switch goes to case/default statements.
+ assert(Terminator->getBody() && "switch must contain a non-NULL body");
+ Block = NULL;
+ CFGBlock *BodyBlock = addStmt(Terminator->getBody());
+ if (Block) {
+ if (!FinishBlock(BodyBlock))
+ return 0;
+ }
+
+ // If we have no "default:" case, the default transition is to the code
+ // following the switch body.
+ AddSuccessor(SwitchTerminatedBlock, DefaultCaseBlock);
+
+ // Add the terminator and condition in the switch block.
+ SwitchTerminatedBlock->setTerminator(Terminator);
+ assert(Terminator->getCond() && "switch condition must be non-NULL");
+ Block = SwitchTerminatedBlock;
+ Block = addStmt(Terminator->getCond());
+
+ // Finally, if the SwitchStmt contains a condition variable, add both the
+ // SwitchStmt and the condition variable initialization to the CFG.
+ if (VarDecl *VD = Terminator->getConditionVariable()) {
+ if (Expr *Init = VD->getInit()) {
+ autoCreateBlock();
+ AppendStmt(Block, Terminator, AddStmtChoice::AlwaysAdd);
+ addStmt(Init);
+ }
+ }
+
+ return Block;
+}
+
+CFGBlock* CFGBuilder::VisitCaseStmt(CaseStmt* CS) {
+ // CaseStmts are essentially labels, so they are the first statement in a
+ // block.
+
+ if (CS->getSubStmt())
+ addStmt(CS->getSubStmt());
+
+ CFGBlock* CaseBlock = Block;
+ if (!CaseBlock)
+ CaseBlock = createBlock();
+
+ // Cases statements partition blocks, so this is the top of the basic block we
+ // were processing (the "case XXX:" is the label).
+ CaseBlock->setLabel(CS);
+
+ if (!FinishBlock(CaseBlock))
+ return 0;
+
+ // Add this block to the list of successors for the block with the switch
+ // statement.
+ assert(SwitchTerminatedBlock);
+ AddSuccessor(SwitchTerminatedBlock, CaseBlock);
+
+ // We set Block to NULL to allow lazy creation of a new block (if necessary)
+ Block = NULL;
+
+ // This block is now the implicit successor of other blocks.
+ Succ = CaseBlock;
+
+ return CaseBlock;
+}
+
+CFGBlock* CFGBuilder::VisitDefaultStmt(DefaultStmt* Terminator) {
+ if (Terminator->getSubStmt())
+ addStmt(Terminator->getSubStmt());
+
+ DefaultCaseBlock = Block;
+
+ if (!DefaultCaseBlock)
+ DefaultCaseBlock = createBlock();
+
+ // Default statements partition blocks, so this is the top of the basic block
+ // we were processing (the "default:" is the label).
+ DefaultCaseBlock->setLabel(Terminator);
+
+ if (!FinishBlock(DefaultCaseBlock))
+ return 0;
+
+ // Unlike case statements, we don't add the default block to the successors
+ // for the switch statement immediately. This is done when we finish
+ // processing the switch statement. This allows for the default case
+ // (including a fall-through to the code after the switch statement) to always
+ // be the last successor of a switch-terminated block.
+
+ // We set Block to NULL to allow lazy creation of a new block (if necessary)
+ Block = NULL;
+
+ // This block is now the implicit successor of other blocks.
+ Succ = DefaultCaseBlock;
+
+ return DefaultCaseBlock;
+}
+
+CFGBlock *CFGBuilder::VisitCXXTryStmt(CXXTryStmt *Terminator) {
+ // "try"/"catch" is a control-flow statement. Thus we stop processing the
+ // current block.
+ CFGBlock* TrySuccessor = NULL;
+
+ if (Block) {
+ if (!FinishBlock(Block))
+ return 0;
+ TrySuccessor = Block;
+ } else TrySuccessor = Succ;
+
+ CFGBlock *PrevTryTerminatedBlock = TryTerminatedBlock;
+
+ // Create a new block that will contain the try statement.
+ CFGBlock *NewTryTerminatedBlock = createBlock(false);
+ // Add the terminator in the try block.
+ NewTryTerminatedBlock->setTerminator(Terminator);
+
+ bool HasCatchAll = false;
+ for (unsigned h = 0; h <Terminator->getNumHandlers(); ++h) {
+ // The code after the try is the implicit successor.
+ Succ = TrySuccessor;
+ CXXCatchStmt *CS = Terminator->getHandler(h);
+ if (CS->getExceptionDecl() == 0) {
+ HasCatchAll = true;
+ }
+ Block = NULL;
+ CFGBlock *CatchBlock = VisitCXXCatchStmt(CS);
+ if (CatchBlock == 0)
+ return 0;
+ // Add this block to the list of successors for the block with the try
+ // statement.
+ AddSuccessor(NewTryTerminatedBlock, CatchBlock);
+ }
+ if (!HasCatchAll) {
+ if (PrevTryTerminatedBlock)
+ AddSuccessor(NewTryTerminatedBlock, PrevTryTerminatedBlock);
+ else
+ AddSuccessor(NewTryTerminatedBlock, &cfg->getExit());
+ }
+
+ // The code after the try is the implicit successor.
+ Succ = TrySuccessor;
+
+ // Save the current "try" context.
+ SaveAndRestore<CFGBlock*> save_try(TryTerminatedBlock);
+ TryTerminatedBlock = NewTryTerminatedBlock;
+
+ assert(Terminator->getTryBlock() && "try must contain a non-NULL body");
+ Block = NULL;
+ Block = addStmt(Terminator->getTryBlock());
+ return Block;
+}
+
+CFGBlock* CFGBuilder::VisitCXXCatchStmt(CXXCatchStmt* CS) {
+ // CXXCatchStmt are treated like labels, so they are the first statement in a
+ // block.
+
+ if (CS->getHandlerBlock())
+ addStmt(CS->getHandlerBlock());
+
+ CFGBlock* CatchBlock = Block;
+ if (!CatchBlock)
+ CatchBlock = createBlock();
+
+ CatchBlock->setLabel(CS);
+
+ if (!FinishBlock(CatchBlock))
+ return 0;
+
+ // We set Block to NULL to allow lazy creation of a new block (if necessary)
+ Block = NULL;
+
+ return CatchBlock;
+}
+
+CFGBlock* CFGBuilder::VisitIndirectGotoStmt(IndirectGotoStmt* I) {
+ // Lazily create the indirect-goto dispatch block if there isn't one already.
+ CFGBlock* IBlock = cfg->getIndirectGotoBlock();
+
+ if (!IBlock) {
+ IBlock = createBlock(false);
+ cfg->setIndirectGotoBlock(IBlock);
+ }
+
+ // IndirectGoto is a control-flow statement. Thus we stop processing the
+ // current block and create a new one.
+ if (Block && !FinishBlock(Block))
+ return 0;
+
+ Block = createBlock(false);
+ Block->setTerminator(I);
+ AddSuccessor(Block, IBlock);
+ return addStmt(I->getTarget());
+}
+
+} // end anonymous namespace
+
+/// createBlock - Constructs and adds a new CFGBlock to the CFG. The block has
+/// no successors or predecessors. If this is the first block created in the
+/// CFG, it is automatically set to be the Entry and Exit of the CFG.
+CFGBlock* CFG::createBlock() {
+ bool first_block = begin() == end();
+
+ // Create the block.
+ CFGBlock *Mem = getAllocator().Allocate<CFGBlock>();
+ new (Mem) CFGBlock(NumBlockIDs++, BlkBVC);
+ Blocks.push_back(Mem, BlkBVC);
+
+ // If this is the first block, set it as the Entry and Exit.
+ if (first_block)
+ Entry = Exit = &back();
+
+ // Return the block.
+ return &back();
+}
+
+/// buildCFG - Constructs a CFG from an AST. Ownership of the returned
+/// CFG is returned to the caller.
+CFG* CFG::buildCFG(const Decl *D, Stmt* Statement, ASTContext *C,
+ bool AddEHEdges, bool AddScopes) {
+ CFGBuilder Builder;
+ return Builder.buildCFG(D, Statement, C, AddEHEdges, AddScopes);
+}
+
+//===----------------------------------------------------------------------===//
+// CFG: Queries for BlkExprs.
+//===----------------------------------------------------------------------===//
+
+namespace {
+ typedef llvm::DenseMap<const Stmt*,unsigned> BlkExprMapTy;
+}
+
+static void FindSubExprAssignments(Stmt *S,
+ llvm::SmallPtrSet<Expr*,50>& Set) {
+ if (!S)
+ return;
+
+ for (Stmt::child_iterator I=S->child_begin(), E=S->child_end(); I!=E; ++I) {
+ Stmt *child = *I;
+ if (!child)
+ continue;
+
+ if (BinaryOperator* B = dyn_cast<BinaryOperator>(child))
+ if (B->isAssignmentOp()) Set.insert(B);
+
+ FindSubExprAssignments(child, Set);
+ }
+}
+
+static BlkExprMapTy* PopulateBlkExprMap(CFG& cfg) {
+ BlkExprMapTy* M = new BlkExprMapTy();
+
+ // Look for assignments that are used as subexpressions. These are the only
+ // assignments that we want to *possibly* register as a block-level
+ // expression. Basically, if an assignment occurs both in a subexpression and
+ // at the block-level, it is a block-level expression.
+ llvm::SmallPtrSet<Expr*,50> SubExprAssignments;
+
+ for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I)
+ for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI)
+ FindSubExprAssignments(*BI, SubExprAssignments);
+
+ for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I) {
+
+ // Iterate over the statements again on identify the Expr* and Stmt* at the
+ // block-level that are block-level expressions.
+
+ for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI)
+ if (Expr* Exp = dyn_cast<Expr>(*BI)) {
+
+ if (BinaryOperator* B = dyn_cast<BinaryOperator>(Exp)) {
+ // Assignment expressions that are not nested within another
+ // expression are really "statements" whose value is never used by
+ // another expression.
+ if (B->isAssignmentOp() && !SubExprAssignments.count(Exp))
+ continue;
+ } else if (const StmtExpr* Terminator = dyn_cast<StmtExpr>(Exp)) {
+ // Special handling for statement expressions. The last statement in
+ // the statement expression is also a block-level expr.
+ const CompoundStmt* C = Terminator->getSubStmt();
+ if (!C->body_empty()) {
+ unsigned x = M->size();
+ (*M)[C->body_back()] = x;
+ }
+ }
+
+ unsigned x = M->size();
+ (*M)[Exp] = x;
+ }
+
+ // Look at terminators. The condition is a block-level expression.
+
+ Stmt* S = (*I)->getTerminatorCondition();
+
+ if (S && M->find(S) == M->end()) {
+ unsigned x = M->size();
+ (*M)[S] = x;
+ }
+ }
+
+ return M;
+}
+
+CFG::BlkExprNumTy CFG::getBlkExprNum(const Stmt* S) {
+ assert(S != NULL);
+ if (!BlkExprMap) { BlkExprMap = (void*) PopulateBlkExprMap(*this); }
+
+ BlkExprMapTy* M = reinterpret_cast<BlkExprMapTy*>(BlkExprMap);
+ BlkExprMapTy::iterator I = M->find(S);
+ return (I == M->end()) ? CFG::BlkExprNumTy() : CFG::BlkExprNumTy(I->second);
+}
+
+unsigned CFG::getNumBlkExprs() {
+ if (const BlkExprMapTy* M = reinterpret_cast<const BlkExprMapTy*>(BlkExprMap))
+ return M->size();
+ else {
+ // We assume callers interested in the number of BlkExprs will want
+ // the map constructed if it doesn't already exist.
+ BlkExprMap = (void*) PopulateBlkExprMap(*this);
+ return reinterpret_cast<BlkExprMapTy*>(BlkExprMap)->size();
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// Cleanup: CFG dstor.
+//===----------------------------------------------------------------------===//
+
+CFG::~CFG() {
+ delete reinterpret_cast<const BlkExprMapTy*>(BlkExprMap);
+}
+
+//===----------------------------------------------------------------------===//
+// CFG pretty printing
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+class StmtPrinterHelper : public PrinterHelper {
+ typedef llvm::DenseMap<Stmt*,std::pair<unsigned,unsigned> > StmtMapTy;
+ StmtMapTy StmtMap;
+ signed CurrentBlock;
+ unsigned CurrentStmt;
+ const LangOptions &LangOpts;
+public:
+
+ StmtPrinterHelper(const CFG* cfg, const LangOptions &LO)
+ : CurrentBlock(0), CurrentStmt(0), LangOpts(LO) {
+ for (CFG::const_iterator I = cfg->begin(), E = cfg->end(); I != E; ++I ) {
+ unsigned j = 1;
+ for (CFGBlock::const_iterator BI = (*I)->begin(), BEnd = (*I)->end() ;
+ BI != BEnd; ++BI, ++j )
+ StmtMap[*BI] = std::make_pair((*I)->getBlockID(),j);
+ }
+ }
+
+ virtual ~StmtPrinterHelper() {}
+
+ const LangOptions &getLangOpts() const { return LangOpts; }
+ void setBlockID(signed i) { CurrentBlock = i; }
+ void setStmtID(unsigned i) { CurrentStmt = i; }
+
+ virtual bool handledStmt(Stmt* Terminator, llvm::raw_ostream& OS) {
+
+ StmtMapTy::iterator I = StmtMap.find(Terminator);
+
+ if (I == StmtMap.end())
+ return false;
+
+ if (CurrentBlock >= 0 && I->second.first == (unsigned) CurrentBlock
+ && I->second.second == CurrentStmt) {
+ return false;
+ }
+
+ OS << "[B" << I->second.first << "." << I->second.second << "]";
+ return true;
+ }
+};
+} // end anonymous namespace
+
+
+namespace {
+class CFGBlockTerminatorPrint
+ : public StmtVisitor<CFGBlockTerminatorPrint,void> {
+
+ llvm::raw_ostream& OS;
+ StmtPrinterHelper* Helper;
+ PrintingPolicy Policy;
+public:
+ CFGBlockTerminatorPrint(llvm::raw_ostream& os, StmtPrinterHelper* helper,
+ const PrintingPolicy &Policy)
+ : OS(os), Helper(helper), Policy(Policy) {}
+
+ void VisitIfStmt(IfStmt* I) {
+ OS << "if ";
+ I->getCond()->printPretty(OS,Helper,Policy);
+ }
+
+ // Default case.
+ void VisitStmt(Stmt* Terminator) {
+ Terminator->printPretty(OS, Helper, Policy);
+ }
+
+ void VisitForStmt(ForStmt* F) {
+ OS << "for (" ;
+ if (F->getInit())
+ OS << "...";
+ OS << "; ";
+ if (Stmt* C = F->getCond())
+ C->printPretty(OS, Helper, Policy);
+ OS << "; ";
+ if (F->getInc())
+ OS << "...";
+ OS << ")";
+ }
+
+ void VisitWhileStmt(WhileStmt* W) {
+ OS << "while " ;
+ if (Stmt* C = W->getCond())
+ C->printPretty(OS, Helper, Policy);
+ }
+
+ void VisitDoStmt(DoStmt* D) {
+ OS << "do ... while ";
+ if (Stmt* C = D->getCond())
+ C->printPretty(OS, Helper, Policy);
+ }
+
+ void VisitSwitchStmt(SwitchStmt* Terminator) {
+ OS << "switch ";
+ Terminator->getCond()->printPretty(OS, Helper, Policy);
+ }
+
+ void VisitCXXTryStmt(CXXTryStmt* CS) {
+ OS << "try ...";
+ }
+
+ void VisitConditionalOperator(ConditionalOperator* C) {
+ C->getCond()->printPretty(OS, Helper, Policy);
+ OS << " ? ... : ...";
+ }
+
+ void VisitChooseExpr(ChooseExpr* C) {
+ OS << "__builtin_choose_expr( ";
+ C->getCond()->printPretty(OS, Helper, Policy);
+ OS << " )";
+ }
+
+ void VisitIndirectGotoStmt(IndirectGotoStmt* I) {
+ OS << "goto *";
+ I->getTarget()->printPretty(OS, Helper, Policy);
+ }
+
+ void VisitBinaryOperator(BinaryOperator* B) {
+ if (!B->isLogicalOp()) {
+ VisitExpr(B);
+ return;
+ }
+
+ B->getLHS()->printPretty(OS, Helper, Policy);
+
+ switch (B->getOpcode()) {
+ case BinaryOperator::LOr:
+ OS << " || ...";
+ return;
+ case BinaryOperator::LAnd:
+ OS << " && ...";
+ return;
+ default:
+ assert(false && "Invalid logical operator.");
+ }
+ }
+
+ void VisitExpr(Expr* E) {
+ E->printPretty(OS, Helper, Policy);
+ }
+};
+} // end anonymous namespace
+
+
+static void print_stmt(llvm::raw_ostream &OS, StmtPrinterHelper* Helper,
+ const CFGElement &E) {
+ Stmt *Terminator = E;
+
+ if (E.asStartScope()) {
+ OS << "start scope\n";
+ return;
+ }
+ if (E.asEndScope()) {
+ OS << "end scope\n";
+ return;
+ }
+
+ if (Helper) {
+ // special printing for statement-expressions.
+ if (StmtExpr* SE = dyn_cast<StmtExpr>(Terminator)) {
+ CompoundStmt* Sub = SE->getSubStmt();
+
+ if (Sub->child_begin() != Sub->child_end()) {
+ OS << "({ ... ; ";
+ Helper->handledStmt(*SE->getSubStmt()->body_rbegin(),OS);
+ OS << " })\n";
+ return;
+ }
+ }
+
+ // special printing for comma expressions.
+ if (BinaryOperator* B = dyn_cast<BinaryOperator>(Terminator)) {
+ if (B->getOpcode() == BinaryOperator::Comma) {
+ OS << "... , ";
+ Helper->handledStmt(B->getRHS(),OS);
+ OS << '\n';
+ return;
+ }
+ }
+ }
+
+ Terminator->printPretty(OS, Helper, PrintingPolicy(Helper->getLangOpts()));
+
+ // Expressions need a newline.
+ if (isa<Expr>(Terminator)) OS << '\n';
+}
+
+static void print_block(llvm::raw_ostream& OS, const CFG* cfg,
+ const CFGBlock& B,
+ StmtPrinterHelper* Helper, bool print_edges) {
+
+ if (Helper) Helper->setBlockID(B.getBlockID());
+
+ // Print the header.
+ OS << "\n [ B" << B.getBlockID();
+
+ if (&B == &cfg->getEntry())
+ OS << " (ENTRY) ]\n";
+ else if (&B == &cfg->getExit())
+ OS << " (EXIT) ]\n";
+ else if (&B == cfg->getIndirectGotoBlock())
+ OS << " (INDIRECT GOTO DISPATCH) ]\n";
+ else
+ OS << " ]\n";
+
+ // Print the label of this block.
+ if (Stmt* Label = const_cast<Stmt*>(B.getLabel())) {
+
+ if (print_edges)
+ OS << " ";
+
+ if (LabelStmt* L = dyn_cast<LabelStmt>(Label))
+ OS << L->getName();
+ else if (CaseStmt* C = dyn_cast<CaseStmt>(Label)) {
+ OS << "case ";
+ C->getLHS()->printPretty(OS, Helper,
+ PrintingPolicy(Helper->getLangOpts()));
+ if (C->getRHS()) {
+ OS << " ... ";
+ C->getRHS()->printPretty(OS, Helper,
+ PrintingPolicy(Helper->getLangOpts()));
+ }
+ } else if (isa<DefaultStmt>(Label))
+ OS << "default";
+ else if (CXXCatchStmt *CS = dyn_cast<CXXCatchStmt>(Label)) {
+ OS << "catch (";
+ if (CS->getExceptionDecl())
+ CS->getExceptionDecl()->print(OS, PrintingPolicy(Helper->getLangOpts()),
+ 0);
+ else
+ OS << "...";
+ OS << ")";
+
+ } else
+ assert(false && "Invalid label statement in CFGBlock.");
+
+ OS << ":\n";
+ }
+
+ // Iterate through the statements in the block and print them.
+ unsigned j = 1;
+
+ for (CFGBlock::const_iterator I = B.begin(), E = B.end() ;
+ I != E ; ++I, ++j ) {
+
+ // Print the statement # in the basic block and the statement itself.
+ if (print_edges)
+ OS << " ";
+
+ OS << llvm::format("%3d", j) << ": ";
+
+ if (Helper)
+ Helper->setStmtID(j);
+
+ print_stmt(OS,Helper,*I);
+ }
+
+ // Print the terminator of this block.
+ if (B.getTerminator()) {
+ if (print_edges)
+ OS << " ";
+
+ OS << " T: ";
+
+ if (Helper) Helper->setBlockID(-1);
+
+ CFGBlockTerminatorPrint TPrinter(OS, Helper,
+ PrintingPolicy(Helper->getLangOpts()));
+ TPrinter.Visit(const_cast<Stmt*>(B.getTerminator()));
+ OS << '\n';
+ }
+
+ if (print_edges) {
+ // Print the predecessors of this block.
+ OS << " Predecessors (" << B.pred_size() << "):";
+ unsigned i = 0;
+
+ for (CFGBlock::const_pred_iterator I = B.pred_begin(), E = B.pred_end();
+ I != E; ++I, ++i) {
+
+ if (i == 8 || (i-8) == 0)
+ OS << "\n ";
+
+ OS << " B" << (*I)->getBlockID();
+ }
+
+ OS << '\n';
+
+ // Print the successors of this block.
+ OS << " Successors (" << B.succ_size() << "):";
+ i = 0;
+
+ for (CFGBlock::const_succ_iterator I = B.succ_begin(), E = B.succ_end();
+ I != E; ++I, ++i) {
+
+ if (i == 8 || (i-8) % 10 == 0)
+ OS << "\n ";
+
+ if (*I)
+ OS << " B" << (*I)->getBlockID();
+ else
+ OS << " NULL";
+ }
+
+ OS << '\n';
+ }
+}
+
+
+/// dump - A simple pretty printer of a CFG that outputs to stderr.
+void CFG::dump(const LangOptions &LO) const { print(llvm::errs(), LO); }
+
+/// print - A simple pretty printer of a CFG that outputs to an ostream.
+void CFG::print(llvm::raw_ostream &OS, const LangOptions &LO) const {
+ StmtPrinterHelper Helper(this, LO);
+
+ // Print the entry block.
+ print_block(OS, this, getEntry(), &Helper, true);
+
+ // Iterate through the CFGBlocks and print them one by one.
+ for (const_iterator I = Blocks.begin(), E = Blocks.end() ; I != E ; ++I) {
+ // Skip the entry block, because we already printed it.
+ if (&(**I) == &getEntry() || &(**I) == &getExit())
+ continue;
+
+ print_block(OS, this, **I, &Helper, true);
+ }
+
+ // Print the exit block.
+ print_block(OS, this, getExit(), &Helper, true);
+ OS.flush();
+}
+
+/// dump - A simply pretty printer of a CFGBlock that outputs to stderr.
+void CFGBlock::dump(const CFG* cfg, const LangOptions &LO) const {
+ print(llvm::errs(), cfg, LO);
+}
+
+/// print - A simple pretty printer of a CFGBlock that outputs to an ostream.
+/// Generally this will only be called from CFG::print.
+void CFGBlock::print(llvm::raw_ostream& OS, const CFG* cfg,
+ const LangOptions &LO) const {
+ StmtPrinterHelper Helper(cfg, LO);
+ print_block(OS, cfg, *this, &Helper, true);
+}
+
+/// printTerminator - A simple pretty printer of the terminator of a CFGBlock.
+void CFGBlock::printTerminator(llvm::raw_ostream &OS,
+ const LangOptions &LO) const {
+ CFGBlockTerminatorPrint TPrinter(OS, NULL, PrintingPolicy(LO));
+ TPrinter.Visit(const_cast<Stmt*>(getTerminator()));
+}
+
+Stmt* CFGBlock::getTerminatorCondition() {
+
+ if (!Terminator)
+ return NULL;
+
+ Expr* E = NULL;
+
+ switch (Terminator->getStmtClass()) {
+ default:
+ break;
+
+ case Stmt::ForStmtClass:
+ E = cast<ForStmt>(Terminator)->getCond();
+ break;
+
+ case Stmt::WhileStmtClass:
+ E = cast<WhileStmt>(Terminator)->getCond();
+ break;
+
+ case Stmt::DoStmtClass:
+ E = cast<DoStmt>(Terminator)->getCond();
+ break;
+
+ case Stmt::IfStmtClass:
+ E = cast<IfStmt>(Terminator)->getCond();
+ break;
+
+ case Stmt::ChooseExprClass:
+ E = cast<ChooseExpr>(Terminator)->getCond();
+ break;
+
+ case Stmt::IndirectGotoStmtClass:
+ E = cast<IndirectGotoStmt>(Terminator)->getTarget();
+ break;
+
+ case Stmt::SwitchStmtClass:
+ E = cast<SwitchStmt>(Terminator)->getCond();
+ break;
+
+ case Stmt::ConditionalOperatorClass:
+ E = cast<ConditionalOperator>(Terminator)->getCond();
+ break;
+
+ case Stmt::BinaryOperatorClass: // '&&' and '||'
+ E = cast<BinaryOperator>(Terminator)->getLHS();
+ break;
+
+ case Stmt::ObjCForCollectionStmtClass:
+ return Terminator;
+ }
+
+ return E ? E->IgnoreParens() : NULL;
+}
+
+bool CFGBlock::hasBinaryBranchTerminator() const {
+
+ if (!Terminator)
+ return false;
+
+ Expr* E = NULL;
+
+ switch (Terminator->getStmtClass()) {
+ default:
+ return false;
+
+ case Stmt::ForStmtClass:
+ case Stmt::WhileStmtClass:
+ case Stmt::DoStmtClass:
+ case Stmt::IfStmtClass:
+ case Stmt::ChooseExprClass:
+ case Stmt::ConditionalOperatorClass:
+ case Stmt::BinaryOperatorClass:
+ return true;
+ }
+
+ return E ? E->IgnoreParens() : NULL;
+}
+
+
+//===----------------------------------------------------------------------===//
+// CFG Graphviz Visualization
+//===----------------------------------------------------------------------===//
+
+
+#ifndef NDEBUG
+static StmtPrinterHelper* GraphHelper;
+#endif
+
+void CFG::viewCFG(const LangOptions &LO) const {
+#ifndef NDEBUG
+ StmtPrinterHelper H(this, LO);
+ GraphHelper = &H;
+ llvm::ViewGraph(this,"CFG");
+ GraphHelper = NULL;
+#endif
+}
+
+namespace llvm {
+template<>
+struct DOTGraphTraits<const CFG*> : public DefaultDOTGraphTraits {
+
+ DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
+
+ static std::string getNodeLabel(const CFGBlock* Node, const CFG* Graph) {
+
+#ifndef NDEBUG
+ std::string OutSStr;
+ llvm::raw_string_ostream Out(OutSStr);
+ print_block(Out,Graph, *Node, GraphHelper, false);
+ std::string& OutStr = Out.str();
+
+ if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
+
+ // Process string output to make it nicer...
+ for (unsigned i = 0; i != OutStr.length(); ++i)
+ if (OutStr[i] == '\n') { // Left justify
+ OutStr[i] = '\\';
+ OutStr.insert(OutStr.begin()+i+1, 'l');
+ }
+
+ return OutStr;
+#else
+ return "";
+#endif
+ }
+};
+} // end namespace llvm