1 //===- ThreadSafetyCommon.cpp ----------------------------------*- C++ --*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Implementation of the interfaces declared in ThreadSafetyCommon.h
12 //===----------------------------------------------------------------------===//
14 #include "clang/Analysis/Analyses/ThreadSafetyCommon.h"
15 #include "clang/AST/Attr.h"
16 #include "clang/AST/DeclCXX.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/ExprCXX.h"
19 #include "clang/AST/StmtCXX.h"
20 #include "clang/Analysis/Analyses/PostOrderCFGView.h"
21 #include "clang/Analysis/Analyses/ThreadSafetyTIL.h"
22 #include "clang/Analysis/Analyses/ThreadSafetyTraverse.h"
23 #include "clang/Analysis/AnalysisContext.h"
24 #include "clang/Analysis/CFG.h"
25 #include "clang/Basic/OperatorKinds.h"
26 #include "clang/Basic/SourceLocation.h"
27 #include "clang/Basic/SourceManager.h"
28 #include "llvm/ADT/DenseMap.h"
29 #include "llvm/ADT/SmallVector.h"
30 #include "llvm/ADT/StringRef.h"
37 namespace threadSafety {
39 // From ThreadSafetyUtil.h
40 std::string getSourceLiteralString(const clang::Expr *CE) {
41 switch (CE->getStmtClass()) {
42 case Stmt::IntegerLiteralClass:
43 return cast<IntegerLiteral>(CE)->getValue().toString(10, true);
44 case Stmt::StringLiteralClass: {
45 std::string ret("\"");
46 ret += cast<StringLiteral>(CE)->getString();
50 case Stmt::CharacterLiteralClass:
51 case Stmt::CXXNullPtrLiteralExprClass:
52 case Stmt::GNUNullExprClass:
53 case Stmt::CXXBoolLiteralExprClass:
54 case Stmt::FloatingLiteralClass:
55 case Stmt::ImaginaryLiteralClass:
56 case Stmt::ObjCStringLiteralClass:
64 // Return true if E is a variable that points to an incomplete Phi node.
65 static bool isIncompletePhi(const SExpr *E) {
66 if (const auto *Ph = dyn_cast<Phi>(E))
67 return Ph->status() == Phi::PH_Incomplete;
71 } // end namespace til
74 typedef SExprBuilder::CallingContext CallingContext;
77 til::SExpr *SExprBuilder::lookupStmt(const Stmt *S) {
78 auto It = SMap.find(S);
85 til::SCFG *SExprBuilder::buildCFG(CFGWalker &Walker) {
92 inline bool isCalleeArrow(const Expr *E) {
93 const MemberExpr *ME = dyn_cast<MemberExpr>(E->IgnoreParenCasts());
94 return ME ? ME->isArrow() : false;
98 /// \brief Translate a clang expression in an attribute to a til::SExpr.
99 /// Constructs the context from D, DeclExp, and SelfDecl.
101 /// \param AttrExp The expression to translate.
102 /// \param D The declaration to which the attribute is attached.
103 /// \param DeclExp An expression involving the Decl to which the attribute
104 /// is attached. E.g. the call to a function.
105 CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
109 // If we are processing a raw attribute expression, with no substitutions.
111 return translateAttrExpr(AttrExp, nullptr);
113 CallingContext Ctx(nullptr, D);
115 // Examine DeclExp to find SelfArg and FunArgs, which are used to substitute
116 // for formal parameters when we call buildMutexID later.
117 if (const MemberExpr *ME = dyn_cast<MemberExpr>(DeclExp)) {
118 Ctx.SelfArg = ME->getBase();
119 Ctx.SelfArrow = ME->isArrow();
120 } else if (const CXXMemberCallExpr *CE =
121 dyn_cast<CXXMemberCallExpr>(DeclExp)) {
122 Ctx.SelfArg = CE->getImplicitObjectArgument();
123 Ctx.SelfArrow = isCalleeArrow(CE->getCallee());
124 Ctx.NumArgs = CE->getNumArgs();
125 Ctx.FunArgs = CE->getArgs();
126 } else if (const CallExpr *CE = dyn_cast<CallExpr>(DeclExp)) {
127 Ctx.NumArgs = CE->getNumArgs();
128 Ctx.FunArgs = CE->getArgs();
129 } else if (const CXXConstructExpr *CE =
130 dyn_cast<CXXConstructExpr>(DeclExp)) {
131 Ctx.SelfArg = nullptr; // Will be set below
132 Ctx.NumArgs = CE->getNumArgs();
133 Ctx.FunArgs = CE->getArgs();
134 } else if (D && isa<CXXDestructorDecl>(D)) {
135 // There's no such thing as a "destructor call" in the AST.
136 Ctx.SelfArg = DeclExp;
139 // Hack to handle constructors, where self cannot be recovered from
141 if (SelfDecl && !Ctx.SelfArg) {
142 DeclRefExpr SelfDRE(SelfDecl, false, SelfDecl->getType(), VK_LValue,
143 SelfDecl->getLocation());
144 Ctx.SelfArg = &SelfDRE;
146 // If the attribute has no arguments, then assume the argument is "this".
148 return translateAttrExpr(Ctx.SelfArg, nullptr);
149 else // For most attributes.
150 return translateAttrExpr(AttrExp, &Ctx);
153 // If the attribute has no arguments, then assume the argument is "this".
155 return translateAttrExpr(Ctx.SelfArg, nullptr);
156 else // For most attributes.
157 return translateAttrExpr(AttrExp, &Ctx);
161 /// \brief Translate a clang expression in an attribute to a til::SExpr.
162 // This assumes a CallingContext has already been created.
163 CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
164 CallingContext *Ctx) {
166 return CapabilityExpr(nullptr, false);
168 if (auto* SLit = dyn_cast<StringLiteral>(AttrExp)) {
169 if (SLit->getString() == StringRef("*"))
170 // The "*" expr is a universal lock, which essentially turns off
171 // checks until it is removed from the lockset.
172 return CapabilityExpr(new (Arena) til::Wildcard(), false);
174 // Ignore other string literals for now.
175 return CapabilityExpr(nullptr, false);
179 if (auto *OE = dyn_cast<CXXOperatorCallExpr>(AttrExp)) {
180 if (OE->getOperator() == OO_Exclaim) {
182 AttrExp = OE->getArg(0);
185 else if (auto *UO = dyn_cast<UnaryOperator>(AttrExp)) {
186 if (UO->getOpcode() == UO_LNot) {
188 AttrExp = UO->getSubExpr();
192 til::SExpr *E = translate(AttrExp, Ctx);
194 // Trap mutex expressions like nullptr, or 0.
195 // Any literal value is nonsense.
196 if (!E || isa<til::Literal>(E))
197 return CapabilityExpr(nullptr, false);
199 // Hack to deal with smart pointers -- strip off top-level pointer casts.
200 if (auto *CE = dyn_cast_or_null<til::Cast>(E)) {
201 if (CE->castOpcode() == til::CAST_objToPtr)
202 return CapabilityExpr(CE->expr(), Neg);
204 return CapabilityExpr(E, Neg);
209 // Translate a clang statement or expression to a TIL expression.
210 // Also performs substitution of variables; Ctx provides the context.
211 // Dispatches on the type of S.
212 til::SExpr *SExprBuilder::translate(const Stmt *S, CallingContext *Ctx) {
216 // Check if S has already been translated and cached.
217 // This handles the lookup of SSA names for DeclRefExprs here.
218 if (til::SExpr *E = lookupStmt(S))
221 switch (S->getStmtClass()) {
222 case Stmt::DeclRefExprClass:
223 return translateDeclRefExpr(cast<DeclRefExpr>(S), Ctx);
224 case Stmt::CXXThisExprClass:
225 return translateCXXThisExpr(cast<CXXThisExpr>(S), Ctx);
226 case Stmt::MemberExprClass:
227 return translateMemberExpr(cast<MemberExpr>(S), Ctx);
228 case Stmt::CallExprClass:
229 return translateCallExpr(cast<CallExpr>(S), Ctx);
230 case Stmt::CXXMemberCallExprClass:
231 return translateCXXMemberCallExpr(cast<CXXMemberCallExpr>(S), Ctx);
232 case Stmt::CXXOperatorCallExprClass:
233 return translateCXXOperatorCallExpr(cast<CXXOperatorCallExpr>(S), Ctx);
234 case Stmt::UnaryOperatorClass:
235 return translateUnaryOperator(cast<UnaryOperator>(S), Ctx);
236 case Stmt::BinaryOperatorClass:
237 case Stmt::CompoundAssignOperatorClass:
238 return translateBinaryOperator(cast<BinaryOperator>(S), Ctx);
240 case Stmt::ArraySubscriptExprClass:
241 return translateArraySubscriptExpr(cast<ArraySubscriptExpr>(S), Ctx);
242 case Stmt::ConditionalOperatorClass:
243 return translateAbstractConditionalOperator(
244 cast<ConditionalOperator>(S), Ctx);
245 case Stmt::BinaryConditionalOperatorClass:
246 return translateAbstractConditionalOperator(
247 cast<BinaryConditionalOperator>(S), Ctx);
249 // We treat these as no-ops
250 case Stmt::ParenExprClass:
251 return translate(cast<ParenExpr>(S)->getSubExpr(), Ctx);
252 case Stmt::ExprWithCleanupsClass:
253 return translate(cast<ExprWithCleanups>(S)->getSubExpr(), Ctx);
254 case Stmt::CXXBindTemporaryExprClass:
255 return translate(cast<CXXBindTemporaryExpr>(S)->getSubExpr(), Ctx);
257 // Collect all literals
258 case Stmt::CharacterLiteralClass:
259 case Stmt::CXXNullPtrLiteralExprClass:
260 case Stmt::GNUNullExprClass:
261 case Stmt::CXXBoolLiteralExprClass:
262 case Stmt::FloatingLiteralClass:
263 case Stmt::ImaginaryLiteralClass:
264 case Stmt::IntegerLiteralClass:
265 case Stmt::StringLiteralClass:
266 case Stmt::ObjCStringLiteralClass:
267 return new (Arena) til::Literal(cast<Expr>(S));
269 case Stmt::DeclStmtClass:
270 return translateDeclStmt(cast<DeclStmt>(S), Ctx);
274 if (const CastExpr *CE = dyn_cast<CastExpr>(S))
275 return translateCastExpr(CE, Ctx);
277 return new (Arena) til::Undefined(S);
282 til::SExpr *SExprBuilder::translateDeclRefExpr(const DeclRefExpr *DRE,
283 CallingContext *Ctx) {
284 const ValueDecl *VD = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
286 // Function parameters require substitution and/or renaming.
287 if (const ParmVarDecl *PV = dyn_cast_or_null<ParmVarDecl>(VD)) {
288 const FunctionDecl *FD =
289 cast<FunctionDecl>(PV->getDeclContext())->getCanonicalDecl();
290 unsigned I = PV->getFunctionScopeIndex();
292 if (Ctx && Ctx->FunArgs && FD == Ctx->AttrDecl->getCanonicalDecl()) {
293 // Substitute call arguments for references to function parameters
294 assert(I < Ctx->NumArgs);
295 return translate(Ctx->FunArgs[I], Ctx->Prev);
297 // Map the param back to the param of the original function declaration
298 // for consistent comparisons.
299 VD = FD->getParamDecl(I);
302 // For non-local variables, treat it as a referenced to a named object.
303 return new (Arena) til::LiteralPtr(VD);
307 til::SExpr *SExprBuilder::translateCXXThisExpr(const CXXThisExpr *TE,
308 CallingContext *Ctx) {
309 // Substitute for 'this'
310 if (Ctx && Ctx->SelfArg)
311 return translate(Ctx->SelfArg, Ctx->Prev);
312 assert(SelfVar && "We have no variable for 'this'!");
317 const ValueDecl *getValueDeclFromSExpr(const til::SExpr *E) {
318 if (auto *V = dyn_cast<til::Variable>(E))
319 return V->clangDecl();
320 if (auto *Ph = dyn_cast<til::Phi>(E))
321 return Ph->clangDecl();
322 if (auto *P = dyn_cast<til::Project>(E))
323 return P->clangDecl();
324 if (auto *L = dyn_cast<til::LiteralPtr>(E))
325 return L->clangDecl();
329 bool hasCppPointerType(const til::SExpr *E) {
330 auto *VD = getValueDeclFromSExpr(E);
331 if (VD && VD->getType()->isPointerType())
333 if (auto *C = dyn_cast<til::Cast>(E))
334 return C->castOpcode() == til::CAST_objToPtr;
340 // Grab the very first declaration of virtual method D
341 const CXXMethodDecl* getFirstVirtualDecl(const CXXMethodDecl *D) {
343 D = D->getCanonicalDecl();
344 CXXMethodDecl::method_iterator I = D->begin_overridden_methods(),
345 E = D->end_overridden_methods();
347 return D; // Method does not override anything
348 D = *I; // FIXME: this does not work with multiple inheritance.
353 til::SExpr *SExprBuilder::translateMemberExpr(const MemberExpr *ME,
354 CallingContext *Ctx) {
355 til::SExpr *BE = translate(ME->getBase(), Ctx);
356 til::SExpr *E = new (Arena) til::SApply(BE);
358 const ValueDecl *D = ME->getMemberDecl();
359 if (auto *VD = dyn_cast<CXXMethodDecl>(D))
360 D = getFirstVirtualDecl(VD);
362 til::Project *P = new (Arena) til::Project(E, D);
363 if (hasCppPointerType(BE))
369 til::SExpr *SExprBuilder::translateCallExpr(const CallExpr *CE,
372 if (CapabilityExprMode) {
373 // Handle LOCK_RETURNED
374 const FunctionDecl *FD = CE->getDirectCallee()->getMostRecentDecl();
375 if (LockReturnedAttr* At = FD->getAttr<LockReturnedAttr>()) {
376 CallingContext LRCallCtx(Ctx);
377 LRCallCtx.AttrDecl = CE->getDirectCallee();
378 LRCallCtx.SelfArg = SelfE;
379 LRCallCtx.NumArgs = CE->getNumArgs();
380 LRCallCtx.FunArgs = CE->getArgs();
381 return const_cast<til::SExpr*>(
382 translateAttrExpr(At->getArg(), &LRCallCtx).sexpr());
386 til::SExpr *E = translate(CE->getCallee(), Ctx);
387 for (const auto *Arg : CE->arguments()) {
388 til::SExpr *A = translate(Arg, Ctx);
389 E = new (Arena) til::Apply(E, A);
391 return new (Arena) til::Call(E, CE);
395 til::SExpr *SExprBuilder::translateCXXMemberCallExpr(
396 const CXXMemberCallExpr *ME, CallingContext *Ctx) {
397 if (CapabilityExprMode) {
398 // Ignore calls to get() on smart pointers.
399 if (ME->getMethodDecl()->getNameAsString() == "get" &&
400 ME->getNumArgs() == 0) {
401 auto *E = translate(ME->getImplicitObjectArgument(), Ctx);
402 return new (Arena) til::Cast(til::CAST_objToPtr, E);
406 return translateCallExpr(cast<CallExpr>(ME), Ctx,
407 ME->getImplicitObjectArgument());
411 til::SExpr *SExprBuilder::translateCXXOperatorCallExpr(
412 const CXXOperatorCallExpr *OCE, CallingContext *Ctx) {
413 if (CapabilityExprMode) {
414 // Ignore operator * and operator -> on smart pointers.
415 OverloadedOperatorKind k = OCE->getOperator();
416 if (k == OO_Star || k == OO_Arrow) {
417 auto *E = translate(OCE->getArg(0), Ctx);
418 return new (Arena) til::Cast(til::CAST_objToPtr, E);
422 return translateCallExpr(cast<CallExpr>(OCE), Ctx);
426 til::SExpr *SExprBuilder::translateUnaryOperator(const UnaryOperator *UO,
427 CallingContext *Ctx) {
428 switch (UO->getOpcode()) {
433 return new (Arena) til::Undefined(UO);
436 if (CapabilityExprMode) {
437 // interpret &Graph::mu_ as an existential.
438 if (DeclRefExpr* DRE = dyn_cast<DeclRefExpr>(UO->getSubExpr())) {
439 if (DRE->getDecl()->isCXXInstanceMember()) {
440 // This is a pointer-to-member expression, e.g. &MyClass::mu_.
441 // We interpret this syntax specially, as a wildcard.
442 auto *W = new (Arena) til::Wildcard();
443 return new (Arena) til::Project(W, DRE->getDecl());
447 // otherwise, & is a no-op
448 return translate(UO->getSubExpr(), Ctx);
451 // We treat these as no-ops
454 return translate(UO->getSubExpr(), Ctx);
458 til::UnaryOp(til::UOP_Minus, translate(UO->getSubExpr(), Ctx));
461 til::UnaryOp(til::UOP_BitNot, translate(UO->getSubExpr(), Ctx));
464 til::UnaryOp(til::UOP_LogicNot, translate(UO->getSubExpr(), Ctx));
466 // Currently unsupported
470 return new (Arena) til::Undefined(UO);
472 return new (Arena) til::Undefined(UO);
476 til::SExpr *SExprBuilder::translateBinOp(til::TIL_BinaryOpcode Op,
477 const BinaryOperator *BO,
478 CallingContext *Ctx, bool Reverse) {
479 til::SExpr *E0 = translate(BO->getLHS(), Ctx);
480 til::SExpr *E1 = translate(BO->getRHS(), Ctx);
482 return new (Arena) til::BinaryOp(Op, E1, E0);
484 return new (Arena) til::BinaryOp(Op, E0, E1);
488 til::SExpr *SExprBuilder::translateBinAssign(til::TIL_BinaryOpcode Op,
489 const BinaryOperator *BO,
492 const Expr *LHS = BO->getLHS();
493 const Expr *RHS = BO->getRHS();
494 til::SExpr *E0 = translate(LHS, Ctx);
495 til::SExpr *E1 = translate(RHS, Ctx);
497 const ValueDecl *VD = nullptr;
498 til::SExpr *CV = nullptr;
499 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(LHS)) {
501 CV = lookupVarDecl(VD);
505 til::SExpr *Arg = CV ? CV : new (Arena) til::Load(E0);
506 E1 = new (Arena) til::BinaryOp(Op, Arg, E1);
507 E1 = addStatement(E1, nullptr, VD);
510 return updateVarDecl(VD, E1);
511 return new (Arena) til::Store(E0, E1);
515 til::SExpr *SExprBuilder::translateBinaryOperator(const BinaryOperator *BO,
516 CallingContext *Ctx) {
517 switch (BO->getOpcode()) {
520 return new (Arena) til::Undefined(BO);
522 case BO_Mul: return translateBinOp(til::BOP_Mul, BO, Ctx);
523 case BO_Div: return translateBinOp(til::BOP_Div, BO, Ctx);
524 case BO_Rem: return translateBinOp(til::BOP_Rem, BO, Ctx);
525 case BO_Add: return translateBinOp(til::BOP_Add, BO, Ctx);
526 case BO_Sub: return translateBinOp(til::BOP_Sub, BO, Ctx);
527 case BO_Shl: return translateBinOp(til::BOP_Shl, BO, Ctx);
528 case BO_Shr: return translateBinOp(til::BOP_Shr, BO, Ctx);
529 case BO_LT: return translateBinOp(til::BOP_Lt, BO, Ctx);
530 case BO_GT: return translateBinOp(til::BOP_Lt, BO, Ctx, true);
531 case BO_LE: return translateBinOp(til::BOP_Leq, BO, Ctx);
532 case BO_GE: return translateBinOp(til::BOP_Leq, BO, Ctx, true);
533 case BO_EQ: return translateBinOp(til::BOP_Eq, BO, Ctx);
534 case BO_NE: return translateBinOp(til::BOP_Neq, BO, Ctx);
535 case BO_And: return translateBinOp(til::BOP_BitAnd, BO, Ctx);
536 case BO_Xor: return translateBinOp(til::BOP_BitXor, BO, Ctx);
537 case BO_Or: return translateBinOp(til::BOP_BitOr, BO, Ctx);
538 case BO_LAnd: return translateBinOp(til::BOP_LogicAnd, BO, Ctx);
539 case BO_LOr: return translateBinOp(til::BOP_LogicOr, BO, Ctx);
541 case BO_Assign: return translateBinAssign(til::BOP_Eq, BO, Ctx, true);
542 case BO_MulAssign: return translateBinAssign(til::BOP_Mul, BO, Ctx);
543 case BO_DivAssign: return translateBinAssign(til::BOP_Div, BO, Ctx);
544 case BO_RemAssign: return translateBinAssign(til::BOP_Rem, BO, Ctx);
545 case BO_AddAssign: return translateBinAssign(til::BOP_Add, BO, Ctx);
546 case BO_SubAssign: return translateBinAssign(til::BOP_Sub, BO, Ctx);
547 case BO_ShlAssign: return translateBinAssign(til::BOP_Shl, BO, Ctx);
548 case BO_ShrAssign: return translateBinAssign(til::BOP_Shr, BO, Ctx);
549 case BO_AndAssign: return translateBinAssign(til::BOP_BitAnd, BO, Ctx);
550 case BO_XorAssign: return translateBinAssign(til::BOP_BitXor, BO, Ctx);
551 case BO_OrAssign: return translateBinAssign(til::BOP_BitOr, BO, Ctx);
554 // The clang CFG should have already processed both sides.
555 return translate(BO->getRHS(), Ctx);
557 return new (Arena) til::Undefined(BO);
561 til::SExpr *SExprBuilder::translateCastExpr(const CastExpr *CE,
562 CallingContext *Ctx) {
563 clang::CastKind K = CE->getCastKind();
565 case CK_LValueToRValue: {
566 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
567 til::SExpr *E0 = lookupVarDecl(DRE->getDecl());
571 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
573 // FIXME!! -- get Load working properly
574 // return new (Arena) til::Load(E0);
577 case CK_DerivedToBase:
578 case CK_UncheckedDerivedToBase:
579 case CK_ArrayToPointerDecay:
580 case CK_FunctionToPointerDecay: {
581 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
585 // FIXME: handle different kinds of casts.
586 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
587 if (CapabilityExprMode)
589 return new (Arena) til::Cast(til::CAST_none, E0);
596 SExprBuilder::translateArraySubscriptExpr(const ArraySubscriptExpr *E,
597 CallingContext *Ctx) {
598 til::SExpr *E0 = translate(E->getBase(), Ctx);
599 til::SExpr *E1 = translate(E->getIdx(), Ctx);
600 return new (Arena) til::ArrayIndex(E0, E1);
605 SExprBuilder::translateAbstractConditionalOperator(
606 const AbstractConditionalOperator *CO, CallingContext *Ctx) {
607 auto *C = translate(CO->getCond(), Ctx);
608 auto *T = translate(CO->getTrueExpr(), Ctx);
609 auto *E = translate(CO->getFalseExpr(), Ctx);
610 return new (Arena) til::IfThenElse(C, T, E);
615 SExprBuilder::translateDeclStmt(const DeclStmt *S, CallingContext *Ctx) {
616 DeclGroupRef DGrp = S->getDeclGroup();
617 for (DeclGroupRef::iterator I = DGrp.begin(), E = DGrp.end(); I != E; ++I) {
618 if (VarDecl *VD = dyn_cast_or_null<VarDecl>(*I)) {
619 Expr *E = VD->getInit();
620 til::SExpr* SE = translate(E, Ctx);
622 // Add local variables with trivial type to the variable map
623 QualType T = VD->getType();
624 if (T.isTrivialType(VD->getASTContext())) {
625 return addVarDecl(VD, SE);
637 // If (E) is non-trivial, then add it to the current basic block, and
638 // update the statement map so that S refers to E. Returns a new variable
640 // If E is trivial returns E.
641 til::SExpr *SExprBuilder::addStatement(til::SExpr* E, const Stmt *S,
642 const ValueDecl *VD) {
643 if (!E || !CurrentBB || E->block() || til::ThreadSafetyTIL::isTrivial(E))
646 E = new (Arena) til::Variable(E, VD);
647 CurrentInstructions.push_back(E);
654 // Returns the current value of VD, if known, and nullptr otherwise.
655 til::SExpr *SExprBuilder::lookupVarDecl(const ValueDecl *VD) {
656 auto It = LVarIdxMap.find(VD);
657 if (It != LVarIdxMap.end()) {
658 assert(CurrentLVarMap[It->second].first == VD);
659 return CurrentLVarMap[It->second].second;
665 // if E is a til::Variable, update its clangDecl.
666 inline void maybeUpdateVD(til::SExpr *E, const ValueDecl *VD) {
669 if (til::Variable *V = dyn_cast<til::Variable>(E)) {
675 // Adds a new variable declaration.
676 til::SExpr *SExprBuilder::addVarDecl(const ValueDecl *VD, til::SExpr *E) {
677 maybeUpdateVD(E, VD);
678 LVarIdxMap.insert(std::make_pair(VD, CurrentLVarMap.size()));
679 CurrentLVarMap.makeWritable();
680 CurrentLVarMap.push_back(std::make_pair(VD, E));
685 // Updates a current variable declaration. (E.g. by assignment)
686 til::SExpr *SExprBuilder::updateVarDecl(const ValueDecl *VD, til::SExpr *E) {
687 maybeUpdateVD(E, VD);
688 auto It = LVarIdxMap.find(VD);
689 if (It == LVarIdxMap.end()) {
690 til::SExpr *Ptr = new (Arena) til::LiteralPtr(VD);
691 til::SExpr *St = new (Arena) til::Store(Ptr, E);
694 CurrentLVarMap.makeWritable();
695 CurrentLVarMap.elem(It->second).second = E;
700 // Make a Phi node in the current block for the i^th variable in CurrentVarMap.
701 // If E != null, sets Phi[CurrentBlockInfo->ArgIndex] = E.
702 // If E == null, this is a backedge and will be set later.
703 void SExprBuilder::makePhiNodeVar(unsigned i, unsigned NPreds, til::SExpr *E) {
704 unsigned ArgIndex = CurrentBlockInfo->ProcessedPredecessors;
705 assert(ArgIndex > 0 && ArgIndex < NPreds);
707 til::SExpr *CurrE = CurrentLVarMap[i].second;
708 if (CurrE->block() == CurrentBB) {
709 // We already have a Phi node in the current block,
710 // so just add the new variable to the Phi node.
711 til::Phi *Ph = dyn_cast<til::Phi>(CurrE);
712 assert(Ph && "Expecting Phi node.");
714 Ph->values()[ArgIndex] = E;
718 // Make a new phi node: phi(..., E)
719 // All phi args up to the current index are set to the current value.
720 til::Phi *Ph = new (Arena) til::Phi(Arena, NPreds);
721 Ph->values().setValues(NPreds, nullptr);
722 for (unsigned PIdx = 0; PIdx < ArgIndex; ++PIdx)
723 Ph->values()[PIdx] = CurrE;
725 Ph->values()[ArgIndex] = E;
726 Ph->setClangDecl(CurrentLVarMap[i].first);
727 // If E is from a back-edge, or either E or CurrE are incomplete, then
728 // mark this node as incomplete; we may need to remove it later.
729 if (!E || isIncompletePhi(E) || isIncompletePhi(CurrE)) {
730 Ph->setStatus(til::Phi::PH_Incomplete);
733 // Add Phi node to current block, and update CurrentLVarMap[i]
734 CurrentArguments.push_back(Ph);
735 if (Ph->status() == til::Phi::PH_Incomplete)
736 IncompleteArgs.push_back(Ph);
738 CurrentLVarMap.makeWritable();
739 CurrentLVarMap.elem(i).second = Ph;
743 // Merge values from Map into the current variable map.
744 // This will construct Phi nodes in the current basic block as necessary.
745 void SExprBuilder::mergeEntryMap(LVarDefinitionMap Map) {
746 assert(CurrentBlockInfo && "Not processing a block!");
748 if (!CurrentLVarMap.valid()) {
749 // Steal Map, using copy-on-write.
750 CurrentLVarMap = std::move(Map);
753 if (CurrentLVarMap.sameAs(Map))
754 return; // Easy merge: maps from different predecessors are unchanged.
756 unsigned NPreds = CurrentBB->numPredecessors();
757 unsigned ESz = CurrentLVarMap.size();
758 unsigned MSz = Map.size();
759 unsigned Sz = std::min(ESz, MSz);
761 for (unsigned i=0; i<Sz; ++i) {
762 if (CurrentLVarMap[i].first != Map[i].first) {
763 // We've reached the end of variables in common.
764 CurrentLVarMap.makeWritable();
765 CurrentLVarMap.downsize(i);
768 if (CurrentLVarMap[i].second != Map[i].second)
769 makePhiNodeVar(i, NPreds, Map[i].second);
772 CurrentLVarMap.makeWritable();
773 CurrentLVarMap.downsize(Map.size());
778 // Merge a back edge into the current variable map.
779 // This will create phi nodes for all variables in the variable map.
780 void SExprBuilder::mergeEntryMapBackEdge() {
781 // We don't have definitions for variables on the backedge, because we
782 // haven't gotten that far in the CFG. Thus, when encountering a back edge,
783 // we conservatively create Phi nodes for all variables. Unnecessary Phi
784 // nodes will be marked as incomplete, and stripped out at the end.
786 // An Phi node is unnecessary if it only refers to itself and one other
787 // variable, e.g. x = Phi(y, y, x) can be reduced to x = y.
789 assert(CurrentBlockInfo && "Not processing a block!");
791 if (CurrentBlockInfo->HasBackEdges)
793 CurrentBlockInfo->HasBackEdges = true;
795 CurrentLVarMap.makeWritable();
796 unsigned Sz = CurrentLVarMap.size();
797 unsigned NPreds = CurrentBB->numPredecessors();
799 for (unsigned i=0; i < Sz; ++i) {
800 makePhiNodeVar(i, NPreds, nullptr);
805 // Update the phi nodes that were initially created for a back edge
806 // once the variable definitions have been computed.
807 // I.e., merge the current variable map into the phi nodes for Blk.
808 void SExprBuilder::mergePhiNodesBackEdge(const CFGBlock *Blk) {
809 til::BasicBlock *BB = lookupBlock(Blk);
810 unsigned ArgIndex = BBInfo[Blk->getBlockID()].ProcessedPredecessors;
811 assert(ArgIndex > 0 && ArgIndex < BB->numPredecessors());
813 for (til::SExpr *PE : BB->arguments()) {
814 til::Phi *Ph = dyn_cast_or_null<til::Phi>(PE);
815 assert(Ph && "Expecting Phi Node.");
816 assert(Ph->values()[ArgIndex] == nullptr && "Wrong index for back edge.");
818 til::SExpr *E = lookupVarDecl(Ph->clangDecl());
819 assert(E && "Couldn't find local variable for Phi node.");
820 Ph->values()[ArgIndex] = E;
824 void SExprBuilder::enterCFG(CFG *Cfg, const NamedDecl *D,
825 const CFGBlock *First) {
826 // Perform initial setup operations.
827 unsigned NBlocks = Cfg->getNumBlockIDs();
828 Scfg = new (Arena) til::SCFG(Arena, NBlocks);
830 // allocate all basic blocks immediately, to handle forward references.
831 BBInfo.resize(NBlocks);
832 BlockMap.resize(NBlocks, nullptr);
833 // create map from clang blockID to til::BasicBlocks
834 for (auto *B : *Cfg) {
835 auto *BB = new (Arena) til::BasicBlock(Arena);
836 BB->reserveInstructions(B->size());
837 BlockMap[B->getBlockID()] = BB;
840 CurrentBB = lookupBlock(&Cfg->getEntry());
841 auto Parms = isa<ObjCMethodDecl>(D) ? cast<ObjCMethodDecl>(D)->parameters()
842 : cast<FunctionDecl>(D)->parameters();
843 for (auto *Pm : Parms) {
844 QualType T = Pm->getType();
845 if (!T.isTrivialType(Pm->getASTContext()))
848 // Add parameters to local variable map.
849 // FIXME: right now we emulate params with loads; that should be fixed.
850 til::SExpr *Lp = new (Arena) til::LiteralPtr(Pm);
851 til::SExpr *Ld = new (Arena) til::Load(Lp);
852 til::SExpr *V = addStatement(Ld, nullptr, Pm);
858 void SExprBuilder::enterCFGBlock(const CFGBlock *B) {
859 // Intialize TIL basic block and add it to the CFG.
860 CurrentBB = lookupBlock(B);
861 CurrentBB->reservePredecessors(B->pred_size());
862 Scfg->add(CurrentBB);
864 CurrentBlockInfo = &BBInfo[B->getBlockID()];
866 // CurrentLVarMap is moved to ExitMap on block exit.
867 // FIXME: the entry block will hold function parameters.
868 // assert(!CurrentLVarMap.valid() && "CurrentLVarMap already initialized.");
872 void SExprBuilder::handlePredecessor(const CFGBlock *Pred) {
873 // Compute CurrentLVarMap on entry from ExitMaps of predecessors
875 CurrentBB->addPredecessor(BlockMap[Pred->getBlockID()]);
876 BlockInfo *PredInfo = &BBInfo[Pred->getBlockID()];
877 assert(PredInfo->UnprocessedSuccessors > 0);
879 if (--PredInfo->UnprocessedSuccessors == 0)
880 mergeEntryMap(std::move(PredInfo->ExitMap));
882 mergeEntryMap(PredInfo->ExitMap.clone());
884 ++CurrentBlockInfo->ProcessedPredecessors;
888 void SExprBuilder::handlePredecessorBackEdge(const CFGBlock *Pred) {
889 mergeEntryMapBackEdge();
893 void SExprBuilder::enterCFGBlockBody(const CFGBlock *B) {
894 // The merge*() methods have created arguments.
895 // Push those arguments onto the basic block.
896 CurrentBB->arguments().reserve(
897 static_cast<unsigned>(CurrentArguments.size()), Arena);
898 for (auto *A : CurrentArguments)
899 CurrentBB->addArgument(A);
903 void SExprBuilder::handleStatement(const Stmt *S) {
904 til::SExpr *E = translate(S, nullptr);
909 void SExprBuilder::handleDestructorCall(const VarDecl *VD,
910 const CXXDestructorDecl *DD) {
911 til::SExpr *Sf = new (Arena) til::LiteralPtr(VD);
912 til::SExpr *Dr = new (Arena) til::LiteralPtr(DD);
913 til::SExpr *Ap = new (Arena) til::Apply(Dr, Sf);
914 til::SExpr *E = new (Arena) til::Call(Ap);
915 addStatement(E, nullptr);
920 void SExprBuilder::exitCFGBlockBody(const CFGBlock *B) {
921 CurrentBB->instructions().reserve(
922 static_cast<unsigned>(CurrentInstructions.size()), Arena);
923 for (auto *V : CurrentInstructions)
924 CurrentBB->addInstruction(V);
926 // Create an appropriate terminator
927 unsigned N = B->succ_size();
928 auto It = B->succ_begin();
930 til::BasicBlock *BB = *It ? lookupBlock(*It) : nullptr;
932 unsigned Idx = BB ? BB->findPredecessorIndex(CurrentBB) : 0;
933 auto *Tm = new (Arena) til::Goto(BB, Idx);
934 CurrentBB->setTerminator(Tm);
937 til::SExpr *C = translate(B->getTerminatorCondition(true), nullptr);
938 til::BasicBlock *BB1 = *It ? lookupBlock(*It) : nullptr;
940 til::BasicBlock *BB2 = *It ? lookupBlock(*It) : nullptr;
941 // FIXME: make sure these arent' critical edges.
942 auto *Tm = new (Arena) til::Branch(C, BB1, BB2);
943 CurrentBB->setTerminator(Tm);
948 void SExprBuilder::handleSuccessor(const CFGBlock *Succ) {
949 ++CurrentBlockInfo->UnprocessedSuccessors;
953 void SExprBuilder::handleSuccessorBackEdge(const CFGBlock *Succ) {
954 mergePhiNodesBackEdge(Succ);
955 ++BBInfo[Succ->getBlockID()].ProcessedPredecessors;
959 void SExprBuilder::exitCFGBlock(const CFGBlock *B) {
960 CurrentArguments.clear();
961 CurrentInstructions.clear();
962 CurrentBlockInfo->ExitMap = std::move(CurrentLVarMap);
964 CurrentBlockInfo = nullptr;
968 void SExprBuilder::exitCFG(const CFGBlock *Last) {
969 for (auto *Ph : IncompleteArgs) {
970 if (Ph->status() == til::Phi::PH_Incomplete)
971 simplifyIncompleteArg(Ph);
974 CurrentArguments.clear();
975 CurrentInstructions.clear();
976 IncompleteArgs.clear();
981 void printSCFG(CFGWalker &Walker) {
982 llvm::BumpPtrAllocator Bpa;
983 til::MemRegionRef Arena(&Bpa);
984 SExprBuilder SxBuilder(Arena);
985 til::SCFG *Scfg = SxBuilder.buildCFG(Walker);
986 TILPrinter::print(Scfg, llvm::errs());
991 } // end namespace threadSafety
993 } // end namespace clang