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"
35 using namespace clang;
36 using namespace threadSafety;
38 // From ThreadSafetyUtil.h
39 std::string threadSafety::getSourceLiteralString(const clang::Expr *CE) {
40 switch (CE->getStmtClass()) {
41 case Stmt::IntegerLiteralClass:
42 return cast<IntegerLiteral>(CE)->getValue().toString(10, true);
43 case Stmt::StringLiteralClass: {
44 std::string ret("\"");
45 ret += cast<StringLiteral>(CE)->getString();
49 case Stmt::CharacterLiteralClass:
50 case Stmt::CXXNullPtrLiteralExprClass:
51 case Stmt::GNUNullExprClass:
52 case Stmt::CXXBoolLiteralExprClass:
53 case Stmt::FloatingLiteralClass:
54 case Stmt::ImaginaryLiteralClass:
55 case Stmt::ObjCStringLiteralClass:
61 // Return true if E is a variable that points to an incomplete Phi node.
62 static bool isIncompletePhi(const til::SExpr *E) {
63 if (const auto *Ph = dyn_cast<til::Phi>(E))
64 return Ph->status() == til::Phi::PH_Incomplete;
68 typedef SExprBuilder::CallingContext CallingContext;
70 til::SExpr *SExprBuilder::lookupStmt(const Stmt *S) {
71 auto It = SMap.find(S);
77 til::SCFG *SExprBuilder::buildCFG(CFGWalker &Walker) {
82 static bool isCalleeArrow(const Expr *E) {
83 const MemberExpr *ME = dyn_cast<MemberExpr>(E->IgnoreParenCasts());
84 return ME ? ME->isArrow() : false;
87 /// \brief Translate a clang expression in an attribute to a til::SExpr.
88 /// Constructs the context from D, DeclExp, and SelfDecl.
90 /// \param AttrExp The expression to translate.
91 /// \param D The declaration to which the attribute is attached.
92 /// \param DeclExp An expression involving the Decl to which the attribute
93 /// is attached. E.g. the call to a function.
94 CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
98 // If we are processing a raw attribute expression, with no substitutions.
100 return translateAttrExpr(AttrExp, nullptr);
102 CallingContext Ctx(nullptr, D);
104 // Examine DeclExp to find SelfArg and FunArgs, which are used to substitute
105 // for formal parameters when we call buildMutexID later.
106 if (const MemberExpr *ME = dyn_cast<MemberExpr>(DeclExp)) {
107 Ctx.SelfArg = ME->getBase();
108 Ctx.SelfArrow = ME->isArrow();
109 } else if (const CXXMemberCallExpr *CE =
110 dyn_cast<CXXMemberCallExpr>(DeclExp)) {
111 Ctx.SelfArg = CE->getImplicitObjectArgument();
112 Ctx.SelfArrow = isCalleeArrow(CE->getCallee());
113 Ctx.NumArgs = CE->getNumArgs();
114 Ctx.FunArgs = CE->getArgs();
115 } else if (const CallExpr *CE = dyn_cast<CallExpr>(DeclExp)) {
116 Ctx.NumArgs = CE->getNumArgs();
117 Ctx.FunArgs = CE->getArgs();
118 } else if (const CXXConstructExpr *CE =
119 dyn_cast<CXXConstructExpr>(DeclExp)) {
120 Ctx.SelfArg = nullptr; // Will be set below
121 Ctx.NumArgs = CE->getNumArgs();
122 Ctx.FunArgs = CE->getArgs();
123 } else if (D && isa<CXXDestructorDecl>(D)) {
124 // There's no such thing as a "destructor call" in the AST.
125 Ctx.SelfArg = DeclExp;
128 // Hack to handle constructors, where self cannot be recovered from
130 if (SelfDecl && !Ctx.SelfArg) {
131 DeclRefExpr SelfDRE(SelfDecl, false, SelfDecl->getType(), VK_LValue,
132 SelfDecl->getLocation());
133 Ctx.SelfArg = &SelfDRE;
135 // If the attribute has no arguments, then assume the argument is "this".
137 return translateAttrExpr(Ctx.SelfArg, nullptr);
138 else // For most attributes.
139 return translateAttrExpr(AttrExp, &Ctx);
142 // If the attribute has no arguments, then assume the argument is "this".
144 return translateAttrExpr(Ctx.SelfArg, nullptr);
145 else // For most attributes.
146 return translateAttrExpr(AttrExp, &Ctx);
149 /// \brief Translate a clang expression in an attribute to a til::SExpr.
150 // This assumes a CallingContext has already been created.
151 CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
152 CallingContext *Ctx) {
154 return CapabilityExpr(nullptr, false);
156 if (auto* SLit = dyn_cast<StringLiteral>(AttrExp)) {
157 if (SLit->getString() == StringRef("*"))
158 // The "*" expr is a universal lock, which essentially turns off
159 // checks until it is removed from the lockset.
160 return CapabilityExpr(new (Arena) til::Wildcard(), false);
162 // Ignore other string literals for now.
163 return CapabilityExpr(nullptr, false);
167 if (auto *OE = dyn_cast<CXXOperatorCallExpr>(AttrExp)) {
168 if (OE->getOperator() == OO_Exclaim) {
170 AttrExp = OE->getArg(0);
173 else if (auto *UO = dyn_cast<UnaryOperator>(AttrExp)) {
174 if (UO->getOpcode() == UO_LNot) {
176 AttrExp = UO->getSubExpr();
180 til::SExpr *E = translate(AttrExp, Ctx);
182 // Trap mutex expressions like nullptr, or 0.
183 // Any literal value is nonsense.
184 if (!E || isa<til::Literal>(E))
185 return CapabilityExpr(nullptr, false);
187 // Hack to deal with smart pointers -- strip off top-level pointer casts.
188 if (auto *CE = dyn_cast_or_null<til::Cast>(E)) {
189 if (CE->castOpcode() == til::CAST_objToPtr)
190 return CapabilityExpr(CE->expr(), Neg);
192 return CapabilityExpr(E, Neg);
195 // Translate a clang statement or expression to a TIL expression.
196 // Also performs substitution of variables; Ctx provides the context.
197 // Dispatches on the type of S.
198 til::SExpr *SExprBuilder::translate(const Stmt *S, CallingContext *Ctx) {
202 // Check if S has already been translated and cached.
203 // This handles the lookup of SSA names for DeclRefExprs here.
204 if (til::SExpr *E = lookupStmt(S))
207 switch (S->getStmtClass()) {
208 case Stmt::DeclRefExprClass:
209 return translateDeclRefExpr(cast<DeclRefExpr>(S), Ctx);
210 case Stmt::CXXThisExprClass:
211 return translateCXXThisExpr(cast<CXXThisExpr>(S), Ctx);
212 case Stmt::MemberExprClass:
213 return translateMemberExpr(cast<MemberExpr>(S), Ctx);
214 case Stmt::CallExprClass:
215 return translateCallExpr(cast<CallExpr>(S), Ctx);
216 case Stmt::CXXMemberCallExprClass:
217 return translateCXXMemberCallExpr(cast<CXXMemberCallExpr>(S), Ctx);
218 case Stmt::CXXOperatorCallExprClass:
219 return translateCXXOperatorCallExpr(cast<CXXOperatorCallExpr>(S), Ctx);
220 case Stmt::UnaryOperatorClass:
221 return translateUnaryOperator(cast<UnaryOperator>(S), Ctx);
222 case Stmt::BinaryOperatorClass:
223 case Stmt::CompoundAssignOperatorClass:
224 return translateBinaryOperator(cast<BinaryOperator>(S), Ctx);
226 case Stmt::ArraySubscriptExprClass:
227 return translateArraySubscriptExpr(cast<ArraySubscriptExpr>(S), Ctx);
228 case Stmt::ConditionalOperatorClass:
229 return translateAbstractConditionalOperator(
230 cast<ConditionalOperator>(S), Ctx);
231 case Stmt::BinaryConditionalOperatorClass:
232 return translateAbstractConditionalOperator(
233 cast<BinaryConditionalOperator>(S), Ctx);
235 // We treat these as no-ops
236 case Stmt::ParenExprClass:
237 return translate(cast<ParenExpr>(S)->getSubExpr(), Ctx);
238 case Stmt::ExprWithCleanupsClass:
239 return translate(cast<ExprWithCleanups>(S)->getSubExpr(), Ctx);
240 case Stmt::CXXBindTemporaryExprClass:
241 return translate(cast<CXXBindTemporaryExpr>(S)->getSubExpr(), Ctx);
243 // Collect all literals
244 case Stmt::CharacterLiteralClass:
245 case Stmt::CXXNullPtrLiteralExprClass:
246 case Stmt::GNUNullExprClass:
247 case Stmt::CXXBoolLiteralExprClass:
248 case Stmt::FloatingLiteralClass:
249 case Stmt::ImaginaryLiteralClass:
250 case Stmt::IntegerLiteralClass:
251 case Stmt::StringLiteralClass:
252 case Stmt::ObjCStringLiteralClass:
253 return new (Arena) til::Literal(cast<Expr>(S));
255 case Stmt::DeclStmtClass:
256 return translateDeclStmt(cast<DeclStmt>(S), Ctx);
260 if (const CastExpr *CE = dyn_cast<CastExpr>(S))
261 return translateCastExpr(CE, Ctx);
263 return new (Arena) til::Undefined(S);
266 til::SExpr *SExprBuilder::translateDeclRefExpr(const DeclRefExpr *DRE,
267 CallingContext *Ctx) {
268 const ValueDecl *VD = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
270 // Function parameters require substitution and/or renaming.
271 if (const ParmVarDecl *PV = dyn_cast_or_null<ParmVarDecl>(VD)) {
272 const FunctionDecl *FD =
273 cast<FunctionDecl>(PV->getDeclContext())->getCanonicalDecl();
274 unsigned I = PV->getFunctionScopeIndex();
276 if (Ctx && Ctx->FunArgs && FD == Ctx->AttrDecl->getCanonicalDecl()) {
277 // Substitute call arguments for references to function parameters
278 assert(I < Ctx->NumArgs);
279 return translate(Ctx->FunArgs[I], Ctx->Prev);
281 // Map the param back to the param of the original function declaration
282 // for consistent comparisons.
283 VD = FD->getParamDecl(I);
286 // For non-local variables, treat it as a reference to a named object.
287 return new (Arena) til::LiteralPtr(VD);
290 til::SExpr *SExprBuilder::translateCXXThisExpr(const CXXThisExpr *TE,
291 CallingContext *Ctx) {
292 // Substitute for 'this'
293 if (Ctx && Ctx->SelfArg)
294 return translate(Ctx->SelfArg, Ctx->Prev);
295 assert(SelfVar && "We have no variable for 'this'!");
299 static const ValueDecl *getValueDeclFromSExpr(const til::SExpr *E) {
300 if (auto *V = dyn_cast<til::Variable>(E))
301 return V->clangDecl();
302 if (auto *Ph = dyn_cast<til::Phi>(E))
303 return Ph->clangDecl();
304 if (auto *P = dyn_cast<til::Project>(E))
305 return P->clangDecl();
306 if (auto *L = dyn_cast<til::LiteralPtr>(E))
307 return L->clangDecl();
311 static bool hasCppPointerType(const til::SExpr *E) {
312 auto *VD = getValueDeclFromSExpr(E);
313 if (VD && VD->getType()->isPointerType())
315 if (auto *C = dyn_cast<til::Cast>(E))
316 return C->castOpcode() == til::CAST_objToPtr;
321 // Grab the very first declaration of virtual method D
322 static const CXXMethodDecl *getFirstVirtualDecl(const CXXMethodDecl *D) {
324 D = D->getCanonicalDecl();
325 CXXMethodDecl::method_iterator I = D->begin_overridden_methods(),
326 E = D->end_overridden_methods();
328 return D; // Method does not override anything
329 D = *I; // FIXME: this does not work with multiple inheritance.
334 til::SExpr *SExprBuilder::translateMemberExpr(const MemberExpr *ME,
335 CallingContext *Ctx) {
336 til::SExpr *BE = translate(ME->getBase(), Ctx);
337 til::SExpr *E = new (Arena) til::SApply(BE);
340 cast<ValueDecl>(ME->getMemberDecl()->getCanonicalDecl());
341 if (auto *VD = dyn_cast<CXXMethodDecl>(D))
342 D = getFirstVirtualDecl(VD);
344 til::Project *P = new (Arena) til::Project(E, D);
345 if (hasCppPointerType(BE))
350 til::SExpr *SExprBuilder::translateCallExpr(const CallExpr *CE,
353 if (CapabilityExprMode) {
354 // Handle LOCK_RETURNED
355 const FunctionDecl *FD = CE->getDirectCallee()->getMostRecentDecl();
356 if (LockReturnedAttr* At = FD->getAttr<LockReturnedAttr>()) {
357 CallingContext LRCallCtx(Ctx);
358 LRCallCtx.AttrDecl = CE->getDirectCallee();
359 LRCallCtx.SelfArg = SelfE;
360 LRCallCtx.NumArgs = CE->getNumArgs();
361 LRCallCtx.FunArgs = CE->getArgs();
362 return const_cast<til::SExpr*>(
363 translateAttrExpr(At->getArg(), &LRCallCtx).sexpr());
367 til::SExpr *E = translate(CE->getCallee(), Ctx);
368 for (const auto *Arg : CE->arguments()) {
369 til::SExpr *A = translate(Arg, Ctx);
370 E = new (Arena) til::Apply(E, A);
372 return new (Arena) til::Call(E, CE);
375 til::SExpr *SExprBuilder::translateCXXMemberCallExpr(
376 const CXXMemberCallExpr *ME, CallingContext *Ctx) {
377 if (CapabilityExprMode) {
378 // Ignore calls to get() on smart pointers.
379 if (ME->getMethodDecl()->getNameAsString() == "get" &&
380 ME->getNumArgs() == 0) {
381 auto *E = translate(ME->getImplicitObjectArgument(), Ctx);
382 return new (Arena) til::Cast(til::CAST_objToPtr, E);
386 return translateCallExpr(cast<CallExpr>(ME), Ctx,
387 ME->getImplicitObjectArgument());
390 til::SExpr *SExprBuilder::translateCXXOperatorCallExpr(
391 const CXXOperatorCallExpr *OCE, CallingContext *Ctx) {
392 if (CapabilityExprMode) {
393 // Ignore operator * and operator -> on smart pointers.
394 OverloadedOperatorKind k = OCE->getOperator();
395 if (k == OO_Star || k == OO_Arrow) {
396 auto *E = translate(OCE->getArg(0), Ctx);
397 return new (Arena) til::Cast(til::CAST_objToPtr, E);
401 return translateCallExpr(cast<CallExpr>(OCE), Ctx);
404 til::SExpr *SExprBuilder::translateUnaryOperator(const UnaryOperator *UO,
405 CallingContext *Ctx) {
406 switch (UO->getOpcode()) {
411 return new (Arena) til::Undefined(UO);
414 if (CapabilityExprMode) {
415 // interpret &Graph::mu_ as an existential.
416 if (DeclRefExpr* DRE = dyn_cast<DeclRefExpr>(UO->getSubExpr())) {
417 if (DRE->getDecl()->isCXXInstanceMember()) {
418 // This is a pointer-to-member expression, e.g. &MyClass::mu_.
419 // We interpret this syntax specially, as a wildcard.
420 auto *W = new (Arena) til::Wildcard();
421 return new (Arena) til::Project(W, DRE->getDecl());
425 // otherwise, & is a no-op
426 return translate(UO->getSubExpr(), Ctx);
429 // We treat these as no-ops
432 return translate(UO->getSubExpr(), Ctx);
436 til::UnaryOp(til::UOP_Minus, translate(UO->getSubExpr(), Ctx));
439 til::UnaryOp(til::UOP_BitNot, translate(UO->getSubExpr(), Ctx));
442 til::UnaryOp(til::UOP_LogicNot, translate(UO->getSubExpr(), Ctx));
444 // Currently unsupported
449 return new (Arena) til::Undefined(UO);
451 return new (Arena) til::Undefined(UO);
454 til::SExpr *SExprBuilder::translateBinOp(til::TIL_BinaryOpcode Op,
455 const BinaryOperator *BO,
456 CallingContext *Ctx, bool Reverse) {
457 til::SExpr *E0 = translate(BO->getLHS(), Ctx);
458 til::SExpr *E1 = translate(BO->getRHS(), Ctx);
460 return new (Arena) til::BinaryOp(Op, E1, E0);
462 return new (Arena) til::BinaryOp(Op, E0, E1);
465 til::SExpr *SExprBuilder::translateBinAssign(til::TIL_BinaryOpcode Op,
466 const BinaryOperator *BO,
469 const Expr *LHS = BO->getLHS();
470 const Expr *RHS = BO->getRHS();
471 til::SExpr *E0 = translate(LHS, Ctx);
472 til::SExpr *E1 = translate(RHS, Ctx);
474 const ValueDecl *VD = nullptr;
475 til::SExpr *CV = nullptr;
476 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(LHS)) {
478 CV = lookupVarDecl(VD);
482 til::SExpr *Arg = CV ? CV : new (Arena) til::Load(E0);
483 E1 = new (Arena) til::BinaryOp(Op, Arg, E1);
484 E1 = addStatement(E1, nullptr, VD);
487 return updateVarDecl(VD, E1);
488 return new (Arena) til::Store(E0, E1);
491 til::SExpr *SExprBuilder::translateBinaryOperator(const BinaryOperator *BO,
492 CallingContext *Ctx) {
493 switch (BO->getOpcode()) {
496 return new (Arena) til::Undefined(BO);
498 case BO_Mul: return translateBinOp(til::BOP_Mul, BO, Ctx);
499 case BO_Div: return translateBinOp(til::BOP_Div, BO, Ctx);
500 case BO_Rem: return translateBinOp(til::BOP_Rem, BO, Ctx);
501 case BO_Add: return translateBinOp(til::BOP_Add, BO, Ctx);
502 case BO_Sub: return translateBinOp(til::BOP_Sub, BO, Ctx);
503 case BO_Shl: return translateBinOp(til::BOP_Shl, BO, Ctx);
504 case BO_Shr: return translateBinOp(til::BOP_Shr, BO, Ctx);
505 case BO_LT: return translateBinOp(til::BOP_Lt, BO, Ctx);
506 case BO_GT: return translateBinOp(til::BOP_Lt, BO, Ctx, true);
507 case BO_LE: return translateBinOp(til::BOP_Leq, BO, Ctx);
508 case BO_GE: return translateBinOp(til::BOP_Leq, BO, Ctx, true);
509 case BO_EQ: return translateBinOp(til::BOP_Eq, BO, Ctx);
510 case BO_NE: return translateBinOp(til::BOP_Neq, BO, Ctx);
511 case BO_And: return translateBinOp(til::BOP_BitAnd, BO, Ctx);
512 case BO_Xor: return translateBinOp(til::BOP_BitXor, BO, Ctx);
513 case BO_Or: return translateBinOp(til::BOP_BitOr, BO, Ctx);
514 case BO_LAnd: return translateBinOp(til::BOP_LogicAnd, BO, Ctx);
515 case BO_LOr: return translateBinOp(til::BOP_LogicOr, BO, Ctx);
517 case BO_Assign: return translateBinAssign(til::BOP_Eq, BO, Ctx, true);
518 case BO_MulAssign: return translateBinAssign(til::BOP_Mul, BO, Ctx);
519 case BO_DivAssign: return translateBinAssign(til::BOP_Div, BO, Ctx);
520 case BO_RemAssign: return translateBinAssign(til::BOP_Rem, BO, Ctx);
521 case BO_AddAssign: return translateBinAssign(til::BOP_Add, BO, Ctx);
522 case BO_SubAssign: return translateBinAssign(til::BOP_Sub, BO, Ctx);
523 case BO_ShlAssign: return translateBinAssign(til::BOP_Shl, BO, Ctx);
524 case BO_ShrAssign: return translateBinAssign(til::BOP_Shr, BO, Ctx);
525 case BO_AndAssign: return translateBinAssign(til::BOP_BitAnd, BO, Ctx);
526 case BO_XorAssign: return translateBinAssign(til::BOP_BitXor, BO, Ctx);
527 case BO_OrAssign: return translateBinAssign(til::BOP_BitOr, BO, Ctx);
530 // The clang CFG should have already processed both sides.
531 return translate(BO->getRHS(), Ctx);
533 return new (Arena) til::Undefined(BO);
536 til::SExpr *SExprBuilder::translateCastExpr(const CastExpr *CE,
537 CallingContext *Ctx) {
538 clang::CastKind K = CE->getCastKind();
540 case CK_LValueToRValue: {
541 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
542 til::SExpr *E0 = lookupVarDecl(DRE->getDecl());
546 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
548 // FIXME!! -- get Load working properly
549 // return new (Arena) til::Load(E0);
552 case CK_DerivedToBase:
553 case CK_UncheckedDerivedToBase:
554 case CK_ArrayToPointerDecay:
555 case CK_FunctionToPointerDecay: {
556 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
560 // FIXME: handle different kinds of casts.
561 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
562 if (CapabilityExprMode)
564 return new (Arena) til::Cast(til::CAST_none, E0);
570 SExprBuilder::translateArraySubscriptExpr(const ArraySubscriptExpr *E,
571 CallingContext *Ctx) {
572 til::SExpr *E0 = translate(E->getBase(), Ctx);
573 til::SExpr *E1 = translate(E->getIdx(), Ctx);
574 return new (Arena) til::ArrayIndex(E0, E1);
578 SExprBuilder::translateAbstractConditionalOperator(
579 const AbstractConditionalOperator *CO, CallingContext *Ctx) {
580 auto *C = translate(CO->getCond(), Ctx);
581 auto *T = translate(CO->getTrueExpr(), Ctx);
582 auto *E = translate(CO->getFalseExpr(), Ctx);
583 return new (Arena) til::IfThenElse(C, T, E);
587 SExprBuilder::translateDeclStmt(const DeclStmt *S, CallingContext *Ctx) {
588 DeclGroupRef DGrp = S->getDeclGroup();
589 for (DeclGroupRef::iterator I = DGrp.begin(), E = DGrp.end(); I != E; ++I) {
590 if (VarDecl *VD = dyn_cast_or_null<VarDecl>(*I)) {
591 Expr *E = VD->getInit();
592 til::SExpr* SE = translate(E, Ctx);
594 // Add local variables with trivial type to the variable map
595 QualType T = VD->getType();
596 if (T.isTrivialType(VD->getASTContext())) {
597 return addVarDecl(VD, SE);
607 // If (E) is non-trivial, then add it to the current basic block, and
608 // update the statement map so that S refers to E. Returns a new variable
610 // If E is trivial returns E.
611 til::SExpr *SExprBuilder::addStatement(til::SExpr* E, const Stmt *S,
612 const ValueDecl *VD) {
613 if (!E || !CurrentBB || E->block() || til::ThreadSafetyTIL::isTrivial(E))
616 E = new (Arena) til::Variable(E, VD);
617 CurrentInstructions.push_back(E);
623 // Returns the current value of VD, if known, and nullptr otherwise.
624 til::SExpr *SExprBuilder::lookupVarDecl(const ValueDecl *VD) {
625 auto It = LVarIdxMap.find(VD);
626 if (It != LVarIdxMap.end()) {
627 assert(CurrentLVarMap[It->second].first == VD);
628 return CurrentLVarMap[It->second].second;
633 // if E is a til::Variable, update its clangDecl.
634 static void maybeUpdateVD(til::SExpr *E, const ValueDecl *VD) {
637 if (til::Variable *V = dyn_cast<til::Variable>(E)) {
643 // Adds a new variable declaration.
644 til::SExpr *SExprBuilder::addVarDecl(const ValueDecl *VD, til::SExpr *E) {
645 maybeUpdateVD(E, VD);
646 LVarIdxMap.insert(std::make_pair(VD, CurrentLVarMap.size()));
647 CurrentLVarMap.makeWritable();
648 CurrentLVarMap.push_back(std::make_pair(VD, E));
652 // Updates a current variable declaration. (E.g. by assignment)
653 til::SExpr *SExprBuilder::updateVarDecl(const ValueDecl *VD, til::SExpr *E) {
654 maybeUpdateVD(E, VD);
655 auto It = LVarIdxMap.find(VD);
656 if (It == LVarIdxMap.end()) {
657 til::SExpr *Ptr = new (Arena) til::LiteralPtr(VD);
658 til::SExpr *St = new (Arena) til::Store(Ptr, E);
661 CurrentLVarMap.makeWritable();
662 CurrentLVarMap.elem(It->second).second = E;
666 // Make a Phi node in the current block for the i^th variable in CurrentVarMap.
667 // If E != null, sets Phi[CurrentBlockInfo->ArgIndex] = E.
668 // If E == null, this is a backedge and will be set later.
669 void SExprBuilder::makePhiNodeVar(unsigned i, unsigned NPreds, til::SExpr *E) {
670 unsigned ArgIndex = CurrentBlockInfo->ProcessedPredecessors;
671 assert(ArgIndex > 0 && ArgIndex < NPreds);
673 til::SExpr *CurrE = CurrentLVarMap[i].second;
674 if (CurrE->block() == CurrentBB) {
675 // We already have a Phi node in the current block,
676 // so just add the new variable to the Phi node.
677 til::Phi *Ph = dyn_cast<til::Phi>(CurrE);
678 assert(Ph && "Expecting Phi node.");
680 Ph->values()[ArgIndex] = E;
684 // Make a new phi node: phi(..., E)
685 // All phi args up to the current index are set to the current value.
686 til::Phi *Ph = new (Arena) til::Phi(Arena, NPreds);
687 Ph->values().setValues(NPreds, nullptr);
688 for (unsigned PIdx = 0; PIdx < ArgIndex; ++PIdx)
689 Ph->values()[PIdx] = CurrE;
691 Ph->values()[ArgIndex] = E;
692 Ph->setClangDecl(CurrentLVarMap[i].first);
693 // If E is from a back-edge, or either E or CurrE are incomplete, then
694 // mark this node as incomplete; we may need to remove it later.
695 if (!E || isIncompletePhi(E) || isIncompletePhi(CurrE)) {
696 Ph->setStatus(til::Phi::PH_Incomplete);
699 // Add Phi node to current block, and update CurrentLVarMap[i]
700 CurrentArguments.push_back(Ph);
701 if (Ph->status() == til::Phi::PH_Incomplete)
702 IncompleteArgs.push_back(Ph);
704 CurrentLVarMap.makeWritable();
705 CurrentLVarMap.elem(i).second = Ph;
708 // Merge values from Map into the current variable map.
709 // This will construct Phi nodes in the current basic block as necessary.
710 void SExprBuilder::mergeEntryMap(LVarDefinitionMap Map) {
711 assert(CurrentBlockInfo && "Not processing a block!");
713 if (!CurrentLVarMap.valid()) {
714 // Steal Map, using copy-on-write.
715 CurrentLVarMap = std::move(Map);
718 if (CurrentLVarMap.sameAs(Map))
719 return; // Easy merge: maps from different predecessors are unchanged.
721 unsigned NPreds = CurrentBB->numPredecessors();
722 unsigned ESz = CurrentLVarMap.size();
723 unsigned MSz = Map.size();
724 unsigned Sz = std::min(ESz, MSz);
726 for (unsigned i=0; i<Sz; ++i) {
727 if (CurrentLVarMap[i].first != Map[i].first) {
728 // We've reached the end of variables in common.
729 CurrentLVarMap.makeWritable();
730 CurrentLVarMap.downsize(i);
733 if (CurrentLVarMap[i].second != Map[i].second)
734 makePhiNodeVar(i, NPreds, Map[i].second);
737 CurrentLVarMap.makeWritable();
738 CurrentLVarMap.downsize(Map.size());
742 // Merge a back edge into the current variable map.
743 // This will create phi nodes for all variables in the variable map.
744 void SExprBuilder::mergeEntryMapBackEdge() {
745 // We don't have definitions for variables on the backedge, because we
746 // haven't gotten that far in the CFG. Thus, when encountering a back edge,
747 // we conservatively create Phi nodes for all variables. Unnecessary Phi
748 // nodes will be marked as incomplete, and stripped out at the end.
750 // An Phi node is unnecessary if it only refers to itself and one other
751 // variable, e.g. x = Phi(y, y, x) can be reduced to x = y.
753 assert(CurrentBlockInfo && "Not processing a block!");
755 if (CurrentBlockInfo->HasBackEdges)
757 CurrentBlockInfo->HasBackEdges = true;
759 CurrentLVarMap.makeWritable();
760 unsigned Sz = CurrentLVarMap.size();
761 unsigned NPreds = CurrentBB->numPredecessors();
763 for (unsigned i=0; i < Sz; ++i) {
764 makePhiNodeVar(i, NPreds, nullptr);
768 // Update the phi nodes that were initially created for a back edge
769 // once the variable definitions have been computed.
770 // I.e., merge the current variable map into the phi nodes for Blk.
771 void SExprBuilder::mergePhiNodesBackEdge(const CFGBlock *Blk) {
772 til::BasicBlock *BB = lookupBlock(Blk);
773 unsigned ArgIndex = BBInfo[Blk->getBlockID()].ProcessedPredecessors;
774 assert(ArgIndex > 0 && ArgIndex < BB->numPredecessors());
776 for (til::SExpr *PE : BB->arguments()) {
777 til::Phi *Ph = dyn_cast_or_null<til::Phi>(PE);
778 assert(Ph && "Expecting Phi Node.");
779 assert(Ph->values()[ArgIndex] == nullptr && "Wrong index for back edge.");
781 til::SExpr *E = lookupVarDecl(Ph->clangDecl());
782 assert(E && "Couldn't find local variable for Phi node.");
783 Ph->values()[ArgIndex] = E;
787 void SExprBuilder::enterCFG(CFG *Cfg, const NamedDecl *D,
788 const CFGBlock *First) {
789 // Perform initial setup operations.
790 unsigned NBlocks = Cfg->getNumBlockIDs();
791 Scfg = new (Arena) til::SCFG(Arena, NBlocks);
793 // allocate all basic blocks immediately, to handle forward references.
794 BBInfo.resize(NBlocks);
795 BlockMap.resize(NBlocks, nullptr);
796 // create map from clang blockID to til::BasicBlocks
797 for (auto *B : *Cfg) {
798 auto *BB = new (Arena) til::BasicBlock(Arena);
799 BB->reserveInstructions(B->size());
800 BlockMap[B->getBlockID()] = BB;
803 CurrentBB = lookupBlock(&Cfg->getEntry());
804 auto Parms = isa<ObjCMethodDecl>(D) ? cast<ObjCMethodDecl>(D)->parameters()
805 : cast<FunctionDecl>(D)->parameters();
806 for (auto *Pm : Parms) {
807 QualType T = Pm->getType();
808 if (!T.isTrivialType(Pm->getASTContext()))
811 // Add parameters to local variable map.
812 // FIXME: right now we emulate params with loads; that should be fixed.
813 til::SExpr *Lp = new (Arena) til::LiteralPtr(Pm);
814 til::SExpr *Ld = new (Arena) til::Load(Lp);
815 til::SExpr *V = addStatement(Ld, nullptr, Pm);
820 void SExprBuilder::enterCFGBlock(const CFGBlock *B) {
821 // Intialize TIL basic block and add it to the CFG.
822 CurrentBB = lookupBlock(B);
823 CurrentBB->reservePredecessors(B->pred_size());
824 Scfg->add(CurrentBB);
826 CurrentBlockInfo = &BBInfo[B->getBlockID()];
828 // CurrentLVarMap is moved to ExitMap on block exit.
829 // FIXME: the entry block will hold function parameters.
830 // assert(!CurrentLVarMap.valid() && "CurrentLVarMap already initialized.");
833 void SExprBuilder::handlePredecessor(const CFGBlock *Pred) {
834 // Compute CurrentLVarMap on entry from ExitMaps of predecessors
836 CurrentBB->addPredecessor(BlockMap[Pred->getBlockID()]);
837 BlockInfo *PredInfo = &BBInfo[Pred->getBlockID()];
838 assert(PredInfo->UnprocessedSuccessors > 0);
840 if (--PredInfo->UnprocessedSuccessors == 0)
841 mergeEntryMap(std::move(PredInfo->ExitMap));
843 mergeEntryMap(PredInfo->ExitMap.clone());
845 ++CurrentBlockInfo->ProcessedPredecessors;
848 void SExprBuilder::handlePredecessorBackEdge(const CFGBlock *Pred) {
849 mergeEntryMapBackEdge();
852 void SExprBuilder::enterCFGBlockBody(const CFGBlock *B) {
853 // The merge*() methods have created arguments.
854 // Push those arguments onto the basic block.
855 CurrentBB->arguments().reserve(
856 static_cast<unsigned>(CurrentArguments.size()), Arena);
857 for (auto *A : CurrentArguments)
858 CurrentBB->addArgument(A);
861 void SExprBuilder::handleStatement(const Stmt *S) {
862 til::SExpr *E = translate(S, nullptr);
866 void SExprBuilder::handleDestructorCall(const VarDecl *VD,
867 const CXXDestructorDecl *DD) {
868 til::SExpr *Sf = new (Arena) til::LiteralPtr(VD);
869 til::SExpr *Dr = new (Arena) til::LiteralPtr(DD);
870 til::SExpr *Ap = new (Arena) til::Apply(Dr, Sf);
871 til::SExpr *E = new (Arena) til::Call(Ap);
872 addStatement(E, nullptr);
875 void SExprBuilder::exitCFGBlockBody(const CFGBlock *B) {
876 CurrentBB->instructions().reserve(
877 static_cast<unsigned>(CurrentInstructions.size()), Arena);
878 for (auto *V : CurrentInstructions)
879 CurrentBB->addInstruction(V);
881 // Create an appropriate terminator
882 unsigned N = B->succ_size();
883 auto It = B->succ_begin();
885 til::BasicBlock *BB = *It ? lookupBlock(*It) : nullptr;
887 unsigned Idx = BB ? BB->findPredecessorIndex(CurrentBB) : 0;
888 auto *Tm = new (Arena) til::Goto(BB, Idx);
889 CurrentBB->setTerminator(Tm);
892 til::SExpr *C = translate(B->getTerminatorCondition(true), nullptr);
893 til::BasicBlock *BB1 = *It ? lookupBlock(*It) : nullptr;
895 til::BasicBlock *BB2 = *It ? lookupBlock(*It) : nullptr;
896 // FIXME: make sure these arent' critical edges.
897 auto *Tm = new (Arena) til::Branch(C, BB1, BB2);
898 CurrentBB->setTerminator(Tm);
902 void SExprBuilder::handleSuccessor(const CFGBlock *Succ) {
903 ++CurrentBlockInfo->UnprocessedSuccessors;
906 void SExprBuilder::handleSuccessorBackEdge(const CFGBlock *Succ) {
907 mergePhiNodesBackEdge(Succ);
908 ++BBInfo[Succ->getBlockID()].ProcessedPredecessors;
911 void SExprBuilder::exitCFGBlock(const CFGBlock *B) {
912 CurrentArguments.clear();
913 CurrentInstructions.clear();
914 CurrentBlockInfo->ExitMap = std::move(CurrentLVarMap);
916 CurrentBlockInfo = nullptr;
919 void SExprBuilder::exitCFG(const CFGBlock *Last) {
920 for (auto *Ph : IncompleteArgs) {
921 if (Ph->status() == til::Phi::PH_Incomplete)
922 simplifyIncompleteArg(Ph);
925 CurrentArguments.clear();
926 CurrentInstructions.clear();
927 IncompleteArgs.clear();
931 void printSCFG(CFGWalker &Walker) {
932 llvm::BumpPtrAllocator Bpa;
933 til::MemRegionRef Arena(&Bpa);
934 SExprBuilder SxBuilder(Arena);
935 til::SCFG *Scfg = SxBuilder.buildCFG(Walker);
936 TILPrinter::print(Scfg, llvm::errs());