1 //===- ThreadSafetyCommon.cpp ---------------------------------------------===//
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/Decl.h"
17 #include "clang/AST/DeclCXX.h"
18 #include "clang/AST/DeclGroup.h"
19 #include "clang/AST/DeclObjC.h"
20 #include "clang/AST/Expr.h"
21 #include "clang/AST/ExprCXX.h"
22 #include "clang/AST/OperationKinds.h"
23 #include "clang/AST/Stmt.h"
24 #include "clang/AST/Type.h"
25 #include "clang/Analysis/Analyses/ThreadSafetyTIL.h"
26 #include "clang/Analysis/CFG.h"
27 #include "clang/Basic/LLVM.h"
28 #include "clang/Basic/OperatorKinds.h"
29 #include "clang/Basic/Specifiers.h"
30 #include "llvm/ADT/StringRef.h"
31 #include "llvm/Support/Casting.h"
37 using namespace clang;
38 using namespace threadSafety;
40 // From ThreadSafetyUtil.h
41 std::string threadSafety::getSourceLiteralString(const Expr *CE) {
42 switch (CE->getStmtClass()) {
43 case Stmt::IntegerLiteralClass:
44 return cast<IntegerLiteral>(CE)->getValue().toString(10, true);
45 case Stmt::StringLiteralClass: {
46 std::string ret("\"");
47 ret += cast<StringLiteral>(CE)->getString();
51 case Stmt::CharacterLiteralClass:
52 case Stmt::CXXNullPtrLiteralExprClass:
53 case Stmt::GNUNullExprClass:
54 case Stmt::CXXBoolLiteralExprClass:
55 case Stmt::FloatingLiteralClass:
56 case Stmt::ImaginaryLiteralClass:
57 case Stmt::ObjCStringLiteralClass:
63 // Return true if E is a variable that points to an incomplete Phi node.
64 static bool isIncompletePhi(const til::SExpr *E) {
65 if (const auto *Ph = dyn_cast<til::Phi>(E))
66 return Ph->status() == til::Phi::PH_Incomplete;
70 using CallingContext = SExprBuilder::CallingContext;
72 til::SExpr *SExprBuilder::lookupStmt(const Stmt *S) {
73 auto It = SMap.find(S);
79 til::SCFG *SExprBuilder::buildCFG(CFGWalker &Walker) {
84 static bool isCalleeArrow(const Expr *E) {
85 const auto *ME = dyn_cast<MemberExpr>(E->IgnoreParenCasts());
86 return ME ? ME->isArrow() : false;
89 /// Translate a clang expression in an attribute to a til::SExpr.
90 /// Constructs the context from D, DeclExp, and SelfDecl.
92 /// \param AttrExp The expression to translate.
93 /// \param D The declaration to which the attribute is attached.
94 /// \param DeclExp An expression involving the Decl to which the attribute
95 /// is attached. E.g. the call to a function.
96 CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
100 // If we are processing a raw attribute expression, with no substitutions.
102 return translateAttrExpr(AttrExp, nullptr);
104 CallingContext Ctx(nullptr, D);
106 // Examine DeclExp to find SelfArg and FunArgs, which are used to substitute
107 // for formal parameters when we call buildMutexID later.
108 if (const auto *ME = dyn_cast<MemberExpr>(DeclExp)) {
109 Ctx.SelfArg = ME->getBase();
110 Ctx.SelfArrow = ME->isArrow();
111 } else if (const auto *CE = dyn_cast<CXXMemberCallExpr>(DeclExp)) {
112 Ctx.SelfArg = CE->getImplicitObjectArgument();
113 Ctx.SelfArrow = isCalleeArrow(CE->getCallee());
114 Ctx.NumArgs = CE->getNumArgs();
115 Ctx.FunArgs = CE->getArgs();
116 } else if (const auto *CE = dyn_cast<CallExpr>(DeclExp)) {
117 Ctx.NumArgs = CE->getNumArgs();
118 Ctx.FunArgs = CE->getArgs();
119 } else if (const auto *CE = 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 /// 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 (const 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 (const auto *OE = dyn_cast<CXXOperatorCallExpr>(AttrExp)) {
168 if (OE->getOperator() == OO_Exclaim) {
170 AttrExp = OE->getArg(0);
173 else if (const 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 (const 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);
242 case Stmt::MaterializeTemporaryExprClass:
243 return translate(cast<MaterializeTemporaryExpr>(S)->GetTemporaryExpr(),
246 // Collect all literals
247 case Stmt::CharacterLiteralClass:
248 case Stmt::CXXNullPtrLiteralExprClass:
249 case Stmt::GNUNullExprClass:
250 case Stmt::CXXBoolLiteralExprClass:
251 case Stmt::FloatingLiteralClass:
252 case Stmt::ImaginaryLiteralClass:
253 case Stmt::IntegerLiteralClass:
254 case Stmt::StringLiteralClass:
255 case Stmt::ObjCStringLiteralClass:
256 return new (Arena) til::Literal(cast<Expr>(S));
258 case Stmt::DeclStmtClass:
259 return translateDeclStmt(cast<DeclStmt>(S), Ctx);
263 if (const auto *CE = dyn_cast<CastExpr>(S))
264 return translateCastExpr(CE, Ctx);
266 return new (Arena) til::Undefined(S);
269 til::SExpr *SExprBuilder::translateDeclRefExpr(const DeclRefExpr *DRE,
270 CallingContext *Ctx) {
271 const auto *VD = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
273 // Function parameters require substitution and/or renaming.
274 if (const auto *PV = dyn_cast_or_null<ParmVarDecl>(VD)) {
276 cast<FunctionDecl>(PV->getDeclContext())->getCanonicalDecl();
277 unsigned I = PV->getFunctionScopeIndex();
279 if (Ctx && Ctx->FunArgs && FD == Ctx->AttrDecl->getCanonicalDecl()) {
280 // Substitute call arguments for references to function parameters
281 assert(I < Ctx->NumArgs);
282 return translate(Ctx->FunArgs[I], Ctx->Prev);
284 // Map the param back to the param of the original function declaration
285 // for consistent comparisons.
286 VD = FD->getParamDecl(I);
289 // For non-local variables, treat it as a reference to a named object.
290 return new (Arena) til::LiteralPtr(VD);
293 til::SExpr *SExprBuilder::translateCXXThisExpr(const CXXThisExpr *TE,
294 CallingContext *Ctx) {
295 // Substitute for 'this'
296 if (Ctx && Ctx->SelfArg)
297 return translate(Ctx->SelfArg, Ctx->Prev);
298 assert(SelfVar && "We have no variable for 'this'!");
302 static const ValueDecl *getValueDeclFromSExpr(const til::SExpr *E) {
303 if (const auto *V = dyn_cast<til::Variable>(E))
304 return V->clangDecl();
305 if (const auto *Ph = dyn_cast<til::Phi>(E))
306 return Ph->clangDecl();
307 if (const auto *P = dyn_cast<til::Project>(E))
308 return P->clangDecl();
309 if (const auto *L = dyn_cast<til::LiteralPtr>(E))
310 return L->clangDecl();
314 static bool hasCppPointerType(const til::SExpr *E) {
315 auto *VD = getValueDeclFromSExpr(E);
316 if (VD && VD->getType()->isPointerType())
318 if (const auto *C = dyn_cast<til::Cast>(E))
319 return C->castOpcode() == til::CAST_objToPtr;
324 // Grab the very first declaration of virtual method D
325 static const CXXMethodDecl *getFirstVirtualDecl(const CXXMethodDecl *D) {
327 D = D->getCanonicalDecl();
328 auto OverriddenMethods = D->overridden_methods();
329 if (OverriddenMethods.begin() == OverriddenMethods.end())
330 return D; // Method does not override anything
331 // FIXME: this does not work with multiple inheritance.
332 D = *OverriddenMethods.begin();
337 til::SExpr *SExprBuilder::translateMemberExpr(const MemberExpr *ME,
338 CallingContext *Ctx) {
339 til::SExpr *BE = translate(ME->getBase(), Ctx);
340 til::SExpr *E = new (Arena) til::SApply(BE);
342 const auto *D = cast<ValueDecl>(ME->getMemberDecl()->getCanonicalDecl());
343 if (const auto *VD = dyn_cast<CXXMethodDecl>(D))
344 D = getFirstVirtualDecl(VD);
346 til::Project *P = new (Arena) til::Project(E, D);
347 if (hasCppPointerType(BE))
352 til::SExpr *SExprBuilder::translateCallExpr(const CallExpr *CE,
355 if (CapabilityExprMode) {
356 // Handle LOCK_RETURNED
357 const FunctionDecl *FD = CE->getDirectCallee()->getMostRecentDecl();
358 if (LockReturnedAttr* At = FD->getAttr<LockReturnedAttr>()) {
359 CallingContext LRCallCtx(Ctx);
360 LRCallCtx.AttrDecl = CE->getDirectCallee();
361 LRCallCtx.SelfArg = SelfE;
362 LRCallCtx.NumArgs = CE->getNumArgs();
363 LRCallCtx.FunArgs = CE->getArgs();
364 return const_cast<til::SExpr *>(
365 translateAttrExpr(At->getArg(), &LRCallCtx).sexpr());
369 til::SExpr *E = translate(CE->getCallee(), Ctx);
370 for (const auto *Arg : CE->arguments()) {
371 til::SExpr *A = translate(Arg, Ctx);
372 E = new (Arena) til::Apply(E, A);
374 return new (Arena) til::Call(E, CE);
377 til::SExpr *SExprBuilder::translateCXXMemberCallExpr(
378 const CXXMemberCallExpr *ME, CallingContext *Ctx) {
379 if (CapabilityExprMode) {
380 // Ignore calls to get() on smart pointers.
381 if (ME->getMethodDecl()->getNameAsString() == "get" &&
382 ME->getNumArgs() == 0) {
383 auto *E = translate(ME->getImplicitObjectArgument(), Ctx);
384 return new (Arena) til::Cast(til::CAST_objToPtr, E);
388 return translateCallExpr(cast<CallExpr>(ME), Ctx,
389 ME->getImplicitObjectArgument());
392 til::SExpr *SExprBuilder::translateCXXOperatorCallExpr(
393 const CXXOperatorCallExpr *OCE, CallingContext *Ctx) {
394 if (CapabilityExprMode) {
395 // Ignore operator * and operator -> on smart pointers.
396 OverloadedOperatorKind k = OCE->getOperator();
397 if (k == OO_Star || k == OO_Arrow) {
398 auto *E = translate(OCE->getArg(0), Ctx);
399 return new (Arena) til::Cast(til::CAST_objToPtr, E);
403 return translateCallExpr(cast<CallExpr>(OCE), Ctx);
406 til::SExpr *SExprBuilder::translateUnaryOperator(const UnaryOperator *UO,
407 CallingContext *Ctx) {
408 switch (UO->getOpcode()) {
413 return new (Arena) til::Undefined(UO);
416 if (CapabilityExprMode) {
417 // interpret &Graph::mu_ as an existential.
418 if (const auto *DRE = dyn_cast<DeclRefExpr>(UO->getSubExpr())) {
419 if (DRE->getDecl()->isCXXInstanceMember()) {
420 // This is a pointer-to-member expression, e.g. &MyClass::mu_.
421 // We interpret this syntax specially, as a wildcard.
422 auto *W = new (Arena) til::Wildcard();
423 return new (Arena) til::Project(W, DRE->getDecl());
427 // otherwise, & is a no-op
428 return translate(UO->getSubExpr(), Ctx);
430 // We treat these as no-ops
433 return translate(UO->getSubExpr(), Ctx);
437 til::UnaryOp(til::UOP_Minus, translate(UO->getSubExpr(), Ctx));
440 til::UnaryOp(til::UOP_BitNot, translate(UO->getSubExpr(), Ctx));
443 til::UnaryOp(til::UOP_LogicNot, translate(UO->getSubExpr(), Ctx));
445 // Currently unsupported
450 return new (Arena) til::Undefined(UO);
452 return new (Arena) til::Undefined(UO);
455 til::SExpr *SExprBuilder::translateBinOp(til::TIL_BinaryOpcode Op,
456 const BinaryOperator *BO,
457 CallingContext *Ctx, bool Reverse) {
458 til::SExpr *E0 = translate(BO->getLHS(), Ctx);
459 til::SExpr *E1 = translate(BO->getRHS(), Ctx);
461 return new (Arena) til::BinaryOp(Op, E1, E0);
463 return new (Arena) til::BinaryOp(Op, E0, E1);
466 til::SExpr *SExprBuilder::translateBinAssign(til::TIL_BinaryOpcode Op,
467 const BinaryOperator *BO,
470 const Expr *LHS = BO->getLHS();
471 const Expr *RHS = BO->getRHS();
472 til::SExpr *E0 = translate(LHS, Ctx);
473 til::SExpr *E1 = translate(RHS, Ctx);
475 const ValueDecl *VD = nullptr;
476 til::SExpr *CV = nullptr;
477 if (const auto *DRE = dyn_cast<DeclRefExpr>(LHS)) {
479 CV = lookupVarDecl(VD);
483 til::SExpr *Arg = CV ? CV : new (Arena) til::Load(E0);
484 E1 = new (Arena) til::BinaryOp(Op, Arg, E1);
485 E1 = addStatement(E1, nullptr, VD);
488 return updateVarDecl(VD, E1);
489 return new (Arena) til::Store(E0, E1);
492 til::SExpr *SExprBuilder::translateBinaryOperator(const BinaryOperator *BO,
493 CallingContext *Ctx) {
494 switch (BO->getOpcode()) {
497 return new (Arena) til::Undefined(BO);
499 case BO_Mul: return translateBinOp(til::BOP_Mul, BO, Ctx);
500 case BO_Div: return translateBinOp(til::BOP_Div, BO, Ctx);
501 case BO_Rem: return translateBinOp(til::BOP_Rem, BO, Ctx);
502 case BO_Add: return translateBinOp(til::BOP_Add, BO, Ctx);
503 case BO_Sub: return translateBinOp(til::BOP_Sub, BO, Ctx);
504 case BO_Shl: return translateBinOp(til::BOP_Shl, BO, Ctx);
505 case BO_Shr: return translateBinOp(til::BOP_Shr, BO, Ctx);
506 case BO_LT: return translateBinOp(til::BOP_Lt, BO, Ctx);
507 case BO_GT: return translateBinOp(til::BOP_Lt, BO, Ctx, true);
508 case BO_LE: return translateBinOp(til::BOP_Leq, BO, Ctx);
509 case BO_GE: return translateBinOp(til::BOP_Leq, BO, Ctx, true);
510 case BO_EQ: return translateBinOp(til::BOP_Eq, BO, Ctx);
511 case BO_NE: return translateBinOp(til::BOP_Neq, BO, Ctx);
512 case BO_Cmp: return translateBinOp(til::BOP_Cmp, BO, Ctx);
513 case BO_And: return translateBinOp(til::BOP_BitAnd, BO, Ctx);
514 case BO_Xor: return translateBinOp(til::BOP_BitXor, BO, Ctx);
515 case BO_Or: return translateBinOp(til::BOP_BitOr, BO, Ctx);
516 case BO_LAnd: return translateBinOp(til::BOP_LogicAnd, BO, Ctx);
517 case BO_LOr: return translateBinOp(til::BOP_LogicOr, BO, Ctx);
519 case BO_Assign: return translateBinAssign(til::BOP_Eq, BO, Ctx, true);
520 case BO_MulAssign: return translateBinAssign(til::BOP_Mul, BO, Ctx);
521 case BO_DivAssign: return translateBinAssign(til::BOP_Div, BO, Ctx);
522 case BO_RemAssign: return translateBinAssign(til::BOP_Rem, BO, Ctx);
523 case BO_AddAssign: return translateBinAssign(til::BOP_Add, BO, Ctx);
524 case BO_SubAssign: return translateBinAssign(til::BOP_Sub, BO, Ctx);
525 case BO_ShlAssign: return translateBinAssign(til::BOP_Shl, BO, Ctx);
526 case BO_ShrAssign: return translateBinAssign(til::BOP_Shr, BO, Ctx);
527 case BO_AndAssign: return translateBinAssign(til::BOP_BitAnd, BO, Ctx);
528 case BO_XorAssign: return translateBinAssign(til::BOP_BitXor, BO, Ctx);
529 case BO_OrAssign: return translateBinAssign(til::BOP_BitOr, BO, Ctx);
532 // The clang CFG should have already processed both sides.
533 return translate(BO->getRHS(), Ctx);
535 return new (Arena) til::Undefined(BO);
538 til::SExpr *SExprBuilder::translateCastExpr(const CastExpr *CE,
539 CallingContext *Ctx) {
540 CastKind K = CE->getCastKind();
542 case CK_LValueToRValue: {
543 if (const auto *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
544 til::SExpr *E0 = lookupVarDecl(DRE->getDecl());
548 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
550 // FIXME!! -- get Load working properly
551 // return new (Arena) til::Load(E0);
554 case CK_DerivedToBase:
555 case CK_UncheckedDerivedToBase:
556 case CK_ArrayToPointerDecay:
557 case CK_FunctionToPointerDecay: {
558 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
562 // FIXME: handle different kinds of casts.
563 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
564 if (CapabilityExprMode)
566 return new (Arena) til::Cast(til::CAST_none, E0);
572 SExprBuilder::translateArraySubscriptExpr(const ArraySubscriptExpr *E,
573 CallingContext *Ctx) {
574 til::SExpr *E0 = translate(E->getBase(), Ctx);
575 til::SExpr *E1 = translate(E->getIdx(), Ctx);
576 return new (Arena) til::ArrayIndex(E0, E1);
580 SExprBuilder::translateAbstractConditionalOperator(
581 const AbstractConditionalOperator *CO, CallingContext *Ctx) {
582 auto *C = translate(CO->getCond(), Ctx);
583 auto *T = translate(CO->getTrueExpr(), Ctx);
584 auto *E = translate(CO->getFalseExpr(), Ctx);
585 return new (Arena) til::IfThenElse(C, T, E);
589 SExprBuilder::translateDeclStmt(const DeclStmt *S, CallingContext *Ctx) {
590 DeclGroupRef DGrp = S->getDeclGroup();
591 for (auto I : DGrp) {
592 if (auto *VD = dyn_cast_or_null<VarDecl>(I)) {
593 Expr *E = VD->getInit();
594 til::SExpr* SE = translate(E, Ctx);
596 // Add local variables with trivial type to the variable map
597 QualType T = VD->getType();
598 if (T.isTrivialType(VD->getASTContext()))
599 return addVarDecl(VD, SE);
608 // If (E) is non-trivial, then add it to the current basic block, and
609 // update the statement map so that S refers to E. Returns a new variable
611 // If E is trivial returns E.
612 til::SExpr *SExprBuilder::addStatement(til::SExpr* E, const Stmt *S,
613 const ValueDecl *VD) {
614 if (!E || !CurrentBB || E->block() || til::ThreadSafetyTIL::isTrivial(E))
617 E = new (Arena) til::Variable(E, VD);
618 CurrentInstructions.push_back(E);
624 // Returns the current value of VD, if known, and nullptr otherwise.
625 til::SExpr *SExprBuilder::lookupVarDecl(const ValueDecl *VD) {
626 auto It = LVarIdxMap.find(VD);
627 if (It != LVarIdxMap.end()) {
628 assert(CurrentLVarMap[It->second].first == VD);
629 return CurrentLVarMap[It->second].second;
634 // if E is a til::Variable, update its clangDecl.
635 static void maybeUpdateVD(til::SExpr *E, const ValueDecl *VD) {
638 if (auto *V = dyn_cast<til::Variable>(E)) {
644 // Adds a new variable declaration.
645 til::SExpr *SExprBuilder::addVarDecl(const ValueDecl *VD, til::SExpr *E) {
646 maybeUpdateVD(E, VD);
647 LVarIdxMap.insert(std::make_pair(VD, CurrentLVarMap.size()));
648 CurrentLVarMap.makeWritable();
649 CurrentLVarMap.push_back(std::make_pair(VD, E));
653 // Updates a current variable declaration. (E.g. by assignment)
654 til::SExpr *SExprBuilder::updateVarDecl(const ValueDecl *VD, til::SExpr *E) {
655 maybeUpdateVD(E, VD);
656 auto It = LVarIdxMap.find(VD);
657 if (It == LVarIdxMap.end()) {
658 til::SExpr *Ptr = new (Arena) til::LiteralPtr(VD);
659 til::SExpr *St = new (Arena) til::Store(Ptr, E);
662 CurrentLVarMap.makeWritable();
663 CurrentLVarMap.elem(It->second).second = E;
667 // Make a Phi node in the current block for the i^th variable in CurrentVarMap.
668 // If E != null, sets Phi[CurrentBlockInfo->ArgIndex] = E.
669 // If E == null, this is a backedge and will be set later.
670 void SExprBuilder::makePhiNodeVar(unsigned i, unsigned NPreds, til::SExpr *E) {
671 unsigned ArgIndex = CurrentBlockInfo->ProcessedPredecessors;
672 assert(ArgIndex > 0 && ArgIndex < NPreds);
674 til::SExpr *CurrE = CurrentLVarMap[i].second;
675 if (CurrE->block() == CurrentBB) {
676 // We already have a Phi node in the current block,
677 // so just add the new variable to the Phi node.
678 auto *Ph = dyn_cast<til::Phi>(CurrE);
679 assert(Ph && "Expecting Phi node.");
681 Ph->values()[ArgIndex] = E;
685 // Make a new phi node: phi(..., E)
686 // All phi args up to the current index are set to the current value.
687 til::Phi *Ph = new (Arena) til::Phi(Arena, NPreds);
688 Ph->values().setValues(NPreds, nullptr);
689 for (unsigned PIdx = 0; PIdx < ArgIndex; ++PIdx)
690 Ph->values()[PIdx] = CurrE;
692 Ph->values()[ArgIndex] = E;
693 Ph->setClangDecl(CurrentLVarMap[i].first);
694 // If E is from a back-edge, or either E or CurrE are incomplete, then
695 // mark this node as incomplete; we may need to remove it later.
696 if (!E || isIncompletePhi(E) || isIncompletePhi(CurrE))
697 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);
767 // Update the phi nodes that were initially created for a back edge
768 // once the variable definitions have been computed.
769 // I.e., merge the current variable map into the phi nodes for Blk.
770 void SExprBuilder::mergePhiNodesBackEdge(const CFGBlock *Blk) {
771 til::BasicBlock *BB = lookupBlock(Blk);
772 unsigned ArgIndex = BBInfo[Blk->getBlockID()].ProcessedPredecessors;
773 assert(ArgIndex > 0 && ArgIndex < BB->numPredecessors());
775 for (til::SExpr *PE : BB->arguments()) {
776 auto *Ph = dyn_cast_or_null<til::Phi>(PE);
777 assert(Ph && "Expecting Phi Node.");
778 assert(Ph->values()[ArgIndex] == nullptr && "Wrong index for back edge.");
780 til::SExpr *E = lookupVarDecl(Ph->clangDecl());
781 assert(E && "Couldn't find local variable for Phi node.");
782 Ph->values()[ArgIndex] = E;
786 void SExprBuilder::enterCFG(CFG *Cfg, const NamedDecl *D,
787 const CFGBlock *First) {
788 // Perform initial setup operations.
789 unsigned NBlocks = Cfg->getNumBlockIDs();
790 Scfg = new (Arena) til::SCFG(Arena, NBlocks);
792 // allocate all basic blocks immediately, to handle forward references.
793 BBInfo.resize(NBlocks);
794 BlockMap.resize(NBlocks, nullptr);
795 // create map from clang blockID to til::BasicBlocks
796 for (auto *B : *Cfg) {
797 auto *BB = new (Arena) til::BasicBlock(Arena);
798 BB->reserveInstructions(B->size());
799 BlockMap[B->getBlockID()] = BB;
802 CurrentBB = lookupBlock(&Cfg->getEntry());
803 auto Parms = isa<ObjCMethodDecl>(D) ? cast<ObjCMethodDecl>(D)->parameters()
804 : cast<FunctionDecl>(D)->parameters();
805 for (auto *Pm : Parms) {
806 QualType T = Pm->getType();
807 if (!T.isTrivialType(Pm->getASTContext()))
810 // Add parameters to local variable map.
811 // FIXME: right now we emulate params with loads; that should be fixed.
812 til::SExpr *Lp = new (Arena) til::LiteralPtr(Pm);
813 til::SExpr *Ld = new (Arena) til::Load(Lp);
814 til::SExpr *V = addStatement(Ld, nullptr, Pm);
819 void SExprBuilder::enterCFGBlock(const CFGBlock *B) {
820 // Initialize TIL basic block and add it to the CFG.
821 CurrentBB = lookupBlock(B);
822 CurrentBB->reservePredecessors(B->pred_size());
823 Scfg->add(CurrentBB);
825 CurrentBlockInfo = &BBInfo[B->getBlockID()];
827 // CurrentLVarMap is moved to ExitMap on block exit.
828 // FIXME: the entry block will hold function parameters.
829 // assert(!CurrentLVarMap.valid() && "CurrentLVarMap already initialized.");
832 void SExprBuilder::handlePredecessor(const CFGBlock *Pred) {
833 // Compute CurrentLVarMap on entry from ExitMaps of predecessors
835 CurrentBB->addPredecessor(BlockMap[Pred->getBlockID()]);
836 BlockInfo *PredInfo = &BBInfo[Pred->getBlockID()];
837 assert(PredInfo->UnprocessedSuccessors > 0);
839 if (--PredInfo->UnprocessedSuccessors == 0)
840 mergeEntryMap(std::move(PredInfo->ExitMap));
842 mergeEntryMap(PredInfo->ExitMap.clone());
844 ++CurrentBlockInfo->ProcessedPredecessors;
847 void SExprBuilder::handlePredecessorBackEdge(const CFGBlock *Pred) {
848 mergeEntryMapBackEdge();
851 void SExprBuilder::enterCFGBlockBody(const CFGBlock *B) {
852 // The merge*() methods have created arguments.
853 // Push those arguments onto the basic block.
854 CurrentBB->arguments().reserve(
855 static_cast<unsigned>(CurrentArguments.size()), Arena);
856 for (auto *A : CurrentArguments)
857 CurrentBB->addArgument(A);
860 void SExprBuilder::handleStatement(const Stmt *S) {
861 til::SExpr *E = translate(S, nullptr);
865 void SExprBuilder::handleDestructorCall(const VarDecl *VD,
866 const CXXDestructorDecl *DD) {
867 til::SExpr *Sf = new (Arena) til::LiteralPtr(VD);
868 til::SExpr *Dr = new (Arena) til::LiteralPtr(DD);
869 til::SExpr *Ap = new (Arena) til::Apply(Dr, Sf);
870 til::SExpr *E = new (Arena) til::Call(Ap);
871 addStatement(E, nullptr);
874 void SExprBuilder::exitCFGBlockBody(const CFGBlock *B) {
875 CurrentBB->instructions().reserve(
876 static_cast<unsigned>(CurrentInstructions.size()), Arena);
877 for (auto *V : CurrentInstructions)
878 CurrentBB->addInstruction(V);
880 // Create an appropriate terminator
881 unsigned N = B->succ_size();
882 auto It = B->succ_begin();
884 til::BasicBlock *BB = *It ? lookupBlock(*It) : nullptr;
886 unsigned Idx = BB ? BB->findPredecessorIndex(CurrentBB) : 0;
887 auto *Tm = new (Arena) til::Goto(BB, Idx);
888 CurrentBB->setTerminator(Tm);
891 til::SExpr *C = translate(B->getTerminatorCondition(true), nullptr);
892 til::BasicBlock *BB1 = *It ? lookupBlock(*It) : nullptr;
894 til::BasicBlock *BB2 = *It ? lookupBlock(*It) : nullptr;
895 // FIXME: make sure these aren't critical edges.
896 auto *Tm = new (Arena) til::Branch(C, BB1, BB2);
897 CurrentBB->setTerminator(Tm);
901 void SExprBuilder::handleSuccessor(const CFGBlock *Succ) {
902 ++CurrentBlockInfo->UnprocessedSuccessors;
905 void SExprBuilder::handleSuccessorBackEdge(const CFGBlock *Succ) {
906 mergePhiNodesBackEdge(Succ);
907 ++BBInfo[Succ->getBlockID()].ProcessedPredecessors;
910 void SExprBuilder::exitCFGBlock(const CFGBlock *B) {
911 CurrentArguments.clear();
912 CurrentInstructions.clear();
913 CurrentBlockInfo->ExitMap = std::move(CurrentLVarMap);
915 CurrentBlockInfo = nullptr;
918 void SExprBuilder::exitCFG(const CFGBlock *Last) {
919 for (auto *Ph : IncompleteArgs) {
920 if (Ph->status() == til::Phi::PH_Incomplete)
921 simplifyIncompleteArg(Ph);
924 CurrentArguments.clear();
925 CurrentInstructions.clear();
926 IncompleteArgs.clear();
930 void printSCFG(CFGWalker &Walker) {
931 llvm::BumpPtrAllocator Bpa;
932 til::MemRegionRef Arena(&Bpa);
933 SExprBuilder SxBuilder(Arena);
934 til::SCFG *Scfg = SxBuilder.buildCFG(Walker);
935 TILPrinter::print(Scfg, llvm::errs());