1//===- ThreadSafetyCommon.cpp ---------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Implementation of the interfaces declared in ThreadSafetyCommon.h
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/Analysis/Analyses/ThreadSafetyCommon.h"
14#include "clang/AST/Attr.h"
15#include "clang/AST/Decl.h"
16#include "clang/AST/DeclCXX.h"
17#include "clang/AST/DeclGroup.h"
18#include "clang/AST/DeclObjC.h"
19#include "clang/AST/Expr.h"
20#include "clang/AST/ExprCXX.h"
21#include "clang/AST/OperationKinds.h"
22#include "clang/AST/Stmt.h"
23#include "clang/AST/Type.h"
24#include "clang/Analysis/Analyses/ThreadSafetyTIL.h"
25#include "clang/Analysis/CFG.h"
26#include "clang/Basic/LLVM.h"
27#include "clang/Basic/OperatorKinds.h"
28#include "clang/Basic/Specifiers.h"
29#include "llvm/ADT/StringExtras.h"
30#include "llvm/ADT/StringRef.h"
31#include <algorithm>
32#include <cassert>
33#include <string>
34#include <utility>
35
36using namespace clang;
37using namespace threadSafety;
38
39// From ThreadSafetyUtil.h
40std::string threadSafety::getSourceLiteralString(const Expr *CE) {
41 switch (CE->getStmtClass()) {
42 case Stmt::IntegerLiteralClass:
43 return toString(cast<IntegerLiteral>(Val: CE)->getValue(), 10, true);
44 case Stmt::StringLiteralClass: {
45 std::string ret("\"");
46 ret += cast<StringLiteral>(Val: CE)->getString();
47 ret += "\"";
48 return ret;
49 }
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:
57 default:
58 return "#lit";
59 }
60}
61
62// Return true if E is a variable that points to an incomplete Phi node.
63static bool isIncompletePhi(const til::SExpr *E) {
64 if (const auto *Ph = dyn_cast<til::Phi>(Val: E))
65 return Ph->status() == til::Phi::PH_Incomplete;
66 return false;
67}
68
69static constexpr std::pair<StringRef, bool> ClassifyCapabilityFallback{
70 /*Kind=*/StringRef("mutex"),
71 /*Reentrant=*/false};
72
73// Returns pair (Kind, Reentrant).
74static std::pair<StringRef, bool> classifyCapability(const TypeDecl &TD) {
75 if (const auto *CA = TD.getAttr<CapabilityAttr>())
76 return {CA->getName(), TD.hasAttr<ReentrantCapabilityAttr>()};
77
78 return ClassifyCapabilityFallback;
79}
80
81// Returns pair (Kind, Reentrant).
82static std::pair<StringRef, bool> classifyCapability(QualType QT) {
83 // We need to look at the declaration of the type of the value to determine
84 // which it is. The type should either be a record or a typedef, or a pointer
85 // or reference thereof.
86 if (const auto *RT = QT->getAs<RecordType>()) {
87 if (const auto *RD = RT->getDecl())
88 return classifyCapability(*RD);
89 } else if (const auto *TT = QT->getAs<TypedefType>()) {
90 if (const auto *TD = TT->getDecl())
91 return classifyCapability(*TD);
92 } else if (QT->isPointerOrReferenceType())
93 return classifyCapability(QT: QT->getPointeeType());
94
95 return ClassifyCapabilityFallback;
96}
97
98CapabilityExpr::CapabilityExpr(const til::SExpr *E, QualType QT, bool Neg) {
99 const auto &[Kind, Reentrant] = classifyCapability(QT);
100 *this = CapabilityExpr(E, Kind, Neg, Reentrant);
101}
102
103using CallingContext = SExprBuilder::CallingContext;
104
105til::SExpr *SExprBuilder::lookupStmt(const Stmt *S) { return SMap.lookup(Val: S); }
106
107til::SCFG *SExprBuilder::buildCFG(CFGWalker &Walker) {
108 Walker.walk(V&: *this);
109 return Scfg;
110}
111
112static bool isCalleeArrow(const Expr *E) {
113 const auto *ME = dyn_cast<MemberExpr>(Val: E->IgnoreParenCasts());
114 return ME ? ME->isArrow() : false;
115}
116
117/// Translate a clang expression in an attribute to a til::SExpr.
118/// Constructs the context from D, DeclExp, and SelfDecl.
119///
120/// \param AttrExp The expression to translate.
121/// \param D The declaration to which the attribute is attached.
122/// \param DeclExp An expression involving the Decl to which the attribute
123/// is attached. E.g. the call to a function.
124/// \param Self S-expression to substitute for a \ref CXXThisExpr in a call,
125/// or argument to a cleanup function.
126CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
127 const NamedDecl *D,
128 const Expr *DeclExp,
129 til::SExpr *Self) {
130 // If we are processing a raw attribute expression, with no substitutions.
131 if (!DeclExp && !Self)
132 return translateAttrExpr(AttrExp, Ctx: nullptr);
133
134 CallingContext Ctx(nullptr, D);
135
136 // Examine DeclExp to find SelfArg and FunArgs, which are used to substitute
137 // for formal parameters when we call buildMutexID later.
138 if (!DeclExp)
139 /* We'll use Self. */;
140 else if (const auto *ME = dyn_cast<MemberExpr>(Val: DeclExp)) {
141 Ctx.SelfArg = ME->getBase();
142 Ctx.SelfArrow = ME->isArrow();
143 } else if (const auto *CE = dyn_cast<CXXMemberCallExpr>(Val: DeclExp)) {
144 Ctx.SelfArg = CE->getImplicitObjectArgument();
145 Ctx.SelfArrow = isCalleeArrow(CE->getCallee());
146 Ctx.NumArgs = CE->getNumArgs();
147 Ctx.FunArgs = CE->getArgs();
148 } else if (const auto *CE = dyn_cast<CallExpr>(Val: DeclExp)) {
149 // Calls to operators that are members need to be treated like member calls.
150 if (isa<CXXOperatorCallExpr>(Val: CE) && isa<CXXMethodDecl>(Val: D)) {
151 Ctx.SelfArg = CE->getArg(Arg: 0);
152 Ctx.SelfArrow = false;
153 Ctx.NumArgs = CE->getNumArgs() - 1;
154 Ctx.FunArgs = CE->getArgs() + 1;
155 } else {
156 Ctx.NumArgs = CE->getNumArgs();
157 Ctx.FunArgs = CE->getArgs();
158 }
159 } else if (const auto *CE = dyn_cast<CXXConstructExpr>(Val: DeclExp)) {
160 Ctx.SelfArg = nullptr; // Will be set below
161 Ctx.NumArgs = CE->getNumArgs();
162 Ctx.FunArgs = CE->getArgs();
163 }
164
165 // Usually we want to substitute the self-argument for "this", but lambdas
166 // are an exception: "this" on or in a lambda call operator doesn't refer
167 // to the lambda, but to captured "this" in the context it was created in.
168 // This can happen for operator calls and member calls, so fix it up here.
169 if (const auto *CMD = dyn_cast<CXXMethodDecl>(Val: D))
170 if (CMD->getParent()->isLambda())
171 Ctx.SelfArg = nullptr;
172
173 if (Self) {
174 assert(!Ctx.SelfArg && "Ambiguous self argument");
175 assert(isa<FunctionDecl>(D) && "Self argument requires function");
176 if (isa<CXXMethodDecl>(Val: D))
177 Ctx.SelfArg = Self;
178 else
179 Ctx.FunArgs = Self;
180
181 // If the attribute has no arguments, then assume the argument is "this".
182 if (!AttrExp)
183 return CapabilityExpr(
184 Self, cast<CXXMethodDecl>(Val: D)->getFunctionObjectParameterType(),
185 false);
186 else // For most attributes.
187 return translateAttrExpr(AttrExp, Ctx: &Ctx);
188 }
189
190 // If the attribute has no arguments, then assume the argument is "this".
191 if (!AttrExp)
192 return translateAttrExpr(AttrExp: cast<const Expr *>(Val&: Ctx.SelfArg), Ctx: nullptr);
193 else // For most attributes.
194 return translateAttrExpr(AttrExp, Ctx: &Ctx);
195}
196
197/// Translate a clang expression in an attribute to a til::SExpr.
198// This assumes a CallingContext has already been created.
199CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
200 CallingContext *Ctx) {
201 if (!AttrExp)
202 return CapabilityExpr();
203
204 if (const auto* SLit = dyn_cast<StringLiteral>(Val: AttrExp)) {
205 if (SLit->getString() == "*")
206 // The "*" expr is a universal lock, which essentially turns off
207 // checks until it is removed from the lockset.
208 return CapabilityExpr(new (Arena) til::Wildcard(), StringRef("wildcard"),
209 /*Neg=*/false, /*Reentrant=*/false);
210 else
211 // Ignore other string literals for now.
212 return CapabilityExpr();
213 }
214
215 bool Neg = false;
216 if (const auto *OE = dyn_cast<CXXOperatorCallExpr>(Val: AttrExp)) {
217 if (OE->getOperator() == OO_Exclaim) {
218 Neg = true;
219 AttrExp = OE->getArg(0);
220 }
221 }
222 else if (const auto *UO = dyn_cast<UnaryOperator>(Val: AttrExp)) {
223 if (UO->getOpcode() == UO_LNot) {
224 Neg = true;
225 AttrExp = UO->getSubExpr()->IgnoreImplicit();
226 }
227 }
228
229 const til::SExpr *E = translate(AttrExp, Ctx);
230
231 // Trap mutex expressions like nullptr, or 0.
232 // Any literal value is nonsense.
233 if (!E || isa<til::Literal>(Val: E))
234 return CapabilityExpr();
235
236 // Hack to deal with smart pointers -- strip off top-level pointer casts.
237 if (const auto *CE = dyn_cast<til::Cast>(E)) {
238 if (CE->castOpcode() == til::CAST_objToPtr)
239 E = CE->expr();
240 }
241 return CapabilityExpr(E, AttrExp->getType(), Neg);
242}
243
244til::LiteralPtr *SExprBuilder::createVariable(const VarDecl *VD) {
245 return new (Arena) til::LiteralPtr(VD);
246}
247
248// Translate a clang statement or expression to a TIL expression.
249// Also performs substitution of variables; Ctx provides the context.
250// Dispatches on the type of S.
251til::SExpr *SExprBuilder::translate(const Stmt *S, CallingContext *Ctx) {
252 if (!S)
253 return nullptr;
254
255 // Check if S has already been translated and cached.
256 // This handles the lookup of SSA names for DeclRefExprs here.
257 if (til::SExpr *E = lookupStmt(S))
258 return E;
259
260 switch (S->getStmtClass()) {
261 case Stmt::DeclRefExprClass:
262 return translateDeclRefExpr(DRE: cast<DeclRefExpr>(Val: S), Ctx);
263 case Stmt::CXXThisExprClass:
264 return translateCXXThisExpr(TE: cast<CXXThisExpr>(Val: S), Ctx);
265 case Stmt::MemberExprClass:
266 return translateMemberExpr(ME: cast<MemberExpr>(Val: S), Ctx);
267 case Stmt::ObjCIvarRefExprClass:
268 return translateObjCIVarRefExpr(IVRE: cast<ObjCIvarRefExpr>(Val: S), Ctx);
269 case Stmt::CallExprClass:
270 return translateCallExpr(CE: cast<CallExpr>(Val: S), Ctx);
271 case Stmt::CXXMemberCallExprClass:
272 return translateCXXMemberCallExpr(ME: cast<CXXMemberCallExpr>(Val: S), Ctx);
273 case Stmt::CXXOperatorCallExprClass:
274 return translateCXXOperatorCallExpr(OCE: cast<CXXOperatorCallExpr>(Val: S), Ctx);
275 case Stmt::UnaryOperatorClass:
276 return translateUnaryOperator(UO: cast<UnaryOperator>(Val: S), Ctx);
277 case Stmt::BinaryOperatorClass:
278 case Stmt::CompoundAssignOperatorClass:
279 return translateBinaryOperator(BO: cast<BinaryOperator>(Val: S), Ctx);
280
281 case Stmt::ArraySubscriptExprClass:
282 return translateArraySubscriptExpr(E: cast<ArraySubscriptExpr>(Val: S), Ctx);
283 case Stmt::ConditionalOperatorClass:
284 return translateAbstractConditionalOperator(
285 cast<ConditionalOperator>(Val: S), Ctx);
286 case Stmt::BinaryConditionalOperatorClass:
287 return translateAbstractConditionalOperator(
288 cast<BinaryConditionalOperator>(Val: S), Ctx);
289
290 // We treat these as no-ops
291 case Stmt::ConstantExprClass:
292 return translate(S: cast<ConstantExpr>(Val: S)->getSubExpr(), Ctx);
293 case Stmt::ParenExprClass:
294 return translate(cast<ParenExpr>(Val: S)->getSubExpr(), Ctx);
295 case Stmt::ExprWithCleanupsClass:
296 return translate(S: cast<ExprWithCleanups>(Val: S)->getSubExpr(), Ctx);
297 case Stmt::CXXBindTemporaryExprClass:
298 return translate(cast<CXXBindTemporaryExpr>(Val: S)->getSubExpr(), Ctx);
299 case Stmt::MaterializeTemporaryExprClass:
300 return translate(cast<MaterializeTemporaryExpr>(Val: S)->getSubExpr(), Ctx);
301
302 // Collect all literals
303 case Stmt::CharacterLiteralClass:
304 case Stmt::CXXNullPtrLiteralExprClass:
305 case Stmt::GNUNullExprClass:
306 case Stmt::CXXBoolLiteralExprClass:
307 case Stmt::FloatingLiteralClass:
308 case Stmt::ImaginaryLiteralClass:
309 case Stmt::IntegerLiteralClass:
310 case Stmt::StringLiteralClass:
311 case Stmt::ObjCStringLiteralClass:
312 return new (Arena) til::Literal(cast<Expr>(Val: S));
313
314 case Stmt::DeclStmtClass:
315 return translateDeclStmt(S: cast<DeclStmt>(Val: S), Ctx);
316 default:
317 break;
318 }
319 if (const auto *CE = dyn_cast<CastExpr>(Val: S))
320 return translateCastExpr(CE, Ctx);
321
322 return new (Arena) til::Undefined(S);
323}
324
325til::SExpr *SExprBuilder::translateDeclRefExpr(const DeclRefExpr *DRE,
326 CallingContext *Ctx) {
327 const auto *VD = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
328
329 // Function parameters require substitution and/or renaming.
330 if (const auto *PV = dyn_cast<ParmVarDecl>(VD)) {
331 unsigned I = PV->getFunctionScopeIndex();
332 const DeclContext *D = PV->getDeclContext();
333 if (Ctx && Ctx->FunArgs) {
334 const Decl *Canonical = Ctx->AttrDecl->getCanonicalDecl();
335 if (isa<FunctionDecl>(Val: D)
336 ? (cast<FunctionDecl>(Val: D)->getCanonicalDecl() == Canonical)
337 : (cast<ObjCMethodDecl>(Val: D)->getCanonicalDecl() == Canonical)) {
338 // Substitute call arguments for references to function parameters
339 if (const Expr *const *FunArgs =
340 dyn_cast<const Expr *const *>(Val&: Ctx->FunArgs)) {
341 assert(I < Ctx->NumArgs);
342 return translate(FunArgs[I], Ctx->Prev);
343 }
344
345 assert(I == 0);
346 return cast<til::SExpr *>(Val&: Ctx->FunArgs);
347 }
348 }
349 // Map the param back to the param of the original function declaration
350 // for consistent comparisons.
351 VD = isa<FunctionDecl>(Val: D)
352 ? cast<FunctionDecl>(Val: D)->getCanonicalDecl()->getParamDecl(i: I)
353 : cast<ObjCMethodDecl>(Val: D)->getCanonicalDecl()->getParamDecl(Idx: I);
354 }
355
356 // For non-local variables, treat it as a reference to a named object.
357 return new (Arena) til::LiteralPtr(VD);
358}
359
360til::SExpr *SExprBuilder::translateCXXThisExpr(const CXXThisExpr *TE,
361 CallingContext *Ctx) {
362 // Substitute for 'this'
363 if (Ctx && Ctx->SelfArg) {
364 if (const auto *SelfArg = dyn_cast<const Expr *>(Val&: Ctx->SelfArg))
365 return translate(SelfArg, Ctx->Prev);
366 else
367 return cast<til::SExpr *>(Val&: Ctx->SelfArg);
368 }
369 assert(SelfVar && "We have no variable for 'this'!");
370 return SelfVar;
371}
372
373static const ValueDecl *getValueDeclFromSExpr(const til::SExpr *E) {
374 if (const auto *V = dyn_cast<til::Variable>(Val: E))
375 return V->clangDecl();
376 if (const auto *Ph = dyn_cast<til::Phi>(Val: E))
377 return Ph->clangDecl();
378 if (const auto *P = dyn_cast<til::Project>(Val: E))
379 return P->clangDecl();
380 if (const auto *L = dyn_cast<til::LiteralPtr>(Val: E))
381 return L->clangDecl();
382 return nullptr;
383}
384
385static bool hasAnyPointerType(const til::SExpr *E) {
386 auto *VD = getValueDeclFromSExpr(E);
387 if (VD && VD->getType()->isAnyPointerType())
388 return true;
389 if (const auto *C = dyn_cast<til::Cast>(Val: E))
390 return C->castOpcode() == til::CAST_objToPtr;
391
392 return false;
393}
394
395// Grab the very first declaration of virtual method D
396static const CXXMethodDecl *getFirstVirtualDecl(const CXXMethodDecl *D) {
397 while (true) {
398 D = D->getCanonicalDecl();
399 auto OverriddenMethods = D->overridden_methods();
400 if (OverriddenMethods.begin() == OverriddenMethods.end())
401 return D; // Method does not override anything
402 // FIXME: this does not work with multiple inheritance.
403 D = *OverriddenMethods.begin();
404 }
405 return nullptr;
406}
407
408til::SExpr *SExprBuilder::translateMemberExpr(const MemberExpr *ME,
409 CallingContext *Ctx) {
410 til::SExpr *BE = translate(ME->getBase(), Ctx);
411 til::SExpr *E = new (Arena) til::SApply(BE);
412
413 const auto *D = cast<ValueDecl>(ME->getMemberDecl()->getCanonicalDecl());
414 if (const auto *VD = dyn_cast<CXXMethodDecl>(D))
415 D = getFirstVirtualDecl(VD);
416
417 til::Project *P = new (Arena) til::Project(E, D);
418 if (hasAnyPointerType(E: BE))
419 P->setArrow(true);
420 return P;
421}
422
423til::SExpr *SExprBuilder::translateObjCIVarRefExpr(const ObjCIvarRefExpr *IVRE,
424 CallingContext *Ctx) {
425 til::SExpr *BE = translate(IVRE->getBase(), Ctx);
426 til::SExpr *E = new (Arena) til::SApply(BE);
427
428 const auto *D = cast<ObjCIvarDecl>(Val: IVRE->getDecl()->getCanonicalDecl());
429
430 til::Project *P = new (Arena) til::Project(E, D);
431 if (hasAnyPointerType(E: BE))
432 P->setArrow(true);
433 return P;
434}
435
436til::SExpr *SExprBuilder::translateCallExpr(const CallExpr *CE,
437 CallingContext *Ctx,
438 const Expr *SelfE) {
439 if (CapabilityExprMode) {
440 // Handle LOCK_RETURNED
441 if (const FunctionDecl *FD = CE->getDirectCallee()) {
442 FD = FD->getMostRecentDecl();
443 if (LockReturnedAttr *At = FD->getAttr<LockReturnedAttr>()) {
444 CallingContext LRCallCtx(Ctx);
445 LRCallCtx.AttrDecl = CE->getDirectCallee();
446 LRCallCtx.SelfArg = SelfE;
447 LRCallCtx.NumArgs = CE->getNumArgs();
448 LRCallCtx.FunArgs = CE->getArgs();
449 return const_cast<til::SExpr *>(
450 translateAttrExpr(At->getArg(), &LRCallCtx).sexpr());
451 }
452 }
453 }
454
455 til::SExpr *E = translate(CE->getCallee(), Ctx);
456 for (const auto *Arg : CE->arguments()) {
457 til::SExpr *A = translate(S: Arg, Ctx);
458 E = new (Arena) til::Apply(E, A);
459 }
460 return new (Arena) til::Call(E, CE);
461}
462
463til::SExpr *SExprBuilder::translateCXXMemberCallExpr(
464 const CXXMemberCallExpr *ME, CallingContext *Ctx) {
465 if (CapabilityExprMode) {
466 // Ignore calls to get() on smart pointers.
467 if (ME->getMethodDecl()->getNameAsString() == "get" &&
468 ME->getNumArgs() == 0) {
469 auto *E = translate(ME->getImplicitObjectArgument(), Ctx);
470 return new (Arena) til::Cast(til::CAST_objToPtr, E);
471 // return E;
472 }
473 }
474 return translateCallExpr(CE: cast<CallExpr>(Val: ME), Ctx,
475 SelfE: ME->getImplicitObjectArgument());
476}
477
478til::SExpr *SExprBuilder::translateCXXOperatorCallExpr(
479 const CXXOperatorCallExpr *OCE, CallingContext *Ctx) {
480 if (CapabilityExprMode) {
481 // Ignore operator * and operator -> on smart pointers.
482 OverloadedOperatorKind k = OCE->getOperator();
483 if (k == OO_Star || k == OO_Arrow) {
484 auto *E = translate(S: OCE->getArg(0), Ctx);
485 return new (Arena) til::Cast(til::CAST_objToPtr, E);
486 // return E;
487 }
488 }
489 return translateCallExpr(CE: cast<CallExpr>(Val: OCE), Ctx);
490}
491
492til::SExpr *SExprBuilder::translateUnaryOperator(const UnaryOperator *UO,
493 CallingContext *Ctx) {
494 switch (UO->getOpcode()) {
495 case UO_PostInc:
496 case UO_PostDec:
497 case UO_PreInc:
498 case UO_PreDec:
499 return new (Arena) til::Undefined(UO);
500
501 case UO_AddrOf:
502 if (CapabilityExprMode) {
503 // interpret &Graph::mu_ as an existential.
504 if (const auto *DRE = dyn_cast<DeclRefExpr>(Val: UO->getSubExpr())) {
505 if (DRE->getDecl()->isCXXInstanceMember()) {
506 // This is a pointer-to-member expression, e.g. &MyClass::mu_.
507 // We interpret this syntax specially, as a wildcard.
508 auto *W = new (Arena) til::Wildcard();
509 return new (Arena) til::Project(W, DRE->getDecl());
510 }
511 }
512 }
513 // otherwise, & is a no-op
514 return translate(UO->getSubExpr(), Ctx);
515
516 // We treat these as no-ops
517 case UO_Deref:
518 case UO_Plus:
519 return translate(UO->getSubExpr(), Ctx);
520
521 case UO_Minus:
522 return new (Arena)
523 til::UnaryOp(til::UOP_Minus, translate(UO->getSubExpr(), Ctx));
524 case UO_Not:
525 return new (Arena)
526 til::UnaryOp(til::UOP_BitNot, translate(UO->getSubExpr(), Ctx));
527 case UO_LNot:
528 return new (Arena)
529 til::UnaryOp(til::UOP_LogicNot, translate(UO->getSubExpr(), Ctx));
530
531 // Currently unsupported
532 case UO_Real:
533 case UO_Imag:
534 case UO_Extension:
535 case UO_Coawait:
536 return new (Arena) til::Undefined(UO);
537 }
538 return new (Arena) til::Undefined(UO);
539}
540
541til::SExpr *SExprBuilder::translateBinOp(til::TIL_BinaryOpcode Op,
542 const BinaryOperator *BO,
543 CallingContext *Ctx, bool Reverse) {
544 til::SExpr *E0 = translate(BO->getLHS(), Ctx);
545 til::SExpr *E1 = translate(BO->getRHS(), Ctx);
546 if (Reverse)
547 return new (Arena) til::BinaryOp(Op, E1, E0);
548 else
549 return new (Arena) til::BinaryOp(Op, E0, E1);
550}
551
552til::SExpr *SExprBuilder::translateBinAssign(til::TIL_BinaryOpcode Op,
553 const BinaryOperator *BO,
554 CallingContext *Ctx,
555 bool Assign) {
556 const Expr *LHS = BO->getLHS();
557 const Expr *RHS = BO->getRHS();
558 til::SExpr *E0 = translate(LHS, Ctx);
559 til::SExpr *E1 = translate(RHS, Ctx);
560
561 const ValueDecl *VD = nullptr;
562 til::SExpr *CV = nullptr;
563 if (const auto *DRE = dyn_cast<DeclRefExpr>(Val: LHS)) {
564 VD = DRE->getDecl();
565 CV = lookupVarDecl(VD);
566 }
567
568 if (!Assign) {
569 til::SExpr *Arg = CV ? CV : new (Arena) til::Load(E0);
570 E1 = new (Arena) til::BinaryOp(Op, Arg, E1);
571 E1 = addStatement(E: E1, S: nullptr, VD);
572 }
573 if (VD && CV)
574 return updateVarDecl(VD, E: E1);
575 return new (Arena) til::Store(E0, E1);
576}
577
578til::SExpr *SExprBuilder::translateBinaryOperator(const BinaryOperator *BO,
579 CallingContext *Ctx) {
580 switch (BO->getOpcode()) {
581 case BO_PtrMemD:
582 case BO_PtrMemI:
583 return new (Arena) til::Undefined(BO);
584
585 case BO_Mul: return translateBinOp(Op: til::BOP_Mul, BO, Ctx);
586 case BO_Div: return translateBinOp(Op: til::BOP_Div, BO, Ctx);
587 case BO_Rem: return translateBinOp(Op: til::BOP_Rem, BO, Ctx);
588 case BO_Add: return translateBinOp(Op: til::BOP_Add, BO, Ctx);
589 case BO_Sub: return translateBinOp(Op: til::BOP_Sub, BO, Ctx);
590 case BO_Shl: return translateBinOp(Op: til::BOP_Shl, BO, Ctx);
591 case BO_Shr: return translateBinOp(Op: til::BOP_Shr, BO, Ctx);
592 case BO_LT: return translateBinOp(Op: til::BOP_Lt, BO, Ctx);
593 case BO_GT: return translateBinOp(Op: til::BOP_Lt, BO, Ctx, Reverse: true);
594 case BO_LE: return translateBinOp(Op: til::BOP_Leq, BO, Ctx);
595 case BO_GE: return translateBinOp(Op: til::BOP_Leq, BO, Ctx, Reverse: true);
596 case BO_EQ: return translateBinOp(Op: til::BOP_Eq, BO, Ctx);
597 case BO_NE: return translateBinOp(Op: til::BOP_Neq, BO, Ctx);
598 case BO_Cmp: return translateBinOp(Op: til::BOP_Cmp, BO, Ctx);
599 case BO_And: return translateBinOp(Op: til::BOP_BitAnd, BO, Ctx);
600 case BO_Xor: return translateBinOp(Op: til::BOP_BitXor, BO, Ctx);
601 case BO_Or: return translateBinOp(Op: til::BOP_BitOr, BO, Ctx);
602 case BO_LAnd: return translateBinOp(Op: til::BOP_LogicAnd, BO, Ctx);
603 case BO_LOr: return translateBinOp(Op: til::BOP_LogicOr, BO, Ctx);
604
605 case BO_Assign: return translateBinAssign(Op: til::BOP_Eq, BO, Ctx, Assign: true);
606 case BO_MulAssign: return translateBinAssign(Op: til::BOP_Mul, BO, Ctx);
607 case BO_DivAssign: return translateBinAssign(Op: til::BOP_Div, BO, Ctx);
608 case BO_RemAssign: return translateBinAssign(Op: til::BOP_Rem, BO, Ctx);
609 case BO_AddAssign: return translateBinAssign(Op: til::BOP_Add, BO, Ctx);
610 case BO_SubAssign: return translateBinAssign(Op: til::BOP_Sub, BO, Ctx);
611 case BO_ShlAssign: return translateBinAssign(Op: til::BOP_Shl, BO, Ctx);
612 case BO_ShrAssign: return translateBinAssign(Op: til::BOP_Shr, BO, Ctx);
613 case BO_AndAssign: return translateBinAssign(Op: til::BOP_BitAnd, BO, Ctx);
614 case BO_XorAssign: return translateBinAssign(Op: til::BOP_BitXor, BO, Ctx);
615 case BO_OrAssign: return translateBinAssign(Op: til::BOP_BitOr, BO, Ctx);
616
617 case BO_Comma:
618 // The clang CFG should have already processed both sides.
619 return translate(BO->getRHS(), Ctx);
620 }
621 return new (Arena) til::Undefined(BO);
622}
623
624til::SExpr *SExprBuilder::translateCastExpr(const CastExpr *CE,
625 CallingContext *Ctx) {
626 CastKind K = CE->getCastKind();
627 switch (K) {
628 case CK_LValueToRValue: {
629 if (const auto *DRE = dyn_cast<DeclRefExpr>(Val: CE->getSubExpr())) {
630 til::SExpr *E0 = lookupVarDecl(VD: DRE->getDecl());
631 if (E0)
632 return E0;
633 }
634 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
635 return E0;
636 // FIXME!! -- get Load working properly
637 // return new (Arena) til::Load(E0);
638 }
639 case CK_NoOp:
640 case CK_DerivedToBase:
641 case CK_UncheckedDerivedToBase:
642 case CK_ArrayToPointerDecay:
643 case CK_FunctionToPointerDecay: {
644 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
645 return E0;
646 }
647 default: {
648 // FIXME: handle different kinds of casts.
649 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
650 if (CapabilityExprMode)
651 return E0;
652 return new (Arena) til::Cast(til::CAST_none, E0);
653 }
654 }
655}
656
657til::SExpr *
658SExprBuilder::translateArraySubscriptExpr(const ArraySubscriptExpr *E,
659 CallingContext *Ctx) {
660 til::SExpr *E0 = translate(E->getBase(), Ctx);
661 til::SExpr *E1 = translate(E->getIdx(), Ctx);
662 return new (Arena) til::ArrayIndex(E0, E1);
663}
664
665til::SExpr *
666SExprBuilder::translateAbstractConditionalOperator(
667 const AbstractConditionalOperator *CO, CallingContext *Ctx) {
668 auto *C = translate(CO->getCond(), Ctx);
669 auto *T = translate(CO->getTrueExpr(), Ctx);
670 auto *E = translate(CO->getFalseExpr(), Ctx);
671 return new (Arena) til::IfThenElse(C, T, E);
672}
673
674til::SExpr *
675SExprBuilder::translateDeclStmt(const DeclStmt *S, CallingContext *Ctx) {
676 DeclGroupRef DGrp = S->getDeclGroup();
677 for (auto *I : DGrp) {
678 if (auto *VD = dyn_cast_or_null<VarDecl>(Val: I)) {
679 Expr *E = VD->getInit();
680 til::SExpr* SE = translate(E, Ctx);
681
682 // Add local variables with trivial type to the variable map
683 QualType T = VD->getType();
684 if (T.isTrivialType(Context: VD->getASTContext()))
685 return addVarDecl(VD, SE);
686 else {
687 // TODO: add alloca
688 }
689 }
690 }
691 return nullptr;
692}
693
694// If (E) is non-trivial, then add it to the current basic block, and
695// update the statement map so that S refers to E. Returns a new variable
696// that refers to E.
697// If E is trivial returns E.
698til::SExpr *SExprBuilder::addStatement(til::SExpr* E, const Stmt *S,
699 const ValueDecl *VD) {
700 if (!E || !CurrentBB || E->block() || til::ThreadSafetyTIL::isTrivial(E))
701 return E;
702 if (VD)
703 E = new (Arena) til::Variable(E, VD);
704 CurrentInstructions.push_back(x: E);
705 if (S)
706 insertStmt(S, E);
707 return E;
708}
709
710// Returns the current value of VD, if known, and nullptr otherwise.
711til::SExpr *SExprBuilder::lookupVarDecl(const ValueDecl *VD) {
712 auto It = LVarIdxMap.find(Val: VD);
713 if (It != LVarIdxMap.end()) {
714 assert(CurrentLVarMap[It->second].first == VD);
715 return CurrentLVarMap[It->second].second;
716 }
717 return nullptr;
718}
719
720// if E is a til::Variable, update its clangDecl.
721static void maybeUpdateVD(til::SExpr *E, const ValueDecl *VD) {
722 if (!E)
723 return;
724 if (auto *V = dyn_cast<til::Variable>(Val: E)) {
725 if (!V->clangDecl())
726 V->setClangDecl(VD);
727 }
728}
729
730// Adds a new variable declaration.
731til::SExpr *SExprBuilder::addVarDecl(const ValueDecl *VD, til::SExpr *E) {
732 maybeUpdateVD(E, VD);
733 LVarIdxMap.insert(KV: std::make_pair(x&: VD, y: CurrentLVarMap.size()));
734 CurrentLVarMap.makeWritable();
735 CurrentLVarMap.push_back(Elem: std::make_pair(x&: VD, y&: E));
736 return E;
737}
738
739// Updates a current variable declaration. (E.g. by assignment)
740til::SExpr *SExprBuilder::updateVarDecl(const ValueDecl *VD, til::SExpr *E) {
741 maybeUpdateVD(E, VD);
742 auto It = LVarIdxMap.find(Val: VD);
743 if (It == LVarIdxMap.end()) {
744 til::SExpr *Ptr = new (Arena) til::LiteralPtr(VD);
745 til::SExpr *St = new (Arena) til::Store(Ptr, E);
746 return St;
747 }
748 CurrentLVarMap.makeWritable();
749 CurrentLVarMap.elem(i: It->second).second = E;
750 return E;
751}
752
753// Make a Phi node in the current block for the i^th variable in CurrentVarMap.
754// If E != null, sets Phi[CurrentBlockInfo->ArgIndex] = E.
755// If E == null, this is a backedge and will be set later.
756void SExprBuilder::makePhiNodeVar(unsigned i, unsigned NPreds, til::SExpr *E) {
757 unsigned ArgIndex = CurrentBlockInfo->ProcessedPredecessors;
758 assert(ArgIndex > 0 && ArgIndex < NPreds);
759
760 til::SExpr *CurrE = CurrentLVarMap[i].second;
761 if (CurrE->block() == CurrentBB) {
762 // We already have a Phi node in the current block,
763 // so just add the new variable to the Phi node.
764 auto *Ph = dyn_cast<til::Phi>(Val: CurrE);
765 assert(Ph && "Expecting Phi node.");
766 if (E)
767 Ph->values()[ArgIndex] = E;
768 return;
769 }
770
771 // Make a new phi node: phi(..., E)
772 // All phi args up to the current index are set to the current value.
773 til::Phi *Ph = new (Arena) til::Phi(Arena, NPreds);
774 Ph->values().setValues(Sz: NPreds, C: nullptr);
775 for (unsigned PIdx = 0; PIdx < ArgIndex; ++PIdx)
776 Ph->values()[PIdx] = CurrE;
777 if (E)
778 Ph->values()[ArgIndex] = E;
779 Ph->setClangDecl(CurrentLVarMap[i].first);
780 // If E is from a back-edge, or either E or CurrE are incomplete, then
781 // mark this node as incomplete; we may need to remove it later.
782 if (!E || isIncompletePhi(E) || isIncompletePhi(E: CurrE))
783 Ph->setStatus(til::Phi::PH_Incomplete);
784
785 // Add Phi node to current block, and update CurrentLVarMap[i]
786 CurrentArguments.push_back(x: Ph);
787 if (Ph->status() == til::Phi::PH_Incomplete)
788 IncompleteArgs.push_back(x: Ph);
789
790 CurrentLVarMap.makeWritable();
791 CurrentLVarMap.elem(i).second = Ph;
792}
793
794// Merge values from Map into the current variable map.
795// This will construct Phi nodes in the current basic block as necessary.
796void SExprBuilder::mergeEntryMap(LVarDefinitionMap Map) {
797 assert(CurrentBlockInfo && "Not processing a block!");
798
799 if (!CurrentLVarMap.valid()) {
800 // Steal Map, using copy-on-write.
801 CurrentLVarMap = std::move(Map);
802 return;
803 }
804 if (CurrentLVarMap.sameAs(V: Map))
805 return; // Easy merge: maps from different predecessors are unchanged.
806
807 unsigned NPreds = CurrentBB->numPredecessors();
808 unsigned ESz = CurrentLVarMap.size();
809 unsigned MSz = Map.size();
810 unsigned Sz = std::min(a: ESz, b: MSz);
811
812 for (unsigned i = 0; i < Sz; ++i) {
813 if (CurrentLVarMap[i].first != Map[i].first) {
814 // We've reached the end of variables in common.
815 CurrentLVarMap.makeWritable();
816 CurrentLVarMap.downsize(i);
817 break;
818 }
819 if (CurrentLVarMap[i].second != Map[i].second)
820 makePhiNodeVar(i, NPreds, E: Map[i].second);
821 }
822 if (ESz > MSz) {
823 CurrentLVarMap.makeWritable();
824 CurrentLVarMap.downsize(i: Map.size());
825 }
826}
827
828// Merge a back edge into the current variable map.
829// This will create phi nodes for all variables in the variable map.
830void SExprBuilder::mergeEntryMapBackEdge() {
831 // We don't have definitions for variables on the backedge, because we
832 // haven't gotten that far in the CFG. Thus, when encountering a back edge,
833 // we conservatively create Phi nodes for all variables. Unnecessary Phi
834 // nodes will be marked as incomplete, and stripped out at the end.
835 //
836 // An Phi node is unnecessary if it only refers to itself and one other
837 // variable, e.g. x = Phi(y, y, x) can be reduced to x = y.
838
839 assert(CurrentBlockInfo && "Not processing a block!");
840
841 if (CurrentBlockInfo->HasBackEdges)
842 return;
843 CurrentBlockInfo->HasBackEdges = true;
844
845 CurrentLVarMap.makeWritable();
846 unsigned Sz = CurrentLVarMap.size();
847 unsigned NPreds = CurrentBB->numPredecessors();
848
849 for (unsigned i = 0; i < Sz; ++i)
850 makePhiNodeVar(i, NPreds, E: nullptr);
851}
852
853// Update the phi nodes that were initially created for a back edge
854// once the variable definitions have been computed.
855// I.e., merge the current variable map into the phi nodes for Blk.
856void SExprBuilder::mergePhiNodesBackEdge(const CFGBlock *Blk) {
857 til::BasicBlock *BB = lookupBlock(B: Blk);
858 unsigned ArgIndex = BBInfo[Blk->getBlockID()].ProcessedPredecessors;
859 assert(ArgIndex > 0 && ArgIndex < BB->numPredecessors());
860
861 for (til::SExpr *PE : BB->arguments()) {
862 auto *Ph = dyn_cast_or_null<til::Phi>(Val: PE);
863 assert(Ph && "Expecting Phi Node.");
864 assert(Ph->values()[ArgIndex] == nullptr && "Wrong index for back edge.");
865
866 til::SExpr *E = lookupVarDecl(VD: Ph->clangDecl());
867 assert(E && "Couldn't find local variable for Phi node.");
868 Ph->values()[ArgIndex] = E;
869 }
870}
871
872void SExprBuilder::enterCFG(CFG *Cfg, const NamedDecl *D,
873 const CFGBlock *First) {
874 // Perform initial setup operations.
875 unsigned NBlocks = Cfg->getNumBlockIDs();
876 Scfg = new (Arena) til::SCFG(Arena, NBlocks);
877
878 // allocate all basic blocks immediately, to handle forward references.
879 BBInfo.resize(new_size: NBlocks);
880 BlockMap.resize(new_size: NBlocks, x: nullptr);
881 // create map from clang blockID to til::BasicBlocks
882 for (auto *B : *Cfg) {
883 auto *BB = new (Arena) til::BasicBlock(Arena);
884 BB->reserveInstructions(Nins: B->size());
885 BlockMap[B->getBlockID()] = BB;
886 }
887
888 CurrentBB = lookupBlock(B: &Cfg->getEntry());
889 auto Parms = isa<ObjCMethodDecl>(Val: D) ? cast<ObjCMethodDecl>(Val: D)->parameters()
890 : cast<FunctionDecl>(Val: D)->parameters();
891 for (auto *Pm : Parms) {
892 QualType T = Pm->getType();
893 if (!T.isTrivialType(Context: Pm->getASTContext()))
894 continue;
895
896 // Add parameters to local variable map.
897 // FIXME: right now we emulate params with loads; that should be fixed.
898 til::SExpr *Lp = new (Arena) til::LiteralPtr(Pm);
899 til::SExpr *Ld = new (Arena) til::Load(Lp);
900 til::SExpr *V = addStatement(Ld, nullptr, Pm);
901 addVarDecl(Pm, V);
902 }
903}
904
905void SExprBuilder::enterCFGBlock(const CFGBlock *B) {
906 // Initialize TIL basic block and add it to the CFG.
907 CurrentBB = lookupBlock(B);
908 CurrentBB->reservePredecessors(NumPreds: B->pred_size());
909 Scfg->add(BB: CurrentBB);
910
911 CurrentBlockInfo = &BBInfo[B->getBlockID()];
912
913 // CurrentLVarMap is moved to ExitMap on block exit.
914 // FIXME: the entry block will hold function parameters.
915 // assert(!CurrentLVarMap.valid() && "CurrentLVarMap already initialized.");
916}
917
918void SExprBuilder::handlePredecessor(const CFGBlock *Pred) {
919 // Compute CurrentLVarMap on entry from ExitMaps of predecessors
920
921 CurrentBB->addPredecessor(Pred: BlockMap[Pred->getBlockID()]);
922 BlockInfo *PredInfo = &BBInfo[Pred->getBlockID()];
923 assert(PredInfo->UnprocessedSuccessors > 0);
924
925 if (--PredInfo->UnprocessedSuccessors == 0)
926 mergeEntryMap(Map: std::move(PredInfo->ExitMap));
927 else
928 mergeEntryMap(Map: PredInfo->ExitMap.clone());
929
930 ++CurrentBlockInfo->ProcessedPredecessors;
931}
932
933void SExprBuilder::handlePredecessorBackEdge(const CFGBlock *Pred) {
934 mergeEntryMapBackEdge();
935}
936
937void SExprBuilder::enterCFGBlockBody(const CFGBlock *B) {
938 // The merge*() methods have created arguments.
939 // Push those arguments onto the basic block.
940 CurrentBB->arguments().reserve(
941 Ncp: static_cast<unsigned>(CurrentArguments.size()), A: Arena);
942 for (auto *A : CurrentArguments)
943 CurrentBB->addArgument(V: A);
944}
945
946void SExprBuilder::handleStatement(const Stmt *S) {
947 til::SExpr *E = translate(S, Ctx: nullptr);
948 addStatement(E, S);
949}
950
951void SExprBuilder::handleDestructorCall(const VarDecl *VD,
952 const CXXDestructorDecl *DD) {
953 til::SExpr *Sf = new (Arena) til::LiteralPtr(VD);
954 til::SExpr *Dr = new (Arena) til::LiteralPtr(DD);
955 til::SExpr *Ap = new (Arena) til::Apply(Dr, Sf);
956 til::SExpr *E = new (Arena) til::Call(Ap);
957 addStatement(E, S: nullptr);
958}
959
960void SExprBuilder::exitCFGBlockBody(const CFGBlock *B) {
961 CurrentBB->instructions().reserve(
962 Ncp: static_cast<unsigned>(CurrentInstructions.size()), A: Arena);
963 for (auto *V : CurrentInstructions)
964 CurrentBB->addInstruction(V);
965
966 // Create an appropriate terminator
967 unsigned N = B->succ_size();
968 auto It = B->succ_begin();
969 if (N == 1) {
970 til::BasicBlock *BB = *It ? lookupBlock(B: *It) : nullptr;
971 // TODO: set index
972 unsigned Idx = BB ? BB->findPredecessorIndex(BB: CurrentBB) : 0;
973 auto *Tm = new (Arena) til::Goto(BB, Idx);
974 CurrentBB->setTerminator(Tm);
975 }
976 else if (N == 2) {
977 til::SExpr *C = translate(S: B->getTerminatorCondition(StripParens: true), Ctx: nullptr);
978 til::BasicBlock *BB1 = *It ? lookupBlock(B: *It) : nullptr;
979 ++It;
980 til::BasicBlock *BB2 = *It ? lookupBlock(B: *It) : nullptr;
981 // FIXME: make sure these aren't critical edges.
982 auto *Tm = new (Arena) til::Branch(C, BB1, BB2);
983 CurrentBB->setTerminator(Tm);
984 }
985}
986
987void SExprBuilder::handleSuccessor(const CFGBlock *Succ) {
988 ++CurrentBlockInfo->UnprocessedSuccessors;
989}
990
991void SExprBuilder::handleSuccessorBackEdge(const CFGBlock *Succ) {
992 mergePhiNodesBackEdge(Blk: Succ);
993 ++BBInfo[Succ->getBlockID()].ProcessedPredecessors;
994}
995
996void SExprBuilder::exitCFGBlock(const CFGBlock *B) {
997 CurrentArguments.clear();
998 CurrentInstructions.clear();
999 CurrentBlockInfo->ExitMap = std::move(CurrentLVarMap);
1000 CurrentBB = nullptr;
1001 CurrentBlockInfo = nullptr;
1002}
1003
1004void SExprBuilder::exitCFG(const CFGBlock *Last) {
1005 for (auto *Ph : IncompleteArgs) {
1006 if (Ph->status() == til::Phi::PH_Incomplete)
1007 simplifyIncompleteArg(Ph);
1008 }
1009
1010 CurrentArguments.clear();
1011 CurrentInstructions.clear();
1012 IncompleteArgs.clear();
1013}
1014
1015#ifndef NDEBUG
1016namespace {
1017
1018class TILPrinter :
1019 public til::PrettyPrinter<TILPrinter, llvm::raw_ostream> {};
1020
1021} // namespace
1022
1023namespace clang {
1024namespace threadSafety {
1025
1026void printSCFG(CFGWalker &Walker) {
1027 llvm::BumpPtrAllocator Bpa;
1028 til::MemRegionRef Arena(&Bpa);
1029 SExprBuilder SxBuilder(Arena);
1030 til::SCFG *Scfg = SxBuilder.buildCFG(Walker);
1031 TILPrinter::print(E: Scfg, SS&: llvm::errs());
1032}
1033
1034} // namespace threadSafety
1035} // namespace clang
1036#endif // NDEBUG
1037

source code of clang/lib/Analysis/ThreadSafetyCommon.cpp