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 "llvm/Support/Casting.h"
32#include <algorithm>
33#include <cassert>
34#include <string>
35#include <utility>
36
37using namespace clang;
38using namespace threadSafety;
39
40// From ThreadSafetyUtil.h
41std::string threadSafety::getSourceLiteralString(const Expr *CE) {
42 switch (CE->getStmtClass()) {
43 case Stmt::IntegerLiteralClass:
44 return toString(cast<IntegerLiteral>(Val: CE)->getValue(), 10, true);
45 case Stmt::StringLiteralClass: {
46 std::string ret("\"");
47 ret += cast<StringLiteral>(Val: CE)->getString();
48 ret += "\"";
49 return ret;
50 }
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:
58 default:
59 return "#lit";
60 }
61}
62
63// Return true if E is a variable that points to an incomplete Phi node.
64static bool isIncompletePhi(const til::SExpr *E) {
65 if (const auto *Ph = dyn_cast<til::Phi>(Val: E))
66 return Ph->status() == til::Phi::PH_Incomplete;
67 return false;
68}
69
70using CallingContext = SExprBuilder::CallingContext;
71
72til::SExpr *SExprBuilder::lookupStmt(const Stmt *S) { return SMap.lookup(Val: S); }
73
74til::SCFG *SExprBuilder::buildCFG(CFGWalker &Walker) {
75 Walker.walk(V&: *this);
76 return Scfg;
77}
78
79static bool isCalleeArrow(const Expr *E) {
80 const auto *ME = dyn_cast<MemberExpr>(Val: E->IgnoreParenCasts());
81 return ME ? ME->isArrow() : false;
82}
83
84static StringRef ClassifyDiagnostic(const CapabilityAttr *A) {
85 return A->getName();
86}
87
88static StringRef ClassifyDiagnostic(QualType VDT) {
89 // We need to look at the declaration of the type of the value to determine
90 // which it is. The type should either be a record or a typedef, or a pointer
91 // or reference thereof.
92 if (const auto *RT = VDT->getAs<RecordType>()) {
93 if (const auto *RD = RT->getDecl())
94 if (const auto *CA = RD->getAttr<CapabilityAttr>())
95 return ClassifyDiagnostic(CA);
96 } else if (const auto *TT = VDT->getAs<TypedefType>()) {
97 if (const auto *TD = TT->getDecl())
98 if (const auto *CA = TD->getAttr<CapabilityAttr>())
99 return ClassifyDiagnostic(CA);
100 } else if (VDT->isPointerType() || VDT->isReferenceType())
101 return ClassifyDiagnostic(VDT: VDT->getPointeeType());
102
103 return "mutex";
104}
105
106/// Translate a clang expression in an attribute to a til::SExpr.
107/// Constructs the context from D, DeclExp, and SelfDecl.
108///
109/// \param AttrExp The expression to translate.
110/// \param D The declaration to which the attribute is attached.
111/// \param DeclExp An expression involving the Decl to which the attribute
112/// is attached. E.g. the call to a function.
113/// \param Self S-expression to substitute for a \ref CXXThisExpr in a call,
114/// or argument to a cleanup function.
115CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
116 const NamedDecl *D,
117 const Expr *DeclExp,
118 til::SExpr *Self) {
119 // If we are processing a raw attribute expression, with no substitutions.
120 if (!DeclExp && !Self)
121 return translateAttrExpr(AttrExp, Ctx: nullptr);
122
123 CallingContext Ctx(nullptr, D);
124
125 // Examine DeclExp to find SelfArg and FunArgs, which are used to substitute
126 // for formal parameters when we call buildMutexID later.
127 if (!DeclExp)
128 /* We'll use Self. */;
129 else if (const auto *ME = dyn_cast<MemberExpr>(Val: DeclExp)) {
130 Ctx.SelfArg = ME->getBase();
131 Ctx.SelfArrow = ME->isArrow();
132 } else if (const auto *CE = dyn_cast<CXXMemberCallExpr>(Val: DeclExp)) {
133 Ctx.SelfArg = CE->getImplicitObjectArgument();
134 Ctx.SelfArrow = isCalleeArrow(CE->getCallee());
135 Ctx.NumArgs = CE->getNumArgs();
136 Ctx.FunArgs = CE->getArgs();
137 } else if (const auto *CE = dyn_cast<CallExpr>(Val: DeclExp)) {
138 Ctx.NumArgs = CE->getNumArgs();
139 Ctx.FunArgs = CE->getArgs();
140 } else if (const auto *CE = dyn_cast<CXXConstructExpr>(Val: DeclExp)) {
141 Ctx.SelfArg = nullptr; // Will be set below
142 Ctx.NumArgs = CE->getNumArgs();
143 Ctx.FunArgs = CE->getArgs();
144 }
145
146 if (Self) {
147 assert(!Ctx.SelfArg && "Ambiguous self argument");
148 assert(isa<FunctionDecl>(D) && "Self argument requires function");
149 if (isa<CXXMethodDecl>(Val: D))
150 Ctx.SelfArg = Self;
151 else
152 Ctx.FunArgs = Self;
153
154 // If the attribute has no arguments, then assume the argument is "this".
155 if (!AttrExp)
156 return CapabilityExpr(
157 Self,
158 ClassifyDiagnostic(
159 VDT: cast<CXXMethodDecl>(Val: D)->getFunctionObjectParameterType()),
160 false);
161 else // For most attributes.
162 return translateAttrExpr(AttrExp, Ctx: &Ctx);
163 }
164
165 // If the attribute has no arguments, then assume the argument is "this".
166 if (!AttrExp)
167 return translateAttrExpr(AttrExp: cast<const Expr *>(Val&: Ctx.SelfArg), Ctx: nullptr);
168 else // For most attributes.
169 return translateAttrExpr(AttrExp, Ctx: &Ctx);
170}
171
172/// Translate a clang expression in an attribute to a til::SExpr.
173// This assumes a CallingContext has already been created.
174CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
175 CallingContext *Ctx) {
176 if (!AttrExp)
177 return CapabilityExpr();
178
179 if (const auto* SLit = dyn_cast<StringLiteral>(Val: AttrExp)) {
180 if (SLit->getString() == StringRef("*"))
181 // The "*" expr is a universal lock, which essentially turns off
182 // checks until it is removed from the lockset.
183 return CapabilityExpr(new (Arena) til::Wildcard(), StringRef("wildcard"),
184 false);
185 else
186 // Ignore other string literals for now.
187 return CapabilityExpr();
188 }
189
190 bool Neg = false;
191 if (const auto *OE = dyn_cast<CXXOperatorCallExpr>(Val: AttrExp)) {
192 if (OE->getOperator() == OO_Exclaim) {
193 Neg = true;
194 AttrExp = OE->getArg(0);
195 }
196 }
197 else if (const auto *UO = dyn_cast<UnaryOperator>(Val: AttrExp)) {
198 if (UO->getOpcode() == UO_LNot) {
199 Neg = true;
200 AttrExp = UO->getSubExpr();
201 }
202 }
203
204 til::SExpr *E = translate(AttrExp, Ctx);
205
206 // Trap mutex expressions like nullptr, or 0.
207 // Any literal value is nonsense.
208 if (!E || isa<til::Literal>(Val: E))
209 return CapabilityExpr();
210
211 StringRef Kind = ClassifyDiagnostic(VDT: AttrExp->getType());
212
213 // Hack to deal with smart pointers -- strip off top-level pointer casts.
214 if (const auto *CE = dyn_cast<til::Cast>(E)) {
215 if (CE->castOpcode() == til::CAST_objToPtr)
216 return CapabilityExpr(CE->expr(), Kind, Neg);
217 }
218 return CapabilityExpr(E, Kind, Neg);
219}
220
221til::LiteralPtr *SExprBuilder::createVariable(const VarDecl *VD) {
222 return new (Arena) til::LiteralPtr(VD);
223}
224
225std::pair<til::LiteralPtr *, StringRef>
226SExprBuilder::createThisPlaceholder(const Expr *Exp) {
227 return {new (Arena) til::LiteralPtr(nullptr),
228 ClassifyDiagnostic(VDT: Exp->getType())};
229}
230
231// Translate a clang statement or expression to a TIL expression.
232// Also performs substitution of variables; Ctx provides the context.
233// Dispatches on the type of S.
234til::SExpr *SExprBuilder::translate(const Stmt *S, CallingContext *Ctx) {
235 if (!S)
236 return nullptr;
237
238 // Check if S has already been translated and cached.
239 // This handles the lookup of SSA names for DeclRefExprs here.
240 if (til::SExpr *E = lookupStmt(S))
241 return E;
242
243 switch (S->getStmtClass()) {
244 case Stmt::DeclRefExprClass:
245 return translateDeclRefExpr(DRE: cast<DeclRefExpr>(Val: S), Ctx);
246 case Stmt::CXXThisExprClass:
247 return translateCXXThisExpr(TE: cast<CXXThisExpr>(Val: S), Ctx);
248 case Stmt::MemberExprClass:
249 return translateMemberExpr(ME: cast<MemberExpr>(Val: S), Ctx);
250 case Stmt::ObjCIvarRefExprClass:
251 return translateObjCIVarRefExpr(IVRE: cast<ObjCIvarRefExpr>(Val: S), Ctx);
252 case Stmt::CallExprClass:
253 return translateCallExpr(CE: cast<CallExpr>(Val: S), Ctx);
254 case Stmt::CXXMemberCallExprClass:
255 return translateCXXMemberCallExpr(ME: cast<CXXMemberCallExpr>(Val: S), Ctx);
256 case Stmt::CXXOperatorCallExprClass:
257 return translateCXXOperatorCallExpr(OCE: cast<CXXOperatorCallExpr>(Val: S), Ctx);
258 case Stmt::UnaryOperatorClass:
259 return translateUnaryOperator(UO: cast<UnaryOperator>(Val: S), Ctx);
260 case Stmt::BinaryOperatorClass:
261 case Stmt::CompoundAssignOperatorClass:
262 return translateBinaryOperator(BO: cast<BinaryOperator>(Val: S), Ctx);
263
264 case Stmt::ArraySubscriptExprClass:
265 return translateArraySubscriptExpr(E: cast<ArraySubscriptExpr>(Val: S), Ctx);
266 case Stmt::ConditionalOperatorClass:
267 return translateAbstractConditionalOperator(
268 cast<ConditionalOperator>(Val: S), Ctx);
269 case Stmt::BinaryConditionalOperatorClass:
270 return translateAbstractConditionalOperator(
271 cast<BinaryConditionalOperator>(Val: S), Ctx);
272
273 // We treat these as no-ops
274 case Stmt::ConstantExprClass:
275 return translate(S: cast<ConstantExpr>(Val: S)->getSubExpr(), Ctx);
276 case Stmt::ParenExprClass:
277 return translate(cast<ParenExpr>(Val: S)->getSubExpr(), Ctx);
278 case Stmt::ExprWithCleanupsClass:
279 return translate(S: cast<ExprWithCleanups>(Val: S)->getSubExpr(), Ctx);
280 case Stmt::CXXBindTemporaryExprClass:
281 return translate(cast<CXXBindTemporaryExpr>(Val: S)->getSubExpr(), Ctx);
282 case Stmt::MaterializeTemporaryExprClass:
283 return translate(cast<MaterializeTemporaryExpr>(Val: S)->getSubExpr(), Ctx);
284
285 // Collect all literals
286 case Stmt::CharacterLiteralClass:
287 case Stmt::CXXNullPtrLiteralExprClass:
288 case Stmt::GNUNullExprClass:
289 case Stmt::CXXBoolLiteralExprClass:
290 case Stmt::FloatingLiteralClass:
291 case Stmt::ImaginaryLiteralClass:
292 case Stmt::IntegerLiteralClass:
293 case Stmt::StringLiteralClass:
294 case Stmt::ObjCStringLiteralClass:
295 return new (Arena) til::Literal(cast<Expr>(Val: S));
296
297 case Stmt::DeclStmtClass:
298 return translateDeclStmt(S: cast<DeclStmt>(Val: S), Ctx);
299 default:
300 break;
301 }
302 if (const auto *CE = dyn_cast<CastExpr>(Val: S))
303 return translateCastExpr(CE, Ctx);
304
305 return new (Arena) til::Undefined(S);
306}
307
308til::SExpr *SExprBuilder::translateDeclRefExpr(const DeclRefExpr *DRE,
309 CallingContext *Ctx) {
310 const auto *VD = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
311
312 // Function parameters require substitution and/or renaming.
313 if (const auto *PV = dyn_cast<ParmVarDecl>(VD)) {
314 unsigned I = PV->getFunctionScopeIndex();
315 const DeclContext *D = PV->getDeclContext();
316 if (Ctx && Ctx->FunArgs) {
317 const Decl *Canonical = Ctx->AttrDecl->getCanonicalDecl();
318 if (isa<FunctionDecl>(Val: D)
319 ? (cast<FunctionDecl>(Val: D)->getCanonicalDecl() == Canonical)
320 : (cast<ObjCMethodDecl>(Val: D)->getCanonicalDecl() == Canonical)) {
321 // Substitute call arguments for references to function parameters
322 if (const Expr *const *FunArgs =
323 Ctx->FunArgs.dyn_cast<const Expr *const *>()) {
324 assert(I < Ctx->NumArgs);
325 return translate(FunArgs[I], Ctx->Prev);
326 }
327
328 assert(I == 0);
329 return Ctx->FunArgs.get<til::SExpr *>();
330 }
331 }
332 // Map the param back to the param of the original function declaration
333 // for consistent comparisons.
334 VD = isa<FunctionDecl>(Val: D)
335 ? cast<FunctionDecl>(Val: D)->getCanonicalDecl()->getParamDecl(i: I)
336 : cast<ObjCMethodDecl>(Val: D)->getCanonicalDecl()->getParamDecl(Idx: I);
337 }
338
339 // For non-local variables, treat it as a reference to a named object.
340 return new (Arena) til::LiteralPtr(VD);
341}
342
343til::SExpr *SExprBuilder::translateCXXThisExpr(const CXXThisExpr *TE,
344 CallingContext *Ctx) {
345 // Substitute for 'this'
346 if (Ctx && Ctx->SelfArg) {
347 if (const auto *SelfArg = dyn_cast<const Expr *>(Val&: Ctx->SelfArg))
348 return translate(SelfArg, Ctx->Prev);
349 else
350 return cast<til::SExpr *>(Val&: Ctx->SelfArg);
351 }
352 assert(SelfVar && "We have no variable for 'this'!");
353 return SelfVar;
354}
355
356static const ValueDecl *getValueDeclFromSExpr(const til::SExpr *E) {
357 if (const auto *V = dyn_cast<til::Variable>(Val: E))
358 return V->clangDecl();
359 if (const auto *Ph = dyn_cast<til::Phi>(Val: E))
360 return Ph->clangDecl();
361 if (const auto *P = dyn_cast<til::Project>(Val: E))
362 return P->clangDecl();
363 if (const auto *L = dyn_cast<til::LiteralPtr>(Val: E))
364 return L->clangDecl();
365 return nullptr;
366}
367
368static bool hasAnyPointerType(const til::SExpr *E) {
369 auto *VD = getValueDeclFromSExpr(E);
370 if (VD && VD->getType()->isAnyPointerType())
371 return true;
372 if (const auto *C = dyn_cast<til::Cast>(Val: E))
373 return C->castOpcode() == til::CAST_objToPtr;
374
375 return false;
376}
377
378// Grab the very first declaration of virtual method D
379static const CXXMethodDecl *getFirstVirtualDecl(const CXXMethodDecl *D) {
380 while (true) {
381 D = D->getCanonicalDecl();
382 auto OverriddenMethods = D->overridden_methods();
383 if (OverriddenMethods.begin() == OverriddenMethods.end())
384 return D; // Method does not override anything
385 // FIXME: this does not work with multiple inheritance.
386 D = *OverriddenMethods.begin();
387 }
388 return nullptr;
389}
390
391til::SExpr *SExprBuilder::translateMemberExpr(const MemberExpr *ME,
392 CallingContext *Ctx) {
393 til::SExpr *BE = translate(ME->getBase(), Ctx);
394 til::SExpr *E = new (Arena) til::SApply(BE);
395
396 const auto *D = cast<ValueDecl>(ME->getMemberDecl()->getCanonicalDecl());
397 if (const auto *VD = dyn_cast<CXXMethodDecl>(D))
398 D = getFirstVirtualDecl(VD);
399
400 til::Project *P = new (Arena) til::Project(E, D);
401 if (hasAnyPointerType(E: BE))
402 P->setArrow(true);
403 return P;
404}
405
406til::SExpr *SExprBuilder::translateObjCIVarRefExpr(const ObjCIvarRefExpr *IVRE,
407 CallingContext *Ctx) {
408 til::SExpr *BE = translate(IVRE->getBase(), Ctx);
409 til::SExpr *E = new (Arena) til::SApply(BE);
410
411 const auto *D = cast<ObjCIvarDecl>(Val: IVRE->getDecl()->getCanonicalDecl());
412
413 til::Project *P = new (Arena) til::Project(E, D);
414 if (hasAnyPointerType(E: BE))
415 P->setArrow(true);
416 return P;
417}
418
419til::SExpr *SExprBuilder::translateCallExpr(const CallExpr *CE,
420 CallingContext *Ctx,
421 const Expr *SelfE) {
422 if (CapabilityExprMode) {
423 // Handle LOCK_RETURNED
424 if (const FunctionDecl *FD = CE->getDirectCallee()) {
425 FD = FD->getMostRecentDecl();
426 if (LockReturnedAttr *At = FD->getAttr<LockReturnedAttr>()) {
427 CallingContext LRCallCtx(Ctx);
428 LRCallCtx.AttrDecl = CE->getDirectCallee();
429 LRCallCtx.SelfArg = SelfE;
430 LRCallCtx.NumArgs = CE->getNumArgs();
431 LRCallCtx.FunArgs = CE->getArgs();
432 return const_cast<til::SExpr *>(
433 translateAttrExpr(At->getArg(), &LRCallCtx).sexpr());
434 }
435 }
436 }
437
438 til::SExpr *E = translate(CE->getCallee(), Ctx);
439 for (const auto *Arg : CE->arguments()) {
440 til::SExpr *A = translate(S: Arg, Ctx);
441 E = new (Arena) til::Apply(E, A);
442 }
443 return new (Arena) til::Call(E, CE);
444}
445
446til::SExpr *SExprBuilder::translateCXXMemberCallExpr(
447 const CXXMemberCallExpr *ME, CallingContext *Ctx) {
448 if (CapabilityExprMode) {
449 // Ignore calls to get() on smart pointers.
450 if (ME->getMethodDecl()->getNameAsString() == "get" &&
451 ME->getNumArgs() == 0) {
452 auto *E = translate(ME->getImplicitObjectArgument(), Ctx);
453 return new (Arena) til::Cast(til::CAST_objToPtr, E);
454 // return E;
455 }
456 }
457 return translateCallExpr(CE: cast<CallExpr>(Val: ME), Ctx,
458 SelfE: ME->getImplicitObjectArgument());
459}
460
461til::SExpr *SExprBuilder::translateCXXOperatorCallExpr(
462 const CXXOperatorCallExpr *OCE, CallingContext *Ctx) {
463 if (CapabilityExprMode) {
464 // Ignore operator * and operator -> on smart pointers.
465 OverloadedOperatorKind k = OCE->getOperator();
466 if (k == OO_Star || k == OO_Arrow) {
467 auto *E = translate(S: OCE->getArg(0), Ctx);
468 return new (Arena) til::Cast(til::CAST_objToPtr, E);
469 // return E;
470 }
471 }
472 return translateCallExpr(CE: cast<CallExpr>(Val: OCE), Ctx);
473}
474
475til::SExpr *SExprBuilder::translateUnaryOperator(const UnaryOperator *UO,
476 CallingContext *Ctx) {
477 switch (UO->getOpcode()) {
478 case UO_PostInc:
479 case UO_PostDec:
480 case UO_PreInc:
481 case UO_PreDec:
482 return new (Arena) til::Undefined(UO);
483
484 case UO_AddrOf:
485 if (CapabilityExprMode) {
486 // interpret &Graph::mu_ as an existential.
487 if (const auto *DRE = dyn_cast<DeclRefExpr>(Val: UO->getSubExpr())) {
488 if (DRE->getDecl()->isCXXInstanceMember()) {
489 // This is a pointer-to-member expression, e.g. &MyClass::mu_.
490 // We interpret this syntax specially, as a wildcard.
491 auto *W = new (Arena) til::Wildcard();
492 return new (Arena) til::Project(W, DRE->getDecl());
493 }
494 }
495 }
496 // otherwise, & is a no-op
497 return translate(UO->getSubExpr(), Ctx);
498
499 // We treat these as no-ops
500 case UO_Deref:
501 case UO_Plus:
502 return translate(UO->getSubExpr(), Ctx);
503
504 case UO_Minus:
505 return new (Arena)
506 til::UnaryOp(til::UOP_Minus, translate(UO->getSubExpr(), Ctx));
507 case UO_Not:
508 return new (Arena)
509 til::UnaryOp(til::UOP_BitNot, translate(UO->getSubExpr(), Ctx));
510 case UO_LNot:
511 return new (Arena)
512 til::UnaryOp(til::UOP_LogicNot, translate(UO->getSubExpr(), Ctx));
513
514 // Currently unsupported
515 case UO_Real:
516 case UO_Imag:
517 case UO_Extension:
518 case UO_Coawait:
519 return new (Arena) til::Undefined(UO);
520 }
521 return new (Arena) til::Undefined(UO);
522}
523
524til::SExpr *SExprBuilder::translateBinOp(til::TIL_BinaryOpcode Op,
525 const BinaryOperator *BO,
526 CallingContext *Ctx, bool Reverse) {
527 til::SExpr *E0 = translate(BO->getLHS(), Ctx);
528 til::SExpr *E1 = translate(BO->getRHS(), Ctx);
529 if (Reverse)
530 return new (Arena) til::BinaryOp(Op, E1, E0);
531 else
532 return new (Arena) til::BinaryOp(Op, E0, E1);
533}
534
535til::SExpr *SExprBuilder::translateBinAssign(til::TIL_BinaryOpcode Op,
536 const BinaryOperator *BO,
537 CallingContext *Ctx,
538 bool Assign) {
539 const Expr *LHS = BO->getLHS();
540 const Expr *RHS = BO->getRHS();
541 til::SExpr *E0 = translate(LHS, Ctx);
542 til::SExpr *E1 = translate(RHS, Ctx);
543
544 const ValueDecl *VD = nullptr;
545 til::SExpr *CV = nullptr;
546 if (const auto *DRE = dyn_cast<DeclRefExpr>(Val: LHS)) {
547 VD = DRE->getDecl();
548 CV = lookupVarDecl(VD);
549 }
550
551 if (!Assign) {
552 til::SExpr *Arg = CV ? CV : new (Arena) til::Load(E0);
553 E1 = new (Arena) til::BinaryOp(Op, Arg, E1);
554 E1 = addStatement(E: E1, S: nullptr, VD);
555 }
556 if (VD && CV)
557 return updateVarDecl(VD, E: E1);
558 return new (Arena) til::Store(E0, E1);
559}
560
561til::SExpr *SExprBuilder::translateBinaryOperator(const BinaryOperator *BO,
562 CallingContext *Ctx) {
563 switch (BO->getOpcode()) {
564 case BO_PtrMemD:
565 case BO_PtrMemI:
566 return new (Arena) til::Undefined(BO);
567
568 case BO_Mul: return translateBinOp(Op: til::BOP_Mul, BO, Ctx);
569 case BO_Div: return translateBinOp(Op: til::BOP_Div, BO, Ctx);
570 case BO_Rem: return translateBinOp(Op: til::BOP_Rem, BO, Ctx);
571 case BO_Add: return translateBinOp(Op: til::BOP_Add, BO, Ctx);
572 case BO_Sub: return translateBinOp(Op: til::BOP_Sub, BO, Ctx);
573 case BO_Shl: return translateBinOp(Op: til::BOP_Shl, BO, Ctx);
574 case BO_Shr: return translateBinOp(Op: til::BOP_Shr, BO, Ctx);
575 case BO_LT: return translateBinOp(Op: til::BOP_Lt, BO, Ctx);
576 case BO_GT: return translateBinOp(Op: til::BOP_Lt, BO, Ctx, Reverse: true);
577 case BO_LE: return translateBinOp(Op: til::BOP_Leq, BO, Ctx);
578 case BO_GE: return translateBinOp(Op: til::BOP_Leq, BO, Ctx, Reverse: true);
579 case BO_EQ: return translateBinOp(Op: til::BOP_Eq, BO, Ctx);
580 case BO_NE: return translateBinOp(Op: til::BOP_Neq, BO, Ctx);
581 case BO_Cmp: return translateBinOp(Op: til::BOP_Cmp, BO, Ctx);
582 case BO_And: return translateBinOp(Op: til::BOP_BitAnd, BO, Ctx);
583 case BO_Xor: return translateBinOp(Op: til::BOP_BitXor, BO, Ctx);
584 case BO_Or: return translateBinOp(Op: til::BOP_BitOr, BO, Ctx);
585 case BO_LAnd: return translateBinOp(Op: til::BOP_LogicAnd, BO, Ctx);
586 case BO_LOr: return translateBinOp(Op: til::BOP_LogicOr, BO, Ctx);
587
588 case BO_Assign: return translateBinAssign(Op: til::BOP_Eq, BO, Ctx, Assign: true);
589 case BO_MulAssign: return translateBinAssign(Op: til::BOP_Mul, BO, Ctx);
590 case BO_DivAssign: return translateBinAssign(Op: til::BOP_Div, BO, Ctx);
591 case BO_RemAssign: return translateBinAssign(Op: til::BOP_Rem, BO, Ctx);
592 case BO_AddAssign: return translateBinAssign(Op: til::BOP_Add, BO, Ctx);
593 case BO_SubAssign: return translateBinAssign(Op: til::BOP_Sub, BO, Ctx);
594 case BO_ShlAssign: return translateBinAssign(Op: til::BOP_Shl, BO, Ctx);
595 case BO_ShrAssign: return translateBinAssign(Op: til::BOP_Shr, BO, Ctx);
596 case BO_AndAssign: return translateBinAssign(Op: til::BOP_BitAnd, BO, Ctx);
597 case BO_XorAssign: return translateBinAssign(Op: til::BOP_BitXor, BO, Ctx);
598 case BO_OrAssign: return translateBinAssign(Op: til::BOP_BitOr, BO, Ctx);
599
600 case BO_Comma:
601 // The clang CFG should have already processed both sides.
602 return translate(BO->getRHS(), Ctx);
603 }
604 return new (Arena) til::Undefined(BO);
605}
606
607til::SExpr *SExprBuilder::translateCastExpr(const CastExpr *CE,
608 CallingContext *Ctx) {
609 CastKind K = CE->getCastKind();
610 switch (K) {
611 case CK_LValueToRValue: {
612 if (const auto *DRE = dyn_cast<DeclRefExpr>(Val: CE->getSubExpr())) {
613 til::SExpr *E0 = lookupVarDecl(VD: DRE->getDecl());
614 if (E0)
615 return E0;
616 }
617 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
618 return E0;
619 // FIXME!! -- get Load working properly
620 // return new (Arena) til::Load(E0);
621 }
622 case CK_NoOp:
623 case CK_DerivedToBase:
624 case CK_UncheckedDerivedToBase:
625 case CK_ArrayToPointerDecay:
626 case CK_FunctionToPointerDecay: {
627 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
628 return E0;
629 }
630 default: {
631 // FIXME: handle different kinds of casts.
632 til::SExpr *E0 = translate(CE->getSubExpr(), Ctx);
633 if (CapabilityExprMode)
634 return E0;
635 return new (Arena) til::Cast(til::CAST_none, E0);
636 }
637 }
638}
639
640til::SExpr *
641SExprBuilder::translateArraySubscriptExpr(const ArraySubscriptExpr *E,
642 CallingContext *Ctx) {
643 til::SExpr *E0 = translate(E->getBase(), Ctx);
644 til::SExpr *E1 = translate(E->getIdx(), Ctx);
645 return new (Arena) til::ArrayIndex(E0, E1);
646}
647
648til::SExpr *
649SExprBuilder::translateAbstractConditionalOperator(
650 const AbstractConditionalOperator *CO, CallingContext *Ctx) {
651 auto *C = translate(CO->getCond(), Ctx);
652 auto *T = translate(CO->getTrueExpr(), Ctx);
653 auto *E = translate(CO->getFalseExpr(), Ctx);
654 return new (Arena) til::IfThenElse(C, T, E);
655}
656
657til::SExpr *
658SExprBuilder::translateDeclStmt(const DeclStmt *S, CallingContext *Ctx) {
659 DeclGroupRef DGrp = S->getDeclGroup();
660 for (auto *I : DGrp) {
661 if (auto *VD = dyn_cast_or_null<VarDecl>(Val: I)) {
662 Expr *E = VD->getInit();
663 til::SExpr* SE = translate(E, Ctx);
664
665 // Add local variables with trivial type to the variable map
666 QualType T = VD->getType();
667 if (T.isTrivialType(Context: VD->getASTContext()))
668 return addVarDecl(VD, SE);
669 else {
670 // TODO: add alloca
671 }
672 }
673 }
674 return nullptr;
675}
676
677// If (E) is non-trivial, then add it to the current basic block, and
678// update the statement map so that S refers to E. Returns a new variable
679// that refers to E.
680// If E is trivial returns E.
681til::SExpr *SExprBuilder::addStatement(til::SExpr* E, const Stmt *S,
682 const ValueDecl *VD) {
683 if (!E || !CurrentBB || E->block() || til::ThreadSafetyTIL::isTrivial(E))
684 return E;
685 if (VD)
686 E = new (Arena) til::Variable(E, VD);
687 CurrentInstructions.push_back(x: E);
688 if (S)
689 insertStmt(S, E);
690 return E;
691}
692
693// Returns the current value of VD, if known, and nullptr otherwise.
694til::SExpr *SExprBuilder::lookupVarDecl(const ValueDecl *VD) {
695 auto It = LVarIdxMap.find(Val: VD);
696 if (It != LVarIdxMap.end()) {
697 assert(CurrentLVarMap[It->second].first == VD);
698 return CurrentLVarMap[It->second].second;
699 }
700 return nullptr;
701}
702
703// if E is a til::Variable, update its clangDecl.
704static void maybeUpdateVD(til::SExpr *E, const ValueDecl *VD) {
705 if (!E)
706 return;
707 if (auto *V = dyn_cast<til::Variable>(Val: E)) {
708 if (!V->clangDecl())
709 V->setClangDecl(VD);
710 }
711}
712
713// Adds a new variable declaration.
714til::SExpr *SExprBuilder::addVarDecl(const ValueDecl *VD, til::SExpr *E) {
715 maybeUpdateVD(E, VD);
716 LVarIdxMap.insert(KV: std::make_pair(x&: VD, y: CurrentLVarMap.size()));
717 CurrentLVarMap.makeWritable();
718 CurrentLVarMap.push_back(Elem: std::make_pair(x&: VD, y&: E));
719 return E;
720}
721
722// Updates a current variable declaration. (E.g. by assignment)
723til::SExpr *SExprBuilder::updateVarDecl(const ValueDecl *VD, til::SExpr *E) {
724 maybeUpdateVD(E, VD);
725 auto It = LVarIdxMap.find(Val: VD);
726 if (It == LVarIdxMap.end()) {
727 til::SExpr *Ptr = new (Arena) til::LiteralPtr(VD);
728 til::SExpr *St = new (Arena) til::Store(Ptr, E);
729 return St;
730 }
731 CurrentLVarMap.makeWritable();
732 CurrentLVarMap.elem(i: It->second).second = E;
733 return E;
734}
735
736// Make a Phi node in the current block for the i^th variable in CurrentVarMap.
737// If E != null, sets Phi[CurrentBlockInfo->ArgIndex] = E.
738// If E == null, this is a backedge and will be set later.
739void SExprBuilder::makePhiNodeVar(unsigned i, unsigned NPreds, til::SExpr *E) {
740 unsigned ArgIndex = CurrentBlockInfo->ProcessedPredecessors;
741 assert(ArgIndex > 0 && ArgIndex < NPreds);
742
743 til::SExpr *CurrE = CurrentLVarMap[i].second;
744 if (CurrE->block() == CurrentBB) {
745 // We already have a Phi node in the current block,
746 // so just add the new variable to the Phi node.
747 auto *Ph = dyn_cast<til::Phi>(Val: CurrE);
748 assert(Ph && "Expecting Phi node.");
749 if (E)
750 Ph->values()[ArgIndex] = E;
751 return;
752 }
753
754 // Make a new phi node: phi(..., E)
755 // All phi args up to the current index are set to the current value.
756 til::Phi *Ph = new (Arena) til::Phi(Arena, NPreds);
757 Ph->values().setValues(Sz: NPreds, C: nullptr);
758 for (unsigned PIdx = 0; PIdx < ArgIndex; ++PIdx)
759 Ph->values()[PIdx] = CurrE;
760 if (E)
761 Ph->values()[ArgIndex] = E;
762 Ph->setClangDecl(CurrentLVarMap[i].first);
763 // If E is from a back-edge, or either E or CurrE are incomplete, then
764 // mark this node as incomplete; we may need to remove it later.
765 if (!E || isIncompletePhi(E) || isIncompletePhi(E: CurrE))
766 Ph->setStatus(til::Phi::PH_Incomplete);
767
768 // Add Phi node to current block, and update CurrentLVarMap[i]
769 CurrentArguments.push_back(x: Ph);
770 if (Ph->status() == til::Phi::PH_Incomplete)
771 IncompleteArgs.push_back(x: Ph);
772
773 CurrentLVarMap.makeWritable();
774 CurrentLVarMap.elem(i).second = Ph;
775}
776
777// Merge values from Map into the current variable map.
778// This will construct Phi nodes in the current basic block as necessary.
779void SExprBuilder::mergeEntryMap(LVarDefinitionMap Map) {
780 assert(CurrentBlockInfo && "Not processing a block!");
781
782 if (!CurrentLVarMap.valid()) {
783 // Steal Map, using copy-on-write.
784 CurrentLVarMap = std::move(Map);
785 return;
786 }
787 if (CurrentLVarMap.sameAs(V: Map))
788 return; // Easy merge: maps from different predecessors are unchanged.
789
790 unsigned NPreds = CurrentBB->numPredecessors();
791 unsigned ESz = CurrentLVarMap.size();
792 unsigned MSz = Map.size();
793 unsigned Sz = std::min(a: ESz, b: MSz);
794
795 for (unsigned i = 0; i < Sz; ++i) {
796 if (CurrentLVarMap[i].first != Map[i].first) {
797 // We've reached the end of variables in common.
798 CurrentLVarMap.makeWritable();
799 CurrentLVarMap.downsize(i);
800 break;
801 }
802 if (CurrentLVarMap[i].second != Map[i].second)
803 makePhiNodeVar(i, NPreds, E: Map[i].second);
804 }
805 if (ESz > MSz) {
806 CurrentLVarMap.makeWritable();
807 CurrentLVarMap.downsize(i: Map.size());
808 }
809}
810
811// Merge a back edge into the current variable map.
812// This will create phi nodes for all variables in the variable map.
813void SExprBuilder::mergeEntryMapBackEdge() {
814 // We don't have definitions for variables on the backedge, because we
815 // haven't gotten that far in the CFG. Thus, when encountering a back edge,
816 // we conservatively create Phi nodes for all variables. Unnecessary Phi
817 // nodes will be marked as incomplete, and stripped out at the end.
818 //
819 // An Phi node is unnecessary if it only refers to itself and one other
820 // variable, e.g. x = Phi(y, y, x) can be reduced to x = y.
821
822 assert(CurrentBlockInfo && "Not processing a block!");
823
824 if (CurrentBlockInfo->HasBackEdges)
825 return;
826 CurrentBlockInfo->HasBackEdges = true;
827
828 CurrentLVarMap.makeWritable();
829 unsigned Sz = CurrentLVarMap.size();
830 unsigned NPreds = CurrentBB->numPredecessors();
831
832 for (unsigned i = 0; i < Sz; ++i)
833 makePhiNodeVar(i, NPreds, E: nullptr);
834}
835
836// Update the phi nodes that were initially created for a back edge
837// once the variable definitions have been computed.
838// I.e., merge the current variable map into the phi nodes for Blk.
839void SExprBuilder::mergePhiNodesBackEdge(const CFGBlock *Blk) {
840 til::BasicBlock *BB = lookupBlock(B: Blk);
841 unsigned ArgIndex = BBInfo[Blk->getBlockID()].ProcessedPredecessors;
842 assert(ArgIndex > 0 && ArgIndex < BB->numPredecessors());
843
844 for (til::SExpr *PE : BB->arguments()) {
845 auto *Ph = dyn_cast_or_null<til::Phi>(Val: PE);
846 assert(Ph && "Expecting Phi Node.");
847 assert(Ph->values()[ArgIndex] == nullptr && "Wrong index for back edge.");
848
849 til::SExpr *E = lookupVarDecl(VD: Ph->clangDecl());
850 assert(E && "Couldn't find local variable for Phi node.");
851 Ph->values()[ArgIndex] = E;
852 }
853}
854
855void SExprBuilder::enterCFG(CFG *Cfg, const NamedDecl *D,
856 const CFGBlock *First) {
857 // Perform initial setup operations.
858 unsigned NBlocks = Cfg->getNumBlockIDs();
859 Scfg = new (Arena) til::SCFG(Arena, NBlocks);
860
861 // allocate all basic blocks immediately, to handle forward references.
862 BBInfo.resize(new_size: NBlocks);
863 BlockMap.resize(new_size: NBlocks, x: nullptr);
864 // create map from clang blockID to til::BasicBlocks
865 for (auto *B : *Cfg) {
866 auto *BB = new (Arena) til::BasicBlock(Arena);
867 BB->reserveInstructions(Nins: B->size());
868 BlockMap[B->getBlockID()] = BB;
869 }
870
871 CurrentBB = lookupBlock(B: &Cfg->getEntry());
872 auto Parms = isa<ObjCMethodDecl>(Val: D) ? cast<ObjCMethodDecl>(Val: D)->parameters()
873 : cast<FunctionDecl>(Val: D)->parameters();
874 for (auto *Pm : Parms) {
875 QualType T = Pm->getType();
876 if (!T.isTrivialType(Context: Pm->getASTContext()))
877 continue;
878
879 // Add parameters to local variable map.
880 // FIXME: right now we emulate params with loads; that should be fixed.
881 til::SExpr *Lp = new (Arena) til::LiteralPtr(Pm);
882 til::SExpr *Ld = new (Arena) til::Load(Lp);
883 til::SExpr *V = addStatement(Ld, nullptr, Pm);
884 addVarDecl(Pm, V);
885 }
886}
887
888void SExprBuilder::enterCFGBlock(const CFGBlock *B) {
889 // Initialize TIL basic block and add it to the CFG.
890 CurrentBB = lookupBlock(B);
891 CurrentBB->reservePredecessors(NumPreds: B->pred_size());
892 Scfg->add(BB: CurrentBB);
893
894 CurrentBlockInfo = &BBInfo[B->getBlockID()];
895
896 // CurrentLVarMap is moved to ExitMap on block exit.
897 // FIXME: the entry block will hold function parameters.
898 // assert(!CurrentLVarMap.valid() && "CurrentLVarMap already initialized.");
899}
900
901void SExprBuilder::handlePredecessor(const CFGBlock *Pred) {
902 // Compute CurrentLVarMap on entry from ExitMaps of predecessors
903
904 CurrentBB->addPredecessor(Pred: BlockMap[Pred->getBlockID()]);
905 BlockInfo *PredInfo = &BBInfo[Pred->getBlockID()];
906 assert(PredInfo->UnprocessedSuccessors > 0);
907
908 if (--PredInfo->UnprocessedSuccessors == 0)
909 mergeEntryMap(Map: std::move(PredInfo->ExitMap));
910 else
911 mergeEntryMap(Map: PredInfo->ExitMap.clone());
912
913 ++CurrentBlockInfo->ProcessedPredecessors;
914}
915
916void SExprBuilder::handlePredecessorBackEdge(const CFGBlock *Pred) {
917 mergeEntryMapBackEdge();
918}
919
920void SExprBuilder::enterCFGBlockBody(const CFGBlock *B) {
921 // The merge*() methods have created arguments.
922 // Push those arguments onto the basic block.
923 CurrentBB->arguments().reserve(
924 Ncp: static_cast<unsigned>(CurrentArguments.size()), A: Arena);
925 for (auto *A : CurrentArguments)
926 CurrentBB->addArgument(V: A);
927}
928
929void SExprBuilder::handleStatement(const Stmt *S) {
930 til::SExpr *E = translate(S, Ctx: nullptr);
931 addStatement(E, S);
932}
933
934void SExprBuilder::handleDestructorCall(const VarDecl *VD,
935 const CXXDestructorDecl *DD) {
936 til::SExpr *Sf = new (Arena) til::LiteralPtr(VD);
937 til::SExpr *Dr = new (Arena) til::LiteralPtr(DD);
938 til::SExpr *Ap = new (Arena) til::Apply(Dr, Sf);
939 til::SExpr *E = new (Arena) til::Call(Ap);
940 addStatement(E, S: nullptr);
941}
942
943void SExprBuilder::exitCFGBlockBody(const CFGBlock *B) {
944 CurrentBB->instructions().reserve(
945 Ncp: static_cast<unsigned>(CurrentInstructions.size()), A: Arena);
946 for (auto *V : CurrentInstructions)
947 CurrentBB->addInstruction(V);
948
949 // Create an appropriate terminator
950 unsigned N = B->succ_size();
951 auto It = B->succ_begin();
952 if (N == 1) {
953 til::BasicBlock *BB = *It ? lookupBlock(B: *It) : nullptr;
954 // TODO: set index
955 unsigned Idx = BB ? BB->findPredecessorIndex(BB: CurrentBB) : 0;
956 auto *Tm = new (Arena) til::Goto(BB, Idx);
957 CurrentBB->setTerminator(Tm);
958 }
959 else if (N == 2) {
960 til::SExpr *C = translate(S: B->getTerminatorCondition(StripParens: true), Ctx: nullptr);
961 til::BasicBlock *BB1 = *It ? lookupBlock(B: *It) : nullptr;
962 ++It;
963 til::BasicBlock *BB2 = *It ? lookupBlock(B: *It) : nullptr;
964 // FIXME: make sure these aren't critical edges.
965 auto *Tm = new (Arena) til::Branch(C, BB1, BB2);
966 CurrentBB->setTerminator(Tm);
967 }
968}
969
970void SExprBuilder::handleSuccessor(const CFGBlock *Succ) {
971 ++CurrentBlockInfo->UnprocessedSuccessors;
972}
973
974void SExprBuilder::handleSuccessorBackEdge(const CFGBlock *Succ) {
975 mergePhiNodesBackEdge(Blk: Succ);
976 ++BBInfo[Succ->getBlockID()].ProcessedPredecessors;
977}
978
979void SExprBuilder::exitCFGBlock(const CFGBlock *B) {
980 CurrentArguments.clear();
981 CurrentInstructions.clear();
982 CurrentBlockInfo->ExitMap = std::move(CurrentLVarMap);
983 CurrentBB = nullptr;
984 CurrentBlockInfo = nullptr;
985}
986
987void SExprBuilder::exitCFG(const CFGBlock *Last) {
988 for (auto *Ph : IncompleteArgs) {
989 if (Ph->status() == til::Phi::PH_Incomplete)
990 simplifyIncompleteArg(Ph);
991 }
992
993 CurrentArguments.clear();
994 CurrentInstructions.clear();
995 IncompleteArgs.clear();
996}
997
998#ifndef NDEBUG
999namespace {
1000
1001class TILPrinter :
1002 public til::PrettyPrinter<TILPrinter, llvm::raw_ostream> {};
1003
1004} // namespace
1005
1006namespace clang {
1007namespace threadSafety {
1008
1009void printSCFG(CFGWalker &Walker) {
1010 llvm::BumpPtrAllocator Bpa;
1011 til::MemRegionRef Arena(&Bpa);
1012 SExprBuilder SxBuilder(Arena);
1013 til::SCFG *Scfg = SxBuilder.buildCFG(Walker);
1014 TILPrinter::print(E: Scfg, SS&: llvm::errs());
1015}
1016
1017} // namespace threadSafety
1018} // namespace clang
1019#endif // NDEBUG
1020

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