1 //===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file implements semantic analysis for statements.
11 //===----------------------------------------------------------------------===//
13 #include "clang/Sema/Ownership.h"
14 #include "clang/Sema/SemaInternal.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/ASTDiagnostic.h"
17 #include "clang/AST/ASTLambda.h"
18 #include "clang/AST/CharUnits.h"
19 #include "clang/AST/CXXInheritance.h"
20 #include "clang/AST/DeclObjC.h"
21 #include "clang/AST/EvaluatedExprVisitor.h"
22 #include "clang/AST/ExprCXX.h"
23 #include "clang/AST/ExprObjC.h"
24 #include "clang/AST/RecursiveASTVisitor.h"
25 #include "clang/AST/StmtCXX.h"
26 #include "clang/AST/StmtObjC.h"
27 #include "clang/AST/TypeLoc.h"
28 #include "clang/AST/TypeOrdering.h"
29 #include "clang/Basic/TargetInfo.h"
30 #include "clang/Lex/Preprocessor.h"
31 #include "clang/Sema/Initialization.h"
32 #include "clang/Sema/Lookup.h"
33 #include "clang/Sema/Scope.h"
34 #include "clang/Sema/ScopeInfo.h"
35 #include "llvm/ADT/ArrayRef.h"
36 #include "llvm/ADT/DenseMap.h"
37 #include "llvm/ADT/STLExtras.h"
38 #include "llvm/ADT/SmallPtrSet.h"
39 #include "llvm/ADT/SmallString.h"
40 #include "llvm/ADT/SmallVector.h"
42 using namespace clang;
45 StmtResult Sema::ActOnExprStmt(ExprResult FE, bool DiscardedValue) {
49 FE = ActOnFinishFullExpr(FE.get(), FE.get()->getExprLoc(), DiscardedValue);
53 // C99 6.8.3p2: The expression in an expression statement is evaluated as a
54 // void expression for its side effects. Conversion to void allows any
55 // operand, even incomplete types.
57 // Same thing in for stmt first clause (when expr) and third clause.
58 return StmtResult(FE.getAs<Stmt>());
62 StmtResult Sema::ActOnExprStmtError() {
63 DiscardCleanupsInEvaluationContext();
67 StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc,
68 bool HasLeadingEmptyMacro) {
69 return new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro);
72 StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc,
73 SourceLocation EndLoc) {
74 DeclGroupRef DG = dg.get();
76 // If we have an invalid decl, just return an error.
77 if (DG.isNull()) return StmtError();
79 return new (Context) DeclStmt(DG, StartLoc, EndLoc);
82 void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) {
83 DeclGroupRef DG = dg.get();
85 // If we don't have a declaration, or we have an invalid declaration,
87 if (DG.isNull() || !DG.isSingleDecl())
90 Decl *decl = DG.getSingleDecl();
91 if (!decl || decl->isInvalidDecl())
94 // Only variable declarations are permitted.
95 VarDecl *var = dyn_cast<VarDecl>(decl);
97 Diag(decl->getLocation(), diag::err_non_variable_decl_in_for);
98 decl->setInvalidDecl();
102 // foreach variables are never actually initialized in the way that
103 // the parser came up with.
104 var->setInit(nullptr);
106 // In ARC, we don't need to retain the iteration variable of a fast
107 // enumeration loop. Rather than actually trying to catch that
108 // during declaration processing, we remove the consequences here.
109 if (getLangOpts().ObjCAutoRefCount) {
110 QualType type = var->getType();
112 // Only do this if we inferred the lifetime. Inferred lifetime
113 // will show up as a local qualifier because explicit lifetime
114 // should have shown up as an AttributedType instead.
115 if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) {
116 // Add 'const' and mark the variable as pseudo-strong.
117 var->setType(type.withConst());
118 var->setARCPseudoStrong(true);
123 /// Diagnose unused comparisons, both builtin and overloaded operators.
124 /// For '==' and '!=', suggest fixits for '=' or '|='.
126 /// Adding a cast to void (or other expression wrappers) will prevent the
127 /// warning from firing.
128 static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) {
131 enum { Equality, Inequality, Relational, ThreeWay } Kind;
133 if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) {
134 if (!Op->isComparisonOp())
137 if (Op->getOpcode() == BO_EQ)
139 else if (Op->getOpcode() == BO_NE)
141 else if (Op->getOpcode() == BO_Cmp)
144 assert(Op->isRelationalOp());
147 Loc = Op->getOperatorLoc();
148 CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue();
149 } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) {
150 switch (Op->getOperator()) {
154 case OO_ExclaimEqual:
159 case OO_GreaterEqual:
170 Loc = Op->getOperatorLoc();
171 CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue();
173 // Not a typo-prone comparison.
177 // Suppress warnings when the operator, suspicious as it may be, comes from
178 // a macro expansion.
179 if (S.SourceMgr.isMacroBodyExpansion(Loc))
182 S.Diag(Loc, diag::warn_unused_comparison)
183 << (unsigned)Kind << E->getSourceRange();
185 // If the LHS is a plausible entity to assign to, provide a fixit hint to
186 // correct common typos.
188 if (Kind == Inequality)
189 S.Diag(Loc, diag::note_inequality_comparison_to_or_assign)
190 << FixItHint::CreateReplacement(Loc, "|=");
191 else if (Kind == Equality)
192 S.Diag(Loc, diag::note_equality_comparison_to_assign)
193 << FixItHint::CreateReplacement(Loc, "=");
199 static bool DiagnoseNoDiscard(Sema &S, const WarnUnusedResultAttr *A,
200 SourceLocation Loc, SourceRange R1,
201 SourceRange R2, bool IsCtor) {
204 StringRef Msg = A->getMessage();
208 return S.Diag(Loc, diag::warn_unused_constructor) << A << R1 << R2;
209 return S.Diag(Loc, diag::warn_unused_result) << A << R1 << R2;
213 return S.Diag(Loc, diag::warn_unused_constructor_msg) << A << Msg << R1
215 return S.Diag(Loc, diag::warn_unused_result_msg) << A << Msg << R1 << R2;
218 void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
219 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S))
220 return DiagnoseUnusedExprResult(Label->getSubStmt());
222 const Expr *E = dyn_cast_or_null<Expr>(S);
226 // If we are in an unevaluated expression context, then there can be no unused
227 // results because the results aren't expected to be used in the first place.
228 if (isUnevaluatedContext())
231 SourceLocation ExprLoc = E->IgnoreParenImpCasts()->getExprLoc();
232 // In most cases, we don't want to warn if the expression is written in a
233 // macro body, or if the macro comes from a system header. If the offending
234 // expression is a call to a function with the warn_unused_result attribute,
235 // we warn no matter the location. Because of the order in which the various
236 // checks need to happen, we factor out the macro-related test here.
237 bool ShouldSuppress =
238 SourceMgr.isMacroBodyExpansion(ExprLoc) ||
239 SourceMgr.isInSystemMacro(ExprLoc);
241 const Expr *WarnExpr;
244 if (!E->isUnusedResultAWarning(WarnExpr, Loc, R1, R2, Context))
247 // If this is a GNU statement expression expanded from a macro, it is probably
248 // unused because it is a function-like macro that can be used as either an
249 // expression or statement. Don't warn, because it is almost certainly a
251 if (isa<StmtExpr>(E) && Loc.isMacroID())
254 // Check if this is the UNREFERENCED_PARAMETER from the Microsoft headers.
255 // That macro is frequently used to suppress "unused parameter" warnings,
256 // but its implementation makes clang's -Wunused-value fire. Prevent this.
257 if (isa<ParenExpr>(E->IgnoreImpCasts()) && Loc.isMacroID()) {
258 SourceLocation SpellLoc = Loc;
259 if (findMacroSpelling(SpellLoc, "UNREFERENCED_PARAMETER"))
263 // Okay, we have an unused result. Depending on what the base expression is,
264 // we might want to make a more specific diagnostic. Check for one of these
266 unsigned DiagID = diag::warn_unused_expr;
267 if (const FullExpr *Temps = dyn_cast<FullExpr>(E))
268 E = Temps->getSubExpr();
269 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E))
270 E = TempExpr->getSubExpr();
272 if (DiagnoseUnusedComparison(*this, E))
276 if (const auto *Cast = dyn_cast<CastExpr>(E))
277 if (Cast->getCastKind() == CK_NoOp ||
278 Cast->getCastKind() == CK_ConstructorConversion)
279 E = Cast->getSubExpr()->IgnoreImpCasts();
281 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
282 if (E->getType()->isVoidType())
285 if (DiagnoseNoDiscard(*this, cast_or_null<WarnUnusedResultAttr>(
286 CE->getUnusedResultAttr(Context)),
287 Loc, R1, R2, /*isCtor=*/false))
290 // If the callee has attribute pure, const, or warn_unused_result, warn with
291 // a more specific message to make it clear what is happening. If the call
292 // is written in a macro body, only warn if it has the warn_unused_result
294 if (const Decl *FD = CE->getCalleeDecl()) {
297 if (FD->hasAttr<PureAttr>()) {
298 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure";
301 if (FD->hasAttr<ConstAttr>()) {
302 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const";
306 } else if (const auto *CE = dyn_cast<CXXConstructExpr>(E)) {
307 if (const CXXConstructorDecl *Ctor = CE->getConstructor()) {
308 const auto *A = Ctor->getAttr<WarnUnusedResultAttr>();
309 A = A ? A : Ctor->getParent()->getAttr<WarnUnusedResultAttr>();
310 if (DiagnoseNoDiscard(*this, A, Loc, R1, R2, /*isCtor=*/true))
313 } else if (const auto *ILE = dyn_cast<InitListExpr>(E)) {
314 if (const TagDecl *TD = ILE->getType()->getAsTagDecl()) {
316 if (DiagnoseNoDiscard(*this, TD->getAttr<WarnUnusedResultAttr>(), Loc, R1,
317 R2, /*isCtor=*/false))
320 } else if (ShouldSuppress)
324 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
325 if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) {
326 Diag(Loc, diag::err_arc_unused_init_message) << R1;
329 const ObjCMethodDecl *MD = ME->getMethodDecl();
331 if (DiagnoseNoDiscard(*this, MD->getAttr<WarnUnusedResultAttr>(), Loc, R1,
332 R2, /*isCtor=*/false))
335 } else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) {
336 const Expr *Source = POE->getSyntacticForm();
337 if (isa<ObjCSubscriptRefExpr>(Source))
338 DiagID = diag::warn_unused_container_subscript_expr;
340 DiagID = diag::warn_unused_property_expr;
341 } else if (const CXXFunctionalCastExpr *FC
342 = dyn_cast<CXXFunctionalCastExpr>(E)) {
343 const Expr *E = FC->getSubExpr();
344 if (const CXXBindTemporaryExpr *TE = dyn_cast<CXXBindTemporaryExpr>(E))
345 E = TE->getSubExpr();
346 if (isa<CXXTemporaryObjectExpr>(E))
348 if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(E))
349 if (const CXXRecordDecl *RD = CE->getType()->getAsCXXRecordDecl())
350 if (!RD->getAttr<WarnUnusedAttr>())
353 // Diagnose "(void*) blah" as a typo for "(void) blah".
354 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) {
355 TypeSourceInfo *TI = CE->getTypeInfoAsWritten();
356 QualType T = TI->getType();
358 // We really do want to use the non-canonical type here.
359 if (T == Context.VoidPtrTy) {
360 PointerTypeLoc TL = TI->getTypeLoc().castAs<PointerTypeLoc>();
362 Diag(Loc, diag::warn_unused_voidptr)
363 << FixItHint::CreateRemoval(TL.getStarLoc());
368 if (E->isGLValue() && E->getType().isVolatileQualified()) {
369 Diag(Loc, diag::warn_unused_volatile) << R1 << R2;
373 DiagRuntimeBehavior(Loc, nullptr, PDiag(DiagID) << R1 << R2);
376 void Sema::ActOnStartOfCompoundStmt(bool IsStmtExpr) {
377 PushCompoundScope(IsStmtExpr);
380 void Sema::ActOnFinishOfCompoundStmt() {
384 sema::CompoundScopeInfo &Sema::getCurCompoundScope() const {
385 return getCurFunction()->CompoundScopes.back();
388 StmtResult Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
389 ArrayRef<Stmt *> Elts, bool isStmtExpr) {
390 const unsigned NumElts = Elts.size();
392 // If we're in C89 mode, check that we don't have any decls after stmts. If
393 // so, emit an extension diagnostic.
394 if (!getLangOpts().C99 && !getLangOpts().CPlusPlus) {
395 // Note that __extension__ can be around a decl.
397 // Skip over all declarations.
398 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i)
401 // We found the end of the list or a statement. Scan for another declstmt.
402 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i)
406 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin();
407 Diag(D->getLocation(), diag::ext_mixed_decls_code);
411 // Check for suspicious empty body (null statement) in `for' and `while'
412 // statements. Don't do anything for template instantiations, this just adds
414 if (NumElts != 0 && !CurrentInstantiationScope &&
415 getCurCompoundScope().HasEmptyLoopBodies) {
416 for (unsigned i = 0; i != NumElts - 1; ++i)
417 DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]);
420 return CompoundStmt::Create(Context, Elts, L, R);
424 Sema::ActOnCaseExpr(SourceLocation CaseLoc, ExprResult Val) {
428 if (DiagnoseUnexpandedParameterPack(Val.get()))
431 // If we're not inside a switch, let the 'case' statement handling diagnose
432 // this. Just clean up after the expression as best we can.
433 if (getCurFunction()->SwitchStack.empty())
434 return ActOnFinishFullExpr(Val.get(), Val.get()->getExprLoc(), false,
435 getLangOpts().CPlusPlus11);
438 getCurFunction()->SwitchStack.back().getPointer()->getCond();
441 QualType CondType = CondExpr->getType();
443 auto CheckAndFinish = [&](Expr *E) {
444 if (CondType->isDependentType() || E->isTypeDependent())
445 return ExprResult(E);
447 if (getLangOpts().CPlusPlus11) {
448 // C++11 [stmt.switch]p2: the constant-expression shall be a converted
449 // constant expression of the promoted type of the switch condition.
450 llvm::APSInt TempVal;
451 return CheckConvertedConstantExpression(E, CondType, TempVal,
456 if (!E->isValueDependent())
457 ER = VerifyIntegerConstantExpression(E);
459 ER = DefaultLvalueConversion(ER.get());
461 ER = ImpCastExprToType(ER.get(), CondType, CK_IntegralCast);
463 ER = ActOnFinishFullExpr(ER.get(), ER.get()->getExprLoc(), false);
467 ExprResult Converted = CorrectDelayedTyposInExpr(Val, CheckAndFinish);
468 if (Converted.get() == Val.get())
469 Converted = CheckAndFinish(Val.get());
474 Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprResult LHSVal,
475 SourceLocation DotDotDotLoc, ExprResult RHSVal,
476 SourceLocation ColonLoc) {
477 assert((LHSVal.isInvalid() || LHSVal.get()) && "missing LHS value");
478 assert((DotDotDotLoc.isInvalid() ? RHSVal.isUnset()
479 : RHSVal.isInvalid() || RHSVal.get()) &&
480 "missing RHS value");
482 if (getCurFunction()->SwitchStack.empty()) {
483 Diag(CaseLoc, diag::err_case_not_in_switch);
487 if (LHSVal.isInvalid() || RHSVal.isInvalid()) {
488 getCurFunction()->SwitchStack.back().setInt(true);
492 auto *CS = CaseStmt::Create(Context, LHSVal.get(), RHSVal.get(),
493 CaseLoc, DotDotDotLoc, ColonLoc);
494 getCurFunction()->SwitchStack.back().getPointer()->addSwitchCase(CS);
498 /// ActOnCaseStmtBody - This installs a statement as the body of a case.
499 void Sema::ActOnCaseStmtBody(Stmt *S, Stmt *SubStmt) {
500 cast<CaseStmt>(S)->setSubStmt(SubStmt);
504 Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
505 Stmt *SubStmt, Scope *CurScope) {
506 if (getCurFunction()->SwitchStack.empty()) {
507 Diag(DefaultLoc, diag::err_default_not_in_switch);
511 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt);
512 getCurFunction()->SwitchStack.back().getPointer()->addSwitchCase(DS);
517 Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl,
518 SourceLocation ColonLoc, Stmt *SubStmt) {
519 // If the label was multiply defined, reject it now.
520 if (TheDecl->getStmt()) {
521 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName();
522 Diag(TheDecl->getLocation(), diag::note_previous_definition);
526 // Otherwise, things are good. Fill in the declaration and return it.
527 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt);
528 TheDecl->setStmt(LS);
529 if (!TheDecl->isGnuLocal()) {
530 TheDecl->setLocStart(IdentLoc);
531 if (!TheDecl->isMSAsmLabel()) {
532 // Don't update the location of MS ASM labels. These will result in
533 // a diagnostic, and changing the location here will mess that up.
534 TheDecl->setLocation(IdentLoc);
540 StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc,
541 ArrayRef<const Attr*> Attrs,
543 // Fill in the declaration and return it.
544 AttributedStmt *LS = AttributedStmt::Create(Context, AttrLoc, Attrs, SubStmt);
549 class CommaVisitor : public EvaluatedExprVisitor<CommaVisitor> {
550 typedef EvaluatedExprVisitor<CommaVisitor> Inherited;
553 CommaVisitor(Sema &SemaRef) : Inherited(SemaRef.Context), SemaRef(SemaRef) {}
554 void VisitBinaryOperator(BinaryOperator *E) {
555 if (E->getOpcode() == BO_Comma)
556 SemaRef.DiagnoseCommaOperator(E->getLHS(), E->getExprLoc());
557 EvaluatedExprVisitor<CommaVisitor>::VisitBinaryOperator(E);
563 Sema::ActOnIfStmt(SourceLocation IfLoc, bool IsConstexpr, Stmt *InitStmt,
564 ConditionResult Cond,
565 Stmt *thenStmt, SourceLocation ElseLoc,
567 if (Cond.isInvalid())
568 Cond = ConditionResult(
570 MakeFullExpr(new (Context) OpaqueValueExpr(SourceLocation(),
571 Context.BoolTy, VK_RValue),
575 Expr *CondExpr = Cond.get().second;
576 // Only call the CommaVisitor when not C89 due to differences in scope flags.
577 if ((getLangOpts().C99 || getLangOpts().CPlusPlus) &&
578 !Diags.isIgnored(diag::warn_comma_operator, CondExpr->getExprLoc()))
579 CommaVisitor(*this).Visit(CondExpr);
582 DiagnoseEmptyStmtBody(CondExpr->getEndLoc(), thenStmt,
583 diag::warn_empty_if_body);
585 return BuildIfStmt(IfLoc, IsConstexpr, InitStmt, Cond, thenStmt, ElseLoc,
589 StmtResult Sema::BuildIfStmt(SourceLocation IfLoc, bool IsConstexpr,
590 Stmt *InitStmt, ConditionResult Cond,
591 Stmt *thenStmt, SourceLocation ElseLoc,
593 if (Cond.isInvalid())
596 if (IsConstexpr || isa<ObjCAvailabilityCheckExpr>(Cond.get().second))
597 setFunctionHasBranchProtectedScope();
599 return IfStmt::Create(Context, IfLoc, IsConstexpr, InitStmt, Cond.get().first,
600 Cond.get().second, thenStmt, ElseLoc, elseStmt);
604 struct CaseCompareFunctor {
605 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
606 const llvm::APSInt &RHS) {
607 return LHS.first < RHS;
609 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
610 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
611 return LHS.first < RHS.first;
613 bool operator()(const llvm::APSInt &LHS,
614 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
615 return LHS < RHS.first;
620 /// CmpCaseVals - Comparison predicate for sorting case values.
622 static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs,
623 const std::pair<llvm::APSInt, CaseStmt*>& rhs) {
624 if (lhs.first < rhs.first)
627 if (lhs.first == rhs.first &&
628 lhs.second->getCaseLoc().getRawEncoding()
629 < rhs.second->getCaseLoc().getRawEncoding())
634 /// CmpEnumVals - Comparison predicate for sorting enumeration values.
636 static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
637 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
639 return lhs.first < rhs.first;
642 /// EqEnumVals - Comparison preficate for uniqing enumeration values.
644 static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
645 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
647 return lhs.first == rhs.first;
650 /// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of
651 /// potentially integral-promoted expression @p expr.
652 static QualType GetTypeBeforeIntegralPromotion(const Expr *&E) {
653 if (const auto *FE = dyn_cast<FullExpr>(E))
654 E = FE->getSubExpr();
655 while (const auto *ImpCast = dyn_cast<ImplicitCastExpr>(E)) {
656 if (ImpCast->getCastKind() != CK_IntegralCast) break;
657 E = ImpCast->getSubExpr();
662 ExprResult Sema::CheckSwitchCondition(SourceLocation SwitchLoc, Expr *Cond) {
663 class SwitchConvertDiagnoser : public ICEConvertDiagnoser {
667 SwitchConvertDiagnoser(Expr *Cond)
668 : ICEConvertDiagnoser(/*AllowScopedEnumerations*/true, false, true),
671 SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
672 QualType T) override {
673 return S.Diag(Loc, diag::err_typecheck_statement_requires_integer) << T;
676 SemaDiagnosticBuilder diagnoseIncomplete(
677 Sema &S, SourceLocation Loc, QualType T) override {
678 return S.Diag(Loc, diag::err_switch_incomplete_class_type)
679 << T << Cond->getSourceRange();
682 SemaDiagnosticBuilder diagnoseExplicitConv(
683 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
684 return S.Diag(Loc, diag::err_switch_explicit_conversion) << T << ConvTy;
687 SemaDiagnosticBuilder noteExplicitConv(
688 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
689 return S.Diag(Conv->getLocation(), diag::note_switch_conversion)
690 << ConvTy->isEnumeralType() << ConvTy;
693 SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
694 QualType T) override {
695 return S.Diag(Loc, diag::err_switch_multiple_conversions) << T;
698 SemaDiagnosticBuilder noteAmbiguous(
699 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
700 return S.Diag(Conv->getLocation(), diag::note_switch_conversion)
701 << ConvTy->isEnumeralType() << ConvTy;
704 SemaDiagnosticBuilder diagnoseConversion(
705 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
706 llvm_unreachable("conversion functions are permitted");
708 } SwitchDiagnoser(Cond);
710 ExprResult CondResult =
711 PerformContextualImplicitConversion(SwitchLoc, Cond, SwitchDiagnoser);
712 if (CondResult.isInvalid())
715 // FIXME: PerformContextualImplicitConversion doesn't always tell us if it
716 // failed and produced a diagnostic.
717 Cond = CondResult.get();
718 if (!Cond->isTypeDependent() &&
719 !Cond->getType()->isIntegralOrEnumerationType())
722 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr.
723 return UsualUnaryConversions(Cond);
726 StmtResult Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc,
727 Stmt *InitStmt, ConditionResult Cond) {
728 Expr *CondExpr = Cond.get().second;
729 assert((Cond.isInvalid() || CondExpr) && "switch with no condition");
731 if (CondExpr && !CondExpr->isTypeDependent()) {
732 // We have already converted the expression to an integral or enumeration
733 // type, when we parsed the switch condition. If we don't have an
734 // appropriate type now, enter the switch scope but remember that it's
736 assert(CondExpr->getType()->isIntegralOrEnumerationType() &&
737 "invalid condition type");
738 if (CondExpr->isKnownToHaveBooleanValue()) {
739 // switch(bool_expr) {...} is often a programmer error, e.g.
740 // switch(n && mask) { ... } // Doh - should be "n & mask".
741 // One can always use an if statement instead of switch(bool_expr).
742 Diag(SwitchLoc, diag::warn_bool_switch_condition)
743 << CondExpr->getSourceRange();
747 setFunctionHasBranchIntoScope();
749 auto *SS = SwitchStmt::Create(Context, InitStmt, Cond.get().first, CondExpr);
750 getCurFunction()->SwitchStack.push_back(
751 FunctionScopeInfo::SwitchInfo(SS, false));
755 static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) {
756 Val = Val.extOrTrunc(BitWidth);
757 Val.setIsSigned(IsSigned);
760 /// Check the specified case value is in range for the given unpromoted switch
762 static void checkCaseValue(Sema &S, SourceLocation Loc, const llvm::APSInt &Val,
763 unsigned UnpromotedWidth, bool UnpromotedSign) {
764 // In C++11 onwards, this is checked by the language rules.
765 if (S.getLangOpts().CPlusPlus11)
768 // If the case value was signed and negative and the switch expression is
769 // unsigned, don't bother to warn: this is implementation-defined behavior.
770 // FIXME: Introduce a second, default-ignored warning for this case?
771 if (UnpromotedWidth < Val.getBitWidth()) {
772 llvm::APSInt ConvVal(Val);
773 AdjustAPSInt(ConvVal, UnpromotedWidth, UnpromotedSign);
774 AdjustAPSInt(ConvVal, Val.getBitWidth(), Val.isSigned());
775 // FIXME: Use different diagnostics for overflow in conversion to promoted
776 // type versus "switch expression cannot have this value". Use proper
777 // IntRange checking rather than just looking at the unpromoted type here.
779 S.Diag(Loc, diag::warn_case_value_overflow) << Val.toString(10)
780 << ConvVal.toString(10);
784 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> EnumValsTy;
786 /// Returns true if we should emit a diagnostic about this case expression not
787 /// being a part of the enum used in the switch controlling expression.
788 static bool ShouldDiagnoseSwitchCaseNotInEnum(const Sema &S,
790 const Expr *CaseExpr,
791 EnumValsTy::iterator &EI,
792 EnumValsTy::iterator &EIEnd,
793 const llvm::APSInt &Val) {
797 if (const DeclRefExpr *DRE =
798 dyn_cast<DeclRefExpr>(CaseExpr->IgnoreParenImpCasts())) {
799 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
800 QualType VarType = VD->getType();
801 QualType EnumType = S.Context.getTypeDeclType(ED);
802 if (VD->hasGlobalStorage() && VarType.isConstQualified() &&
803 S.Context.hasSameUnqualifiedType(EnumType, VarType))
808 if (ED->hasAttr<FlagEnumAttr>())
809 return !S.IsValueInFlagEnum(ED, Val, false);
811 while (EI != EIEnd && EI->first < Val)
814 if (EI != EIEnd && EI->first == Val)
820 static void checkEnumTypesInSwitchStmt(Sema &S, const Expr *Cond,
822 QualType CondType = Cond->getType();
823 QualType CaseType = Case->getType();
825 const EnumType *CondEnumType = CondType->getAs<EnumType>();
826 const EnumType *CaseEnumType = CaseType->getAs<EnumType>();
827 if (!CondEnumType || !CaseEnumType)
830 // Ignore anonymous enums.
831 if (!CondEnumType->getDecl()->getIdentifier() &&
832 !CondEnumType->getDecl()->getTypedefNameForAnonDecl())
834 if (!CaseEnumType->getDecl()->getIdentifier() &&
835 !CaseEnumType->getDecl()->getTypedefNameForAnonDecl())
838 if (S.Context.hasSameUnqualifiedType(CondType, CaseType))
841 S.Diag(Case->getExprLoc(), diag::warn_comparison_of_mixed_enum_types_switch)
842 << CondType << CaseType << Cond->getSourceRange()
843 << Case->getSourceRange();
847 Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch,
849 SwitchStmt *SS = cast<SwitchStmt>(Switch);
850 bool CaseListIsIncomplete = getCurFunction()->SwitchStack.back().getInt();
851 assert(SS == getCurFunction()->SwitchStack.back().getPointer() &&
852 "switch stack missing push/pop!");
854 getCurFunction()->SwitchStack.pop_back();
856 if (!BodyStmt) return StmtError();
857 SS->setBody(BodyStmt, SwitchLoc);
859 Expr *CondExpr = SS->getCond();
860 if (!CondExpr) return StmtError();
862 QualType CondType = CondExpr->getType();
865 // Integral promotions are performed (on the switch condition).
867 // A case value unrepresentable by the original switch condition
868 // type (before the promotion) doesn't make sense, even when it can
869 // be represented by the promoted type. Therefore we need to find
870 // the pre-promotion type of the switch condition.
871 const Expr *CondExprBeforePromotion = CondExpr;
872 QualType CondTypeBeforePromotion =
873 GetTypeBeforeIntegralPromotion(CondExprBeforePromotion);
875 // Get the bitwidth of the switched-on value after promotions. We must
876 // convert the integer case values to this width before comparison.
877 bool HasDependentValue
878 = CondExpr->isTypeDependent() || CondExpr->isValueDependent();
879 unsigned CondWidth = HasDependentValue ? 0 : Context.getIntWidth(CondType);
880 bool CondIsSigned = CondType->isSignedIntegerOrEnumerationType();
882 // Get the width and signedness that the condition might actually have, for
884 // FIXME: Grab an IntRange for the condition rather than using the unpromoted
886 unsigned CondWidthBeforePromotion
887 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion);
888 bool CondIsSignedBeforePromotion
889 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType();
891 // Accumulate all of the case values in a vector so that we can sort them
892 // and detect duplicates. This vector contains the APInt for the case after
893 // it has been converted to the condition type.
894 typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy;
897 // Keep track of any GNU case ranges we see. The APSInt is the low value.
898 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy;
899 CaseRangesTy CaseRanges;
901 DefaultStmt *TheDefaultStmt = nullptr;
903 bool CaseListIsErroneous = false;
905 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue;
906 SC = SC->getNextSwitchCase()) {
908 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) {
909 if (TheDefaultStmt) {
910 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined);
911 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev);
913 // FIXME: Remove the default statement from the switch block so that
914 // we'll return a valid AST. This requires recursing down the AST and
915 // finding it, not something we are set up to do right now. For now,
916 // just lop the entire switch stmt out of the AST.
917 CaseListIsErroneous = true;
922 CaseStmt *CS = cast<CaseStmt>(SC);
924 Expr *Lo = CS->getLHS();
926 if (Lo->isValueDependent()) {
927 HasDependentValue = true;
931 // We already verified that the expression has a constant value;
932 // get that value (prior to conversions).
933 const Expr *LoBeforePromotion = Lo;
934 GetTypeBeforeIntegralPromotion(LoBeforePromotion);
935 llvm::APSInt LoVal = LoBeforePromotion->EvaluateKnownConstInt(Context);
937 // Check the unconverted value is within the range of possible values of
938 // the switch expression.
939 checkCaseValue(*this, Lo->getBeginLoc(), LoVal, CondWidthBeforePromotion,
940 CondIsSignedBeforePromotion);
942 // FIXME: This duplicates the check performed for warn_not_in_enum below.
943 checkEnumTypesInSwitchStmt(*this, CondExprBeforePromotion,
946 // Convert the value to the same width/sign as the condition.
947 AdjustAPSInt(LoVal, CondWidth, CondIsSigned);
949 // If this is a case range, remember it in CaseRanges, otherwise CaseVals.
951 if (CS->getRHS()->isValueDependent()) {
952 HasDependentValue = true;
955 CaseRanges.push_back(std::make_pair(LoVal, CS));
957 CaseVals.push_back(std::make_pair(LoVal, CS));
961 if (!HasDependentValue) {
962 // If we don't have a default statement, check whether the
963 // condition is constant.
964 llvm::APSInt ConstantCondValue;
965 bool HasConstantCond = false;
966 if (!TheDefaultStmt) {
967 Expr::EvalResult Result;
968 HasConstantCond = CondExpr->EvaluateAsInt(Result, Context,
969 Expr::SE_AllowSideEffects);
970 if (Result.Val.isInt())
971 ConstantCondValue = Result.Val.getInt();
972 assert(!HasConstantCond ||
973 (ConstantCondValue.getBitWidth() == CondWidth &&
974 ConstantCondValue.isSigned() == CondIsSigned));
976 bool ShouldCheckConstantCond = HasConstantCond;
978 // Sort all the scalar case values so we can easily detect duplicates.
979 llvm::stable_sort(CaseVals, CmpCaseVals);
981 if (!CaseVals.empty()) {
982 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) {
983 if (ShouldCheckConstantCond &&
984 CaseVals[i].first == ConstantCondValue)
985 ShouldCheckConstantCond = false;
987 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) {
988 // If we have a duplicate, report it.
989 // First, determine if either case value has a name
990 StringRef PrevString, CurrString;
991 Expr *PrevCase = CaseVals[i-1].second->getLHS()->IgnoreParenCasts();
992 Expr *CurrCase = CaseVals[i].second->getLHS()->IgnoreParenCasts();
993 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(PrevCase)) {
994 PrevString = DeclRef->getDecl()->getName();
996 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(CurrCase)) {
997 CurrString = DeclRef->getDecl()->getName();
999 SmallString<16> CaseValStr;
1000 CaseVals[i-1].first.toString(CaseValStr);
1002 if (PrevString == CurrString)
1003 Diag(CaseVals[i].second->getLHS()->getBeginLoc(),
1004 diag::err_duplicate_case)
1005 << (PrevString.empty() ? StringRef(CaseValStr) : PrevString);
1007 Diag(CaseVals[i].second->getLHS()->getBeginLoc(),
1008 diag::err_duplicate_case_differing_expr)
1009 << (PrevString.empty() ? StringRef(CaseValStr) : PrevString)
1010 << (CurrString.empty() ? StringRef(CaseValStr) : CurrString)
1013 Diag(CaseVals[i - 1].second->getLHS()->getBeginLoc(),
1014 diag::note_duplicate_case_prev);
1015 // FIXME: We really want to remove the bogus case stmt from the
1016 // substmt, but we have no way to do this right now.
1017 CaseListIsErroneous = true;
1022 // Detect duplicate case ranges, which usually don't exist at all in
1024 if (!CaseRanges.empty()) {
1025 // Sort all the case ranges by their low value so we can easily detect
1026 // overlaps between ranges.
1027 llvm::stable_sort(CaseRanges);
1029 // Scan the ranges, computing the high values and removing empty ranges.
1030 std::vector<llvm::APSInt> HiVals;
1031 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
1032 llvm::APSInt &LoVal = CaseRanges[i].first;
1033 CaseStmt *CR = CaseRanges[i].second;
1034 Expr *Hi = CR->getRHS();
1036 const Expr *HiBeforePromotion = Hi;
1037 GetTypeBeforeIntegralPromotion(HiBeforePromotion);
1038 llvm::APSInt HiVal = HiBeforePromotion->EvaluateKnownConstInt(Context);
1040 // Check the unconverted value is within the range of possible values of
1041 // the switch expression.
1042 checkCaseValue(*this, Hi->getBeginLoc(), HiVal,
1043 CondWidthBeforePromotion, CondIsSignedBeforePromotion);
1045 // Convert the value to the same width/sign as the condition.
1046 AdjustAPSInt(HiVal, CondWidth, CondIsSigned);
1048 // If the low value is bigger than the high value, the case is empty.
1049 if (LoVal > HiVal) {
1050 Diag(CR->getLHS()->getBeginLoc(), diag::warn_case_empty_range)
1051 << SourceRange(CR->getLHS()->getBeginLoc(), Hi->getEndLoc());
1052 CaseRanges.erase(CaseRanges.begin()+i);
1058 if (ShouldCheckConstantCond &&
1059 LoVal <= ConstantCondValue &&
1060 ConstantCondValue <= HiVal)
1061 ShouldCheckConstantCond = false;
1063 HiVals.push_back(HiVal);
1066 // Rescan the ranges, looking for overlap with singleton values and other
1067 // ranges. Since the range list is sorted, we only need to compare case
1068 // ranges with their neighbors.
1069 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
1070 llvm::APSInt &CRLo = CaseRanges[i].first;
1071 llvm::APSInt &CRHi = HiVals[i];
1072 CaseStmt *CR = CaseRanges[i].second;
1074 // Check to see whether the case range overlaps with any
1076 CaseStmt *OverlapStmt = nullptr;
1077 llvm::APSInt OverlapVal(32);
1079 // Find the smallest value >= the lower bound. If I is in the
1080 // case range, then we have overlap.
1081 CaseValsTy::iterator I =
1082 llvm::lower_bound(CaseVals, CRLo, CaseCompareFunctor());
1083 if (I != CaseVals.end() && I->first < CRHi) {
1084 OverlapVal = I->first; // Found overlap with scalar.
1085 OverlapStmt = I->second;
1088 // Find the smallest value bigger than the upper bound.
1089 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor());
1090 if (I != CaseVals.begin() && (I-1)->first >= CRLo) {
1091 OverlapVal = (I-1)->first; // Found overlap with scalar.
1092 OverlapStmt = (I-1)->second;
1095 // Check to see if this case stmt overlaps with the subsequent
1097 if (i && CRLo <= HiVals[i-1]) {
1098 OverlapVal = HiVals[i-1]; // Found overlap with range.
1099 OverlapStmt = CaseRanges[i-1].second;
1103 // If we have a duplicate, report it.
1104 Diag(CR->getLHS()->getBeginLoc(), diag::err_duplicate_case)
1105 << OverlapVal.toString(10);
1106 Diag(OverlapStmt->getLHS()->getBeginLoc(),
1107 diag::note_duplicate_case_prev);
1108 // FIXME: We really want to remove the bogus case stmt from the
1109 // substmt, but we have no way to do this right now.
1110 CaseListIsErroneous = true;
1115 // Complain if we have a constant condition and we didn't find a match.
1116 if (!CaseListIsErroneous && !CaseListIsIncomplete &&
1117 ShouldCheckConstantCond) {
1118 // TODO: it would be nice if we printed enums as enums, chars as
1120 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition)
1121 << ConstantCondValue.toString(10)
1122 << CondExpr->getSourceRange();
1125 // Check to see if switch is over an Enum and handles all of its
1126 // values. We only issue a warning if there is not 'default:', but
1127 // we still do the analysis to preserve this information in the AST
1128 // (which can be used by flow-based analyes).
1130 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>();
1132 // If switch has default case, then ignore it.
1133 if (!CaseListIsErroneous && !CaseListIsIncomplete && !HasConstantCond &&
1134 ET && ET->getDecl()->isCompleteDefinition()) {
1135 const EnumDecl *ED = ET->getDecl();
1136 EnumValsTy EnumVals;
1138 // Gather all enum values, set their type and sort them,
1139 // allowing easier comparison with CaseVals.
1140 for (auto *EDI : ED->enumerators()) {
1141 llvm::APSInt Val = EDI->getInitVal();
1142 AdjustAPSInt(Val, CondWidth, CondIsSigned);
1143 EnumVals.push_back(std::make_pair(Val, EDI));
1145 llvm::stable_sort(EnumVals, CmpEnumVals);
1146 auto EI = EnumVals.begin(), EIEnd =
1147 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
1149 // See which case values aren't in enum.
1150 for (CaseValsTy::const_iterator CI = CaseVals.begin();
1151 CI != CaseVals.end(); CI++) {
1152 Expr *CaseExpr = CI->second->getLHS();
1153 if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
1155 Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
1156 << CondTypeBeforePromotion;
1159 // See which of case ranges aren't in enum
1160 EI = EnumVals.begin();
1161 for (CaseRangesTy::const_iterator RI = CaseRanges.begin();
1162 RI != CaseRanges.end(); RI++) {
1163 Expr *CaseExpr = RI->second->getLHS();
1164 if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
1166 Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
1167 << CondTypeBeforePromotion;
1170 RI->second->getRHS()->EvaluateKnownConstInt(Context);
1171 AdjustAPSInt(Hi, CondWidth, CondIsSigned);
1173 CaseExpr = RI->second->getRHS();
1174 if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
1176 Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
1177 << CondTypeBeforePromotion;
1180 // Check which enum vals aren't in switch
1181 auto CI = CaseVals.begin();
1182 auto RI = CaseRanges.begin();
1183 bool hasCasesNotInSwitch = false;
1185 SmallVector<DeclarationName,8> UnhandledNames;
1187 for (EI = EnumVals.begin(); EI != EIEnd; EI++) {
1188 // Don't warn about omitted unavailable EnumConstantDecls.
1189 switch (EI->second->getAvailability()) {
1191 // Omitting a deprecated constant is ok; it should never materialize.
1192 case AR_Unavailable:
1195 case AR_NotYetIntroduced:
1196 // Partially available enum constants should be present. Note that we
1197 // suppress -Wunguarded-availability diagnostics for such uses.
1202 if (EI->second->hasAttr<UnusedAttr>())
1205 // Drop unneeded case values
1206 while (CI != CaseVals.end() && CI->first < EI->first)
1209 if (CI != CaseVals.end() && CI->first == EI->first)
1212 // Drop unneeded case ranges
1213 for (; RI != CaseRanges.end(); RI++) {
1215 RI->second->getRHS()->EvaluateKnownConstInt(Context);
1216 AdjustAPSInt(Hi, CondWidth, CondIsSigned);
1217 if (EI->first <= Hi)
1221 if (RI == CaseRanges.end() || EI->first < RI->first) {
1222 hasCasesNotInSwitch = true;
1223 UnhandledNames.push_back(EI->second->getDeclName());
1227 if (TheDefaultStmt && UnhandledNames.empty() && ED->isClosedNonFlag())
1228 Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default);
1230 // Produce a nice diagnostic if multiple values aren't handled.
1231 if (!UnhandledNames.empty()) {
1232 DiagnosticBuilder DB = Diag(CondExpr->getExprLoc(),
1233 TheDefaultStmt ? diag::warn_def_missing_case
1234 : diag::warn_missing_case)
1235 << (int)UnhandledNames.size();
1237 for (size_t I = 0, E = std::min(UnhandledNames.size(), (size_t)3);
1239 DB << UnhandledNames[I];
1242 if (!hasCasesNotInSwitch)
1243 SS->setAllEnumCasesCovered();
1248 DiagnoseEmptyStmtBody(CondExpr->getEndLoc(), BodyStmt,
1249 diag::warn_empty_switch_body);
1251 // FIXME: If the case list was broken is some way, we don't have a good system
1252 // to patch it up. Instead, just return the whole substmt as broken.
1253 if (CaseListIsErroneous)
1260 Sema::DiagnoseAssignmentEnum(QualType DstType, QualType SrcType,
1262 if (Diags.isIgnored(diag::warn_not_in_enum_assignment, SrcExpr->getExprLoc()))
1265 if (const EnumType *ET = DstType->getAs<EnumType>())
1266 if (!Context.hasSameUnqualifiedType(SrcType, DstType) &&
1267 SrcType->isIntegerType()) {
1268 if (!SrcExpr->isTypeDependent() && !SrcExpr->isValueDependent() &&
1269 SrcExpr->isIntegerConstantExpr(Context)) {
1270 // Get the bitwidth of the enum value before promotions.
1271 unsigned DstWidth = Context.getIntWidth(DstType);
1272 bool DstIsSigned = DstType->isSignedIntegerOrEnumerationType();
1274 llvm::APSInt RhsVal = SrcExpr->EvaluateKnownConstInt(Context);
1275 AdjustAPSInt(RhsVal, DstWidth, DstIsSigned);
1276 const EnumDecl *ED = ET->getDecl();
1278 if (!ED->isClosed())
1281 if (ED->hasAttr<FlagEnumAttr>()) {
1282 if (!IsValueInFlagEnum(ED, RhsVal, true))
1283 Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment)
1284 << DstType.getUnqualifiedType();
1286 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl *>, 64>
1288 EnumValsTy EnumVals;
1290 // Gather all enum values, set their type and sort them,
1291 // allowing easier comparison with rhs constant.
1292 for (auto *EDI : ED->enumerators()) {
1293 llvm::APSInt Val = EDI->getInitVal();
1294 AdjustAPSInt(Val, DstWidth, DstIsSigned);
1295 EnumVals.push_back(std::make_pair(Val, EDI));
1297 if (EnumVals.empty())
1299 llvm::stable_sort(EnumVals, CmpEnumVals);
1300 EnumValsTy::iterator EIend =
1301 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
1303 // See which values aren't in the enum.
1304 EnumValsTy::const_iterator EI = EnumVals.begin();
1305 while (EI != EIend && EI->first < RhsVal)
1307 if (EI == EIend || EI->first != RhsVal) {
1308 Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment)
1309 << DstType.getUnqualifiedType();
1316 StmtResult Sema::ActOnWhileStmt(SourceLocation WhileLoc, ConditionResult Cond,
1318 if (Cond.isInvalid())
1321 auto CondVal = Cond.get();
1322 CheckBreakContinueBinding(CondVal.second);
1324 if (CondVal.second &&
1325 !Diags.isIgnored(diag::warn_comma_operator, CondVal.second->getExprLoc()))
1326 CommaVisitor(*this).Visit(CondVal.second);
1328 if (isa<NullStmt>(Body))
1329 getCurCompoundScope().setHasEmptyLoopBodies();
1331 return WhileStmt::Create(Context, CondVal.first, CondVal.second, Body,
1336 Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body,
1337 SourceLocation WhileLoc, SourceLocation CondLParen,
1338 Expr *Cond, SourceLocation CondRParen) {
1339 assert(Cond && "ActOnDoStmt(): missing expression");
1341 CheckBreakContinueBinding(Cond);
1342 ExprResult CondResult = CheckBooleanCondition(DoLoc, Cond);
1343 if (CondResult.isInvalid())
1345 Cond = CondResult.get();
1347 CondResult = ActOnFinishFullExpr(Cond, DoLoc, /*DiscardedValue*/ false);
1348 if (CondResult.isInvalid())
1350 Cond = CondResult.get();
1352 // Only call the CommaVisitor for C89 due to differences in scope flags.
1353 if (Cond && !getLangOpts().C99 && !getLangOpts().CPlusPlus &&
1354 !Diags.isIgnored(diag::warn_comma_operator, Cond->getExprLoc()))
1355 CommaVisitor(*this).Visit(Cond);
1357 return new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen);
1361 // Use SetVector since the diagnostic cares about the ordering of the Decl's.
1362 using DeclSetVector =
1363 llvm::SetVector<VarDecl *, llvm::SmallVector<VarDecl *, 8>,
1364 llvm::SmallPtrSet<VarDecl *, 8>>;
1366 // This visitor will traverse a conditional statement and store all
1367 // the evaluated decls into a vector. Simple is set to true if none
1368 // of the excluded constructs are used.
1369 class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> {
1370 DeclSetVector &Decls;
1371 SmallVectorImpl<SourceRange> &Ranges;
1374 typedef EvaluatedExprVisitor<DeclExtractor> Inherited;
1376 DeclExtractor(Sema &S, DeclSetVector &Decls,
1377 SmallVectorImpl<SourceRange> &Ranges) :
1378 Inherited(S.Context),
1383 bool isSimple() { return Simple; }
1385 // Replaces the method in EvaluatedExprVisitor.
1386 void VisitMemberExpr(MemberExpr* E) {
1390 // Any Stmt not whitelisted will cause the condition to be marked complex.
1391 void VisitStmt(Stmt *S) {
1395 void VisitBinaryOperator(BinaryOperator *E) {
1400 void VisitCastExpr(CastExpr *E) {
1401 Visit(E->getSubExpr());
1404 void VisitUnaryOperator(UnaryOperator *E) {
1405 // Skip checking conditionals with derefernces.
1406 if (E->getOpcode() == UO_Deref)
1409 Visit(E->getSubExpr());
1412 void VisitConditionalOperator(ConditionalOperator *E) {
1413 Visit(E->getCond());
1414 Visit(E->getTrueExpr());
1415 Visit(E->getFalseExpr());
1418 void VisitParenExpr(ParenExpr *E) {
1419 Visit(E->getSubExpr());
1422 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) {
1423 Visit(E->getOpaqueValue()->getSourceExpr());
1424 Visit(E->getFalseExpr());
1427 void VisitIntegerLiteral(IntegerLiteral *E) { }
1428 void VisitFloatingLiteral(FloatingLiteral *E) { }
1429 void VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) { }
1430 void VisitCharacterLiteral(CharacterLiteral *E) { }
1431 void VisitGNUNullExpr(GNUNullExpr *E) { }
1432 void VisitImaginaryLiteral(ImaginaryLiteral *E) { }
1434 void VisitDeclRefExpr(DeclRefExpr *E) {
1435 VarDecl *VD = dyn_cast<VarDecl>(E->getDecl());
1437 // Don't allow unhandled Decl types.
1442 Ranges.push_back(E->getSourceRange());
1447 }; // end class DeclExtractor
1449 // DeclMatcher checks to see if the decls are used in a non-evaluated
1451 class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> {
1452 DeclSetVector &Decls;
1456 typedef EvaluatedExprVisitor<DeclMatcher> Inherited;
1458 DeclMatcher(Sema &S, DeclSetVector &Decls, Stmt *Statement) :
1459 Inherited(S.Context), Decls(Decls), FoundDecl(false) {
1460 if (!Statement) return;
1465 void VisitReturnStmt(ReturnStmt *S) {
1469 void VisitBreakStmt(BreakStmt *S) {
1473 void VisitGotoStmt(GotoStmt *S) {
1477 void VisitCastExpr(CastExpr *E) {
1478 if (E->getCastKind() == CK_LValueToRValue)
1479 CheckLValueToRValueCast(E->getSubExpr());
1481 Visit(E->getSubExpr());
1484 void CheckLValueToRValueCast(Expr *E) {
1485 E = E->IgnoreParenImpCasts();
1487 if (isa<DeclRefExpr>(E)) {
1491 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
1492 Visit(CO->getCond());
1493 CheckLValueToRValueCast(CO->getTrueExpr());
1494 CheckLValueToRValueCast(CO->getFalseExpr());
1498 if (BinaryConditionalOperator *BCO =
1499 dyn_cast<BinaryConditionalOperator>(E)) {
1500 CheckLValueToRValueCast(BCO->getOpaqueValue()->getSourceExpr());
1501 CheckLValueToRValueCast(BCO->getFalseExpr());
1508 void VisitDeclRefExpr(DeclRefExpr *E) {
1509 if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()))
1510 if (Decls.count(VD))
1514 void VisitPseudoObjectExpr(PseudoObjectExpr *POE) {
1515 // Only need to visit the semantics for POE.
1516 // SyntaticForm doesn't really use the Decal.
1517 for (auto *S : POE->semantics()) {
1518 if (auto *OVE = dyn_cast<OpaqueValueExpr>(S))
1519 // Look past the OVE into the expression it binds.
1520 Visit(OVE->getSourceExpr());
1526 bool FoundDeclInUse() { return FoundDecl; }
1528 }; // end class DeclMatcher
1530 void CheckForLoopConditionalStatement(Sema &S, Expr *Second,
1531 Expr *Third, Stmt *Body) {
1532 // Condition is empty
1533 if (!Second) return;
1535 if (S.Diags.isIgnored(diag::warn_variables_not_in_loop_body,
1536 Second->getBeginLoc()))
1539 PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body);
1540 DeclSetVector Decls;
1541 SmallVector<SourceRange, 10> Ranges;
1542 DeclExtractor DE(S, Decls, Ranges);
1545 // Don't analyze complex conditionals.
1546 if (!DE.isSimple()) return;
1549 if (Decls.size() == 0) return;
1551 // Don't warn on volatile, static, or global variables.
1552 for (auto *VD : Decls)
1553 if (VD->getType().isVolatileQualified() || VD->hasGlobalStorage())
1556 if (DeclMatcher(S, Decls, Second).FoundDeclInUse() ||
1557 DeclMatcher(S, Decls, Third).FoundDeclInUse() ||
1558 DeclMatcher(S, Decls, Body).FoundDeclInUse())
1561 // Load decl names into diagnostic.
1562 if (Decls.size() > 4) {
1565 PDiag << (unsigned)Decls.size();
1566 for (auto *VD : Decls)
1567 PDiag << VD->getDeclName();
1570 for (auto Range : Ranges)
1573 S.Diag(Ranges.begin()->getBegin(), PDiag);
1576 // If Statement is an incemement or decrement, return true and sets the
1577 // variables Increment and DRE.
1578 bool ProcessIterationStmt(Sema &S, Stmt* Statement, bool &Increment,
1579 DeclRefExpr *&DRE) {
1580 if (auto Cleanups = dyn_cast<ExprWithCleanups>(Statement))
1581 if (!Cleanups->cleanupsHaveSideEffects())
1582 Statement = Cleanups->getSubExpr();
1584 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(Statement)) {
1585 switch (UO->getOpcode()) {
1586 default: return false;
1596 DRE = dyn_cast<DeclRefExpr>(UO->getSubExpr());
1600 if (CXXOperatorCallExpr *Call = dyn_cast<CXXOperatorCallExpr>(Statement)) {
1601 FunctionDecl *FD = Call->getDirectCallee();
1602 if (!FD || !FD->isOverloadedOperator()) return false;
1603 switch (FD->getOverloadedOperator()) {
1604 default: return false;
1612 DRE = dyn_cast<DeclRefExpr>(Call->getArg(0));
1619 // A visitor to determine if a continue or break statement is a
1621 class BreakContinueFinder : public ConstEvaluatedExprVisitor<BreakContinueFinder> {
1622 SourceLocation BreakLoc;
1623 SourceLocation ContinueLoc;
1624 bool InSwitch = false;
1627 BreakContinueFinder(Sema &S, const Stmt* Body) :
1628 Inherited(S.Context) {
1632 typedef ConstEvaluatedExprVisitor<BreakContinueFinder> Inherited;
1634 void VisitContinueStmt(const ContinueStmt* E) {
1635 ContinueLoc = E->getContinueLoc();
1638 void VisitBreakStmt(const BreakStmt* E) {
1640 BreakLoc = E->getBreakLoc();
1643 void VisitSwitchStmt(const SwitchStmt* S) {
1644 if (const Stmt *Init = S->getInit())
1646 if (const Stmt *CondVar = S->getConditionVariableDeclStmt())
1648 if (const Stmt *Cond = S->getCond())
1651 // Don't return break statements from the body of a switch.
1653 if (const Stmt *Body = S->getBody())
1658 void VisitForStmt(const ForStmt *S) {
1659 // Only visit the init statement of a for loop; the body
1660 // has a different break/continue scope.
1661 if (const Stmt *Init = S->getInit())
1665 void VisitWhileStmt(const WhileStmt *) {
1666 // Do nothing; the children of a while loop have a different
1667 // break/continue scope.
1670 void VisitDoStmt(const DoStmt *) {
1671 // Do nothing; the children of a while loop have a different
1672 // break/continue scope.
1675 void VisitCXXForRangeStmt(const CXXForRangeStmt *S) {
1676 // Only visit the initialization of a for loop; the body
1677 // has a different break/continue scope.
1678 if (const Stmt *Init = S->getInit())
1680 if (const Stmt *Range = S->getRangeStmt())
1682 if (const Stmt *Begin = S->getBeginStmt())
1684 if (const Stmt *End = S->getEndStmt())
1688 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S) {
1689 // Only visit the initialization of a for loop; the body
1690 // has a different break/continue scope.
1691 if (const Stmt *Element = S->getElement())
1693 if (const Stmt *Collection = S->getCollection())
1697 bool ContinueFound() { return ContinueLoc.isValid(); }
1698 bool BreakFound() { return BreakLoc.isValid(); }
1699 SourceLocation GetContinueLoc() { return ContinueLoc; }
1700 SourceLocation GetBreakLoc() { return BreakLoc; }
1702 }; // end class BreakContinueFinder
1704 // Emit a warning when a loop increment/decrement appears twice per loop
1705 // iteration. The conditions which trigger this warning are:
1706 // 1) The last statement in the loop body and the third expression in the
1707 // for loop are both increment or both decrement of the same variable
1708 // 2) No continue statements in the loop body.
1709 void CheckForRedundantIteration(Sema &S, Expr *Third, Stmt *Body) {
1710 // Return when there is nothing to check.
1711 if (!Body || !Third) return;
1713 if (S.Diags.isIgnored(diag::warn_redundant_loop_iteration,
1714 Third->getBeginLoc()))
1717 // Get the last statement from the loop body.
1718 CompoundStmt *CS = dyn_cast<CompoundStmt>(Body);
1719 if (!CS || CS->body_empty()) return;
1720 Stmt *LastStmt = CS->body_back();
1721 if (!LastStmt) return;
1723 bool LoopIncrement, LastIncrement;
1724 DeclRefExpr *LoopDRE, *LastDRE;
1726 if (!ProcessIterationStmt(S, Third, LoopIncrement, LoopDRE)) return;
1727 if (!ProcessIterationStmt(S, LastStmt, LastIncrement, LastDRE)) return;
1729 // Check that the two statements are both increments or both decrements
1730 // on the same variable.
1731 if (LoopIncrement != LastIncrement ||
1732 LoopDRE->getDecl() != LastDRE->getDecl()) return;
1734 if (BreakContinueFinder(S, Body).ContinueFound()) return;
1736 S.Diag(LastDRE->getLocation(), diag::warn_redundant_loop_iteration)
1737 << LastDRE->getDecl() << LastIncrement;
1738 S.Diag(LoopDRE->getLocation(), diag::note_loop_iteration_here)
1745 void Sema::CheckBreakContinueBinding(Expr *E) {
1746 if (!E || getLangOpts().CPlusPlus)
1748 BreakContinueFinder BCFinder(*this, E);
1749 Scope *BreakParent = CurScope->getBreakParent();
1750 if (BCFinder.BreakFound() && BreakParent) {
1751 if (BreakParent->getFlags() & Scope::SwitchScope) {
1752 Diag(BCFinder.GetBreakLoc(), diag::warn_break_binds_to_switch);
1754 Diag(BCFinder.GetBreakLoc(), diag::warn_loop_ctrl_binds_to_inner)
1757 } else if (BCFinder.ContinueFound() && CurScope->getContinueParent()) {
1758 Diag(BCFinder.GetContinueLoc(), diag::warn_loop_ctrl_binds_to_inner)
1763 StmtResult Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
1764 Stmt *First, ConditionResult Second,
1765 FullExprArg third, SourceLocation RParenLoc,
1767 if (Second.isInvalid())
1770 if (!getLangOpts().CPlusPlus) {
1771 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) {
1772 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
1773 // declare identifiers for objects having storage class 'auto' or
1775 for (auto *DI : DS->decls()) {
1776 VarDecl *VD = dyn_cast<VarDecl>(DI);
1777 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage())
1780 Diag(DI->getLocation(), diag::err_non_local_variable_decl_in_for);
1781 DI->setInvalidDecl();
1787 CheckBreakContinueBinding(Second.get().second);
1788 CheckBreakContinueBinding(third.get());
1790 if (!Second.get().first)
1791 CheckForLoopConditionalStatement(*this, Second.get().second, third.get(),
1793 CheckForRedundantIteration(*this, third.get(), Body);
1795 if (Second.get().second &&
1796 !Diags.isIgnored(diag::warn_comma_operator,
1797 Second.get().second->getExprLoc()))
1798 CommaVisitor(*this).Visit(Second.get().second);
1800 Expr *Third = third.release().getAs<Expr>();
1801 if (isa<NullStmt>(Body))
1802 getCurCompoundScope().setHasEmptyLoopBodies();
1804 return new (Context)
1805 ForStmt(Context, First, Second.get().second, Second.get().first, Third,
1806 Body, ForLoc, LParenLoc, RParenLoc);
1809 /// In an Objective C collection iteration statement:
1811 /// x can be an arbitrary l-value expression. Bind it up as a
1812 /// full-expression.
1813 StmtResult Sema::ActOnForEachLValueExpr(Expr *E) {
1814 // Reduce placeholder expressions here. Note that this rejects the
1815 // use of pseudo-object l-values in this position.
1816 ExprResult result = CheckPlaceholderExpr(E);
1817 if (result.isInvalid()) return StmtError();
1820 ExprResult FullExpr = ActOnFinishFullExpr(E, /*DiscardedValue*/ false);
1821 if (FullExpr.isInvalid())
1823 return StmtResult(static_cast<Stmt*>(FullExpr.get()));
1827 Sema::CheckObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) {
1831 ExprResult result = CorrectDelayedTyposInExpr(collection);
1832 if (!result.isUsable())
1834 collection = result.get();
1836 // Bail out early if we've got a type-dependent expression.
1837 if (collection->isTypeDependent()) return collection;
1839 // Perform normal l-value conversion.
1840 result = DefaultFunctionArrayLvalueConversion(collection);
1841 if (result.isInvalid())
1843 collection = result.get();
1845 // The operand needs to have object-pointer type.
1846 // TODO: should we do a contextual conversion?
1847 const ObjCObjectPointerType *pointerType =
1848 collection->getType()->getAs<ObjCObjectPointerType>();
1850 return Diag(forLoc, diag::err_collection_expr_type)
1851 << collection->getType() << collection->getSourceRange();
1853 // Check that the operand provides
1854 // - countByEnumeratingWithState:objects:count:
1855 const ObjCObjectType *objectType = pointerType->getObjectType();
1856 ObjCInterfaceDecl *iface = objectType->getInterface();
1858 // If we have a forward-declared type, we can't do this check.
1859 // Under ARC, it is an error not to have a forward-declared class.
1861 (getLangOpts().ObjCAutoRefCount
1862 ? RequireCompleteType(forLoc, QualType(objectType, 0),
1863 diag::err_arc_collection_forward, collection)
1864 : !isCompleteType(forLoc, QualType(objectType, 0)))) {
1865 // Otherwise, if we have any useful type information, check that
1866 // the type declares the appropriate method.
1867 } else if (iface || !objectType->qual_empty()) {
1868 IdentifierInfo *selectorIdents[] = {
1869 &Context.Idents.get("countByEnumeratingWithState"),
1870 &Context.Idents.get("objects"),
1871 &Context.Idents.get("count")
1873 Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]);
1875 ObjCMethodDecl *method = nullptr;
1877 // If there's an interface, look in both the public and private APIs.
1879 method = iface->lookupInstanceMethod(selector);
1880 if (!method) method = iface->lookupPrivateMethod(selector);
1883 // Also check protocol qualifiers.
1885 method = LookupMethodInQualifiedType(selector, pointerType,
1888 // If we didn't find it anywhere, give up.
1890 Diag(forLoc, diag::warn_collection_expr_type)
1891 << collection->getType() << selector << collection->getSourceRange();
1894 // TODO: check for an incompatible signature?
1897 // Wrap up any cleanups in the expression.
1902 Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc,
1903 Stmt *First, Expr *collection,
1904 SourceLocation RParenLoc) {
1905 setFunctionHasBranchProtectedScope();
1907 ExprResult CollectionExprResult =
1908 CheckObjCForCollectionOperand(ForLoc, collection);
1912 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) {
1913 if (!DS->isSingleDecl())
1914 return StmtError(Diag((*DS->decl_begin())->getLocation(),
1915 diag::err_toomany_element_decls));
1917 VarDecl *D = dyn_cast<VarDecl>(DS->getSingleDecl());
1918 if (!D || D->isInvalidDecl())
1921 FirstType = D->getType();
1922 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
1923 // declare identifiers for objects having storage class 'auto' or
1925 if (!D->hasLocalStorage())
1926 return StmtError(Diag(D->getLocation(),
1927 diag::err_non_local_variable_decl_in_for));
1929 // If the type contained 'auto', deduce the 'auto' to 'id'.
1930 if (FirstType->getContainedAutoType()) {
1931 OpaqueValueExpr OpaqueId(D->getLocation(), Context.getObjCIdType(),
1933 Expr *DeducedInit = &OpaqueId;
1934 if (DeduceAutoType(D->getTypeSourceInfo(), DeducedInit, FirstType) ==
1936 DiagnoseAutoDeductionFailure(D, DeducedInit);
1937 if (FirstType.isNull()) {
1938 D->setInvalidDecl();
1942 D->setType(FirstType);
1944 if (!inTemplateInstantiation()) {
1945 SourceLocation Loc =
1946 D->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
1947 Diag(Loc, diag::warn_auto_var_is_id)
1948 << D->getDeclName();
1953 Expr *FirstE = cast<Expr>(First);
1954 if (!FirstE->isTypeDependent() && !FirstE->isLValue())
1956 Diag(First->getBeginLoc(), diag::err_selector_element_not_lvalue)
1957 << First->getSourceRange());
1959 FirstType = static_cast<Expr*>(First)->getType();
1960 if (FirstType.isConstQualified())
1961 Diag(ForLoc, diag::err_selector_element_const_type)
1962 << FirstType << First->getSourceRange();
1964 if (!FirstType->isDependentType() &&
1965 !FirstType->isObjCObjectPointerType() &&
1966 !FirstType->isBlockPointerType())
1967 return StmtError(Diag(ForLoc, diag::err_selector_element_type)
1968 << FirstType << First->getSourceRange());
1971 if (CollectionExprResult.isInvalid())
1974 CollectionExprResult =
1975 ActOnFinishFullExpr(CollectionExprResult.get(), /*DiscardedValue*/ false);
1976 if (CollectionExprResult.isInvalid())
1979 return new (Context) ObjCForCollectionStmt(First, CollectionExprResult.get(),
1980 nullptr, ForLoc, RParenLoc);
1983 /// Finish building a variable declaration for a for-range statement.
1984 /// \return true if an error occurs.
1985 static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init,
1986 SourceLocation Loc, int DiagID) {
1987 if (Decl->getType()->isUndeducedType()) {
1988 ExprResult Res = SemaRef.CorrectDelayedTyposInExpr(Init);
1989 if (!Res.isUsable()) {
1990 Decl->setInvalidDecl();
1996 // Deduce the type for the iterator variable now rather than leaving it to
1997 // AddInitializerToDecl, so we can produce a more suitable diagnostic.
1999 if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) ||
2000 SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitType) ==
2002 SemaRef.Diag(Loc, DiagID) << Init->getType();
2003 if (InitType.isNull()) {
2004 Decl->setInvalidDecl();
2007 Decl->setType(InitType);
2009 // In ARC, infer lifetime.
2010 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if
2011 // we're doing the equivalent of fast iteration.
2012 if (SemaRef.getLangOpts().ObjCAutoRefCount &&
2013 SemaRef.inferObjCARCLifetime(Decl))
2014 Decl->setInvalidDecl();
2016 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false);
2017 SemaRef.FinalizeDeclaration(Decl);
2018 SemaRef.CurContext->addHiddenDecl(Decl);
2023 // An enum to represent whether something is dealing with a call to begin()
2024 // or a call to end() in a range-based for loop.
2025 enum BeginEndFunction {
2030 /// Produce a note indicating which begin/end function was implicitly called
2031 /// by a C++11 for-range statement. This is often not obvious from the code,
2032 /// nor from the diagnostics produced when analysing the implicit expressions
2033 /// required in a for-range statement.
2034 void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E,
2035 BeginEndFunction BEF) {
2036 CallExpr *CE = dyn_cast<CallExpr>(E);
2039 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl());
2042 SourceLocation Loc = D->getLocation();
2044 std::string Description;
2045 bool IsTemplate = false;
2046 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) {
2047 Description = SemaRef.getTemplateArgumentBindingsText(
2048 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs());
2052 SemaRef.Diag(Loc, diag::note_for_range_begin_end)
2053 << BEF << IsTemplate << Description << E->getType();
2056 /// Build a variable declaration for a for-range statement.
2057 VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc,
2058 QualType Type, StringRef Name) {
2059 DeclContext *DC = SemaRef.CurContext;
2060 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name);
2061 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc);
2062 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type,
2064 Decl->setImplicit();
2070 static bool ObjCEnumerationCollection(Expr *Collection) {
2071 return !Collection->isTypeDependent()
2072 && Collection->getType()->getAs<ObjCObjectPointerType>() != nullptr;
2075 /// ActOnCXXForRangeStmt - Check and build a C++11 for-range statement.
2077 /// C++11 [stmt.ranged]:
2078 /// A range-based for statement is equivalent to
2081 /// auto && __range = range-init;
2082 /// for ( auto __begin = begin-expr,
2083 /// __end = end-expr;
2084 /// __begin != __end;
2086 /// for-range-declaration = *__begin;
2091 /// The body of the loop is not available yet, since it cannot be analysed until
2092 /// we have determined the type of the for-range-declaration.
2093 StmtResult Sema::ActOnCXXForRangeStmt(Scope *S, SourceLocation ForLoc,
2094 SourceLocation CoawaitLoc, Stmt *InitStmt,
2095 Stmt *First, SourceLocation ColonLoc,
2096 Expr *Range, SourceLocation RParenLoc,
2097 BuildForRangeKind Kind) {
2101 if (Range && ObjCEnumerationCollection(Range)) {
2102 // FIXME: Support init-statements in Objective-C++20 ranged for statement.
2104 return Diag(InitStmt->getBeginLoc(), diag::err_objc_for_range_init_stmt)
2105 << InitStmt->getSourceRange();
2106 return ActOnObjCForCollectionStmt(ForLoc, First, Range, RParenLoc);
2109 DeclStmt *DS = dyn_cast<DeclStmt>(First);
2110 assert(DS && "first part of for range not a decl stmt");
2112 if (!DS->isSingleDecl()) {
2113 Diag(DS->getBeginLoc(), diag::err_type_defined_in_for_range);
2117 Decl *LoopVar = DS->getSingleDecl();
2118 if (LoopVar->isInvalidDecl() || !Range ||
2119 DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) {
2120 LoopVar->setInvalidDecl();
2124 // Build the coroutine state immediately and not later during template
2126 if (!CoawaitLoc.isInvalid()) {
2127 if (!ActOnCoroutineBodyStart(S, CoawaitLoc, "co_await"))
2131 // Build auto && __range = range-init
2132 // Divide by 2, since the variables are in the inner scope (loop body).
2133 const auto DepthStr = std::to_string(S->getDepth() / 2);
2134 SourceLocation RangeLoc = Range->getBeginLoc();
2135 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc,
2136 Context.getAutoRRefDeductType(),
2137 std::string("__range") + DepthStr);
2138 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc,
2139 diag::err_for_range_deduction_failure)) {
2140 LoopVar->setInvalidDecl();
2144 // Claim the type doesn't contain auto: we've already done the checking.
2145 DeclGroupPtrTy RangeGroup =
2146 BuildDeclaratorGroup(MutableArrayRef<Decl *>((Decl **)&RangeVar, 1));
2147 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc);
2148 if (RangeDecl.isInvalid()) {
2149 LoopVar->setInvalidDecl();
2153 return BuildCXXForRangeStmt(
2154 ForLoc, CoawaitLoc, InitStmt, ColonLoc, RangeDecl.get(),
2155 /*BeginStmt=*/nullptr, /*EndStmt=*/nullptr,
2156 /*Cond=*/nullptr, /*Inc=*/nullptr, DS, RParenLoc, Kind);
2159 /// Create the initialization, compare, and increment steps for
2160 /// the range-based for loop expression.
2161 /// This function does not handle array-based for loops,
2162 /// which are created in Sema::BuildCXXForRangeStmt.
2164 /// \returns a ForRangeStatus indicating success or what kind of error occurred.
2165 /// BeginExpr and EndExpr are set and FRS_Success is returned on success;
2166 /// CandidateSet and BEF are set and some non-success value is returned on
2168 static Sema::ForRangeStatus
2169 BuildNonArrayForRange(Sema &SemaRef, Expr *BeginRange, Expr *EndRange,
2170 QualType RangeType, VarDecl *BeginVar, VarDecl *EndVar,
2171 SourceLocation ColonLoc, SourceLocation CoawaitLoc,
2172 OverloadCandidateSet *CandidateSet, ExprResult *BeginExpr,
2173 ExprResult *EndExpr, BeginEndFunction *BEF) {
2174 DeclarationNameInfo BeginNameInfo(
2175 &SemaRef.PP.getIdentifierTable().get("begin"), ColonLoc);
2176 DeclarationNameInfo EndNameInfo(&SemaRef.PP.getIdentifierTable().get("end"),
2179 LookupResult BeginMemberLookup(SemaRef, BeginNameInfo,
2180 Sema::LookupMemberName);
2181 LookupResult EndMemberLookup(SemaRef, EndNameInfo, Sema::LookupMemberName);
2183 auto BuildBegin = [&] {
2185 Sema::ForRangeStatus RangeStatus =
2186 SemaRef.BuildForRangeBeginEndCall(ColonLoc, ColonLoc, BeginNameInfo,
2187 BeginMemberLookup, CandidateSet,
2188 BeginRange, BeginExpr);
2190 if (RangeStatus != Sema::FRS_Success) {
2191 if (RangeStatus == Sema::FRS_DiagnosticIssued)
2192 SemaRef.Diag(BeginRange->getBeginLoc(), diag::note_in_for_range)
2193 << ColonLoc << BEF_begin << BeginRange->getType();
2196 if (!CoawaitLoc.isInvalid()) {
2197 // FIXME: getCurScope() should not be used during template instantiation.
2198 // We should pick up the set of unqualified lookup results for operator
2199 // co_await during the initial parse.
2200 *BeginExpr = SemaRef.ActOnCoawaitExpr(SemaRef.getCurScope(), ColonLoc,
2202 if (BeginExpr->isInvalid())
2203 return Sema::FRS_DiagnosticIssued;
2205 if (FinishForRangeVarDecl(SemaRef, BeginVar, BeginExpr->get(), ColonLoc,
2206 diag::err_for_range_iter_deduction_failure)) {
2207 NoteForRangeBeginEndFunction(SemaRef, BeginExpr->get(), *BEF);
2208 return Sema::FRS_DiagnosticIssued;
2210 return Sema::FRS_Success;
2213 auto BuildEnd = [&] {
2215 Sema::ForRangeStatus RangeStatus =
2216 SemaRef.BuildForRangeBeginEndCall(ColonLoc, ColonLoc, EndNameInfo,
2217 EndMemberLookup, CandidateSet,
2219 if (RangeStatus != Sema::FRS_Success) {
2220 if (RangeStatus == Sema::FRS_DiagnosticIssued)
2221 SemaRef.Diag(EndRange->getBeginLoc(), diag::note_in_for_range)
2222 << ColonLoc << BEF_end << EndRange->getType();
2225 if (FinishForRangeVarDecl(SemaRef, EndVar, EndExpr->get(), ColonLoc,
2226 diag::err_for_range_iter_deduction_failure)) {
2227 NoteForRangeBeginEndFunction(SemaRef, EndExpr->get(), *BEF);
2228 return Sema::FRS_DiagnosticIssued;
2230 return Sema::FRS_Success;
2233 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) {
2234 // - if _RangeT is a class type, the unqualified-ids begin and end are
2235 // looked up in the scope of class _RangeT as if by class member access
2236 // lookup (3.4.5), and if either (or both) finds at least one
2237 // declaration, begin-expr and end-expr are __range.begin() and
2238 // __range.end(), respectively;
2239 SemaRef.LookupQualifiedName(BeginMemberLookup, D);
2240 if (BeginMemberLookup.isAmbiguous())
2241 return Sema::FRS_DiagnosticIssued;
2243 SemaRef.LookupQualifiedName(EndMemberLookup, D);
2244 if (EndMemberLookup.isAmbiguous())
2245 return Sema::FRS_DiagnosticIssued;
2247 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) {
2248 // Look up the non-member form of the member we didn't find, first.
2249 // This way we prefer a "no viable 'end'" diagnostic over a "i found
2250 // a 'begin' but ignored it because there was no member 'end'"
2252 auto BuildNonmember = [&](
2253 BeginEndFunction BEFFound, LookupResult &Found,
2254 llvm::function_ref<Sema::ForRangeStatus()> BuildFound,
2255 llvm::function_ref<Sema::ForRangeStatus()> BuildNotFound) {
2256 LookupResult OldFound = std::move(Found);
2259 if (Sema::ForRangeStatus Result = BuildNotFound())
2262 switch (BuildFound()) {
2263 case Sema::FRS_Success:
2264 return Sema::FRS_Success;
2266 case Sema::FRS_NoViableFunction:
2267 CandidateSet->NoteCandidates(
2268 PartialDiagnosticAt(BeginRange->getBeginLoc(),
2269 SemaRef.PDiag(diag::err_for_range_invalid)
2270 << BeginRange->getType() << BEFFound),
2271 SemaRef, OCD_AllCandidates, BeginRange);
2274 case Sema::FRS_DiagnosticIssued:
2275 for (NamedDecl *D : OldFound) {
2276 SemaRef.Diag(D->getLocation(),
2277 diag::note_for_range_member_begin_end_ignored)
2278 << BeginRange->getType() << BEFFound;
2280 return Sema::FRS_DiagnosticIssued;
2282 llvm_unreachable("unexpected ForRangeStatus");
2284 if (BeginMemberLookup.empty())
2285 return BuildNonmember(BEF_end, EndMemberLookup, BuildEnd, BuildBegin);
2286 return BuildNonmember(BEF_begin, BeginMemberLookup, BuildBegin, BuildEnd);
2289 // - otherwise, begin-expr and end-expr are begin(__range) and
2290 // end(__range), respectively, where begin and end are looked up with
2291 // argument-dependent lookup (3.4.2). For the purposes of this name
2292 // lookup, namespace std is an associated namespace.
2295 if (Sema::ForRangeStatus Result = BuildBegin())
2300 /// Speculatively attempt to dereference an invalid range expression.
2301 /// If the attempt fails, this function will return a valid, null StmtResult
2302 /// and emit no diagnostics.
2303 static StmtResult RebuildForRangeWithDereference(Sema &SemaRef, Scope *S,
2304 SourceLocation ForLoc,
2305 SourceLocation CoawaitLoc,
2308 SourceLocation ColonLoc,
2310 SourceLocation RangeLoc,
2311 SourceLocation RParenLoc) {
2312 // Determine whether we can rebuild the for-range statement with a
2313 // dereferenced range expression.
2314 ExprResult AdjustedRange;
2316 Sema::SFINAETrap Trap(SemaRef);
2318 AdjustedRange = SemaRef.BuildUnaryOp(S, RangeLoc, UO_Deref, Range);
2319 if (AdjustedRange.isInvalid())
2320 return StmtResult();
2322 StmtResult SR = SemaRef.ActOnCXXForRangeStmt(
2323 S, ForLoc, CoawaitLoc, InitStmt, LoopVarDecl, ColonLoc,
2324 AdjustedRange.get(), RParenLoc, Sema::BFRK_Check);
2326 return StmtResult();
2329 // The attempt to dereference worked well enough that it could produce a valid
2330 // loop. Produce a fixit, and rebuild the loop with diagnostics enabled, in
2331 // case there are any other (non-fatal) problems with it.
2332 SemaRef.Diag(RangeLoc, diag::err_for_range_dereference)
2333 << Range->getType() << FixItHint::CreateInsertion(RangeLoc, "*");
2334 return SemaRef.ActOnCXXForRangeStmt(
2335 S, ForLoc, CoawaitLoc, InitStmt, LoopVarDecl, ColonLoc,
2336 AdjustedRange.get(), RParenLoc, Sema::BFRK_Rebuild);
2340 /// RAII object to automatically invalidate a declaration if an error occurs.
2341 struct InvalidateOnErrorScope {
2342 InvalidateOnErrorScope(Sema &SemaRef, Decl *D, bool Enabled)
2343 : Trap(SemaRef.Diags), D(D), Enabled(Enabled) {}
2344 ~InvalidateOnErrorScope() {
2345 if (Enabled && Trap.hasErrorOccurred())
2346 D->setInvalidDecl();
2349 DiagnosticErrorTrap Trap;
2355 /// BuildCXXForRangeStmt - Build or instantiate a C++11 for-range statement.
2356 StmtResult Sema::BuildCXXForRangeStmt(SourceLocation ForLoc,
2357 SourceLocation CoawaitLoc, Stmt *InitStmt,
2358 SourceLocation ColonLoc, Stmt *RangeDecl,
2359 Stmt *Begin, Stmt *End, Expr *Cond,
2360 Expr *Inc, Stmt *LoopVarDecl,
2361 SourceLocation RParenLoc,
2362 BuildForRangeKind Kind) {
2363 // FIXME: This should not be used during template instantiation. We should
2364 // pick up the set of unqualified lookup results for the != and + operators
2365 // in the initial parse.
2367 // Testcase (accepts-invalid):
2368 // template<typename T> void f() { for (auto x : T()) {} }
2369 // namespace N { struct X { X begin(); X end(); int operator*(); }; }
2370 // bool operator!=(N::X, N::X); void operator++(N::X);
2371 // void g() { f<N::X>(); }
2372 Scope *S = getCurScope();
2374 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl);
2375 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl());
2376 QualType RangeVarType = RangeVar->getType();
2378 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl);
2379 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl());
2381 // If we hit any errors, mark the loop variable as invalid if its type
2383 InvalidateOnErrorScope Invalidate(*this, LoopVar,
2384 LoopVar->getType()->isUndeducedType());
2386 StmtResult BeginDeclStmt = Begin;
2387 StmtResult EndDeclStmt = End;
2388 ExprResult NotEqExpr = Cond, IncrExpr = Inc;
2390 if (RangeVarType->isDependentType()) {
2391 // The range is implicitly used as a placeholder when it is dependent.
2392 RangeVar->markUsed(Context);
2394 // Deduce any 'auto's in the loop variable as 'DependentTy'. We'll fill
2395 // them in properly when we instantiate the loop.
2396 if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) {
2397 if (auto *DD = dyn_cast<DecompositionDecl>(LoopVar))
2398 for (auto *Binding : DD->bindings())
2399 Binding->setType(Context.DependentTy);
2400 LoopVar->setType(SubstAutoType(LoopVar->getType(), Context.DependentTy));
2402 } else if (!BeginDeclStmt.get()) {
2403 SourceLocation RangeLoc = RangeVar->getLocation();
2405 const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType();
2407 ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType,
2408 VK_LValue, ColonLoc);
2409 if (BeginRangeRef.isInvalid())
2412 ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType,
2413 VK_LValue, ColonLoc);
2414 if (EndRangeRef.isInvalid())
2417 QualType AutoType = Context.getAutoDeductType();
2418 Expr *Range = RangeVar->getInit();
2421 QualType RangeType = Range->getType();
2423 if (RequireCompleteType(RangeLoc, RangeType,
2424 diag::err_for_range_incomplete_type))
2427 // Build auto __begin = begin-expr, __end = end-expr.
2428 // Divide by 2, since the variables are in the inner scope (loop body).
2429 const auto DepthStr = std::to_string(S->getDepth() / 2);
2430 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType,
2431 std::string("__begin") + DepthStr);
2432 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType,
2433 std::string("__end") + DepthStr);
2435 // Build begin-expr and end-expr and attach to __begin and __end variables.
2436 ExprResult BeginExpr, EndExpr;
2437 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) {
2438 // - if _RangeT is an array type, begin-expr and end-expr are __range and
2439 // __range + __bound, respectively, where __bound is the array bound. If
2440 // _RangeT is an array of unknown size or an array of incomplete type,
2441 // the program is ill-formed;
2443 // begin-expr is __range.
2444 BeginExpr = BeginRangeRef;
2445 if (!CoawaitLoc.isInvalid()) {
2446 BeginExpr = ActOnCoawaitExpr(S, ColonLoc, BeginExpr.get());
2447 if (BeginExpr.isInvalid())
2450 if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc,
2451 diag::err_for_range_iter_deduction_failure)) {
2452 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2456 // Find the array bound.
2457 ExprResult BoundExpr;
2458 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT))
2459 BoundExpr = IntegerLiteral::Create(
2460 Context, CAT->getSize(), Context.getPointerDiffType(), RangeLoc);
2461 else if (const VariableArrayType *VAT =
2462 dyn_cast<VariableArrayType>(UnqAT)) {
2463 // For a variably modified type we can't just use the expression within
2464 // the array bounds, since we don't want that to be re-evaluated here.
2465 // Rather, we need to determine what it was when the array was first
2466 // created - so we resort to using sizeof(vla)/sizeof(element).
2470 // b = -1; <-- This should not affect the num of iterations below
2471 // for (int &c : vla) { .. }
2474 // FIXME: This results in codegen generating IR that recalculates the
2475 // run-time number of elements (as opposed to just using the IR Value
2476 // that corresponds to the run-time value of each bound that was
2477 // generated when the array was created.) If this proves too embarrassing
2478 // even for unoptimized IR, consider passing a magic-value/cookie to
2479 // codegen that then knows to simply use that initial llvm::Value (that
2480 // corresponds to the bound at time of array creation) within
2481 // getelementptr. But be prepared to pay the price of increasing a
2482 // customized form of coupling between the two components - which could
2483 // be hard to maintain as the codebase evolves.
2485 ExprResult SizeOfVLAExprR = ActOnUnaryExprOrTypeTraitExpr(
2486 EndVar->getLocation(), UETT_SizeOf,
2488 CreateParsedType(VAT->desugar(), Context.getTrivialTypeSourceInfo(
2489 VAT->desugar(), RangeLoc))
2491 EndVar->getSourceRange());
2492 if (SizeOfVLAExprR.isInvalid())
2495 ExprResult SizeOfEachElementExprR = ActOnUnaryExprOrTypeTraitExpr(
2496 EndVar->getLocation(), UETT_SizeOf,
2498 CreateParsedType(VAT->desugar(),
2499 Context.getTrivialTypeSourceInfo(
2500 VAT->getElementType(), RangeLoc))
2502 EndVar->getSourceRange());
2503 if (SizeOfEachElementExprR.isInvalid())
2507 ActOnBinOp(S, EndVar->getLocation(), tok::slash,
2508 SizeOfVLAExprR.get(), SizeOfEachElementExprR.get());
2509 if (BoundExpr.isInvalid())
2513 // Can't be a DependentSizedArrayType or an IncompleteArrayType since
2514 // UnqAT is not incomplete and Range is not type-dependent.
2515 llvm_unreachable("Unexpected array type in for-range");
2518 // end-expr is __range + __bound.
2519 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(),
2521 if (EndExpr.isInvalid())
2523 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc,
2524 diag::err_for_range_iter_deduction_failure)) {
2525 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
2529 OverloadCandidateSet CandidateSet(RangeLoc,
2530 OverloadCandidateSet::CSK_Normal);
2531 BeginEndFunction BEFFailure;
2532 ForRangeStatus RangeStatus = BuildNonArrayForRange(
2533 *this, BeginRangeRef.get(), EndRangeRef.get(), RangeType, BeginVar,
2534 EndVar, ColonLoc, CoawaitLoc, &CandidateSet, &BeginExpr, &EndExpr,
2537 if (Kind == BFRK_Build && RangeStatus == FRS_NoViableFunction &&
2538 BEFFailure == BEF_begin) {
2539 // If the range is being built from an array parameter, emit a
2540 // a diagnostic that it is being treated as a pointer.
2541 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Range)) {
2542 if (ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
2543 QualType ArrayTy = PVD->getOriginalType();
2544 QualType PointerTy = PVD->getType();
2545 if (PointerTy->isPointerType() && ArrayTy->isArrayType()) {
2546 Diag(Range->getBeginLoc(), diag::err_range_on_array_parameter)
2547 << RangeLoc << PVD << ArrayTy << PointerTy;
2548 Diag(PVD->getLocation(), diag::note_declared_at);
2554 // If building the range failed, try dereferencing the range expression
2555 // unless a diagnostic was issued or the end function is problematic.
2556 StmtResult SR = RebuildForRangeWithDereference(*this, S, ForLoc,
2557 CoawaitLoc, InitStmt,
2558 LoopVarDecl, ColonLoc,
2561 if (SR.isInvalid() || SR.isUsable())
2565 // Otherwise, emit diagnostics if we haven't already.
2566 if (RangeStatus == FRS_NoViableFunction) {
2567 Expr *Range = BEFFailure ? EndRangeRef.get() : BeginRangeRef.get();
2568 CandidateSet.NoteCandidates(
2569 PartialDiagnosticAt(Range->getBeginLoc(),
2570 PDiag(diag::err_for_range_invalid)
2571 << RangeLoc << Range->getType()
2573 *this, OCD_AllCandidates, Range);
2575 // Return an error if no fix was discovered.
2576 if (RangeStatus != FRS_Success)
2580 assert(!BeginExpr.isInvalid() && !EndExpr.isInvalid() &&
2581 "invalid range expression in for loop");
2583 // C++11 [dcl.spec.auto]p7: BeginType and EndType must be the same.
2584 // C++1z removes this restriction.
2585 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType();
2586 if (!Context.hasSameType(BeginType, EndType)) {
2587 Diag(RangeLoc, getLangOpts().CPlusPlus17
2588 ? diag::warn_for_range_begin_end_types_differ
2589 : diag::ext_for_range_begin_end_types_differ)
2590 << BeginType << EndType;
2591 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2592 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
2596 ActOnDeclStmt(ConvertDeclToDeclGroup(BeginVar), ColonLoc, ColonLoc);
2598 ActOnDeclStmt(ConvertDeclToDeclGroup(EndVar), ColonLoc, ColonLoc);
2600 const QualType BeginRefNonRefType = BeginType.getNonReferenceType();
2601 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2602 VK_LValue, ColonLoc);
2603 if (BeginRef.isInvalid())
2606 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(),
2607 VK_LValue, ColonLoc);
2608 if (EndRef.isInvalid())
2611 // Build and check __begin != __end expression.
2612 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal,
2613 BeginRef.get(), EndRef.get());
2614 if (!NotEqExpr.isInvalid())
2615 NotEqExpr = CheckBooleanCondition(ColonLoc, NotEqExpr.get());
2616 if (!NotEqExpr.isInvalid())
2618 ActOnFinishFullExpr(NotEqExpr.get(), /*DiscardedValue*/ false);
2619 if (NotEqExpr.isInvalid()) {
2620 Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2621 << RangeLoc << 0 << BeginRangeRef.get()->getType();
2622 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2623 if (!Context.hasSameType(BeginType, EndType))
2624 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
2628 // Build and check ++__begin expression.
2629 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2630 VK_LValue, ColonLoc);
2631 if (BeginRef.isInvalid())
2634 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get());
2635 if (!IncrExpr.isInvalid() && CoawaitLoc.isValid())
2636 // FIXME: getCurScope() should not be used during template instantiation.
2637 // We should pick up the set of unqualified lookup results for operator
2638 // co_await during the initial parse.
2639 IncrExpr = ActOnCoawaitExpr(S, CoawaitLoc, IncrExpr.get());
2640 if (!IncrExpr.isInvalid())
2641 IncrExpr = ActOnFinishFullExpr(IncrExpr.get(), /*DiscardedValue*/ false);
2642 if (IncrExpr.isInvalid()) {
2643 Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2644 << RangeLoc << 2 << BeginRangeRef.get()->getType() ;
2645 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2649 // Build and check *__begin expression.
2650 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2651 VK_LValue, ColonLoc);
2652 if (BeginRef.isInvalid())
2655 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get());
2656 if (DerefExpr.isInvalid()) {
2657 Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2658 << RangeLoc << 1 << BeginRangeRef.get()->getType();
2659 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2663 // Attach *__begin as initializer for VD. Don't touch it if we're just
2664 // trying to determine whether this would be a valid range.
2665 if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) {
2666 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false);
2667 if (LoopVar->isInvalidDecl())
2668 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2672 // Don't bother to actually allocate the result if we're just trying to
2673 // determine whether it would be valid.
2674 if (Kind == BFRK_Check)
2675 return StmtResult();
2677 // In OpenMP loop region loop control variable must be private. Perform
2678 // analysis of first part (if any).
2679 if (getLangOpts().OpenMP >= 50 && BeginDeclStmt.isUsable())
2680 ActOnOpenMPLoopInitialization(ForLoc, BeginDeclStmt.get());
2682 return new (Context) CXXForRangeStmt(
2683 InitStmt, RangeDS, cast_or_null<DeclStmt>(BeginDeclStmt.get()),
2684 cast_or_null<DeclStmt>(EndDeclStmt.get()), NotEqExpr.get(),
2685 IncrExpr.get(), LoopVarDS, /*Body=*/nullptr, ForLoc, CoawaitLoc,
2686 ColonLoc, RParenLoc);
2689 /// FinishObjCForCollectionStmt - Attach the body to a objective-C foreach
2691 StmtResult Sema::FinishObjCForCollectionStmt(Stmt *S, Stmt *B) {
2694 ObjCForCollectionStmt * ForStmt = cast<ObjCForCollectionStmt>(S);
2696 ForStmt->setBody(B);
2700 // Warn when the loop variable is a const reference that creates a copy.
2701 // Suggest using the non-reference type for copies. If a copy can be prevented
2702 // suggest the const reference type that would do so.
2703 // For instance, given "for (const &Foo : Range)", suggest
2704 // "for (const Foo : Range)" to denote a copy is made for the loop. If
2705 // possible, also suggest "for (const &Bar : Range)" if this type prevents
2706 // the copy altogether.
2707 static void DiagnoseForRangeReferenceVariableCopies(Sema &SemaRef,
2709 QualType RangeInitType) {
2710 const Expr *InitExpr = VD->getInit();
2714 QualType VariableType = VD->getType();
2716 if (auto Cleanups = dyn_cast<ExprWithCleanups>(InitExpr))
2717 if (!Cleanups->cleanupsHaveSideEffects())
2718 InitExpr = Cleanups->getSubExpr();
2720 const MaterializeTemporaryExpr *MTE =
2721 dyn_cast<MaterializeTemporaryExpr>(InitExpr);
2727 const Expr *E = MTE->getSubExpr()->IgnoreImpCasts();
2729 // Searching for either UnaryOperator for dereference of a pointer or
2730 // CXXOperatorCallExpr for handling iterators.
2731 while (!isa<CXXOperatorCallExpr>(E) && !isa<UnaryOperator>(E)) {
2732 if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(E)) {
2734 } else if (const CXXMemberCallExpr *Call = dyn_cast<CXXMemberCallExpr>(E)) {
2735 const MemberExpr *ME = cast<MemberExpr>(Call->getCallee());
2738 const MaterializeTemporaryExpr *MTE = cast<MaterializeTemporaryExpr>(E);
2739 E = MTE->getSubExpr();
2741 E = E->IgnoreImpCasts();
2744 bool ReturnsReference = false;
2745 if (isa<UnaryOperator>(E)) {
2746 ReturnsReference = true;
2748 const CXXOperatorCallExpr *Call = cast<CXXOperatorCallExpr>(E);
2749 const FunctionDecl *FD = Call->getDirectCallee();
2750 QualType ReturnType = FD->getReturnType();
2751 ReturnsReference = ReturnType->isReferenceType();
2754 if (ReturnsReference) {
2755 // Loop variable creates a temporary. Suggest either to go with
2756 // non-reference loop variable to indicate a copy is made, or
2757 // the correct time to bind a const reference.
2758 SemaRef.Diag(VD->getLocation(), diag::warn_for_range_const_reference_copy)
2759 << VD << VariableType << E->getType();
2760 QualType NonReferenceType = VariableType.getNonReferenceType();
2761 NonReferenceType.removeLocalConst();
2762 QualType NewReferenceType =
2763 SemaRef.Context.getLValueReferenceType(E->getType().withConst());
2764 SemaRef.Diag(VD->getBeginLoc(), diag::note_use_type_or_non_reference)
2765 << NonReferenceType << NewReferenceType << VD->getSourceRange()
2766 << FixItHint::CreateRemoval(VD->getTypeSpecEndLoc());
2767 } else if (!VariableType->isRValueReferenceType()) {
2768 // The range always returns a copy, so a temporary is always created.
2769 // Suggest removing the reference from the loop variable.
2770 // If the type is a rvalue reference do not warn since that changes the
2771 // semantic of the code.
2772 SemaRef.Diag(VD->getLocation(), diag::warn_for_range_variable_always_copy)
2773 << VD << RangeInitType;
2774 QualType NonReferenceType = VariableType.getNonReferenceType();
2775 NonReferenceType.removeLocalConst();
2776 SemaRef.Diag(VD->getBeginLoc(), diag::note_use_non_reference_type)
2777 << NonReferenceType << VD->getSourceRange()
2778 << FixItHint::CreateRemoval(VD->getTypeSpecEndLoc());
2782 /// Determines whether the @p VariableType's declaration is a record with the
2783 /// clang::trivial_abi attribute.
2784 static bool hasTrivialABIAttr(QualType VariableType) {
2785 if (CXXRecordDecl *RD = VariableType->getAsCXXRecordDecl())
2786 return RD->hasAttr<TrivialABIAttr>();
2791 // Warns when the loop variable can be changed to a reference type to
2792 // prevent a copy. For instance, if given "for (const Foo x : Range)" suggest
2793 // "for (const Foo &x : Range)" if this form does not make a copy.
2794 static void DiagnoseForRangeConstVariableCopies(Sema &SemaRef,
2795 const VarDecl *VD) {
2796 const Expr *InitExpr = VD->getInit();
2800 QualType VariableType = VD->getType();
2802 if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(InitExpr)) {
2803 if (!CE->getConstructor()->isCopyConstructor())
2805 } else if (const CastExpr *CE = dyn_cast<CastExpr>(InitExpr)) {
2806 if (CE->getCastKind() != CK_LValueToRValue)
2812 // Small trivially copyable types are cheap to copy. Do not emit the
2813 // diagnostic for these instances. 64 bytes is a common size of a cache line.
2814 // (The function `getTypeSize` returns the size in bits.)
2815 ASTContext &Ctx = SemaRef.Context;
2816 if (Ctx.getTypeSize(VariableType) <= 64 * 8 &&
2817 (VariableType.isTriviallyCopyableType(Ctx) ||
2818 hasTrivialABIAttr(VariableType)))
2821 // Suggest changing from a const variable to a const reference variable
2822 // if doing so will prevent a copy.
2823 SemaRef.Diag(VD->getLocation(), diag::warn_for_range_copy)
2824 << VD << VariableType << InitExpr->getType();
2825 SemaRef.Diag(VD->getBeginLoc(), diag::note_use_reference_type)
2826 << SemaRef.Context.getLValueReferenceType(VariableType)
2827 << VD->getSourceRange()
2828 << FixItHint::CreateInsertion(VD->getLocation(), "&");
2831 /// DiagnoseForRangeVariableCopies - Diagnose three cases and fixes for them.
2832 /// 1) for (const foo &x : foos) where foos only returns a copy. Suggest
2833 /// using "const foo x" to show that a copy is made
2834 /// 2) for (const bar &x : foos) where bar is a temporary initialized by bar.
2835 /// Suggest either "const bar x" to keep the copying or "const foo& x" to
2836 /// prevent the copy.
2837 /// 3) for (const foo x : foos) where x is constructed from a reference foo.
2838 /// Suggest "const foo &x" to prevent the copy.
2839 static void DiagnoseForRangeVariableCopies(Sema &SemaRef,
2840 const CXXForRangeStmt *ForStmt) {
2841 if (SemaRef.inTemplateInstantiation())
2844 if (SemaRef.Diags.isIgnored(diag::warn_for_range_const_reference_copy,
2845 ForStmt->getBeginLoc()) &&
2846 SemaRef.Diags.isIgnored(diag::warn_for_range_variable_always_copy,
2847 ForStmt->getBeginLoc()) &&
2848 SemaRef.Diags.isIgnored(diag::warn_for_range_copy,
2849 ForStmt->getBeginLoc())) {
2853 const VarDecl *VD = ForStmt->getLoopVariable();
2857 QualType VariableType = VD->getType();
2859 if (VariableType->isIncompleteType())
2862 const Expr *InitExpr = VD->getInit();
2866 if (InitExpr->getExprLoc().isMacroID())
2869 if (VariableType->isReferenceType()) {
2870 DiagnoseForRangeReferenceVariableCopies(SemaRef, VD,
2871 ForStmt->getRangeInit()->getType());
2872 } else if (VariableType.isConstQualified()) {
2873 DiagnoseForRangeConstVariableCopies(SemaRef, VD);
2877 /// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement.
2878 /// This is a separate step from ActOnCXXForRangeStmt because analysis of the
2879 /// body cannot be performed until after the type of the range variable is
2881 StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) {
2885 if (isa<ObjCForCollectionStmt>(S))
2886 return FinishObjCForCollectionStmt(S, B);
2888 CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S);
2889 ForStmt->setBody(B);
2891 DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B,
2892 diag::warn_empty_range_based_for_body);
2894 DiagnoseForRangeVariableCopies(*this, ForStmt);
2899 StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc,
2900 SourceLocation LabelLoc,
2901 LabelDecl *TheDecl) {
2902 setFunctionHasBranchIntoScope();
2903 TheDecl->markUsed(Context);
2904 return new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc);
2908 Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc,
2910 // Convert operand to void*
2911 if (!E->isTypeDependent()) {
2912 QualType ETy = E->getType();
2913 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst());
2914 ExprResult ExprRes = E;
2915 AssignConvertType ConvTy =
2916 CheckSingleAssignmentConstraints(DestTy, ExprRes);
2917 if (ExprRes.isInvalid())
2920 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing))
2924 ExprResult ExprRes = ActOnFinishFullExpr(E, /*DiscardedValue*/ false);
2925 if (ExprRes.isInvalid())
2929 setFunctionHasIndirectGoto();
2931 return new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E);
2934 static void CheckJumpOutOfSEHFinally(Sema &S, SourceLocation Loc,
2935 const Scope &DestScope) {
2936 if (!S.CurrentSEHFinally.empty() &&
2937 DestScope.Contains(*S.CurrentSEHFinally.back())) {
2938 S.Diag(Loc, diag::warn_jump_out_of_seh_finally);
2943 Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) {
2944 Scope *S = CurScope->getContinueParent();
2946 // C99 6.8.6.2p1: A break shall appear only in or as a loop body.
2947 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop));
2949 CheckJumpOutOfSEHFinally(*this, ContinueLoc, *S);
2951 return new (Context) ContinueStmt(ContinueLoc);
2955 Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) {
2956 Scope *S = CurScope->getBreakParent();
2958 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body.
2959 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch));
2961 if (S->isOpenMPLoopScope())
2962 return StmtError(Diag(BreakLoc, diag::err_omp_loop_cannot_use_stmt)
2964 CheckJumpOutOfSEHFinally(*this, BreakLoc, *S);
2966 return new (Context) BreakStmt(BreakLoc);
2969 /// Determine whether the given expression is a candidate for
2970 /// copy elision in either a return statement or a throw expression.
2972 /// \param ReturnType If we're determining the copy elision candidate for
2973 /// a return statement, this is the return type of the function. If we're
2974 /// determining the copy elision candidate for a throw expression, this will
2977 /// \param E The expression being returned from the function or block, or
2980 /// \param CESK Whether we allow function parameters or
2981 /// id-expressions that could be moved out of the function to be considered NRVO
2982 /// candidates. C++ prohibits these for NRVO itself, but we re-use this logic to
2983 /// determine whether we should try to move as part of a return or throw (which
2984 /// does allow function parameters).
2986 /// \returns The NRVO candidate variable, if the return statement may use the
2987 /// NRVO, or NULL if there is no such candidate.
2988 VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, Expr *E,
2989 CopyElisionSemanticsKind CESK) {
2990 // - in a return statement in a function [where] ...
2991 // ... the expression is the name of a non-volatile automatic object ...
2992 DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens());
2993 if (!DR || DR->refersToEnclosingVariableOrCapture())
2995 VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
2999 if (isCopyElisionCandidate(ReturnType, VD, CESK))
3004 bool Sema::isCopyElisionCandidate(QualType ReturnType, const VarDecl *VD,
3005 CopyElisionSemanticsKind CESK) {
3006 QualType VDType = VD->getType();
3007 // - in a return statement in a function with ...
3008 // ... a class return type ...
3009 if (!ReturnType.isNull() && !ReturnType->isDependentType()) {
3010 if (!ReturnType->isRecordType())
3012 // ... the same cv-unqualified type as the function return type ...
3013 // When considering moving this expression out, allow dissimilar types.
3014 if (!(CESK & CES_AllowDifferentTypes) && !VDType->isDependentType() &&
3015 !Context.hasSameUnqualifiedType(ReturnType, VDType))
3019 // ...object (other than a function or catch-clause parameter)...
3020 if (VD->getKind() != Decl::Var &&
3021 !((CESK & CES_AllowParameters) && VD->getKind() == Decl::ParmVar))
3023 if (!(CESK & CES_AllowExceptionVariables) && VD->isExceptionVariable())
3027 if (!VD->hasLocalStorage()) return false;
3029 // Return false if VD is a __block variable. We don't want to implicitly move
3030 // out of a __block variable during a return because we cannot assume the
3031 // variable will no longer be used.
3032 if (VD->hasAttr<BlocksAttr>()) return false;
3034 if (CESK & CES_AllowDifferentTypes)
3037 // ...non-volatile...
3038 if (VD->getType().isVolatileQualified()) return false;
3040 // Variables with higher required alignment than their type's ABI
3041 // alignment cannot use NRVO.
3042 if (!VD->getType()->isDependentType() && VD->hasAttr<AlignedAttr>() &&
3043 Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType()))
3049 /// Try to perform the initialization of a potentially-movable value,
3050 /// which is the operand to a return or throw statement.
3052 /// This routine implements C++14 [class.copy]p32, which attempts to treat
3053 /// returned lvalues as rvalues in certain cases (to prefer move construction),
3054 /// then falls back to treating them as lvalues if that failed.
3056 /// \param ConvertingConstructorsOnly If true, follow [class.copy]p32 and reject
3057 /// resolutions that find non-constructors, such as derived-to-base conversions
3058 /// or `operator T()&&` member functions. If false, do consider such
3059 /// conversion sequences.
3061 /// \param Res We will fill this in if move-initialization was possible.
3062 /// If move-initialization is not possible, such that we must fall back to
3063 /// treating the operand as an lvalue, we will leave Res in its original
3065 static void TryMoveInitialization(Sema& S,
3066 const InitializedEntity &Entity,
3067 const VarDecl *NRVOCandidate,
3068 QualType ResultType,
3070 bool ConvertingConstructorsOnly,
3072 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, Value->getType(),
3073 CK_NoOp, Value, VK_XValue);
3075 Expr *InitExpr = &AsRvalue;
3077 InitializationKind Kind = InitializationKind::CreateCopy(
3078 Value->getBeginLoc(), Value->getBeginLoc());
3080 InitializationSequence Seq(S, Entity, Kind, InitExpr);
3085 for (const InitializationSequence::Step &Step : Seq.steps()) {
3086 if (Step.Kind != InitializationSequence::SK_ConstructorInitialization &&
3087 Step.Kind != InitializationSequence::SK_UserConversion)
3090 FunctionDecl *FD = Step.Function.Function;
3091 if (ConvertingConstructorsOnly) {
3092 if (isa<CXXConstructorDecl>(FD)) {
3093 // C++14 [class.copy]p32:
3094 // [...] If the first overload resolution fails or was not performed,
3095 // or if the type of the first parameter of the selected constructor
3096 // is not an rvalue reference to the object's type (possibly
3097 // cv-qualified), overload resolution is performed again, considering
3098 // the object as an lvalue.
3099 const RValueReferenceType *RRefType =
3100 FD->getParamDecl(0)->getType()->getAs<RValueReferenceType>();
3103 if (!S.Context.hasSameUnqualifiedType(RRefType->getPointeeType(),
3104 NRVOCandidate->getType()))
3110 if (isa<CXXConstructorDecl>(FD)) {
3111 // Check that overload resolution selected a constructor taking an
3112 // rvalue reference. If it selected an lvalue reference, then we
3113 // didn't need to cast this thing to an rvalue in the first place.
3114 if (!isa<RValueReferenceType>(FD->getParamDecl(0)->getType()))
3116 } else if (isa<CXXMethodDecl>(FD)) {
3117 // Check that overload resolution selected a conversion operator
3118 // taking an rvalue reference.
3119 if (cast<CXXMethodDecl>(FD)->getRefQualifier() != RQ_RValue)
3126 // Promote "AsRvalue" to the heap, since we now need this
3127 // expression node to persist.
3128 Value = ImplicitCastExpr::Create(S.Context, Value->getType(), CK_NoOp,
3129 Value, nullptr, VK_XValue);
3131 // Complete type-checking the initialization of the return type
3132 // using the constructor we found.
3133 Res = Seq.Perform(S, Entity, Kind, Value);
3137 /// Perform the initialization of a potentially-movable value, which
3138 /// is the result of return value.
3140 /// This routine implements C++14 [class.copy]p32, which attempts to treat
3141 /// returned lvalues as rvalues in certain cases (to prefer move construction),
3142 /// then falls back to treating them as lvalues if that failed.
3144 Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
3145 const VarDecl *NRVOCandidate,
3146 QualType ResultType,
3149 // C++14 [class.copy]p32:
3150 // When the criteria for elision of a copy/move operation are met, but not for
3151 // an exception-declaration, and the object to be copied is designated by an
3152 // lvalue, or when the expression in a return statement is a (possibly
3153 // parenthesized) id-expression that names an object with automatic storage
3154 // duration declared in the body or parameter-declaration-clause of the
3155 // innermost enclosing function or lambda-expression, overload resolution to
3156 // select the constructor for the copy is first performed as if the object
3157 // were designated by an rvalue.
3158 ExprResult Res = ExprError();
3161 bool AffectedByCWG1579 = false;
3163 if (!NRVOCandidate) {
3164 NRVOCandidate = getCopyElisionCandidate(ResultType, Value, CES_Default);
3165 if (NRVOCandidate &&
3166 !getDiagnostics().isIgnored(diag::warn_return_std_move_in_cxx11,
3167 Value->getExprLoc())) {
3168 const VarDecl *NRVOCandidateInCXX11 =
3169 getCopyElisionCandidate(ResultType, Value, CES_FormerDefault);
3170 AffectedByCWG1579 = (!NRVOCandidateInCXX11);
3174 if (NRVOCandidate) {
3175 TryMoveInitialization(*this, Entity, NRVOCandidate, ResultType, Value,
3179 if (!Res.isInvalid() && AffectedByCWG1579) {
3180 QualType QT = NRVOCandidate->getType();
3181 if (QT.getNonReferenceType()
3182 .getUnqualifiedType()
3183 .isTriviallyCopyableType(Context)) {
3184 // Adding 'std::move' around a trivially copyable variable is probably
3185 // pointless. Don't suggest it.
3187 // Common cases for this are returning unique_ptr<Derived> from a
3188 // function of return type unique_ptr<Base>, or returning T from a
3189 // function of return type Expected<T>. This is totally fine in a
3190 // post-CWG1579 world, but was not fine before.
3191 assert(!ResultType.isNull());
3192 SmallString<32> Str;
3193 Str += "std::move(";
3194 Str += NRVOCandidate->getDeclName().getAsString();
3196 Diag(Value->getExprLoc(), diag::warn_return_std_move_in_cxx11)
3197 << Value->getSourceRange()
3198 << NRVOCandidate->getDeclName() << ResultType << QT;
3199 Diag(Value->getExprLoc(), diag::note_add_std_move_in_cxx11)
3200 << FixItHint::CreateReplacement(Value->getSourceRange(), Str);
3202 } else if (Res.isInvalid() &&
3203 !getDiagnostics().isIgnored(diag::warn_return_std_move,
3204 Value->getExprLoc())) {
3205 const VarDecl *FakeNRVOCandidate =
3206 getCopyElisionCandidate(QualType(), Value, CES_AsIfByStdMove);
3207 if (FakeNRVOCandidate) {
3208 QualType QT = FakeNRVOCandidate->getType();
3209 if (QT->isLValueReferenceType()) {
3210 // Adding 'std::move' around an lvalue reference variable's name is
3211 // dangerous. Don't suggest it.
3212 } else if (QT.getNonReferenceType()
3213 .getUnqualifiedType()
3214 .isTriviallyCopyableType(Context)) {
3215 // Adding 'std::move' around a trivially copyable variable is probably
3216 // pointless. Don't suggest it.
3218 ExprResult FakeRes = ExprError();
3219 Expr *FakeValue = Value;
3220 TryMoveInitialization(*this, Entity, FakeNRVOCandidate, ResultType,
3221 FakeValue, false, FakeRes);
3222 if (!FakeRes.isInvalid()) {
3224 (Entity.getKind() == InitializedEntity::EK_Exception);
3225 SmallString<32> Str;
3226 Str += "std::move(";
3227 Str += FakeNRVOCandidate->getDeclName().getAsString();
3229 Diag(Value->getExprLoc(), diag::warn_return_std_move)
3230 << Value->getSourceRange()
3231 << FakeNRVOCandidate->getDeclName() << IsThrow;
3232 Diag(Value->getExprLoc(), diag::note_add_std_move)
3233 << FixItHint::CreateReplacement(Value->getSourceRange(), Str);
3240 // Either we didn't meet the criteria for treating an lvalue as an rvalue,
3241 // above, or overload resolution failed. Either way, we need to try
3242 // (again) now with the return value expression as written.
3243 if (Res.isInvalid())
3244 Res = PerformCopyInitialization(Entity, SourceLocation(), Value);
3249 /// Determine whether the declared return type of the specified function
3250 /// contains 'auto'.
3251 static bool hasDeducedReturnType(FunctionDecl *FD) {
3252 const FunctionProtoType *FPT =
3253 FD->getTypeSourceInfo()->getType()->castAs<FunctionProtoType>();
3254 return FPT->getReturnType()->isUndeducedType();
3257 /// ActOnCapScopeReturnStmt - Utility routine to type-check return statements
3258 /// for capturing scopes.
3261 Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
3262 // If this is the first return we've seen, infer the return type.
3263 // [expr.prim.lambda]p4 in C++11; block literals follow the same rules.
3264 CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction());
3265 QualType FnRetType = CurCap->ReturnType;
3266 LambdaScopeInfo *CurLambda = dyn_cast<LambdaScopeInfo>(CurCap);
3267 bool HasDeducedReturnType =
3268 CurLambda && hasDeducedReturnType(CurLambda->CallOperator);
3270 if (ExprEvalContexts.back().Context ==
3271 ExpressionEvaluationContext::DiscardedStatement &&
3272 (HasDeducedReturnType || CurCap->HasImplicitReturnType)) {
3275 ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);
3278 RetValExp = ER.get();
3280 return ReturnStmt::Create(Context, ReturnLoc, RetValExp,
3281 /* NRVOCandidate=*/nullptr);
3284 if (HasDeducedReturnType) {
3285 // In C++1y, the return type may involve 'auto'.
3286 // FIXME: Blocks might have a return type of 'auto' explicitly specified.
3287 FunctionDecl *FD = CurLambda->CallOperator;
3288 if (CurCap->ReturnType.isNull())
3289 CurCap->ReturnType = FD->getReturnType();
3291 AutoType *AT = CurCap->ReturnType->getContainedAutoType();
3292 assert(AT && "lost auto type from lambda return type");
3293 if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) {
3294 FD->setInvalidDecl();
3297 CurCap->ReturnType = FnRetType = FD->getReturnType();
3298 } else if (CurCap->HasImplicitReturnType) {
3299 // For blocks/lambdas with implicit return types, we check each return
3300 // statement individually, and deduce the common return type when the block
3301 // or lambda is completed.
3302 // FIXME: Fold this into the 'auto' codepath above.
3303 if (RetValExp && !isa<InitListExpr>(RetValExp)) {
3304 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp);
3305 if (Result.isInvalid())
3307 RetValExp = Result.get();
3309 // DR1048: even prior to C++14, we should use the 'auto' deduction rules
3310 // when deducing a return type for a lambda-expression (or by extension
3311 // for a block). These rules differ from the stated C++11 rules only in
3312 // that they remove top-level cv-qualifiers.
3313 if (!CurContext->isDependentContext())
3314 FnRetType = RetValExp->getType().getUnqualifiedType();
3316 FnRetType = CurCap->ReturnType = Context.DependentTy;
3319 // C++11 [expr.lambda.prim]p4 bans inferring the result from an
3320 // initializer list, because it is not an expression (even
3321 // though we represent it as one). We still deduce 'void'.
3322 Diag(ReturnLoc, diag::err_lambda_return_init_list)
3323 << RetValExp->getSourceRange();
3326 FnRetType = Context.VoidTy;
3329 // Although we'll properly infer the type of the block once it's completed,
3330 // make sure we provide a return type now for better error recovery.
3331 if (CurCap->ReturnType.isNull())
3332 CurCap->ReturnType = FnRetType;
3334 assert(!FnRetType.isNull());
3336 if (auto *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) {
3337 if (CurBlock->FunctionType->castAs<FunctionType>()->getNoReturnAttr()) {
3338 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr);
3341 } else if (auto *CurRegion = dyn_cast<CapturedRegionScopeInfo>(CurCap)) {
3342 Diag(ReturnLoc, diag::err_return_in_captured_stmt) << CurRegion->getRegionName();
3345 assert(CurLambda && "unknown kind of captured scope");
3346 if (CurLambda->CallOperator->getType()
3347 ->castAs<FunctionType>()
3348 ->getNoReturnAttr()) {
3349 Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr);
3354 // Otherwise, verify that this result type matches the previous one. We are
3355 // pickier with blocks than for normal functions because we don't have GCC
3356 // compatibility to worry about here.
3357 const VarDecl *NRVOCandidate = nullptr;
3358 if (FnRetType->isDependentType()) {
3359 // Delay processing for now. TODO: there are lots of dependent
3360 // types we can conclusively prove aren't void.
3361 } else if (FnRetType->isVoidType()) {
3362 if (RetValExp && !isa<InitListExpr>(RetValExp) &&
3363 !(getLangOpts().CPlusPlus &&
3364 (RetValExp->isTypeDependent() ||
3365 RetValExp->getType()->isVoidType()))) {
3366 if (!getLangOpts().CPlusPlus &&
3367 RetValExp->getType()->isVoidType())
3368 Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2;
3370 Diag(ReturnLoc, diag::err_return_block_has_expr);
3371 RetValExp = nullptr;
3374 } else if (!RetValExp) {
3375 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr));
3376 } else if (!RetValExp->isTypeDependent()) {
3377 // we have a non-void block with an expression, continue checking
3379 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
3380 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
3383 // In C++ the return statement is handled via a copy initialization.
3384 // the C version of which boils down to CheckSingleAssignmentConstraints.
3385 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
3386 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
3388 NRVOCandidate != nullptr);
3389 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
3390 FnRetType, RetValExp);
3391 if (Res.isInvalid()) {
3392 // FIXME: Cleanup temporaries here, anyway?
3395 RetValExp = Res.get();
3396 CheckReturnValExpr(RetValExp, FnRetType, ReturnLoc);
3398 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
3403 ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);
3406 RetValExp = ER.get();
3409 ReturnStmt::Create(Context, ReturnLoc, RetValExp, NRVOCandidate);
3411 // If we need to check for the named return value optimization,
3412 // or if we need to infer the return type,
3413 // save the return statement in our scope for later processing.
3414 if (CurCap->HasImplicitReturnType || NRVOCandidate)
3415 FunctionScopes.back()->Returns.push_back(Result);
3417 if (FunctionScopes.back()->FirstReturnLoc.isInvalid())
3418 FunctionScopes.back()->FirstReturnLoc = ReturnLoc;
3424 /// Marks all typedefs in all local classes in a type referenced.
3426 /// In a function like
3428 /// struct S { typedef int a; };
3432 /// the local type escapes and could be referenced in some TUs but not in
3433 /// others. Pretend that all local typedefs are always referenced, to not warn
3434 /// on this. This isn't necessary if f has internal linkage, or the typedef
3436 class LocalTypedefNameReferencer
3437 : public RecursiveASTVisitor<LocalTypedefNameReferencer> {
3439 LocalTypedefNameReferencer(Sema &S) : S(S) {}
3440 bool VisitRecordType(const RecordType *RT);
3444 bool LocalTypedefNameReferencer::VisitRecordType(const RecordType *RT) {
3445 auto *R = dyn_cast<CXXRecordDecl>(RT->getDecl());
3446 if (!R || !R->isLocalClass() || !R->isLocalClass()->isExternallyVisible() ||
3447 R->isDependentType())
3449 for (auto *TmpD : R->decls())
3450 if (auto *T = dyn_cast<TypedefNameDecl>(TmpD))
3451 if (T->getAccess() != AS_private || R->hasFriends())
3452 S.MarkAnyDeclReferenced(T->getLocation(), T, /*OdrUse=*/false);
3457 TypeLoc Sema::getReturnTypeLoc(FunctionDecl *FD) const {
3458 return FD->getTypeSourceInfo()
3460 .getAsAdjusted<FunctionProtoTypeLoc>()
3464 /// Deduce the return type for a function from a returned expression, per
3465 /// C++1y [dcl.spec.auto]p6.
3466 bool Sema::DeduceFunctionTypeFromReturnExpr(FunctionDecl *FD,
3467 SourceLocation ReturnLoc,
3470 // If this is the conversion function for a lambda, we choose to deduce it
3471 // type from the corresponding call operator, not from the synthesized return
3472 // statement within it. See Sema::DeduceReturnType.
3473 if (isLambdaConversionOperator(FD))
3476 TypeLoc OrigResultType = getReturnTypeLoc(FD);
3479 if (RetExpr && isa<InitListExpr>(RetExpr)) {
3480 // If the deduction is for a return statement and the initializer is
3481 // a braced-init-list, the program is ill-formed.
3482 Diag(RetExpr->getExprLoc(),
3483 getCurLambda() ? diag::err_lambda_return_init_list
3484 : diag::err_auto_fn_return_init_list)
3485 << RetExpr->getSourceRange();
3489 if (FD->isDependentContext()) {
3490 // C++1y [dcl.spec.auto]p12:
3491 // Return type deduction [...] occurs when the definition is
3492 // instantiated even if the function body contains a return
3493 // statement with a non-type-dependent operand.
3494 assert(AT->isDeduced() && "should have deduced to dependent type");
3499 // Otherwise, [...] deduce a value for U using the rules of template
3500 // argument deduction.
3501 DeduceAutoResult DAR = DeduceAutoType(OrigResultType, RetExpr, Deduced);
3503 if (DAR == DAR_Failed && !FD->isInvalidDecl())
3504 Diag(RetExpr->getExprLoc(), diag::err_auto_fn_deduction_failure)
3505 << OrigResultType.getType() << RetExpr->getType();
3507 if (DAR != DAR_Succeeded)
3510 // If a local type is part of the returned type, mark its fields as
3512 LocalTypedefNameReferencer Referencer(*this);
3513 Referencer.TraverseType(RetExpr->getType());
3515 // In the case of a return with no operand, the initializer is considered
3518 // Deduction here can only succeed if the return type is exactly 'cv auto'
3519 // or 'decltype(auto)', so just check for that case directly.
3520 if (!OrigResultType.getType()->getAs<AutoType>()) {
3521 Diag(ReturnLoc, diag::err_auto_fn_return_void_but_not_auto)
3522 << OrigResultType.getType();
3525 // We always deduce U = void in this case.
3526 Deduced = SubstAutoType(OrigResultType.getType(), Context.VoidTy);
3527 if (Deduced.isNull())
3531 // CUDA: Kernel function must have 'void' return type.
3532 if (getLangOpts().CUDA)
3533 if (FD->hasAttr<CUDAGlobalAttr>() && !Deduced->isVoidType()) {
3534 Diag(FD->getLocation(), diag::err_kern_type_not_void_return)
3535 << FD->getType() << FD->getSourceRange();
3539 // If a function with a declared return type that contains a placeholder type
3540 // has multiple return statements, the return type is deduced for each return
3541 // statement. [...] if the type deduced is not the same in each deduction,
3542 // the program is ill-formed.
3543 QualType DeducedT = AT->getDeducedType();
3544 if (!DeducedT.isNull() && !FD->isInvalidDecl()) {
3545 AutoType *NewAT = Deduced->getContainedAutoType();
3546 // It is possible that NewAT->getDeducedType() is null. When that happens,
3547 // we should not crash, instead we ignore this deduction.
3548 if (NewAT->getDeducedType().isNull())
3551 CanQualType OldDeducedType = Context.getCanonicalFunctionResultType(
3553 CanQualType NewDeducedType = Context.getCanonicalFunctionResultType(
3554 NewAT->getDeducedType());
3555 if (!FD->isDependentContext() && OldDeducedType != NewDeducedType) {
3556 const LambdaScopeInfo *LambdaSI = getCurLambda();
3557 if (LambdaSI && LambdaSI->HasImplicitReturnType) {
3558 Diag(ReturnLoc, diag::err_typecheck_missing_return_type_incompatible)
3559 << NewAT->getDeducedType() << DeducedT
3560 << true /*IsLambda*/;
3562 Diag(ReturnLoc, diag::err_auto_fn_different_deductions)
3563 << (AT->isDecltypeAuto() ? 1 : 0)
3564 << NewAT->getDeducedType() << DeducedT;
3568 } else if (!FD->isInvalidDecl()) {
3569 // Update all declarations of the function to have the deduced return type.
3570 Context.adjustDeducedFunctionResultType(FD, Deduced);
3577 Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
3579 // Correct typos, in case the containing function returns 'auto' and
3580 // RetValExp should determine the deduced type.
3581 ExprResult RetVal = CorrectDelayedTyposInExpr(RetValExp);
3582 if (RetVal.isInvalid())
3584 StmtResult R = BuildReturnStmt(ReturnLoc, RetVal.get());
3585 if (R.isInvalid() || ExprEvalContexts.back().Context ==
3586 ExpressionEvaluationContext::DiscardedStatement)
3590 const_cast<VarDecl*>(cast<ReturnStmt>(R.get())->getNRVOCandidate())) {
3591 CurScope->addNRVOCandidate(VD);
3593 CurScope->setNoNRVO();
3596 CheckJumpOutOfSEHFinally(*this, ReturnLoc, *CurScope->getFnParent());
3601 StmtResult Sema::BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
3602 // Check for unexpanded parameter packs.
3603 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp))
3606 if (isa<CapturingScopeInfo>(getCurFunction()))
3607 return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp);
3610 QualType RelatedRetType;
3611 const AttrVec *Attrs = nullptr;
3612 bool isObjCMethod = false;
3614 if (const FunctionDecl *FD = getCurFunctionDecl()) {
3615 FnRetType = FD->getReturnType();
3617 Attrs = &FD->getAttrs();
3618 if (FD->isNoReturn())
3619 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr)
3620 << FD->getDeclName();
3621 if (FD->isMain() && RetValExp)
3622 if (isa<CXXBoolLiteralExpr>(RetValExp))
3623 Diag(ReturnLoc, diag::warn_main_returns_bool_literal)
3624 << RetValExp->getSourceRange();
3625 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) {
3626 FnRetType = MD->getReturnType();
3627 isObjCMethod = true;
3629 Attrs = &MD->getAttrs();
3630 if (MD->hasRelatedResultType() && MD->getClassInterface()) {
3631 // In the implementation of a method with a related return type, the
3632 // type used to type-check the validity of return statements within the
3633 // method body is a pointer to the type of the class being implemented.
3634 RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface());
3635 RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType);
3637 } else // If we don't have a function/method context, bail.
3640 // C++1z: discarded return statements are not considered when deducing a
3642 if (ExprEvalContexts.back().Context ==
3643 ExpressionEvaluationContext::DiscardedStatement &&
3644 FnRetType->getContainedAutoType()) {
3647 ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);
3650 RetValExp = ER.get();
3652 return ReturnStmt::Create(Context, ReturnLoc, RetValExp,
3653 /* NRVOCandidate=*/nullptr);
3656 // FIXME: Add a flag to the ScopeInfo to indicate whether we're performing
3658 if (getLangOpts().CPlusPlus14) {
3659 if (AutoType *AT = FnRetType->getContainedAutoType()) {
3660 FunctionDecl *FD = cast<FunctionDecl>(CurContext);
3661 if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) {
3662 FD->setInvalidDecl();
3665 FnRetType = FD->getReturnType();
3670 bool HasDependentReturnType = FnRetType->isDependentType();
3672 ReturnStmt *Result = nullptr;
3673 if (FnRetType->isVoidType()) {
3675 if (isa<InitListExpr>(RetValExp)) {
3676 // We simply never allow init lists as the return value of void
3677 // functions. This is compatible because this was never allowed before,
3678 // so there's no legacy code to deal with.
3679 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3680 int FunctionKind = 0;
3681 if (isa<ObjCMethodDecl>(CurDecl))
3683 else if (isa<CXXConstructorDecl>(CurDecl))
3685 else if (isa<CXXDestructorDecl>(CurDecl))
3688 Diag(ReturnLoc, diag::err_return_init_list)
3689 << CurDecl->getDeclName() << FunctionKind
3690 << RetValExp->getSourceRange();
3692 // Drop the expression.
3693 RetValExp = nullptr;
3694 } else if (!RetValExp->isTypeDependent()) {
3695 // C99 6.8.6.4p1 (ext_ since GCC warns)
3696 unsigned D = diag::ext_return_has_expr;
3697 if (RetValExp->getType()->isVoidType()) {
3698 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3699 if (isa<CXXConstructorDecl>(CurDecl) ||
3700 isa<CXXDestructorDecl>(CurDecl))
3701 D = diag::err_ctor_dtor_returns_void;
3703 D = diag::ext_return_has_void_expr;
3706 ExprResult Result = RetValExp;
3707 Result = IgnoredValueConversions(Result.get());
3708 if (Result.isInvalid())
3710 RetValExp = Result.get();
3711 RetValExp = ImpCastExprToType(RetValExp,
3712 Context.VoidTy, CK_ToVoid).get();
3714 // return of void in constructor/destructor is illegal in C++.
3715 if (D == diag::err_ctor_dtor_returns_void) {
3716 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3718 << CurDecl->getDeclName() << isa<CXXDestructorDecl>(CurDecl)
3719 << RetValExp->getSourceRange();
3721 // return (some void expression); is legal in C++.
3722 else if (D != diag::ext_return_has_void_expr ||
3723 !getLangOpts().CPlusPlus) {
3724 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3726 int FunctionKind = 0;
3727 if (isa<ObjCMethodDecl>(CurDecl))
3729 else if (isa<CXXConstructorDecl>(CurDecl))
3731 else if (isa<CXXDestructorDecl>(CurDecl))
3735 << CurDecl->getDeclName() << FunctionKind
3736 << RetValExp->getSourceRange();
3742 ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);
3745 RetValExp = ER.get();
3749 Result = ReturnStmt::Create(Context, ReturnLoc, RetValExp,
3750 /* NRVOCandidate=*/nullptr);
3751 } else if (!RetValExp && !HasDependentReturnType) {
3752 FunctionDecl *FD = getCurFunctionDecl();
3755 if (getLangOpts().CPlusPlus11 && FD && FD->isConstexpr()) {
3756 // C++11 [stmt.return]p2
3757 DiagID = diag::err_constexpr_return_missing_expr;
3758 FD->setInvalidDecl();
3759 } else if (getLangOpts().C99) {
3760 // C99 6.8.6.4p1 (ext_ since GCC warns)
3761 DiagID = diag::ext_return_missing_expr;
3764 DiagID = diag::warn_return_missing_expr;
3768 Diag(ReturnLoc, DiagID)
3769 << FD->getIdentifier() << 0 /*fn*/ << FD->isConsteval();
3771 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/;
3773 Result = ReturnStmt::Create(Context, ReturnLoc, /* RetExpr=*/nullptr,
3774 /* NRVOCandidate=*/nullptr);
3776 assert(RetValExp || HasDependentReturnType);
3777 const VarDecl *NRVOCandidate = nullptr;
3779 QualType RetType = RelatedRetType.isNull() ? FnRetType : RelatedRetType;
3781 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
3782 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
3785 // In C++ the return statement is handled via a copy initialization,
3786 // the C version of which boils down to CheckSingleAssignmentConstraints.
3788 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
3789 if (!HasDependentReturnType && !RetValExp->isTypeDependent()) {
3790 // we have a non-void function with an expression, continue checking
3791 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
3793 NRVOCandidate != nullptr);
3794 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
3795 RetType, RetValExp);
3796 if (Res.isInvalid()) {
3797 // FIXME: Clean up temporaries here anyway?
3800 RetValExp = Res.getAs<Expr>();
3802 // If we have a related result type, we need to implicitly
3803 // convert back to the formal result type. We can't pretend to
3804 // initialize the result again --- we might end double-retaining
3805 // --- so instead we initialize a notional temporary.
3806 if (!RelatedRetType.isNull()) {
3807 Entity = InitializedEntity::InitializeRelatedResult(getCurMethodDecl(),
3809 Res = PerformCopyInitialization(Entity, ReturnLoc, RetValExp);
3810 if (Res.isInvalid()) {
3811 // FIXME: Clean up temporaries here anyway?
3814 RetValExp = Res.getAs<Expr>();
3817 CheckReturnValExpr(RetValExp, FnRetType, ReturnLoc, isObjCMethod, Attrs,
3818 getCurFunctionDecl());
3823 ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);
3826 RetValExp = ER.get();
3828 Result = ReturnStmt::Create(Context, ReturnLoc, RetValExp, NRVOCandidate);
3831 // If we need to check for the named return value optimization, save the
3832 // return statement in our scope for later processing.
3833 if (Result->getNRVOCandidate())
3834 FunctionScopes.back()->Returns.push_back(Result);
3836 if (FunctionScopes.back()->FirstReturnLoc.isInvalid())
3837 FunctionScopes.back()->FirstReturnLoc = ReturnLoc;
3843 Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc,
3844 SourceLocation RParen, Decl *Parm,
3846 VarDecl *Var = cast_or_null<VarDecl>(Parm);
3847 if (Var && Var->isInvalidDecl())
3850 return new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body);
3854 Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) {
3855 return new (Context) ObjCAtFinallyStmt(AtLoc, Body);
3859 Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try,
3860 MultiStmtArg CatchStmts, Stmt *Finally) {
3861 if (!getLangOpts().ObjCExceptions)
3862 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try";
3864 setFunctionHasBranchProtectedScope();
3865 unsigned NumCatchStmts = CatchStmts.size();
3866 return ObjCAtTryStmt::Create(Context, AtLoc, Try, CatchStmts.data(),
3867 NumCatchStmts, Finally);
3870 StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw) {
3872 ExprResult Result = DefaultLvalueConversion(Throw);
3873 if (Result.isInvalid())
3876 Result = ActOnFinishFullExpr(Result.get(), /*DiscardedValue*/ false);
3877 if (Result.isInvalid())
3879 Throw = Result.get();
3881 QualType ThrowType = Throw->getType();
3882 // Make sure the expression type is an ObjC pointer or "void *".
3883 if (!ThrowType->isDependentType() &&
3884 !ThrowType->isObjCObjectPointerType()) {
3885 const PointerType *PT = ThrowType->getAs<PointerType>();
3886 if (!PT || !PT->getPointeeType()->isVoidType())
3887 return StmtError(Diag(AtLoc, diag::err_objc_throw_expects_object)
3888 << Throw->getType() << Throw->getSourceRange());
3892 return new (Context) ObjCAtThrowStmt(AtLoc, Throw);
3896 Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw,
3898 if (!getLangOpts().ObjCExceptions)
3899 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw";
3902 // @throw without an expression designates a rethrow (which must occur
3903 // in the context of an @catch clause).
3904 Scope *AtCatchParent = CurScope;
3905 while (AtCatchParent && !AtCatchParent->isAtCatchScope())
3906 AtCatchParent = AtCatchParent->getParent();
3908 return StmtError(Diag(AtLoc, diag::err_rethrow_used_outside_catch));
3910 return BuildObjCAtThrowStmt(AtLoc, Throw);
3914 Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) {
3915 ExprResult result = DefaultLvalueConversion(operand);
3916 if (result.isInvalid())
3918 operand = result.get();
3920 // Make sure the expression type is an ObjC pointer or "void *".
3921 QualType type = operand->getType();
3922 if (!type->isDependentType() &&
3923 !type->isObjCObjectPointerType()) {
3924 const PointerType *pointerType = type->getAs<PointerType>();
3925 if (!pointerType || !pointerType->getPointeeType()->isVoidType()) {
3926 if (getLangOpts().CPlusPlus) {
3927 if (RequireCompleteType(atLoc, type,
3928 diag::err_incomplete_receiver_type))
3929 return Diag(atLoc, diag::err_objc_synchronized_expects_object)
3930 << type << operand->getSourceRange();
3932 ExprResult result = PerformContextuallyConvertToObjCPointer(operand);
3933 if (result.isInvalid())
3935 if (!result.isUsable())
3936 return Diag(atLoc, diag::err_objc_synchronized_expects_object)
3937 << type << operand->getSourceRange();
3939 operand = result.get();
3941 return Diag(atLoc, diag::err_objc_synchronized_expects_object)
3942 << type << operand->getSourceRange();
3947 // The operand to @synchronized is a full-expression.
3948 return ActOnFinishFullExpr(operand, /*DiscardedValue*/ false);
3952 Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr,
3954 // We can't jump into or indirect-jump out of a @synchronized block.
3955 setFunctionHasBranchProtectedScope();
3956 return new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody);
3959 /// ActOnCXXCatchBlock - Takes an exception declaration and a handler block
3960 /// and creates a proper catch handler from them.
3962 Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl,
3963 Stmt *HandlerBlock) {
3964 // There's nothing to test that ActOnExceptionDecl didn't already test.
3965 return new (Context)
3966 CXXCatchStmt(CatchLoc, cast_or_null<VarDecl>(ExDecl), HandlerBlock);
3970 Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) {
3971 setFunctionHasBranchProtectedScope();
3972 return new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body);
3976 class CatchHandlerType {
3978 unsigned IsPointer : 1;
3980 // This is a special constructor to be used only with DenseMapInfo's
3981 // getEmptyKey() and getTombstoneKey() functions.
3982 friend struct llvm::DenseMapInfo<CatchHandlerType>;
3983 enum Unique { ForDenseMap };
3984 CatchHandlerType(QualType QT, Unique) : QT(QT), IsPointer(false) {}
3987 /// Used when creating a CatchHandlerType from a handler type; will determine
3988 /// whether the type is a pointer or reference and will strip off the top
3989 /// level pointer and cv-qualifiers.
3990 CatchHandlerType(QualType Q) : QT(Q), IsPointer(false) {
3991 if (QT->isPointerType())
3994 if (IsPointer || QT->isReferenceType())
3995 QT = QT->getPointeeType();
3996 QT = QT.getUnqualifiedType();
3999 /// Used when creating a CatchHandlerType from a base class type; pretends the
4000 /// type passed in had the pointer qualifier, does not need to get an
4001 /// unqualified type.
4002 CatchHandlerType(QualType QT, bool IsPointer)
4003 : QT(QT), IsPointer(IsPointer) {}
4005 QualType underlying() const { return QT; }
4006 bool isPointer() const { return IsPointer; }
4008 friend bool operator==(const CatchHandlerType &LHS,
4009 const CatchHandlerType &RHS) {
4010 // If the pointer qualification does not match, we can return early.
4011 if (LHS.IsPointer != RHS.IsPointer)
4013 // Otherwise, check the underlying type without cv-qualifiers.
4014 return LHS.QT == RHS.QT;
4020 template <> struct DenseMapInfo<CatchHandlerType> {
4021 static CatchHandlerType getEmptyKey() {
4022 return CatchHandlerType(DenseMapInfo<QualType>::getEmptyKey(),
4023 CatchHandlerType::ForDenseMap);
4026 static CatchHandlerType getTombstoneKey() {
4027 return CatchHandlerType(DenseMapInfo<QualType>::getTombstoneKey(),
4028 CatchHandlerType::ForDenseMap);
4031 static unsigned getHashValue(const CatchHandlerType &Base) {
4032 return DenseMapInfo<QualType>::getHashValue(Base.underlying());
4035 static bool isEqual(const CatchHandlerType &LHS,
4036 const CatchHandlerType &RHS) {
4043 class CatchTypePublicBases {
4045 const llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> &TypesToCheck;
4046 const bool CheckAgainstPointer;
4048 CXXCatchStmt *FoundHandler;
4049 CanQualType FoundHandlerType;
4052 CatchTypePublicBases(
4054 const llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> &T, bool C)
4055 : Ctx(Ctx), TypesToCheck(T), CheckAgainstPointer(C),
4056 FoundHandler(nullptr) {}
4058 CXXCatchStmt *getFoundHandler() const { return FoundHandler; }
4059 CanQualType getFoundHandlerType() const { return FoundHandlerType; }
4061 bool operator()(const CXXBaseSpecifier *S, CXXBasePath &) {
4062 if (S->getAccessSpecifier() == AccessSpecifier::AS_public) {
4063 CatchHandlerType Check(S->getType(), CheckAgainstPointer);
4064 const auto &M = TypesToCheck;
4065 auto I = M.find(Check);
4067 FoundHandler = I->second;
4068 FoundHandlerType = Ctx.getCanonicalType(S->getType());
4077 /// ActOnCXXTryBlock - Takes a try compound-statement and a number of
4078 /// handlers and creates a try statement from them.
4079 StmtResult Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock,
4080 ArrayRef<Stmt *> Handlers) {
4081 // Don't report an error if 'try' is used in system headers.
4082 if (!getLangOpts().CXXExceptions &&
4083 !getSourceManager().isInSystemHeader(TryLoc) && !getLangOpts().CUDA) {
4084 // Delay error emission for the OpenMP device code.
4085 targetDiag(TryLoc, diag::err_exceptions_disabled) << "try";
4088 // Exceptions aren't allowed in CUDA device code.
4089 if (getLangOpts().CUDA)
4090 CUDADiagIfDeviceCode(TryLoc, diag::err_cuda_device_exceptions)
4091 << "try" << CurrentCUDATarget();
4093 if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
4094 Diag(TryLoc, diag::err_omp_simd_region_cannot_use_stmt) << "try";
4096 sema::FunctionScopeInfo *FSI = getCurFunction();
4098 // C++ try is incompatible with SEH __try.
4099 if (!getLangOpts().Borland && FSI->FirstSEHTryLoc.isValid()) {
4100 Diag(TryLoc, diag::err_mixing_cxx_try_seh_try);
4101 Diag(FSI->FirstSEHTryLoc, diag::note_conflicting_try_here) << "'__try'";
4104 const unsigned NumHandlers = Handlers.size();
4105 assert(!Handlers.empty() &&
4106 "The parser shouldn't call this if there are no handlers.");
4108 llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> HandledTypes;
4109 for (unsigned i = 0; i < NumHandlers; ++i) {
4110 CXXCatchStmt *H = cast<CXXCatchStmt>(Handlers[i]);
4112 // Diagnose when the handler is a catch-all handler, but it isn't the last
4113 // handler for the try block. [except.handle]p5. Also, skip exception
4114 // declarations that are invalid, since we can't usefully report on them.
4115 if (!H->getExceptionDecl()) {
4116 if (i < NumHandlers - 1)
4117 return StmtError(Diag(H->getBeginLoc(), diag::err_early_catch_all));
4119 } else if (H->getExceptionDecl()->isInvalidDecl())
4122 // Walk the type hierarchy to diagnose when this type has already been
4123 // handled (duplication), or cannot be handled (derivation inversion). We
4124 // ignore top-level cv-qualifiers, per [except.handle]p3
4125 CatchHandlerType HandlerCHT =
4126 (QualType)Context.getCanonicalType(H->getCaughtType());
4128 // We can ignore whether the type is a reference or a pointer; we need the
4129 // underlying declaration type in order to get at the underlying record
4130 // decl, if there is one.
4131 QualType Underlying = HandlerCHT.underlying();
4132 if (auto *RD = Underlying->getAsCXXRecordDecl()) {
4133 if (!RD->hasDefinition())
4135 // Check that none of the public, unambiguous base classes are in the
4136 // map ([except.handle]p1). Give the base classes the same pointer
4137 // qualification as the original type we are basing off of. This allows
4138 // comparison against the handler type using the same top-level pointer
4139 // as the original type.
4141 Paths.setOrigin(RD);
4142 CatchTypePublicBases CTPB(Context, HandledTypes, HandlerCHT.isPointer());
4143 if (RD->lookupInBases(CTPB, Paths)) {
4144 const CXXCatchStmt *Problem = CTPB.getFoundHandler();
4145 if (!Paths.isAmbiguous(CTPB.getFoundHandlerType())) {
4146 Diag(H->getExceptionDecl()->getTypeSpecStartLoc(),
4147 diag::warn_exception_caught_by_earlier_handler)
4148 << H->getCaughtType();
4149 Diag(Problem->getExceptionDecl()->getTypeSpecStartLoc(),
4150 diag::note_previous_exception_handler)
4151 << Problem->getCaughtType();
4156 // Add the type the list of ones we have handled; diagnose if we've already
4158 auto R = HandledTypes.insert(std::make_pair(H->getCaughtType(), H));
4160 const CXXCatchStmt *Problem = R.first->second;
4161 Diag(H->getExceptionDecl()->getTypeSpecStartLoc(),
4162 diag::warn_exception_caught_by_earlier_handler)
4163 << H->getCaughtType();
4164 Diag(Problem->getExceptionDecl()->getTypeSpecStartLoc(),
4165 diag::note_previous_exception_handler)
4166 << Problem->getCaughtType();
4170 FSI->setHasCXXTry(TryLoc);
4172 return CXXTryStmt::Create(Context, TryLoc, TryBlock, Handlers);
4175 StmtResult Sema::ActOnSEHTryBlock(bool IsCXXTry, SourceLocation TryLoc,
4176 Stmt *TryBlock, Stmt *Handler) {
4177 assert(TryBlock && Handler);
4179 sema::FunctionScopeInfo *FSI = getCurFunction();
4181 // SEH __try is incompatible with C++ try. Borland appears to support this,
4183 if (!getLangOpts().Borland) {
4184 if (FSI->FirstCXXTryLoc.isValid()) {
4185 Diag(TryLoc, diag::err_mixing_cxx_try_seh_try);
4186 Diag(FSI->FirstCXXTryLoc, diag::note_conflicting_try_here) << "'try'";
4190 FSI->setHasSEHTry(TryLoc);
4192 // Reject __try in Obj-C methods, blocks, and captured decls, since we don't
4193 // track if they use SEH.
4194 DeclContext *DC = CurContext;
4195 while (DC && !DC->isFunctionOrMethod())
4196 DC = DC->getParent();
4197 FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(DC);
4199 FD->setUsesSEHTry(true);
4201 Diag(TryLoc, diag::err_seh_try_outside_functions);
4203 // Reject __try on unsupported targets.
4204 if (!Context.getTargetInfo().isSEHTrySupported())
4205 Diag(TryLoc, diag::err_seh_try_unsupported);
4207 return SEHTryStmt::Create(Context, IsCXXTry, TryLoc, TryBlock, Handler);
4210 StmtResult Sema::ActOnSEHExceptBlock(SourceLocation Loc, Expr *FilterExpr,
4212 assert(FilterExpr && Block);
4213 QualType FTy = FilterExpr->getType();
4214 if (!FTy->isIntegerType() && !FTy->isDependentType()) {
4216 Diag(FilterExpr->getExprLoc(), diag::err_filter_expression_integral)
4219 return SEHExceptStmt::Create(Context, Loc, FilterExpr, Block);
4222 void Sema::ActOnStartSEHFinallyBlock() {
4223 CurrentSEHFinally.push_back(CurScope);
4226 void Sema::ActOnAbortSEHFinallyBlock() {
4227 CurrentSEHFinally.pop_back();
4230 StmtResult Sema::ActOnFinishSEHFinallyBlock(SourceLocation Loc, Stmt *Block) {
4232 CurrentSEHFinally.pop_back();
4233 return SEHFinallyStmt::Create(Context, Loc, Block);
4237 Sema::ActOnSEHLeaveStmt(SourceLocation Loc, Scope *CurScope) {
4238 Scope *SEHTryParent = CurScope;
4239 while (SEHTryParent && !SEHTryParent->isSEHTryScope())
4240 SEHTryParent = SEHTryParent->getParent();
4242 return StmtError(Diag(Loc, diag::err_ms___leave_not_in___try));
4243 CheckJumpOutOfSEHFinally(*this, Loc, *SEHTryParent);
4245 return new (Context) SEHLeaveStmt(Loc);
4248 StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc,
4250 NestedNameSpecifierLoc QualifierLoc,
4251 DeclarationNameInfo NameInfo,
4254 return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists,
4255 QualifierLoc, NameInfo,
4256 cast<CompoundStmt>(Nested));
4260 StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc,
4263 UnqualifiedId &Name,
4265 return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists,
4266 SS.getWithLocInContext(Context),
4267 GetNameFromUnqualifiedId(Name),
4272 Sema::CreateCapturedStmtRecordDecl(CapturedDecl *&CD, SourceLocation Loc,
4273 unsigned NumParams) {
4274 DeclContext *DC = CurContext;
4275 while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext()))
4276 DC = DC->getParent();
4278 RecordDecl *RD = nullptr;
4279 if (getLangOpts().CPlusPlus)
4280 RD = CXXRecordDecl::Create(Context, TTK_Struct, DC, Loc, Loc,
4283 RD = RecordDecl::Create(Context, TTK_Struct, DC, Loc, Loc, /*Id=*/nullptr);
4285 RD->setCapturedRecord();
4288 RD->startDefinition();
4290 assert(NumParams > 0 && "CapturedStmt requires context parameter");
4291 CD = CapturedDecl::Create(Context, CurContext, NumParams);
4297 buildCapturedStmtCaptureList(Sema &S, CapturedRegionScopeInfo *RSI,
4298 SmallVectorImpl<CapturedStmt::Capture> &Captures,
4299 SmallVectorImpl<Expr *> &CaptureInits) {
4300 for (const sema::Capture &Cap : RSI->Captures) {
4301 if (Cap.isInvalid())
4304 // Form the initializer for the capture.
4305 ExprResult Init = S.BuildCaptureInit(Cap, Cap.getLocation(),
4306 RSI->CapRegionKind == CR_OpenMP);
4308 // FIXME: Bail out now if the capture is not used and the initializer has
4311 // Create a field for this capture.
4312 FieldDecl *Field = S.BuildCaptureField(RSI->TheRecordDecl, Cap);
4314 // Add the capture to our list of captures.
4315 if (Cap.isThisCapture()) {
4316 Captures.push_back(CapturedStmt::Capture(Cap.getLocation(),
4317 CapturedStmt::VCK_This));
4318 } else if (Cap.isVLATypeCapture()) {
4320 CapturedStmt::Capture(Cap.getLocation(), CapturedStmt::VCK_VLAType));
4322 assert(Cap.isVariableCapture() && "unknown kind of capture");
4324 if (S.getLangOpts().OpenMP && RSI->CapRegionKind == CR_OpenMP)
4325 S.setOpenMPCaptureKind(Field, Cap.getVariable(), RSI->OpenMPLevel);
4327 Captures.push_back(CapturedStmt::Capture(Cap.getLocation(),
4328 Cap.isReferenceCapture()
4329 ? CapturedStmt::VCK_ByRef
4330 : CapturedStmt::VCK_ByCopy,
4331 Cap.getVariable()));
4333 CaptureInits.push_back(Init.get());
4338 void Sema::ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
4339 CapturedRegionKind Kind,
4340 unsigned NumParams) {
4341 CapturedDecl *CD = nullptr;
4342 RecordDecl *RD = CreateCapturedStmtRecordDecl(CD, Loc, NumParams);
4344 // Build the context parameter
4345 DeclContext *DC = CapturedDecl::castToDeclContext(CD);
4346 IdentifierInfo *ParamName = &Context.Idents.get("__context");
4347 QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD));
4349 ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType,
4350 ImplicitParamDecl::CapturedContext);
4353 CD->setContextParam(0, Param);
4355 // Enter the capturing scope for this captured region.
4356 PushCapturedRegionScope(CurScope, CD, RD, Kind);
4359 PushDeclContext(CurScope, CD);
4363 PushExpressionEvaluationContext(
4364 ExpressionEvaluationContext::PotentiallyEvaluated);
4367 void Sema::ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
4368 CapturedRegionKind Kind,
4369 ArrayRef<CapturedParamNameType> Params,
4370 unsigned OpenMPCaptureLevel) {
4371 CapturedDecl *CD = nullptr;
4372 RecordDecl *RD = CreateCapturedStmtRecordDecl(CD, Loc, Params.size());
4374 // Build the context parameter
4375 DeclContext *DC = CapturedDecl::castToDeclContext(CD);
4376 bool ContextIsFound = false;
4377 unsigned ParamNum = 0;
4378 for (ArrayRef<CapturedParamNameType>::iterator I = Params.begin(),
4380 I != E; ++I, ++ParamNum) {
4381 if (I->second.isNull()) {
4382 assert(!ContextIsFound &&
4383 "null type has been found already for '__context' parameter");
4384 IdentifierInfo *ParamName = &Context.Idents.get("__context");
4385 QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD))
4389 ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType,
4390 ImplicitParamDecl::CapturedContext);
4392 CD->setContextParam(ParamNum, Param);
4393 ContextIsFound = true;
4395 IdentifierInfo *ParamName = &Context.Idents.get(I->first);
4397 ImplicitParamDecl::Create(Context, DC, Loc, ParamName, I->second,
4398 ImplicitParamDecl::CapturedContext);
4400 CD->setParam(ParamNum, Param);
4403 assert(ContextIsFound && "no null type for '__context' parameter");
4404 if (!ContextIsFound) {
4405 // Add __context implicitly if it is not specified.
4406 IdentifierInfo *ParamName = &Context.Idents.get("__context");
4407 QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD));
4409 ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType,
4410 ImplicitParamDecl::CapturedContext);
4412 CD->setContextParam(ParamNum, Param);
4414 // Enter the capturing scope for this captured region.
4415 PushCapturedRegionScope(CurScope, CD, RD, Kind, OpenMPCaptureLevel);
4418 PushDeclContext(CurScope, CD);
4422 PushExpressionEvaluationContext(
4423 ExpressionEvaluationContext::PotentiallyEvaluated);
4426 void Sema::ActOnCapturedRegionError() {
4427 DiscardCleanupsInEvaluationContext();
4428 PopExpressionEvaluationContext();
4430 PoppedFunctionScopePtr ScopeRAII = PopFunctionScopeInfo();
4431 CapturedRegionScopeInfo *RSI = cast<CapturedRegionScopeInfo>(ScopeRAII.get());
4433 RecordDecl *Record = RSI->TheRecordDecl;
4434 Record->setInvalidDecl();
4436 SmallVector<Decl*, 4> Fields(Record->fields());
4437 ActOnFields(/*Scope=*/nullptr, Record->getLocation(), Record, Fields,
4438 SourceLocation(), SourceLocation(), ParsedAttributesView());
4441 StmtResult Sema::ActOnCapturedRegionEnd(Stmt *S) {
4442 // Leave the captured scope before we start creating captures in the
4444 DiscardCleanupsInEvaluationContext();
4445 PopExpressionEvaluationContext();
4447 PoppedFunctionScopePtr ScopeRAII = PopFunctionScopeInfo();
4448 CapturedRegionScopeInfo *RSI = cast<CapturedRegionScopeInfo>(ScopeRAII.get());
4450 SmallVector<CapturedStmt::Capture, 4> Captures;
4451 SmallVector<Expr *, 4> CaptureInits;
4452 if (buildCapturedStmtCaptureList(*this, RSI, Captures, CaptureInits))
4455 CapturedDecl *CD = RSI->TheCapturedDecl;
4456 RecordDecl *RD = RSI->TheRecordDecl;
4458 CapturedStmt *Res = CapturedStmt::Create(
4459 getASTContext(), S, static_cast<CapturedRegionKind>(RSI->CapRegionKind),
4460 Captures, CaptureInits, CD, RD);
4462 CD->setBody(Res->getCapturedStmt());
4463 RD->completeDefinition();