diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 2362e479dfbbc..e498969b2c46b 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -434,6 +434,9 @@ Bug Fixes to C++ Support - Fix crash caused by a spaceship operator returning a comparision category by reference. Fixes: (`#64162 `_) +- Fix a crash when calling a consteval function in an expression used as + the size of an array. + (`#65520 `_) - Clang no longer tries to capture non-odr-used variables that appear in the enclosing expression of a lambda expression with a noexcept specifier. diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h index 0e969f341bbe1..79ac622fd03e2 100644 --- a/clang/include/clang/Parse/Parser.h +++ b/clang/include/clang/Parse/Parser.h @@ -1766,6 +1766,7 @@ class Parser : public CodeCompletionHandler { ExprResult ParseConstantExpressionInExprEvalContext( TypeCastState isTypeCast = NotTypeCast); ExprResult ParseConstantExpression(); + ExprResult ParseArrayBoundExpression(); ExprResult ParseCaseExpression(SourceLocation CaseLoc); ExprResult ParseConstraintExpression(); ExprResult diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h index 79361aa19a567..1037086d12afb 100644 --- a/clang/include/clang/Sema/Sema.h +++ b/clang/include/clang/Sema/Sema.h @@ -1062,20 +1062,6 @@ class Sema final { } }; - /// Whether the AST is currently being rebuilt to correct immediate - /// invocations. Immediate invocation candidates and references to consteval - /// functions aren't tracked when this is set. - bool RebuildingImmediateInvocation = false; - - /// Used to change context to isConstantEvaluated without pushing a heavy - /// ExpressionEvaluationContextRecord object. - bool isConstantEvaluatedOverride; - - bool isConstantEvaluated() const { - return ExprEvalContexts.back().isConstantEvaluated() || - isConstantEvaluatedOverride; - } - /// RAII object to handle the state changes required to synthesize /// a function body. class SynthesizedFunctionScope { @@ -1361,6 +1347,11 @@ class Sema final { bool IsCurrentlyCheckingDefaultArgumentOrInitializer = false; + // We are in a constant context, but we also allow + // non constant expressions, for example for array bounds (which may be + // VLAs). + bool InConditionallyConstantEvaluateContext = false; + // When evaluating immediate functions in the initializer of a default // argument or default member initializer, this is the declaration whose // default initializer is being evaluated and the location of the call @@ -9878,30 +9869,44 @@ class Sema final { /// diagnostics that will be suppressed. std::optional isSFINAEContext() const; - /// Determines whether we are currently in a context that - /// is not evaluated as per C++ [expr] p5. - bool isUnevaluatedContext() const { + /// Whether the AST is currently being rebuilt to correct immediate + /// invocations. Immediate invocation candidates and references to consteval + /// functions aren't tracked when this is set. + bool RebuildingImmediateInvocation = false; + + /// Used to change context to isConstantEvaluated without pushing a heavy + /// ExpressionEvaluationContextRecord object. + bool isConstantEvaluatedOverride = false; + + const ExpressionEvaluationContextRecord ¤tEvaluationContext() const { assert(!ExprEvalContexts.empty() && "Must be in an expression evaluation context"); - return ExprEvalContexts.back().isUnevaluated(); - } + return ExprEvalContexts.back(); + }; bool isConstantEvaluatedContext() const { - assert(!ExprEvalContexts.empty() && - "Must be in an expression evaluation context"); - return ExprEvalContexts.back().isConstantEvaluated(); + return currentEvaluationContext().isConstantEvaluated() || + isConstantEvaluatedOverride; + } + + bool isAlwaysConstantEvaluatedContext() const { + const ExpressionEvaluationContextRecord &Ctx = currentEvaluationContext(); + return (Ctx.isConstantEvaluated() || isConstantEvaluatedOverride) && + !Ctx.InConditionallyConstantEvaluateContext; + } + + /// Determines whether we are currently in a context that + /// is not evaluated as per C++ [expr] p5. + bool isUnevaluatedContext() const { + return currentEvaluationContext().isUnevaluated(); } bool isImmediateFunctionContext() const { - assert(!ExprEvalContexts.empty() && - "Must be in an expression evaluation context"); - return ExprEvalContexts.back().isImmediateFunctionContext(); + return currentEvaluationContext().isImmediateFunctionContext(); } bool isCheckingDefaultArgumentOrInitializer() const { - assert(!ExprEvalContexts.empty() && - "Must be in an expression evaluation context"); - const ExpressionEvaluationContextRecord &Ctx = ExprEvalContexts.back(); + const ExpressionEvaluationContextRecord &Ctx = currentEvaluationContext(); return (Ctx.Context == ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed) || Ctx.IsCurrentlyCheckingDefaultArgumentOrInitializer; diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp index 3cad57e719aad..93515940d15df 100644 --- a/clang/lib/Parse/ParseDecl.cpp +++ b/clang/lib/Parse/ParseDecl.cpp @@ -7703,7 +7703,7 @@ void Parser::ParseBracketDeclarator(Declarator &D) { // Parse the constant-expression or assignment-expression now (depending // on dialect). if (getLangOpts().CPlusPlus) { - NumElements = ParseConstantExpression(); + NumElements = ParseArrayBoundExpression(); } else { EnterExpressionEvaluationContext Unevaluated( Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated); diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp index 711990bff2851..9dbfc1c8c5e9f 100644 --- a/clang/lib/Parse/ParseExpr.cpp +++ b/clang/lib/Parse/ParseExpr.cpp @@ -221,6 +221,15 @@ ExprResult Parser::ParseConstantExpression() { return ParseConstantExpressionInExprEvalContext(NotTypeCast); } +ExprResult Parser::ParseArrayBoundExpression() { + EnterExpressionEvaluationContext ConstantEvaluated( + Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated); + // If we parse the bound of a VLA... we parse a non-constant + // constant-expression! + Actions.ExprEvalContexts.back().InConditionallyConstantEvaluateContext = true; + return ParseConstantExpressionInExprEvalContext(NotTypeCast); +} + ExprResult Parser::ParseCaseExpression(SourceLocation CaseLoc) { EnterExpressionEvaluationContext ConstantEvaluated( Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated); diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp index 4489cb0deae4c..db81fa645a27f 100644 --- a/clang/lib/Sema/Sema.cpp +++ b/clang/lib/Sema/Sema.cpp @@ -221,7 +221,6 @@ Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer, CurScope(nullptr), Ident_super(nullptr) { assert(pp.TUKind == TUKind); TUScope = nullptr; - isConstantEvaluatedOverride = false; LoadedExternalKnownNamespaces = false; for (unsigned I = 0; I != NSAPI::NumNSNumberLiteralMethods; ++I) diff --git a/clang/lib/Sema/SemaCUDA.cpp b/clang/lib/Sema/SemaCUDA.cpp index 3336dbf474df0..7c4083e4ec4d4 100644 --- a/clang/lib/Sema/SemaCUDA.cpp +++ b/clang/lib/Sema/SemaCUDA.cpp @@ -812,7 +812,7 @@ bool Sema::CheckCUDACall(SourceLocation Loc, FunctionDecl *Callee) { assert(getLangOpts().CUDA && "Should only be called during CUDA compilation"); assert(Callee && "Callee may not be null."); - auto &ExprEvalCtx = ExprEvalContexts.back(); + const auto &ExprEvalCtx = currentEvaluationContext(); if (ExprEvalCtx.isUnevaluated() || ExprEvalCtx.isConstantEvaluated()) return true; diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 3b0cc154c2e46..995accfaaeb24 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -1076,7 +1076,7 @@ static bool ProcessFormatStringLiteral(const Expr *FormatExpr, void Sema::checkFortifiedBuiltinMemoryFunction(FunctionDecl *FD, CallExpr *TheCall) { if (TheCall->isValueDependent() || TheCall->isTypeDependent() || - isConstantEvaluated()) + isConstantEvaluatedContext()) return; bool UseDABAttr = false; @@ -3192,7 +3192,7 @@ bool Sema::CheckCDEBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID, bool Sema::CheckARMCoprocessorImmediate(const TargetInfo &TI, const Expr *CoprocArg, bool WantCDE) { - if (isConstantEvaluated()) + if (isConstantEvaluatedContext()) return false; // We can't check the value of a dependent argument. @@ -6616,7 +6616,7 @@ static void CheckNonNullArguments(Sema &S, assert((FDecl || Proto) && "Need a function declaration or prototype"); // Already checked by constant evaluator. - if (S.isConstantEvaluated()) + if (S.isConstantEvaluatedContext()) return; // Check the attributes attached to the method/function itself. llvm::SmallBitVector NonNullArgs; @@ -8980,7 +8980,7 @@ bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum, /// TheCall is a constant expression in the range [Low, High]. bool Sema::SemaBuiltinConstantArgRange(CallExpr *TheCall, int ArgNum, int Low, int High, bool RangeIsError) { - if (isConstantEvaluated()) + if (isConstantEvaluatedContext()) return false; llvm::APSInt Result; @@ -9694,7 +9694,7 @@ checkFormatStringExpr(Sema &S, const Expr *E, ArrayRef Args, llvm::SmallBitVector &CheckedVarArgs, UncoveredArgHandler &UncoveredArg, llvm::APSInt Offset, bool IgnoreStringsWithoutSpecifiers = false) { - if (S.isConstantEvaluated()) + if (S.isConstantEvaluatedContext()) return SLCT_NotALiteral; tryAgain: assert(Offset.isSigned() && "invalid offset"); @@ -9734,8 +9734,8 @@ checkFormatStringExpr(Sema &S, const Expr *E, ArrayRef Args, bool CheckLeft = true, CheckRight = true; bool Cond; - if (C->getCond()->EvaluateAsBooleanCondition(Cond, S.getASTContext(), - S.isConstantEvaluated())) { + if (C->getCond()->EvaluateAsBooleanCondition( + Cond, S.getASTContext(), S.isConstantEvaluatedContext())) { if (Cond) CheckRight = false; else @@ -9999,9 +9999,11 @@ checkFormatStringExpr(Sema &S, const Expr *E, ArrayRef Args, Expr::EvalResult LResult, RResult; bool LIsInt = BinOp->getLHS()->EvaluateAsInt( - LResult, S.Context, Expr::SE_NoSideEffects, S.isConstantEvaluated()); + LResult, S.Context, Expr::SE_NoSideEffects, + S.isConstantEvaluatedContext()); bool RIsInt = BinOp->getRHS()->EvaluateAsInt( - RResult, S.Context, Expr::SE_NoSideEffects, S.isConstantEvaluated()); + RResult, S.Context, Expr::SE_NoSideEffects, + S.isConstantEvaluatedContext()); if (LIsInt != RIsInt) { BinaryOperatorKind BinOpKind = BinOp->getOpcode(); @@ -10029,7 +10031,7 @@ checkFormatStringExpr(Sema &S, const Expr *E, ArrayRef Args, Expr::EvalResult IndexResult; if (ASE->getRHS()->EvaluateAsInt(IndexResult, S.Context, Expr::SE_NoSideEffects, - S.isConstantEvaluated())) { + S.isConstantEvaluatedContext())) { sumOffsets(Offset, IndexResult.Val.getInt(), BO_Add, /*RHS is int*/ true); E = ASE->getBase(); @@ -13959,7 +13961,7 @@ static bool CheckTautologicalComparison(Sema &S, BinaryOperator *E, return false; IntRange OtherValueRange = GetExprRange( - S.Context, Other, S.isConstantEvaluated(), /*Approximate*/ false); + S.Context, Other, S.isConstantEvaluatedContext(), /*Approximate=*/false); QualType OtherT = Other->getType(); if (const auto *AT = OtherT->getAs()) @@ -14174,8 +14176,9 @@ static void AnalyzeComparison(Sema &S, BinaryOperator *E) { } // Otherwise, calculate the effective range of the signed operand. - IntRange signedRange = GetExprRange( - S.Context, signedOperand, S.isConstantEvaluated(), /*Approximate*/ true); + IntRange signedRange = + GetExprRange(S.Context, signedOperand, S.isConstantEvaluatedContext(), + /*Approximate=*/true); // Go ahead and analyze implicit conversions in the operands. Note // that we skip the implicit conversions on both sides. @@ -14193,8 +14196,8 @@ static void AnalyzeComparison(Sema &S, BinaryOperator *E) { if (E->isEqualityOp()) { unsigned comparisonWidth = S.Context.getIntWidth(T); IntRange unsignedRange = - GetExprRange(S.Context, unsignedOperand, S.isConstantEvaluated(), - /*Approximate*/ true); + GetExprRange(S.Context, unsignedOperand, S.isConstantEvaluatedContext(), + /*Approximate=*/true); // We should never be unable to prove that the unsigned operand is // non-negative. @@ -15057,7 +15060,7 @@ static void CheckImplicitConversion(Sema &S, Expr *E, QualType T, if (Target->isUnsaturatedFixedPointType()) { Expr::EvalResult Result; if (E->EvaluateAsFixedPoint(Result, S.Context, Expr::SE_AllowSideEffects, - S.isConstantEvaluated())) { + S.isConstantEvaluatedContext())) { llvm::APFixedPoint Value = Result.Val.getFixedPoint(); llvm::APFixedPoint MaxVal = S.Context.getFixedPointMax(T); llvm::APFixedPoint MinVal = S.Context.getFixedPointMin(T); @@ -15072,7 +15075,7 @@ static void CheckImplicitConversion(Sema &S, Expr *E, QualType T, } } else if (Target->isIntegerType()) { Expr::EvalResult Result; - if (!S.isConstantEvaluated() && + if (!S.isConstantEvaluatedContext() && E->EvaluateAsFixedPoint(Result, S.Context, Expr::SE_AllowSideEffects)) { llvm::APFixedPoint FXResult = Result.Val.getFixedPoint(); @@ -15095,7 +15098,7 @@ static void CheckImplicitConversion(Sema &S, Expr *E, QualType T, } else if (Target->isUnsaturatedFixedPointType()) { if (Source->isIntegerType()) { Expr::EvalResult Result; - if (!S.isConstantEvaluated() && + if (!S.isConstantEvaluatedContext() && E->EvaluateAsInt(Result, S.Context, Expr::SE_AllowSideEffects)) { llvm::APSInt Value = Result.Val.getInt(); @@ -15121,8 +15124,9 @@ static void CheckImplicitConversion(Sema &S, Expr *E, QualType T, if (SourceBT && TargetBT && SourceBT->isIntegerType() && TargetBT->isFloatingType() && !IsListInit) { // Determine the number of precision bits in the source integer type. - IntRange SourceRange = GetExprRange(S.Context, E, S.isConstantEvaluated(), - /*Approximate*/ true); + IntRange SourceRange = + GetExprRange(S.Context, E, S.isConstantEvaluatedContext(), + /*Approximate=*/true); unsigned int SourcePrecision = SourceRange.Width; // Determine the number of precision bits in the @@ -15190,8 +15194,8 @@ static void CheckImplicitConversion(Sema &S, Expr *E, QualType T, IntRange SourceTypeRange = IntRange::forTargetOfCanonicalType(S.Context, Source); - IntRange LikelySourceRange = - GetExprRange(S.Context, E, S.isConstantEvaluated(), /*Approximate*/ true); + IntRange LikelySourceRange = GetExprRange( + S.Context, E, S.isConstantEvaluatedContext(), /*Approximate=*/true); IntRange TargetRange = IntRange::forTargetOfCanonicalType(S.Context, Target); if (LikelySourceRange.Width > TargetRange.Width) { @@ -15199,7 +15203,7 @@ static void CheckImplicitConversion(Sema &S, Expr *E, QualType T, // TODO: this should happen for bitfield stores, too. Expr::EvalResult Result; if (E->EvaluateAsInt(Result, S.Context, Expr::SE_AllowSideEffects, - S.isConstantEvaluated())) { + S.isConstantEvaluatedContext())) { llvm::APSInt Value(32); Value = Result.Val.getInt(); @@ -16063,7 +16067,8 @@ class SequenceChecker : public ConstEvaluatedExprVisitor { if (!EvalOK || E->isValueDependent()) return false; EvalOK = E->EvaluateAsBooleanCondition( - Result, Self.SemaRef.Context, Self.SemaRef.isConstantEvaluated()); + Result, Self.SemaRef.Context, + Self.SemaRef.isConstantEvaluatedContext()); return EvalOK; } @@ -17190,7 +17195,7 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr, const ArraySubscriptExpr *ASE, bool AllowOnePastEnd, bool IndexNegated) { // Already diagnosed by the constant evaluator. - if (isConstantEvaluated()) + if (isConstantEvaluatedContext()) return; IndexExpr = IndexExpr->IgnoreParenImpCasts(); @@ -18579,7 +18584,7 @@ void Sema::CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr, TypeTagData TypeInfo; if (!GetMatchingCType(ArgumentKind, TypeTagExpr, Context, TypeTagForDatatypeMagicValues.get(), FoundWrongKind, - TypeInfo, isConstantEvaluated())) { + TypeInfo, isConstantEvaluatedContext())) { if (FoundWrongKind) Diag(TypeTagExpr->getExprLoc(), diag::warn_type_tag_for_datatype_wrong_kind) diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index 304aa7d105e26..9c5f96eebd041 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -18312,7 +18312,7 @@ void Sema::MarkExpressionAsImmediateEscalating(Expr *E) { ExprResult Sema::CheckForImmediateInvocation(ExprResult E, FunctionDecl *Decl) { if (isUnevaluatedContext() || !E.isUsable() || !Decl || - !Decl->isImmediateFunction() || isConstantEvaluated() || + !Decl->isImmediateFunction() || isAlwaysConstantEvaluatedContext() || isCheckingDefaultArgumentOrInitializer() || RebuildingImmediateInvocation || isImmediateFunctionContext()) return E; @@ -20736,7 +20736,7 @@ void Sema::MarkDeclRefReferenced(DeclRefExpr *E, const Expr *Base) { OdrUse = false; if (auto *FD = dyn_cast(E->getDecl())) { - if (!isUnevaluatedContext() && !isConstantEvaluated() && + if (!isUnevaluatedContext() && !isConstantEvaluatedContext() && !isImmediateFunctionContext() && !isCheckingDefaultArgumentOrInitializer() && FD->isImmediateFunction() && !RebuildingImmediateInvocation && diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h index 0fc5ad8e3bde6..bcaad0950fa92 100644 --- a/clang/lib/Sema/TreeTransform.h +++ b/clang/lib/Sema/TreeTransform.h @@ -5490,6 +5490,9 @@ TreeTransform::TransformDependentSizedArrayType(TypeLocBuilder &TLB, EnterExpressionEvaluationContext Unevaluated( SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated); + // If we have a VLA then it won't be a constant. + SemaRef.ExprEvalContexts.back().InConditionallyConstantEvaluateContext = true; + // Prefer the expression from the TypeLoc; the other may have been uniqued. Expr *origSize = TL.getSizeExpr(); if (!origSize) origSize = T->getSizeExpr(); diff --git a/clang/test/SemaCXX/cxx2a-consteval.cpp b/clang/test/SemaCXX/cxx2a-consteval.cpp index a091fadfa3094..38cc4be32a27c 100644 --- a/clang/test/SemaCXX/cxx2a-consteval.cpp +++ b/clang/test/SemaCXX/cxx2a-consteval.cpp @@ -8,7 +8,7 @@ consteval int f1(int i) { return i; } -consteval constexpr int f2(int i) { +consteval constexpr int f2(int i) { //expected-error@-1 {{cannot combine}} return i; } @@ -195,7 +195,7 @@ auto ptr = ret1(0); struct A { consteval int f(int) { // expected-note@-1+ {{declared here}} - return 0; + return 0; } }; @@ -239,7 +239,7 @@ constexpr int f_c(int i) { int t = f(i); // expected-error@-1 {{is not a constant expression}} // expected-note@-2 {{function parameter}} - return f(0); + return f(0); } consteval int f_eval(int i) { @@ -675,7 +675,7 @@ Bar a; // expected-note {{in instantiation of member function 'issue_55601 struct constantDerp { // Can be used in a constant expression. - consteval constantDerp(int) {} + consteval constantDerp(int) {} consteval operator int() const { return 5; } }; Bar b; @@ -1175,4 +1175,28 @@ struct T { static constexpr auto xx = ns::foo(A{}); // expected-error {{cannot take address of consteval function 'foo' outside of an immediate invocation}} }; +} + +namespace GH65520 { + +consteval int bar (int i) { if (i != 1) return 1/0; return 0; } +// expected-note@-1{{division by zero}} + +void +g () +{ + int a_ok[bar(1)]; + int a_err[bar(3)]; // expected-error {{call to consteval function 'GH65520::bar' is not a constant expression}} \ + // expected-note {{in call to 'bar(3)'}} +} + +consteval int undefined(); // expected-note {{declared here}} + +consteval void immediate() { + int a [undefined()]; // expected-note {{undefined function 'undefined' cannot be used in a constant expression}} \ + // expected-error {{call to consteval function 'GH65520::undefined' is not a constant expression}} \ + // expected-error {{variable of non-literal type 'int[undefined()]' cannot be defined in a constexpr function before C++23}} +} + + } diff --git a/clang/unittests/Support/TimeProfilerTest.cpp b/clang/unittests/Support/TimeProfilerTest.cpp index fdfbbfe4e3a9d..a7ca2bf91e474 100644 --- a/clang/unittests/Support/TimeProfilerTest.cpp +++ b/clang/unittests/Support/TimeProfilerTest.cpp @@ -190,6 +190,7 @@ Frontend | EvaluateAsInitializer (slow_value) | EvaluateAsConstantExpr () | EvaluateAsConstantExpr () +| EvaluateAsConstantExpr () | EvaluateAsRValue () | EvaluateAsInitializer (slow_init_list) | PerformPendingInstantiations