C++20 Feature Support
^^^^^^^^^^^^^^^^^^^^^
+- Clang now correctly delays the instantiation of function constraints until
+ the time of checking, which should now allow the libstdc++ ranges implementation
+ to work for at least trivial examples. This fixes
+ `Issue 44178 <https://github.com/llvm/llvm-project/issues/44178>`_.
- Support capturing structured bindings in lambdas
(`P1091R3 <https://wg21.link/p1091r3>`_ and `P1381R1 <https://wg21.link/P1381R1>`).
bool ConsiderCudaAttrs = true,
bool ConsiderRequiresClauses = true);
+ // Calculates whether the expression Constraint depends on an enclosing
+ // template, for the purposes of [temp.friend] p9.
+ // TemplateDepth is the 'depth' of the friend function, which is used to
+ // compare whether a declaration reference is referring to a containing
+ // template, or just the current friend function. A 'lower' TemplateDepth in
+ // the AST refers to a 'containing' template. As the constraint is
+ // uninstantiated, this is relative to the 'top' of the TU.
+ bool ConstraintExpressionDependsOnEnclosingTemplate(unsigned TemplateDepth,
+ const Expr *Constraint);
+
enum class AllowedExplicit {
/// Allow no explicit functions to be used.
None,
LocalInstantiationScope &Scope,
const MultiLevelTemplateArgumentList &TemplateArgs);
+ /// used by SetupConstraintCheckingTemplateArgumentsAndScope to recursively(in
+ /// the case of lambdas) set up the LocalInstantiationScope of the current
+ /// function.
+ bool SetupConstraintScope(
+ FunctionDecl *FD, llvm::Optional<ArrayRef<TemplateArgument>> TemplateArgs,
+ MultiLevelTemplateArgumentList MLTAL, LocalInstantiationScope &Scope);
+
+ /// Used during constraint checking, sets up the constraint template arguemnt
+ /// lists, and calls SetupConstraintScope to set up the
+ /// LocalInstantiationScope to have the proper set of ParVarDecls configured.
+ llvm::Optional<MultiLevelTemplateArgumentList>
+ SetupConstraintCheckingTemplateArgumentsAndScope(
+ FunctionDecl *FD, llvm::Optional<ArrayRef<TemplateArgument>> TemplateArgs,
+ LocalInstantiationScope &Scope);
+
public:
const NormalizedConstraint *
getNormalizedAssociatedConstraints(
bool CheckConstraintSatisfaction(
const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
const MultiLevelTemplateArgumentList &TemplateArgLists,
+ SourceRange TemplateIDRange, ConstraintSatisfaction &Satisfaction) {
+ llvm::SmallVector<Expr *, 4> Converted;
+ return CheckConstraintSatisfaction(Template, ConstraintExprs, Converted,
+ TemplateArgLists, TemplateIDRange,
+ Satisfaction);
+ }
+
+ /// \brief Check whether the given list of constraint expressions are
+ /// satisfied (as if in a 'conjunction') given template arguments.
+ /// Additionally, takes an empty list of Expressions which is populated with
+ /// the instantiated versions of the ConstraintExprs.
+ /// \param Template the template-like entity that triggered the constraints
+ /// check (either a concept or a constrained entity).
+ /// \param ConstraintExprs a list of constraint expressions, treated as if
+ /// they were 'AND'ed together.
+ /// \param ConvertedConstraints a out parameter that will get populated with
+ /// the instantiated version of the ConstraintExprs if we successfully checked
+ /// satisfaction.
+ /// \param TemplateArgList the multi-level list of template arguments to
+ /// substitute into the constraint expression. This should be relative to the
+ /// top-level (hence multi-level), since we need to instantiate fully at the
+ /// time of checking.
+ /// \param TemplateIDRange The source range of the template id that
+ /// caused the constraints check.
+ /// \param Satisfaction if true is returned, will contain details of the
+ /// satisfaction, with enough information to diagnose an unsatisfied
+ /// expression.
+ /// \returns true if an error occurred and satisfaction could not be checked,
+ /// false otherwise.
+ bool CheckConstraintSatisfaction(
+ const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
+ llvm::SmallVectorImpl<Expr *> &ConvertedConstraints,
+ const MultiLevelTemplateArgumentList &TemplateArgList,
SourceRange TemplateIDRange, ConstraintSatisfaction &Satisfaction);
/// \brief Check whether the given non-dependent constraint expression is
/// \returns true if an error occurred, false otherwise.
bool CheckFunctionConstraints(const FunctionDecl *FD,
ConstraintSatisfaction &Satisfaction,
- SourceLocation UsageLoc = SourceLocation());
-
+ SourceLocation UsageLoc = SourceLocation(),
+ bool ForOverloadResolution = false);
/// \brief Ensure that the given template arguments satisfy the constraints
/// associated with the given template, emitting a diagnostic if they do not.
MultiLevelTemplateArgumentList getTemplateInstantiationArgs(
const NamedDecl *D, const TemplateArgumentList *Innermost = nullptr,
- bool RelativeToPrimary = false, const FunctionDecl *Pattern = nullptr);
+ bool RelativeToPrimary = false, const FunctionDecl *Pattern = nullptr,
+ bool LookBeyondLambda = false, bool IncludeContainingStruct = false);
/// A context in which code is being synthesized (where a source location
/// alone is not sufficient to identify the context). This covers template
const MultiLevelTemplateArgumentList &TemplateArgs,
SourceLocation Loc, DeclarationName Entity);
- TypeSourceInfo *SubstFunctionDeclType(TypeSourceInfo *T,
- const MultiLevelTemplateArgumentList &TemplateArgs,
- SourceLocation Loc,
- DeclarationName Entity,
- CXXRecordDecl *ThisContext,
- Qualifiers ThisTypeQuals);
+ TypeSourceInfo *SubstFunctionDeclType(
+ TypeSourceInfo *T, const MultiLevelTemplateArgumentList &TemplateArgs,
+ SourceLocation Loc, DeclarationName Entity, CXXRecordDecl *ThisContext,
+ Qualifiers ThisTypeQuals, bool EvaluateConstraints = true);
void SubstExceptionSpec(FunctionDecl *New, const FunctionProtoType *Proto,
const MultiLevelTemplateArgumentList &Args);
bool SubstExceptionSpec(SourceLocation Loc,
FunctionProtoType::ExceptionSpecInfo &ESI,
SmallVectorImpl<QualType> &ExceptionStorage,
const MultiLevelTemplateArgumentList &Args);
- ParmVarDecl *SubstParmVarDecl(ParmVarDecl *D,
- const MultiLevelTemplateArgumentList &TemplateArgs,
- int indexAdjustment,
- Optional<unsigned> NumExpansions,
- bool ExpectParameterPack);
+ ParmVarDecl *
+ SubstParmVarDecl(ParmVarDecl *D,
+ const MultiLevelTemplateArgumentList &TemplateArgs,
+ int indexAdjustment, Optional<unsigned> NumExpansions,
+ bool ExpectParameterPack, bool EvaluateConstraints = true);
bool SubstParmTypes(SourceLocation Loc, ArrayRef<ParmVarDecl *> Params,
const FunctionProtoType::ExtParameterInfo *ExtParamInfos,
const MultiLevelTemplateArgumentList &TemplateArgs,
ExprResult SubstExpr(Expr *E,
const MultiLevelTemplateArgumentList &TemplateArgs);
+ // A RAII type used by the TemplateDeclInstantiator and TemplateInstantiator
+ // to disable constraint evaluation, then restore the state.
+ template <typename InstTy> struct ConstraintEvalRAII {
+ InstTy &TI;
+ bool OldValue;
+
+ ConstraintEvalRAII(InstTy &TI)
+ : TI(TI), OldValue(TI.getEvaluateConstraints()) {
+ TI.setEvaluateConstraints(false);
+ }
+ ~ConstraintEvalRAII() { TI.setEvaluateConstraints(OldValue); }
+ };
+
+ // Unlike the above, this evaluates constraints, which should only happen at
+ // 'constraint checking' time.
+ ExprResult
+ SubstConstraintExpr(Expr *E,
+ const MultiLevelTemplateArgumentList &TemplateArgs);
+
/// Substitute the given template arguments into a list of
/// expressions, expanding pack expansions if required.
///
const MultiLevelTemplateArgumentList &TemplateArgs,
TemplateArgumentListInfo &Outputs);
-
Decl *SubstDecl(Decl *D, DeclContext *Owner,
const MultiLevelTemplateArgumentList &TemplateArgs);
const MultiLevelTemplateArgumentList &TemplateArgs);
bool SubstTypeConstraint(TemplateTypeParmDecl *Inst, const TypeConstraint *TC,
- const MultiLevelTemplateArgumentList &TemplateArgs);
+ const MultiLevelTemplateArgumentList &TemplateArgs,
+ bool EvaluateConstraint);
bool InstantiateDefaultArgument(SourceLocation CallLoc, FunctionDecl *FD,
ParmVarDecl *Param);
const MultiLevelTemplateArgumentList &TemplateArgs;
Sema::LateInstantiatedAttrVec* LateAttrs = nullptr;
LocalInstantiationScope *StartingScope = nullptr;
+ bool EvaluateConstraints = true;
/// A list of out-of-line class template partial
/// specializations that will need to be instantiated after the
SubstIndex(SemaRef, SemaRef.ArgumentPackSubstitutionIndex),
Owner(Owner), TemplateArgs(TemplateArgs) {}
+ void setEvaluateConstraints(bool B) {
+ EvaluateConstraints = B;
+ }
+ bool getEvaluateConstraints() {
+ return EvaluateConstraints;
+ }
+
// Define all the decl visitors using DeclNodes.inc
#define DECL(DERIVED, BASE) \
Decl *Visit ## DERIVED ## Decl(DERIVED ## Decl *D);
#include "clang/Sema/Template.h"
#include "clang/Sema/Overload.h"
#include "clang/Sema/Initialization.h"
+#include "clang/AST/ASTLambda.h"
#include "clang/AST/ExprConcepts.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Basic/OperatorPrecedence.h"
namespace {
class LogicalBinOp {
+ SourceLocation Loc;
OverloadedOperatorKind Op = OO_None;
const Expr *LHS = nullptr;
const Expr *RHS = nullptr;
Op = BinaryOperator::getOverloadedOperator(BO->getOpcode());
LHS = BO->getLHS();
RHS = BO->getRHS();
+ Loc = BO->getExprLoc();
} else if (auto *OO = dyn_cast<CXXOperatorCallExpr>(E)) {
// If OO is not || or && it might not have exactly 2 arguments.
if (OO->getNumArgs() == 2) {
Op = OO->getOperator();
LHS = OO->getArg(0);
RHS = OO->getArg(1);
+ Loc = OO->getOperatorLoc();
}
}
}
const Expr *getLHS() const { return LHS; }
const Expr *getRHS() const { return RHS; }
+
+ ExprResult recreateBinOp(Sema &SemaRef, ExprResult LHS) const {
+ return recreateBinOp(SemaRef, LHS, const_cast<Expr *>(getRHS()));
+ }
+
+ ExprResult recreateBinOp(Sema &SemaRef, ExprResult LHS,
+ ExprResult RHS) const {
+ assert((isAnd() || isOr()) && "Not the right kind of op?");
+ assert((!LHS.isInvalid() && !RHS.isInvalid()) && "not good expressions?");
+
+ if (!LHS.isUsable() || !RHS.isUsable())
+ return ExprEmpty();
+
+ // We should just be able to 'normalize' these to the builtin Binary
+ // Operator, since that is how they are evaluated in constriant checks.
+ return BinaryOperator::Create(SemaRef.Context, LHS.get(), RHS.get(),
+ BinaryOperator::getOverloadedOpcode(Op),
+ SemaRef.Context.BoolTy, VK_PRValue,
+ OK_Ordinary, Loc, FPOptionsOverride{});
+ }
};
}
}
template <typename AtomicEvaluator>
-static bool
+static ExprResult
calculateConstraintSatisfaction(Sema &S, const Expr *ConstraintExpr,
ConstraintSatisfaction &Satisfaction,
AtomicEvaluator &&Evaluator) {
ConstraintExpr = ConstraintExpr->IgnoreParenImpCasts();
if (LogicalBinOp BO = ConstraintExpr) {
- if (calculateConstraintSatisfaction(S, BO.getLHS(), Satisfaction,
- Evaluator))
- return true;
+ ExprResult LHSRes = calculateConstraintSatisfaction(
+ S, BO.getLHS(), Satisfaction, Evaluator);
+
+ if (LHSRes.isInvalid())
+ return ExprError();
bool IsLHSSatisfied = Satisfaction.IsSatisfied;
// is checked. If that is satisfied, the disjunction is satisfied.
// Otherwise, the disjunction is satisfied if and only if the second
// operand is satisfied.
- return false;
+ return BO.recreateBinOp(S, LHSRes);
if (BO.isAnd() && !IsLHSSatisfied)
// [temp.constr.op] p2
// is checked. If that is not satisfied, the conjunction is not
// satisfied. Otherwise, the conjunction is satisfied if and only if
// the second operand is satisfied.
- return false;
+ return BO.recreateBinOp(S, LHSRes);
- return calculateConstraintSatisfaction(
+ ExprResult RHSRes = calculateConstraintSatisfaction(
S, BO.getRHS(), Satisfaction, std::forward<AtomicEvaluator>(Evaluator));
- } else if (auto *C = dyn_cast<ExprWithCleanups>(ConstraintExpr)) {
- return calculateConstraintSatisfaction(S, C->getSubExpr(), Satisfaction,
+ if (RHSRes.isInvalid())
+ return ExprError();
+
+ return BO.recreateBinOp(S, LHSRes, RHSRes);
+ }
+
+ if (auto *C = dyn_cast<ExprWithCleanups>(ConstraintExpr)) {
+ // These aren't evaluated, so we don't care about cleanups, so we can just
+ // evaluate these as if the cleanups didn't exist.
+ return calculateConstraintSatisfaction(
+ S, C->getSubExpr(), Satisfaction,
std::forward<AtomicEvaluator>(Evaluator));
}
ExprResult SubstitutedAtomicExpr = Evaluator(ConstraintExpr);
if (SubstitutedAtomicExpr.isInvalid())
- return true;
+ return ExprError();
if (!SubstitutedAtomicExpr.isUsable())
// Evaluator has decided satisfaction without yielding an expression.
- return false;
+ return ExprEmpty();
EnterExpressionEvaluationContext ConstantEvaluated(
S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
<< SubstitutedAtomicExpr.get()->getSourceRange();
for (const PartialDiagnosticAt &PDiag : EvaluationDiags)
S.Diag(PDiag.first, PDiag.second);
- return true;
+ return ExprError();
}
assert(EvalResult.Val.isInt() &&
Satisfaction.Details.emplace_back(ConstraintExpr,
SubstitutedAtomicExpr.get());
- return false;
+ return SubstitutedAtomicExpr;
}
-static bool calculateConstraintSatisfaction(
+static ExprResult calculateConstraintSatisfaction(
Sema &S, const NamedDecl *Template, SourceLocation TemplateNameLoc,
const MultiLevelTemplateArgumentList &MLTAL, const Expr *ConstraintExpr,
ConstraintSatisfaction &Satisfaction) {
return ExprError();
// We do not want error diagnostics escaping here.
Sema::SFINAETrap Trap(S);
- SubstitutedExpression = S.SubstExpr(const_cast<Expr *>(AtomicExpr),
- MLTAL);
+ SubstitutedExpression =
+ S.SubstConstraintExpr(const_cast<Expr *>(AtomicExpr), MLTAL);
// Substitution might have stripped off a contextual conversion to
// bool if this is the operand of an '&&' or '||'. For example, we
// might lose an lvalue-to-rvalue conversion here. If so, put it back
static bool CheckConstraintSatisfaction(
Sema &S, const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
+ llvm::SmallVectorImpl<Expr *> &Converted,
const MultiLevelTemplateArgumentList &TemplateArgsLists,
SourceRange TemplateIDRange, ConstraintSatisfaction &Satisfaction) {
if (ConstraintExprs.empty()) {
return true;
for (const Expr *ConstraintExpr : ConstraintExprs) {
- if (calculateConstraintSatisfaction(S, Template, TemplateIDRange.getBegin(),
- TemplateArgsLists, ConstraintExpr,
- Satisfaction))
+ ExprResult Res = calculateConstraintSatisfaction(
+ S, Template, TemplateIDRange.getBegin(), TemplateArgsLists,
+ ConstraintExpr, Satisfaction);
+ if (Res.isInvalid())
return true;
- if (!Satisfaction.IsSatisfied)
+
+ Converted.push_back(Res.get());
+ if (!Satisfaction.IsSatisfied) {
+ // Backfill the 'converted' list with nulls so we can keep the Converted
+ // and unconverted lists in sync.
+ Converted.append(ConstraintExprs.size() - Converted.size(), nullptr);
// [temp.constr.op] p2
- // [...] To determine if a conjunction is satisfied, the satisfaction
- // of the first operand is checked. If that is not satisfied, the
- // conjunction is not satisfied. [...]
+ // [...] To determine if a conjunction is satisfied, the satisfaction
+ // of the first operand is checked. If that is not satisfied, the
+ // conjunction is not satisfied. [...]
return false;
+ }
}
return false;
}
bool Sema::CheckConstraintSatisfaction(
const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
+ llvm::SmallVectorImpl<Expr *> &ConvertedConstraints,
const MultiLevelTemplateArgumentList &TemplateArgsLists,
SourceRange TemplateIDRange, ConstraintSatisfaction &OutSatisfaction) {
if (ConstraintExprs.empty()) {
return false;
}
if (!Template) {
- return ::CheckConstraintSatisfaction(*this, nullptr, ConstraintExprs,
- TemplateArgsLists, TemplateIDRange,
- OutSatisfaction);
+ return ::CheckConstraintSatisfaction(
+ *this, nullptr, ConstraintExprs, ConvertedConstraints,
+ TemplateArgsLists, TemplateIDRange, OutSatisfaction);
}
// A list of the template argument list flattened in a predictible manner for
auto Satisfaction =
std::make_unique<ConstraintSatisfaction>(Template, FlattenedArgs);
if (::CheckConstraintSatisfaction(*this, Template, ConstraintExprs,
- TemplateArgsLists, TemplateIDRange,
- *Satisfaction)) {
+ ConvertedConstraints, TemplateArgsLists,
+ TemplateIDRange, *Satisfaction)) {
return true;
}
OutSatisfaction = *Satisfaction;
bool Sema::CheckConstraintSatisfaction(const Expr *ConstraintExpr,
ConstraintSatisfaction &Satisfaction) {
return calculateConstraintSatisfaction(
- *this, ConstraintExpr, Satisfaction,
- [this](const Expr *AtomicExpr) -> ExprResult {
- // We only do this to immitate lvalue-to-rvalue conversion.
- return PerformContextuallyConvertToBool(const_cast<Expr *>(AtomicExpr));
- });
+ *this, ConstraintExpr, Satisfaction,
+ [this](const Expr *AtomicExpr) -> ExprResult {
+ // We only do this to immitate lvalue-to-rvalue conversion.
+ return PerformContextuallyConvertToBool(
+ const_cast<Expr *>(AtomicExpr));
+ })
+ .isInvalid();
+}
+
+bool Sema::SetupConstraintScope(
+ FunctionDecl *FD, llvm::Optional<ArrayRef<TemplateArgument>> TemplateArgs,
+ MultiLevelTemplateArgumentList MLTAL, LocalInstantiationScope &Scope) {
+ if (FD->isTemplateInstantiation() && FD->getPrimaryTemplate()) {
+ FunctionTemplateDecl *PrimaryTemplate = FD->getPrimaryTemplate();
+ InstantiatingTemplate Inst(
+ *this, FD->getPointOfInstantiation(),
+ Sema::InstantiatingTemplate::ConstraintsCheck{}, PrimaryTemplate,
+ TemplateArgs ? *TemplateArgs : ArrayRef<TemplateArgument>{},
+ SourceRange());
+ if (Inst.isInvalid())
+ return true;
+
+ // addInstantiatedParametersToScope creates a map of 'uninstantiated' to
+ // 'instantiated' parameters and adds it to the context. For the case where
+ // this function is a template being instantiated NOW, we also need to add
+ // the list of current template arguments to the list so that they also can
+ // be picked out of the map.
+ if (auto *SpecArgs = FD->getTemplateSpecializationArgs()) {
+ MultiLevelTemplateArgumentList JustTemplArgs(*SpecArgs);
+ if (addInstantiatedParametersToScope(
+ FD, PrimaryTemplate->getTemplatedDecl(), Scope, JustTemplArgs))
+ return true;
+ }
+
+ // If this is a member function, make sure we get the parameters that
+ // reference the original primary template.
+ if (const auto *FromMemTempl =
+ PrimaryTemplate->getInstantiatedFromMemberTemplate()) {
+ if (addInstantiatedParametersToScope(FD, FromMemTempl->getTemplatedDecl(),
+ Scope, MLTAL))
+ return true;
+ }
+
+ return false;
+ }
+
+ if (FD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization ||
+ FD->getTemplatedKind() == FunctionDecl::TK_DependentNonTemplate) {
+ FunctionDecl *InstantiatedFrom =
+ FD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization
+ ? FD->getInstantiatedFromMemberFunction()
+ : FD->getInstantiatedFromDecl();
+
+ InstantiatingTemplate Inst(
+ *this, FD->getPointOfInstantiation(),
+ Sema::InstantiatingTemplate::ConstraintsCheck{}, InstantiatedFrom,
+ TemplateArgs ? *TemplateArgs : ArrayRef<TemplateArgument>{},
+ SourceRange());
+ if (Inst.isInvalid())
+ return true;
+
+ // Case where this was not a template, but instantiated as a
+ // child-function.
+ if (addInstantiatedParametersToScope(FD, InstantiatedFrom, Scope, MLTAL))
+ return true;
+ }
+
+ return false;
+}
+
+// This function collects all of the template arguments for the purposes of
+// constraint-instantiation and checking.
+llvm::Optional<MultiLevelTemplateArgumentList>
+Sema::SetupConstraintCheckingTemplateArgumentsAndScope(
+ FunctionDecl *FD, llvm::Optional<ArrayRef<TemplateArgument>> TemplateArgs,
+ LocalInstantiationScope &Scope) {
+ MultiLevelTemplateArgumentList MLTAL;
+
+ // Collect the list of template arguments relative to the 'primary' template.
+ // We need the entire list, since the constraint is completely uninstantiated
+ // at this point.
+ MLTAL = getTemplateInstantiationArgs(FD, nullptr, /*RelativeToPrimary*/ true,
+ /*Pattern*/ nullptr,
+ /*LookBeyondLambda*/ true);
+ if (SetupConstraintScope(FD, TemplateArgs, MLTAL, Scope))
+ return {};
+
+ return MLTAL;
}
bool Sema::CheckFunctionConstraints(const FunctionDecl *FD,
ConstraintSatisfaction &Satisfaction,
- SourceLocation UsageLoc) {
- const Expr *RC = FD->getTrailingRequiresClause();
- if (RC->isInstantiationDependent()) {
+ SourceLocation UsageLoc,
+ bool ForOverloadResolution) {
+ // Don't check constraints if the function is dependent. Also don't check if
+ // this is a function template specialization, as the call to
+ // CheckinstantiatedFunctionTemplateConstraints after this will check it
+ // better.
+ if (FD->isDependentContext() ||
+ FD->getTemplatedKind() ==
+ FunctionDecl::TK_FunctionTemplateSpecialization) {
Satisfaction.IsSatisfied = true;
return false;
}
+
+ ContextRAII SavedContext{
+ *this, cast<DeclContext>(
+ const_cast<FunctionDecl *>(FD)->getNonClosureContext())};
+ LocalInstantiationScope Scope(*this, !ForOverloadResolution ||
+ isLambdaCallOperator(FD));
+ llvm::Optional<MultiLevelTemplateArgumentList> MLTAL =
+ SetupConstraintCheckingTemplateArgumentsAndScope(
+ const_cast<FunctionDecl *>(FD), {}, Scope);
+
Qualifiers ThisQuals;
CXXRecordDecl *Record = nullptr;
if (auto *Method = dyn_cast<CXXMethodDecl>(FD)) {
// We substitute with empty arguments in order to rebuild the atomic
// constraint in a constant-evaluated context.
// FIXME: Should this be a dedicated TreeTransform?
- return CheckConstraintSatisfaction(
- FD, {RC}, /*TemplateArgs=*/{},
- SourceRange(UsageLoc.isValid() ? UsageLoc : FD->getLocation()),
- Satisfaction);
+ const Expr *RC = FD->getTrailingRequiresClause();
+ llvm::SmallVector<Expr *, 1> Converted;
+
+ if (CheckConstraintSatisfaction(
+ FD, {RC}, Converted, *MLTAL,
+ SourceRange(UsageLoc.isValid() ? UsageLoc : FD->getLocation()),
+ Satisfaction))
+ return true;
+
+ // FIXME: we need to do this for the function constraints for
+ // comparison of constraints to work, but do we also need to do it for
+ // CheckInstantiatedFunctionConstraints? That one is more difficult, but we
+ // seem to always just pick up the constraints from the primary template.
+ assert(Converted.size() <= 1 && "Got more expressions converted?");
+ if (!Converted.empty() && Converted[0] != nullptr)
+ const_cast<FunctionDecl *>(FD)->setTrailingRequiresClause(Converted[0]);
+ return false;
}
bool Sema::EnsureTemplateArgumentListConstraints(
// PushDeclContext because we don't have a scope.
Sema::ContextRAII savedContext(*this, Decl);
LocalInstantiationScope Scope(*this);
- MultiLevelTemplateArgumentList MLTAL;
- // FIXME: This will be replaced with some logic to get all the template
- // arguments when we switch to deferred template instantiation.
- MLTAL.addOuterTemplateArguments(TemplateArgs);
-
- // If this is not an explicit specialization - we need to get the instantiated
- // version of the template arguments and add them to scope for the
- // substitution.
- if (Decl->isTemplateInstantiation()) {
- InstantiatingTemplate Inst(*this, Decl->getPointOfInstantiation(),
- InstantiatingTemplate::ConstraintsCheck{}, Decl->getPrimaryTemplate(),
- TemplateArgs, SourceRange());
- if (Inst.isInvalid())
- return true;
- MultiLevelTemplateArgumentList MLTAL(
- *Decl->getTemplateSpecializationArgs());
- if (addInstantiatedParametersToScope(
- Decl, Decl->getPrimaryTemplate()->getTemplatedDecl(), Scope, MLTAL))
- return true;
- }
+
+ Optional<MultiLevelTemplateArgumentList> MLTAL =
+ SetupConstraintCheckingTemplateArgumentsAndScope(Decl, TemplateArgs,
+ Scope);
+
+ if (!MLTAL)
+ return true;
+
Qualifiers ThisQuals;
CXXRecordDecl *Record = nullptr;
if (auto *Method = dyn_cast<CXXMethodDecl>(Decl)) {
Record = Method->getParent();
}
CXXThisScopeRAII ThisScope(*this, Record, ThisQuals, Record != nullptr);
- return CheckConstraintSatisfaction(Template, TemplateAC, MLTAL,
+ llvm::SmallVector<Expr *, 1> Converted;
+ return CheckConstraintSatisfaction(Template, TemplateAC, Converted, *MLTAL,
PointOfInstantiation, Satisfaction);
}
return CacheEntry->second;
}
-static bool substituteParameterMappings(Sema &S, NormalizedConstraint &N,
- ConceptDecl *Concept, ArrayRef<TemplateArgument> TemplateArgs,
- const ASTTemplateArgumentListInfo *ArgsAsWritten) {
+static bool
+substituteParameterMappings(Sema &S, NormalizedConstraint &N,
+ ConceptDecl *Concept,
+ const MultiLevelTemplateArgumentList &MLTAL,
+ const ASTTemplateArgumentListInfo *ArgsAsWritten) {
if (!N.isAtomic()) {
- if (substituteParameterMappings(S, N.getLHS(), Concept, TemplateArgs,
+ if (substituteParameterMappings(S, N.getLHS(), Concept, MLTAL,
ArgsAsWritten))
return true;
- return substituteParameterMappings(S, N.getRHS(), Concept, TemplateArgs,
+ return substituteParameterMappings(S, N.getRHS(), Concept, MLTAL,
ArgsAsWritten);
}
TemplateParameterList *TemplateParams = Concept->getTemplateParameters();
AtomicConstraint &Atomic = *N.getAtomicConstraint();
TemplateArgumentListInfo SubstArgs;
- MultiLevelTemplateArgumentList MLTAL;
- MLTAL.addOuterTemplateArguments(TemplateArgs);
if (!Atomic.ParameterMapping) {
llvm::SmallBitVector OccurringIndices(TemplateParams->size());
S.MarkUsedTemplateParameters(Atomic.ConstraintExpr, /*OnlyDeduced=*/false,
return false;
}
+static bool substituteParameterMappings(Sema &S, NormalizedConstraint &N,
+ const ConceptSpecializationExpr *CSE) {
+ TemplateArgumentList TAL{TemplateArgumentList::OnStack,
+ CSE->getTemplateArguments()};
+ MultiLevelTemplateArgumentList MLTAL =
+ S.getTemplateInstantiationArgs(CSE->getNamedConcept(), &TAL,
+ /*RelativeToPrimary*/ true,
+ /*Pattern*/ nullptr,
+ /*LookBeyondLambda*/ true);
+
+ return substituteParameterMappings(S, N, CSE->getNamedConcept(), MLTAL,
+ CSE->getTemplateArgsAsWritten());
+}
+
Optional<NormalizedConstraint>
NormalizedConstraint::fromConstraintExprs(Sema &S, NamedDecl *D,
ArrayRef<const Expr *> E) {
Optional<NormalizedConstraint> New;
New.emplace(S.Context, *SubNF);
- if (substituteParameterMappings(
- S, *New, CSE->getNamedConcept(),
- CSE->getTemplateArguments(), CSE->getTemplateArgsAsWritten()))
+ if (substituteParameterMappings(S, *New, CSE))
return None;
return New;
// definition.
if (FD->getTrailingRequiresClause()) {
ConstraintSatisfaction Satisfaction;
- if (CheckFunctionConstraints(FD, Satisfaction, Loc))
+ if (CheckFunctionConstraints(FD, Satisfaction, Loc,
+ /*ForOverloadResolution*/ true))
// A diagnostic will have already been generated (non-constant
// constraint expression, for example)
return true;
return false;
}
+// Figure out the to-translation-unit depth for this function declaration for
+// the purpose of seeing if they differ by constraints. This isn't the same as
+// getTemplateDepth, because it includes already instantiated parents.
+static unsigned CalculateTemplateDepthForConstraints(Sema &S,
+ FunctionDecl *FD) {
+ MultiLevelTemplateArgumentList MLTAL =
+ S.getTemplateInstantiationArgs(FD, nullptr, /*RelativeToPrimary*/ true,
+ /*Pattern*/ nullptr,
+ /*LookBeyondLambda*/ true);
+ return MLTAL.getNumSubstitutedLevels();
+}
+
+// Friend definitions can appear identical but be different declarations based
+// on the last sentence of the rule below (others included for clarification):
+// C++20 [temp.friend] p9: A non-template friend declaration
+// with a requires-clause shall be a definition. A friend function template
+// with a constraint that depends on a template parameter from an enclosing
+// template shall be a definition. Such a constrained friend function or
+// function template declaration does not declare the same function or function
+// template as a declaration in any other scope.
+static bool FriendsDifferByConstraints(Sema &S, DeclContext *CurContext,
+ FunctionDecl *Old, FunctionDecl *New,
+ Scope *Scope) {
+ // If these aren't friends, than they aren't friends that differe by
+ // constraints.
+ if (!Old->getFriendObjectKind() || !New->getFriendObjectKind())
+ return false;
+
+ // If the the two functions share lexical declaration context, they are not in
+ // separate instantations, and thus in the same scope.
+ if (New->getLexicalDeclContext() == Old->getLexicalDeclContext())
+ return false;
+
+ if (!Old->getDescribedFunctionTemplate()) {
+ assert(!New->getDescribedFunctionTemplate() &&
+ "How would these be the same if they aren't both templates?");
+
+ // If these friends don't have constraints, they aren't constrained, and
+ // thus don't fall under temp.friend p9. Else the simple presence of a
+ // constraint makes them unique.
+ return Old->getTrailingRequiresClause();
+ }
+
+ SmallVector<const Expr *, 3> OldAC;
+ Old->getDescribedFunctionTemplate()->getAssociatedConstraints(OldAC);
+
+#ifndef NDEBUG
+ SmallVector<const Expr *, 3> NewAC;
+ New->getDescribedFunctionTemplate()->getAssociatedConstraints(NewAC);
+ assert(OldAC.size() == NewAC.size() &&
+ "Difference should have been noticed earlier if sizes of constraints "
+ "aren't the same");
+#endif
+ // If there are no constraints, these are not constrained friend function or
+ // friend function templates.
+ if (OldAC.size() == 0)
+ return false;
+
+ unsigned OldTemplateDepth = CalculateTemplateDepthForConstraints(S, Old);
+
+ // At this point, if the constrained function template declaration depends on
+ // a template parameter from an enclosing template, they are not the same
+ // function. Since these were deemed identical before we got here, we only
+ // have to look into 1 side to see if they refer to a containing template.
+ for (const Expr *Constraint : OldAC)
+ if (S.ConstraintExpressionDependsOnEnclosingTemplate(OldTemplateDepth,
+ Constraint))
+ return true;
+
+ return false;
+}
+
/// Determine whether the given New declaration is an overload of the
/// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if
/// New and Old cannot be overloaded, e.g., if New has the same signature as
!shouldLinkPossiblyHiddenDecl(*I, New))
continue;
+ // C++20 [temp.friend] p9: A non-template friend declaration with a
+ // requires-clause shall be a definition. A friend function template
+ // with a constraint that depends on a template parameter from an
+ // enclosing template shall be a definition. Such a constrained friend
+ // function or function template declaration does not declare the same
+ // function or function template as a declaration in any other scope.
+ if (FriendsDifferByConstraints(*this, CurContext, OldF, New, S))
+ continue;
+
Match = *I;
return Ovl_Match;
}
if (Function->getTrailingRequiresClause()) {
ConstraintSatisfaction Satisfaction;
- if (CheckFunctionConstraints(Function, Satisfaction) ||
+ if (CheckFunctionConstraints(Function, Satisfaction, /*Loc*/ {},
+ /*ForOverloadResolution*/ true) ||
!Satisfaction.IsSatisfied) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_constraints_not_satisfied;
if (Method->getTrailingRequiresClause()) {
ConstraintSatisfaction Satisfaction;
- if (CheckFunctionConstraints(Method, Satisfaction) ||
+ if (CheckFunctionConstraints(Method, Satisfaction, /*Loc*/ {},
+ /*ForOverloadResolution*/ true) ||
!Satisfaction.IsSatisfied) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_constraints_not_satisfied;
return Param;
}
+namespace {
+class ConstraintRefersToContainingTemplateChecker
+ : public TreeTransform<ConstraintRefersToContainingTemplateChecker> {
+ bool Result = false;
+ unsigned TemplateDepth = 0;
+
+public:
+ using inherited = TreeTransform<ConstraintRefersToContainingTemplateChecker>;
+
+ ConstraintRefersToContainingTemplateChecker(Sema &SemaRef,
+ unsigned TemplateDepth)
+ : inherited(SemaRef), TemplateDepth(TemplateDepth) {}
+ bool getResult() const { return Result; }
+
+ // This should be the only template parm type that we have to deal with.
+ // SubstTempalteTypeParmPack, SubstNonTypeTemplateParmPack, and
+ // FunctionParmPackExpr are all partially substituted, which cannot happen
+ // with concepts at this point in translation.
+ QualType TransformTemplateTypeParmType(TypeLocBuilder &TLB,
+ TemplateTypeParmTypeLoc TL) {
+ assert(TL.getDecl()->getDepth() <= TemplateDepth &&
+ "Nothing should reference a value below the actual template depth, "
+ "depth is likely wrong");
+ if (TL.getDecl()->getDepth() != TemplateDepth)
+ Result = true;
+ return inherited::TransformTemplateTypeParmType(TLB, TL);
+ }
+
+ Decl *TransformDecl(SourceLocation Loc, Decl *D) {
+ // FIXME : This is possibly an incomplete list, but it is unclear what other
+ // Decl kinds could be used to refer to the template parameters. This is a
+ // best guess so far based on examples currently available, but the
+ // unreachable should catch future instances/cases.
+ if (auto *TD = dyn_cast<TypedefNameDecl>(D))
+ TransformType(TD->getUnderlyingType());
+ else if (auto *VD = dyn_cast<ValueDecl>(D))
+ TransformType(VD->getType());
+ else if (auto *TD = dyn_cast<TemplateDecl>(D))
+ TransformTemplateParameterList(TD->getTemplateParameters());
+ else
+ llvm_unreachable("Don't know how to handle this declaration type yet");
+ return D;
+ }
+};
+} // namespace
+
+bool Sema::ConstraintExpressionDependsOnEnclosingTemplate(
+ unsigned TemplateDepth, const Expr *Constraint) {
+ ConstraintRefersToContainingTemplateChecker Checker(*this, TemplateDepth);
+ Checker.TransformExpr(const_cast<Expr *>(Constraint));
+ return Checker.getResult();
+}
+
/// ActOnTemplateParameterList - Builds a TemplateParameterList, optionally
/// constrained by RequiresClause, that contains the template parameters in
/// Params.
TTP->isExpandedParameterPack() ?
llvm::Optional<unsigned>(TTP->getNumExpansionParameters()) : None);
if (const auto *TC = TTP->getTypeConstraint())
- SemaRef.SubstTypeConstraint(NewTTP, TC, Args);
+ SemaRef.SubstTypeConstraint(NewTTP, TC, Args,
+ /*EvaluateConstraint*/ true);
if (TTP->hasDefaultArgument()) {
TypeSourceInfo *InstantiatedDefaultArg =
SemaRef.SubstType(TTP->getDefaultArgumentInfo(), Args,
TemplateArgs = std::move(NewArgs);
if (!PartialTemplateArgs) {
- // FIXME: This will be changed a bit once deferred concept instantiation is
- // implemented.
- MultiLevelTemplateArgumentList MLTAL;
- MLTAL.addOuterTemplateArguments(Converted);
+ TemplateArgumentList StackTemplateArgs(TemplateArgumentList::OnStack,
+ Converted);
+ MultiLevelTemplateArgumentList MLTAL = getTemplateInstantiationArgs(
+ Template, &StackTemplateArgs, /*RelativeToPrimary*/ true,
+ /*Pattern*/ nullptr,
+ /*LookBeyondLambda*/ true, /*IncludeContainingStruct*/ true);
if (EnsureTemplateArgumentListConstraints(
Template, MLTAL,
SourceRange(TemplateLoc, TemplateArgs.getRAngleLoc()))) {
// are not considered.
if (ParamsAC.empty())
return false;
+
Template->getAssociatedConstraints(TemplateAC);
+
bool IsParamAtLeastAsConstrained;
if (IsAtLeastAsConstrained(Param, ParamsAC, Template, TemplateAC,
IsParamAtLeastAsConstrained))
struct IsPartialSpecialization<VarTemplatePartialSpecializationDecl> {
static constexpr bool value = true;
};
+template <typename TemplateDeclT>
+static bool DeducedArgsNeedReplacement(TemplateDeclT *Template) {
+ return false;
+}
+template <>
+bool DeducedArgsNeedReplacement<VarTemplatePartialSpecializationDecl>(
+ VarTemplatePartialSpecializationDecl *Spec) {
+ return !Spec->isClassScopeExplicitSpecialization();
+}
+template <>
+bool DeducedArgsNeedReplacement<ClassTemplatePartialSpecializationDecl>(
+ ClassTemplatePartialSpecializationDecl *Spec) {
+ return !Spec->isClassScopeExplicitSpecialization();
+}
template<typename TemplateDeclT>
static Sema::TemplateDeductionResult
TemplateDeductionInfo& Info) {
llvm::SmallVector<const Expr *, 3> AssociatedConstraints;
Template->getAssociatedConstraints(AssociatedConstraints);
- // FIXME: This will change quite a bit once deferred concept instantiation is
- // implemented.
MultiLevelTemplateArgumentList MLTAL;
- MLTAL.addOuterTemplateArguments(DeducedArgs);
- if (S.CheckConstraintSatisfaction(Template, AssociatedConstraints,
- MLTAL, Info.getLocation(),
+ bool NeedsReplacement = DeducedArgsNeedReplacement(Template);
+ TemplateArgumentList DeducedTAL{TemplateArgumentList::OnStack, DeducedArgs};
+
+ MLTAL = S.getTemplateInstantiationArgs(
+ Template, /*InnerMost*/ NeedsReplacement ? nullptr : &DeducedTAL,
+ /*RelativeToPrimary*/ true, /*Pattern*/
+ nullptr, /*LookBeyondLambda*/ true);
+
+ // getTemplateInstantiationArgs picks up the non-deduced version of the
+ // template args when this is a variable template partial specialization and
+ // not class-scope explicit specialization, so replace with Deduced Args
+ // instead of adding to inner-most.
+ if (NeedsReplacement)
+ MLTAL.replaceInnermostTemplateArguments(DeducedArgs);
+
+ if (S.CheckConstraintSatisfaction(Template, AssociatedConstraints, MLTAL,
+ Info.getLocation(),
Info.AssociatedConstraintsSatisfaction) ||
!Info.AssociatedConstraintsSatisfaction.IsSatisfied) {
Info.reset(TemplateArgumentList::CreateCopy(S.Context, DeducedArgs));
/// instantiating the definition of the given declaration, \p D. This is
/// used to determine the proper set of template instantiation arguments for
/// friend function template specializations.
+///
+/// \param LookBeyondLambda Indicates that this collection of arguments should
+/// continue looking when it encounters a lambda generic call operator.
+///
+/// \param IncludeContainingStructArgs Indicates that this collection of
+/// arguments should include arguments for any class template that this
+/// declaration is included inside of.
+
MultiLevelTemplateArgumentList Sema::getTemplateInstantiationArgs(
const NamedDecl *D, const TemplateArgumentList *Innermost,
- bool RelativeToPrimary, const FunctionDecl *Pattern) {
+ bool RelativeToPrimary, const FunctionDecl *Pattern, bool LookBeyondLambda,
+ bool IncludeContainingStructArgs) {
// Accumulate the set of template argument lists in this structure.
MultiLevelTemplateArgumentList Result;
break;
// If this function is a generic lambda specialization, we are done.
- if (isGenericLambdaCallOperatorOrStaticInvokerSpecialization(Function))
+ if (!LookBeyondLambda &&
+ isGenericLambdaCallOperatorOrStaticInvokerSpecialization(Function))
break;
} else if (Function->getDescribedFunctionTemplate()) {
- assert(Result.getNumSubstitutedLevels() == 0 &&
+ assert((IncludeContainingStructArgs ||
+ Result.getNumSubstitutedLevels() == 0) &&
"Outer template not instantiated?");
}
}
} else if (const auto *Rec = dyn_cast<CXXRecordDecl>(Ctx)) {
if (ClassTemplateDecl *ClassTemplate = Rec->getDescribedClassTemplate()) {
- assert(Result.getNumSubstitutedLevels() == 0 &&
+ assert((IncludeContainingStructArgs ||
+ Result.getNumSubstitutedLevels() == 0) &&
"Outer template not instantiated?");
if (ClassTemplate->isMemberSpecialization())
break;
+ if (IncludeContainingStructArgs) {
+ QualType RecordType = Context.getTypeDeclType(Rec);
+ QualType Injected = cast<InjectedClassNameType>(RecordType)
+ ->getInjectedSpecializationType();
+ const auto *InjectedType = cast<TemplateSpecializationType>(Injected);
+ Result.addOuterTemplateArguments(InjectedType->template_arguments());
+ }
}
}
const MultiLevelTemplateArgumentList &TemplateArgs;
SourceLocation Loc;
DeclarationName Entity;
+ bool EvaluateConstraints = true;
public:
typedef TreeTransform<TemplateInstantiator> inherited;
TemplateInstantiator(Sema &SemaRef,
const MultiLevelTemplateArgumentList &TemplateArgs,
- SourceLocation Loc,
- DeclarationName Entity)
- : inherited(SemaRef), TemplateArgs(TemplateArgs), Loc(Loc),
- Entity(Entity) { }
+ SourceLocation Loc, DeclarationName Entity)
+ : inherited(SemaRef), TemplateArgs(TemplateArgs), Loc(Loc),
+ Entity(Entity) {}
+
+ void setEvaluateConstraints(bool B) {
+ EvaluateConstraints = B;
+ }
+ bool getEvaluateConstraints() {
+ return EvaluateConstraints;
+ }
/// Determine whether the given type \p T has already been
/// transformed.
ExprResult TransformLambdaExpr(LambdaExpr *E) {
LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
- return inherited::TransformLambdaExpr(E);
+ Sema::ConstraintEvalRAII<TemplateInstantiator> RAII(*this);
+ ExprResult Res = inherited::TransformLambdaExpr(E);
+ return Res;
}
ExprResult TransformRequiresExpr(RequiresExpr *E) {
DeclContext *Owner = OrigTPL->getParam(0)->getDeclContext();
TemplateDeclInstantiator DeclInstantiator(getSema(),
/* DeclContext *Owner */ Owner, TemplateArgs);
+ DeclInstantiator.setEvaluateConstraints(EvaluateConstraints);
return DeclInstantiator.SubstTemplateParams(OrigTPL);
}
int indexAdjustment,
Optional<unsigned> NumExpansions,
bool ExpectParameterPack) {
- auto NewParm =
- SemaRef.SubstParmVarDecl(OldParm, TemplateArgs, indexAdjustment,
- NumExpansions, ExpectParameterPack);
+ auto NewParm = SemaRef.SubstParmVarDecl(
+ OldParm, TemplateArgs, indexAdjustment, NumExpansions,
+ ExpectParameterPack, EvaluateConstraints);
if (NewParm && SemaRef.getLangOpts().OpenCL)
SemaRef.deduceOpenCLAddressSpace(NewParm);
return NewParm;
Req, Info, OrigTPL->getSourceRange());
if (TPLInst.isInvalid())
return nullptr;
- TemplateParameterList *TPL =
- TransformTemplateParameterList(OrigTPL);
+ TemplateParameterList *TPL = TransformTemplateParameterList(OrigTPL);
if (!TPL)
TransRetReq.emplace(createSubstDiag(SemaRef, Info,
[&] (llvm::raw_ostream& OS) {
SourceLocation Loc,
DeclarationName Entity,
CXXRecordDecl *ThisContext,
- Qualifiers ThisTypeQuals) {
+ Qualifiers ThisTypeQuals,
+ bool EvaluateConstraints) {
assert(!CodeSynthesisContexts.empty() &&
"Cannot perform an instantiation without some context on the "
"instantiation stack");
return T;
TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
+ Instantiator.setEvaluateConstraints(EvaluateConstraints);
TypeLocBuilder TLB;
bool Sema::SubstTypeConstraint(
TemplateTypeParmDecl *Inst, const TypeConstraint *TC,
- const MultiLevelTemplateArgumentList &TemplateArgs) {
+ const MultiLevelTemplateArgumentList &TemplateArgs,
+ bool EvaluateConstraints) {
const ASTTemplateArgumentListInfo *TemplArgInfo =
TC->getTemplateArgsAsWritten();
+
+ if (!EvaluateConstraints) {
+ Inst->setTypeConstraint(TC->getNestedNameSpecifierLoc(),
+ TC->getConceptNameInfo(), TC->getNamedConcept(),
+ TC->getNamedConcept(), TemplArgInfo,
+ TC->getImmediatelyDeclaredConstraint());
+ return false;
+ }
+
TemplateArgumentListInfo InstArgs;
if (TemplArgInfo) {
: SourceLocation());
}
-ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
- const MultiLevelTemplateArgumentList &TemplateArgs,
- int indexAdjustment,
- Optional<unsigned> NumExpansions,
- bool ExpectParameterPack) {
+ParmVarDecl *
+Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
+ const MultiLevelTemplateArgumentList &TemplateArgs,
+ int indexAdjustment, Optional<unsigned> NumExpansions,
+ bool ExpectParameterPack, bool EvaluateConstraint) {
TypeSourceInfo *OldDI = OldParm->getTypeSourceInfo();
TypeSourceInfo *NewDI = nullptr;
// template's described function, but we might also get here later.
// Make sure we do not instantiate the TypeConstraint more than once.
if (Inst && !Inst->getTypeConstraint()) {
- // TODO: Concepts: do not instantiate the constraint (delayed constraint
- // substitution)
- if (SubstTypeConstraint(Inst, TC, TemplateArgs))
+ if (SubstTypeConstraint(Inst, TC, TemplateArgs, EvaluateConstraint))
return nullptr;
}
}
ArrayRef<TemplateArgumentLoc> Args,
const MultiLevelTemplateArgumentList &TemplateArgs,
TemplateArgumentListInfo &Out) {
- TemplateInstantiator Instantiator(*this, TemplateArgs,
- SourceLocation(),
+ TemplateInstantiator Instantiator(*this, TemplateArgs, SourceLocation(),
DeclarationName());
- return Instantiator.TransformTemplateArguments(Args.begin(), Args.end(),
- Out);
+ return Instantiator.TransformTemplateArguments(Args.begin(), Args.end(), Out);
}
ExprResult
return Instantiator.TransformExpr(E);
}
+ExprResult
+Sema::SubstConstraintExpr(Expr *E,
+ const MultiLevelTemplateArgumentList &TemplateArgs) {
+ if (!E)
+ return E;
+
+ // This is where we need to make sure we 'know' constraint checking needs to
+ // happen.
+ TemplateInstantiator Instantiator(*this, TemplateArgs, SourceLocation(),
+ DeclarationName());
+ return Instantiator.TransformExpr(E);
+}
+
ExprResult Sema::SubstInitializer(Expr *Init,
const MultiLevelTemplateArgumentList &TemplateArgs,
bool CXXDirectInit) {
- TemplateInstantiator Instantiator(*this, TemplateArgs,
- SourceLocation(),
+ TemplateInstantiator Instantiator(*this, TemplateArgs, SourceLocation(),
DeclarationName());
return Instantiator.TransformInitializer(Init, CXXDirectInit);
}
// merged with the local instantiation scope for the function template
// itself.
LocalInstantiationScope Scope(SemaRef);
+ Sema::ConstraintEvalRAII<TemplateDeclInstantiator> RAII(*this);
TemplateParameterList *TempParams = D->getTemplateParameters();
TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
return nullptr;
}
- // FIXME: Concepts: Do not substitute into constraint expressions
Expr *TrailingRequiresClause = D->getTrailingRequiresClause();
- if (TrailingRequiresClause) {
- EnterExpressionEvaluationContext ConstantEvaluated(
- SemaRef, Sema::ExpressionEvaluationContext::Unevaluated);
- ExprResult SubstRC = SemaRef.SubstExpr(TrailingRequiresClause,
- TemplateArgs);
- if (SubstRC.isInvalid())
- return nullptr;
- TrailingRequiresClause = SubstRC.get();
- if (!SemaRef.CheckConstraintExpression(TrailingRequiresClause))
- return nullptr;
- }
// If we're instantiating a local function declaration, put the result
// in the enclosing namespace; otherwise we need to find the instantiated
return nullptr;
}
- // FIXME: Concepts: Do not substitute into constraint expressions
- Expr *TrailingRequiresClause = D->getTrailingRequiresClause();
- if (TrailingRequiresClause) {
- EnterExpressionEvaluationContext ConstantEvaluated(
- SemaRef, Sema::ExpressionEvaluationContext::Unevaluated);
- auto *ThisContext = dyn_cast_or_null<CXXRecordDecl>(Owner);
- Sema::CXXThisScopeRAII ThisScope(SemaRef, ThisContext,
- D->getMethodQualifiers(), ThisContext);
- ExprResult SubstRC = SemaRef.SubstExpr(TrailingRequiresClause,
- TemplateArgs);
- if (SubstRC.isInvalid())
- return nullptr;
- TrailingRequiresClause = SubstRC.get();
- if (!SemaRef.CheckConstraintExpression(TrailingRequiresClause))
- return nullptr;
- }
-
DeclContext *DC = Owner;
if (isFriend) {
if (QualifierLoc) {
if (!DC) return nullptr;
}
+ CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
+ Expr *TrailingRequiresClause = D->getTrailingRequiresClause();
+
DeclarationNameInfo NameInfo
= SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
adjustForRewrite(FunctionRewriteKind, D, T, TInfo, NameInfo);
// Build the instantiated method declaration.
- CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
CXXMethodDecl *Method = nullptr;
SourceLocation StartLoc = D->getInnerLocStart();
Inst->setImplicit(D->isImplicit());
if (auto *TC = D->getTypeConstraint()) {
if (!D->isImplicit()) {
- // Invented template parameter type constraints will be instantiated with
- // the corresponding auto-typed parameter as it might reference other
- // parameters.
-
- // TODO: Concepts: do not instantiate the constraint (delayed constraint
- // substitution)
- if (SemaRef.SubstTypeConstraint(Inst, TC, TemplateArgs))
+ // Invented template parameter type constraints will be instantiated
+ // with the corresponding auto-typed parameter as it might reference
+ // other parameters.
+ if (SemaRef.SubstTypeConstraint(Inst, TC, TemplateArgs,
+ EvaluateConstraints))
return nullptr;
}
}
if (Invalid)
return nullptr;
- // FIXME: Concepts: Substitution into requires clause should only happen when
- // checking satisfaction.
- Expr *InstRequiresClause = nullptr;
- if (Expr *E = L->getRequiresClause()) {
- EnterExpressionEvaluationContext ConstantEvaluated(
- SemaRef, Sema::ExpressionEvaluationContext::Unevaluated);
- ExprResult Res = SemaRef.SubstExpr(E, TemplateArgs);
- if (Res.isInvalid() || !Res.isUsable()) {
- return nullptr;
- }
- InstRequiresClause = Res.get();
- }
+ Expr *InstRequiresClause = L->getRequiresClause();
TemplateParameterList *InstL
= TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
ThisTypeQuals = Method->getMethodQualifiers();
}
- TypeSourceInfo *NewTInfo
- = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
- D->getTypeSpecStartLoc(),
- D->getDeclName(),
- ThisContext, ThisTypeQuals);
+ TypeSourceInfo *NewTInfo = SemaRef.SubstFunctionDeclType(
+ OldTInfo, TemplateArgs, D->getTypeSpecStartLoc(), D->getDeclName(),
+ ThisContext, ThisTypeQuals, EvaluateConstraints);
if (!NewTInfo)
return nullptr;
NewCallOpType);
}
- // Transform the trailing requires clause
- ExprResult NewTrailingRequiresClause;
- if (Expr *TRC = E->getCallOperator()->getTrailingRequiresClause())
- // FIXME: Concepts: Substitution into requires clause should only happen
- // when checking satisfaction.
- NewTrailingRequiresClause = getDerived().TransformExpr(TRC);
-
// Create the local class that will describe the lambda.
// FIXME: DependencyKind below is wrong when substituting inside a templated
E->getCallOperator()->getEndLoc(),
NewCallOpTSI->getTypeLoc().castAs<FunctionProtoTypeLoc>().getParams(),
E->getCallOperator()->getConstexprKind(),
- NewTrailingRequiresClause.get());
+ E->getCallOperator()->getTrailingRequiresClause());
LSI->CallOperator = NewCallOperator;
static_assert(C<int>{}); // expected-note{{while checking constraint satisfaction for template 'C<int>' required here}}
static_assert(D<int>{}); // expected-note{{while checking constraint satisfaction for template 'D<int>' required here}}
+
+// Test the delayed instantiation, the 'foo' implementation shouldn't cause the
+// constraint failure(or crash!) until the use to create 'y'.
+namespace DelayedInst {
+template <unsigned I>
+struct AAA {
+ template <typename T>
+ requires(sizeof(T) == I) // expected-note {{because 'sizeof(int) == 5U' (4 == 5) evaluated to false}}
+ struct B {
+ static constexpr int a = 0;
+ };
+
+ static constexpr auto foo() {
+ return B<int>::a; // expected-error{{constraints not satisfied for class template 'B' [with T = int]}}
+ }
+};
+
+constexpr auto x = AAA<4>::foo();
+constexpr auto y = AAA<5>::foo(); // expected-note {{in instantiation of member function 'DelayedInst::AAA<5>::foo' requested here}}
+
+} // namespace DelayedInst
static_assert(F<char[10]>::value == 3);
static_assert(F<char>::value == 1);
+template <unsigned I>
+struct S {
+ template <typename T>
+ struct F {
+ enum { value = 1 };
+ };
+
+ template <typename T>
+ requires C1<T> && C2<T>
+ struct F<T> {
+ enum { value = 2 };
+ };
+
+ template <typename T>
+ requires C1<T> || C2<T>
+ struct F<T> {
+ enum { value = 3 };
+ };
+};
+
+static_assert(S<1>::F<unsigned>::value == 2);
+static_assert(S<1>::F<char[10]>::value == 3);
+static_assert(S<1>::F<char>::value == 1);
+
// Make sure atomic constraints subsume each other only if their parameter
// mappings are identical.
static_assert(f<char[10]> == 3);
static_assert(f<char> == 1);
-
-
+template <int I>
+struct S {
+ template <typename T>
+ static constexpr int f = 1;
+
+ template <typename T>
+ requires C1<T> && C2<T>
+ static constexpr int f<T> = 2;
+
+ template <typename T>
+ requires C1<T> || C2<T>
+ static constexpr int f<T> = 3;
+};
+
+static_assert(S<1>::f<unsigned> == 2);
+static_assert(S<1>::f<char[10]> == 3);
+static_assert(S<1>::f<char> == 1);
--- /dev/null
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify %s
+
+template <typename T>
+concept constraint = false;
+namespace temp_friend_9 {
+// A non-template friend declaration with a requires-clause shall be a
+// definition. ...Such a constrained friend function ... does not declare the
+// same function or function template as a declaration in any other scope.
+template <typename T>
+struct NonTemplateFriend {
+ friend void foo()
+ requires true
+ {}
+};
+
+// A friend function template with a constraint that depends on a template
+// parameter from an enclosing template shall be a definition. Such a ...
+// function template declaration does not declare the same function or
+// function template as a declaration in any other scope.
+template <typename T>
+struct TemplateFromEnclosing {
+ template <typename U>
+ friend void foo()
+ requires constraint<T>
+ {}
+
+ T variable;
+ template <typename U>
+ friend void foo2()
+ requires constraint<decltype(variable)>
+ {}
+
+ template <typename U>
+ friend void foo3(T parmvar)
+ requires constraint<decltype(parmvar)>
+ {}
+
+ template <typename U>
+ friend void foo4()
+ requires requires(T &req) { (void)req; }
+ {}
+
+ using Alias = T;
+ template <typename U>
+ friend void foo5()
+ requires constraint<Alias>
+ {}
+
+ // All of these refer to a parent, so these are not duplicate definitions.
+ struct ChildOfEnclosing {
+ template <typename U>
+ friend void foo6()
+ requires constraint<T>
+ {}
+ template <typename U>
+ friend void foo7()
+ requires constraint<decltype(variable)>
+ {}
+ template <typename U>
+ friend void foo8(T parmvar)
+ requires constraint<decltype(parmvar)>
+ {}
+ // This is NOT a duplicate since it itself is not a template.
+ friend void foo9()
+ requires true
+ {}
+ };
+ template <typename T2>
+ struct TemplChildOfEnclosing {
+ template <typename U>
+ friend void foo10()
+ requires constraint<T>
+ {}
+ };
+};
+
+// Doesn't meet either of the requirements in the above as they don't refer to
+// an enclosing scope.
+template <typename T>
+struct Redefinition {
+ template <typename U>
+ friend void foo() // #REDEF
+ requires constraint<U>
+ {}
+
+ struct ChildOfRedef {
+ template <typename U>
+ friend void foo2() // #REDEF2
+ requires constraint<U>
+ {}
+ };
+ template <typename T2>
+ struct ChildOfRedef2 {
+ template <typename U>
+ friend void foo3() // #REDEF3
+ requires constraint<U>
+ {}
+ };
+};
+
+void bar() {
+ NonTemplateFriend<int> S1;
+ NonTemplateFriend<float> S2;
+ TemplateFromEnclosing<int> S3;
+ TemplateFromEnclosing<int>::ChildOfEnclosing S3b;
+ TemplateFromEnclosing<float> S4;
+ TemplateFromEnclosing<float>::ChildOfEnclosing S4b;
+ Redefinition<int> S5;
+ Redefinition<float> S6;
+ // expected-error@#REDEF {{redefinition of 'foo'}}
+ // expected-note@-2{{in instantiation of template class }}
+ // expected-note@#REDEF {{previous definition is here}}
+ Redefinition<int>::ChildOfRedef S7;
+ Redefinition<float>::ChildOfRedef S8;
+ // expected-error@#REDEF2 {{redefinition of 'foo2'}}
+ // expected-note@-2{{in instantiation of member class }}
+ // expected-note@#REDEF2 {{previous definition is here}}
+
+ Redefinition<int>::ChildOfRedef2<int> S9;
+ Redefinition<float>::ChildOfRedef2<float> S10;
+ // expected-error@#REDEF3 {{redefinition of 'foo3'}}
+ // expected-note@-2{{in instantiation of template class }}
+ // expected-note@#REDEF3 {{previous definition is here}}
+}
+} // namespace temp_friend_9
+
+namespace SameScopeRedefs {
+template <typename T>
+struct NonTemplateFriend {
+ friend void foo() // #NTF1
+ requires true
+ {}
+ friend void foo() // #NTF2
+ requires true
+ {}
+};
+
+template <typename T>
+struct TemplateFromEnclosing {
+ template <typename U>
+ friend void foo() // #TFE1
+ requires constraint<T>
+ {}
+ template <typename U>
+ friend void foo() // #TFE2
+ requires constraint<T>
+ {}
+};
+// Same as above, but doesn't require an instantiation pair to cause.
+template <typename T>
+struct Redefinition {
+ template <typename U>
+ friend void foo() // #RD1
+ requires constraint<U>
+ {}
+ template <typename U>
+ friend void foo() // #RD2
+ requires constraint<U>
+ {}
+};
+void bar() {
+ NonTemplateFriend<int> S1;
+ // expected-error@#NTF2 {{redefinition of 'foo'}}
+ // expected-note@-2{{in instantiation of template class}}
+ // expected-note@#NTF1 {{previous definition is here}}
+
+ TemplateFromEnclosing<int> S2;
+ // expected-error@#TFE2 {{redefinition of 'foo'}}
+ // expected-note@-2{{in instantiation of template class}}
+ // expected-note@#TFE1 {{previous definition is here}}
+
+ Redefinition<int> S3;
+ // expected-error@#RD2 {{redefinition of 'foo'}}
+ // expected-note@-2{{in instantiation of template class}}
+ // expected-note@#RD1 {{previous definition is here}}
+}
+} // namespace SameScopeRedefs
+
+namespace LibCXXOperatorRedef {
+template <typename T, typename U> struct is_same {
+ static constexpr bool value = false;
+};
+template <typename T> struct is_same<T, T> {
+ static constexpr bool value = false;
+};
+
+template <typename T, typename U>
+concept same_as = is_same<T, U>::value;
+
+// An issue found from libcxx when trying to commit the deferred concepts patch.
+// This caused an error of 'redefinition of funcN'.
+template <class _Tp> struct __range_adaptor_closure {
+ template <typename _View, typename _Closure>
+ requires same_as<_Tp, _Closure>
+ friend constexpr decltype(auto) R1func1(_View &&__view,
+ _Closure &&__closure){};
+ template <typename _View, typename _Closure>
+ friend constexpr decltype(auto) R1func2(_View &&__view,
+ _Closure &&__closure)
+ requires same_as<_Tp, _Closure>
+ {};
+ template <same_as<_Tp> _View, typename _Closure>
+ friend constexpr decltype(auto) R1func3(_View &&__view,
+ _Closure &&__closure){};
+};
+
+struct A : __range_adaptor_closure<A> {};
+struct B : __range_adaptor_closure<B> {};
+
+// These three fail because after the 1st pass of instantiation, they are still
+// identical.
+template <class _Tp> struct __range_adaptor_closure2 {
+ template <typename _View, typename _Closure>
+ requires same_as<_View, _Closure>
+ friend constexpr decltype(auto) R2func1(_View &&__view, // #FUNC1
+ _Closure &&__closure){};
+ template <typename _View, typename _Closure>
+ friend constexpr decltype(auto) R2func2(_View &&__view, // #FUNC2
+ _Closure &&__closure)
+ requires same_as<_View, _Closure>
+ {};
+ template <typename _View, same_as<_View> _Closure>
+ friend constexpr decltype(auto) R2func3(_View &&__view, // #FUNC3
+ _Closure &&__closure){};
+};
+
+struct A2 : __range_adaptor_closure2<A2> {};
+struct B2 : __range_adaptor_closure2<B2> {};
+// expected-error@#FUNC1{{redefinition of 'R2func1'}}
+// expected-note@-2{{in instantiation of template class}}
+// expected-note@#FUNC1{{previous definition is here}}
+// expected-error@#FUNC2{{redefinition of 'R2func2'}}
+// expected-note@#FUNC2{{previous definition is here}}
+// expected-error@#FUNC3{{redefinition of 'R2func3'}}
+// expected-note@#FUNC3{{previous definition is here}}
+
+// These three are fine, they all depend on the parent template parameter, so
+// are different despite ::type not being valid.
+template <class _Tp> struct __range_adaptor_closure3 {
+ template <typename _View, typename _Closure>
+ requires same_as<typename _Tp::type, _Closure>
+ friend constexpr decltype(auto) R3func1(_View &&__view,
+ _Closure &&__closure){};
+ template <typename _View, typename _Closure>
+ friend constexpr decltype(auto) R3func2(_View &&__view,
+ _Closure &&__closure)
+ requires same_as<typename _Tp::type, _Closure>
+ {};
+ template <same_as<typename _Tp::type> _View, typename _Closure>
+ friend constexpr decltype(auto) R3func3(_View &&__view,
+ _Closure &&__closure){};
+};
+
+struct A3 : __range_adaptor_closure3<A3> {};
+struct B3 : __range_adaptor_closure3<B3> {};
+
+template <class _Tp> struct __range_adaptor_closure4 {
+ template <typename _View, typename _Closure>
+ requires same_as<_Tp, _View>
+ // expected-note@+1{{previous definition is here}}
+ void foo1(_View &&, _Closure &&) {}
+ template <typename _View, typename _Closure>
+ requires same_as<_Tp, _View>
+ // expected-error@+1{{class member cannot be redeclared}}
+ void foo1(_View &&, _Closure &&) {}
+
+ template <typename _View, typename _Closure>
+ // expected-note@+1{{previous definition is here}}
+ void foo2(_View &&, _Closure &&)
+ requires same_as<_Tp, _View>
+ {}
+ template <typename _View, typename _Closure>
+ // expected-error@+1{{class member cannot be redeclared}}
+ void foo2(_View &&, _Closure &&)
+ requires same_as<_Tp, _View>
+ {}
+
+ template <same_as<_Tp> _View, typename _Closure>
+ // expected-note@+1{{previous definition is here}}
+ void foo3(_View &&, _Closure &&) {}
+ template <same_as<_Tp> _View, typename _Closure>
+ // expected-error@+1{{class member cannot be redeclared}}
+ void foo3(_View &&, _Closure &&) {}
+};
+
+// Requires instantiation to fail, so no errors here.
+template <class _Tp> struct __range_adaptor_closure5 {
+ template <same_as<_Tp> U>
+ friend void foo() {}
+ template <same_as<_Tp> U>
+ friend void foo() {}
+};
+
+template <class _Tp> struct __range_adaptor_closure6 {
+ template <same_as<_Tp> U>
+ friend void foo() {} // #RAC6FOO1
+ template <same_as<_Tp> U>
+ friend void foo() {} // #RAC6FOO2
+};
+struct A6 : __range_adaptor_closure6<A6> {};
+// expected-error@#RAC6FOO2{{redefinition of 'foo'}}
+// expected-note@-2{{in instantiation of template class}}
+// expected-note@#RAC6FOO1{{previous definition is here}}
+
+template <class T> struct S1 {
+ template <typename U>
+ friend void dupe() {} // #S1DUPE
+
+ template <typename U>
+ requires same_as<U, U>
+ friend void dupe2() {} // #S1DUPE2
+};
+template <class T> struct S2 {
+ template <typename U>
+ friend void dupe() {} // #S2DUPE
+
+ template <typename U>
+ requires same_as<U, U>
+ friend void dupe2() {} // #S2DUPE2
+};
+
+template <class T> struct S3 {
+ template <typename U>
+ requires same_as<T, U>
+ friend void dupe() {}
+};
+template <class T> struct S4 {
+ template <typename U>
+ requires same_as<T, U>
+ friend void dupe() {}
+};
+
+// Same as S3 and S4, but aren't instantiated with the same T.
+template <class T> struct S5 {
+ template <typename U>
+ requires same_as<T, U>
+ friend void not_dupe() {}
+};
+template <class T> struct S6 {
+ template <typename U>
+ requires same_as<T, U>
+ friend void not_dupe() {}
+};
+
+template <class T> struct S7 {
+ void not_dupe()
+ requires same_as<T, T>
+ {}
+};
+
+void useS() {
+ S1<int> s1;
+ S2<double> s2;
+ // expected-error@#S2DUPE{{redefinition}}
+ // expected-note@-2{{in instantiation of template class}}
+ // expected-note@#S1DUPE{{previous definition is here}}
+ // expected-error@#S2DUPE2{{redefinition}}
+ // expected-note@#S1DUPE2{{previous definition is here}}
+
+ // OK, they have different 'scopes'.
+ S3<int> s3;
+ S4<int> s4;
+
+ // OK, because only instantiated with different T.
+ S5<int> s5;
+ S6<double> s6;
+
+ S7<int> s7;
+}
+
+} // namespace LibCXXOperatorRedef
C auto **&j2 = g(); // expected-error {{deduced type 'int' does not satisfy 'C'}}
C auto **&&j3 = g(); // expected-error {{deduced type 'int' does not satisfy 'C'}}
}
+
+namespace SubConstraintChecks {
+template <typename T>
+concept TrueConstraint = true;
+template <typename T>
+concept FalseConstraint = false;
+
+template <typename T, typename... Us>
+class ContainsConstrainedFuncTrue {
+public:
+ template <typename V, TrueConstraint Constrained>
+ static void func(V &&, Constrained &&C);
+};
+template <typename T, typename... Us>
+class ContainsConstrainedFuncFalse {
+public:
+ template <typename V, FalseConstraint Constrained>
+ static void func(V &&, Constrained &&C);
+};
+
+template <typename... Us>
+concept TrueConstraint2 =
+ requires(float &&t) {
+ ContainsConstrainedFuncTrue<float, Us...>::func(5, 0.0);
+ };
+template <typename... Us>
+concept FalseConstraint2 =
+ requires(float &&t) {
+ ContainsConstrainedFuncFalse<float, Us...>::func(5, 0.0); // #FC2_CONSTR
+ };
+
+template <typename T>
+void useTrue(int F)
+ requires TrueConstraint2<int>
+{}
+
+template <typename T>
+void useFalse(int F) // #USE_FALSE
+ requires FalseConstraint2<int> // #USE_FALSE_CONSTR
+{}
+
+// Should only diagnose 'false' once instantiated.
+void UseUse() {
+ useTrue<int>(5);
+ useFalse<int>(5);
+ // expected-error@-1{{no matching function for call to 'useFalse'}}
+ // expected-note@#USE_FALSE{{constraints not satisfied}}
+ // expected-note@#USE_FALSE_CONSTR{{because 'int' does not satisfy 'FalseConstraint2'}}
+ // expected-note@#FC2_CONSTR {{would be invalid: no matching function for call to 'func'}}
+}
+} // namespace SubConstraintChecks
+
+namespace DeducedTemplateArgs {
+template <typename Itr> struct ItrTraits {
+ template <typename PtrItr> struct Ptr {
+ };
+ template <typename PtrItr>
+ requires requires { typename PtrItr::pointer; }
+ struct Ptr<PtrItr> {
+ using type = typename Itr::pointer;
+ };
+ using pointer = typename Ptr<Itr>::type; // #TRAITS_PTR
+};
+
+struct complete_itr {
+ using pointer = int;
+};
+
+template <typename T> class Complete {
+ using ItrType = ItrTraits<complete_itr>;
+ ItrType begin() noexcept { return ItrType(); }
+};
+
+// This version doesn't have 'pointer', so error confirms we are in the first
+// verison of 'Ptr'.
+struct not_complete_itr {
+};
+
+template <typename T> class NotComplete {
+ using ItrType = ItrTraits<not_complete_itr>;
+ ItrType begin() noexcept { return ItrType(); }
+ // expected-error@#TRAITS_PTR{{no type named 'type' in }}
+ // expected-note@-2{{in instantiation of template class }}
+};
+} // namespace DeducedTemplateArgs
+
+namespace DeferredInstantiationInstScope {
+template <typename T>
+struct remove_ref {
+ using type = T;
+};
+template <typename T>
+struct remove_ref<T &> {
+ using type = T;
+};
+template <typename T>
+struct remove_ref<T &&> {
+ using type = T;
+};
+
+template <typename T>
+constexpr bool IsInt = PR54443::is_same<typename remove_ref<T>::type,
+ int>::value;
+
+template <typename U>
+void SingleDepthReferencesTop(U &&u) {
+ struct lc {
+ void operator()() // #SDRT_OP
+ requires IsInt<decltype(u)> // #SDRT_REQ
+ {}
+ };
+ lc lv;
+ lv(); // #SDRT_CALL
+}
+
+template <typename U>
+void SingleDepthReferencesTopNotCalled(U &&u) {
+ struct lc {
+ void operator()()
+ requires IsInt<typename decltype(u)::FOO>
+ {}
+ };
+ lc lv;
+}
+
+template <typename U>
+void SingleDepthReferencesTopCalled(U &&u) {
+ struct lc {
+ void operator()() // #CALLOP
+ requires IsInt<typename decltype(u)::FOO> // #CONSTR
+ {}
+ };
+ lc lv;
+ lv();
+ // expected-error@-1{{no matching function for call to object of type 'lc'}}
+ // expected-note@#SDRTC{{in instantiation of function template}}
+ // expected-note@#CALLOP{{constraints not satisfied}}
+ // expected-note@#CONSTR{{substituted constraint expression is ill-formed}}
+}
+
+template <typename U>
+void SingleDepthReferencesTopLambda(U &&u) {
+ []()
+ requires IsInt<decltype(u)>
+ {}();
+}
+
+template <typename U>
+void DoubleDepthReferencesTop(U &&u) {
+ struct lc { // #DDRT_STRCT
+ void operator()() {
+ struct lc2 {
+ void operator()() // #DDRT_OP
+ requires IsInt<decltype(u)> // #DDRT_REQ
+ {}
+ };
+ lc2 lv2;
+ lv2(); // #DDRT_CALL
+ }
+ };
+ lc lv;
+ lv();
+}
+
+template <typename U>
+void DoubleDepthReferencesTopLambda(U &&u) {
+ []() { []()
+ requires IsInt<decltype(u)>
+ {}(); }();
+}
+
+template <typename U>
+void DoubleDepthReferencesAll(U &&u) {
+ struct lc { // #DDRA_STRCT
+ void operator()(U &&u2) {
+ struct lc2 {
+ void operator()(U &&u3) // #DDRA_OP
+ requires IsInt<decltype(u)> && // #DDRA_REQ
+ IsInt<decltype(u2)> && IsInt<decltype(u3)>
+ {}
+ };
+ lc2 lv2;
+ lv2(u2); // #DDRA_CALL
+ }
+ };
+ lc lv;
+ lv(u);
+}
+
+template <typename U>
+void DoubleDepthReferencesAllLambda(U &&u) {
+ [](U &&u2) {
+ [](U && u3)
+ requires IsInt<decltype(u)> &&
+ IsInt<decltype(u2)> && IsInt<decltype(u3)>
+ {}(u2);
+ }(u);
+}
+
+template <typename U>
+struct CausesFriendConstraint {
+ template <typename V>
+ friend void FriendFunc(CausesFriendConstraint, V) // #FF_DECL
+ requires IsInt<U> &&
+ IsInt<V> // #FF_REQ
+ {}
+};
+// FIXME: Re-enable this test when constraints are allowed to refer to captures.
+// template<typename T>
+// void ChecksCapture(T x) {
+// [y = x]() requires(IsInt<decltype(y)>){}();
+// }
+
+template <typename T>
+void ChecksLocalVar(T x) {
+ T Local;
+ []()
+ requires(IsInt<decltype(Local)>)
+ {}();
+}
+
+template <typename T>
+void LocalStructMemberVar(T x) {
+ struct S {
+ T local;
+ void foo()
+ requires(IsInt<decltype(local)>) // #LSMV_REQ
+ {}
+ } s;
+ s.foo(); // #LSMV_CALL
+};
+
+template <typename T>
+struct ChecksMemberVar {
+ T t;
+ void foo()
+ requires(IsInt<decltype(t)>) // #CMV_FOO
+ {}
+ template <typename U>
+ void foo2() // #CMV_FOO2
+ requires(IsInt<decltype(t)>) // #CMV_FOO2_REQ
+ {}
+};
+
+void test_dependent() {
+ int v = 0;
+ float will_fail;
+ SingleDepthReferencesTop(v);
+ SingleDepthReferencesTop(will_fail);
+ // expected-error@#SDRT_CALL{{no matching function for call to object of type 'lc'}}
+ // expected-note@-2{{in instantiation of function template specialization}}
+ // expected-note@#SDRT_OP{{candidate function not viable}}
+ // expected-note@#SDRT_REQ{{'IsInt<decltype(u)>' evaluated to false}}
+
+ SingleDepthReferencesTopNotCalled(v);
+ // Won't error unless we try to call it.
+ SingleDepthReferencesTopNotCalled(will_fail);
+ SingleDepthReferencesTopCalled(v); // #SDRTC
+ SingleDepthReferencesTopLambda(v);
+ // FIXME: This should error on constraint failure! (Lambda!)
+ SingleDepthReferencesTopLambda(will_fail);
+ DoubleDepthReferencesTop(v);
+ DoubleDepthReferencesTop(will_fail);
+ // expected-error@#DDRT_CALL{{no matching function for call to object of type 'lc2'}}
+ // expected-note@-2{{in instantiation of function template specialization}}
+ // expected-note@#DDRT_STRCT{{in instantiation of member function}}
+ // expected-note@#DDRT_OP{{candidate function not viable}}
+ // expected-note@#DDRT_REQ{{'IsInt<decltype(u)>' evaluated to false}}
+
+ DoubleDepthReferencesTopLambda(v);
+ // FIXME: This should error on constraint failure! (Lambda!)
+ DoubleDepthReferencesTopLambda(will_fail);
+ DoubleDepthReferencesAll(v);
+ DoubleDepthReferencesAll(will_fail);
+ // expected-error@#DDRA_CALL{{no matching function for call to object of type 'lc2'}}
+ // expected-note@-2{{in instantiation of function template specialization}}
+ // expected-note@#DDRA_STRCT{{in instantiation of member function}}
+ // expected-note@#DDRA_OP{{candidate function not viable}}
+ // expected-note@#DDRA_REQ{{'IsInt<decltype(u)>' evaluated to false}}
+
+ DoubleDepthReferencesAllLambda(v);
+ // FIXME: This should error on constraint failure! (Lambda!)
+ DoubleDepthReferencesAllLambda(will_fail);
+
+ CausesFriendConstraint<int> CFC;
+ FriendFunc(CFC, 1);
+ FriendFunc(CFC, 1.0);
+ // expected-error@-1{{no matching function for call to 'FriendFunc'}}
+ // expected-note@#FF_DECL{{constraints not satisfied}}
+ // expected-note@#FF_REQ{{because 'IsInt<double>' evaluated to false}}
+
+ // FIXME: Re-enable this test when constraints are allowed to refer to captures.
+ // ChecksCapture(v);
+
+ ChecksLocalVar(v);
+ // FIXME: This should error on constraint failure! (Lambda!)
+ ChecksLocalVar(will_fail);
+
+ LocalStructMemberVar(v);
+ LocalStructMemberVar(will_fail);
+ // expected-error@#LSMV_CALL{{invalid reference to function 'foo'}}
+ // expected-note@-2{{in instantiation of function template specialization}}
+ // expected-note@#LSMV_REQ{{because 'IsInt<decltype(this->local)>' evaluated to false}}
+
+ ChecksMemberVar<int> CMV;
+ CMV.foo();
+ CMV.foo2<int>();
+
+ ChecksMemberVar<float> CMV2;
+ CMV2.foo();
+ // expected-error@-1{{invalid reference to function 'foo'}}
+ // expected-note@#CMV_FOO{{because 'IsInt<decltype(this->t)>' evaluated to false}}
+ CMV2.foo2<float>();
+ // expected-error@-1{{no matching member function for call to 'foo2'}}
+ // expected-note@#CMV_FOO2{{constraints not satisfied}}
+ // expected-note@#CMV_FOO2_REQ{{because 'IsInt<decltype(this->t)>' evaluated to false}}
+}
+} // namespace DeferredInstantiationInstScope
+
+// Ane example of evaluating a concept at two different depths in the same
+// evaluation. No diagnostic is expected.
+namespace SameConceptDifferentDepth {
+template <class _Ip>
+concept sentinel_for =
+ requires(_Ip __i) {
+ __i++;
+ };
+
+template <class _Ip>
+concept bidirectional_iterator =
+ sentinel_for<_Ip>;
+
+template <class _Iter>
+class move_iterator {
+public:
+ auto operator++(int)
+ requires sentinel_for<_Iter>{}
+};
+
+static_assert(bidirectional_iterator<move_iterator<int>>);
+} // namespace SameConceptDifferentDepth
+
+namespace VarInit {
+template <class _Tp>
+concept __can_reference = true;
+
+template <class _Iter>
+class common_iterator {
+public:
+ common_iterator() {
+ constexpr auto x = requires(_Iter & __i) { { __i } -> __can_reference; };
+ }
+};
+
+void test() {
+ auto commonIter1 = common_iterator<int>();
+}
+} // namespace VarInit
+
+
+namespace InlineFriendOperator {
+template <typename T>
+concept C = true;
+template <class _Iter>
+class counted_iterator {
+ _Iter I;
+public:
+ constexpr counted_iterator() = default;
+ friend constexpr auto operator+( // expected-note {{candidate function not viable}}
+ int __n, const counted_iterator &__x)
+ requires C<decltype(I)>
+ {
+ return __x + __n; // expected-error{{invalid operands to binary expression}}
+ }
+};
+
+constexpr bool test() {
+ counted_iterator<int> iter;
+ auto x = 2 + iter; // expected-note{{in instantiation of member function 'InlineFriendOperator::operator+'}}
+
+ return true;
+}
+} // namespace InlineFriendOperator
+
--- /dev/null
+// RUN: %clang_cc1 -std=c++2a -x c++ %s -verify -fsyntax-only -Wno-unused-value
+// expected-no-diagnostics
+
+namespace GithubBug44178 {
+template <typename D>
+struct CRTP {
+ void call_foo()
+ requires requires(D &v) { v.foo(); }
+ {
+ static_cast<D *>(this)->foo();
+ }
+};
+
+struct Test : public CRTP<Test> {
+ void foo() {}
+};
+
+int main() {
+ Test t;
+ t.call_foo();
+ return 0;
+}
+} // namespace GithubBug44178
-// RUN: %clang_cc1 -std=c++2a -x c++ %s -verify
+// RUN: %clang_cc1 -std=c++2a -x c++ %s -Wno-unused-value -verify
template <typename... Args> requires ((sizeof(Args) == 1), ...)
// expected-note@-1 {{because '(sizeof(int) == 1) , (sizeof(char) == 1) , (sizeof(int) == 1)' evaluated to false}}
static_assert(S<void>::f(1));
+// Similar to the 'S' test, but tries to use 'U' in the requires clause.
+template <typename T2>
+struct S1 {
+ // expected-note@+3 {{candidate template ignored: constraints not satisfied [with U = int]}}
+ // expected-note@+3 {{because substituted constraint expression is ill-formed: type 'int' cannot be used prior to '::' because it has no members}}
+ template <typename U>
+ static constexpr auto f(U const index)
+ requires(U::foo)
+ { return true; }
+};
+
+// expected-error@+1 {{no matching function for call to 'f'}}
+static_assert(S1<void>::f(1));
+
constexpr auto value = 0;
template<typename T>
--- /dev/null
+// RUN: %clang_cc1 -std=c++20 -verify %s
+
+template <class T>
+ requires(sizeof(T) > 2) || T::value // #FOO_REQ
+void Foo(T){}; // #FOO
+
+template <class T>
+void TrailingReturn(T) // #TRAILING
+ requires(sizeof(T) > 2) || // #TRAILING_REQ
+ T::value // #TRAILING_REQ_VAL
+{};
+template <bool B>
+struct HasValue {
+ static constexpr bool value = B;
+};
+static_assert(sizeof(HasValue<true>) <= 2);
+
+template <bool B>
+struct HasValueLarge {
+ static constexpr bool value = B;
+ int I;
+};
+static_assert(sizeof(HasValueLarge<true>) > 2);
+
+void usage() {
+ // Passes the 1st check, short-circuit so the 2nd ::value is not evaluated.
+ Foo(1.0);
+ TrailingReturn(1.0);
+
+ // Fails the 1st check, but has a ::value, so the check happens correctly.
+ Foo(HasValue<true>{});
+ TrailingReturn(HasValue<true>{});
+
+ // Passes the 1st check, but would have passed the 2nd one.
+ Foo(HasValueLarge<true>{});
+ TrailingReturn(HasValueLarge<true>{});
+
+ // Fails the 1st check, fails 2nd because there is no ::value.
+ Foo(true);
+ // expected-error@-1{{no matching function for call to 'Foo'}}
+ // expected-note@#FOO{{candidate template ignored: constraints not satisfied [with T = bool]}}
+ // expected-note@#FOO_REQ{{because 'sizeof(_Bool) > 2' (1 > 2) evaluated to false}}
+ // expected-note@#FOO_REQ{{because substituted constraint expression is ill-formed: type 'bool' cannot be used prior to '::' because it has no members}}
+
+ TrailingReturn(true);
+ // expected-error@-1{{no matching function for call to 'TrailingReturn'}}
+ // expected-note@#TRAILING{{candidate template ignored: constraints not satisfied [with T = bool]}}
+ // expected-note@#TRAILING_REQ{{because 'sizeof(_Bool) > 2' (1 > 2) evaluated to false}}
+ // expected-note@#TRAILING_REQ_VAL{{because substituted constraint expression is ill-formed: type 'bool' cannot be used prior to '::' because it has no members}}
+
+ // Fails the 1st check, fails 2nd because ::value is false.
+ Foo(HasValue<false>{});
+ // expected-error@-1 {{no matching function for call to 'Foo'}}
+ // expected-note@#FOO{{candidate template ignored: constraints not satisfied [with T = HasValue<false>]}}
+ // expected-note@#FOO_REQ{{because 'sizeof(HasValue<false>) > 2' (1 > 2) evaluated to false}}
+ // expected-note@#FOO_REQ{{and 'HasValue<false>::value' evaluated to false}}
+ TrailingReturn(HasValue<false>{});
+ // expected-error@-1 {{no matching function for call to 'TrailingReturn'}}
+ // expected-note@#TRAILING{{candidate template ignored: constraints not satisfied [with T = HasValue<false>]}}
+ // expected-note@#TRAILING_REQ{{because 'sizeof(HasValue<false>) > 2' (1 > 2) evaluated to false}}
+ // expected-note@#TRAILING_REQ_VAL{{and 'HasValue<false>::value' evaluated to false}}
+}