erichkeane updated this revision to Diff 421186.
erichkeane marked 2 inline comments as done.
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Make suggestions from @ChuanqiXu
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https://reviews.llvm.org/D119544/new/
https://reviews.llvm.org/D119544
Files:
clang/docs/ReleaseNotes.rst
clang/include/clang/Sema/Sema.h
clang/include/clang/Sema/Template.h
clang/lib/Sema/SemaConcept.cpp
clang/lib/Sema/SemaTemplate.cpp
clang/lib/Sema/SemaTemplateDeduction.cpp
clang/lib/Sema/SemaTemplateInstantiate.cpp
clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
clang/lib/Sema/TreeTransform.h
clang/test/CXX/temp/temp.constr/temp.constr.constr/non-function-templates.cpp
clang/test/SemaTemplate/deferred-concept-inst.cpp
clang/test/SemaTemplate/instantiate-requires-clause.cpp
clang/test/SemaTemplate/trailing-return-short-circuit.cpp
Index: clang/test/SemaTemplate/trailing-return-short-circuit.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaTemplate/trailing-return-short-circuit.cpp
@@ -0,0 +1,61 @@
+// 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}}
+}
Index: clang/test/SemaTemplate/instantiate-requires-clause.cpp
===================================================================
--- clang/test/SemaTemplate/instantiate-requires-clause.cpp
+++ clang/test/SemaTemplate/instantiate-requires-clause.cpp
@@ -40,6 +40,18 @@
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@+2 {{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>
Index: clang/test/SemaTemplate/deferred-concept-inst.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaTemplate/deferred-concept-inst.cpp
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -std=c++2a -x c++ %s -verify -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
Index: clang/test/CXX/temp/temp.constr/temp.constr.constr/non-function-templates.cpp
===================================================================
--- clang/test/CXX/temp/temp.constr/temp.constr.constr/non-function-templates.cpp
+++ clang/test/CXX/temp/temp.constr/temp.constr.constr/non-function-templates.cpp
@@ -90,3 +90,24 @@
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
Index: clang/lib/Sema/TreeTransform.h
===================================================================
--- clang/lib/Sema/TreeTransform.h
+++ clang/lib/Sema/TreeTransform.h
@@ -12974,11 +12974,8 @@
}
// 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);
+ ExprResult NewTrailingRequiresClause =
+ E->getCallOperator()->getTrailingRequiresClause();
// Create the local class that will describe the lambda.
Index: clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
===================================================================
--- clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2037,19 +2037,7 @@
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
@@ -2394,22 +2382,7 @@
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) {
@@ -2741,9 +2714,6 @@
// 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))
return nullptr;
}
@@ -3986,18 +3956,7 @@
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(),
Index: clang/lib/Sema/SemaTemplateInstantiate.cpp
===================================================================
--- clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -55,9 +55,18 @@
/// 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;
@@ -153,11 +162,13 @@
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?");
}
@@ -174,10 +185,18 @@
}
} 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());
+ }
}
}
@@ -2304,6 +2323,17 @@
const MultiLevelTemplateArgumentList &TemplateArgs) {
const ASTTemplateArgumentListInfo *TemplArgInfo =
TC->getTemplateArgsAsWritten();
+
+ // If we're not checking a constraint, we shouldn't be instantiating the type
+ // constraint, so we should just create a copy of the previous one.
+ if (!IsEvaluatingAConstraint()) {
+ Inst->setTypeConstraint(TC->getNestedNameSpecifierLoc(),
+ TC->getConceptNameInfo(), TC->getNamedConcept(),
+ TC->getNamedConcept(), TemplArgInfo,
+ TC->getImmediatelyDeclaredConstraint());
+ return false;
+ }
+
TemplateArgumentListInfo InstArgs;
if (TemplArgInfo) {
@@ -3488,6 +3518,14 @@
return Instantiator.TransformExpr(E);
}
+ExprResult
+Sema::SubstConstraintExpr(Expr *E,
+ const MultiLevelTemplateArgumentList &TemplateArgs) {
+
+ ConstraintEvalRAII EvalRAII(*this);
+ return SubstExpr(E, TemplateArgs);
+}
+
ExprResult Sema::SubstInitializer(Expr *Init,
const MultiLevelTemplateArgumentList &TemplateArgs,
bool CXXDirectInit) {
Index: clang/lib/Sema/SemaTemplateDeduction.cpp
===================================================================
--- clang/lib/Sema/SemaTemplateDeduction.cpp
+++ clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -2791,8 +2791,10 @@
TemplateDeductionInfo& Info) {
llvm::SmallVector<const Expr *, 3> AssociatedConstraints;
Template->getAssociatedConstraints(AssociatedConstraints);
- if (S.CheckConstraintSatisfaction(Template, AssociatedConstraints,
- DeducedArgs, Info.getLocation(),
+ MultiLevelTemplateArgumentList MLTAL;
+ MLTAL.addOuterTemplateArguments(DeducedArgs);
+ if (S.CheckConstraintSatisfaction(Template, AssociatedConstraints, MLTAL,
+ Info.getLocation(),
Info.AssociatedConstraintsSatisfaction) ||
!Info.AssociatedConstraintsSatisfaction.IsSatisfied) {
Info.reset(TemplateArgumentList::CreateCopy(S.Context, DeducedArgs));
@@ -4572,8 +4574,11 @@
if (S.CheckTemplateArgumentList(Concept, SourceLocation(), TemplateArgs,
/*PartialTemplateArgs=*/false, Converted))
return Sema::DAR_FailedAlreadyDiagnosed;
+
+ MultiLevelTemplateArgumentList MLTAL;
+ MLTAL.addOuterTemplateArguments(Converted);
if (S.CheckConstraintSatisfaction(Concept, {Concept->getConstraintExpr()},
- Converted, TypeLoc.getLocalSourceRange(),
+ MLTAL, TypeLoc.getLocalSourceRange(),
Satisfaction))
return Sema::DAR_FailedAlreadyDiagnosed;
if (!Satisfaction.IsSatisfied) {
Index: clang/lib/Sema/SemaTemplate.cpp
===================================================================
--- clang/lib/Sema/SemaTemplate.cpp
+++ clang/lib/Sema/SemaTemplate.cpp
@@ -4698,9 +4698,11 @@
bool AreArgsDependent =
TemplateSpecializationType::anyDependentTemplateArguments(*TemplateArgs,
Converted);
+ MultiLevelTemplateArgumentList MLTAL;
+ MLTAL.addOuterTemplateArguments(Converted);
if (!AreArgsDependent &&
CheckConstraintSatisfaction(
- NamedConcept, {NamedConcept->getConstraintExpr()}, Converted,
+ NamedConcept, {NamedConcept->getConstraintExpr()}, MLTAL,
SourceRange(SS.isSet() ? SS.getBeginLoc() : ConceptNameInfo.getLoc(),
TemplateArgs->getRAngleLoc()),
Satisfaction))
@@ -5560,6 +5562,7 @@
if (Inst.isInvalid())
return true;
+ ConstraintEvalRAII EvalRAII(*this);
TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
Params = SubstTemplateParams(Params, CurContext,
MultiLevelTemplateArgumentList(TemplateArgs));
@@ -5917,13 +5920,20 @@
if (UpdateArgsWithConversions)
TemplateArgs = std::move(NewArgs);
- if (!PartialTemplateArgs &&
- EnsureTemplateArgumentListConstraints(
- Template, Converted, SourceRange(TemplateLoc,
- TemplateArgs.getRAngleLoc()))) {
- if (ConstraintsNotSatisfied)
- *ConstraintsNotSatisfied = true;
- return true;
+ if (!PartialTemplateArgs) {
+ 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()))) {
+ if (ConstraintsNotSatisfied)
+ *ConstraintsNotSatisfied = true;
+ return true;
+ }
}
return false;
@@ -7453,7 +7463,9 @@
// are not considered.
if (ParamsAC.empty())
return false;
+
Template->getAssociatedConstraints(TemplateAC);
+
bool IsParamAtLeastAsConstrained;
if (IsAtLeastAsConstrained(Param, ParamsAC, Template, TemplateAC,
IsParamAtLeastAsConstrained))
Index: clang/lib/Sema/SemaConcept.cpp
===================================================================
--- clang/lib/Sema/SemaConcept.cpp
+++ clang/lib/Sema/SemaConcept.cpp
@@ -30,6 +30,7 @@
namespace {
class LogicalBinOp {
+ SourceLocation Loc;
OverloadedOperatorKind Op = OO_None;
const Expr *LHS = nullptr;
const Expr *RHS = nullptr;
@@ -40,12 +41,14 @@
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();
}
}
}
@@ -56,6 +59,22 @@
const Expr *getLHS() const { return LHS; }
const Expr *getRHS() const { return RHS; }
+
+ ExprResult recreateBinOp(Sema &SemaRef, ExprResult LHS) {
+ return recreateBinOp(SemaRef, LHS, const_cast<Expr *>(getRHS()));
+ }
+
+ ExprResult recreateBinOp(Sema &SemaRef, ExprResult LHS, ExprResult RHS) {
+ assert((isAnd() || isOr()) && "Not the right kind of op?");
+ assert((!LHS.isInvalid() && !RHS.isInvalid()) && "not good expressions?");
+ assert(LHS.isUsable() && RHS.isUsable() && "Side not usable?");
+ // 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{});
+ }
};
}
@@ -122,16 +141,18 @@
}
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;
@@ -142,7 +163,7 @@
// 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 LHSRes.isUsable() ? BO.recreateBinOp(S, LHSRes) : ExprEmpty();
if (BO.isAnd() && !IsLHSSatisfied)
// [temp.constr.op] p2
@@ -151,12 +172,21 @@
// 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 LHSRes.isUsable() ? BO.recreateBinOp(S, LHSRes) : ExprEmpty();
- return calculateConstraintSatisfaction(
+ ExprResult RHSRes = calculateConstraintSatisfaction(
S, BO.getRHS(), Satisfaction, std::forward<AtomicEvaluator>(Evaluator));
+ if (RHSRes.isInvalid())
+ return ExprError();
+
+ if (!LHSRes.isUsable() || !RHSRes.isUsable())
+ return ExprEmpty();
+ return BO.recreateBinOp(S, LHSRes, RHSRes);
} else if (auto *C = dyn_cast<ExprWithCleanups>(ConstraintExpr)) {
- return calculateConstraintSatisfaction(S, C->getSubExpr(), Satisfaction,
+ // 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));
}
@@ -164,11 +194,11 @@
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);
@@ -185,7 +215,7 @@
<< SubstitutedAtomicExpr.get()->getSourceRange();
for (const PartialDiagnosticAt &PDiag : EvaluationDiags)
S.Diag(PDiag.first, PDiag.second);
- return true;
+ return ExprError();
}
assert(EvalResult.Val.isInt() &&
@@ -195,13 +225,13 @@
Satisfaction.Details.emplace_back(ConstraintExpr,
SubstitutedAtomicExpr.get());
- return false;
+ return SubstitutedAtomicExpr;
}
-static bool calculateConstraintSatisfaction(
- Sema &S, const NamedDecl *Template, ArrayRef<TemplateArgument> TemplateArgs,
- SourceLocation TemplateNameLoc, MultiLevelTemplateArgumentList &MLTAL,
- const Expr *ConstraintExpr, ConstraintSatisfaction &Satisfaction) {
+static ExprResult calculateConstraintSatisfaction(
+ Sema &S, const NamedDecl *Template, SourceLocation TemplateNameLoc,
+ const MultiLevelTemplateArgumentList &MLTAL, const Expr *ConstraintExpr,
+ ConstraintSatisfaction &Satisfaction) {
return calculateConstraintSatisfaction(
S, ConstraintExpr, Satisfaction, [&](const Expr *AtomicExpr) {
EnterExpressionEvaluationContext ConstantEvaluated(
@@ -219,8 +249,8 @@
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
@@ -268,56 +298,70 @@
});
}
-static bool CheckConstraintSatisfaction(Sema &S, const NamedDecl *Template,
- ArrayRef<const Expr *> ConstraintExprs,
- ArrayRef<TemplateArgument> TemplateArgs,
- SourceRange TemplateIDRange,
- ConstraintSatisfaction &Satisfaction) {
+static bool CheckConstraintSatisfaction(
+ Sema &S, const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
+ llvm::SmallVectorImpl<Expr *> &Converted,
+ const MultiLevelTemplateArgumentList &TemplateArgsList,
+ SourceRange TemplateIDRange, ConstraintSatisfaction &Satisfaction) {
if (ConstraintExprs.empty()) {
Satisfaction.IsSatisfied = true;
return false;
}
- for (auto& Arg : TemplateArgs)
- if (Arg.isInstantiationDependent()) {
- // No need to check satisfaction for dependent constraint expressions.
- Satisfaction.IsSatisfied = true;
- return false;
- }
+ if (TemplateArgsList.isAnyArgInstantiationDependent()) {
+ // No need to check satisfaction for dependent constraint expressions.
+ Satisfaction.IsSatisfied = true;
+ return false;
+ }
+
+ ArrayRef<TemplateArgument> TemplateArgs =
+ TemplateArgsList.getNumSubstitutedLevels() > 0
+ ? TemplateArgsList.getOutermost()
+ : ArrayRef<TemplateArgument>{};
- Sema::InstantiatingTemplate Inst(S, TemplateIDRange.getBegin(),
+ Sema::InstantiatingTemplate Inst(
+ S, TemplateIDRange.getBegin(),
Sema::InstantiatingTemplate::ConstraintsCheck{},
const_cast<NamedDecl *>(Template), TemplateArgs, TemplateIDRange);
if (Inst.isInvalid())
return true;
- MultiLevelTemplateArgumentList MLTAL;
- MLTAL.addOuterTemplateArguments(TemplateArgs);
-
for (const Expr *ConstraintExpr : ConstraintExprs) {
- if (calculateConstraintSatisfaction(S, Template, TemplateArgs,
- TemplateIDRange.getBegin(), MLTAL,
- ConstraintExpr, Satisfaction))
+ ExprResult Res = calculateConstraintSatisfaction(
+ S, Template, TemplateIDRange.getBegin(), TemplateArgsList,
+ ConstraintExpr, Satisfaction);
+ if (Res.isInvalid())
return true;
- if (!Satisfaction.IsSatisfied)
- // [temp.constr.op] p2
+
+ Converted.push_back(Res.get());
+ if (!Satisfaction.IsSatisfied) {
+ // Backfill the 'converted' list with nulls so we can keep the Converted
+ Converted.append(ConstraintExprs.size() - Converted.size(), nullptr);
+ // and unconverted lists in sync. [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. [...]
return false;
+ }
}
return false;
}
bool Sema::CheckConstraintSatisfaction(
const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
- ArrayRef<TemplateArgument> TemplateArgs, SourceRange TemplateIDRange,
- ConstraintSatisfaction &OutSatisfaction) {
+ llvm::SmallVectorImpl<Expr *> &ConvertedConstraints,
+ const MultiLevelTemplateArgumentList &TemplateArgsList,
+ SourceRange TemplateIDRange, ConstraintSatisfaction &OutSatisfaction) {
if (ConstraintExprs.empty()) {
OutSatisfaction.IsSatisfied = true;
return false;
}
+ ArrayRef<TemplateArgument> TemplateArgs =
+ TemplateArgsList.getNumSubstitutedLevels() > 0
+ ? TemplateArgsList.getOutermost()
+ : ArrayRef<TemplateArgument>{};
+
llvm::FoldingSetNodeID ID;
void *InsertPos;
ConstraintSatisfaction *Satisfaction = nullptr;
@@ -334,8 +378,8 @@
Satisfaction = &OutSatisfaction;
}
if (::CheckConstraintSatisfaction(*this, Template, ConstraintExprs,
- TemplateArgs, TemplateIDRange,
- *Satisfaction)) {
+ ConvertedConstraints, TemplateArgsList,
+ TemplateIDRange, *Satisfaction)) {
if (ShouldCache)
delete Satisfaction;
return true;
@@ -353,20 +397,83 @@
bool Sema::CheckConstraintSatisfaction(const Expr *ConstraintExpr,
ConstraintSatisfaction &Satisfaction) {
return calculateConstraintSatisfaction(
- *this, ConstraintExpr, Satisfaction,
- [](const Expr *AtomicExpr) -> ExprResult {
- return ExprResult(const_cast<Expr *>(AtomicExpr));
- });
+ *this, ConstraintExpr, Satisfaction,
+ [](const Expr *AtomicExpr) -> ExprResult {
+ return ExprResult(const_cast<Expr *>(AtomicExpr));
+ })
+ .isInvalid();
+}
+
+// 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 (FD->isTemplateInstantiation() && FD->getPrimaryTemplate()) {
+ FunctionTemplateDecl *PrimaryTemplate = FD->getPrimaryTemplate();
+ InstantiatingTemplate Inst(
+ *this, FD->getPointOfInstantiation(),
+ InstantiatingTemplate::ConstraintsCheck{}, PrimaryTemplate,
+ TemplateArgs ? *TemplateArgs : ArrayRef<TemplateArgument>{},
+ SourceRange());
+ if (Inst.isInvalid())
+ return {};
+
+ // 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 (TemplateArgs) {
+ MultiLevelTemplateArgumentList JustTemplArgs(
+ *FD->getTemplateSpecializationArgs());
+ if (addInstantiatedParametersToScope(
+ FD, PrimaryTemplate->getTemplatedDecl(), Scope, JustTemplArgs))
+ return {};
+ }
+
+ // 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 {};
+ }
+ }
+
+ return MLTAL;
}
bool Sema::CheckFunctionConstraints(const FunctionDecl *FD,
ConstraintSatisfaction &Satisfaction,
SourceLocation UsageLoc) {
- const Expr *RC = FD->getTrailingRequiresClause();
- if (RC->isInstantiationDependent()) {
+ // 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;
}
+
+ LocalInstantiationScope Scope(*this);
+ llvm::Optional<MultiLevelTemplateArgumentList> MLTAL =
+ SetupConstraintCheckingTemplateArgumentsAndScope(
+ const_cast<FunctionDecl *>(FD), {}, Scope);
+
Qualifiers ThisQuals;
CXXRecordDecl *Record = nullptr;
if (auto *Method = dyn_cast<CXXMethodDecl>(FD)) {
@@ -377,14 +484,27 @@
// 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;
+
+ // Attn Reviewers: 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(
- TemplateDecl *TD, ArrayRef<TemplateArgument> TemplateArgs,
+ TemplateDecl *TD, MultiLevelTemplateArgumentList TemplateArgs,
SourceRange TemplateIDRange) {
ConstraintSatisfaction Satisfaction;
llvm::SmallVector<const Expr *, 3> AssociatedConstraints;
@@ -397,7 +517,8 @@
SmallString<128> TemplateArgString;
TemplateArgString = " ";
TemplateArgString += getTemplateArgumentBindingsText(
- TD->getTemplateParameters(), TemplateArgs.data(), TemplateArgs.size());
+ TD->getTemplateParameters(), TemplateArgs.getInnermost().data(),
+ TemplateArgs.getInnermost().size());
Diag(TemplateIDRange.getBegin(),
diag::err_template_arg_list_constraints_not_satisfied)
@@ -429,21 +550,13 @@
Sema::ContextRAII savedContext(*this, Decl);
LocalInstantiationScope Scope(*this);
- // 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)) {
@@ -451,7 +564,8 @@
Record = Method->getParent();
}
CXXThisScopeRAII ThisScope(*this, Record, ThisQuals, Record != nullptr);
- return CheckConstraintSatisfaction(Template, TemplateAC, TemplateArgs,
+ llvm::SmallVector<Expr *, 1> Converted;
+ return CheckConstraintSatisfaction(Template, TemplateAC, Converted, *MLTAL,
PointOfInstantiation, Satisfaction);
}
Index: clang/include/clang/Sema/Template.h
===================================================================
--- clang/include/clang/Sema/Template.h
+++ clang/include/clang/Sema/Template.h
@@ -158,6 +158,14 @@
return !(*this)(Depth, Index).isNull();
}
+ bool isAnyArgInstantiationDependent() const {
+ for (ArgList List : TemplateArgumentLists)
+ for (const TemplateArgument &TA : List)
+ if (TA.isInstantiationDependent())
+ return true;
+ return false;
+ }
+
/// Clear out a specific template argument.
void setArgument(unsigned Depth, unsigned Index,
TemplateArgument Arg) {
@@ -197,6 +205,9 @@
const ArgList &getInnermost() const {
return TemplateArgumentLists.front();
}
+
+ /// Retrieve the outermost template argument list.
+ const ArgList &getOutermost() const { return TemplateArgumentLists.back(); }
};
/// The context in which partial ordering of function templates occurs.
Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -6966,7 +6966,24 @@
LocalInstantiationScope &Scope,
const MultiLevelTemplateArgumentList &TemplateArgs);
+ llvm::Optional<MultiLevelTemplateArgumentList>
+ SetupConstraintCheckingTemplateArgumentsAndScope(
+ FunctionDecl *FD, llvm::Optional<ArrayRef<TemplateArgument>> TemplateArgs,
+ LocalInstantiationScope &Scope);
+
+ // Keep track of whether we are evaluating a constraint.
+ unsigned ConstraintEvaluationDepth = 0;
+
+ class ConstraintEvalRAII {
+ Sema &S;
+
+ public:
+ ConstraintEvalRAII(Sema &S) : S(S) { ++S.ConstraintEvaluationDepth; }
+ ~ConstraintEvalRAII() { --S.ConstraintEvaluationDepth; }
+ };
+
public:
+ bool IsEvaluatingAConstraint() { return ConstraintEvaluationDepth > 0; }
const NormalizedConstraint *
getNormalizedAssociatedConstraints(
NamedDecl *ConstrainedDecl, ArrayRef<const Expr *> AssociatedConstraints);
@@ -6996,8 +7013,10 @@
/// check (either a concept or a constrained entity).
/// \param ConstraintExprs a list of constraint expressions, treated as if
/// they were 'AND'ed together.
- /// \param TemplateArgs the list of template arguments to substitute into the
- /// constraint expression.
+ /// \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
@@ -7007,7 +7026,40 @@
/// false otherwise.
bool CheckConstraintSatisfaction(
const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
- ArrayRef<TemplateArgument> TemplateArgs,
+ const MultiLevelTemplateArgumentList &TemplateArgList,
+ SourceRange TemplateIDRange, ConstraintSatisfaction &Satisfaction) {
+ llvm::SmallVector<Expr *, 4> Converted;
+ return CheckConstraintSatisfaction(Template, ConstraintExprs, Converted,
+ TemplateArgList, 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
@@ -7043,9 +7095,9 @@
///
/// \returns true if the constrains are not satisfied or could not be checked
/// for satisfaction, false if the constraints are satisfied.
- bool EnsureTemplateArgumentListConstraints(TemplateDecl *Template,
- ArrayRef<TemplateArgument> TemplateArgs,
- SourceRange TemplateIDRange);
+ bool EnsureTemplateArgumentListConstraints(
+ TemplateDecl *Template, MultiLevelTemplateArgumentList TemplateArgs,
+ SourceRange TemplateIDRange);
/// \brief Emit diagnostics explaining why a constraint expression was deemed
/// unsatisfied.
@@ -8778,7 +8830,8 @@
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
@@ -9499,6 +9552,11 @@
ExtParameterInfoBuilder &ParamInfos);
ExprResult SubstExpr(Expr *E,
const MultiLevelTemplateArgumentList &TemplateArgs);
+ // 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.
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -195,6 +195,10 @@
`Issue 54578 <https://github.com/llvm/llvm-project/issues/54578>`_.
- Implemented `__builtin_source_location()` which enables library support for std::source_location.
+- 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>`_.
C++2b Feature Support
^^^^^^^^^^^^^^^^^^^^^
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