[Concepts] Constrained partial specializations and function overloads.
Added support for constraint satisfaction checking and partial ordering of constraints in constrained partial specialization and function template overloads.
Re-commit after fixing another crash (added regression test).
Differential Revision: https://reviews.llvm.org/D41910
diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp
old mode 100644
new mode 100755
index f917d9c..7f0bdc9
--- a/clang/lib/Sema/SemaConcept.cpp
+++ b/clang/lib/Sema/SemaConcept.cpp
@@ -17,6 +17,7 @@
#include "clang/Sema/TemplateDeduction.h"
#include "clang/Sema/Template.h"
#include "clang/AST/ExprCXX.h"
+#include "clang/AST/RecursiveASTVisitor.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/PointerUnion.h"
using namespace clang;
@@ -414,4 +415,363 @@
diagnoseUnsatisfiedConstraintExpr(*this, Pair.first, Pair.second, First);
First = false;
}
+}
+
+namespace {
+struct AtomicConstraint {
+ const Expr *ConstraintExpr;
+ llvm::Optional<llvm::SmallVector<TemplateArgumentLoc, 3>> ParameterMapping;
+
+ AtomicConstraint(Sema &S, const Expr *ConstraintExpr) :
+ ConstraintExpr(ConstraintExpr) { };
+
+ bool hasMatchingParameterMapping(ASTContext &C,
+ const AtomicConstraint &Other) const {
+ if (!ParameterMapping != !Other.ParameterMapping)
+ return false;
+ if (!ParameterMapping)
+ return true;
+ if (ParameterMapping->size() != Other.ParameterMapping->size())
+ return false;
+
+ for (unsigned I = 0, S = ParameterMapping->size(); I < S; ++I)
+ if (!C.getCanonicalTemplateArgument((*ParameterMapping)[I].getArgument())
+ .structurallyEquals(C.getCanonicalTemplateArgument(
+ (*Other.ParameterMapping)[I].getArgument())))
+ return false;
+ return true;
+ }
+
+ bool subsumes(ASTContext &C, const AtomicConstraint &Other) const {
+ // C++ [temp.constr.order] p2
+ // - an atomic constraint A subsumes another atomic constraint B
+ // if and only if the A and B are identical [...]
+ //
+ // C++ [temp.constr.atomic] p2
+ // Two atomic constraints are identical if they are formed from the
+ // same expression and the targets of the parameter mappings are
+ // equivalent according to the rules for expressions [...]
+
+ // We do not actually substitute the parameter mappings into the
+ // constraint expressions, therefore the constraint expressions are
+ // the originals, and comparing them will suffice.
+ if (ConstraintExpr != Other.ConstraintExpr)
+ return false;
+
+ // Check that the parameter lists are identical
+ return hasMatchingParameterMapping(C, Other);
+ }
+};
+
+/// \brief A normalized constraint, as defined in C++ [temp.constr.normal], is
+/// either an atomic constraint, a conjunction of normalized constraints or a
+/// disjunction of normalized constraints.
+struct NormalizedConstraint {
+ enum CompoundConstraintKind { CCK_Conjunction, CCK_Disjunction };
+
+ using CompoundConstraint = llvm::PointerIntPair<
+ std::pair<NormalizedConstraint, NormalizedConstraint> *, 1,
+ CompoundConstraintKind>;
+
+ llvm::PointerUnion<AtomicConstraint *, CompoundConstraint> Constraint;
+
+ NormalizedConstraint(AtomicConstraint *C): Constraint{C} { };
+ NormalizedConstraint(ASTContext &C, NormalizedConstraint LHS,
+ NormalizedConstraint RHS, CompoundConstraintKind Kind)
+ : Constraint{CompoundConstraint{
+ new (C) std::pair<NormalizedConstraint, NormalizedConstraint>{LHS,
+ RHS},
+ Kind}} { };
+
+ CompoundConstraintKind getCompoundKind() const {
+ assert(!isAtomic() && "getCompoundKind called on atomic constraint.");
+ return Constraint.get<CompoundConstraint>().getInt();
+ }
+
+ bool isAtomic() const { return Constraint.is<AtomicConstraint *>(); }
+
+ NormalizedConstraint &getLHS() const {
+ assert(!isAtomic() && "getLHS called on atomic constraint.");
+ return Constraint.get<CompoundConstraint>().getPointer()->first;
+ }
+
+ NormalizedConstraint &getRHS() const {
+ assert(!isAtomic() && "getRHS called on atomic constraint.");
+ return Constraint.get<CompoundConstraint>().getPointer()->second;
+ }
+
+ AtomicConstraint *getAtomicConstraint() const {
+ assert(isAtomic() &&
+ "getAtomicConstraint called on non-atomic constraint.");
+ return Constraint.get<AtomicConstraint *>();
+ }
+
+ static llvm::Optional<NormalizedConstraint>
+ fromConstraintExprs(Sema &S, NamedDecl *D, ArrayRef<const Expr *> E) {
+ assert(E.size() != 0);
+ auto First = fromConstraintExpr(S, D, E[0]);
+ if (E.size() == 1)
+ return First;
+ auto Second = fromConstraintExpr(S, D, E[1]);
+ if (!Second)
+ return llvm::Optional<NormalizedConstraint>{};
+ llvm::Optional<NormalizedConstraint> Conjunction;
+ Conjunction.emplace(S.Context, std::move(*First), std::move(*Second),
+ CCK_Conjunction);
+ for (unsigned I = 2; I < E.size(); ++I) {
+ auto Next = fromConstraintExpr(S, D, E[I]);
+ if (!Next)
+ return llvm::Optional<NormalizedConstraint>{};
+ NormalizedConstraint NewConjunction(S.Context, std::move(*Conjunction),
+ std::move(*Next), CCK_Conjunction);
+ *Conjunction = std::move(NewConjunction);
+ }
+ return Conjunction;
+ }
+
+private:
+ static llvm::Optional<NormalizedConstraint> fromConstraintExpr(Sema &S,
+ NamedDecl *D,
+ const Expr *E);
+};
+
+static bool substituteParameterMappings(Sema &S, NormalizedConstraint &N,
+ ConceptDecl *Concept, ArrayRef<TemplateArgument> TemplateArgs,
+ const ASTTemplateArgumentListInfo *ArgsAsWritten) {
+ if (!N.isAtomic()) {
+ if (substituteParameterMappings(S, N.getLHS(), Concept, TemplateArgs,
+ ArgsAsWritten))
+ return true;
+ return substituteParameterMappings(S, N.getRHS(), Concept, TemplateArgs,
+ 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,
+ /*Depth=*/0, OccurringIndices);
+ Atomic.ParameterMapping.emplace();
+ Atomic.ParameterMapping->reserve(OccurringIndices.size());
+ for (unsigned I = 0, C = TemplateParams->size(); I != C; ++I)
+ if (OccurringIndices[I])
+ Atomic.ParameterMapping->push_back(
+ S.getIdentityTemplateArgumentLoc(TemplateParams->begin()[I],
+ // Here we assume we do not support things like
+ // template<typename A, typename B>
+ // concept C = ...;
+ //
+ // template<typename... Ts> requires C<Ts...>
+ // struct S { };
+ // The above currently yields a diagnostic.
+ // We still might have default arguments for concept parameters.
+ ArgsAsWritten->NumTemplateArgs > I ?
+ ArgsAsWritten->arguments()[I].getLocation() :
+ SourceLocation()));
+ }
+ Sema::InstantiatingTemplate Inst(
+ S, ArgsAsWritten->arguments().front().getSourceRange().getBegin(),
+ Sema::InstantiatingTemplate::ParameterMappingSubstitution{}, Concept,
+ SourceRange(ArgsAsWritten->arguments()[0].getSourceRange().getBegin(),
+ ArgsAsWritten->arguments().back().getSourceRange().getEnd()));
+ if (S.SubstTemplateArguments(*Atomic.ParameterMapping, MLTAL, SubstArgs))
+ return true;
+ std::copy(SubstArgs.arguments().begin(), SubstArgs.arguments().end(),
+ N.getAtomicConstraint()->ParameterMapping->begin());
+ return false;
+}
+
+llvm::Optional<NormalizedConstraint>
+NormalizedConstraint::fromConstraintExpr(Sema &S, NamedDecl *D, const Expr *E) {
+ assert(E != nullptr);
+
+ // C++ [temp.constr.normal]p1.1
+ // [...]
+ // - The normal form of an expression (E) is the normal form of E.
+ // [...]
+ E = E->IgnoreParenImpCasts();
+ if (auto *BO = dyn_cast<const BinaryOperator>(E)) {
+ if (BO->getOpcode() == BO_LAnd || BO->getOpcode() == BO_LOr) {
+ auto LHS = fromConstraintExpr(S, D, BO->getLHS());
+ if (!LHS)
+ return None;
+ auto RHS = fromConstraintExpr(S, D, BO->getRHS());
+ if (!RHS)
+ return None;
+
+ return NormalizedConstraint(
+ S.Context, *LHS, *RHS,
+ BO->getOpcode() == BO_LAnd ? CCK_Conjunction : CCK_Disjunction);
+ }
+ } else if (auto *CSE = dyn_cast<const ConceptSpecializationExpr>(E)) {
+ Optional<NormalizedConstraint> SubNF;
+ {
+ Sema::InstantiatingTemplate Inst(
+ S, CSE->getExprLoc(),
+ Sema::InstantiatingTemplate::ConstraintNormalization{}, D,
+ CSE->getSourceRange());
+ // C++ [temp.constr.normal]p1.1
+ // [...]
+ // The normal form of an id-expression of the form C<A1, A2, ..., AN>,
+ // where C names a concept, is the normal form of the
+ // constraint-expression of C, after substituting A1, A2, ..., AN for C’s
+ // respective template parameters in the parameter mappings in each atomic
+ // constraint. If any such substitution results in an invalid type or
+ // expression, the program is ill-formed; no diagnostic is required.
+ // [...]
+ SubNF = fromConstraintExpr(S, CSE->getNamedConcept(),
+ CSE->getNamedConcept()->getConstraintExpr());
+ if (!SubNF)
+ return None;
+ }
+
+ if (substituteParameterMappings(
+ S, *SubNF, CSE->getNamedConcept(),
+ CSE->getTemplateArguments(), CSE->getTemplateArgsAsWritten()))
+ return None;
+
+ return SubNF;
+ }
+ return NormalizedConstraint{new (S.Context) AtomicConstraint(S, E)};
+}
+
+} // namespace
+
+using NormalForm =
+ llvm::SmallVector<llvm::SmallVector<AtomicConstraint *, 2>, 4>;
+
+static NormalForm makeCNF(const NormalizedConstraint &Normalized) {
+ if (Normalized.isAtomic())
+ return {{Normalized.getAtomicConstraint()}};
+
+ NormalForm LCNF = makeCNF(Normalized.getLHS());
+ NormalForm RCNF = makeCNF(Normalized.getRHS());
+ if (Normalized.getCompoundKind() == NormalizedConstraint::CCK_Conjunction) {
+ LCNF.reserve(LCNF.size() + RCNF.size());
+ while (!RCNF.empty())
+ LCNF.push_back(RCNF.pop_back_val());
+ return LCNF;
+ }
+
+ // Disjunction
+ NormalForm Res;
+ Res.reserve(LCNF.size() * RCNF.size());
+ for (auto &LDisjunction : LCNF)
+ for (auto &RDisjunction : RCNF) {
+ NormalForm::value_type Combined;
+ Combined.reserve(LDisjunction.size() + RDisjunction.size());
+ std::copy(LDisjunction.begin(), LDisjunction.end(),
+ std::back_inserter(Combined));
+ std::copy(RDisjunction.begin(), RDisjunction.end(),
+ std::back_inserter(Combined));
+ Res.emplace_back(Combined);
+ }
+ return Res;
+}
+
+static NormalForm makeDNF(const NormalizedConstraint &Normalized) {
+ if (Normalized.isAtomic())
+ return {{Normalized.getAtomicConstraint()}};
+
+ NormalForm LDNF = makeDNF(Normalized.getLHS());
+ NormalForm RDNF = makeDNF(Normalized.getRHS());
+ if (Normalized.getCompoundKind() == NormalizedConstraint::CCK_Disjunction) {
+ LDNF.reserve(LDNF.size() + RDNF.size());
+ while (!RDNF.empty())
+ LDNF.push_back(RDNF.pop_back_val());
+ return LDNF;
+ }
+
+ // Conjunction
+ NormalForm Res;
+ Res.reserve(LDNF.size() * RDNF.size());
+ for (auto &LConjunction : LDNF) {
+ for (auto &RConjunction : RDNF) {
+ NormalForm::value_type Combined;
+ Combined.reserve(LConjunction.size() + RConjunction.size());
+ std::copy(LConjunction.begin(), LConjunction.end(),
+ std::back_inserter(Combined));
+ std::copy(RConjunction.begin(), RConjunction.end(),
+ std::back_inserter(Combined));
+ Res.emplace_back(Combined);
+ }
+ }
+ return Res;
+}
+
+static bool subsumes(Sema &S, NamedDecl *DP, ArrayRef<const Expr *> P,
+ NamedDecl *DQ, ArrayRef<const Expr *> Q, bool &Subsumes) {
+ // C++ [temp.constr.order] p2
+ // In order to determine if a constraint P subsumes a constraint Q, P is
+ // transformed into disjunctive normal form, and Q is transformed into
+ // conjunctive normal form. [...]
+ auto PNormalized = NormalizedConstraint::fromConstraintExprs(S, DP, P);
+ if (!PNormalized)
+ return true;
+ const NormalForm PDNF = makeDNF(*PNormalized);
+
+ auto QNormalized = NormalizedConstraint::fromConstraintExprs(S, DQ, Q);
+ if (!QNormalized)
+ return true;
+ const NormalForm QCNF = makeCNF(*QNormalized);
+
+ // C++ [temp.constr.order] p2
+ // Then, P subsumes Q if and only if, for every disjunctive clause Pi in the
+ // disjunctive normal form of P, Pi subsumes every conjunctive clause Qj in
+ // the conjuctive normal form of Q, where [...]
+ for (const auto &Pi : PDNF) {
+ for (const auto &Qj : QCNF) {
+ // C++ [temp.constr.order] p2
+ // - [...] a disjunctive clause Pi subsumes a conjunctive clause Qj if
+ // and only if there exists an atomic constraint Pia in Pi for which
+ // there exists an atomic constraint, Qjb, in Qj such that Pia
+ // subsumes Qjb.
+ bool Found = false;
+ for (const AtomicConstraint *Pia : Pi) {
+ for (const AtomicConstraint *Qjb : Qj) {
+ if (Pia->subsumes(S.Context, *Qjb)) {
+ Found = true;
+ break;
+ }
+ }
+ if (Found)
+ break;
+ }
+ if (!Found) {
+ Subsumes = false;
+ return false;
+ }
+ }
+ }
+ Subsumes = true;
+ return false;
+}
+
+bool Sema::IsAtLeastAsConstrained(NamedDecl *D1, ArrayRef<const Expr *> AC1,
+ NamedDecl *D2, ArrayRef<const Expr *> AC2,
+ bool &Result) {
+ if (AC1.empty()) {
+ Result = AC2.empty();
+ return false;
+ }
+ if (AC2.empty()) {
+ // TD1 has associated constraints and TD2 does not.
+ Result = true;
+ return false;
+ }
+
+ std::pair<NamedDecl *, NamedDecl *> Key{D1, D2};
+ auto CacheEntry = SubsumptionCache.find(Key);
+ if (CacheEntry != SubsumptionCache.end()) {
+ Result = CacheEntry->second;
+ return false;
+ }
+ if (subsumes(*this, D1, AC1, D2, AC2, Result))
+ return true;
+ SubsumptionCache.try_emplace(Key, Result);
+ return false;
}
\ No newline at end of file
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
old mode 100644
new mode 100755
index 6998955..ade8a5a
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -1120,11 +1120,11 @@
// Check that we have valid decl-specifiers specified.
auto CheckValidDeclSpecifiers = [this, &D] {
// C++ [temp.param]
- // p1
+ // p1
// template-parameter:
// ...
// parameter-declaration
- // p2
+ // p2
// ... A storage class shall not be specified in a template-parameter
// declaration.
// [dcl.typedef]p1:
@@ -3900,7 +3900,9 @@
}
if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
- Converted)) {
+ Converted) &&
+ (!Context.getLangOpts().ConceptsTS ||
+ !TemplateParams->hasAssociatedConstraints())) {
// C++ [temp.class.spec]p9b3:
//
// -- The argument list of the specialization shall not be identical
@@ -3919,8 +3921,8 @@
VarTemplateSpecializationDecl *PrevDecl = nullptr;
if (IsPartialSpecialization)
- // FIXME: Template parameter list matters too
- PrevDecl = VarTemplate->findPartialSpecialization(Converted, InsertPos);
+ PrevDecl = VarTemplate->findPartialSpecialization(Converted, TemplateParams,
+ InsertPos);
else
PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos);
@@ -5273,12 +5275,16 @@
bool PackExpansionIntoNonPack =
NewArgs[ArgIdx].getArgument().isPackExpansion() &&
(!(*Param)->isTemplateParameterPack() || getExpandedPackSize(*Param));
- if (PackExpansionIntoNonPack && isa<TypeAliasTemplateDecl>(Template)) {
+ if (PackExpansionIntoNonPack && (isa<TypeAliasTemplateDecl>(Template) ||
+ isa<ConceptDecl>(Template))) {
// Core issue 1430: we have a pack expansion as an argument to an
// alias template, and it's not part of a parameter pack. This
// can't be canonicalized, so reject it now.
+ // As for concepts - we cannot normalize constraints where this
+ // situation exists.
Diag(NewArgs[ArgIdx].getLocation(),
- diag::err_alias_template_expansion_into_fixed_list)
+ diag::err_template_expansion_into_fixed_list)
+ << (isa<ConceptDecl>(Template) ? 1 : 0)
<< NewArgs[ArgIdx].getSourceRange();
Diag((*Param)->getLocation(), diag::note_template_param_here);
return true;
@@ -7112,6 +7118,7 @@
bool Complain,
Sema::TemplateParameterListEqualKind Kind,
SourceLocation TemplateArgLoc) {
+ // TODO: Concepts: Check constrained-parameter constraints here.
// Check the actual kind (type, non-type, template).
if (Old->getKind() != New->getKind()) {
if (Complain) {
@@ -7813,8 +7820,9 @@
ClassTemplateSpecializationDecl *PrevDecl = nullptr;
if (isPartialSpecialization)
- // FIXME: Template parameter list matters, too
- PrevDecl = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
+ PrevDecl = ClassTemplate->findPartialSpecialization(Converted,
+ TemplateParams,
+ InsertPos);
else
PrevDecl = ClassTemplate->findSpecialization(Converted, InsertPos);
@@ -7838,7 +7846,9 @@
Converted);
if (Context.hasSameType(CanonType,
- ClassTemplate->getInjectedClassNameSpecialization())) {
+ ClassTemplate->getInjectedClassNameSpecialization()) &&
+ (!Context.getLangOpts().ConceptsTS ||
+ !TemplateParams->hasAssociatedConstraints())) {
// C++ [temp.class.spec]p9b3:
//
// -- The argument list of the specialization shall not be identical
diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
index 46d9231..822ea12 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -24,6 +24,7 @@
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/NestedNameSpecifier.h"
+#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/TemplateBase.h"
#include "clang/AST/TemplateName.h"
#include "clang/AST/Type.h"
@@ -2501,6 +2502,30 @@
llvm_unreachable("Invalid TemplateArgument Kind!");
}
+TemplateArgumentLoc
+Sema::getIdentityTemplateArgumentLoc(Decl *TemplateParm,
+ SourceLocation Location) {
+ if (auto *TTP = dyn_cast<TemplateTypeParmDecl>(TemplateParm))
+ return getTrivialTemplateArgumentLoc(
+ TemplateArgument(
+ Context.getTemplateTypeParmType(TTP->getDepth(), TTP->getIndex(),
+ TTP->isParameterPack(), TTP)),
+ QualType(), Location.isValid() ? Location : TTP->getLocation());
+ else if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(TemplateParm))
+ return getTrivialTemplateArgumentLoc(TemplateArgument(TemplateName(TTP)),
+ QualType(),
+ Location.isValid() ? Location :
+ TTP->getLocation());
+ auto *NTTP = cast<NonTypeTemplateParmDecl>(TemplateParm);
+ CXXScopeSpec SS;
+ DeclarationNameInfo Info(NTTP->getDeclName(),
+ Location.isValid() ? Location : NTTP->getLocation());
+ Expr *E = BuildDeclarationNameExpr(SS, Info, NTTP).get();
+ return getTrivialTemplateArgumentLoc(TemplateArgument(E), NTTP->getType(),
+ Location.isValid() ? Location :
+ NTTP->getLocation());
+}
+
/// Convert the given deduced template argument and add it to the set of
/// fully-converted template arguments.
static bool
@@ -2591,23 +2616,6 @@
return ConvertArg(Arg, 0);
}
-template<typename TemplateDeclT>
-static Sema::TemplateDeductionResult
-CheckDeducedArgumentConstraints(Sema& S, TemplateDeclT *Template,
- ArrayRef<TemplateArgument> DeducedArgs,
- TemplateDeductionInfo &Info) {
- llvm::SmallVector<const Expr *, 3> AssociatedConstraints;
- Template->getAssociatedConstraints(AssociatedConstraints);
- if (S.CheckConstraintSatisfaction(Template, AssociatedConstraints,
- DeducedArgs, Info.getLocation(),
- Info.AssociatedConstraintsSatisfaction) ||
- !Info.AssociatedConstraintsSatisfaction.IsSatisfied) {
- Info.reset(TemplateArgumentList::CreateCopy(S.Context, DeducedArgs));
- return Sema::TDK_ConstraintsNotSatisfied;
- }
- return Sema::TDK_Success;
-}
-
// FIXME: This should not be a template, but
// ClassTemplatePartialSpecializationDecl sadly does not derive from
// TemplateDecl.
@@ -2705,10 +2713,6 @@
// If we get here, we successfully used the default template argument.
}
- if (Sema::TemplateDeductionResult Result
- = CheckDeducedArgumentConstraints(S, Template, Builder, Info))
- return Result;
-
return Sema::TDK_Success;
}
@@ -2730,6 +2734,23 @@
static constexpr bool value = true;
};
+template<typename TemplateDeclT>
+static Sema::TemplateDeductionResult
+CheckDeducedArgumentConstraints(Sema& S, TemplateDeclT *Template,
+ ArrayRef<TemplateArgument> DeducedArgs,
+ TemplateDeductionInfo& Info) {
+ llvm::SmallVector<const Expr *, 3> AssociatedConstraints;
+ Template->getAssociatedConstraints(AssociatedConstraints);
+ if (S.CheckConstraintSatisfaction(Template, AssociatedConstraints,
+ DeducedArgs, Info.getLocation(),
+ Info.AssociatedConstraintsSatisfaction) ||
+ !Info.AssociatedConstraintsSatisfaction.IsSatisfied) {
+ Info.reset(TemplateArgumentList::CreateCopy(S.Context, DeducedArgs));
+ return Sema::TDK_ConstraintsNotSatisfied;
+ }
+ return Sema::TDK_Success;
+}
+
/// Complete template argument deduction for a partial specialization.
template <typename T>
static typename std::enable_if<IsPartialSpecialization<T>::value,
@@ -2811,6 +2832,9 @@
if (Trap.hasErrorOccurred())
return Sema::TDK_SubstitutionFailure;
+ if (auto Result = CheckDeducedArgumentConstraints(S, Partial, Builder, Info))
+ return Result;
+
return Sema::TDK_Success;
}
@@ -2853,6 +2877,10 @@
if (Trap.hasErrorOccurred())
return Sema::TDK_SubstitutionFailure;
+ if (auto Result = CheckDeducedArgumentConstraints(S, Template, Builder,
+ Info))
+ return Result;
+
return Sema::TDK_Success;
}
@@ -3364,6 +3392,11 @@
PartialOverloading))
return Result;
+ if (TemplateDeductionResult Result
+ = CheckDeducedArgumentConstraints(*this, FunctionTemplate, Builder,
+ Info))
+ return Result;
+
// C++ [temp.deduct.call]p10: [DR1391]
// If deduction succeeds for all parameters that contain
// template-parameters that participate in template argument deduction,
@@ -4930,6 +4963,21 @@
TemplatePartialOrderingContext TPOC,
unsigned NumCallArguments1,
unsigned NumCallArguments2) {
+
+ auto JudgeByConstraints = [&] () -> FunctionTemplateDecl * {
+ llvm::SmallVector<const Expr *, 3> AC1, AC2;
+ FT1->getAssociatedConstraints(AC1);
+ FT2->getAssociatedConstraints(AC2);
+ bool AtLeastAsConstrained1, AtLeastAsConstrained2;
+ if (IsAtLeastAsConstrained(FT1, AC1, FT2, AC2, AtLeastAsConstrained1))
+ return nullptr;
+ if (IsAtLeastAsConstrained(FT2, AC2, FT1, AC1, AtLeastAsConstrained2))
+ return nullptr;
+ if (AtLeastAsConstrained1 == AtLeastAsConstrained2)
+ return nullptr;
+ return AtLeastAsConstrained1 ? FT1 : FT2;
+ };
+
bool Better1 = isAtLeastAsSpecializedAs(*this, Loc, FT1, FT2, TPOC,
NumCallArguments1);
bool Better2 = isAtLeastAsSpecializedAs(*this, Loc, FT2, FT1, TPOC,
@@ -4939,7 +4987,7 @@
return Better1 ? FT1 : FT2;
if (!Better1 && !Better2) // Neither is better than the other
- return nullptr;
+ return JudgeByConstraints();
// FIXME: This mimics what GCC implements, but doesn't match up with the
// proposed resolution for core issue 692. This area needs to be sorted out,
@@ -4949,7 +4997,7 @@
if (Variadic1 != Variadic2)
return Variadic1? FT2 : FT1;
- return nullptr;
+ return JudgeByConstraints();
}
/// Determine if the two templates are equivalent.
@@ -5074,7 +5122,6 @@
static bool isAtLeastAsSpecializedAs(Sema &S, QualType T1, QualType T2,
TemplateLikeDecl *P2,
TemplateDeductionInfo &Info) {
- // TODO: Concepts: Regard constraints
// C++ [temp.class.order]p1:
// For two class template partial specializations, the first is at least as
// specialized as the second if, given the following rewrite to two
@@ -5145,8 +5192,21 @@
bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info);
bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info);
- if (Better1 == Better2)
- return nullptr;
+ if (!Better1 && !Better2)
+ return nullptr;
+ if (Better1 && Better2) {
+ llvm::SmallVector<const Expr *, 3> AC1, AC2;
+ PS1->getAssociatedConstraints(AC1);
+ PS2->getAssociatedConstraints(AC2);
+ bool AtLeastAsConstrained1, AtLeastAsConstrained2;
+ if (IsAtLeastAsConstrained(PS1, AC1, PS2, AC2, AtLeastAsConstrained1))
+ return nullptr;
+ if (IsAtLeastAsConstrained(PS2, AC2, PS1, AC1, AtLeastAsConstrained2))
+ return nullptr;
+ if (AtLeastAsConstrained1 == AtLeastAsConstrained2)
+ return nullptr;
+ return AtLeastAsConstrained1 ? PS1 : PS2;
+ }
return Better1 ? PS1 : PS2;
}
@@ -5158,11 +5218,22 @@
QualType PartialT = Spec->getInjectedSpecializationType();
if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info))
return false;
- if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) {
- Info.clearSFINAEDiagnostic();
+ if (!isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info))
+ return true;
+ Info.clearSFINAEDiagnostic();
+ llvm::SmallVector<const Expr *, 3> PrimaryAC, SpecAC;
+ Primary->getAssociatedConstraints(PrimaryAC);
+ Spec->getAssociatedConstraints(SpecAC);
+ bool AtLeastAsConstrainedPrimary, AtLeastAsConstrainedSpec;
+ if (IsAtLeastAsConstrained(Spec, SpecAC, Primary, PrimaryAC,
+ AtLeastAsConstrainedSpec))
return false;
- }
- return true;
+ if (!AtLeastAsConstrainedSpec)
+ return false;
+ if (IsAtLeastAsConstrained(Primary, PrimaryAC, Spec, SpecAC,
+ AtLeastAsConstrainedPrimary))
+ return false;
+ return !AtLeastAsConstrainedPrimary;
}
VarTemplatePartialSpecializationDecl *
@@ -5185,8 +5256,22 @@
bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info);
bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info);
- if (Better1 == Better2)
+ if (!Better1 && !Better2)
return nullptr;
+ if (Better1 && Better2) {
+ llvm::SmallVector<const Expr *, 3> AC1, AC2;
+ PS1->getAssociatedConstraints(AC1);
+ PS2->getAssociatedConstraints(AC2);
+ bool AtLeastAsConstrained1, AtLeastAsConstrained2;
+ if (IsAtLeastAsConstrained(PS1, AC1, PS2, AC2, AtLeastAsConstrained1))
+ return nullptr;
+ if (IsAtLeastAsConstrained(PS2, AC2, PS1, AC1, AtLeastAsConstrained2))
+ return nullptr;
+ if (AtLeastAsConstrained1 == AtLeastAsConstrained2) {
+ return nullptr;
+ }
+ return AtLeastAsConstrained1 ? PS1 : PS2;
+ }
return Better1 ? PS1 : PS2;
}
@@ -5206,13 +5291,25 @@
CanonTemplate, PrimaryArgs);
QualType PartialT = Context.getTemplateSpecializationType(
CanonTemplate, Spec->getTemplateArgs().asArray());
+
if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info))
return false;
- if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) {
- Info.clearSFINAEDiagnostic();
+ if (!isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info))
+ return true;
+ Info.clearSFINAEDiagnostic();
+ llvm::SmallVector<const Expr *, 3> PrimaryAC, SpecAC;
+ Primary->getAssociatedConstraints(PrimaryAC);
+ Spec->getAssociatedConstraints(SpecAC);
+ bool AtLeastAsConstrainedPrimary, AtLeastAsConstrainedSpec;
+ if (IsAtLeastAsConstrained(Spec, SpecAC, Primary, PrimaryAC,
+ AtLeastAsConstrainedSpec))
return false;
- }
- return true;
+ if (!AtLeastAsConstrainedSpec)
+ return false;
+ if (IsAtLeastAsConstrained(Primary, PrimaryAC, Spec, SpecAC,
+ AtLeastAsConstrainedPrimary))
+ return false;
+ return !AtLeastAsConstrainedPrimary;
}
bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs(
@@ -5278,6 +5375,47 @@
return isAtLeastAsSpecializedAs(*this, PType, AType, AArg, Info);
}
+struct OccurringTemplateParameterFinder :
+ RecursiveASTVisitor<OccurringTemplateParameterFinder> {
+ llvm::SmallBitVector &OccurringIndices;
+
+ OccurringTemplateParameterFinder(llvm::SmallBitVector &OccurringIndices)
+ : OccurringIndices(OccurringIndices) { }
+
+ bool VisitTemplateTypeParmType(TemplateTypeParmType *T) {
+ assert(T->getDepth() == 0 && "This assumes that we allow concepts at "
+ "namespace scope only");
+ noteParameter(T->getIndex());
+ return true;
+ }
+
+ bool TraverseTemplateName(TemplateName Template) {
+ if (auto *TTP =
+ dyn_cast<TemplateTemplateParmDecl>(Template.getAsTemplateDecl())) {
+ assert(TTP->getDepth() == 0 && "This assumes that we allow concepts at "
+ "namespace scope only");
+ noteParameter(TTP->getIndex());
+ }
+ RecursiveASTVisitor<OccurringTemplateParameterFinder>::
+ TraverseTemplateName(Template);
+ return true;
+ }
+
+ bool VisitDeclRefExpr(DeclRefExpr *E) {
+ if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(E->getDecl())) {
+ assert(NTTP->getDepth() == 0 && "This assumes that we allow concepts at "
+ "namespace scope only");
+ noteParameter(NTTP->getIndex());
+ }
+ return true;
+ }
+
+protected:
+ void noteParameter(unsigned Index) {
+ OccurringIndices.set(Index);
+ }
+};
+
/// Mark the template parameters that are used by the given
/// expression.
static void
@@ -5286,6 +5424,11 @@
bool OnlyDeduced,
unsigned Depth,
llvm::SmallBitVector &Used) {
+ if (!OnlyDeduced) {
+ OccurringTemplateParameterFinder(Used).TraverseStmt(const_cast<Expr *>(E));
+ return;
+ }
+
// We can deduce from a pack expansion.
if (const PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(E))
E = Expansion->getPattern();
@@ -5304,8 +5447,6 @@
break;
}
- // FIXME: if !OnlyDeduced, we have to walk the whole subexpression to
- // find other occurrences of template parameters.
const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E);
if (!DRE)
return;
@@ -5685,6 +5826,20 @@
}
}
+/// Mark which template parameters are used in a given expression.
+///
+/// \param E the expression from which template parameters will be deduced.
+///
+/// \param Used a bit vector whose elements will be set to \c true
+/// to indicate when the corresponding template parameter will be
+/// deduced.
+void
+Sema::MarkUsedTemplateParameters(const Expr *E, bool OnlyDeduced,
+ unsigned Depth,
+ llvm::SmallBitVector &Used) {
+ ::MarkUsedTemplateParameters(Context, E, OnlyDeduced, Depth, Used);
+}
+
/// Mark which template parameters can be deduced from a given
/// template argument list.
///
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 6db8eb3..770c07d 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -207,6 +207,8 @@
case DefiningSynthesizedFunction:
case ExceptionSpecEvaluation:
case ConstraintSubstitution:
+ case ParameterMappingSubstitution:
+ case ConstraintNormalization:
case RewritingOperatorAsSpaceship:
return false;
@@ -380,6 +382,22 @@
PointOfInstantiation, InstantiationRange, Template, nullptr,
{}, &DeductionInfo) {}
+Sema::InstantiatingTemplate::InstantiatingTemplate(
+ Sema &SemaRef, SourceLocation PointOfInstantiation,
+ ConstraintNormalization, NamedDecl *Template,
+ SourceRange InstantiationRange)
+ : InstantiatingTemplate(
+ SemaRef, CodeSynthesisContext::ConstraintNormalization,
+ PointOfInstantiation, InstantiationRange, Template) {}
+
+Sema::InstantiatingTemplate::InstantiatingTemplate(
+ Sema &SemaRef, SourceLocation PointOfInstantiation,
+ ParameterMappingSubstitution, NamedDecl *Template,
+ SourceRange InstantiationRange)
+ : InstantiatingTemplate(
+ SemaRef, CodeSynthesisContext::ParameterMappingSubstitution,
+ PointOfInstantiation, InstantiationRange, Template) {}
+
void Sema::pushCodeSynthesisContext(CodeSynthesisContext Ctx) {
Ctx.SavedInNonInstantiationSFINAEContext = InNonInstantiationSFINAEContext;
InNonInstantiationSFINAEContext = false;
@@ -733,6 +751,17 @@
diag::note_constraint_substitution_here)
<< Active->InstantiationRange;
break;
+ case CodeSynthesisContext::ConstraintNormalization:
+ Diags.Report(Active->PointOfInstantiation,
+ diag::note_constraint_normalization_here)
+ << cast<NamedDecl>(Active->Entity)->getName()
+ << Active->InstantiationRange;
+ break;
+ case CodeSynthesisContext::ParameterMappingSubstitution:
+ Diags.Report(Active->PointOfInstantiation,
+ diag::note_parameter_mapping_substitution_here)
+ << Active->InstantiationRange;
+ break;
}
}
}
@@ -757,6 +786,8 @@
case CodeSynthesisContext::DefaultFunctionArgumentInstantiation:
case CodeSynthesisContext::ExceptionSpecInstantiation:
case CodeSynthesisContext::ConstraintsCheck:
+ case CodeSynthesisContext::ParameterMappingSubstitution:
+ case CodeSynthesisContext::ConstraintNormalization:
// This is a template instantiation, so there is no SFINAE.
return None;
@@ -2926,6 +2957,17 @@
return Instantiator.TransformStmt(S);
}
+bool Sema::SubstTemplateArguments(
+ ArrayRef<TemplateArgumentLoc> Args,
+ const MultiLevelTemplateArgumentList &TemplateArgs,
+ TemplateArgumentListInfo &Out) {
+ TemplateInstantiator Instantiator(*this, TemplateArgs,
+ SourceLocation(),
+ DeclarationName());
+ return Instantiator.TransformTemplateArguments(Args.begin(), Args.end(),
+ Out);
+}
+
ExprResult
Sema::SubstExpr(Expr *E, const MultiLevelTemplateArgumentList &TemplateArgs) {
if (!E)
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
old mode 100644
new mode 100755
index 0bff074..a8fc77f
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3706,7 +3706,8 @@
// in the member template's set of class template partial specializations.
void *InsertPos = nullptr;
ClassTemplateSpecializationDecl *PrevDecl
- = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
+ = ClassTemplate->findPartialSpecialization(Converted, InstParams,
+ InsertPos);
// Build the canonical type that describes the converted template
// arguments of the class template partial specialization.
@@ -3830,7 +3831,7 @@
// in the member template's set of variable template partial specializations.
void *InsertPos = nullptr;
VarTemplateSpecializationDecl *PrevDecl =
- VarTemplate->findPartialSpecialization(Converted, InsertPos);
+ VarTemplate->findPartialSpecialization(Converted, InstParams, InsertPos);
// Build the canonical type that describes the converted template
// arguments of the variable template partial specialization.