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Implement C++ [temp.func.order]p5 more directly, by passing down the 

number of explicit call arguments. This actually fixes an erroneous
test for [temp.deduct.partial]p11, where we were considering
parameters corresponding to arguments beyond those that were
explicitly provided.

llvm-svn: 123244
This commit is contained in:
Douglas Gregor 2011-01-11 17:34:58 +00:00
parent d30de95520
commit b837ea4eee
5 changed files with 156 additions and 157 deletions
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4
clang/include/clang/Sema/Sema.h
View File

@ -3510,10 +3510,12 @@ public:
FunctionTemplateDecl *getMoreSpecializedTemplate(FunctionTemplateDecl *FT1,
FunctionTemplateDecl *FT2,
SourceLocation Loc,
TemplatePartialOrderingContext TPOC);
TemplatePartialOrderingContext TPOC,
unsigned NumCallArguments);
UnresolvedSetIterator getMostSpecialized(UnresolvedSetIterator SBegin,
UnresolvedSetIterator SEnd,
TemplatePartialOrderingContext TPOC,
unsigned NumCallArguments,
SourceLocation Loc,
const PartialDiagnostic &NoneDiag,
const PartialDiagnostic &AmbigDiag,

5
clang/lib/Sema/SemaOverload.cpp
View File

@ -5897,7 +5897,8 @@ isBetterOverloadCandidate(Sema &S,
Cand2.Function->getPrimaryTemplate(),
Loc,
isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion
: TPOC_Call))
: TPOC_Call,
NumArgs))
return BetterTemplate == Cand1.Function->getPrimaryTemplate();
// -- the context is an initialization by user-defined conversion
@ -6926,7 +6927,7 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
UnresolvedSetIterator Result =
getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(),
TPOC_Other, From->getLocStart(),
TPOC_Other, 0, From->getLocStart(),
PDiag(),
PDiag(diag::err_addr_ovl_ambiguous)
<< Matches[0].second->getDeclName(),

4
clang/lib/Sema/SemaTemplate.cpp
View File

@ -4846,7 +4846,7 @@ Sema::CheckFunctionTemplateSpecialization(FunctionDecl *FD,
// Find the most specialized function template.
UnresolvedSetIterator Result
= getMostSpecialized(Candidates.begin(), Candidates.end(),
TPOC_Other, FD->getLocation(),
TPOC_Other, 0, FD->getLocation(),
PDiag(diag::err_function_template_spec_no_match)
<< FD->getDeclName(),
PDiag(diag::err_function_template_spec_ambiguous)
@ -5668,7 +5668,7 @@ DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
// Find the most specialized function template specialization.
UnresolvedSetIterator Result
= getMostSpecialized(Matches.begin(), Matches.end(), TPOC_Other,
= getMostSpecialized(Matches.begin(), Matches.end(), TPOC_Other, 0,
D.getIdentifierLoc(),
PDiag(diag::err_explicit_instantiation_not_known) << Name,
PDiag(diag::err_explicit_instantiation_ambiguous) << Name,

294
clang/lib/Sema/SemaTemplateDeduction.cpp
View File

@ -84,6 +84,15 @@ DeduceTemplateArguments(Sema &S,
TemplateDeductionInfo &Info,
llvm::SmallVectorImpl<DeducedTemplateArgument> &Deduced);
/// \brief Stores the result of comparing the qualifiers of two types, used
/// when
enum DeductionQualifierComparison {
NeitherMoreQualified = 0,
ParamMoreQualified,
ArgMoreQualified
};
static Sema::TemplateDeductionResult
DeduceTemplateArguments(Sema &S,
TemplateParameterList *TemplateParams,
@ -91,7 +100,10 @@ DeduceTemplateArguments(Sema &S,
QualType Arg,
TemplateDeductionInfo &Info,
llvm::SmallVectorImpl<DeducedTemplateArgument> &Deduced,
unsigned TDF);
unsigned TDF,
bool PartialOrdering = false,
llvm::SmallVectorImpl<DeductionQualifierComparison> *
QualifierComparisons = 0);
static Sema::TemplateDeductionResult
DeduceTemplateArguments(Sema &S,
@ -621,6 +633,13 @@ FinishArgumentPackDeduction(Sema &S,
/// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe
/// how template argument deduction is performed.
///
/// \param PartialOrdering If true, we are performing template argument
/// deduction for during partial ordering for a call
/// (C++0x [temp.deduct.partial]).
///
/// \param QualifierComparisons If we're performing template argument deduction
/// in the context of partial ordering, the set of qualifier comparisons.
///
/// \returns the result of template argument deduction so far. Note that a
/// "success" result means that template argument deduction has not yet failed,
/// but it may still fail, later, for other reasons.
@ -631,7 +650,10 @@ DeduceTemplateArguments(Sema &S,
const QualType *Args, unsigned NumArgs,
TemplateDeductionInfo &Info,
llvm::SmallVectorImpl<DeducedTemplateArgument> &Deduced,
unsigned TDF) {
unsigned TDF,
bool PartialOrdering = false,
llvm::SmallVectorImpl<DeductionQualifierComparison> *
QualifierComparisons = 0) {
// Fast-path check to see if we have too many/too few arguments.
if (NumParams != NumArgs &&
!(NumParams && isa<PackExpansionType>(Params[NumParams - 1])) &&
@ -655,11 +677,14 @@ DeduceTemplateArguments(Sema &S,
if (ArgIdx >= NumArgs)
return Sema::TDK_NonDeducedMismatch;
if (Sema::TemplateDeductionResult Result
= DeduceTemplateArguments(S, TemplateParams,
Params[ParamIdx],
Args[ArgIdx],
Info, Deduced, TDF))
= DeduceTemplateArguments(S, TemplateParams,
Params[ParamIdx],
Args[ArgIdx],
Info, Deduced, TDF,
PartialOrdering,
QualifierComparisons))
return Result;
++ArgIdx;
@ -716,7 +741,8 @@ DeduceTemplateArguments(Sema &S,
// Deduce template arguments from the pattern.
if (Sema::TemplateDeductionResult Result
= DeduceTemplateArguments(S, TemplateParams, Pattern, Args[ArgIdx],
Info, Deduced))
Info, Deduced, PartialOrdering,
QualifierComparisons))
return Result;
// Capture the deduced template arguments for each parameter pack expanded
@ -765,6 +791,12 @@ DeduceTemplateArguments(Sema &S,
/// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe
/// how template argument deduction is performed.
///
/// \param PartialOrdering Whether we're performing template argument deduction
/// in the context of partial ordering (C++0x [temp.deduct.partial]).
///
/// \param QualifierComparisons If we're performing template argument deduction
/// in the context of partial ordering, the set of qualifier comparisons.
///
/// \returns the result of template argument deduction so far. Note that a
/// "success" result means that template argument deduction has not yet failed,
/// but it may still fail, later, for other reasons.
@ -774,24 +806,68 @@ DeduceTemplateArguments(Sema &S,
QualType ParamIn, QualType ArgIn,
TemplateDeductionInfo &Info,
llvm::SmallVectorImpl<DeducedTemplateArgument> &Deduced,
unsigned TDF) {
unsigned TDF,
bool PartialOrdering,
llvm::SmallVectorImpl<DeductionQualifierComparison> *QualifierComparisons) {
// We only want to look at the canonical types, since typedefs and
// sugar are not part of template argument deduction.
QualType Param = S.Context.getCanonicalType(ParamIn);
QualType Arg = S.Context.getCanonicalType(ArgIn);
// C++0x [temp.deduct.call]p4 bullet 1:
// - If the original P is a reference type, the deduced A (i.e., the type
// referred to by the reference) can be more cv-qualified than the
// transformed A.
if (TDF & TDF_ParamWithReferenceType) {
Qualifiers Quals;
QualType UnqualParam = S.Context.getUnqualifiedArrayType(Param, Quals);
Quals.setCVRQualifiers(Quals.getCVRQualifiers() &
Arg.getCVRQualifiersThroughArrayTypes());
Param = S.Context.getQualifiedType(UnqualParam, Quals);
if (PartialOrdering) {
// C++0x [temp.deduct.partial]p5:
// Before the partial ordering is done, certain transformations are
// performed on the types used for partial ordering:
// - If P is a reference type, P is replaced by the type referred to.
const ReferenceType *ParamRef = Param->getAs<ReferenceType>();
if (ParamRef)
Param = ParamRef->getPointeeType();
// - If A is a reference type, A is replaced by the type referred to.
const ReferenceType *ArgRef = Arg->getAs<ReferenceType>();
if (ArgRef)
Arg = ArgRef->getPointeeType();
if (QualifierComparisons && ParamRef && ArgRef) {
// C++0x [temp.deduct.partial]p6:
// If both P and A were reference types (before being replaced with the
// type referred to above), determine which of the two types (if any) is
// more cv-qualified than the other; otherwise the types are considered
// to be equally cv-qualified for partial ordering purposes. The result
// of this determination will be used below.
//
// We save this information for later, using it only when deduction
// succeeds in both directions.
DeductionQualifierComparison QualifierResult = NeitherMoreQualified;
if (Param.isMoreQualifiedThan(Arg))
QualifierResult = ParamMoreQualified;
else if (Arg.isMoreQualifiedThan(Param))
QualifierResult = ArgMoreQualified;
QualifierComparisons->push_back(QualifierResult);
}
// C++0x [temp.deduct.partial]p7:
// Remove any top-level cv-qualifiers:
// - If P is a cv-qualified type, P is replaced by the cv-unqualified
// version of P.
Param = Param.getUnqualifiedType();
// - If A is a cv-qualified type, A is replaced by the cv-unqualified
// version of A.
Arg = Arg.getUnqualifiedType();
} else {
// C++0x [temp.deduct.call]p4 bullet 1:
// - If the original P is a reference type, the deduced A (i.e., the type
// referred to by the reference) can be more cv-qualified than the
// transformed A.
if (TDF & TDF_ParamWithReferenceType) {
Qualifiers Quals;
QualType UnqualParam = S.Context.getUnqualifiedArrayType(Param, Quals);
Quals.setCVRQualifiers(Quals.getCVRQualifiers() &
Arg.getCVRQualifiersThroughArrayTypes());
Param = S.Context.getQualifiedType(UnqualParam, Quals);
}
}
// If the parameter type is not dependent, there is nothing to deduce.
if (!Param->isDependentType()) {
if (!(TDF & TDF_SkipNonDependent) && Param != Arg)
@ -2300,7 +2376,7 @@ static bool AdjustFunctionParmAndArgTypesForDeduction(Sema &S,
// for type deduction.
ParamType = ParamRefType->getPointeeType();
}
// Overload sets usually make this parameter an undeduced
// context, but there are sometimes special circumstances.
if (ArgType == S.Context.OverloadTy) {
@ -2786,90 +2862,6 @@ Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
QualType(), Specialization, Info);
}
/// \brief Stores the result of comparing the qualifiers of two types.
enum DeductionQualifierComparison {
NeitherMoreQualified = 0,
ParamMoreQualified,
ArgMoreQualified
};
/// \brief Deduce the template arguments during partial ordering by comparing
/// the parameter type and the argument type (C++0x [temp.deduct.partial]).
///
/// \param S the semantic analysis object within which we are deducing
///
/// \param TemplateParams the template parameters that we are deducing
///
/// \param ParamIn the parameter type
///
/// \param ArgIn the argument type
///
/// \param Info information about the template argument deduction itself
///
/// \param Deduced the deduced template arguments
///
/// \returns the result of template argument deduction so far. Note that a
/// "success" result means that template argument deduction has not yet failed,
/// but it may still fail, later, for other reasons.
static Sema::TemplateDeductionResult
DeduceTemplateArgumentsDuringPartialOrdering(Sema &S,
TemplateParameterList *TemplateParams,
QualType ParamIn, QualType ArgIn,
TemplateDeductionInfo &Info,
llvm::SmallVectorImpl<DeducedTemplateArgument> &Deduced,
llvm::SmallVectorImpl<DeductionQualifierComparison> *QualifierComparisons) {
CanQualType Param = S.Context.getCanonicalType(ParamIn);
CanQualType Arg = S.Context.getCanonicalType(ArgIn);
// C++0x [temp.deduct.partial]p5:
// Before the partial ordering is done, certain transformations are
// performed on the types used for partial ordering:
// - If P is a reference type, P is replaced by the type referred to.
CanQual<ReferenceType> ParamRef = Param->getAs<ReferenceType>();
if (!ParamRef.isNull())
Param = ParamRef->getPointeeType();
// - If A is a reference type, A is replaced by the type referred to.
CanQual<ReferenceType> ArgRef = Arg->getAs<ReferenceType>();
if (!ArgRef.isNull())
Arg = ArgRef->getPointeeType();
if (QualifierComparisons && !ParamRef.isNull() && !ArgRef.isNull()) {
// C++0x [temp.deduct.partial]p6:
// If both P and A were reference types (before being replaced with the
// type referred to above), determine which of the two types (if any) is
// more cv-qualified than the other; otherwise the types are considered to
// be equally cv-qualified for partial ordering purposes. The result of this
// determination will be used below.
//
// We save this information for later, using it only when deduction
// succeeds in both directions.
DeductionQualifierComparison QualifierResult = NeitherMoreQualified;
if (Param.isMoreQualifiedThan(Arg))
QualifierResult = ParamMoreQualified;
else if (Arg.isMoreQualifiedThan(Param))
QualifierResult = ArgMoreQualified;
QualifierComparisons->push_back(QualifierResult);
}
// C++0x [temp.deduct.partial]p7:
// Remove any top-level cv-qualifiers:
// - If P is a cv-qualified type, P is replaced by the cv-unqualified
// version of P.
Param = Param.getUnqualifiedType();
// - If A is a cv-qualified type, A is replaced by the cv-unqualified
// version of A.
Arg = Arg.getUnqualifiedType();
// C++0x [temp.deduct.partial]p8:
// Using the resulting types P and A the deduction is then done as
// described in 14.9.2.5. If deduction succeeds for a given type, the type
// from the argument template is considered to be at least as specialized
// as the type from the parameter template.
return DeduceTemplateArguments(S, TemplateParams, Param, Arg, Info,
Deduced, TDF_None);
}
static void
MarkUsedTemplateParameters(Sema &SemaRef, QualType T,
bool OnlyDeduced,
@ -2907,6 +2899,7 @@ static bool isAtLeastAsSpecializedAs(Sema &S,
FunctionTemplateDecl *FT1,
FunctionTemplateDecl *FT2,
TemplatePartialOrderingContext TPOC,
unsigned NumCallArguments,
llvm::SmallVectorImpl<DeductionQualifierComparison> *QualifierComparisons) {
FunctionDecl *FD1 = FT1->getTemplatedDecl();
FunctionDecl *FD2 = FT2->getTemplatedDecl();
@ -2951,7 +2944,7 @@ static bool isAtLeastAsSpecializedAs(Sema &S,
unsigned Skip1 = !S.getLangOptions().CPlusPlus0x &&
IsNonStatic2 && !IsNonStatic1;
if (S.getLangOptions().CPlusPlus0x && IsNonStatic1 && !IsNonStatic2)
MaybeAddImplicitObjectParameterType(S.Context, Method1, Args1);
MaybeAddImplicitObjectParameterType(S.Context, Method1, Args1);
Args1.insert(Args1.end(),
Proto1->arg_type_begin() + Skip1, Proto1->arg_type_end());
@ -2962,16 +2955,18 @@ static bool isAtLeastAsSpecializedAs(Sema &S,
MaybeAddImplicitObjectParameterType(S.Context, Method2, Args2);
Args2.insert(Args2.end(),
Proto2->arg_type_begin() + Skip2, Proto2->arg_type_end());
unsigned NumParams = std::min(Args1.size(), Args2.size());
for (unsigned I = 0; I != NumParams; ++I)
if (DeduceTemplateArgumentsDuringPartialOrdering(S,
TemplateParams,
Args2[I],
Args1[I],
Info,
Deduced,
QualifierComparisons))
// C++ [temp.func.order]p5:
// The presence of unused ellipsis and default arguments has no effect on
// the partial ordering of function templates.
if (Args1.size() > NumCallArguments)
Args1.resize(NumCallArguments);
if (Args2.size() > NumCallArguments)
Args2.resize(NumCallArguments);
if (DeduceTemplateArguments(S, TemplateParams, Args2.data(), Args2.size(),
Args1.data(), Args1.size(), Info, Deduced,
TDF_None, /*PartialOrdering=*/true,
QualifierComparisons))
return false;
break;
@ -2980,26 +2975,21 @@ static bool isAtLeastAsSpecializedAs(Sema &S,
case TPOC_Conversion:
// - In the context of a call to a conversion operator, the return types
// of the conversion function templates are used.
if (DeduceTemplateArgumentsDuringPartialOrdering(S,
TemplateParams,
Proto2->getResultType(),
Proto1->getResultType(),
Info,
Deduced,
QualifierComparisons))
if (DeduceTemplateArguments(S, TemplateParams, Proto2->getResultType(),
Proto1->getResultType(), Info, Deduced,
TDF_None, /*PartialOrdering=*/true,
QualifierComparisons))
return false;
break;
case TPOC_Other:
// - In other contexts (14.6.6.2) the function template’s function type
// is used.
if (DeduceTemplateArgumentsDuringPartialOrdering(S,
TemplateParams,
FD2->getType(),
FD1->getType(),
Info,
Deduced,
QualifierComparisons))
// FIXME: Don't we actually want to perform the adjustments on the parameter
// types?
if (DeduceTemplateArguments(S, TemplateParams, FD2->getType(),
FD1->getType(), Info, Deduced, TDF_None,
/*PartialOrdering=*/true, QualifierComparisons))
return false;
break;
}
@ -3026,7 +3016,9 @@ static bool isAtLeastAsSpecializedAs(Sema &S,
UsedParameters.resize(TemplateParams->size());
switch (TPOC) {
case TPOC_Call: {
unsigned NumParams = std::min(Proto1->getNumArgs(), Proto2->getNumArgs());
unsigned NumParams = std::min(NumCallArguments,
std::min(Proto1->getNumArgs(),
Proto2->getNumArgs()));
if (S.getLangOptions().CPlusPlus0x && IsNonStatic2 && !IsNonStatic1)
::MarkUsedTemplateParameters(S, Method2->getThisType(S.Context), false,
TemplateParams->getDepth(), UsedParameters);
@ -3070,16 +3062,22 @@ static bool isAtLeastAsSpecializedAs(Sema &S,
/// \param TPOC the context in which we are performing partial ordering of
/// function templates.
///
/// \param NumCallArguments The number of arguments in a call, used only
/// when \c TPOC is \c TPOC_Call.
///
/// \returns the more specialized function template. If neither
/// template is more specialized, returns NULL.
FunctionTemplateDecl *
Sema::getMoreSpecializedTemplate(FunctionTemplateDecl *FT1,
FunctionTemplateDecl *FT2,
SourceLocation Loc,
TemplatePartialOrderingContext TPOC) {
TemplatePartialOrderingContext TPOC,
unsigned NumCallArguments) {
llvm::SmallVector<DeductionQualifierComparison, 4> QualifierComparisons;
bool Better1 = isAtLeastAsSpecializedAs(*this, Loc, FT1, FT2, TPOC, 0);
bool Better1 = isAtLeastAsSpecializedAs(*this, Loc, FT1, FT2, TPOC,
NumCallArguments, 0);
bool Better2 = isAtLeastAsSpecializedAs(*this, Loc, FT2, FT1, TPOC,
NumCallArguments,
&QualifierComparisons);
if (Better1 != Better2) // We have a clear winner
@ -3156,6 +3154,9 @@ static bool isSameTemplate(TemplateDecl *T1, TemplateDecl *T2) {
/// \param TPOC the partial ordering context to use to compare the function
/// template specializations.
///
/// \param NumCallArguments The number of arguments in a call, used only
/// when \c TPOC is \c TPOC_Call.
///
/// \param Loc the location where the ambiguity or no-specializations
/// diagnostic should occur.
///
@ -3181,8 +3182,9 @@ static bool isSameTemplate(TemplateDecl *T1, TemplateDecl *T2) {
/// template argument deduction.
UnresolvedSetIterator
Sema::getMostSpecialized(UnresolvedSetIterator SpecBegin,
UnresolvedSetIterator SpecEnd,
UnresolvedSetIterator SpecEnd,
TemplatePartialOrderingContext TPOC,
unsigned NumCallArguments,
SourceLocation Loc,
const PartialDiagnostic &NoneDiag,
const PartialDiagnostic &AmbigDiag,
@ -3206,7 +3208,7 @@ Sema::getMostSpecialized(UnresolvedSetIterator SpecBegin,
= cast<FunctionDecl>(*I)->getPrimaryTemplate();
assert(Challenger && "Not a function template specialization?");
if (isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger,
Loc, TPOC),
Loc, TPOC, NumCallArguments),
Challenger)) {
Best = I;
BestTemplate = Challenger;
@ -3221,7 +3223,7 @@ Sema::getMostSpecialized(UnresolvedSetIterator SpecBegin,
= cast<FunctionDecl>(*I)->getPrimaryTemplate();
if (I != Best &&
!isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger,
Loc, TPOC),
Loc, TPOC, NumCallArguments),
BestTemplate)) {
Ambiguous = true;
break;
@ -3293,13 +3295,10 @@ Sema::getMoreSpecializedPartialSpecialization(
// Determine whether PS1 is at least as specialized as PS2
Deduced.resize(PS2->getTemplateParameters()->size());
bool Better1 = !DeduceTemplateArgumentsDuringPartialOrdering(*this,
PS2->getTemplateParameters(),
PT2,
PT1,
Info,
Deduced,
0);
bool Better1 = !::DeduceTemplateArguments(*this, PS2->getTemplateParameters(),
PT2, PT1, Info, Deduced, TDF_None,
/*PartialOrdering=*/true,
/*QualifierComparisons=*/0);
if (Better1) {
InstantiatingTemplate Inst(*this, PS2->getLocation(), PS2,
Deduced.data(), Deduced.size(), Info);
@ -3311,13 +3310,10 @@ Sema::getMoreSpecializedPartialSpecialization(
// Determine whether PS2 is at least as specialized as PS1
Deduced.clear();
Deduced.resize(PS1->getTemplateParameters()->size());
bool Better2 = !DeduceTemplateArgumentsDuringPartialOrdering(*this,
PS1->getTemplateParameters(),
PT1,
PT2,
Info,
Deduced,
0);
bool Better2 = !::DeduceTemplateArguments(*this, PS1->getTemplateParameters(),
PT1, PT2, Info, Deduced, TDF_None,
/*PartialOrdering=*/true,
/*QualifierComparisons=*/0);
if (Better2) {
InstantiatingTemplate Inst(*this, PS1->getLocation(), PS1,
Deduced.data(), Deduced.size(), Info);

6
clang/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.partial/p11.cpp
View File

@ -13,10 +13,10 @@ struct identity {
};
template <class T>
T* f2(int, typename identity<T>::type = 0); // expected-note{{candidate}}
T* f2(int, typename identity<T>::type = 0);
template <class T, class U>
T& f2(U, typename identity<T>::type = 0); // expected-note{{candidate}}
T& f2(U, typename identity<T>::type = 0);
void g2() {
f2<int>(1); // expected-error{{ambiguous}}
int* ip = f2<int>(1);
}