Perform the function-to-pointer adjustment during template argument
deduction where the parameter is a function reference, function
pointer, or member function pointer and the argument is an overloaded
function. Fixes <rdar://problem/8360106>, a template argument
deduction issue found by Boost.Filesystem.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@112523 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index 87d9feb..5c77ed6 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -1542,12 +1542,20 @@
/// undeduced context
static QualType
ResolveOverloadForDeduction(Sema &S, TemplateParameterList *TemplateParams,
- Expr *Arg, QualType ParamType) {
+ Expr *Arg, QualType ParamType,
+ bool ParamWasReference) {
OverloadExpr::FindResult R = OverloadExpr::find(Arg);
OverloadExpr *Ovl = R.Expression;
+ // C++0x [temp.deduct.call]p4
+ unsigned TDF = 0;
+ if (ParamWasReference)
+ TDF |= TDF_ParamWithReferenceType;
+ if (R.IsAddressOfOperand)
+ TDF |= TDF_IgnoreQualifiers;
+
// If there were explicit template arguments, we can only find
// something via C++ [temp.arg.explicit]p3, i.e. if the arguments
// unambiguously name a full specialization.
@@ -1583,6 +1591,11 @@
QualType ArgType = GetTypeOfFunction(S.Context, R, Fn);
if (ArgType.isNull()) continue;
+ // Function-to-pointer conversion.
+ if (!ParamWasReference && ParamType->isPointerType() &&
+ ArgType->isFunctionType())
+ ArgType = S.Context.getPointerType(ArgType);
+
// - If the argument is an overload set (not containing function
// templates), trial argument deduction is attempted using each
// of the members of the set. If deduction succeeds for only one
@@ -1598,8 +1611,6 @@
llvm::SmallVector<DeducedTemplateArgument, 8>
Deduced(TemplateParams->size());
TemplateDeductionInfo Info(S.Context, Ovl->getNameLoc());
- unsigned TDF = 0;
-
Sema::TemplateDeductionResult Result
= DeduceTemplateArguments(S, TemplateParams,
ParamType, ArgType,
@@ -1694,20 +1705,40 @@
QualType ParamType = ParamTypes[I];
QualType ArgType = Args[I]->getType();
+ // C++0x [temp.deduct.call]p3:
+ // If P is a cv-qualified type, the top level cv-qualifiers of P’s type
+ // are ignored for type deduction.
+ if (ParamType.getCVRQualifiers())
+ ParamType = ParamType.getLocalUnqualifiedType();
+ const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>();
+ if (ParamRefType) {
+ // [...] If P is a reference type, the type referred to by P is used
+ // for type deduction.
+ ParamType = ParamRefType->getPointeeType();
+ }
+
// Overload sets usually make this parameter an undeduced
// context, but there are sometimes special circumstances.
if (ArgType == Context.OverloadTy) {
ArgType = ResolveOverloadForDeduction(*this, TemplateParams,
- Args[I], ParamType);
+ Args[I], ParamType,
+ ParamRefType != 0);
if (ArgType.isNull())
continue;
}
- // C++ [temp.deduct.call]p2:
- // If P is not a reference type:
- QualType CanonParamType = Context.getCanonicalType(ParamType);
- bool ParamWasReference = isa<ReferenceType>(CanonParamType);
- if (!ParamWasReference) {
+ if (ParamRefType) {
+ // C++0x [temp.deduct.call]p3:
+ // [...] If P is of the form T&&, where T is a template parameter, and
+ // the argument is an lvalue, the type A& is used in place of A for
+ // type deduction.
+ if (ParamRefType->isRValueReferenceType() &&
+ ParamRefType->getAs<TemplateTypeParmType>() &&
+ Args[I]->isLvalue(Context) == Expr::LV_Valid)
+ ArgType = Context.getLValueReferenceType(ArgType);
+ } else {
+ // C++ [temp.deduct.call]p2:
+ // If P is not a reference type:
// - If A is an array type, the pointer type produced by the
// array-to-pointer standard conversion (4.2) is used in place of
// A for type deduction; otherwise,
@@ -1722,30 +1753,11 @@
// - If A is a cv-qualified type, the top level cv-qualifiers of A’s
// type are ignored for type deduction.
QualType CanonArgType = Context.getCanonicalType(ArgType);
- if (CanonArgType.getLocalCVRQualifiers())
- ArgType = CanonArgType.getLocalUnqualifiedType();
+ if (ArgType.getCVRQualifiers())
+ ArgType = ArgType.getUnqualifiedType();
}
}
- // C++0x [temp.deduct.call]p3:
- // If P is a cv-qualified type, the top level cv-qualifiers of P’s type
- // are ignored for type deduction.
- if (CanonParamType.getLocalCVRQualifiers())
- ParamType = CanonParamType.getLocalUnqualifiedType();
- if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) {
- // [...] If P is a reference type, the type referred to by P is used
- // for type deduction.
- ParamType = ParamRefType->getPointeeType();
-
- // [...] If P is of the form T&&, where T is a template parameter, and
- // the argument is an lvalue, the type A& is used in place of A for
- // type deduction.
- if (isa<RValueReferenceType>(ParamRefType) &&
- ParamRefType->getAs<TemplateTypeParmType>() &&
- Args[I]->isLvalue(Context) == Expr::LV_Valid)
- ArgType = Context.getLValueReferenceType(ArgType);
- }
-
// C++0x [temp.deduct.call]p4:
// In general, the deduction process attempts to find template argument
// values that will make the deduced A identical to A (after the type A
@@ -1755,7 +1767,7 @@
// - 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 (ParamWasReference)
+ if (ParamRefType)
TDF |= TDF_ParamWithReferenceType;
// - The transformed A can be another pointer or pointer to member
// type that can be converted to the deduced A via a qualification
diff --git a/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p6.cpp b/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p6.cpp
index 1b240cc..16b5cd2 100644
--- a/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p6.cpp
+++ b/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p6.cpp
@@ -93,3 +93,21 @@
invoke(&temp2<int, int>); // expected-error {{no matching function for call to 'invoke'}}
}
}
+
+namespace rdar8360106 {
+ template<typename R, typename T> void f0(R (*)(T), T);
+ template<typename R, typename T> void f1(R (&)(T) , T); // expected-note{{candidate template ignored: couldn't infer template argument 'R'}}
+ template<typename R, typename T> void f2(R (* const&)(T), T); // expected-note{{candidate template ignored: couldn't infer template argument 'R'}}
+
+ int g(int);
+ int g(int, int);
+
+ void h() {
+ f0(g, 1);
+ f0(&g, 1);
+ f1(g, 1);
+ f1(&g, 1); // expected-error{{no matching function for call to 'f1'}}
+ f2(g, 1); // expected-error{{no matching function for call to 'f2'}}
+ f2(&g, 1);
+ }
+}