When we're substituting into a function parameter pack and expect to
get a function parameter pack (but don't due to weird substitutions),
complain. Fixes the last bit of PR11848.
llvm-svn: 148960
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 30f0de3..cf77a7e 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -5100,7 +5100,8 @@
ParmVarDecl *SubstParmVarDecl(ParmVarDecl *D,
const MultiLevelTemplateArgumentList &TemplateArgs,
int indexAdjustment,
- llvm::Optional<unsigned> NumExpansions);
+ llvm::Optional<unsigned> NumExpansions,
+ bool ExpectParameterPack);
bool SubstParmTypes(SourceLocation Loc,
ParmVarDecl **Params, unsigned NumParams,
const MultiLevelTemplateArgumentList &TemplateArgs,
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index e183f1f..dde7826 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -778,7 +778,8 @@
FunctionProtoTypeLoc TL);
ParmVarDecl *TransformFunctionTypeParam(ParmVarDecl *OldParm,
int indexAdjustment,
- llvm::Optional<unsigned> NumExpansions);
+ llvm::Optional<unsigned> NumExpansions,
+ bool ExpectParameterPack);
/// \brief Transforms a template type parameter type by performing
/// substitution of the corresponding template type argument.
@@ -1194,9 +1195,10 @@
ParmVarDecl *
TemplateInstantiator::TransformFunctionTypeParam(ParmVarDecl *OldParm,
int indexAdjustment,
- llvm::Optional<unsigned> NumExpansions) {
+ llvm::Optional<unsigned> NumExpansions,
+ bool ExpectParameterPack) {
return SemaRef.SubstParmVarDecl(OldParm, TemplateArgs, indexAdjustment,
- NumExpansions);
+ NumExpansions, ExpectParameterPack);
}
QualType
@@ -1450,7 +1452,8 @@
ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
const MultiLevelTemplateArgumentList &TemplateArgs,
int indexAdjustment,
- llvm::Optional<unsigned> NumExpansions) {
+ llvm::Optional<unsigned> NumExpansions,
+ bool ExpectParameterPack) {
TypeSourceInfo *OldDI = OldParm->getTypeSourceInfo();
TypeSourceInfo *NewDI = 0;
@@ -1471,7 +1474,16 @@
// Therefore, make its type a pack expansion type.
NewDI = CheckPackExpansion(NewDI, ExpansionTL.getEllipsisLoc(),
NumExpansions);
- }
+ } else if (ExpectParameterPack) {
+ // We expected to get a parameter pack but didn't (because the type
+ // itself is not a pack expansion type), so complain. This can occur when
+ // the substitution goes through an alias template that "loses" the
+ // pack expansion.
+ Diag(OldParm->getLocation(),
+ diag::err_function_parameter_pack_without_parameter_packs)
+ << NewDI->getType();
+ return 0;
+ }
} else {
NewDI = SubstType(OldDI, TemplateArgs, OldParm->getLocation(),
OldParm->getDeclName());
@@ -1506,9 +1518,7 @@
NewParm->setUninstantiatedDefaultArg(Arg);
NewParm->setHasInheritedDefaultArg(OldParm->hasInheritedDefaultArg());
-
- // FIXME: When OldParm is a parameter pack and NewParm is not a parameter
- // pack, we actually have a set of instantiated locations. Maintain this set!
+
if (OldParm->isParameterPack() && !NewParm->isParameterPack()) {
// Add the new parameter to the instantiated parameter pack.
CurrentInstantiationScope->InstantiatedLocalPackArg(OldParm, NewParm);
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index c9d2cf6..023005c 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1601,7 +1601,8 @@
ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0,
- llvm::Optional<unsigned>());
+ llvm::Optional<unsigned>(),
+ /*ExpectParameterPack=*/false);
}
Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 2ddba47..f5fc3b7 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -530,7 +530,8 @@
/// scope index; can be negative
ParmVarDecl *TransformFunctionTypeParam(ParmVarDecl *OldParm,
int indexAdjustment,
- llvm::Optional<unsigned> NumExpansions);
+ llvm::Optional<unsigned> NumExpansions,
+ bool ExpectParameterPack);
QualType TransformReferenceType(TypeLocBuilder &TLB, ReferenceTypeLoc TL);
@@ -3814,12 +3815,14 @@
ParmVarDecl *
TreeTransform<Derived>::TransformFunctionTypeParam(ParmVarDecl *OldParm,
int indexAdjustment,
- llvm::Optional<unsigned> NumExpansions) {
+ llvm::Optional<unsigned> NumExpansions,
+ bool ExpectParameterPack) {
TypeSourceInfo *OldDI = OldParm->getTypeSourceInfo();
TypeSourceInfo *NewDI = 0;
if (NumExpansions && isa<PackExpansionType>(OldDI->getType())) {
// If we're substituting into a pack expansion type and we know the
+ // length we want to expand to, just substitute for the pattern.
TypeLoc OldTL = OldDI->getTypeLoc();
PackExpansionTypeLoc OldExpansionTL = cast<PackExpansionTypeLoc>(OldTL);
@@ -3916,7 +3919,8 @@
ParmVarDecl *NewParm
= getDerived().TransformFunctionTypeParam(OldParm,
indexAdjustment++,
- OrigNumExpansions);
+ OrigNumExpansions,
+ /*ExpectParameterPack=*/false);
if (!NewParm)
return true;
@@ -3932,7 +3936,8 @@
ParmVarDecl *NewParm
= getDerived().TransformFunctionTypeParam(OldParm,
indexAdjustment++,
- OrigNumExpansions);
+ OrigNumExpansions,
+ /*ExpectParameterPack=*/false);
if (!NewParm)
return true;
@@ -3956,11 +3961,13 @@
Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(getSema(), -1);
NewParm = getDerived().TransformFunctionTypeParam(OldParm,
indexAdjustment,
- NumExpansions);
+ NumExpansions,
+ /*ExpectParameterPack=*/true);
} else {
NewParm = getDerived().TransformFunctionTypeParam(OldParm,
indexAdjustment,
- llvm::Optional<unsigned>());
+ llvm::Optional<unsigned>(),
+ /*ExpectParameterPack=*/false);
}
if (!NewParm)
diff --git a/clang/test/SemaTemplate/alias-templates.cpp b/clang/test/SemaTemplate/alias-templates.cpp
index c0f9e21..75615ee 100644
--- a/clang/test/SemaTemplate/alias-templates.cpp
+++ b/clang/test/SemaTemplate/alias-templates.cpp
@@ -85,7 +85,7 @@
template<typename T>
struct Hidden1 {
template<typename ...Ts>
- Hidden1(typename T::template U<Ts> ...ts);
+ Hidden1(typename T::template U<Ts> ...ts); // expected-error{{type 'typename Hide::U<Ts>' (aka 'int') of function parameter pack does not contain any unexpanded parameter packs}}
};
template<typename T, typename ...Ts>
@@ -97,7 +97,6 @@
template<typename T> using U = int;
};
- // FIXME: This case crashes clang at the moment.
- //Hidden1<Hide> h1;
+ Hidden1<Hide> h1; // expected-note{{in instantiation of template class 'PR11848::Hidden1<PR11848::Hide>' requested here}}
Hidden2<Hide, double, char> h2(1, 2);
}