Implement restriction that a partial specialization must actually specialize
something, for variable templates.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@191278 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index a7a6bb4..09dd28e 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -2273,6 +2273,69 @@
static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D);
+static bool isTemplateArgumentTemplateParameter(
+ const TemplateArgument &Arg, unsigned Depth, unsigned Index) {
+ switch (Arg.getKind()) {
+ case TemplateArgument::Null:
+ case TemplateArgument::NullPtr:
+ case TemplateArgument::Integral:
+ case TemplateArgument::Declaration:
+ case TemplateArgument::Pack:
+ case TemplateArgument::TemplateExpansion:
+ return false;
+
+ case TemplateArgument::Type: {
+ QualType Type = Arg.getAsType();
+ const TemplateTypeParmType *TPT =
+ Arg.getAsType()->getAs<TemplateTypeParmType>();
+ return TPT && !Type.hasQualifiers() &&
+ TPT->getDepth() == Depth && TPT->getIndex() == Index;
+ }
+
+ case TemplateArgument::Expression: {
+ DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr());
+ if (!DRE || !DRE->getDecl())
+ return false;
+ const NonTypeTemplateParmDecl *NTTP =
+ dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
+ return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index;
+ }
+
+ case TemplateArgument::Template:
+ const TemplateTemplateParmDecl *TTP =
+ dyn_cast_or_null<TemplateTemplateParmDecl>(
+ Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
+ return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index;
+ }
+ llvm_unreachable("unexpected kind of template argument");
+}
+
+static bool isSameAsPrimaryTemplate(TemplateParameterList *Params,
+ ArrayRef<TemplateArgument> Args) {
+ if (Params->size() != Args.size())
+ return false;
+
+ unsigned Depth = Params->getDepth();
+
+ for (unsigned I = 0, N = Args.size(); I != N; ++I) {
+ TemplateArgument Arg = Args[I];
+
+ // If the parameter is a pack expansion, the argument must be a pack
+ // whose only element is a pack expansion.
+ if (Params->getParam(I)->isParameterPack()) {
+ if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 ||
+ !Arg.pack_begin()->isPackExpansion())
+ return false;
+ Arg = Arg.pack_begin()->getPackExpansionPattern();
+ }
+
+ if (!isTemplateArgumentTemplateParameter(Arg, Depth, I))
+ return false;
+ }
+
+ return true;
+}
+
DeclResult Sema::ActOnVarTemplateSpecialization(
Scope *S, VarTemplateDecl *VarTemplate, Declarator &D, TypeSourceInfo *DI,
SourceLocation TemplateKWLoc, TemplateParameterList *TemplateParams,
@@ -2341,6 +2404,21 @@
<< VarTemplate->getDeclName();
IsPartialSpecialization = false;
}
+
+ if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
+ Converted)) {
+ // C++ [temp.class.spec]p9b3:
+ //
+ // -- The argument list of the specialization shall not be identical
+ // to the implicit argument list of the primary template.
+ Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
+ << /*variable template*/ 1
+ << /*is definition*/(SC != SC_Extern && !CurContext->isRecord())
+ << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
+ // FIXME: Recover from this by treating the declaration as a redeclaration
+ // of the primary template.
+ return true;
+ }
}
void *InsertPos = 0;
@@ -2402,7 +2480,8 @@
unsigned NumNonDeducible =
DeducibleParams.size() - DeducibleParams.count();
Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible)
- << (NumNonDeducible > 1) << SourceRange(TemplateNameLoc, RAngleLoc);
+ << /*variable template*/ 1 << (NumNonDeducible > 1)
+ << SourceRange(TemplateNameLoc, RAngleLoc);
for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
if (!DeducibleParams[I]) {
NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I));
@@ -5881,7 +5960,7 @@
// -- The argument list of the specialization shall not be identical
// to the implicit argument list of the primary template.
Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
- << (TUK == TUK_Definition)
+ << /*class template*/0 << (TUK == TUK_Definition)
<< FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS,
ClassTemplate->getIdentifier(),
@@ -5935,7 +6014,7 @@
if (!DeducibleParams.all()) {
unsigned NumNonDeducible = DeducibleParams.size()-DeducibleParams.count();
Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible)
- << (NumNonDeducible > 1)
+ << /*class template*/0 << (NumNonDeducible > 1)
<< SourceRange(TemplateNameLoc, RAngleLoc);
for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
if (!DeducibleParams[I]) {