Mark 'auto' as dependent when instantiating the type of a non-type template
parameter. Fixes failed deduction for 'auto' non-type template parameters
nested within templates.
llvm-svn: 290660
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 996a8ba..55421a3 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -729,8 +729,22 @@
///
/// \returns the (possibly-promoted) parameter type if valid;
/// otherwise, produces a diagnostic and returns a NULL type.
-QualType
-Sema::CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc) {
+QualType Sema::CheckNonTypeTemplateParameterType(TypeSourceInfo *&TSI,
+ SourceLocation Loc) {
+ if (TSI->getType()->isUndeducedType()) {
+ // C++1z [temp.dep.expr]p3:
+ // An id-expression is type-dependent if it contains
+ // - an identifier associated by name lookup with a non-type
+ // template-parameter declared with a type that contains a
+ // placeholder type (7.1.7.4),
+ TSI = SubstAutoTypeSourceInfo(TSI, Context.DependentTy);
+ }
+
+ return CheckNonTypeTemplateParameterType(TSI->getType(), Loc);
+}
+
+QualType Sema::CheckNonTypeTemplateParameterType(QualType T,
+ SourceLocation Loc) {
// We don't allow variably-modified types as the type of non-type template
// parameters.
if (T->isVariablyModifiedType()) {
@@ -759,10 +773,6 @@
T->isDependentType() ||
// Allow use of auto in template parameter declarations.
T->isUndeducedType()) {
- if (T->isUndeducedType()) {
- Diag(Loc, diag::warn_cxx14_compat_template_nontype_parm_auto_type)
- << QualType(T->getContainedAutoType(), 0);
- }
// C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter
// are ignored when determining its type.
return T.getUnqualifiedType();
@@ -788,13 +798,18 @@
SourceLocation EqualLoc,
Expr *Default) {
TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
- QualType T = TInfo->getType();
+
+ if (TInfo->getType()->isUndeducedType()) {
+ Diag(D.getIdentifierLoc(),
+ diag::warn_cxx14_compat_template_nontype_parm_auto_type)
+ << QualType(TInfo->getType()->getContainedAutoType(), 0);
+ }
assert(S->isTemplateParamScope() &&
"Non-type template parameter not in template parameter scope!");
bool Invalid = false;
- T = CheckNonTypeTemplateParameterType(T, D.getIdentifierLoc());
+ QualType T = CheckNonTypeTemplateParameterType(TInfo, D.getIdentifierLoc());
if (T.isNull()) {
T = Context.IntTy; // Recover with an 'int' type.
Invalid = true;
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 8e671ad..7328dcb 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2085,18 +2085,18 @@
ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
- TypeSourceInfo *NewDI =SemaRef.SubstType(D->getExpansionTypeSourceInfo(I),
- TemplateArgs,
- D->getLocation(),
- D->getDeclName());
+ TypeSourceInfo *NewDI =
+ SemaRef.SubstType(D->getExpansionTypeSourceInfo(I), TemplateArgs,
+ D->getLocation(), D->getDeclName());
if (!NewDI)
return nullptr;
- ExpandedParameterPackTypesAsWritten.push_back(NewDI);
- QualType NewT =SemaRef.CheckNonTypeTemplateParameterType(NewDI->getType(),
- D->getLocation());
+ QualType NewT =
+ SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
if (NewT.isNull())
return nullptr;
+
+ ExpandedParameterPackTypesAsWritten.push_back(NewDI);
ExpandedParameterPackTypes.push_back(NewT);
}
@@ -2136,12 +2136,12 @@
if (!NewDI)
return nullptr;
- ExpandedParameterPackTypesAsWritten.push_back(NewDI);
- QualType NewT = SemaRef.CheckNonTypeTemplateParameterType(
- NewDI->getType(),
- D->getLocation());
+ QualType NewT =
+ SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
if (NewT.isNull())
return nullptr;
+
+ ExpandedParameterPackTypesAsWritten.push_back(NewDI);
ExpandedParameterPackTypes.push_back(NewT);
}
@@ -2161,6 +2161,7 @@
if (!NewPattern)
return nullptr;
+ SemaRef.CheckNonTypeTemplateParameterType(NewPattern, D->getLocation());
DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
NumExpansions);
if (!DI)
@@ -2176,8 +2177,7 @@
return nullptr;
// Check that this type is acceptable for a non-type template parameter.
- T = SemaRef.CheckNonTypeTemplateParameterType(DI->getType(),
- D->getLocation());
+ T = SemaRef.CheckNonTypeTemplateParameterType(DI, D->getLocation());
if (T.isNull()) {
T = SemaRef.Context.IntTy;
Invalid = true;
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index aa38879..ae9a3ee 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -1534,14 +1534,7 @@
// template type parameter.
Result = QualType(CorrespondingTemplateParam->getTypeForDecl(), 0);
} else {
- // If auto appears in the declaration of a template parameter, treat
- // the parameter as type-dependent.
- bool IsDependent =
- S.getLangOpts().CPlusPlus1z &&
- declarator.getContext() == Declarator::TemplateParamContext;
- Result = Context.getAutoType(QualType(),
- AutoTypeKeyword::Auto,
- IsDependent);
+ Result = Context.getAutoType(QualType(), AutoTypeKeyword::Auto, false);
}
break;