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;