[Sema] Ensure an auto non-type template parameter is dependent
The dependent auto was getting stripped away while rebuilding the template
parameter type, so substitute it in.
rdar://41852459
Differential revision: https://reviews.llvm.org/D50088
llvm-svn: 339198
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index fa002de..f31f0d4 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -974,7 +974,7 @@
QualType Sema::CheckNonTypeTemplateParameterType(TypeSourceInfo *&TSI,
SourceLocation Loc) {
if (TSI->getType()->isUndeducedType()) {
- // C++1z [temp.dep.expr]p3:
+ // C++17 [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
@@ -9866,6 +9866,15 @@
if (!NewTSI)
return true;
+ if (NewTSI->getType()->isUndeducedType()) {
+ // C++17 [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),
+ NewTSI = SubstAutoTypeSourceInfo(NewTSI, Context.DependentTy);
+ }
+
if (NewTSI != NTTP->getTypeSourceInfo()) {
NTTP->setTypeSourceInfo(NewTSI);
NTTP->setType(NewTSI->getType());