Lambdas are not necessarily locals. This resolves DR48250.

Differential Revision: https://reviews.llvm.org/D99134

(cherry picked from commit 0bff3a9)

Author: davidstone

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

@@ -6012,7 +6012,9 @@ NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
       (ParentDependsOnArgs && (ParentDC->isFunctionOrMethod() ||
                                isa<OMPDeclareReductionDecl>(ParentDC) ||
                                isa<OMPDeclareMapperDecl>(ParentDC))) ||
-      (isa<CXXRecordDecl>(D) && cast<CXXRecordDecl>(D)->isLambda())) {
+      (isa<CXXRecordDecl>(D) && cast<CXXRecordDecl>(D)->isLambda() &&
+       cast<CXXRecordDecl>(D)->getTemplateDepth() >
+           TemplateArgs.getNumRetainedOuterLevels())) {
     // D is a local of some kind. Look into the map of local
     // declarations to their instantiations.
     if (CurrentInstantiationScope) {

clang/test/SemaCXX/lambdas-implicit-explicit-template.cpp

@@ -39,3 +39,13 @@ void c2() {
   const auto lambda = [&](auto arg1) {};
   [&](auto arg2) { lambda.operator()(arg2); }(0);
 }
+
+auto d = [](auto) {};
+
+template <typename T>
+void d1(T x) { d.operator()(x); }
+
+void d2() { d1(0); }
+
+template <typename T> int e1 = [](auto){ return T(); }.operator()(T());
+int e2 = e1<int>;