// Introduce a new scope where local variable instantiations will be
// recorded, unless we're actually a member function within a local
// class, in which case we need to merge our results with the parent
- // scope (of the enclosing function).
+ // scope (of the enclosing function). The exception is instantiating
+ // a function template specialization, since the template to be
+ // instantiated already has references to locals properly substituted.
bool MergeWithParentScope = false;
if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
- MergeWithParentScope = Rec->isLocalClass();
+ MergeWithParentScope =
+ Rec->isLocalClass() && !Function->isFunctionTemplateSpecialization();
LocalInstantiationScope Scope(*this, MergeWithParentScope);
--- /dev/null
+// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify %s
+
+// expected-no-diagnostics
+
+// Check recursive instantiation of lambda does not cause assertion.
+// lambda function `f` in `fun1` is instantiated twice: first
+// as f(f, Number<1>), then as f(f, Number<0>). The
+// LocalInstantiationScopes of these two instantiations both contain
+// `f` and `i`. However, since they are not merged, clang should not
+// assert for that.
+
+template <unsigned v>
+struct Number
+{
+ static constexpr unsigned value = v;
+};
+
+template <unsigned IBegin = 0,
+ unsigned IEnd = 1>
+constexpr auto fun1(Number<IBegin> = Number<0>{}, Number<IEnd> = Number<1>{})
+{
+ constexpr unsigned a = 0;
+ auto f = [&](auto fs, auto i) {
+ if constexpr(i.value > 0)
+ {
+ (void)a;
+ return fs(fs, Number<IBegin>{});
+ }
+ (void)a;
+ };
+
+ return f(f, Number<IEnd>{});
+}
+
+
+void fun2() {
+ fun1();
+}