Handle use of default member initializers before end of outermost class
Specifically, when we have this situation:
struct A {
template <typename T> struct B {
int m1 = sizeof(A);
};
B<int> m2;
};
We can't parse m1's initializer eagerly because we need A to be
complete. Therefore we wait until the end of A's class scope to parse
it. However, we can trigger instantiation of B before the end of A,
which will attempt to instantiate the field decls eagerly, and it would
build a bad field decl instantiation that said it had an initializer but
actually lacked one.
Fixed by deferring instantiation of default member initializers until
they are needed during constructor analysis. This addresses a long
standing FIXME in the code.
Fixes PR19195.
Reviewed By: rsmith
Differential Revision: http://reviews.llvm.org/D5690
llvm-svn: 222192
diff --git a/clang/test/SemaCXX/member-init.cpp b/clang/test/SemaCXX/member-init.cpp
index d8a00b3..5acb480 100644
--- a/clang/test/SemaCXX/member-init.cpp
+++ b/clang/test/SemaCXX/member-init.cpp
@@ -14,7 +14,10 @@
bool b();
int k;
struct Recurse {
- int &n = b() ? Recurse().n : k; // expected-error {{defaulted default constructor of 'Recurse' cannot be used by non-static data member initializer which appears before end of class definition}}
+ int &n = // expected-error {{cannot use defaulted default constructor of 'Recurse' within the class outside of member functions because 'n' has an initializer}}
+ b() ?
+ Recurse().n : // expected-note {{implicit default constructor for 'Recurse' first required here}}
+ k;
};
struct UnknownBound {
@@ -110,3 +113,75 @@
struct Y { int b = f(); };
}
+
+namespace template_valid {
+// Valid, we shouldn't build a CXXDefaultInitExpr until A's ctor definition.
+struct A {
+ A();
+ template <typename T>
+ struct B { int m1 = sizeof(A) + sizeof(T); };
+ B<int> m2;
+};
+A::A() {}
+}
+
+namespace template_default_ctor {
+struct A {
+ template <typename T>
+ struct B {
+ int m1 = 0; // expected-error {{cannot use defaulted default constructor of 'B' within 'A' outside of member functions because 'm1' has an initializer}}
+ };
+ // expected-note@+1 {{implicit default constructor for 'template_default_ctor::A::B<int>' first required here}}
+ enum { NOE = noexcept(B<int>()) };
+};
+}
+
+namespace default_ctor {
+struct A {
+ struct B {
+ int m1 = 0; // expected-error {{cannot use defaulted default constructor of 'B' within 'A' outside of member functions because 'm1' has an initializer}}
+ };
+ // expected-note@+1 {{implicit default constructor for 'default_ctor::A::B' first required here}}
+ enum { NOE = noexcept(B()) };
+};
+}
+
+namespace member_template {
+struct A {
+ template <typename T>
+ struct B {
+ struct C {
+ int m1 = 0; // expected-error {{cannot use defaulted default constructor of 'C' within 'A' outside of member functions because 'm1' has an initializer}}
+ };
+ template <typename U>
+ struct D {
+ int m1 = 0; // expected-error {{cannot use defaulted default constructor of 'D' within 'A' outside of member functions because 'm1' has an initializer}}
+ };
+ };
+ enum {
+ // expected-note@+1 {{implicit default constructor for 'member_template::A::B<int>::C' first required here}}
+ NOE1 = noexcept(B<int>::C()),
+ // expected-note@+1 {{implicit default constructor for 'member_template::A::B<int>::D<int>' first required here}}
+ NOE2 = noexcept(B<int>::D<int>())
+ };
+};
+}
+
+namespace explicit_instantiation {
+template<typename T> struct X {
+ X(); // expected-note {{in instantiation of default member initializer 'explicit_instantiation::X<float>::n' requested here}}
+ int n = T::error; // expected-error {{type 'float' cannot be used prior to '::' because it has no members}}
+};
+template struct X<int>; // ok
+template<typename T> X<T>::X() {}
+template struct X<float>; // expected-note {{in instantiation of member function 'explicit_instantiation::X<float>::X' requested here}}
+}
+
+namespace local_class {
+template<typename T> void f() {
+ struct X { // expected-note {{in instantiation of default member initializer 'local_class::f()::X::n' requested here}}
+ int n = T::error; // expected-error {{type 'int' cannot be used prior to '::' because it has no members}}
+ };
+}
+void g() { f<int>(); } // expected-note {{in instantiation of function template specialization 'local_class::f<int>' requested here}}
+}