Updated test cases and annoted what should be worked on

Author: to268

clang/docs/ReleaseNotes.rst

@@ -348,7 +348,7 @@ C23 Feature Support
   but C23 added them to ``<float.h>`` in
   `WG14 N2848 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2848.pdf>`_.
 
-- Clang now diagnoses `N3006 Underspecified object declarations
+- Clang now diagnoses `N3006 Underspecified object declarations`
   <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3006.htm>`_.
 
 Non-comprehensive list of changes in this release

clang/test/C/C23/n3006.c

@@ -25,32 +25,42 @@ auto normal_enum_bar = (enum E1){ BAR };
 auto underspecified_enum = (enum E2 { BAZ, QUX }){ BAZ };       // expected-error {{'enum E2' is defined as an underspecified object initializer}}
 auto underspecified_enum_redef = (enum E1 { ONE, TWO }){ ONE }; // expected-error {{redefinition of 'E1'}}
 auto underspecified_empty_enum = (enum E3 {  }){ };             // expected-error {{'enum E3' is defined as an underspecified object initializer}} \
-                                                                   expected-error {{use of empty enum}}
-
-// Constexpr tests
-constexpr auto ce_struct = (struct S1){ 1, 2 };
-constexpr auto ce_union = (union U1){ .a = 12 };
-constexpr auto ce_enum = (enum E1){ FOO };
+                                                                     expected-error {{use of empty enum}}
+void constexpr_test() {
+  constexpr auto ce_struct = (struct S1){ 1, 2 };
+  constexpr auto ce_union = (union U1){ .a = 12 };
+  constexpr auto ce_enum = (enum E1){ FOO };
+}
 
-int func() {
-  struct S { int x, y; };
-  constexpr int i = (struct T { int a, b; }){0, 1}.a;
+void trivial_test() {
+  constexpr int i = i;  // expected-error {{constexpr variable 'i' must be initialized by a constant expression}} \
+                           expected-note {{read of object outside its lifetime is not allowed in a constant expression}}
+  auto j = j;           // expected-error {{variable 'j' declared with deduced type 'auto' cannot appear in its own initializer}}
+}
 
-  struct T t = { 1, 2 };
+void double_definition_test() {
+  const struct S { int x; } s;  // expected-note {{previous definition is here}}
+  constexpr struct S s = {0};   // expected-error {{redefinition of 's'}}
 }
 
-void func2() {
-  int x = (struct Foo { int x; }){ 0 }.x;
+void declaring_an_underspecified_defied_object_test() {
+  struct S { int x, y; };
+  constexpr int i = (struct T { int a, b; }){0, 1}.a;  // expected-error {{'struct T' is defined as an underspecified object initializer}} \
+                                                          FIXME: `constexpr variable 'i' must be initialized by a constant expression` shoud appear
+
+  struct T t = { 1, 2 };                         // TODO: Should this be diagnosed as an invalid declaration?
 }
 
-void func3() {
-  constexpr int x = (struct Foo { int x; }){ 0 }.x;
+void constexpr_complience_test() {
+  int x = (struct Foo { int x; }){ 0 }.x;           // expected-error {{'struct Foo' is defined as an underspecified object initializer}}
+  constexpr int y = (struct Bar { int x; }){ 0 }.x; // expected-error {{'struct Bar' is defined as an underspecified object initializer}}
 }
 
-void test() {
-    constexpr typeof(struct s *) x = 0; // declares `s` which is not an ordinary identifier
-    constexpr struct S { int a, b; } y = { 0 }; // declares `S`, `a`, and `b`, none of which are ordinary identifiers
-    constexpr int a = 0, b = 0; // declares `a` and `b` as ordinary identifiers
-    auto c = (struct T { int x, y; }){0, 0}; // declares `T`, `x`, and `y`, none of which are ordinary identifiers
-    constexpr int (*fp)(struct X { int x; } val) = 0; // declares `X` and `x` which are not ordinary identifiers
+void special_test() {
+  constexpr typeof(struct s *) x = 0;               // FIXME: declares `s` which is not an ordinary identifier
+  constexpr struct S { int a, b; } y = { 0 };    // FIXME: declares `S`, `a`, and `b`, none of which are ordinary identifiers
+  constexpr int a = 0, b = 0;
+  auto c = (struct T { int x, y; }){0, 0};          // expected-error {{'struct T' is defined as an underspecified object initializer}}
+  constexpr int (*fp)(struct X { int x; } val) = 0; // expected-warning {{declaration of 'struct X' will not be visible outside of this function}} \
+                                                       FIXME: declares `X` and `x` which are not ordinary identifiers
 }