c++: Add carries_dependency further test coverage [PR110345]

This patch adds additional test coverage for the carries_dependency
attribute (unlike other attributes, the attribute actually isn't implemented
for real, so we warn even in the cases of valid uses because we ignore those
as well).

2024-12-18  Jakub Jelinek  <jakub@redhat.com>

	PR c++/110345
	* g++.dg/cpp0x/attr-carries_dependency2.C: New test.

diff --git a/gcc/testsuite/g++.dg/cpp0x/attr-carries_dependency2.C b/gcc/testsuite/g++.dg/cpp0x/attr-carries_dependency2.C
new file mode 100644 (file)
index 0000000..b3fb518
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/attr-carries_dependency2.C
@@ -0,0 +1,152 @@
+// C++ 26 P2552R3 - On the ignorability of standard attributes
+// { dg-do compile { target c++11 } }
+
+int arr[2];
+struct S { int a, b; };
+S arr2[2];
+
+void
+xyzzy (int *a [[carries_dependency]],                  // { dg-warning "'carries_dependency' attribute ignored" }
+       int *b [[carries_dependency (1)]])              // { dg-error "'carries_dependency' attribute does not take any arguments" }
+{                                                      // { dg-error "expected ',' or '...' before 'b'" "" { target *-*-* } .-1 }
+}
+
+void
+foo (int n)
+{
+  [[carries_dependency]] int x1;                       // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+
+  auto a = [] [[carries_dependency]] () {};            // { dg-warning "'carries_dependency' attribute ignored" }
+  auto b = [] constexpr [[carries_dependency]] {};     // { dg-warning "'carries_dependency' attribute does not apply to types" }
+                                                       // { dg-error "parameter declaration before lambda declaration specifiers only optional with" "" { target c++20_down } .-1 }
+                                                       // { dg-error "'constexpr' lambda only available with" "" { target c++14_down } .-2 }
+  auto c = [] noexcept [[carries_dependency]] {};      // { dg-warning "'carries_dependency' attribute does not apply to types" }
+                                                       // { dg-error "parameter declaration before lambda exception specification only optional with" "" { target c++20_down } .-1 }
+  auto d = [] () [[carries_dependency]] {};            // { dg-warning "'carries_dependency' attribute does not apply to types" }
+  auto e = new int [n] [[carries_dependency]];         // { dg-warning "attributes ignored on outermost array type in new expression" }
+  auto e2 = new int [n] [[carries_dependency]] [42];   // { dg-warning "attributes ignored on outermost array type in new expression" }
+  auto f = new int [n][42] [[carries_dependency]];     // { dg-warning "'carries_dependency' attribute does not apply to types" }
+  [[carries_dependency]];                              // { dg-warning "attributes at the beginning of statement are ignored" }
+  [[carries_dependency]] {}                            // { dg-warning "attributes at the beginning of statement are ignored" }
+  [[carries_dependency]] if (true) {}                  // { dg-warning "attributes at the beginning of statement are ignored" }
+  [[carries_dependency]] while (false) {}              // { dg-warning "attributes at the beginning of statement are ignored" }
+  [[carries_dependency]] goto lab;                     // { dg-warning "attributes at the beginning of statement are ignored" }
+  [[carries_dependency]] lab:;                         // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+  [[carries_dependency]] try {} catch (int) {}         // { dg-warning "attributes at the beginning of statement are ignored" }
+  if ([[carries_dependency]] int x = 0) {}             // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+  switch (n)
+    {
+    [[carries_dependency]] case 1:                     // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+    [[carries_dependency]] break;                      // { dg-warning "attributes at the beginning of statement are ignored" }
+    [[carries_dependency]] default:                    // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+        break;
+    }
+  for ([[carries_dependency]] auto a : arr) {}         // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+  for ([[carries_dependency]] auto [a, b] : arr2) {}   // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+                                                       // { dg-error "structured bindings only available with" "" { target c++14_down } .-1 }
+  [[carries_dependency]] asm ("");                     // { dg-warning "attributes ignored on 'asm' declaration" }
+  try {} catch ([[carries_dependency]] int x) {}       // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+  try {} catch ([[carries_dependency]] int) {}         // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+  try {} catch (int [[carries_dependency]] x) {}       // { dg-warning "attribute ignored" }
+  try {} catch (int [[carries_dependency]]) {}         // { dg-warning "attribute ignored" }
+  try {} catch (int x [[carries_dependency]]) {}       // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+}
+
+[[carries_dependency]] int bar ();                     // { dg-warning "'carries_dependency' attribute ignored" }
+using foobar [[carries_dependency]] = int;             // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+[[carries_dependency]] int a;                          // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+[[carries_dependency]] auto [b, c] = arr;              // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+                                                       // { dg-error "structured bindings only available with" "" { target c++14_down } .-1 }
+[[carries_dependency]];                                        // { dg-warning "attribute ignored" }
+inline [[carries_dependency]] void baz () {}           // { dg-warning "attribute ignored" }
+                                                       // { dg-error "standard attributes in middle of decl-specifiers" "" { target *-*-* } .-1 }
+constexpr [[carries_dependency]] int qux () { return 0; }      // { dg-warning "attribute ignored" }
+                                                       // { dg-error "standard attributes in middle of decl-specifiers" "" { target *-*-* } .-1 }
+int [[carries_dependency]] d;                          // { dg-warning "attribute ignored" }
+int const [[carries_dependency]] e = 1;                        // { dg-warning "attribute ignored" }
+struct A {} [[carries_dependency]];                    // { dg-warning "attribute ignored in declaration of 'struct A'" }
+struct A [[carries_dependency]];                       // { dg-warning "attribute ignored" }
+struct A [[carries_dependency]] a1;                    // { dg-warning "attribute ignored" }
+A [[carries_dependency]] a2;                           // { dg-warning "attribute ignored" }
+enum B { B0 } [[carries_dependency]];                  // { dg-warning "attribute ignored in declaration of 'enum B'" }
+enum B [[carries_dependency]];                         // { dg-warning "attribute ignored" }
+enum B [[carries_dependency]] b1;                      // { dg-warning "attribute ignored" }
+B [[carries_dependency]] b2;                           // { dg-warning "attribute ignored" }
+struct [[carries_dependency]] C {};                    // { dg-warning "'carries_dependency' attribute does not apply to types" }
+int f [[carries_dependency]];                          // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+int g[2] [[carries_dependency]];                       // { dg-warning "'carries_dependency' attribute does not apply to types" }
+int g2 [[carries_dependency]] [2];                     // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+int corge () [[carries_dependency]];                   // { dg-warning "'carries_dependency' attribute does not apply to types" }
+int *[[carries_dependency]] h;                         // { dg-warning "'carries_dependency' attribute does not apply to types" }
+int & [[carries_dependency]] i = f;                    // { dg-warning "'carries_dependency' attribute does not apply to types" }
+int && [[carries_dependency]] j = 0;                   // { dg-warning "'carries_dependency' attribute does not apply to types" }
+int S::* [[carries_dependency]] k;                     // { dg-warning "'carries_dependency' attribute does not apply to types" }
+auto l = sizeof (int [2] [[carries_dependency]]);      // { dg-warning "'carries_dependency' attribute does not apply to types" }
+int freddy ([[carries_dependency]] int a,              // { dg-warning "'carries_dependency' attribute ignored" }
+           [[carries_dependency]] int,                 // { dg-warning "'carries_dependency' attribute ignored" }
+           [[carries_dependency]] int c = 0,           // { dg-warning "'carries_dependency' attribute ignored" }
+           [[carries_dependency]] int = 0);            // { dg-warning "'carries_dependency' attribute ignored" }
+void
+corge ([[carries_dependency]] int a,                   // { dg-warning "'carries_dependency' attribute ignored" }
+       [[carries_dependency]] int,                     // { dg-warning "'carries_dependency' attribute ignored" }
+       [[carries_dependency]] int c = 0,               // { dg-warning "'carries_dependency' attribute ignored" }
+       [[carries_dependency]] int = 0)                 // { dg-warning "'carries_dependency' attribute ignored" }
+{
+}
+[[carries_dependency]] void
+garply ()                                              // { dg-warning "'carries_dependency' attribute ignored" }
+{
+}
+int grault (int [[carries_dependency]] a,              // { dg-warning "attribute ignored" }
+           int [[carries_dependency]],                 // { dg-warning "attribute ignored" }
+           int [[carries_dependency]] c = 0,           // { dg-warning "attribute ignored" }
+           int [[carries_dependency]] = 0);            // { dg-warning "attribute ignored" }
+void
+waldo (int [[carries_dependency]] a,                   // { dg-warning "attribute ignored" }
+       int [[carries_dependency]],                     // { dg-warning "attribute ignored" }
+       int [[carries_dependency]] c = 0,               // { dg-warning "attribute ignored" }
+       int [[carries_dependency]] = 0)                 // { dg-warning "attribute ignored" }
+{
+}
+int plugh (int a [[carries_dependency]],               // { dg-warning "'carries_dependency' attribute ignored" }
+           int b [[carries_dependency]] = 0);          // { dg-warning "'carries_dependency' attribute ignored" }
+void
+thud (int a [[carries_dependency]],                    // { dg-warning "'carries_dependency' attribute ignored" }
+      int b [[carries_dependency]] = 0)                        // { dg-warning "'carries_dependency' attribute ignored" }
+{
+}
+enum [[carries_dependency]] D { D0 };                  // { dg-warning "'carries_dependency' attribute does not apply to types" }
+enum class [[carries_dependency]] E { E0 };            // { dg-warning "'carries_dependency' attribute does not apply to types" }
+enum F {};
+enum [[carries_dependency]] F;                         // { dg-warning "'carries_dependency' attribute does not apply to types" }
+enum G {
+  G0 [[carries_dependency]],                           // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+  G1 [[carries_dependency]] = 2                                // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+};
+namespace [[carries_dependency]] H { using H0 = int; } // { dg-warning "'carries_dependency' attribute directive ignored" } */
+namespace [[carries_dependency]] {}                    // { dg-warning "'carries_dependency' attribute directive ignored" }
+[[carries_dependency]] using namespace H;              // { dg-warning "'carries_dependency' attribute directive ignored" }
+struct [[carries_dependency]] I                                // { dg-warning "'carries_dependency' attribute does not apply to types" }
+{
+  [[carries_dependency]];                              // { dg-error "declaration does not declare anything" }
+  [[carries_dependency]] int i;                                // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+  [[carries_dependency]] int foo ();                   // { dg-warning "'carries_dependency' attribute ignored" }
+  [[carries_dependency]] int bar () { return 1; }      // { dg-warning "'carries_dependency' attribute ignored" }
+  [[carries_dependency]] int : 0;                      // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+  [[carries_dependency]] int i2 : 5;                   // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+  [[carries_dependency]] static int i3;                        // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+  static int i4;
+};
+[[carries_dependency]] int I::i4 = 0;                  // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+struct J : [[carries_dependency]] C {};                        // { dg-warning "attributes on base specifiers are ignored" }
+#if __cpp_concepts >= 201907L
+template <typename T>
+concept K [[carries_dependency]] = requires { true; }; // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" "" { target c++20 } }
+#endif
+typedef int L [[carries_dependency]];                  // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }
+template <typename T>
+struct M {};
+template <>
+struct [[carries_dependency]] M<int> { int m; };       // { dg-warning "'carries_dependency' attribute does not apply to types" }
+typedef int N[2] [[carries_dependency]];               // { dg-warning "'carries_dependency' attribute does not apply to types" }
+typedef int O [[carries_dependency]] [2];              // { dg-warning "'carries_dependency' attribute can only be applied to functions or parameters" }