On 9/5/24 3:19 AM, Jakub Jelinek wrote:
Hi!
Similarly for fallthrough attribute. Had to add a second testcase because
the diagnostics for fallthrough not used within switch at all is done during
expansion and expansion won't happen if there are other errors in the
testcase.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
2024-09-05 Jakub Jelinek <ja...@redhat.com>
PR c++/110345
* g++.dg/cpp0x/attr-fallthrough1.C: New test.
* g++.dg/cpp0x/attr-fallthrough2.C: New test.
--- gcc/testsuite/g++.dg/cpp0x/attr-fallthrough1.C.jj 2024-09-04
16:27:52.786654084 +0200
+++ gcc/testsuite/g++.dg/cpp0x/attr-fallthrough1.C 2024-09-04
16:44:41.879666097 +0200
@@ -0,0 +1,169 @@
+// 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
+foo (int n)
+{
+ switch (n)
+ {
+ case 1:
+ [[fallthrough (n > 0)]]; // { dg-error "'fallthrough'
attribute does not take any arguments" }
+ case 2:
+ break;
+ case 3:
+ [[fallthrough]];
+ case 4:
+ break;
+ case 5:
+ [[fallthrough ("abc")]]; // { dg-error "'fallthrough'
attribute does not take any arguments" }
+ case 6:
+ break;
+ case 7:
+ [[fallthrough (1, 2, 3)]]; // { dg-error "'fallthrough'
attribute does not take any arguments" }
+ case 8:
+ [[fallthrough]]; // { dg-error "attribute
'fallthrough' not preceding a case label or default label" }
+ foo (n - 1);
+ break;
+ default:
+ break;
+ }
+
+ [[fallthrough]] int x1; // { dg-error "'fallthrough'
attribute ignored" }
+
+ auto a = [] [[fallthrough]] () {}; // { dg-error "'fallthrough'
attribute ignored" }
+ auto b = [] constexpr [[fallthrough]] {}; // { dg-error "'fallthrough'
attribute ignored" }
+ // { 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 [[fallthrough]] {}; // { dg-error "'fallthrough'
attribute ignored" }
+ // { dg-error "parameter declaration before
lambda exception specification only optional with" "" { target c++20_down } .-1 }
+ auto d = [] () [[fallthrough]] {}; // { dg-error "'fallthrough'
attribute ignored" }
+ auto e = new int [n] [[fallthrough]]; // { dg-warning "attributes
ignored on outermost array type in new expression" }
+ auto e2 = new int [n] [[fallthrough]] [42]; // { dg-warning "attributes ignored
on outermost array type in new expression" }
+ auto f = new int [n][42] [[fallthrough]]; // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] {} // { dg-warning "attributes at the
beginning of statement are ignored" }
+ [[fallthrough]] if (true) {} // { dg-warning "attributes at the
beginning of statement are ignored" }
+ [[fallthrough]] while (false) {} // { dg-warning "attributes at the
beginning of statement are ignored" }
+ [[fallthrough]] goto lab; // { dg-warning "attributes at the
beginning of statement are ignored" }
+ [[fallthrough]] lab:; // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] try {} catch (int) {} // { dg-warning "attributes
at the beginning of statement are ignored" }
+ if ([[fallthrough]] int x = 0) {} // { dg-error "'fallthrough'
attribute ignored" }
+ switch (n)
+ {
+ [[fallthrough]] case 1: // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] break; // { dg-warning "attributes at the
beginning of statement are ignored" }
+ [[fallthrough]] default: // { dg-error "'fallthrough'
attribute ignored" }
+ break;
+ }
+ for ([[fallthrough]] auto a : arr) {} // { dg-error "'fallthrough'
attribute ignored" }
+ for ([[fallthrough]] auto [a, b] : arr2) {} // { dg-error "'fallthrough'
attribute ignored" }
+ // { dg-error "structured bindings only
available with" "" { target c++14_down } .-1 }
+ [[fallthrough]] asm (""); // { dg-warning "attributes ignored on
'asm' declaration" }
+ try {} catch ([[fallthrough]] int x) {} // { dg-error "'fallthrough'
attribute ignored" }
+ try {} catch ([[fallthrough]] int) {} // { dg-error "'fallthrough'
attribute ignored" }
+ try {} catch (int [[fallthrough]] x) {} // { dg-warning "attribute
ignored" }
+ try {} catch (int [[fallthrough]]) {} // { dg-warning "attribute
ignored" }
+ try {} catch (int x [[fallthrough]]) {} // { dg-error "'fallthrough'
attribute ignored" }
+}
+
+[[fallthrough]] int bar (); // { dg-error "'fallthrough'
attribute ignored" }
+using foobar [[fallthrough]] = int; // { dg-error "'fallthrough'
attribute ignored" }
+[[fallthrough]] int a; // { dg-error "'fallthrough'
attribute ignored" }
+[[fallthrough]] auto [b, c] = arr; // { dg-error "'fallthrough'
attribute ignored" }
+ // { dg-error "structured bindings only
available with" "" { target c++14_down } .-1 }
+[[fallthrough]]; // { dg-warning "attribute
ignored" }
+inline [[fallthrough]] void baz () {} // { dg-warning "attribute
ignored" }
+ // { dg-error "standard attributes in middle
of decl-specifiers" "" { target *-*-* } .-1 }
+constexpr [[fallthrough]] int qux () { return 0; } // { dg-warning "attribute
ignored" }
+ // { dg-error "standard attributes in middle
of decl-specifiers" "" { target *-*-* } .-1 }
+int [[fallthrough]] d; // { dg-warning "attribute
ignored" }
+int const [[fallthrough]] e = 1; // { dg-warning "attribute
ignored" }
+struct A {} [[fallthrough]]; // { dg-warning "attribute ignored
in declaration of 'struct A'" }
+struct A [[fallthrough]]; // { dg-warning "attribute
ignored" }
+struct A [[fallthrough]] a1; // { dg-warning "attribute
ignored" }
+A [[fallthrough]] a2; // { dg-warning "attribute
ignored" }
+enum B { B0 } [[fallthrough]]; // { dg-warning "attribute ignored
in declaration of 'enum B'" }
+enum B [[fallthrough]]; // { dg-warning "attribute
ignored" }
+enum B [[fallthrough]] b1; // { dg-warning "attribute
ignored" }
+B [[fallthrough]] b2; // { dg-warning "attribute
ignored" }
+struct [[fallthrough]] C {}; // { dg-error "'fallthrough'
attribute ignored" }
+int f [[fallthrough]]; // { dg-error "'fallthrough'
attribute ignored" }
+int g[2] [[fallthrough]]; // { dg-error "'fallthrough'
attribute ignored" }
+int g2 [[fallthrough]] [2]; // { dg-error "'fallthrough'
attribute ignored" }
+int corge () [[fallthrough]]; // { dg-error "'fallthrough'
attribute ignored" }
+int *[[fallthrough]] h; // { dg-error "'fallthrough'
attribute ignored" }
+int & [[fallthrough]] i = f; // { dg-error "'fallthrough'
attribute ignored" }
+int && [[fallthrough]] j = 0; // { dg-error "'fallthrough'
attribute ignored" }
+int S::* [[fallthrough]] k; // { dg-error "'fallthrough'
attribute ignored" }
+auto l = sizeof (int [2] [[fallthrough]]); // { dg-error "'fallthrough'
attribute ignored" }
+int freddy ([[fallthrough]] int a, // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] int, // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] int c = 0, // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] int = 0); // { dg-error "'fallthrough'
attribute ignored" }
+void
+corge ([[fallthrough]] int a, // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] int, // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] int c = 0, // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] int = 0) // { dg-error "'fallthrough'
attribute ignored" }
+{
+}
+[[fallthrough]] void
+garply () // { dg-error "'fallthrough'
attribute ignored" }
+{
+}
+int grault (int [[fallthrough]] a, // { dg-warning "attribute
ignored" }
+ int [[fallthrough]], // { dg-warning "attribute
ignored" }
+ int [[fallthrough]] c = 0, // { dg-warning "attribute
ignored" }
+ int [[fallthrough]] = 0); // { dg-warning "attribute
ignored" }
+void
+waldo (int [[fallthrough]] a, // { dg-warning "attribute
ignored" }
+ int [[fallthrough]], // { dg-warning "attribute
ignored" }
+ int [[fallthrough]] c = 0, // { dg-warning "attribute
ignored" }
+ int [[fallthrough]] = 0) // { dg-warning "attribute
ignored" }
+{
+}
+int plugh (int a [[fallthrough]], // { dg-error "'fallthrough'
attribute ignored" }
+ int b [[fallthrough]] = 0); // { dg-error "'fallthrough'
attribute ignored" }
+void
+thud (int a [[fallthrough]], // { dg-error "'fallthrough'
attribute ignored" }
+ int b [[fallthrough]] = 0) // { dg-error "'fallthrough'
attribute ignored" }
+{
+}
+enum [[fallthrough]] D { D0 }; // { dg-error "'fallthrough'
attribute ignored" }
+enum class [[fallthrough]] E { E0 }; // { dg-error "'fallthrough'
attribute ignored" }
+enum F {};
+enum [[fallthrough]] F; // { dg-warning "type
attributes ignored after type is already defined" }
+enum G {
+ G0 [[fallthrough]], // { dg-error "'fallthrough'
attribute ignored" }
+ G1 [[fallthrough]] = 2 // { dg-error "'fallthrough'
attribute ignored" }
+};
+namespace [[fallthrough]] H { using H0 = int; } // { dg-warning
"'fallthrough' attribute directive ignored" } */
+namespace [[fallthrough]] {} // { dg-warning "'fallthrough'
attribute directive ignored" }
+[[fallthrough]] using namespace H; // { dg-warning "'fallthrough'
attribute directive ignored" }
+struct [[fallthrough]] I // { dg-error "'fallthrough'
attribute ignored" }
+{
+ [[fallthrough]]; // { dg-error "declaration does not
declare anything" }
+ [[fallthrough]] int i; // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] int foo (); // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] int bar () { return 1; } // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] int : 0; // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] int i2 : 5; // { dg-error "'fallthrough'
attribute ignored" }
+ [[fallthrough]] static int i3; // { dg-error "'fallthrough'
attribute ignored" }
+ static int i4;
+};
+[[fallthrough]] int I::i4 = 0; // { dg-error "'fallthrough'
attribute ignored" }
+struct J : [[fallthrough]] C {}; // { dg-warning "attributes on base
specifiers are ignored" }
+#if __cpp_concepts >= 201907L
+template <typename T>
+concept K [[fallthrough]] = requires { true; }; // { dg-error "'fallthrough' attribute
ignored" "" { target c++20 } }
+#endif
+typedef int L [[fallthrough]]; // { dg-error "'fallthrough'
attribute ignored" }
+template <typename T>
+struct M {};
+template <>
+struct [[fallthrough]] M<int> { int m; }; // { dg-error "'fallthrough'
attribute ignored" }
+typedef int N[2] [[fallthrough]]; // { dg-error "'fallthrough'
attribute ignored" }
+typedef int O [[fallthrough]] [2]; // { dg-error "'fallthrough'
attribute ignored" }
--- gcc/testsuite/g++.dg/cpp0x/attr-fallthrough2.C.jj 2024-09-04
16:46:49.540022110 +0200
+++ gcc/testsuite/g++.dg/cpp0x/attr-fallthrough2.C 2024-09-04
16:46:45.707071471 +0200
@@ -0,0 +1,10 @@
+// C++ 26 P2552R3 - On the ignorability of standard attributes
+// { dg-do compile { target c++11 } }
+
+void
+foo ()
+{
+ [[fallthrough]]; // { dg-error "invalid use of attribute
'fallthrough'" }
+lab:;
+ goto lab;
+}
Jakub
