On Mon, Aug 19, 2024 at 05:05:51PM -0400, Jason Merrill wrote:
> > I've tried to compile it also with latest clang and there is agreement in
> > most of the diagnostics, just at block scope (inside of foo) it doesn't
> > diagnose
> > auto e = new int [n] [[deprecated]];
> > auto e2 = new int [n] [[deprecated]] [42];
> > [[deprecated]] lab:;
> > and at namespace scope
> > [[deprecated]];
> > I think that all feels like clang++ bug.
> > On the other side, clang++ diagnoses
> > enum B { B0 } [[deprecated]];
> > but GCC with all the patches I've posted today doesn't, is that a GCC bug?
>
> I think so, yes.
Fixed in the just posted 2 patches.
> > The FIXMEs are where there is agreement with clang++, but I'm not sure.
> > One thing is I'm not sure if "a variable" above is meant to include function
> > parameters, and/or unused function parameters without a specified name,
> > function parameters inside of a function declaration rather than definition
> > and/or static data members.
>
> All of those, I believe.
Removed the FIXMEs.
> > Also unsure about
> > [[deprecated]] int : 0;
> > at class scope, that isn't a non-static data member...
>
> Indeed, pedantically the standard says it can't apply to an unnamed
> bit-field.
And the following updated version on top of the
https://gcc.gnu.org/pipermail/gcc-patches/2024-August/661904.html
https://gcc.gnu.org/pipermail/gcc-patches/2024-August/661905.html
patches also diagnoses the attribute on unnamed bit-fields.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2024-08-30 Jakub Jelinek <ja...@redhat.com>
PR c++/110345
* parser.cc (cp_parser_std_attribute): Don't transform
[[deprecated]] into [[gnu::deprecated]].
* tree.cc (handle_std_deprecated_attribute): New function.
(std_attributes): Add deprecated entry.
* g++.dg/cpp0x/attr-deprecated1.C: New test.
--- gcc/cp/parser.cc.jj 2024-08-30 11:13:18.612089567 +0200
+++ gcc/cp/parser.cc 2024-08-30 12:55:17.875362909 +0200
@@ -30357,12 +30357,11 @@ cp_parser_std_attribute (cp_parser *pars
/* We used to treat C++11 noreturn attribute as equivalent to GNU's,
but no longer: we have to be able to tell [[noreturn]] and
- __attribute__((noreturn)) apart. */
- /* C++14 deprecated attribute is equivalent to GNU's. */
- if (is_attribute_p ("deprecated", attr_id))
- TREE_PURPOSE (TREE_PURPOSE (attribute)) = gnu_identifier;
+ __attribute__((noreturn)) apart.
+ Similarly for C++14 deprecated attribute, we need to emit extra
+ diagnostics for [[deprecated]] compared to [[gnu::deprecated]]. */
/* C++17 fallthrough attribute is equivalent to GNU's. */
- else if (is_attribute_p ("fallthrough", attr_id))
+ if (is_attribute_p ("fallthrough", attr_id))
TREE_PURPOSE (TREE_PURPOSE (attribute)) = gnu_identifier;
/* C++23 assume attribute is equivalent to GNU's. */
else if (is_attribute_p ("assume", attr_id))
--- gcc/cp/tree.cc.jj 2024-08-15 22:23:07.908239976 +0200
+++ gcc/cp/tree.cc 2024-08-30 13:15:26.863829810 +0200
@@ -5087,6 +5087,25 @@ handle_likeliness_attribute (tree *node,
return error_mark_node;
}
+/* The C++14 [[deprecated]] attribute mostly maps to the GNU deprecated
+ attribute. */
+
+static tree
+handle_std_deprecated_attribute (tree *node, tree name, tree args, int flags,
+ bool *no_add_attrs)
+{
+ tree t = *node;
+ tree ret = handle_deprecated_attribute (node, name, args, flags,
+ no_add_attrs);
+ if (TYPE_P (*node) && t != *node)
+ pedwarn (input_location, OPT_Wattributes,
+ "%qE on a type other than class or enumeration definition", name);
+ else if (TREE_CODE (*node) == FIELD_DECL && DECL_UNNAMED_BIT_FIELD (*node))
+ pedwarn (input_location, OPT_Wattributes, "%qE on unnamed bit-field",
+ name);
+ return ret;
+}
+
/* Table of valid C++ attributes. */
static const attribute_spec cxx_gnu_attributes[] =
{
@@ -5110,6 +5129,8 @@ static const attribute_spec std_attribut
{
/* { name, min_len, max_len, decl_req, type_req, fn_type_req,
affects_type_identity, handler, exclude } */
+ { "deprecated", 0, 1, false, false, false, false,
+ handle_std_deprecated_attribute, NULL },
{ "maybe_unused", 0, 0, false, false, false, false,
handle_unused_attribute, NULL },
{ "nodiscard", 0, 1, false, false, false, false,
--- gcc/testsuite/g++.dg/cpp0x/attr-deprecated1.C.jj 2024-08-30
12:55:17.877362884 +0200
+++ gcc/testsuite/g++.dg/cpp0x/attr-deprecated1.C 2024-08-30
16:05:10.939240604 +0200
@@ -0,0 +1,131 @@
+// 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)
+{
+ [[deprecated]] int x1;
+ [[deprecated ("foobar")]] int x2;
+ [[deprecated (0)]] int x3; // { dg-error "deprecated
message is not a string" }
+ // { dg-error "expected
string-literal before numeric constant" "" { target c++26 } .-1 }
+ [[deprecated ("foo", "bar", "baz")]] int x4; // { dg-error "wrong number of
arguments specified for 'deprecated' attribute" }
+ [[deprecated (0, 1, 2)]] int x5; // { dg-error "wrong number of
arguments specified for 'deprecated' attribute" }
+ // { dg-error "expected
string-literal before numeric constant" "" { target c++26 } .-1 }
+
+ auto a = [] [[deprecated]] () {};
+ auto b = [] constexpr [[deprecated]] {}; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+ // { 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 [[deprecated]] {}; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+ // { dg-error "parameter
declaration before lambda exception specification only optional with" "" {
target c++20_down } .-1 }
+ auto d = [] () [[deprecated]] {}; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+ auto e = new int [n] [[deprecated]]; // { dg-warning "attributes
ignored on outermost array type in new expression" }
+ auto e2 = new int [n] [[deprecated]] [42]; // { dg-warning "attributes
ignored on outermost array type in new expression" }
+ auto f = new int [n][42] [[deprecated]]; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+ [[deprecated]]; // { dg-warning "attributes at
the beginning of statement are ignored" }
+ [[deprecated]] {} // { dg-warning "attributes at
the beginning of statement are ignored" }
+ [[deprecated]] if (true) {} // { dg-warning "attributes at
the beginning of statement are ignored" }
+ [[deprecated]] while (false) {} // { dg-warning "attributes at
the beginning of statement are ignored" }
+ [[deprecated]] goto lab; // { dg-warning "attributes at
the beginning of statement are ignored" }
+ [[deprecated]] lab:; // { dg-error "'deprecated'
attribute ignored" }
+ [[deprecated]] try {} catch (int) {} // { dg-warning "attributes at
the beginning of statement are ignored" }
+ if ([[deprecated]] int x = 0) {}
+ switch (n)
+ {
+ [[deprecated]] case 1: // { dg-error "'deprecated'
attribute ignored" }
+ [[deprecated]] break; // { dg-warning "attributes at
the beginning of statement are ignored" }
+ [[deprecated]] default: // { dg-error "'deprecated'
attribute ignored" }
+ break;
+ }
+ for ([[deprecated]] auto a : arr) {}
+ for ([[deprecated]] auto [a, b] : arr2) {} // { dg-error "structured
bindings only available with" "" { target c++14_down } }
+ [[deprecated]] asm (""); // { dg-warning "attributes
ignored on 'asm' declaration" }
+ try {} catch ([[deprecated]] int x) {}
+ try {} catch ([[deprecated]] int) {}
+}
+
+[[deprecated]] int bar ();
+using foobar [[deprecated]] = int;
+[[deprecated]] int a;
+[[deprecated]] auto [b, c] = arr; // { dg-error "structured
bindings only available with" "" { target c++14_down } }
+[[deprecated]]; // { dg-warning
"attribute ignored" }
+inline [[deprecated]] void baz () {} // { dg-warning "attribute
ignored" }
+ // { dg-error "standard
attributes in middle of decl-specifiers" "" { target *-*-* } .-1 }
+constexpr [[deprecated]] int qux () { return 0; } // { dg-warning
"attribute ignored" }
+ // { dg-error "standard
attributes in middle of decl-specifiers" "" { target *-*-* } .-1 }
+int [[deprecated]] d; // { dg-warning "attribute
ignored" }
+int const [[deprecated]] e = 1; // { dg-warning
"attribute ignored" }
+struct A {} [[deprecated]]; // { dg-warning "attribute
ignored in declaration of 'struct A'" }
+struct A [[deprecated]]; // { dg-warning "attribute
ignored" }
+struct A [[deprecated]] a1; // { dg-warning "attribute
ignored" }
+A [[deprecated]] a2; // { dg-warning "attribute
ignored" }
+enum B { B0 } [[deprecated]]; // { dg-warning "attribute
ignored in declaration of 'enum B'" }
+enum B [[deprecated]]; // { dg-warning "attribute
ignored" }
+enum B [[deprecated]] b1; // { dg-warning "attribute
ignored" }
+B [[deprecated]] b2; // { dg-warning "attribute
ignored" }
+struct [[deprecated]] C {};
+int f [[deprecated]];
+int g[2] [[deprecated]]; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+int g2 [[deprecated]] [2];
+int corge () [[deprecated]]; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+int *[[deprecated]] h; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+int & [[deprecated]] i = f; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+ // { dg-warning "'f' is
deprecated" "" { target *-*-* } .-1 }
+int && [[deprecated]] j = 0; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+int S::* [[deprecated]] k; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+auto l = sizeof (int [2] [[deprecated]]); // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+int freddy ([[deprecated]] int a,
+ [[deprecated]] int,
+ [[deprecated]] int c = 0,
+ [[deprecated]] int = 0);
+void
+corge ([[deprecated]] int a,
+ [[deprecated]] int,
+ [[deprecated]] int c = 0,
+ [[deprecated]] int = 0)
+{
+}
+[[deprecated]] void
+garply ()
+{
+}
+enum [[deprecated]] D { D0 };
+enum class [[deprecated]] E { E0 };
+enum F {};
+enum [[deprecated]] F; // { dg-warning "type
attributes ignored after type is already defined" }
+enum G {
+ G0 [[deprecated]],
+ G1 [[deprecated]] = 2
+};
+namespace [[deprecated]] H { using H0 = int; }
+namespace [[deprecated]] {} // { dg-warning "ignoring
'deprecated' attribute on anonymous namespace" }
+[[deprecated]] using namespace H; // { dg-warning "'deprecated'
attribute directive ignored" }
+ // { dg-warning "'H' is
deprecated" "" { target *-*-* } .-1 }
+struct [[deprecated]] I
+{
+ [[deprecated]]; // { dg-error "declaration does
not declare anything" }
+ [[deprecated]] int i;
+ [[deprecated]] int foo ();
+ [[deprecated]] int bar () { return 1; }
+ [[deprecated]] int : 0; // { dg-error "'deprecated' on
unnamed bit-field" }
+ [[deprecated]] int i2 : 5;
+ [[deprecated]] static int i3;
+ static int i4;
+};
+[[deprecated]] int I::i4 = 0;
+struct J : [[deprecated]] C {}; // { dg-warning
"attributes on base specifiers are ignored" }
+#if __cpp_concepts >= 201907L
+template <typename T>
+concept K [[deprecated]] = requires { true; };
+#endif
+typedef int L [[deprecated]];
+template <typename T>
+struct M {};
+template <>
+struct [[deprecated]] M<int> { int m; };
+typedef int N[2] [[deprecated]]; // { dg-error "'deprecated' on
a type other than class or enumeration definition" }
+typedef int O [[deprecated]] [2];
Jakub
