https://gcc.gnu.org/g:0cf68222d2df3af7fefad28a82fcd51d8b40a192
commit r15-1190-g0cf68222d2df3af7fefad28a82fcd51d8b40a192
Author: Joseph Myers <josmy...@redhat.com>
Date: Tue Jun 11 23:00:04 2024 +0000
c: Add -std=c2y, -std=gnu2y, -Wc23-c2y-compat, C2Y _Generic with type
operand
The first new C2Y feature, _Generic where the controlling operand is a
type name rather than an expression (as defined in N3260), was voted
into C2Y today. (In particular, this form of _Generic allows
distinguishing qualified and unqualified versions of a type.) This
feature also includes allowing the generic associations to specify
incomplete and function types.
Add this feature to GCC, along with the -std=c2y, -std=gnu2y and
-Wc23-c2y-compat options to control when and how it is diagnosed. As
usual, the feature is allowed by default in older standards modes,
subject to diagnosis with -pedantic, -pedantic-errors or
-Wc23-c2y-compat.
Bootstrapped with no regressions on x86_64-pc-linux-gnu.
gcc/
* doc/cpp.texi (__STDC_VERSION__): Document C2Y handling.
* doc/invoke.texi (-Wc23-c2y-compat, -std=c2y, -std=gnu2y):
Document options.
(-std=gnu23): Update documentation.
* doc/standards.texi (C Language): Document C2Y. Update C23
description.
* config/rl78/rl78.cc (rl78_option_override): Handle "GNU C2Y"
language name.
* dwarf2out.cc (highest_c_language, gen_compile_unit_die):
Likewise.
gcc/c-family/
* c-common.cc (flag_isoc2y): New.
(flag_isoc99, flag_isoc11, flag_isoc23): Update comments.
* c-common.h (flag_isoc2y): New.
(clk_c, flag_isoc23): Update comments.
* c-opts.cc (set_std_c2y): New.
(c_common_handle_option): Handle OPT_std_c2y and OPT_std_gnu2y.
(set_std_c89, set_std_c99, set_std_c11, set_std_c17, set_std_c23):
Set flag_isoc2y.
(set_std_c23): Update comment.
* c.opt (Wc23-c2y-compat, std=c2y, std=gnu2y): New.
* c.opt.urls: Regenerate.
gcc/c/
* c-errors.cc (pedwarn_c23): New.
* c-parser.cc (disable_extension_diagnostics)
(restore_extension_diagnostics): Save and restore
warn_c23_c2y_compat.
(c_parser_generic_selection): Handle type name as controlling
operand. Allow incomplete and function types subject to
pedwarn_c23 calls.
* c-tree.h (pedwarn_c23): New.
gcc/testsuite/
* gcc.dg/c23-generic-1.c, gcc.dg/c23-generic-2.c,
gcc.dg/c23-generic-3.c, gcc.dg/c23-generic-4.c,
gcc.dg/c2y-generic-1.c, gcc.dg/c2y-generic-2.c,
gcc.dg/c2y-generic-3.c, gcc.dg/gnu2y-generic-1.c: New tests.
* gcc.dg/c23-tag-6.c: Use -pedantic-errors.
libcpp/
* include/cpplib.h (CLK_GNUC2Y, CLK_STDC2Y): New.
* init.cc (lang_defaults): Add GNUC2Y and STDC2Y entries.
(cpp_init_builtins): Define __STDC_VERSION__ to 202500L for GNUC2Y
and STDC2Y.
Diff:
---
gcc/c-family/c-common.cc | 10 +++--
gcc/c-family/c-common.h | 8 +++-
gcc/c-family/c-opts.cc | 34 +++++++++++++-
gcc/c-family/c.opt | 12 +++++
gcc/c-family/c.opt.urls | 3 ++
gcc/c/c-errors.cc | 39 ++++++++++++++++
gcc/c/c-parser.cc | 82 ++++++++++++++++++++++------------
gcc/c/c-tree.h | 2 +
gcc/config/rl78/rl78.cc | 1 +
gcc/doc/cpp.texi | 4 +-
gcc/doc/invoke.texi | 23 +++++++++-
gcc/doc/standards.texi | 8 +++-
gcc/dwarf2out.cc | 5 ++-
gcc/testsuite/gcc.dg/c23-generic-1.c | 17 +++++++
gcc/testsuite/gcc.dg/c23-generic-2.c | 17 +++++++
gcc/testsuite/gcc.dg/c23-generic-3.c | 16 +++++++
gcc/testsuite/gcc.dg/c23-generic-4.c | 16 +++++++
gcc/testsuite/gcc.dg/c23-tag-6.c | 2 +-
gcc/testsuite/gcc.dg/c2y-generic-1.c | 15 +++++++
gcc/testsuite/gcc.dg/c2y-generic-2.c | 17 +++++++
gcc/testsuite/gcc.dg/c2y-generic-3.c | 9 ++++
gcc/testsuite/gcc.dg/gnu2y-generic-1.c | 15 +++++++
libcpp/include/cpplib.h | 3 +-
libcpp/init.cc | 5 +++
24 files changed, 323 insertions(+), 40 deletions(-)
diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc
index 0341c44a2cd9..24335deeb582 100644
--- a/gcc/c-family/c-common.cc
+++ b/gcc/c-family/c-common.cc
@@ -216,18 +216,22 @@ int flag_cond_mismatch;
int flag_isoc94;
-/* Nonzero means use the ISO C99 (or C11) dialect of C. */
+/* Nonzero means use the ISO C99 (or later) dialect of C. */
int flag_isoc99;
-/* Nonzero means use the ISO C11 dialect of C. */
+/* Nonzero means use the ISO C11 (or later) dialect of C. */
int flag_isoc11;
-/* Nonzero means use the ISO C23 dialect of C. */
+/* Nonzero means use the ISO C23 (or later) dialect of C. */
int flag_isoc23;
+/* Nonzero means use the ISO C2Y (or later) dialect of C. */
+
+int flag_isoc2y;
+
/* Nonzero means that we have builtin functions, and main is an int. */
int flag_hosted = 1;
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index ae79912c89f6..48c89b603bcd 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -531,7 +531,7 @@ extern GTY(()) tree c_global_trees[CTI_MAX];
enum c_language_kind
{
- clk_c = 0, /* C90, C94, C99, C11 or C23 */
+ clk_c = 0, /* C without ObjC features. */
clk_objc = 1, /* clk_c with ObjC features. */
clk_cxx = 2, /* ANSI/ISO C++ */
clk_objcxx = 3 /* clk_cxx with ObjC features. */
@@ -676,10 +676,14 @@ extern int flag_isoc99;
extern int flag_isoc11;
-/* Nonzero means use the ISO C23 dialect of C. */
+/* Nonzero means use the ISO C23 (or later) dialect of C. */
extern int flag_isoc23;
+/* Nonzero means use the ISO C2Y (or later) dialect of C. */
+
+extern int flag_isoc2y;
+
/* Nonzero means that we have builtin functions, and main is an int. */
extern int flag_hosted;
diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc
index be3058dca637..faaf9ee63509 100644
--- a/gcc/c-family/c-opts.cc
+++ b/gcc/c-family/c-opts.cc
@@ -121,6 +121,7 @@ static void set_std_c99 (int);
static void set_std_c11 (int);
static void set_std_c17 (int);
static void set_std_c23 (int);
+static void set_std_c2y (int);
static void check_deps_environment_vars (void);
static void handle_deferred_opts (void);
static void sanitize_cpp_opts (void);
@@ -743,6 +744,16 @@ c_common_handle_option (size_t scode, const char *arg,
HOST_WIDE_INT value,
set_std_c23 (false /* ISO */);
break;
+ case OPT_std_c2y:
+ if (!preprocessing_asm_p)
+ set_std_c2y (true /* ISO */);
+ break;
+
+ case OPT_std_gnu2y:
+ if (!preprocessing_asm_p)
+ set_std_c2y (false /* ISO */);
+ break;
+
case OPT_trigraphs:
cpp_opts->trigraphs = 1;
break;
@@ -1782,6 +1793,7 @@ set_std_c89 (int c94, int iso)
flag_isoc99 = 0;
flag_isoc11 = 0;
flag_isoc23 = 0;
+ flag_isoc2y = 0;
lang_hooks.name = "GNU C89";
}
@@ -1793,6 +1805,7 @@ set_std_c99 (int iso)
flag_no_asm = iso;
flag_no_nonansi_builtin = iso;
flag_iso = iso;
+ flag_isoc2y = 0;
flag_isoc23 = 0;
flag_isoc11 = 0;
flag_isoc99 = 1;
@@ -1808,6 +1821,7 @@ set_std_c11 (int iso)
flag_no_asm = iso;
flag_no_nonansi_builtin = iso;
flag_iso = iso;
+ flag_isoc2y = 0;
flag_isoc23 = 0;
flag_isoc11 = 1;
flag_isoc99 = 1;
@@ -1823,6 +1837,7 @@ set_std_c17 (int iso)
flag_no_asm = iso;
flag_no_nonansi_builtin = iso;
flag_iso = iso;
+ flag_isoc2y = 0;
flag_isoc23 = 0;
flag_isoc11 = 1;
flag_isoc99 = 1;
@@ -1830,7 +1845,7 @@ set_std_c17 (int iso)
lang_hooks.name = "GNU C17";
}
-/* Set the C 2X standard (without GNU extensions if ISO). */
+/* Set the C 23 standard (without GNU extensions if ISO). */
static void
set_std_c23 (int iso)
{
@@ -1838,6 +1853,7 @@ set_std_c23 (int iso)
flag_no_asm = iso;
flag_no_nonansi_builtin = iso;
flag_iso = iso;
+ flag_isoc2y = 0;
flag_isoc23 = 1;
flag_isoc11 = 1;
flag_isoc99 = 1;
@@ -1845,6 +1861,22 @@ set_std_c23 (int iso)
lang_hooks.name = "GNU C23";
}
+/* Set the C 2Y standard (without GNU extensions if ISO). */
+static void
+set_std_c2y (int iso)
+{
+ cpp_set_lang (parse_in, iso ? CLK_STDC23: CLK_GNUC23);
+ flag_no_asm = iso;
+ flag_no_nonansi_builtin = iso;
+ flag_iso = iso;
+ flag_isoc2y = 1;
+ flag_isoc23 = 1;
+ flag_isoc11 = 1;
+ flag_isoc99 = 1;
+ flag_isoc94 = 1;
+ lang_hooks.name = "GNU C2Y";
+}
+
/* Set the C++ 98 standard (without GNU extensions if ISO). */
static void
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index fb34c3b70319..b067369fa7ea 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -441,6 +441,10 @@ Wc11-c2x-compat
C ObjC Alias(Wc11-c23-compat)
Deprecated in favor of -Wc11-c23-compat.
+Wc23-c2y-compat
+C ObjC Var(warn_c23_c2y_compat) Init(-1) Warning
+Warn about features not present in ISO C23, but present in ISO C2Y.
+
Wc90-c99-compat
C ObjC CPP(cpp_warn_c90_c99_compat) CppReason(CPP_W_C90_C99_COMPAT)
Var(warn_c90_c99_compat) Init(-1) Warning
Warn about features not present in ISO C90, but present in ISO C99.
@@ -2515,6 +2519,10 @@ std=c2x
C ObjC Alias(std=c23)
Deprecated in favor of -std=c23.
+std=c2y
+C ObjC
+Conform to the ISO 202Y C standard draft (experimental and incomplete support).
+
std=c89
C ObjC Alias(std=c90)
Conform to the ISO 1990 C standard.
@@ -2613,6 +2621,10 @@ std=gnu2x
C ObjC Alias(std=gnu23)
Deprecated in favor of -std=gnu23.
+std=gnu2y
+C ObjC
+Conform to the ISO 202Y C standard draft with GNU extensions (experimental and
incomplete support).
+
std=gnu89
C ObjC Alias(std=gnu90)
Conform to the ISO 1990 C standard with GNU extensions.
diff --git a/gcc/c-family/c.opt.urls b/gcc/c-family/c.opt.urls
index dd455d7c0dc7..31d9ffef578f 100644
--- a/gcc/c-family/c.opt.urls
+++ b/gcc/c-family/c.opt.urls
@@ -160,6 +160,9 @@
UrlSuffix(gcc/Warning-Options.html#index-Wbuiltin-macro-redefined)
Wc11-c23-compat
UrlSuffix(gcc/Warning-Options.html#index-Wc11-c23-compat)
+Wc23-c2y-compat
+UrlSuffix(gcc/Warning-Options.html#index-Wc23-c2y-compat)
+
Wc90-c99-compat
UrlSuffix(gcc/Warning-Options.html#index-Wc90-c99-compat)
diff --git a/gcc/c/c-errors.cc b/gcc/c/c-errors.cc
index 7aa5e0db34e3..f36e7f9780a3 100644
--- a/gcc/c/c-errors.cc
+++ b/gcc/c/c-errors.cc
@@ -25,6 +25,45 @@ along with GCC; see the file COPYING3. If not see
#include "c-tree.h"
#include "opts.h"
+/* Issue an ISO C23 pedantic warning MSGID if -pedantic outside C2Y mode,
+ otherwise issue warning MSGID if -Wc23-c2y-compat is specified.
+ This function is supposed to be used for matters that are allowed in
+ ISO C2Y but not supported in ISO C23, thus we explicitly don't pedwarn
+ when C2Y is specified. */
+
+bool
+pedwarn_c23 (location_t location, int opt, const char *gmsgid, ...)
+{
+ diagnostic_info diagnostic;
+ va_list ap;
+ bool warned = false;
+ rich_location richloc (line_table, location);
+
+ va_start (ap, gmsgid);
+ /* If desired, issue the C23/C2Y compat warning, which is more specific
+ than -pedantic. */
+ if (warn_c23_c2y_compat > 0)
+ {
+ diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc,
+ (pedantic && !flag_isoc2y)
+ ? DK_PEDWARN : DK_WARNING);
+ diagnostic.option_index = OPT_Wc23_c2y_compat;
+ warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
+ }
+ /* -Wno-c23-c2y-compat suppresses even the pedwarns. */
+ else if (warn_c23_c2y_compat == 0)
+ ;
+ /* For -pedantic outside C2Y, issue a pedwarn. */
+ else if (pedantic && !flag_isoc2y)
+ {
+ diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc, DK_PEDWARN);
+ diagnostic.option_index = opt;
+ warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
+ }
+ va_end (ap);
+ return warned;
+}
+
/* Issue an ISO C11 pedantic warning MSGID if -pedantic outside C23 mode,
otherwise issue warning MSGID if -Wc11-c23-compat is specified.
This function is supposed to be used for matters that are allowed in
diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 0c5018134ccd..e83e9c683f75 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -1534,6 +1534,9 @@ disable_extension_diagnostics (void)
/* Similarly for warn_c11_c23_compat. */
| ((warn_c11_c23_compat == 1) << 11)
| ((warn_c11_c23_compat == -1) << 12)
+ /* Similarly for warn_c23_c2y_compat. */
+ | ((warn_c23_c2y_compat == 1) << 13)
+ | ((warn_c23_c2y_compat == -1) << 14)
);
cpp_opts->cpp_pedantic = pedantic = 0;
warn_pointer_arith = 0;
@@ -1545,6 +1548,7 @@ disable_extension_diagnostics (void)
warn_c90_c99_compat = 0;
warn_c99_c11_compat = 0;
warn_c11_c23_compat = 0;
+ warn_c23_c2y_compat = 0;
return ret;
}
@@ -1565,6 +1569,7 @@ restore_extension_diagnostics (int flags)
warn_c90_c99_compat = (flags >> 7) & 1 ? 1 : ((flags >> 8) & 1 ? -1 : 0);
warn_c99_c11_compat = (flags >> 9) & 1 ? 1 : ((flags >> 10) & 1 ? -1 : 0);
warn_c11_c23_compat = (flags >> 11) & 1 ? 1 : ((flags >> 12) & 1 ? -1 : 0);
+ warn_c23_c2y_compat = (flags >> 13) & 1 ? 1 : ((flags >> 14) & 1 ? -1 : 0);
}
/* Helper data structure for parsing #pragma acc routine. */
@@ -10273,8 +10278,14 @@ struct c_generic_association
/* Parse a generic-selection. (C11 6.5.1.1).
generic-selection:
- _Generic ( assignment-expression , generic-assoc-list )
-
+ _Generic ( generic-controlling-operand , generic-assoc-list )
+
+ generic-controlling-operand:
+ assignment-expression
+ type-name
+
+ (The use of a type-name is new in C2Y.)
+
generic-assoc-list:
generic-association
generic-assoc-list , generic-association
@@ -10314,30 +10325,43 @@ c_parser_generic_selection (c_parser *parser)
if (!parens.require_open (parser))
return error_expr;
- c_inhibit_evaluation_warnings++;
selector_loc = c_parser_peek_token (parser)->location;
- selector = c_parser_expr_no_commas (parser, NULL);
- selector = default_function_array_conversion (selector_loc, selector);
- c_inhibit_evaluation_warnings--;
-
- if (selector.value == error_mark_node)
+ if (c_parser_next_tokens_start_typename (parser, cla_prefer_id))
{
- c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
- return selector;
- }
- mark_exp_read (selector.value);
- selector_type = TREE_TYPE (selector.value);
- /* In ISO C terms, rvalues (including the controlling expression of
- _Generic) do not have qualified types. */
- if (TREE_CODE (selector_type) != ARRAY_TYPE)
- selector_type = TYPE_MAIN_VARIANT (selector_type);
- /* In ISO C terms, _Noreturn is not part of the type of expressions
- such as &abort, but in GCC it is represented internally as a type
- qualifier. */
- if (FUNCTION_POINTER_TYPE_P (selector_type)
- && TYPE_QUALS (TREE_TYPE (selector_type)) != TYPE_UNQUALIFIED)
- selector_type
- = build_pointer_type (TYPE_MAIN_VARIANT (TREE_TYPE (selector_type)));
+ c_inhibit_evaluation_warnings++;
+ pedwarn_c23 (selector_loc, OPT_Wpedantic,
+ "ISO C does not support use of type name as %<_Generic%> "
+ "controlling operand before C2Y");
+ struct c_type_name *type = c_parser_type_name (parser);
+ selector_type = groktypename (type, NULL, NULL);
+ c_inhibit_evaluation_warnings--;
+ }
+ else
+ {
+ c_inhibit_evaluation_warnings++;
+ selector = c_parser_expr_no_commas (parser, NULL);
+ selector = default_function_array_conversion (selector_loc, selector);
+ c_inhibit_evaluation_warnings--;
+
+ if (selector.value == error_mark_node)
+ {
+ c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
+ return selector;
+ }
+ mark_exp_read (selector.value);
+ selector_type = TREE_TYPE (selector.value);
+ /* In ISO C terms, rvalues (including the controlling expression
+ of _Generic) do not have qualified types. */
+ if (TREE_CODE (selector_type) != ARRAY_TYPE)
+ selector_type = TYPE_MAIN_VARIANT (selector_type);
+ /* In ISO C terms, _Noreturn is not part of the type of expressions
+ such as &abort, but in GCC it is represented internally as a type
+ qualifier. */
+ if (FUNCTION_POINTER_TYPE_P (selector_type)
+ && TYPE_QUALS (TREE_TYPE (selector_type)) != TYPE_UNQUALIFIED)
+ selector_type
+ = build_pointer_type (TYPE_MAIN_VARIANT (TREE_TYPE (selector_type)));
+ }
if (!c_parser_require (parser, CPP_COMMA, "expected %<,%>"))
{
@@ -10376,11 +10400,13 @@ c_parser_generic_selection (c_parser *parser)
}
if (TREE_CODE (assoc.type) == FUNCTION_TYPE)
- error_at (assoc.type_location,
- "%<_Generic%> association has function type");
+ pedwarn_c23 (assoc.type_location, OPT_Wpedantic,
+ "ISO C does not support %<_Generic%> association with "
+ "function type before C2Y");
else if (!COMPLETE_TYPE_P (assoc.type))
- error_at (assoc.type_location,
- "%<_Generic%> association has incomplete type");
+ pedwarn_c23 (assoc.type_location, OPT_Wpedantic,
+ "ISO C does not support %<_Generic%> association with "
+ "incomplete type before C2Y");
if (c_type_variably_modified_p (assoc.type))
error_at (assoc.type_location,
diff --git a/gcc/c/c-tree.h b/gcc/c/c-tree.h
index 56a33b8156c6..15da875a0290 100644
--- a/gcc/c/c-tree.h
+++ b/gcc/c/c-tree.h
@@ -905,6 +905,8 @@ extern bool pedwarn_c99 (location_t, int opt, const char *,
...)
ATTRIBUTE_GCC_DIAG(3,4);
extern bool pedwarn_c11 (location_t, int opt, const char *, ...)
ATTRIBUTE_GCC_DIAG(3,4);
+extern bool pedwarn_c23 (location_t, int opt, const char *, ...)
+ ATTRIBUTE_GCC_DIAG(3,4);
extern void
set_c_expr_source_range (c_expr *expr,
diff --git a/gcc/config/rl78/rl78.cc b/gcc/config/rl78/rl78.cc
index e5345bfa9dd9..b4bb145b5a69 100644
--- a/gcc/config/rl78/rl78.cc
+++ b/gcc/config/rl78/rl78.cc
@@ -367,6 +367,7 @@ rl78_option_override (void)
&& strcmp (lang_hooks.name, "GNU C11")
&& strcmp (lang_hooks.name, "GNU C17")
&& strcmp (lang_hooks.name, "GNU C23")
+ && strcmp (lang_hooks.name, "GNU C2Y")
&& strcmp (lang_hooks.name, "GNU C89")
&& strcmp (lang_hooks.name, "GNU C99")
/* Compiling with -flto results in a language of GNU GIMPLE being
used... */
diff --git a/gcc/doc/cpp.texi b/gcc/doc/cpp.texi
index 3f38ca37feaf..a99c8dfdbe33 100644
--- a/gcc/doc/cpp.texi
+++ b/gcc/doc/cpp.texi
@@ -1887,7 +1887,9 @@ signifies the 2011 revision of the C standard; the value
@code{201710L} signifies the 2017 revision of the C standard (which is
otherwise identical to the 2011 version apart from correction of
defects). The value @code{202311L} is used for the experimental
-@option{-std=c23} and @option{-std=gnu23} modes.
+@option{-std=c23} and @option{-std=gnu23} modes. An unspecified value
+larger than @code{202311L} is used for the experimental
+@option{-std=c2y} and @option{-std=gnu2y} modes.
This macro is not defined if the @option{-traditional-cpp} option is
used, nor when compiling C++ or Objective-C@.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index a0b375646468..26e6a349d51d 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -340,7 +340,7 @@ Objective-C and Objective-C++ Dialects}.
-Wbool-compare -Wbool-operation
-Wno-builtin-declaration-mismatch
-Wno-builtin-macro-redefined -Wc90-c99-compat -Wc99-c11-compat
--Wc11-c23-compat
+-Wc11-c23-compat -Wc23-c2y-compat
-Wc++-compat -Wc++11-compat -Wc++14-compat -Wc++17-compat
-Wc++20-compat
-Wno-c++11-extensions -Wno-c++14-extensions -Wno-c++17-extensions
@@ -2472,6 +2472,10 @@ ISO C23, the 2023 revision of the ISO C standard
(expected to be
published in 2024). The support for this version is experimental and
incomplete. The name @samp{c2x} is deprecated.
+@item c2y
+The next version of the ISO C standard, still under development. The
+support for this version is experimental and incomplete.
+
@item gnu90
@itemx gnu89
GNU dialect of ISO C90 (including some C99 features).
@@ -2491,6 +2495,10 @@ GNU dialect of ISO C17. This is the default for C code.
@item gnu23
@itemx gnu2x
+GNU dialect of ISO C23. The support for this version is experimental
+and incomplete. The name @samp{gnu2x} is deprecated.
+
+@item gnu2y
The next version of the ISO C standard, still under development, plus
GNU extensions. The support for this version is experimental and
incomplete. The name @samp{gnu2x} is deprecated.
@@ -9326,6 +9334,19 @@ deprecated.
When not compiling in C23 mode, these warnings are upgraded to errors
by @option{-pedantic-errors}.
+@opindex Wc23-c2y-compat
+@opindex Wno-c23-c2y-compat
+@item -Wc23-c2y-compat @r{(C and Objective-C only)}
+@itemx -Wc23-c2y-compat @r{(C and Objective-C only)}
+Warn about features not present in ISO C23, but present in ISO C2Y.
+For instance, warn about @code{_Generic} selecting with a type name
+instead of an expression. This option is independent of the standards
+mode. Warnings are disabled in the expression that follows
+@code{__extension__}.
+
+When not compiling in C2Y mode, these warnings are upgraded to errors
+by @option{-pedantic-errors}.
+
@opindex Wc++-compat
@opindex Wno-c++-compat
@item -Wc++-compat @r{(C and Objective-C only)}
diff --git a/gcc/doc/standards.texi b/gcc/doc/standards.texi
index 586835b28f31..484fbb10352d 100644
--- a/gcc/doc/standards.texi
+++ b/gcc/doc/standards.texi
@@ -42,6 +42,8 @@ with some exceptions, and possibly with some extensions.
@cindex C23
@cindex ISO C2X
@cindex C2X
+@cindex ISO C2Y
+@cindex C2Y
@cindex Technical Corrigenda
@cindex TC1
@cindex Technical Corrigendum 1
@@ -113,12 +115,16 @@ known as @dfn{C17} and is supported with
@option{-std=c17} or
@option{-std=c11}, and the only difference between the options is the
value of @code{__STDC_VERSION__}.
-A further version of the C standard, known as @dfn{C23}, is under
+A fifth version of the C standard, known as @dfn{C23}, is under
development and expected to be published in 2024 as ISO/IEC 9899:2024.
(While in development, drafts of this standard version were referred
to as @dfn{C2X}.) Experimental and incomplete support for this is
enabled with @option{-std=c23} or @option{-std=iso9899:2024}.
+A further version of the C standard, known as @dfn{C2Y}, is under
+development; experimental and incomplete support for this is enabled
+with @option{-std=c2y}.
+
By default, GCC provides some extensions to the C language that, on
rare occasions conflict with the C standard. @xref{C
Extensions,,Extensions to the C Language Family}.
diff --git a/gcc/dwarf2out.cc b/gcc/dwarf2out.cc
index f90f7b1cfef2..18256843a4c5 100644
--- a/gcc/dwarf2out.cc
+++ b/gcc/dwarf2out.cc
@@ -25281,6 +25281,8 @@ highest_c_language (const char *lang1, const char
*lang2)
if (strcmp ("GNU C++98", lang1) == 0 || strcmp ("GNU C++98", lang2) == 0)
return "GNU C++98";
+ if (strcmp ("GNU C2Y", lang1) == 0 || strcmp ("GNU C2Y", lang2) == 0)
+ return "GNU C2Y";
if (strcmp ("GNU C23", lang1) == 0 || strcmp ("GNU C23", lang2) == 0)
return "GNU C23";
if (strcmp ("GNU C17", lang1) == 0 || strcmp ("GNU C17", lang2) == 0)
@@ -25363,7 +25365,8 @@ gen_compile_unit_die (const char *filename)
if (dwarf_version >= 5 /* || !dwarf_strict */)
if (strcmp (language_string, "GNU C11") == 0
|| strcmp (language_string, "GNU C17") == 0
- || strcmp (language_string, "GNU C23") == 0)
+ || strcmp (language_string, "GNU C23") == 0
+ || strcmp (language_string, "GNU C2Y") == 0)
language = DW_LANG_C11;
}
}
diff --git a/gcc/testsuite/gcc.dg/c23-generic-1.c
b/gcc/testsuite/gcc.dg/c23-generic-1.c
new file mode 100644
index 000000000000..26c97fb4a9ee
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c23-generic-1.c
@@ -0,0 +1,17 @@
+/* Test C2Y _Generic features: error with -std=c23 -pedantic-errors. */
+/* { dg-do compile } */
+/* { dg-options "-std=c23 -pedantic-errors" } */
+
+_Static_assert (_Generic (const int, int : 1, const int : 2) == 2); /* {
dg-error "use of type name" } */
+
+_Static_assert (_Generic (void, int : 1, void : 2) == 2); /* { dg-error "use
of type name" } */
+/* { dg-error "incomplete type" "incomplete type" { target *-*-* } .-1 } */
+
+_Static_assert (_Generic (int (), int (*) () : 1, int () : 2) == 2); /* {
dg-error "use of type name" } */
+/* { dg-error "function type" "function type" { target *-*-* } .-1 } */
+
+const int ci;
+
+_Static_assert (_Generic (typeof (ci), const int : 1, int : 2) == 1); /* {
dg-error "use of type name" } */
+
+_Static_assert (_Generic (ci, const int : 1, int : 2) == 2);
diff --git a/gcc/testsuite/gcc.dg/c23-generic-2.c
b/gcc/testsuite/gcc.dg/c23-generic-2.c
new file mode 100644
index 000000000000..eb31d37b092c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c23-generic-2.c
@@ -0,0 +1,17 @@
+/* Test C2Y _Generic features: warning with -std=c23 -pedantic. */
+/* { dg-do compile } */
+/* { dg-options "-std=c23 -pedantic" } */
+
+_Static_assert (_Generic (const int, int : 1, const int : 2) == 2); /* {
dg-warning "use of type name" } */
+
+_Static_assert (_Generic (void, int : 1, void : 2) == 2); /* { dg-warning "use
of type name" } */
+/* { dg-warning "incomplete type" "incomplete type" { target *-*-* } .-1 } */
+
+_Static_assert (_Generic (int (), int (*) () : 1, int () : 2) == 2); /* {
dg-warning "use of type name" } */
+/* { dg-warning "function type" "function type" { target *-*-* } .-1 } */
+
+const int ci;
+
+_Static_assert (_Generic (typeof (ci), const int : 1, int : 2) == 1); /* {
dg-warning "use of type name" } */
+
+_Static_assert (_Generic (ci, const int : 1, int : 2) == 2);
diff --git a/gcc/testsuite/gcc.dg/c23-generic-3.c
b/gcc/testsuite/gcc.dg/c23-generic-3.c
new file mode 100644
index 000000000000..adf4b3549fff
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c23-generic-3.c
@@ -0,0 +1,16 @@
+/* Test C2Y _Generic features: no warning or error with -std=c23
+ -pedantic-errors -Wno-c23-c2y-compat. */
+/* { dg-do compile } */
+/* { dg-options "-std=c23 -pedantic-errors -Wno-c23-c2y-compat" } */
+
+_Static_assert (_Generic (const int, int : 1, const int : 2) == 2);
+
+_Static_assert (_Generic (void, int : 1, void : 2) == 2);
+
+_Static_assert (_Generic (int (), int (*) () : 1, int () : 2) == 2);
+
+const int ci;
+
+_Static_assert (_Generic (typeof (ci), const int : 1, int : 2) == 1);
+
+_Static_assert (_Generic (ci, const int : 1, int : 2) == 2);
diff --git a/gcc/testsuite/gcc.dg/c23-generic-4.c
b/gcc/testsuite/gcc.dg/c23-generic-4.c
new file mode 100644
index 000000000000..f9f65615dd98
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c23-generic-4.c
@@ -0,0 +1,16 @@
+/* Test C2Y _Generic features: no warning or error with -std=c23 by
+ default. */
+/* { dg-do compile } */
+/* { dg-options "-std=c23" } */
+
+_Static_assert (_Generic (const int, int : 1, const int : 2) == 2);
+
+_Static_assert (_Generic (void, int : 1, void : 2) == 2);
+
+_Static_assert (_Generic (int (), int (*) () : 1, int () : 2) == 2);
+
+const int ci;
+
+_Static_assert (_Generic (typeof (ci), const int : 1, int : 2) == 1);
+
+_Static_assert (_Generic (ci, const int : 1, int : 2) == 2);
diff --git a/gcc/testsuite/gcc.dg/c23-tag-6.c b/gcc/testsuite/gcc.dg/c23-tag-6.c
index 1b65ed3e35d4..7a81487c6e44 100644
--- a/gcc/testsuite/gcc.dg/c23-tag-6.c
+++ b/gcc/testsuite/gcc.dg/c23-tag-6.c
@@ -1,6 +1,6 @@
/*
* { dg-do compile }
- * { dg-options "-std=c23" }
+ * { dg-options "-std=c23 -pedantic-errors" }
*/
// (in-)completeness
diff --git a/gcc/testsuite/gcc.dg/c2y-generic-1.c
b/gcc/testsuite/gcc.dg/c2y-generic-1.c
new file mode 100644
index 000000000000..afb46df99fe4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2y-generic-1.c
@@ -0,0 +1,15 @@
+/* Test C2Y _Generic features. */
+/* { dg-do compile } */
+/* { dg-options "-std=c2y -pedantic-errors" } */
+
+_Static_assert (_Generic (const int, int : 1, const int : 2) == 2);
+
+_Static_assert (_Generic (void, int : 1, void : 2) == 2);
+
+_Static_assert (_Generic (int (), int (*) () : 1, int () : 2) == 2);
+
+const int ci;
+
+_Static_assert (_Generic (typeof (ci), const int : 1, int : 2) == 1);
+
+_Static_assert (_Generic (ci, const int : 1, int : 2) == 2);
diff --git a/gcc/testsuite/gcc.dg/c2y-generic-2.c
b/gcc/testsuite/gcc.dg/c2y-generic-2.c
new file mode 100644
index 000000000000..c37fcc1283b9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2y-generic-2.c
@@ -0,0 +1,17 @@
+/* Test C2Y _Generic features: warning with -Wc23-c2y-compat. */
+/* { dg-do compile } */
+/* { dg-options "-std=c2y -pedantic-errors -Wc23-c2y-compat" } */
+
+_Static_assert (_Generic (const int, int : 1, const int : 2) == 2); /* {
dg-warning "use of type name" } */
+
+_Static_assert (_Generic (void, int : 1, void : 2) == 2); /* { dg-warning "use
of type name" } */
+/* { dg-warning "incomplete type" "incomplete type" { target *-*-* } .-1 } */
+
+_Static_assert (_Generic (int (), int (*) () : 1, int () : 2) == 2); /* {
dg-warning "use of type name" } */
+/* { dg-warning "function type" "function type" { target *-*-* } .-1 } */
+
+const int ci;
+
+_Static_assert (_Generic (typeof (ci), const int : 1, int : 2) == 1); /* {
dg-warning "use of type name" } */
+
+_Static_assert (_Generic (ci, const int : 1, int : 2) == 2);
diff --git a/gcc/testsuite/gcc.dg/c2y-generic-3.c
b/gcc/testsuite/gcc.dg/c2y-generic-3.c
new file mode 100644
index 000000000000..09174fdb095d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2y-generic-3.c
@@ -0,0 +1,9 @@
+/* Test C2Y _Generic features: VM types still not allowed. */
+/* { dg-do compile } */
+/* { dg-options "-std=c2y -pedantic-errors" } */
+
+void
+f (int i)
+{
+ (void) _Generic (i, int : 1, int (*)[i] : 2); /* { dg-error "variable
length" } */
+}
diff --git a/gcc/testsuite/gcc.dg/gnu2y-generic-1.c
b/gcc/testsuite/gcc.dg/gnu2y-generic-1.c
new file mode 100644
index 000000000000..98868ad51d1c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gnu2y-generic-1.c
@@ -0,0 +1,15 @@
+/* Test C2Y _Generic features: __extension__ suppresses -Wc23-c2y-compat
+ warnings (and the state is restored after __extension__). */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu2y -pedantic-errors -Wc23-c2y-compat" } */
+
+_Static_assert (__extension__ _Generic (const int, int : 1, const int : 2) ==
2);
+_Static_assert (_Generic (const int, int : 1, const int : 2) == 2); /* {
dg-warning "use of type name" } */
+
+_Static_assert (__extension__ _Generic (void, int : 1, void : 2) == 2);
+_Static_assert (_Generic (void, int : 1, void : 2) == 2); /* { dg-warning "use
of type name" } */
+/* { dg-warning "incomplete type" "incomplete type" { target *-*-* } .-1 } */
+
+_Static_assert (__extension__ _Generic (int (), int (*) () : 1, int () : 2) ==
2);
+_Static_assert (_Generic (int (), int (*) () : 1, int () : 2) == 2); /* {
dg-warning "use of type name" } */
+/* { dg-warning "function type" "function type" { target *-*-* } .-1 } */
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index c62374d31929..d76817c94fc4 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -172,8 +172,9 @@ enum cpp_ttype
/* C language kind, used when calling cpp_create_reader. */
enum c_lang {CLK_GNUC89 = 0, CLK_GNUC99, CLK_GNUC11, CLK_GNUC17, CLK_GNUC23,
+ CLK_GNUC2Y,
CLK_STDC89, CLK_STDC94, CLK_STDC99, CLK_STDC11, CLK_STDC17,
- CLK_STDC23,
+ CLK_STDC23, CLK_STDC2Y,
CLK_GNUCXX, CLK_CXX98, CLK_GNUCXX11, CLK_CXX11,
CLK_GNUCXX14, CLK_CXX14, CLK_GNUCXX17, CLK_CXX17,
CLK_GNUCXX20, CLK_CXX20, CLK_GNUCXX23, CLK_CXX23,
diff --git a/libcpp/init.cc b/libcpp/init.cc
index c457fa659e7b..9ae06a9595d9 100644
--- a/libcpp/init.cc
+++ b/libcpp/init.cc
@@ -109,12 +109,14 @@ static const struct lang_flags lang_defaults[] =
/* GNUC11 */ { 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0,
0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0 },
/* GNUC17 */ { 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0,
0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0 },
/* GNUC23 */ { 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1,
1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1 },
+ /* GNUC2Y */ { 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1,
1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1 },
/* STDC89 */ { 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0,
0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC94 */ { 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC99 */ { 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0,
0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC11 */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0,
0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC17 */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0,
0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC23 */ { 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1,
1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1 },
+ /* STDC2Y */ { 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1,
1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1 },
/* GNUCXX */ { 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0,
0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1 },
/* CXX98 */ { 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0,
0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1 },
/* GNUCXX11 */ { 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0,
0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1 },
@@ -595,6 +597,9 @@ cpp_init_builtins (cpp_reader *pfile, int hosted)
else if (CPP_OPTION (pfile, lang) == CLK_STDC23
|| CPP_OPTION (pfile, lang) == CLK_GNUC23)
_cpp_define_builtin (pfile, "__STDC_VERSION__ 202311L");
+ else if (CPP_OPTION (pfile, lang) == CLK_STDC2Y
+ || CPP_OPTION (pfile, lang) == CLK_GNUC2Y)
+ _cpp_define_builtin (pfile, "__STDC_VERSION__ 202500L");
else if (CPP_OPTION (pfile, lang) == CLK_STDC17
|| CPP_OPTION (pfile, lang) == CLK_GNUC17)
_cpp_define_builtin (pfile, "__STDC_VERSION__ 201710L");
