c: New C2x keywords

C2x follows C++ in making alignas, alignof, bool, false,
static_assert, thread_local and true keywords; implement this
accordingly.  This implementation makes them normal keywords in C2x
mode just like any other keyword (C2x leaves open the possibility of
implementation using predefined macros instead - thus, there aren't
any testcases asserting that they aren't macros).  As in C++ and
previous versions of C, true and false are handled like signed 1 and 0
in #if (there was an intermediate state in some C2x drafts where they
had different macro expansions that were unsigned in #if).

Bootstrapped with no regressions for x86_64-pc-linux-gnu.

As with the removal of unprototyped functions, this change has a high
risk of breaking some old code and people doing GNU/Linux distribution
builds may wish to see how much is broken in a build with a -std=gnu2x
default.

gcc/
	* ginclude/stdalign.h [defined __STDC_VERSION__ &&
	__STDC_VERSION__ > 201710L]: Disable all content.
	* ginclude/stdbool.h [defined __STDC_VERSION__ && __STDC_VERSION__
	> 201710L] (bool, true, false): Do not define.

gcc/c-family/
	* c-common.cc (c_common_reswords): Use D_C2X instead of D_CXXONLY
	for alignas, alignof, bool, false, static_assert, thread_local and
	true.

gcc/c/
	* c-parser.cc (c_parser_static_assert_declaration_no_semi)
	(c_parser_alignas_specifier, c_parser_alignof_expression): Allow
	for C2x spellings of keywords.
	(c_parser_postfix_expression): Handle RID_TRUE and RID_FALSE.

gcc/testsuite/
	* gcc.dg/c11-keywords-1.c, gcc.dg/c2x-align-1.c,
	gcc.dg/c2x-align-6.c, gcc.dg/c2x-bool-2.c,
	gcc.dg/c2x-static-assert-3.c, gcc.dg/c2x-static-assert-4.c,
	gcc.dg/c2x-thread-local-1.c: New tests.
	* gcc.dg/c2x-bool-1.c: Update expectations.

libcpp/
	* include/cpplib.h (struct cpp_options): Add true_false.
	* expr.cc (eval_token): Check true_false not cplusplus to
	determine whether to handle true and false keywords.
	* init.cc (struct lang_flags): Add true_false.
	(lang_defaults): Update.
	(cpp_set_lang): Set true_false.
This commit is contained in:
Joseph Myers
2022-09-07 13:56:25 +00:00
parent 7abcdb06e3
commit 0a91bdaf17
15 changed files with 188 additions and 55 deletions

View File

@@ -98,34 +98,35 @@ struct lang_flags
char elifdef;
char warning_directive;
char delimited_escape_seqs;
char true_false;
};
static const struct lang_flags lang_defaults[] =
{ /* c99 c++ xnum xid c11 std digr ulit rlit udlit bincst digsep trig u8chlit vaopt scope dfp szlit elifdef warndir delim */
/* GNUC89 */ { 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0 },
/* GNUC99 */ { 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0 },
/* GNUC11 */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0 },
/* GNUC17 */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0 },
/* GNUC2X */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 0 },
/* STDC89 */ { 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC94 */ { 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC99 */ { 1, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC11 */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC17 */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC2X */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0 },
/* GNUCXX */ { 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0 },
/* CXX98 */ { 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0 },
/* GNUCXX11 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0 },
/* CXX11 */ { 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0 },
/* GNUCXX14 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0 },
/* CXX14 */ { 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0 },
/* GNUCXX17 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0 },
/* CXX17 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0 },
/* GNUCXX20 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0 },
/* CXX20 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0 },
/* GNUCXX23 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1 },
/* CXX23 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1 },
/* ASM */ { 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
{ /* c99 c++ xnum xid c11 std digr ulit rlit udlit bincst digsep trig u8chlit vaopt scope dfp szlit elifdef warndir delim trufal */
/* GNUC89 */ { 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0 },
/* GNUC99 */ { 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0 },
/* GNUC11 */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0 },
/* GNUC17 */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0 },
/* GNUC2X */ { 1, 0, 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, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC94 */ { 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, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC11 */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC17 */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
/* STDC2X */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1 },
/* GNUCXX */ { 0, 1, 1, 1, 0, 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, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1 },
/* GNUCXX11 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1 },
/* CXX11 */ { 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1 },
/* GNUCXX14 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1 },
/* CXX14 */ { 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1 },
/* GNUCXX17 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1 },
/* CXX17 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1 },
/* GNUCXX20 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1 },
/* CXX20 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1 },
/* GNUCXX23 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1 },
/* CXX23 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1 },
/* ASM */ { 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};
/* Sets internal flags correctly for a given language. */
@@ -157,6 +158,7 @@ cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
CPP_OPTION (pfile, elifdef) = l->elifdef;
CPP_OPTION (pfile, warning_directive) = l->warning_directive;
CPP_OPTION (pfile, delimited_escape_seqs) = l->delimited_escape_seqs;
CPP_OPTION (pfile, true_false) = l->true_false;
}
/* Initialize library global state. */