From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org
Subject: [PATCH 1/5] misc: Sync cdefs.h with gnulib
Date: Wed, 13 Jan 2021 13:58:22 -0300 [thread overview]
Message-ID: <20210113165826.1014708-1-adhemerval.zanella@linaro.org> (raw)
It adds __glibc_has_builtin, __glibc_has_extension, and
__attribute_maybe_unused__ alongsize with some fixes.
The only difference is:
--- ../../gnulib/gnulib-lib/lib/cdefs.h 2021-01-08 17:10:32.683471041 -0300
+++ misc/sys/cdefs.h 2021-01-13 13:34:46.409398805 -0300
@@ -483,7 +483,7 @@
/* The #ifndef lets Gnulib avoid including these on non-glibc
platforms, where the includes typically do not exist. */
-#ifndef __WORDSIZE
+#ifdef __GLIBC__
# include <bits/wordsize.h>
# include <bits/long-double.h>
#endif
Where __WORDSIZE does not play well with internal cdefs.h that also
uses __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI.
Checked on x86_64-linux-gnu.
---
misc/sys/cdefs.h | 142 ++++++++++++++++++++++++++++-------------------
1 file changed, 84 insertions(+), 58 deletions(-)
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index 57ca262bdf..12a2f3c249 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -34,7 +34,27 @@
#undef __P
#undef __PMT
-#ifdef __GNUC__
+/* Compilers that lack __has_attribute may object to
+ #if defined __has_attribute && __has_attribute (...)
+ even though they do not need to evaluate the right-hand side of the &&.
+ Similarly for __has_builtin, etc. */
+#ifdef __has_attribute
+# define __glibc_has_attribute(attr) __has_attribute (attr)
+#else
+# define __glibc_has_attribute(attr) 0
+#endif
+#ifdef __has_builtin
+# define __glibc_has_builtin(name) __has_builtin (name)
+#else
+# define __glibc_has_builtin(name) 0
+#endif
+#ifdef __has_extension
+# define __glibc_has_extension(ext) __has_extension (ext)
+#else
+# define __glibc_has_extension(ext) 0
+#endif
+
+#if defined __GNUC__ || defined __clang__
/* All functions, except those with callbacks or those that
synchronize memory, are leaf functions. */
@@ -48,16 +68,17 @@
/* GCC can always grok prototypes. For C++ programs we add throw()
to help it optimize the function calls. But this only works with
- gcc 2.8.x and egcs. For gcc 3.2 and up we even mark C functions
+ gcc 2.8.x and egcs. For gcc 3.4 and up we even mark C functions
as non-throwing using a function attribute since programs can use
the -fexceptions options for C code as well. */
-# if !defined __cplusplus && __GNUC_PREREQ (3, 3)
+# if !defined __cplusplus \
+ && (__GNUC_PREREQ (3, 4) || __glibc_has_attribute (__nothrow__))
# define __THROW __attribute__ ((__nothrow__ __LEAF))
# define __THROWNL __attribute__ ((__nothrow__))
# define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct
# define __NTHNL(fct) __attribute__ ((__nothrow__)) fct
# else
-# if defined __cplusplus && __GNUC_PREREQ (2,8)
+# if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major >= 4)
# if __cplusplus >= 201103L
# define __THROW noexcept (true)
# else
@@ -74,7 +95,7 @@
# endif
# endif
-#else /* Not GCC. */
+#else /* Not GCC or clang. */
# if (defined __cplusplus \
|| (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
@@ -87,16 +108,7 @@
# define __THROWNL
# define __NTH(fct) fct
-#endif /* GCC. */
-
-/* Compilers that are not clang may object to
- #if defined __clang__ && __has_extension(...)
- even though they do not need to evaluate the right-hand side of the &&. */
-#if defined __clang__ && defined __has_extension
-# define __glibc_clang_has_extension(ext) __has_extension (ext)
-#else
-# define __glibc_clang_has_extension(ext) 0
-#endif
+#endif /* GCC || clang. */
/* These two macros are not used in glibc anymore. They are kept here
only because some other projects expect the macros to be defined. */
@@ -149,11 +161,11 @@
Headers that should use flexible arrays only if they're "real"
(e.g. only if they won't affect sizeof()) should test
#if __glibc_c99_flexarr_available. */
-#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
+#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
# define __flexarr []
# define __glibc_c99_flexarr_available 1
-#elif __GNUC_PREREQ (2,97)
-/* GCC 2.97 supports C99 flexible array members as an extension,
+#elif __GNUC_PREREQ (2,97) || defined __clang__
+/* GCC 2.97 and clang support C99 flexible array members as an extension,
even when in C89 mode or compiling C++ (any version). */
# define __flexarr []
# define __glibc_c99_flexarr_available 1
@@ -179,7 +191,7 @@
Example:
int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
-#if defined __GNUC__ && __GNUC__ >= 2
+#if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4)
# define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
# ifdef __cplusplus
@@ -204,17 +216,17 @@
*/
#endif
-/* GCC has various useful declarations that can be made with the
- `__attribute__' syntax. All of the ways we use this do fine if
- they are omitted for compilers that don't understand it. */
-#if !defined __GNUC__ || __GNUC__ < 2
+/* GCC and clang have various useful declarations that can be made with
+ the '__attribute__' syntax. All of the ways we use this do fine if
+ they are omitted for compilers that don't understand it. */
+#if !(defined __GNUC__ || defined __clang__)
# define __attribute__(xyz) /* Ignore */
#endif
/* At some point during the gcc 2.96 development the `malloc' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings. */
-#if __GNUC_PREREQ (2,96)
+#if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__)
# define __attribute_malloc__ __attribute__ ((__malloc__))
#else
# define __attribute_malloc__ /* Ignore */
@@ -232,23 +244,31 @@
/* At some point during the gcc 2.96 development the `pure' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings. */
-#if __GNUC_PREREQ (2,96)
+#if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__)
# define __attribute_pure__ __attribute__ ((__pure__))
#else
# define __attribute_pure__ /* Ignore */
#endif
/* This declaration tells the compiler that the value is constant. */
-#if __GNUC_PREREQ (2,5)
+#if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__)
# define __attribute_const__ __attribute__ ((__const__))
#else
# define __attribute_const__ /* Ignore */
#endif
+#if defined __STDC_VERSION__ && 201710L < __STDC_VERSION__
+# define __attribute_maybe_unused__ [[__maybe_unused__]]
+#elif __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__)
+# define __attribute_maybe_unused__ __attribute__ ((__unused__))
+#else
+# define __attribute_maybe_unused__ /* Ignore */
+#endif
+
/* At some point during the gcc 3.1 development the `used' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings. */
-#if __GNUC_PREREQ (3,1)
+#if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__)
# define __attribute_used__ __attribute__ ((__used__))
# define __attribute_noinline__ __attribute__ ((__noinline__))
#else
@@ -257,7 +277,7 @@
#endif
/* Since version 3.2, gcc allows marking deprecated functions. */
-#if __GNUC_PREREQ (3,2)
+#if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__)
# define __attribute_deprecated__ __attribute__ ((__deprecated__))
#else
# define __attribute_deprecated__ /* Ignore */
@@ -267,7 +287,7 @@
when a deprecated function is used. clang claims to be gcc 4.2, but
may also support this feature. */
#if __GNUC_PREREQ (4,5) \
- || __glibc_clang_has_extension (__attribute_deprecated_with_message__)
+ || __glibc_has_extension (__attribute_deprecated_with_message__)
# define __attribute_deprecated_msg__(msg) \
__attribute__ ((__deprecated__ (msg)))
#else
@@ -280,7 +300,7 @@
If several `format_arg' attributes are given for the same function, in
gcc-3.0 and older, all but the last one are ignored. In newer gccs,
all designated arguments are considered. */
-#if __GNUC_PREREQ (2,8)
+#if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__)
# define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
#else
# define __attribute_format_arg__(x) /* Ignore */
@@ -290,27 +310,30 @@
attribute for functions was introduced. We don't want to use it
unconditionally (although this would be possible) since it
generates warnings. */
-#if __GNUC_PREREQ (2,97)
+#if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__)
# define __attribute_format_strfmon__(a,b) \
__attribute__ ((__format__ (__strfmon__, a, b)))
#else
# define __attribute_format_strfmon__(a,b) /* Ignore */
#endif
-/* The nonull function attribute allows to mark pointer parameters which
- must not be NULL. */
-#if __GNUC_PREREQ (3,3)
-# define __nonnull(params) __attribute__ ((__nonnull__ params))
-#else
-# define __nonnull(params)
+/* The nonnull function attribute marks pointer parameters that
+ must not be NULL. Do not define __nonnull if it is already defined,
+ for portability when this file is used in Gnulib. */
+#ifndef __nonnull
+# if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__)
+# define __nonnull(params) __attribute__ ((__nonnull__ params))
+# else
+# define __nonnull(params)
+# endif
#endif
/* If fortification mode, we warn about unused results of certain
function calls which can lead to problems. */
-#if __GNUC_PREREQ (3,4)
+#if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__)
# define __attribute_warn_unused_result__ \
__attribute__ ((__warn_unused_result__))
-# if __USE_FORTIFY_LEVEL > 0
+# if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0
# define __wur __attribute_warn_unused_result__
# endif
#else
@@ -321,7 +344,7 @@
#endif
/* Forces a function to be always inlined. */
-#if __GNUC_PREREQ (3,2)
+#if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__)
/* The Linux kernel defines __always_inline in stddef.h (283d7573), and
it conflicts with this definition. Therefore undefine it first to
allow either header to be included first. */
@@ -334,7 +357,7 @@
/* Associate error messages with the source location of the call site rather
than with the source location inside the function. */
-#if __GNUC_PREREQ (4,3)
+#if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__)
# define __attribute_artificial__ __attribute__ ((__artificial__))
#else
# define __attribute_artificial__ /* Ignore */
@@ -377,12 +400,14 @@
run in pedantic mode if the uses are carefully marked using the
`__extension__' keyword. But this is not generally available before
version 2.8. */
-#if !__GNUC_PREREQ (2,8)
+#if !(__GNUC_PREREQ (2,8) || defined __clang__)
# define __extension__ /* Ignore */
#endif
-/* __restrict is known in EGCS 1.2 and above. */
-#if !__GNUC_PREREQ (2,92)
+/* __restrict is known in EGCS 1.2 and above, and in clang.
+ It works also in C++ mode (outside of arrays), but only when spelled
+ as '__restrict', not 'restrict'. */
+#if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3)
# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
# define __restrict restrict
# else
@@ -392,8 +417,9 @@
/* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
array_name[restrict]
- GCC 3.1 supports this. */
-#if __GNUC_PREREQ (3,1) && !defined __GNUG__
+ GCC 3.1 and clang support this.
+ This syntax is not usable in C++ mode. */
+#if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus
# define __restrict_arr __restrict
#else
# ifdef __GNUC__
@@ -408,7 +434,7 @@
# endif
#endif
-#if __GNUC__ >= 3
+#if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect)
# define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
# define __glibc_likely(cond) __builtin_expect ((cond), 1)
#else
@@ -416,15 +442,10 @@
# define __glibc_likely(cond) (cond)
#endif
-#ifdef __has_attribute
-# define __glibc_has_attribute(attr) __has_attribute (attr)
-#else
-# define __glibc_has_attribute(attr) 0
-#endif
-
#if (!defined _Noreturn \
&& (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
- && !__GNUC_PREREQ (4,7))
+ && !(__GNUC_PREREQ (4,7) \
+ || (3 < __clang_major__ + (5 <= __clang_minor__))))
# if __GNUC_PREREQ (2,8)
# define _Noreturn __attribute__ ((__noreturn__))
# else
@@ -453,14 +474,19 @@
#if (!defined _Static_assert && !defined __cplusplus \
&& (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
- && (!__GNUC_PREREQ (4, 6) || defined __STRICT_ANSI__))
+ && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \
+ || defined __STRICT_ANSI__))
# define _Static_assert(expr, diagnostic) \
extern int (*__Static_assert_function (void)) \
[!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
#endif
-#include <bits/wordsize.h>
-#include <bits/long-double.h>
+/* The #ifndef lets Gnulib avoid including these on non-glibc
+ platforms, where the includes typically do not exist. */
+#ifdef __GLIBC__
+# include <bits/wordsize.h>
+# include <bits/long-double.h>
+#endif
#if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
# ifdef __REDIRECT
@@ -550,7 +576,7 @@ _Static_assert (0, "IEEE 128-bits long double requires redirection on this platf
check is required to enable the use of generic selection. */
#if !defined __cplusplus \
&& (__GNUC_PREREQ (4, 9) \
- || __glibc_clang_has_extension (c_generic_selections) \
+ || __glibc_has_extension (c_generic_selections) \
|| (!defined __GNUC__ && defined __STDC_VERSION__ \
&& __STDC_VERSION__ >= 201112L))
# define __HAVE_GENERIC_SELECTION 1
--
2.25.1
next reply other threads:[~2021-01-13 16:58 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-13 16:58 Adhemerval Zanella [this message]
2021-01-13 16:58 ` [PATCH 2/5] malloc: Sync dynarray " Adhemerval Zanella
2021-02-09 19:12 ` Adhemerval Zanella
2021-01-13 16:58 ` [PATCH v2 3/5] regex: remove alloca usage on regex set_regs Adhemerval Zanella
2021-02-09 19:12 ` Adhemerval Zanella
2021-01-13 16:58 ` [PATCH v2 4/5] regexec: remove alloca usage in build_trtable Adhemerval Zanella
2021-02-09 19:12 ` Adhemerval Zanella
2021-01-13 16:58 ` [PATCH v2 5/5] regex: stop using alloca Adhemerval Zanella
2021-02-09 19:12 ` Adhemerval Zanella
2021-01-13 18:09 ` [PATCH 1/5] misc: Sync cdefs.h with gnulib Joseph Myers
2021-01-13 18:30 ` Adhemerval Zanella
2021-02-09 14:07 ` Adhemerval Zanella
2021-01-13 19:19 ` Paul Eggert
2021-01-13 19:21 ` Adhemerval Zanella
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