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Update from gnulib
This incorporates: 2018-08-05 Fix link error regarding 'rpl_environ' * build-aux/config.guess, lib/unistd.in.h, lib/warn-on-use.h: * m4/extern-inline.m4: Copy from Gnulib.
This commit is contained in:
Paul Eggert
parent
56683b139b
commit
ba8eb994f8
4
build-aux/config.guess
vendored
4
build-aux/config.guess
vendored
@ -2,7 +2,7 @@
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# Attempt to guess a canonical system name.
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# Copyright 1992-2018 Free Software Foundation, Inc.
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timestamp='2018-07-18'
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timestamp='2018-08-02'
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# This file is free software; you can redistribute it and/or modify it
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# under the terms of the GNU General Public License as published by
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@ -126,7 +126,7 @@ set_cc_for_build() {
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# This is needed to find uname on a Pyramid OSx when run in the BSD universe.
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# (ghazi@noc.rutgers.edu 1994-08-24)
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if (test -f /.attbin/uname) >/dev/null 2>&1 ; then
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if test -f /.attbin/uname ; then
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PATH=$PATH:/.attbin ; export PATH
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fi
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@ -432,12 +432,12 @@ extern char **environ;
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#elif defined GNULIB_POSIXCHECK
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# if HAVE_RAW_DECL_ENVIRON
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_GL_UNISTD_INLINE char ***
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_GL_WARN_ON_USE_ATTRIBUTE ("environ is unportable - "
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"use gnulib module environ for portability")
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rpl_environ (void)
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{
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return &environ;
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}
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_GL_WARN_ON_USE (rpl_environ, "environ is unportable - "
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"use gnulib module environ for portability");
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# undef environ
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# define environ (*rpl_environ ())
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# endif
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@ -20,23 +20,32 @@
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supported by the compiler. If the compiler does not support this
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feature, the macro expands to an unused extern declaration.
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This macro is useful for marking a function as a potential
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_GL_WARN_ON_USE_ATTRIBUTE ("literal string") expands to the
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attribute used in _GL_WARN_ON_USE. If the compiler does not support
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this feature, it expands to empty.
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These macros are useful for marking a function as a potential
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portability trap, with the intent that "literal string" include
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instructions on the replacement function that should be used
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instead. However, one of the reasons that a function is a
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portability trap is if it has the wrong signature. Declaring
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FUNCTION with a different signature in C is a compilation error, so
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this macro must use the same type as any existing declaration so
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that programs that avoid the problematic FUNCTION do not fail to
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compile merely because they included a header that poisoned the
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function. But this implies that _GL_WARN_ON_USE is only safe to
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use if FUNCTION is known to already have a declaration. Use of
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this macro implies that there must not be any other macro hiding
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the declaration of FUNCTION; but undefining FUNCTION first is part
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of the poisoning process anyway (although for symbols that are
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provided only via a macro, the result is a compilation error rather
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than a warning containing "literal string"). Also note that in
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C++, it is only safe to use if FUNCTION has no overloads.
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instead.
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_GL_WARN_ON_USE is for functions with 'extern' linkage.
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_GL_WARN_ON_USE_ATTRIBUTE is for functions with 'static' or 'inline'
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linkage.
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However, one of the reasons that a function is a portability trap is
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if it has the wrong signature. Declaring FUNCTION with a different
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signature in C is a compilation error, so this macro must use the
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same type as any existing declaration so that programs that avoid
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the problematic FUNCTION do not fail to compile merely because they
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included a header that poisoned the function. But this implies that
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_GL_WARN_ON_USE is only safe to use if FUNCTION is known to already
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have a declaration. Use of this macro implies that there must not
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be any other macro hiding the declaration of FUNCTION; but
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undefining FUNCTION first is part of the poisoning process anyway
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(although for symbols that are provided only via a macro, the result
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is a compilation error rather than a warning containing
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"literal string"). Also note that in C++, it is only safe to use if
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FUNCTION has no overloads.
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For an example, it is possible to poison 'getline' by:
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- adding a call to gl_WARN_ON_USE_PREPARE([[#include <stdio.h>]],
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@ -54,12 +63,21 @@
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(less common usage, like &environ, will cause a compilation error
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rather than issue the nice warning, but the end result of informing
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the developer about their portability problem is still achieved):
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#if HAVE_RAW_DECL_ENVIRON
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static char ***rpl_environ (void) { return &environ; }
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_GL_WARN_ON_USE (rpl_environ, "environ is not always properly declared");
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# undef environ
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# define environ (*rpl_environ ())
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#endif
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#if HAVE_RAW_DECL_ENVIRON
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static char ***
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rpl_environ (void) { return &environ; }
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_GL_WARN_ON_USE (rpl_environ, "environ is not always properly declared");
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# undef environ
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# define environ (*rpl_environ ())
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#endif
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or better (avoiding contradictory use of 'static' and 'extern'):
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#if HAVE_RAW_DECL_ENVIRON
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static char ***
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_GL_WARN_ON_USE_ATTRIBUTE ("environ is not always properly declared")
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rpl_environ (void) { return &environ; }
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# undef environ
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# define environ (*rpl_environ ())
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#endif
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*/
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#ifndef _GL_WARN_ON_USE
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@ -67,13 +85,17 @@
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/* A compiler attribute is available in gcc versions 4.3.0 and later. */
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# define _GL_WARN_ON_USE(function, message) \
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extern __typeof__ (function) function __attribute__ ((__warning__ (message)))
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# define _GL_WARN_ON_USE_ATTRIBUTE(message) \
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__attribute__ ((__warning__ (message)))
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# elif __GNUC__ >= 3 && GNULIB_STRICT_CHECKING
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/* Verify the existence of the function. */
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# define _GL_WARN_ON_USE(function, message) \
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extern __typeof__ (function) function
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# define _GL_WARN_ON_USE_ATTRIBUTE(message)
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# else /* Unsupported. */
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# define _GL_WARN_ON_USE(function, message) \
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_GL_WARN_EXTERN_C int _gl_warn_on_use
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# define _GL_WARN_ON_USE_ATTRIBUTE(message)
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# endif
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#endif
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@ -25,7 +25,8 @@ AC_DEFUN([gl_EXTERN_INLINE],
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if isdigit is mistakenly implemented via a static inline function,
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a program containing an extern inline function that calls isdigit
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may not work since the C standard prohibits extern inline functions
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from calling static functions. This bug is known to occur on:
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from calling static functions (ISO C 99 section 6.7.4.(3).
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This bug is known to occur on:
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OS X 10.8 and earlier; see:
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https://lists.gnu.org/r/bug-gnulib/2012-12/msg00023.html
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@ -38,7 +39,18 @@ AC_DEFUN([gl_EXTERN_INLINE],
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OS X 10.9 has a macro __header_inline indicating the bug is fixed for C and
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for clang but remains for g++; see <https://trac.macports.org/ticket/41033>.
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Assume DragonFly and FreeBSD will be similar. */
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Assume DragonFly and FreeBSD will be similar.
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GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
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inline semantics, unless -fgnu89-inline is used. It defines a macro
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__GNUC_STDC_INLINE__ to indicate this situation or a macro
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__GNUC_GNU_INLINE__ to indicate the opposite situation.
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GCC 4.2 with -std=c99 or -std=gnu99 implements the GNU C inline
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semantics but warns, unless -fgnu89-inline is used:
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warning: C99 inline functions are not supported; using GNU89
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warning: to disable this warning use -fgnu89-inline or the gnu_inline function attribute
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It defines a macro __GNUC_GNU_INLINE__ to indicate this situation.
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*/
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#if (((defined __APPLE__ && defined __MACH__) \
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|| defined __DragonFly__ || defined __FreeBSD__) \
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&& (defined __header_inline \
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