Mercurial > gnulib
view m4/fflush.m4 @ 40140:81f075eaa990
ptsname_r: Work around bug on Android 4.3.
* m4/ptsname_r.m4 (gl_FUNC_PTSNAME_R): Define
HAVE_ESSENTIALLY_WORKING_PTSNAME_R. Test whether the return value is
correct.
* lib/ptsname_r.c (__ptsname_r): If HAVE_ESSENTIALLY_WORKING_PTSNAME_R
is defined, just fix the return value.
* doc/glibc-functions/ptsname_r.texi: Mention the Android bug. Reword:
The behaviour of musl libc is nothing to be "fixed", since it is
compliant with the next POSIX standard.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Sat, 26 Jan 2019 15:23:19 +0100 |
parents | b06060465f09 |
children |
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# fflush.m4 serial 17 # Copyright (C) 2007-2019 Free Software Foundation, Inc. # This file is free software; the Free Software Foundation # gives unlimited permission to copy and/or distribute it, # with or without modifications, as long as this notice is preserved. dnl From Eric Blake dnl Find out how to obey POSIX semantics of fflush(stdin) discarding dnl unread input on seekable streams, rather than C99 undefined semantics. AC_DEFUN([gl_FUNC_FFLUSH], [ AC_REQUIRE([gl_STDIO_H_DEFAULTS]) gl_FUNC_FFLUSH_STDIN case "$gl_cv_func_fflush_stdin" in *yes) ;; *) REPLACE_FFLUSH=1 ;; esac ]) dnl Determine whether fflush works on input streams. dnl Sets gl_cv_func_fflush_stdin. AC_DEFUN([gl_FUNC_FFLUSH_STDIN], [ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CHECK_HEADERS_ONCE([unistd.h]) AC_CACHE_CHECK([whether fflush works on input streams], [gl_cv_func_fflush_stdin], [echo hello world > conftest.txt AC_RUN_IFELSE([AC_LANG_PROGRAM( [[ #include <stdio.h> #if HAVE_UNISTD_H # include <unistd.h> #else /* on Windows with MSVC */ # include <io.h> #endif ]], [[FILE *f = fopen ("conftest.txt", "r"); char buffer[10]; int fd; int c; if (f == NULL) return 1; fd = fileno (f); if (fd < 0 || fread (buffer, 1, 5, f) != 5) { fclose (f); return 2; } /* For deterministic results, ensure f read a bigger buffer. */ if (lseek (fd, 0, SEEK_CUR) == 5) { fclose (f); return 3; } /* POSIX requires fflush-fseek to set file offset of fd. This fails on BSD systems and on mingw. */ if (fflush (f) != 0 || fseek (f, 0, SEEK_CUR) != 0) { fclose (f); return 4; } if (lseek (fd, 0, SEEK_CUR) != 5) { fclose (f); return 5; } /* Verify behaviour of fflush after ungetc. See <http://www.opengroup.org/austin/aardvark/latest/xshbug3.txt> */ /* Verify behaviour of fflush after a backup ungetc. This fails on mingw. */ c = fgetc (f); ungetc (c, f); fflush (f); if (fgetc (f) != c) { fclose (f); return 6; } /* Verify behaviour of fflush after a non-backup ungetc. This fails on glibc 2.8 and on BSD systems. */ c = fgetc (f); ungetc ('@', f); fflush (f); if (fgetc (f) != c) { fclose (f); return 7; } fclose (f); return 0; ]])], [gl_cv_func_fflush_stdin=yes], [gl_cv_func_fflush_stdin=no], [case "$host_os" in # Guess no on native Windows. mingw*) gl_cv_func_fflush_stdin="guessing no" ;; *) gl_cv_func_fflush_stdin=cross ;; esac ]) rm conftest.txt ]) case "$gl_cv_func_fflush_stdin" in *yes) gl_func_fflush_stdin=1 ;; *no) gl_func_fflush_stdin=0 ;; *) gl_func_fflush_stdin='(-1)' ;; esac AC_DEFINE_UNQUOTED([FUNC_FFLUSH_STDIN], [$gl_func_fflush_stdin], [Define to 1 if fflush is known to work on stdin as per POSIX.1-2008, 0 if fflush is known to not work, -1 if unknown.]) ]) # Prerequisites of lib/fflush.c. AC_DEFUN([gl_PREREQ_FFLUSH], [:])