kc3-lang/gnulib/m4/time_r.m4

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• Hash : 32a72f45
  Author :
  Date : 2023-01-01T01:14:21
  

  maint: run 'make update-copyright'
  

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• m4/time_r.m4

• dnl Reentrant time functions: localtime_r, gmtime_r.
  
  dnl Copyright (C) 2003, 2006-2023 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
  dnl with or without modifications, as long as this notice is preserved.
  
  dnl Written by Paul Eggert.
  
  AC_DEFUN([gl_TIME_R],
  [
    dnl Persuade glibc and Solaris <time.h> to declare localtime_r.
    AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
  
    AC_REQUIRE([gl_TIME_H_DEFAULTS])
    AC_REQUIRE([AC_C_RESTRICT])
  
    dnl Some systems don't declare localtime_r() and gmtime_r() if _REENTRANT is
    dnl not defined.
    AC_CHECK_DECLS([localtime_r], [], [],
      [[/* mingw's <time.h> provides the functions asctime_r, ctime_r,
           gmtime_r, localtime_r only if <unistd.h> or <pthread.h> has
           been included before.  */
        #if defined __MINGW32__
        # include <unistd.h>
        #endif
        #include <time.h>
      ]])
    if test $ac_cv_have_decl_localtime_r = no; then
      HAVE_DECL_LOCALTIME_R=0
    fi
  
    AC_CHECK_FUNCS_ONCE([localtime_r])
    if test $ac_cv_func_localtime_r = yes; then
      HAVE_LOCALTIME_R=1
      AC_CACHE_CHECK([whether localtime_r is compatible with its POSIX signature],
        [gl_cv_time_r_posix],
        [AC_COMPILE_IFELSE(
           [AC_LANG_PROGRAM(
              [[/* mingw's <time.h> provides the functions asctime_r, ctime_r,
                   gmtime_r, localtime_r only if <unistd.h> or <pthread.h> has
                   been included before.  */
                #if defined __MINGW32__
                # include <unistd.h>
                #endif
                #include <time.h>
              ]],
              [[/* We don't need to append 'restrict's to the argument types,
                   even though the POSIX signature has the 'restrict's,
                   since C99 says they can't affect type compatibility.  */
                struct tm * (*ptr) (time_t const *, struct tm *) = localtime_r;
                if (ptr) return 0;
                /* Check the return type is a pointer.
                   On HP-UX 10 it is 'int'.  */
                *localtime_r (0, 0);]])
           ],
           [gl_cv_time_r_posix=yes],
           [gl_cv_time_r_posix=no])
        ])
      if test $gl_cv_time_r_posix = yes; then
        REPLACE_LOCALTIME_R=0
      else
        REPLACE_LOCALTIME_R=1
      fi
    else
      HAVE_LOCALTIME_R=0
      dnl On mingw, localtime_r() is defined as an inline function; use through a
      dnl direct function call works but the use as a function pointer leads to a
      dnl link error.
      AC_CACHE_CHECK([whether localtime_r exists as an inline function],
        [gl_cv_func_localtime_r_inline],
        [AC_LINK_IFELSE(
           [AC_LANG_PROGRAM(
              [[/* mingw's <time.h> provides the functions asctime_r, ctime_r,
                   gmtime_r, localtime_r only if <unistd.h> or <pthread.h> has
                   been included before.  */
                #if defined __MINGW32__
                # include <unistd.h>
                #endif
                #include <time.h>
              ]],
              [[time_t a;
                struct tm r;
                localtime_r (&a, &r);
              ]])
           ],
           [gl_cv_func_localtime_r_inline=yes],
           [gl_cv_func_localtime_r_inline=no])
        ])
      if test $gl_cv_func_localtime_r_inline = yes; then
        REPLACE_LOCALTIME_R=1
      fi
    fi
  ])
  
  # Prerequisites of lib/time_r.c.
  AC_DEFUN([gl_PREREQ_TIME_R], [
    :
  ])
  

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