view m4/c-strtod.m4 @ 9600:99268e709d31

Avoid quadratic strstr implementations. * lib/strstr.c: New file. * m4/strstr.m4: Likewise. * modules/strstr: Likewise. * modules/strstr-tests: Likewise. * tests/test-strstr.c: Likewise. * lib/string.in.h (rpl_strstr): Declare. (memmem) [GNULIB_POSIXCHECK]: Document speed issue. * m4/string_h.m4 (gl_HEADER_STRING_H_DEFAULTS): Support strstr. * modules/string (Makefile.am): Likewise. * MODULES.html.sh (string handling): Mention new module. * doc/functions/strstr.texi (strstr): Document the bug. Signed-off-by: Eric Blake <ebb9@byu.net>
author Eric Blake <ebb9@byu.net>
date Thu, 10 Jan 2008 07:38:11 -0700
parents be9e01d008cb
children f6cba5a556ce
line wrap: on
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# c-strtod.m4 serial 9

# Copyright (C) 2004, 2005, 2006 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.

# Written by Paul Eggert.

AC_DEFUN([gl_C99_STRTOLD],
[
  AC_CACHE_CHECK([whether strtold conforms to C99],
    [gl_cv_func_c99_strtold],
    [AC_LINK_IFELSE(
       [AC_LANG_PROGRAM(
          [[/* On HP-UX before 11.23, strtold returns a struct instead of
		long double.  Reject implementations like that, by requiring
		compatibility with the C99 prototype.  */
	     #include <stdlib.h>
	     static long double (*p) (char const *, char **) = strtold;
	     static long double
	     test (char const *nptr, char **endptr)
	     {
	       long double r;
	       r = strtold (nptr, endptr);
	       return r;
	     }]],
           [[return test ("1.0", NULL) != 1 || p ("1.0", NULL) != 1;]])],
       [gl_cv_func_c99_strtold=yes],
       [gl_cv_func_c99_strtold=no])])
  if test $gl_cv_func_c99_strtold = yes; then
    AC_DEFINE([HAVE_C99_STRTOLD], 1, [Define to 1 if strtold conforms to C99.])
  fi
])

AC_DEFUN([gl_C_STRTOD],
[
  AC_LIBOBJ([c-strtod])

  dnl Prerequisites of lib/c-strtod.c.
  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
  :
])

AC_DEFUN([gl_C_STRTOLD],
[
  AC_LIBOBJ([c-strtold])

  dnl Prerequisites of lib/c-strtold.c.
  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
  AC_REQUIRE([gl_C99_STRTOLD])
  :
])