mirror/autoconf
2
0
Fork 0
mirror of git://git.sv.gnu.org/autoconf synced 2025-02-23 14:09:51 +08:00
Code Issues Packages Projects Releases Wiki Activity

No longer use CPP to check for the existing of headers: use CC to

Browse Source 
check for compilability.

(_AC_CHECK_HEADER_MONGREL, AC_CHECK_HEADER, _AC_CHECK_HEADER_OLD): Remove.
(_AC_CHECK_HEADER_NEW): Rename as...
(AC_CHECK_HEADER): this.
This commit is contained in:
Paul Eggert 2002-10-11 23:52:06 +00:00
parent 1b8a4459ee
commit 7006b6880c
1 changed files with 4 additions and 94 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

98
lib/autoconf/headers.m4
View File

@ -1,7 +1,7 @@
# This file is part of Autoconf. -*- Autoconf -*-
# Checking for headers.
# Copyright 2000, 2001
# Free Software Foundation, Inc.
#
# Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
@ -67,83 +67,8 @@
# [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND],
# [INCLUDES])
# ---------------------------------------------------------
# We are slowly moving to checking headers with the compiler instead
# of the preproc, so that we actually learn about the usability of a
# header instead of its mere presence. But since users are used to
# the old semantics, they check for headers in random order and
# without providing prerequisite headers. This macro implements the
# transition phase, and should be cleaned up latter to use compilation
# only.
#
# If INCLUDES is empty, then check both via the compiler and preproc.
# If the results are different, issue a warning, but keep the preproc
# result.
#
# If INCLUDES is `-', keep only the old semantics.
#
# If INCLUDES is specified and different from `-', then use the new
# semantics only.
AC_DEFUN([AC_CHECK_HEADER],
[m4_case([$4],
[], [_AC_CHECK_HEADER_MONGREL($@)],
[-], [_AC_CHECK_HEADER_OLD($@)],
[_AC_CHECK_HEADER_NEW($@)])
])# AC_CHECK_HEADER
# _AC_CHECK_HEADER_MONGREL(HEADER-FILE,
# [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND],
# [INCLUDES])
# --------------------------------------------------------------
# Check using both the compiler and the preprocessor. If they disagree,
# warn, and the preproc wins.
#
# This is not based on _AC_CHECK_HEADER_NEW and _AC_CHECK_HEADER_OLD
# because it obfuscate the code to try to factor everything, in particular
# because of the cache variables, and the `checking...' messages.
m4_define([_AC_CHECK_HEADER_MONGREL],
[AS_VAR_PUSHDEF([ac_Header], [ac_cv_header_$1])dnl
AS_VAR_SET_IF(ac_Header,
[AC_CACHE_CHECK([for $1], ac_Header, [])],
[# Is the header compilable?
AC_MSG_CHECKING([$1 usability])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([AC_INCLUDES_DEFAULT([$4])
@%:@include <$1>])],
[ac_header_compiler=yes],
[ac_header_compiler=no])
AC_MSG_RESULT([$ac_header_compiler])
# Is the header present?
AC_MSG_CHECKING([$1 presence])
AC_PREPROC_IFELSE([AC_LANG_SOURCE([@%:@include <$1>])],
[ac_header_preproc=yes],
[ac_header_preproc=no])
AC_MSG_RESULT([$ac_header_preproc])
# So? What about this header?
case $ac_header_compiler:$ac_header_preproc in
yes:no )
AC_MSG_WARN([$1: accepted by the compiler, rejected by the preprocessor!])
AC_MSG_WARN([$1: proceeding with the preprocessor's result]);;
no:yes )
AC_MSG_WARN([$1: present but cannot be compiled])
AC_MSG_WARN([$1: check for missing prerequisite headers?])
AC_MSG_WARN([$1: proceeding with the preprocessor's result]);;
esac
AC_CACHE_CHECK([for $1], ac_Header,
[AS_VAR_SET(ac_Header, $ac_header_preproc)])
])dnl ! set ac_HEADER
AS_IF([test AS_VAR_GET(ac_Header) = yes], [$2], [$3])[]dnl
AS_VAR_POPDEF([ac_Header])dnl
])# _AC_CHECK_HEADER_MONGREL
# _AC_CHECK_HEADER_NEW(HEADER-FILE,
# [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND],
# [INCLUDES])
# --------------------------------------------------------------
# Check the compiler accepts HEADER-FILE. The INCLUDES are defaulted.
m4_define([_AC_CHECK_HEADER_NEW],
AC_DEFUN([AC_CHECK_HEADER],
[AS_VAR_PUSHDEF([ac_Header], [ac_cv_header_$1])dnl
AC_CACHE_CHECK([for $1], ac_Header,
[AC_COMPILE_IFELSE([AC_LANG_SOURCE([AC_INCLUDES_DEFAULT([$4])
@ -152,22 +77,7 @@ AC_CACHE_CHECK([for $1], ac_Header,
[AS_VAR_SET(ac_Header, no)])])
AS_IF([test AS_VAR_GET(ac_Header) = yes], [$2], [$3])[]dnl
AS_VAR_POPDEF([ac_Header])dnl
])# _AC_CHECK_HEADER_NEW
# _AC_CHECK_HEADER_OLD(HEADER-FILE,
# [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
# --------------------------------------------------------------
# Check the preprocessor accepts HEADER-FILE.
m4_define([_AC_CHECK_HEADER_OLD],
[AS_VAR_PUSHDEF([ac_Header], [ac_cv_header_$1])dnl
AC_CACHE_CHECK([for $1], ac_Header,
[AC_PREPROC_IFELSE([AC_LANG_SOURCE([@%:@include <$1>])],
[AS_VAR_SET(ac_Header, yes)],
[AS_VAR_SET(ac_Header, no)])])
AS_IF([test AS_VAR_GET(ac_Header) = yes], [$2], [$3])[]dnl
AS_VAR_POPDEF([ac_Header])dnl
])# _AC_CHECK_HEADER_OLD
])# AC_CHECK_HEADER
# AH_CHECK_HEADERS(HEADER-FILE...)