File: include_next.m4

package info (click to toggle)
shishi 1.0.0-1
  • links: PTS, VCS
  • area: main
  • in suites: squeeze
  • size: 22,144 kB
  • ctags: 7,865
  • sloc: ansic: 61,153; sh: 12,212; yacc: 1,219; makefile: 1,164; perl: 624; sed: 16
file content (187 lines) | stat: -rw-r--r-- 7,799 bytes parent folder | download | duplicates (72)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
# include_next.m4 serial 14
dnl Copyright (C) 2006-2010 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 From Paul Eggert and Derek Price.

dnl Sets INCLUDE_NEXT and PRAGMA_SYSTEM_HEADER.
dnl
dnl INCLUDE_NEXT expands to 'include_next' if the compiler supports it, or to
dnl 'include' otherwise.
dnl
dnl INCLUDE_NEXT_AS_FIRST_DIRECTIVE expands to 'include_next' if the compiler
dnl supports it in the special case that it is the first include directive in
dnl the given file, or to 'include' otherwise.
dnl
dnl PRAGMA_SYSTEM_HEADER can be used in files that contain #include_next,
dnl so as to avoid GCC warnings when the gcc option -pedantic is used.
dnl '#pragma GCC system_header' has the same effect as if the file was found
dnl through the include search path specified with '-isystem' options (as
dnl opposed to the search path specified with '-I' options). Namely, gcc
dnl does not warn about some things, and on some systems (Solaris and Interix)
dnl __STDC__ evaluates to 0 instead of to 1. The latter is an undesired side
dnl effect; we are therefore careful to use 'defined __STDC__' or '1' instead
dnl of plain '__STDC__'.

AC_DEFUN([gl_INCLUDE_NEXT],
[
  AC_LANG_PREPROC_REQUIRE()
  AC_CACHE_CHECK([whether the preprocessor supports include_next],
    [gl_cv_have_include_next],
    [rm -rf conftestd1a conftestd1b conftestd2
     mkdir conftestd1a conftestd1b conftestd2
     dnl IBM C 9.0, 10.1 (original versions, prior to the 2009-01 updates) on
     dnl AIX 6.1 support include_next when used as first preprocessor directive
     dnl in a file, but not when preceded by another include directive. Check
     dnl for this bug by including <stdio.h>.
     dnl Additionally, with this same compiler, include_next is a no-op when
     dnl used in a header file that was included by specifying its absolute
     dnl file name. Despite these two bugs, include_next is used in the
     dnl compiler's <math.h>. By virtue of the second bug, we need to use
     dnl include_next as well in this case.
     cat <<EOF > conftestd1a/conftest.h
#define DEFINED_IN_CONFTESTD1
#include_next <conftest.h>
#ifdef DEFINED_IN_CONFTESTD2
int foo;
#else
#error "include_next doesn't work"
#endif
EOF
     cat <<EOF > conftestd1b/conftest.h
#define DEFINED_IN_CONFTESTD1
#include <stdio.h>
#include_next <conftest.h>
#ifdef DEFINED_IN_CONFTESTD2
int foo;
#else
#error "include_next doesn't work"
#endif
EOF
     cat <<EOF > conftestd2/conftest.h
#ifndef DEFINED_IN_CONFTESTD1
#error "include_next test doesn't work"
#endif
#define DEFINED_IN_CONFTESTD2
EOF
     gl_save_CPPFLAGS="$CPPFLAGS"
     CPPFLAGS="$gl_save_CPPFLAGS -Iconftestd1b -Iconftestd2"
     AC_COMPILE_IFELSE([#include <conftest.h>],
       [gl_cv_have_include_next=yes],
       [CPPFLAGS="$gl_save_CPPFLAGS -Iconftestd1a -Iconftestd2"
        AC_COMPILE_IFELSE([#include <conftest.h>],
          [gl_cv_have_include_next=buggy],
          [gl_cv_have_include_next=no])
       ])
     CPPFLAGS="$gl_save_CPPFLAGS"
     rm -rf conftestd1a conftestd1b conftestd2
    ])
  PRAGMA_SYSTEM_HEADER=
  if test $gl_cv_have_include_next = yes; then
    INCLUDE_NEXT=include_next
    INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include_next
    if test -n "$GCC"; then
      PRAGMA_SYSTEM_HEADER='#pragma GCC system_header'
    fi
  else
    if test $gl_cv_have_include_next = buggy; then
      INCLUDE_NEXT=include
      INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include_next
    else
      INCLUDE_NEXT=include
      INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include
    fi
  fi
  AC_SUBST([INCLUDE_NEXT])
  AC_SUBST([INCLUDE_NEXT_AS_FIRST_DIRECTIVE])
  AC_SUBST([PRAGMA_SYSTEM_HEADER])
])

# gl_CHECK_NEXT_HEADERS(HEADER1 HEADER2 ...)
# ------------------------------------------
# For each arg foo.h, if #include_next works, define NEXT_FOO_H to be
# '<foo.h>'; otherwise define it to be
# '"///usr/include/foo.h"', or whatever other absolute file name is suitable.
# Also, if #include_next works as first preprocessing directive in a file,
# define NEXT_AS_FIRST_DIRECTIVE_FOO_H to be '<foo.h>'; otherwise define it to
# be
# '"///usr/include/foo.h"', or whatever other absolute file name is suitable.
# That way, a header file with the following line:
#       #@INCLUDE_NEXT@ @NEXT_FOO_H@
# or
#       #@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_AS_FIRST_DIRECTIVE_FOO_H@
# behaves (after sed substitution) as if it contained
#       #include_next <foo.h>
# even if the compiler does not support include_next.
# The three "///" are to pacify Sun C 5.8, which otherwise would say
# "warning: #include of /usr/include/... may be non-portable".
# Use `""', not `<>', so that the /// cannot be confused with a C99 comment.
# Note: This macro assumes that the header file is not empty after
# preprocessing, i.e. it does not only define preprocessor macros but also
# provides some type/enum definitions or function/variable declarations.
AC_DEFUN([gl_CHECK_NEXT_HEADERS],
[
  AC_REQUIRE([gl_INCLUDE_NEXT])
  AC_REQUIRE([AC_CANONICAL_HOST])
  AC_CHECK_HEADERS_ONCE([$1])

  m4_foreach_w([gl_HEADER_NAME], [$1],
    [AS_VAR_PUSHDEF([gl_next_header],
                    [gl_cv_next_]m4_defn([gl_HEADER_NAME]))
     if test $gl_cv_have_include_next = yes; then
       AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>'])
     else
       AC_CACHE_CHECK(
         [absolute name of <]m4_defn([gl_HEADER_NAME])[>],
         m4_defn([gl_next_header]),
         [AS_VAR_PUSHDEF([gl_header_exists],
                         [ac_cv_header_]m4_defn([gl_HEADER_NAME]))
          if test AS_VAR_GET(gl_header_exists) = yes; then
            AC_LANG_CONFTEST(
              [AC_LANG_SOURCE(
                 [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]]
               )])
            dnl AIX "xlc -E" and "cc -E" omit #line directives for header files
            dnl that contain only a #include of other header files and no
            dnl non-comment tokens of their own. This leads to a failure to
            dnl detect the absolute name of <dirent.h>, <signal.h>, <poll.h>
            dnl and others. The workaround is to force preservation of comments
            dnl through option -C. This ensures all necessary #line directives
            dnl are present. GCC supports option -C as well.
            case "$host_os" in
              aix*) gl_absname_cpp="$ac_cpp -C" ;;
              *)    gl_absname_cpp="$ac_cpp" ;;
            esac
            dnl eval is necessary to expand gl_absname_cpp.
            dnl Ultrix and Pyramid sh refuse to redirect output of eval,
            dnl so use subshell.
            AS_VAR_SET([gl_next_header],
              ['"'`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
               sed -n '\#/]m4_defn([gl_HEADER_NAME])[#{
                 s#.*"\(.*/]m4_defn([gl_HEADER_NAME])[\)".*#\1#
                 s#^/[^/]#//&#
                 p
                 q
               }'`'"'])
          else
            AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>'])
          fi
          AS_VAR_POPDEF([gl_header_exists])])
     fi
     AC_SUBST(
       AS_TR_CPP([NEXT_]m4_defn([gl_HEADER_NAME])),
       [AS_VAR_GET([gl_next_header])])
     if test $gl_cv_have_include_next = yes || test $gl_cv_have_include_next = buggy; then
       # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include_next'
       gl_next_as_first_directive='<'gl_HEADER_NAME'>'
     else
       # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include'
       gl_next_as_first_directive=AS_VAR_GET([gl_next_header])
     fi
     AC_SUBST(
       AS_TR_CPP([NEXT_AS_FIRST_DIRECTIVE_]m4_defn([gl_HEADER_NAME])),
       [$gl_next_as_first_directive])
     AS_VAR_POPDEF([gl_next_header])])
])