Annotation of embedaddon/libiconv/srcm4/include_next.m4, revision 1.1.1.2
1.1.1.2 ! misho 1: # include_next.m4 serial 20
! 2: dnl Copyright (C) 2006-2011 Free Software Foundation, Inc.
1.1 misho 3: dnl This file is free software; the Free Software Foundation
4: dnl gives unlimited permission to copy and/or distribute it,
5: dnl with or without modifications, as long as this notice is preserved.
6:
7: dnl From Paul Eggert and Derek Price.
8:
9: dnl Sets INCLUDE_NEXT and PRAGMA_SYSTEM_HEADER.
10: dnl
11: dnl INCLUDE_NEXT expands to 'include_next' if the compiler supports it, or to
12: dnl 'include' otherwise.
13: dnl
14: dnl INCLUDE_NEXT_AS_FIRST_DIRECTIVE expands to 'include_next' if the compiler
15: dnl supports it in the special case that it is the first include directive in
16: dnl the given file, or to 'include' otherwise.
17: dnl
18: dnl PRAGMA_SYSTEM_HEADER can be used in files that contain #include_next,
19: dnl so as to avoid GCC warnings when the gcc option -pedantic is used.
20: dnl '#pragma GCC system_header' has the same effect as if the file was found
21: dnl through the include search path specified with '-isystem' options (as
22: dnl opposed to the search path specified with '-I' options). Namely, gcc
23: dnl does not warn about some things, and on some systems (Solaris and Interix)
24: dnl __STDC__ evaluates to 0 instead of to 1. The latter is an undesired side
25: dnl effect; we are therefore careful to use 'defined __STDC__' or '1' instead
26: dnl of plain '__STDC__'.
1.1.1.2 ! misho 27: dnl
! 28: dnl PRAGMA_COLUMNS can be used in files that override system header files, so
! 29: dnl as to avoid compilation errors on HP NonStop systems when the gnulib file
! 30: dnl is included by a system header file that does a "#pragma COLUMNS 80" (which
! 31: dnl has the effect of truncating the lines of that file and all files that it
! 32: dnl includes to 80 columns) and the gnulib file has lines longer than 80
! 33: dnl columns.
1.1 misho 34:
35: AC_DEFUN([gl_INCLUDE_NEXT],
36: [
37: AC_LANG_PREPROC_REQUIRE()
38: AC_CACHE_CHECK([whether the preprocessor supports include_next],
39: [gl_cv_have_include_next],
40: [rm -rf conftestd1a conftestd1b conftestd2
41: mkdir conftestd1a conftestd1b conftestd2
42: dnl IBM C 9.0, 10.1 (original versions, prior to the 2009-01 updates) on
43: dnl AIX 6.1 support include_next when used as first preprocessor directive
44: dnl in a file, but not when preceded by another include directive. Check
45: dnl for this bug by including <stdio.h>.
46: dnl Additionally, with this same compiler, include_next is a no-op when
47: dnl used in a header file that was included by specifying its absolute
48: dnl file name. Despite these two bugs, include_next is used in the
49: dnl compiler's <math.h>. By virtue of the second bug, we need to use
50: dnl include_next as well in this case.
51: cat <<EOF > conftestd1a/conftest.h
52: #define DEFINED_IN_CONFTESTD1
53: #include_next <conftest.h>
54: #ifdef DEFINED_IN_CONFTESTD2
55: int foo;
56: #else
57: #error "include_next doesn't work"
58: #endif
59: EOF
60: cat <<EOF > conftestd1b/conftest.h
61: #define DEFINED_IN_CONFTESTD1
62: #include <stdio.h>
63: #include_next <conftest.h>
64: #ifdef DEFINED_IN_CONFTESTD2
65: int foo;
66: #else
67: #error "include_next doesn't work"
68: #endif
69: EOF
70: cat <<EOF > conftestd2/conftest.h
71: #ifndef DEFINED_IN_CONFTESTD1
72: #error "include_next test doesn't work"
73: #endif
74: #define DEFINED_IN_CONFTESTD2
75: EOF
76: gl_save_CPPFLAGS="$CPPFLAGS"
77: CPPFLAGS="$gl_save_CPPFLAGS -Iconftestd1b -Iconftestd2"
1.1.1.2 ! misho 78: dnl We intentionally avoid using AC_LANG_SOURCE here.
! 79: AC_COMPILE_IFELSE([AC_LANG_DEFINES_PROVIDED[#include <conftest.h>]],
1.1 misho 80: [gl_cv_have_include_next=yes],
81: [CPPFLAGS="$gl_save_CPPFLAGS -Iconftestd1a -Iconftestd2"
1.1.1.2 ! misho 82: AC_COMPILE_IFELSE([AC_LANG_DEFINES_PROVIDED[#include <conftest.h>]],
1.1 misho 83: [gl_cv_have_include_next=buggy],
84: [gl_cv_have_include_next=no])
85: ])
86: CPPFLAGS="$gl_save_CPPFLAGS"
87: rm -rf conftestd1a conftestd1b conftestd2
88: ])
89: PRAGMA_SYSTEM_HEADER=
90: if test $gl_cv_have_include_next = yes; then
91: INCLUDE_NEXT=include_next
92: INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include_next
93: if test -n "$GCC"; then
94: PRAGMA_SYSTEM_HEADER='#pragma GCC system_header'
95: fi
96: else
97: if test $gl_cv_have_include_next = buggy; then
98: INCLUDE_NEXT=include
99: INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include_next
100: else
101: INCLUDE_NEXT=include
102: INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include
103: fi
104: fi
105: AC_SUBST([INCLUDE_NEXT])
106: AC_SUBST([INCLUDE_NEXT_AS_FIRST_DIRECTIVE])
107: AC_SUBST([PRAGMA_SYSTEM_HEADER])
1.1.1.2 ! misho 108: AC_CACHE_CHECK([whether system header files limit the line length],
! 109: [gl_cv_pragma_columns],
! 110: [dnl HP NonStop systems, which define __TANDEM, have this misfeature.
! 111: AC_EGREP_CPP([choke me],
! 112: [
! 113: #ifdef __TANDEM
! 114: choke me
! 115: #endif
! 116: ],
! 117: [gl_cv_pragma_columns=yes],
! 118: [gl_cv_pragma_columns=no])
! 119: ])
! 120: if test $gl_cv_pragma_columns = yes; then
! 121: PRAGMA_COLUMNS="#pragma COLUMNS 10000"
! 122: else
! 123: PRAGMA_COLUMNS=
! 124: fi
! 125: AC_SUBST([PRAGMA_COLUMNS])
1.1 misho 126: ])
127:
128: # gl_CHECK_NEXT_HEADERS(HEADER1 HEADER2 ...)
129: # ------------------------------------------
130: # For each arg foo.h, if #include_next works, define NEXT_FOO_H to be
131: # '<foo.h>'; otherwise define it to be
132: # '"///usr/include/foo.h"', or whatever other absolute file name is suitable.
133: # Also, if #include_next works as first preprocessing directive in a file,
134: # define NEXT_AS_FIRST_DIRECTIVE_FOO_H to be '<foo.h>'; otherwise define it to
135: # be
136: # '"///usr/include/foo.h"', or whatever other absolute file name is suitable.
137: # That way, a header file with the following line:
1.1.1.2 ! misho 138: # #@INCLUDE_NEXT@ @NEXT_FOO_H@
1.1 misho 139: # or
1.1.1.2 ! misho 140: # #@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_AS_FIRST_DIRECTIVE_FOO_H@
1.1 misho 141: # behaves (after sed substitution) as if it contained
1.1.1.2 ! misho 142: # #include_next <foo.h>
1.1 misho 143: # even if the compiler does not support include_next.
144: # The three "///" are to pacify Sun C 5.8, which otherwise would say
145: # "warning: #include of /usr/include/... may be non-portable".
146: # Use `""', not `<>', so that the /// cannot be confused with a C99 comment.
147: # Note: This macro assumes that the header file is not empty after
148: # preprocessing, i.e. it does not only define preprocessor macros but also
149: # provides some type/enum definitions or function/variable declarations.
1.1.1.2 ! misho 150: #
! 151: # This macro also checks whether each header exists, by invoking
! 152: # AC_CHECK_HEADERS_ONCE or AC_CHECK_HEADERS on each argument.
1.1 misho 153: AC_DEFUN([gl_CHECK_NEXT_HEADERS],
154: [
1.1.1.2 ! misho 155: gl_NEXT_HEADERS_INTERNAL([$1], [check])
! 156: ])
! 157:
! 158: # gl_NEXT_HEADERS(HEADER1 HEADER2 ...)
! 159: # ------------------------------------
! 160: # Like gl_CHECK_NEXT_HEADERS, except do not check whether the headers exist.
! 161: # This is suitable for headers like <stddef.h> that are standardized by C89
! 162: # and therefore can be assumed to exist.
! 163: AC_DEFUN([gl_NEXT_HEADERS],
! 164: [
! 165: gl_NEXT_HEADERS_INTERNAL([$1], [assume])
! 166: ])
! 167:
! 168: # The guts of gl_CHECK_NEXT_HEADERS and gl_NEXT_HEADERS.
! 169: AC_DEFUN([gl_NEXT_HEADERS_INTERNAL],
! 170: [
1.1 misho 171: AC_REQUIRE([gl_INCLUDE_NEXT])
172: AC_REQUIRE([AC_CANONICAL_HOST])
173:
1.1.1.2 ! misho 174: m4_if([$2], [check],
! 175: [AC_CHECK_HEADERS_ONCE([$1])
! 176: ])
! 177:
! 178: dnl FIXME: gl_next_header and gl_header_exists must be used unquoted
! 179: dnl until we can assume autoconf 2.64 or newer.
1.1 misho 180: m4_foreach_w([gl_HEADER_NAME], [$1],
181: [AS_VAR_PUSHDEF([gl_next_header],
1.1.1.2 ! misho 182: [gl_cv_next_]m4_defn([gl_HEADER_NAME]))
1.1 misho 183: if test $gl_cv_have_include_next = yes; then
1.1.1.2 ! misho 184: AS_VAR_SET(gl_next_header, ['<'gl_HEADER_NAME'>'])
1.1 misho 185: else
186: AC_CACHE_CHECK(
1.1.1.2 ! misho 187: [absolute name of <]m4_defn([gl_HEADER_NAME])[>],
! 188: m4_defn([gl_next_header]),
! 189: [m4_if([$2], [check],
! 190: [AS_VAR_PUSHDEF([gl_header_exists],
! 191: [ac_cv_header_]m4_defn([gl_HEADER_NAME]))
! 192: if test AS_VAR_GET(gl_header_exists) = yes; then
! 193: AS_VAR_POPDEF([gl_header_exists])
! 194: ])
! 195: AC_LANG_CONFTEST(
! 196: [AC_LANG_SOURCE(
! 197: [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]]
! 198: )])
! 199: dnl AIX "xlc -E" and "cc -E" omit #line directives for header
! 200: dnl files that contain only a #include of other header files and
! 201: dnl no non-comment tokens of their own. This leads to a failure
! 202: dnl to detect the absolute name of <dirent.h>, <signal.h>,
! 203: dnl <poll.h> and others. The workaround is to force preservation
! 204: dnl of comments through option -C. This ensures all necessary
! 205: dnl #line directives are present. GCC supports option -C as well.
! 206: case "$host_os" in
! 207: aix*) gl_absname_cpp="$ac_cpp -C" ;;
! 208: *) gl_absname_cpp="$ac_cpp" ;;
! 209: esac
! 210: dnl eval is necessary to expand gl_absname_cpp.
! 211: dnl Ultrix and Pyramid sh refuse to redirect output of eval,
! 212: dnl so use subshell.
! 213: AS_VAR_SET(gl_next_header,
! 214: ['"'`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
! 215: sed -n '\#/]m4_defn([gl_HEADER_NAME])[#{
! 216: s#.*"\(.*/]m4_defn([gl_HEADER_NAME])[\)".*#\1#
! 217: s#^/[^/]#//&#
! 218: p
! 219: q
! 220: }'`'"'])
! 221: m4_if([$2], [check],
! 222: [else
! 223: AS_VAR_SET(gl_next_header, ['<'gl_HEADER_NAME'>'])
! 224: fi
! 225: ])
! 226: ])
1.1 misho 227: fi
228: AC_SUBST(
229: AS_TR_CPP([NEXT_]m4_defn([gl_HEADER_NAME])),
1.1.1.2 ! misho 230: [AS_VAR_GET(gl_next_header)])
1.1 misho 231: if test $gl_cv_have_include_next = yes || test $gl_cv_have_include_next = buggy; then
232: # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include_next'
233: gl_next_as_first_directive='<'gl_HEADER_NAME'>'
234: else
235: # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include'
1.1.1.2 ! misho 236: gl_next_as_first_directive=AS_VAR_GET(gl_next_header)
1.1 misho 237: fi
238: AC_SUBST(
239: AS_TR_CPP([NEXT_AS_FIRST_DIRECTIVE_]m4_defn([gl_HEADER_NAME])),
240: [$gl_next_as_first_directive])
241: AS_VAR_POPDEF([gl_next_header])])
242: ])
1.1.1.2 ! misho 243:
! 244: # Autoconf 2.68 added warnings for our use of AC_COMPILE_IFELSE;
! 245: # this fallback is safe for all earlier autoconf versions.
! 246: m4_define_default([AC_LANG_DEFINES_PROVIDED])
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to include_next.m4 CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / libiconv / srcm4