diff options
Diffstat (limited to 'm4/include_next.m4')
| -rw-r--r-- | m4/include_next.m4 | 99 |
1 files changed, 63 insertions, 36 deletions
diff --git a/m4/include_next.m4 b/m4/include_next.m4 index e37eb056..b3c78491 100644 --- a/m4/include_next.m4 +++ b/m4/include_next.m4 @@ -1,5 +1,5 @@ -# include_next.m4 serial 16 -dnl Copyright (C) 2006-2010 Free Software Foundation, Inc. +# include_next.m4 serial 18 +dnl Copyright (C) 2006-2011 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. @@ -147,11 +147,33 @@ choke me # 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. +# +# This macro also checks whether each header exists, by invoking +# AC_CHECK_HEADERS_ONCE or AC_CHECK_HEADERS on each argument. AC_DEFUN([gl_CHECK_NEXT_HEADERS], [ + gl_NEXT_HEADERS_INTERNAL([$1], [check]) +]) + +# gl_NEXT_HEADERS(HEADER1 HEADER2 ...) +# ------------------------------------ +# Like gl_CHECK_NEXT_HEADERS, except do not check whether the headers exist. +# This is suitable for headers like <stddef.h> that are standardized by C89 +# and therefore can be assumed to exist. +AC_DEFUN([gl_NEXT_HEADERS], +[ + gl_NEXT_HEADERS_INTERNAL([$1], [assume]) +]) + +# The guts of gl_CHECK_NEXT_HEADERS and gl_NEXT_HEADERS. +AC_DEFUN([gl_NEXT_HEADERS_INTERNAL], +[ AC_REQUIRE([gl_INCLUDE_NEXT]) AC_REQUIRE([AC_CANONICAL_HOST]) - AC_CHECK_HEADERS_ONCE([$1]) + + m4_if([$2], [check], + [AC_CHECK_HEADERS_ONCE([$1]) + ]) m4_foreach_w([gl_HEADER_NAME], [$1], [AS_VAR_PUSHDEF([gl_next_header], @@ -162,39 +184,44 @@ AC_DEFUN([gl_CHECK_NEXT_HEADERS], AC_CACHE_CHECK( [absolute name of <]m4_defn([gl_HEADER_NAME])[>], m4_defn([gl_next_header]), - [AS_VAR_PUSHDEF([gl_header_exists], - [ac_cv_header_]m4_defn([gl_HEADER_NAME])) - if test AS_VAR_GET(gl_header_exists) = yes; then - AC_LANG_CONFTEST( - [AC_LANG_SOURCE( - [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]] - )]) - dnl AIX "xlc -E" and "cc -E" omit #line directives for header files - dnl that contain only a #include of other header files and no - dnl non-comment tokens of their own. This leads to a failure to - dnl detect the absolute name of <dirent.h>, <signal.h>, <poll.h> - dnl and others. The workaround is to force preservation of comments - dnl through option -C. This ensures all necessary #line directives - dnl are present. GCC supports option -C as well. - case "$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])]) + [m4_if([$2], [check], + [AS_VAR_PUSHDEF([gl_header_exists], + [ac_cv_header_]m4_defn([gl_HEADER_NAME])) + if test AS_VAR_GET(gl_header_exists) = yes; then + AS_VAR_POPDEF([gl_header_exists]) + ]) + AC_LANG_CONFTEST( + [AC_LANG_SOURCE( + [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]] + )]) + dnl AIX "xlc -E" and "cc -E" omit #line directives for header + dnl files that contain only a #include of other header files and + dnl no non-comment tokens of their own. This leads to a failure + dnl to detect the absolute name of <dirent.h>, <signal.h>, + dnl <poll.h> and others. The workaround is to force preservation + dnl of comments through option -C. This ensures all necessary + dnl #line directives are present. GCC supports option -C as well. + case "$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 + }'`'"']) + m4_if([$2], [check], + [else + AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>']) + fi + ]) + ]) fi AC_SUBST( AS_TR_CPP([NEXT_]m4_defn([gl_HEADER_NAME])), |