X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fabsolute-header.m4;h=400de55353c79fd0330646e95f976c58373e9a25;hb=531e3287a33c005edeeba10b0ab0910c6686e049;hp=87b0961f6c1907d0d163b9a916a397ec6b68c7fa;hpb=b2e2010c7c902235b5efb5bd3c6529f61b093aa4;p=gnulib.git

diff --git a/m4/absolute-header.m4 b/m4/absolute-header.m4
index 87b0961f6..400de5535 100644
--- a/m4/absolute-header.m4
+++ b/m4/absolute-header.m4
@@ -1,5 +1,5 @@
-# absolute-header.m4 serial 11
-dnl Copyright (C) 2006-2010 Free Software Foundation, Inc.
+# absolute-header.m4 serial 16
+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.
@@ -8,7 +8,7 @@ dnl From Derek Price.
 
 # gl_ABSOLUTE_HEADER(HEADER1 HEADER2 ...)
 # ---------------------------------------
-# Find the absolute name of a header file, assuming the header exists.
+# Find the absolute name of a header file, testing first if the header exists.
 # If the header were sys/inttypes.h, this macro would define
 # ABSOLUTE_SYS_INTTYPES_H to the `""' quoted absolute name of sys/inttypes.h
 # in config.h
@@ -22,6 +22,8 @@ dnl From Derek Price.
 AC_DEFUN([gl_ABSOLUTE_HEADER],
 [AC_REQUIRE([AC_CANONICAL_HOST])
 AC_LANG_PREPROC_REQUIRE()dnl
+dnl FIXME: gl_absolute_header and ac_header_exists must be used unquoted
+dnl until we can assume autoconf 2.64 or newer.
 m4_foreach_w([gl_HEADER_NAME], [$1],
   [AS_VAR_PUSHDEF([gl_absolute_header],
                   [gl_cv_absolute_]m4_defn([gl_HEADER_NAME]))dnl
@@ -31,29 +33,7 @@ m4_foreach_w([gl_HEADER_NAME], [$1],
                     [ac_cv_header_]m4_defn([gl_HEADER_NAME]))dnl
     AC_CHECK_HEADERS_ONCE(m4_defn([gl_HEADER_NAME]))dnl
     if test AS_VAR_GET(ac_header_exists) = yes; then
-      AC_LANG_CONFTEST([AC_LANG_SOURCE([[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]])])
-      dnl AIX "xlc -E" and "cc -E" omit #line directives for header files
-      dnl that contain only a #include of other header files and no
-      dnl non-comment tokens of their own. This leads to a failure to
-      dnl detect the absolute name of <dirent.h>, <signal.h>, <poll.h>
-      dnl and others. The workaround is to force preservation of comments
-      dnl through option -C. This ensures all necessary #line directives
-      dnl are present. GCC supports option -C as well.
-      case "$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_absolute_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
-}'`])
+      gl_ABSOLUTE_HEADER_ONE(m4_defn([gl_HEADER_NAME]))
     fi
     AS_VAR_POPDEF([ac_header_exists])dnl
     ])dnl
@@ -63,3 +43,60 @@ sed -n '\#/]m4_defn([gl_HEADER_NAME])[#{
   AS_VAR_POPDEF([gl_absolute_header])dnl
 ])dnl
 ])# gl_ABSOLUTE_HEADER
+
+# gl_ABSOLUTE_HEADER_ONE(HEADER)
+# ------------------------------
+# Like gl_ABSOLUTE_HEADER, except that:
+#   - it assumes that the header exists,
+#   - it uses the current CPPFLAGS,
+#   - it does not cache the result,
+#   - it is silent.
+AC_DEFUN([gl_ABSOLUTE_HEADER_ONE],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_LANG_CONFTEST([AC_LANG_SOURCE([[#include <]]m4_dquote([$1])[[>]])])
+  dnl AIX "xlc -E" and "cc -E" omit #line directives for header files
+  dnl that contain only a #include of other header files and no
+  dnl non-comment tokens of their own. This leads to a failure to
+  dnl detect the absolute name of <dirent.h>, <signal.h>, <poll.h>
+  dnl and others. The workaround is to force preservation of comments
+  dnl through option -C. This ensures all necessary #line directives
+  dnl are present. GCC supports option -C as well.
+  case "$host_os" in
+    aix*) gl_absname_cpp="$ac_cpp -C" ;;
+    *)    gl_absname_cpp="$ac_cpp" ;;
+  esac
+changequote(,)
+  case "$host_os" in
+    mingw*)
+      dnl For the sake of native Windows compilers (excluding gcc),
+      dnl treat backslash as a directory separator, like /.
+      dnl Actually, these compilers use a double-backslash as
+      dnl directory separator, inside the
+      dnl   # line "filename"
+      dnl directives.
+      gl_dirsep_regex='[/\\]'
+      ;;
+    *)
+      gl_dirsep_regex='\/'
+      ;;
+  esac
+  dnl A sed expression that turns a string into a basic regular
+  dnl expression, for use within "/.../".
+  gl_make_literal_regex_sed='s,[]$^\\.*/[],\\&,g'
+  gl_header_literal_regex=`echo '$1' \
+                           | sed -e "$gl_make_literal_regex_sed"`
+  gl_absolute_header_sed="/${gl_dirsep_regex}${gl_header_literal_regex}/"'{
+      s/.*"\(.*'"${gl_dirsep_regex}${gl_header_literal_regex}"'\)".*/\1/
+      s|^/[^/]|//&|
+      p
+      q
+    }'
+changequote([,])
+  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_cv_absolute_]AS_TR_SH([[$1]]),
+[`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
+  sed -n "$gl_absolute_header_sed"`])
+])