[committed] libstdc++: Add --disable-libstdcxx-hosted as an alias for hosted-libstdcxx

[Jonathan Wakely <jwakely@redhat.com>]

Tested x86_64-linux, Pushed to trunk.

-- >8 --

Most libstdc++ configure args are of the form --enable-libstdcxx-xxx but
the option to build freestanding is --disable-hosted-libstdcxx. If you
accidentally type --disable-libstdcxx-hosted then it will be ignored.

This adds --disable-libstdcxx-hosted as an alias for the existing arg,
so it works whichever way you say it. If both args are used explicitly
and their values do not agree, configure fails with an error.

libstdc++-v3/ChangeLog:

	* acinclude.m4 (GLIBCXX_ENABLE_HOSTED): Add libstdcxx-hosted
	enable arg as an alias for hosted-libstdcxx enable arg.
	* configure: Regenerate.
---
 libstdc++-v3/acinclude.m4 | 22 +++++++++++++++++++++-
 libstdc++-v3/configure    | 37 ++++++++++++++++++++++++++++---------
 2 files changed, 49 insertions(+), 10 deletions(-)

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 1b404d7df22..719eab15c77 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -2962,6 +2962,10 @@ dnl installing only the headers required by [17.4.1.3] and the language
 dnl support library.  More than that will be built (to keep the Makefiles
 dnl conveniently clean), but not installed.
 dnl
+dnl Also define --disable-libstdcxx-hosted as an alias for
+dnl --disable-hosted-libstdcxx but fail if both are given
+dnl and their values do not agree.
+dnl
 dnl Sets:
 dnl  is_hosted  (yes/no)
 dnl
@@ -2971,7 +2975,8 @@ dnl
 AC_DEFUN([GLIBCXX_ENABLE_HOSTED], [
   AC_ARG_ENABLE([hosted-libstdcxx],
     AC_HELP_STRING([--disable-hosted-libstdcxx],
-		   [only build freestanding C++ runtime support]),,
+		   [only build freestanding C++ runtime support]),
+    [enable_hosted_libstdcxx_was_given=yes],
     [case "$host" in
 	arm*-*-symbianelf*)
 	    enable_hosted_libstdcxx=no
@@ -2980,6 +2985,21 @@ AC_DEFUN([GLIBCXX_ENABLE_HOSTED], [
 	    enable_hosted_libstdcxx=yes
 	    ;;
      esac])
+
+  # Because most configure args are --enable-libstdcxx-foo add an alias
+  # of that form for --enable-hosted-libstdcxx.
+  AC_ARG_ENABLE([libstdcxx-hosted],
+    AC_HELP_STRING([--disable-libstdcxx-hosted],
+		   [alias for --disable-hosted-libstdcxx]),
+    [if test "$enable_hosted_libstdcxx_was_given" = yes; then
+      if test "$enable_hosted_libstdcxx" != "$enableval"; then
+	AC_MSG_ERROR([--enable-libstdcxx-hosted=$enableval conflicts with --enable-hosted-libstdcxx=$enable_hosted_libstdcxx])
+      fi
+    else
+      enable_hosted_libstdcxx=${enableval}
+    fi
+    ],)
+
   freestanding_flags=
   if test "$enable_hosted_libstdcxx" = no; then
     AC_MSG_NOTICE([Only freestanding libraries will be built])