2017-05-19  Nathan Sidwell  <nathan@acm.org>

	* configure.ac: Add --enable-languages=default to mean default and
	make --enable-languages=all mean all supported languages.
	* configure: Regenerated.
	gcc/
	* doc/invoke.texi (--enable-languages): Update documentation.

Index: configure.ac
===================================================================
--- configure.ac	(revision 248286)
+++ configure.ac	(working copy)
@@ -1766,6 +1766,13 @@ AC_ARG_ENABLE(linker-plugin-flags,
   extra_linker_plugin_flags=)
 AC_SUBST(extra_linker_plugin_flags)
 
+# Enable --enable-host-shared.
+# Checked early to determine whether jit is an 'all' language
+AC_ARG_ENABLE(host-shared,
+[AS_HELP_STRING([--enable-host-shared],
+		[build host code as shared libraries])],
+[host_shared=$enableval], [host_shared=no])
+AC_SUBST(host_shared)
 
 # By default, C and C++ are the only stage 1 languages.
 stage1_languages=,c,
@@ -1784,7 +1791,7 @@ if test -d ${srcdir}/gcc; then
       enable_languages="${LANGUAGES}"
         echo configure.ac: warning: setting LANGUAGES is deprecated, use --enable-languages instead 1>&2
     else
-      enable_languages=all
+      enable_languages=default
     fi
   else
     if test x"${enable_languages}" = x ||
@@ -1836,6 +1843,7 @@ if test -d ${srcdir}/gcc; then
         for other in ${lang_requires} ${lang_requires_boot_languages}; do
           case ,${enable_languages}, in
 	    *,$other,*) ;;
+	    *,default,*) ;;
 	    *,all,*) ;;
 	    *,$language,*)
 	      echo " \`$other' language required by \`$language'; enabling" 1>&2
@@ -1847,6 +1855,7 @@ if test -d ${srcdir}/gcc; then
 	  if test "$other" != "c"; then
 	    case ,${enable_stage1_languages}, in
 	      *,$other,*) ;;
+	      *,default,*) ;;
 	      *,all,*) ;;
 	      *)
 		case ,${enable_languages}, in
@@ -1884,7 +1893,7 @@ if test -d ${srcdir}/gcc; then
     esac
   fi
 
-  missing_languages=`echo ",$enable_languages," | sed -e s/,all,/,/ -e s/,c,/,/ `
+  missing_languages=`echo ",$enable_languages," | sed -e s/,default,/,/ -e s/,all,/,/ -e s/,c,/,/ `
   potential_languages=,c,
 
   enabled_target_libs=
@@ -1916,21 +1925,27 @@ if test -d ${srcdir}/gcc; then
 	fi
 
         add_this_lang=no
-        case ,${enable_languages}, in
-          *,${language},*)
-            # Language was explicitly selected; include it
-	    # unless it is C, which is enabled by default.
-	    if test "$language" != "c"; then
+        # C is always enabled, so no need to add it again
+        if test "$language" != "c"; then
+          case ,${enable_languages}, in
+            *,${language},*)
+              # Language was explicitly selected; include it
 	      add_this_lang=yes
-	    fi
-            ;;
-          *,all,*)
-            # 'all' was selected, select it if it is a default language
-	    if test "$language" != "c"; then
+              ;;
+	    *,all,*)
+	      # All languages are enabled
+	      if test "$language:$host_shared" = "jit:no" ; then
+	        AC_MSG_WARN([not enabling language "jit" as --enable-host-shared not specified])
+	      else
+	        add_this_lang=yes
+	      fi
+              ;;
+            *,default,*)
+              # 'default' was selected, select it if it is a default language
 	      add_this_lang=${build_by_default}
-	    fi
-            ;;
-        esac
+              ;;
+          esac
+        fi
 
         # Disable languages that need other directories if these aren't available.
 	for i in $subdir_requires; do
@@ -1959,6 +1974,8 @@ if test -d ${srcdir}/gcc; then
             ;;
         esac
 
+        # Disable jit if -enable-host-shared not specified
+
 	# Disable a language that is unsupported by the target.
 	case " $unsupported_languages " in
 	  *" $language "*)
@@ -3478,13 +3495,6 @@ fi
 
 AC_SUBST(stage2_werror_flag)
 
-# Enable --enable-host-shared.
-AC_ARG_ENABLE(host-shared,
-[AS_HELP_STRING([--enable-host-shared],
-		[build host code as shared libraries])],
-[host_shared=$enableval], [host_shared=no])
-AC_SUBST(host_shared)
-
 # PR jit/64780: Require the user to explicitly specify
 # --enable-host-shared if the jit is enabled, hinting
 # that they might want to do a separate configure/build of
Index: gcc/doc/install.texi
===================================================================
--- gcc/doc/install.texi	(revision 248286)
+++ gcc/doc/install.texi	(working copy)
@@ -1621,14 +1621,17 @@ their runtime libraries should be built.
 grep ^language= */config-lang.in
 @end smallexample
 Currently, you can use any of the following:
-@code{all}, @code{ada}, @code{c}, @code{c++}, @code{fortran},
+@code{all}, @code{default}, @code{ada}, @code{c}, @code{c++}, @code{fortran},
 @code{go}, @code{jit}, @code{lto}, @code{objc}, @code{obj-c++}.
 Building the Ada compiler has special requirements, see below.
-If you do not pass this flag, or specify the option @code{all}, then all
+If you do not pass this flag, or specify the option @code{default}, then the
 default languages available in the @file{gcc} sub-tree will be configured.
 Ada, Go, Jit, and Objective-C++ are not default languages.  LTO is not a
 default language, but is built by default because @option{--enable-lto} is
-enabled by default.  The other languages are default languages.
+enabled by default.  The other languages are default languages.  If
+@code{all} is specified, then all available languages are built.  An
+exception is @code{jit} language, which requires
+@option{--enable-host-shared} to be included with @code{all}.
 
 @item --enable-stage1-languages=@var{lang1},@var{lang2},@dots{}
 Specify that a particular subset of compilers and their runtime
Index: configure
===================================================================
--- configure	(revision 248286)
+++ configure	(working copy)
@@ -556,7 +556,6 @@ enable_option_checking=no
 ac_subst_vars='LTLIBOBJS
 LIBOBJS
 compare_exclusions
-host_shared
 stage2_werror_flag
 stage1_checking
 stage1_cflags
@@ -645,6 +644,7 @@ get_gcc_base_ver
 extra_host_zlib_configure_flags
 extra_host_libiberty_configure_flags
 stage1_languages
+host_shared
 extra_linker_plugin_flags
 extra_linker_plugin_configure_flags
 islinc
@@ -781,6 +781,7 @@ enable_isl_version_check
 enable_lto
 enable_linker_plugin_configure_flags
 enable_linker_plugin_flags
+enable_host_shared
 enable_stage1_languages
 enable_objc_gc
 with_target_bdw_gc
@@ -796,7 +797,6 @@ with_build_time_tools
 enable_maintainer_mode
 enable_stage1_checking
 enable_werror
-enable_host_shared
 '
       ac_precious_vars='build_alias
 host_alias
@@ -1498,6 +1498,7 @@ Optional Features:
   --enable-linker-plugin-flags=FLAGS
                           additional flags for configuring and building linker
                           plugins [none]
+  --enable-host-shared    build host code as shared libraries
   --enable-stage1-languages[=all]
                           choose additional languages to build during stage1.
                           Mostly useful for compiler development
@@ -1515,7 +1516,6 @@ Optional Features:
                           choose additional checking for stage1 of the
                           compiler
   --enable-werror         enable -Werror in bootstrap stage2 and later
-  --enable-host-shared    build host code as shared libraries
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -6090,6 +6090,16 @@ fi
 
 
 
+# Enable --enable-host-shared.
+# Checked early to determine whether jit is an 'all' language
+# Check whether --enable-host-shared was given.
+if test "${enable_host_shared+set}" = set; then :
+  enableval=$enable_host_shared; host_shared=$enableval
+else
+  host_shared=no
+fi
+
+
 
 # By default, C and C++ are the only stage 1 languages.
 stage1_languages=,c,
@@ -6108,7 +6118,7 @@ if test -d ${srcdir}/gcc; then
       enable_languages="${LANGUAGES}"
         echo configure.ac: warning: setting LANGUAGES is deprecated, use --enable-languages instead 1>&2
     else
-      enable_languages=all
+      enable_languages=default
     fi
   else
     if test x"${enable_languages}" = x ||
@@ -6160,6 +6170,7 @@ if test -d ${srcdir}/gcc; then
         for other in ${lang_requires} ${lang_requires_boot_languages}; do
           case ,${enable_languages}, in
 	    *,$other,*) ;;
+	    *,default,*) ;;
 	    *,all,*) ;;
 	    *,$language,*)
 	      echo " \`$other' language required by \`$language'; enabling" 1>&2
@@ -6171,6 +6182,7 @@ if test -d ${srcdir}/gcc; then
 	  if test "$other" != "c"; then
 	    case ,${enable_stage1_languages}, in
 	      *,$other,*) ;;
+	      *,default,*) ;;
 	      *,all,*) ;;
 	      *)
 		case ,${enable_languages}, in
@@ -6208,7 +6220,7 @@ if test -d ${srcdir}/gcc; then
     esac
   fi
 
-  missing_languages=`echo ",$enable_languages," | sed -e s/,all,/,/ -e s/,c,/,/ `
+  missing_languages=`echo ",$enable_languages," | sed -e s/,default,/,/ -e s/,all,/,/ -e s/,c,/,/ `
   potential_languages=,c,
 
   enabled_target_libs=
@@ -6240,21 +6252,28 @@ if test -d ${srcdir}/gcc; then
 	fi
 
         add_this_lang=no
-        case ,${enable_languages}, in
-          *,${language},*)
-            # Language was explicitly selected; include it
-	    # unless it is C, which is enabled by default.
-	    if test "$language" != "c"; then
+        # C is always enabled, so no need to add it again
+        if test "$language" != "c"; then
+          case ,${enable_languages}, in
+            *,${language},*)
+              # Language was explicitly selected; include it
 	      add_this_lang=yes
-	    fi
-            ;;
-          *,all,*)
-            # 'all' was selected, select it if it is a default language
-	    if test "$language" != "c"; then
+              ;;
+	    *,all,*)
+	      # All languages are enabled
+	      if test "$language:$host_shared" = "jit:no" ; then
+	        { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: not enabling language \"jit\" as --enable-host-shared not specified" >&5
+$as_echo "$as_me: WARNING: not enabling language \"jit\" as --enable-host-shared not specified" >&2;}
+	      else
+	        add_this_lang=yes
+	      fi
+              ;;
+            *,default,*)
+              # 'default' was selected, select it if it is a default language
 	      add_this_lang=${build_by_default}
-	    fi
-            ;;
-        esac
+              ;;
+          esac
+        fi
 
         # Disable languages that need other directories if these aren't available.
 	for i in $subdir_requires; do
@@ -6283,6 +6302,8 @@ if test -d ${srcdir}/gcc; then
             ;;
         esac
 
+        # Disable jit if -enable-host-shared not specified
+
 	# Disable a language that is unsupported by the target.
 	case " $unsupported_languages " in
 	  *" $language "*)
@@ -14604,16 +14625,6 @@ if test -d ${srcdir}/gcc && test x"`cat
 fi
 
 
-
-# Enable --enable-host-shared.
-# Check whether --enable-host-shared was given.
-if test "${enable_host_shared+set}" = set; then :
-  enableval=$enable_host_shared; host_shared=$enableval
-else
-  host_shared=no
-fi
-
-
 
 # PR jit/64780: Require the user to explicitly specify
 # --enable-host-shared if the jit is enabled, hinting
