env: add spack env activate/deactivate and shell support

- `spack env activate foo`: sets SPACK_ENV to the current active env name

- `spack env deactivate`: unsets SPACK_ENV, deactivates the environment

- added support to setup_env.sh and setup_env.csh

- other env commands work properly with SPACK_ENV, as with an environment
  arguments.

- command-line --env arguments take precedence over the active
  environment, if given.

3 files changed, 80 insertions, 1 deletions

diff --git a/share/spack/csh/spack.csh b/share/spack/csh/spack.csh
index a78665beb3..6690f08eed 100644
--- a/share/spack/csh/spack.csh
+++ b/share/spack/csh/spack.csh
@@ -63,6 +63,47 @@ case cd:
         cd `\spack location $_sp_arg $_sp_args`
     endif
     breaksw
+case env:
+    shift _sp_args  # get rid of 'env'
+
+    set _sp_arg=""
+    [ $#_sp_args -gt 0 ] && set _sp_arg = ($_sp_args[1])
+
+    if ( "$_sp_arg" == "-h" ) then
+        \spack env -h
+    else
+        switch ($_sp_arg)
+            case activate:
+                set _sp_env_arg=""
+                [ $#_sp_args -gt 1 ] && set _sp_env_arg = ($_sp_args[2])
+
+                if ( "$_sp_env_arg" == "" || "$_sp_env_arg" =~ "-*" ) then
+                    # no args or does not start with -: just execute
+                    \spack $_sp_flags env $_sp_args
+                else
+                    shift _sp_args  # consume 'activate' or 'deactivate'
+                    # actual call to activate: source the output
+                    eval `\spack $_sp_flags env activate --csh $_sp_args`
+                endif
+                breaksw
+            case deactivate:
+                set _sp_env_arg=""
+                [ $#_sp_args -gt 1 ] && set _sp_env_arg = ($_sp_args[2])
+
+                if ( "$_sp_env_arg" != "" ) then
+                    # with args: execute the command
+                    \spack $_sp_flags env $_sp_args
+                else
+                    # no args: source the output
+                    eval `\spack $_sp_flags env deactivate --csh`
+                endif
+                breaksw
+            default:
+                echo default
+                \spack $_sp_flags env $_sp_args
+                breaksw
+        endsw
+    endif
 case use:
 case unuse:
 case load:
@@ -113,3 +154,4 @@ endsw
 _sp_end:
 unset _sp_args _sp_full_spec _sp_modtype _sp_module_args
 unset _sp_sh_cmd _sp_spec _sp_subcommand _sp_flags
+unset _sp_arg _sp_env_arg
diff --git a/share/spack/setup-env.csh b/share/spack/setup-env.csh
index cb45f8f74c..4e471b1121 100755
--- a/share/spack/setup-env.csh
+++ b/share/spack/setup-env.csh
@@ -28,5 +28,6 @@ if ($?SPACK_ROOT) then
     _spack_pathadd DK_NODE    "$_sp_dotkit_root/$_sp_sys_type"
     _spack_pathadd MODULEPATH "$_sp_tcl_root/$_sp_sys_type"
 else
-    echo "ERROR: Sourcing spack setup-env.csh requires setting SPACK_ROOT to the root of your spack installation"
+    echo "ERROR: Sourcing spack setup-env.csh requires setting SPACK_ROOT to "
+    echo "       the root of your spack installation."
 endif
diff --git a/share/spack/setup-env.sh b/share/spack/setup-env.sh
index 9f2bb2618c..af18fcd4e1 100755
--- a/share/spack/setup-env.sh
+++ b/share/spack/setup-env.sh
@@ -89,6 +89,42 @@ function spack {
             fi
             return
             ;;
+        "env")
+            _sp_arg=""
+            if [ -n "$1" ]; then
+                _sp_arg="$1"
+                shift
+            fi
+
+            if [ "$_sp_arg" = "-h" ]; then
+                command spack env -h
+            else
+                case $_sp_arg in
+                    activate)
+                        if [ -z "$1" -o "${1#-}" != "$1" ]; then
+                            # no args or does not start with -: just execute
+                            command spack "${args[@]}"
+                        else
+                            # actual call to activate: source the output
+                            eval $(command spack $_sp_flags env activate --sh "$@")
+                        fi
+                        ;;
+                    deactivate)
+                        if [ -n "$1" ]; then
+                            # with args: execute the command
+                            command spack "${args[@]}"
+                        else
+                            # no args: source the output.
+                            eval $(command spack $_sp_flags env deactivate --sh)
+                        fi
+                        ;;
+                    *)
+                        command spack "${args[@]}"
+                        ;;
+                esac
+            fi
+            return
+            ;;
         "use"|"unuse"|"load"|"unload")
             # Shift any other args for use off before parsing spec.
             _sp_subcommand_args=""