1 files changed, 52 insertions, 27 deletions

diff --git a/share/spack/setup-env.csh b/share/spack/setup-env.csh
index 1985e023de..b70036456d 100755
--- a/share/spack/setup-env.csh
+++ b/share/spack/setup-env.csh
@@ -3,14 +3,12 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
-
 #
 # This file is part of Spack and sets up the spack environment for
 # csh and tcsh.  This includes environment modules and lmod support, and
 # it also puts spack in your path.  Source it like this:
 #
-#    setenv SPACK_ROOT /path/to/spack
-#    source $SPACK_ROOT/share/spack/setup-env.csh
+#    source /path/to/spack/share/spack/setup-env.csh
 #
 
 # prevent infinite recursion when spack shells out (e.g., on cray for modules)
@@ -19,32 +17,59 @@ if ($?_sp_initializing) then
 endif
 setenv _sp_initializing true
 
-if ($?SPACK_ROOT) then
-    set _spack_source_file = $SPACK_ROOT/share/spack/setup-env.csh
-    set _spack_share_dir   = $SPACK_ROOT/share/spack
-
-    # Command aliases point at separate source files
-    alias spack          'set _sp_args = (\!*); source $_spack_share_dir/csh/spack.csh'
-    alias spacktivate    'spack env activate'
-    alias _spack_pathadd 'set _pa_args = (\!*) && source $_spack_share_dir/csh/pathadd.csh'
-
-    # Set variables needed by this script
-    _spack_pathadd PATH "$SPACK_ROOT/bin"
-    eval `spack --print-shell-vars csh`
-
-    # Set up module search paths in the user environment
-    set tcl_roots = `echo $_sp_tcl_roots:q | sed 's/:/ /g'`
-    set compatible_sys_types = `echo $_sp_compatible_sys_types:q | sed 's/:/ /g'`
-    foreach tcl_root ($tcl_roots:q)
-        foreach systype ($compatible_sys_types:q)
-            _spack_pathadd MODULEPATH "$tcl_root/$systype"
-        end
-    end
+# If SPACK_ROOT is not set, we'll try to find it ourselves.
+# csh/tcsh don't have a built-in way to do this, but both keep files
+# they are sourcing open. We use /proc on linux and lsof on macs to
+# find this script's full path in the current process's open files.
+if (! $?SPACK_ROOT) then
+    # figure out a command to list open files
+    if (-d /proc/$$/fd) then
+        set _sp_lsof = "ls -l /proc/$$/fd"
+    else
+        which lsof > /dev/null
+        if ($? == 0) then
+            set _sp_lsof = "lsof -p $$"
+        endif
+    endif
+
+    # filter this script out of list of open files
+    if ( $?_sp_lsof ) then
+        set _sp_source_file = `$_sp_lsof | sed -e 's/^[^/]*//' | grep "/setup-env.csh"`
+    endif
+
+    # This script is in $SPACK_ROOT/share/spack; get the root with dirname
+    if ($?_sp_source_file) then
+        set _sp_share_spack = `dirname "$_sp_source_file"`
+        set _sp_share = `dirname "$_sp_share_spack"`
+        setenv SPACK_ROOT `dirname "$_sp_share"`
+    endif
 
-else
-    echo "ERROR: Sourcing spack setup-env.csh requires setting SPACK_ROOT to "
-    echo "       the root of your spack installation."
+    if (! $?SPACK_ROOT) then
+        echo "==> Error: setup-env.csh couldn't figure out where spack lives."
+        echo "    Set SPACK_ROOT to the root of your spack installation and try again."
+        exit 1
+    endif
 endif
 
+# Command aliases point at separate source files
+set _spack_source_file = $SPACK_ROOT/share/spack/setup-env.csh
+set _spack_share_dir = $SPACK_ROOT/share/spack
+alias spack          'set _sp_args = (\!*); source $_spack_share_dir/csh/spack.csh'
+alias spacktivate    'spack env activate'
+alias _spack_pathadd 'set _pa_args = (\!*) && source $_spack_share_dir/csh/pathadd.csh'
+
+# Set variables needed by this script
+_spack_pathadd PATH "$SPACK_ROOT/bin"
+eval `spack --print-shell-vars csh`
+
+# Set up module search paths in the user environment
+set tcl_roots = `echo $_sp_tcl_roots:q | sed 's/:/ /g'`
+set compatible_sys_types = `echo $_sp_compatible_sys_types:q | sed 's/:/ /g'`
+foreach tcl_root ($tcl_roots:q)
+    foreach systype ($compatible_sys_types:q)
+        _spack_pathadd MODULEPATH "$tcl_root/$systype"
+    end
+end
+
 # done: unset sentinel variable as we're no longer initializing
 unsetenv _sp_initializing