diff --git a/lib/spack/env/cc b/lib/spack/env/cc
index df6795c264..c6a09724e9 100755
--- a/lib/spack/env/cc
+++ b/lib/spack/env/cc
@@ -65,7 +65,7 @@ function die {
 }
 
 for param in $parameters; do
-    if [ -z "${!param}" ]; then
+    if [[ -z ${!param} ]]; then
         die "Spack compiler must be run from spack!  Input $param was missing!"
     fi
 done
@@ -78,10 +78,11 @@ done
 # 'command' is set based on the input command to $SPACK_[CC|CXX|F77|F90]
 #
 # 'mode' is set to one of:
+#    cpp     preprocess
 #    cc      compile
+#    as      assemble
 #    ld      link
 #    ccld    compile & link
-#    cpp     preprocessor
 #    vcheck  version check
 #
 command=$(basename "$0")
@@ -131,6 +132,9 @@ if [ -z "$mode" ]; then
         if [ "$arg" = -E ]; then
             mode=cpp
             break
+        elif [ "$arg" = -S ]; then
+            mode=as
+            break
         elif [ "$arg" = -c ]; then
             mode=cc
             break
@@ -146,22 +150,25 @@ fi
 
 # Check that at least one of the real commands was actually selected,
 # otherwise we don't know what to execute.
-if [ -z "$command" ]; then
+if [[ -z $command ]]; then
     die "ERROR: Compiler '$SPACK_COMPILER_SPEC' does not support compiling $language programs."
 fi
 
+if [ "$mode" == vcheck ] ; then
+    exec ${command} "$@"
+fi
+
 # Save original command for debug logging
 input_command="$@"
 args=("$@")
 
-<<<<<<< HEAD
 # Dump parsed values for unit testing if asked for
 if [[ -n $SPACK_TEST_COMMAND ]]; then
 
     #
     # Now do real parsing of the command line args, trying hard to keep
-    # non-rpath linker arguments in the proper order w.r.t. other command
-    # line arguments.  This is important for things like groups.
+    # non-rpath linker arguments in the proper order w.r.t. other command line
+    # arguments.  This is important for things like groups.
     #
     includes=()
     libraries=()
@@ -188,32 +195,44 @@ if [[ -n $SPACK_TEST_COMMAND ]]; then
                 ;;
             -Wl,*)
                 arg="${1#-Wl,}"
-                if [ -z "$arg" ]; then shift; arg="$1"; fi
-                if [[ "$arg" = -rpath=* ]]; then
-                    rpaths+=("${arg#-rpath=}")
-                elif [[ "$arg" = -rpath ]]; then
+                # TODO: Handle multiple -Wl, continuations of -Wl,-rpath
+                if [[ $arg == -rpath=* ]]; then
+                    arg="${arg#-rpath=}"
+                    for rpath in ${arg//,/ }; do
+                        rpaths+=("$rpath")
+                    done
+                elif [[ $arg == -rpath,* ]]; then
+                    arg="${arg#-rpath,}"
+                    for rpath in ${arg//,/ }; do
+                        rpaths+=("$rpath")
+                    done
+                elif [[ $arg == -rpath ]]; then
                     shift; arg="$1"
-                    if [[ "$arg" != -Wl,* ]]; then
+                    if [[ $arg != '-Wl,'* ]]; then
                         die "-Wl,-rpath was not followed by -Wl,*"
                     fi
-                    rpaths+=("${arg#-Wl,}")
+                    arg="${arg#-Wl,}"
+                    for rpath in ${arg//,/ }; do
+                        rpaths+=("$rpath")
+                    done
                 else
                     other_args+=("-Wl,$arg")
                 fi
                 ;;
-            -Xlinker,*)
-                arg="${1#-Xlinker,}"
-                if [ -z "$arg" ]; then shift; arg="$1"; fi
-                if [[ "$arg" = -rpath=* ]]; then
+            -Xlinker)
+                shift; arg="$1";
+                if [[ $arg = -rpath=* ]]; then
                     rpaths+=("${arg#-rpath=}")
-                elif [[ "$arg" = -rpath ]]; then
+                elif [[ $arg = -rpath ]]; then
                     shift; arg="$1"
-                    if [[ "$arg" != -Xlinker,* ]]; then
-                        die "-Xlinker,-rpath was not followed by -Xlinker,*"
+                    if [[ $arg != -Xlinker ]]; then
+                        die "-Xlinker -rpath was not followed by -Xlinker <arg>"
                     fi
-                    rpaths+=("${arg#-Xlinker,}")
+                    shift; arg="$1"
+                    rpaths+=("$arg")
                 else
-                    other_args+=("-Xlinker,$arg")
+                    other_args+=("-Xlinker")
+                    other_args+=("$arg")
                 fi
                 ;;
             *)
@@ -222,88 +241,6 @@ if [[ -n $SPACK_TEST_COMMAND ]]; then
         esac
         shift
     done
-=======
-if [ "$mode" == vcheck ] ; then
-    exec ${command} "$@"
-fi
-
-#
-# Now do real parsing of the command line args, trying hard to keep
-# non-rpath linker arguments in the proper order w.r.t. other command
-# line arguments.  This is important for things like groups.
-#
-includes=()
-libraries=()
-libs=()
-rpaths=()
-other_args=()
-
-while [ -n "$1" ]; do
-    case "$1" in
-        -I*)
-            arg="${1#-I}"
-            if [ -z "$arg" ]; then shift; arg="$1"; fi
-            includes+=("$arg")
-            ;;
-        -L*)
-            arg="${1#-L}"
-            if [ -z "$arg" ]; then shift; arg="$1"; fi
-            libraries+=("$arg")
-            ;;
-        -l*)
-            arg="${1#-l}"
-            if [ -z "$arg" ]; then shift; arg="$1"; fi
-            libs+=("$arg")
-            ;;
-        -Wl,*)
-            arg="${1#-Wl,}"
-            # TODO: Handle multiple -Wl, continuations of -Wl,-rpath
-            if [[ $arg == -rpath=* ]]; then
-                arg="${arg#-rpath=}"
-                for rpath in ${arg//,/ }; do
-                    rpaths+=("$rpath")
-                done
-            elif [[ $arg == -rpath,* ]]; then
-                arg="${arg#-rpath,}"
-                for rpath in ${arg//,/ }; do
-                    rpaths+=("$rpath")
-                done
-            elif [[ $arg == -rpath ]]; then
-                shift; arg="$1"
-                if [[ $arg != '-Wl,'* ]]; then
-                    die "-Wl,-rpath was not followed by -Wl,*"
-                fi
-                arg="${arg#-Wl,}"
-                for rpath in ${arg//,/ }; do
-                    rpaths+=("$rpath")
-                done
-            else
-                other_args+=("-Wl,$arg")
-            fi
-            ;;
-        -Xlinker)
-            shift; arg="$1";
-            if [[ $arg = -rpath=* ]]; then
-                rpaths+=("${arg#-rpath=}")
-            elif [[ $arg = -rpath ]]; then
-                shift; arg="$1"
-                if [[ $arg != -Xlinker ]]; then
-                    die "-Xlinker -rpath was not followed by -Xlinker <arg>"
-                fi
-                shift; arg="$1"
-                rpaths+=("$arg")
-            else
-                other_args+=("-Xlinker")
-                other_args+=("$arg")
-            fi
-            ;;
-        *)
-            other_args+=("$1")
-            ;;
-    esac
-    shift
-done
->>>>>>> develop
 
     IFS=$'\n'
     case "$SPACK_TEST_COMMAND" in
@@ -329,8 +266,8 @@ done
             echo "${other_args[*]}"
             ;;
         *)
-            echo "ERROR: Unknown test command"
-            exit 1 ;;
+            die "ERROR: Unknown test command"
+            ;;
     esac
     exit
 fi
@@ -338,11 +275,14 @@ fi
 # Read spack dependencies from the path environment variable
 IFS=':' read -ra deps <<< "$SPACK_DEPENDENCIES"
 for dep in "${deps[@]}"; do
-    if [ -d "$dep/include" ]; then
-        args=("-I$dep/include" "${args[@]}")
+    if [[ -d $dep/include ]]; then
+        if [[ $mode = cpp || $mode = cc || $mode = as || $mode = ccld ]]; then
+            args=("-I$dep/include" "${args[@]}")
+        fi
     fi
 
-    if [ -d "$dep/lib" ]; then
+    if [[ -d $dep/lib ]]; then
+        # libraries+=("$dep/lib")
         if [[ $mode = ccld ]]; then
             args=("-L$dep/lib" "-Wl,-rpath,$dep/lib" "${args[@]}")
         elif [[ $mode = ld ]]; then
@@ -350,7 +290,7 @@ for dep in "${deps[@]}"; do
         fi
     fi
 
-    if [ -d "$dep/lib64" ]; then
+    if [[ -d $dep/lib64 ]]; then
         # libraries+=("$dep/lib64")
         if [[ $mode = ccld ]]; then
             args=("-L$dep/lib" "-Wl,-rpath,$dep/lib" "${args[@]}")
@@ -362,8 +302,18 @@ done
 
 # Include all -L's and prefix/whatever dirs in rpath
 if [[ $mode = ccld ]]; then
+    # for dir in "${libraries[@]}"; do
+    #     if [[ dir = $SPACK_INSTALL* ]]; then
+    #         args=("-Wl,-rpath,$dir" "${args[@]}")
+    #     fi
+    # done
     args=("-Wl,-rpath,$SPACK_PREFIX/lib" "-Wl,-rpath,$SPACK_PREFIX/lib64" "${args[@]}")
 elif [[ $mode = ld ]]; then
+    # for dir in "${libraries[@]}"; do
+    #     if [[ dir = $SPACK_INSTALL* ]]; then
+    #         args=("-rpath" "$dir" "${args[@]}")
+    #     fi
+    # done
     args=("-rpath" "$SPACK_PREFIX/lib" "-rpath" "$SPACK_PREFIX/lib64" "${args[@]}")
 fi
 
@@ -385,28 +335,23 @@ PATH=""
 for dir in "${env_path[@]}"; do
     remove=""
     for rm_dir in "${spack_env_dirs[@]}"; do
-        if [ "$dir" = "$rm_dir" ]; then remove=True; fi
+        if [[ $dir = $rm_dir ]]; then remove=True; fi
     done
-    if [ -z "$remove" ]; then
-        if [ -z "$PATH" ]; then
-            PATH="$dir"
-        else
-            PATH="$PATH:$dir"
-        fi
+    if [[ -z $remove ]]; then
+        PATH="${PATH:+$PATH:}$dir"
     fi
 done
 export PATH
 
-full_command=("$command")
-full_command+=("${args[@]}")
+full_command=("$command" "${args[@]}")
 
 #
 # Write the input and output commands to debug logs if it's asked for.
 #
-if [ "$SPACK_DEBUG" = "TRUE" ]; then
+if [[ $SPACK_DEBUG = TRUE ]]; then
     input_log="$SPACK_DEBUG_LOG_DIR/spack-cc-$SPACK_SHORT_SPEC.in.log"
     output_log="$SPACK_DEBUG_LOG_DIR/spack-cc-$SPACK_SHORT_SPEC.out.log"
-    echo "$input_command"     >> $input_log
+    echo "$input_command" >> $input_log
     echo "$mode       ${full_command[@]}" >> $output_log
 fi