diff --git a/src/fparse-llvm.in b/src/fparse-llvm.in
index ac398ca..9712a7c 100755
--- a/src/fparse-llvm.in
+++ b/src/fparse-llvm.in
@@ -56,22 +56,105 @@ if [[ $# -eq 0 ]]; then
     exit 1
 fi
 
+# Set a whitelist of flags that can be passed to the flang frontend plugin
+# This is where libtooling for flang could help
+# List derived from output of `flang-new -fc1 -help`
+declare -a -r _WHITELISTED_FLAGS=( 
+  -cpp
+  -dM
+  -E
+  -falternative-parameter-statement
+  -fbackslash
+  -fcolor-diagnostics
+  -ffixed-form
+  -ffree-form
+  -fimplicit-none
+  -flogical-abbreviations
+  -fno-reformat
+  -fopenacc
+  -fopenmp-is-target-device
+  -fopenmp-target-debug
+  -fopenmp
+  -fsyntax-only
+  -funderscoring
+  -fxor-operator
+  -help
+  -init-only
+  -nocpp
+  -pedantic
+  -pthread
+  -P
+  -save-temps
+  -S
+  -version
+  -w
+  "-ffixed-line-length=.*"
+  "-finput-charset=.*"
+  "-fopenmp-version=.*"
+  "-save-temps=.*"
+  "-std=.*"
+)
+_WHITELISTED_REGEX="(${_WHITELISTED_FLAGS[0]})"
+# Loop over the secend element of _WHITELISTED_FLAGS to the end and add them to the regex
+for flag in "${_WHITELISTED_FLAGS[@]:1}"; do
+    _WHITELISTED_REGEX="${_WHITELISTED_REGEX}|(${flag})"
+done
+declare -r -a _BLACKLISTED_FLAGS=(
+    "-Wl,.*"
+    "--"
+)
+_BLACKLISTED_REGEX="(${_BLACKLISTED_FLAGS[0]})"
+for flag in "${_BLACKLISTED_FLAGS[@]:1}"; do
+    _BLACKLISTED_REGEX="${_BLACKLISTED_REGEX}|(${flag})"
+done
+declare -r -a _WHITELISTED_FLAGS_WARNING_ARG=(
+    "-W[^l].*"
+)
+_WHITELISTED_WARNING_REGEX="(${_WHITELISTED_FLAGS_WARNING_ARG[0]})"
+for flag in "${_WHITELISTED_FLAGS_WARNING_ARG[@]:1}"; do
+    _WHITELISTED_WARNING_REGEX="${_WHITELISTED_WARNING_REGEX}|(${flag})"
+done
+declare -r -a _WHITELISTED_FLAGS_MAYBE_SPACE_ARG=(
+    "-I"
+    "-J"
+    "-D"
+    "-U"
+)
+for flag in "${_WHITELISTED_FLAGS_MAYBE_SPACE_ARG[@]}"; do
+    _WHITELISTED_REGEX="${_WHITELISTED_REGEX}|(${flag}.+)"
+done
+
+declare -r -a _WHITELISTED_FLAGS_YES_SPACE_ARG=(
+    "-module-dir"
+    "-module-suffix"
+    "-x"
+)
+_WHITELISTED_OPT_ARG_REGEX="(${_WHITELISTED_FLAGS_YES_SPACE_ARG[0]})"
+for flag in "${_WHITELISTED_FLAGS_YES_SPACE_ARG[@]:1}"; do
+    _WHITELISTED_OPT_ARG_REGEX="${_WHITELISTED_OPT_ARG_REGEX}|(${flag})"
+done
+for flag in "${_WHITELISTED_FLAGS_MAYBE_SPACE_ARG[@]}"; do
+    _WHITELISTED_OPT_ARG_REGEX="${_WHITELISTED_OPT_ARG_REGEX}|(${flag})"
+done
+
+# echo "WHITELISTED_REGEX: ${_WHITELISTED_REGEX}"
+# echo "BLACKLISTED_REGEX: ${_BLACKLISTED_REGEX}"
+# echo "WHITELISTED_WARNING_REGEX: ${_WHITELISTED_WARNING_REGEX}"
+# echo "WHITELISTED_OPT_ARG_REGEX: ${_WHITELISTED_OPT_ARG_REGEX}"
+
+
 # Loop over the arguments and check for the output file -o flag and it's argument
 # If found, set the output file name to the argument following the -o flag and remove the -o flag and argument from the argument list
 # If not found, set the output file name to the first argument with a .inst extension
 #echo "Passed command line arguments: $*"
 
 args=()
+original_args=("$@")
 expecting_output_file=false
-forward_remaining_args=false
+expecting_arg_to_forward=false
 show=false
 for arg in "$@"; do
     #echo "working on arg: $arg"
-    if [[ $forward_remaining_args == true ]]; then
-        args+=("${@}")
-        #echo "args remaining: $*"
-        break
-    fi
     if [[ $arg == -h ]]; then
         usage
         exit 0
@@ -80,13 +163,14 @@ for arg in "$@"; do
         expecting_output_file=false
         shift || true
         #echo "args remaining: $*"
-    elif [[ $arg == -o || $arg == --tau_output ]]; then
+    elif $expecting_arg_to_forward; then
+        args+=("$arg")
+        expecting_arg_to_forward=false
         shift
-        expecting_output_file=true
         #echo "args remaining: $*"
-    elif [[ $arg == -o* ]]; then
-        output_file="${arg#-o}"
-        shift || true
+    elif [[ $arg == --tau_output ]]; then
+        shift
+        expecting_output_file=true
         #echo "args remaining: $*"
     elif [[ $arg == --tau_output=* ]]; then
         output_file="${arg#--tau_output=}"
@@ -105,32 +189,29 @@ for arg in "$@"; do
         shift || true
         #echo "args remaining: $*"
     # Begin sanitizing options/flags that cause the frontend plugin to throw an error
-    elif [[ $arg == -- ]]; then
-        shift
-        #forward_remaining_args=true
-        #echo "args remaining: $*"
-    elif [[ $arg == -fPIC ]]; then
-        shift || true
-        #echo "args remaining: $*"
-    elif [[ $arg == -g ]]; then
-        shift || true
-        #echo "args remaining: $*"
-    elif [[ $arg == -c ]]; then
+    elif [[ ${arg:-} =~ $_BLACKLISTED_REGEX ]]; then
         shift || true
-        #echo "args remaining: $*"
-    elif [[ $arg == -s ]]; then
+        echo "Removed blacklisted flag: $arg"
+    elif [[ "${arg:-}" =~ $_WHITELISTED_WARNING_REGEX ]]; then
+        # Only safe to do after ensuring -Wl,* blacklisted flag is removed
+        if [[ "${arg:-}" == -Werror ]]; then
+            args+=("$arg")
+        fi
+        # Flang frontend oesn't (yet) support -Wall, -Wextra, etc. only -Werror, so throw others away
         shift || true
-        #echo "args remaining: $*"
-    elif [[ $arg == -shared || $arg == -static ]]; then
+        #echo "Added whitelisted warning flag: $arg"
+    elif [[ ${arg:-} =~ ${_WHITELISTED_REGEX} ]]; then
+        args+=("$arg")
         shift || true
-        #echo "args remaining: $*"
-    elif [[ $arg == -Wl,* ]]; then
+        #echo "Added whitelisted flag: $arg"
+    elif [[ ${arg:-} =~ ${_WHITELISTED_OPT_ARG_REGEX} ]]; then
+        args+=("$arg")
+        expecting_arg_to_forward=true
         shift || true
-        #echo "args remaining: $*"
-    elif [[ -n ${arg:-} ]]; then
-        args+=("${arg}")
+        #echo "Added whitelisted flag with argument: $arg"
+    else
+        echo "Removed unknown flag: $arg"
         shift || true
-        #echo "args remaining: $*"
     fi
 done