linux: autopatch: Find bytecode and update patch.sh

Have a two-script workflow where one focuses on finding the bytecode in
the driver files, and the other focuses on updating patch.sh using the
newly found bytecode or a previously existing one.

Signed-off-by: Jai Luthra <me@jailuthra.in>

tools/autopatch/update_patch.sh

@@ -0,0 +1,87 @@
+#!/bin/bash
+
+set -euo pipefail
+
+print_usage() { printf '
+SYNOPSIS
+   update_patch.sh -f PATCH_FILE [-v VERSION [-o OLD_VERSION] | -b PATCHSTR | -h]
+
+DESCRIPTION
+    Update the patch for Nvidia NVENC or NVFBC drivers for a new version
+
+    -f PATCH_FILE               The file (patch.sh/patch-fbc.sh) that should be updated
+    -v VERSION                  Driver version (by default copies latest existing patch)
+    -o OLD_VERSION              Copy patch string from this older driver version
+    -b PATCHSTR                 Append PATCHSTR to the patch_list
+    -h                          Print help
+'
+}
+
+opmode="copy"
+
+while getopts 'hf:v:o:b:' flag; do
+    case "${flag}" in
+        f) patch_file="$OPTARG" ;;
+        v) new_version="$OPTARG" ;;
+        o) old_version="$OPTARG" ;;
+        b) opmode="new" ; patch_string="$OPTARG" ;;
+        h) opmode="help" ;;
+        *) echo "Incorrect option specified in command line" ; exit 2 ;;
+    esac
+done
+
+
+get_last_line() {
+    if [[ -v old_version ]]; then
+        # Find old patch line
+        last=$(grep -n "\s.*\[\"$old_version\"\]='.*/g\?'" $patch_file | tail -1)
+    else
+        # Find the latest patch line
+        last=$(grep -n "\s.*\[\".*\"\]='.*/g\?'" $patch_file | tail -1)
+    fi
+    echo $last
+}
+
+get_last_line_number() {
+    last=$1
+
+    # Find the line number to insert at
+    line=$(cut -d : -f 1 <<<"$last")
+    line=$((line + 1))
+
+    echo $line
+}
+
+copy_patch() {
+    last=$(get_last_line)
+    line=$(get_last_line_number $last)
+
+    # Use the same bytecode, and escape it
+    bytecode=$(cut -d = -f 2 <<<"$last")
+    bytecode=$(printf '%s\n' "$bytecode" | sed -e 's/[]\/$*.^[]/\\&/g');
+
+    # Insert bytecode
+    sed -i "${line} i \ \ \ \ [\"${new_version}\"]=${bytecode}" $patch_file
+
+    echo "Successfully inserted bytecode for $new_version"
+}
+
+apply_new_patch() {
+    line=$(get_last_line_number $(get_last_line))
+
+    # Escape the patch string
+    bytecode=$(printf '%s\n' "$patch_string" | sed -e 's/[]\/$*.^[]/\\&/g');
+
+    # Insert it at the end
+    sed -i "${line} i \ \ \ \ ${bytecode}" $patch_file
+
+    echo "Successfully inserted $patch_string"
+}
+
+case "${opmode}" in
+    help) print_usage ; exit 2 ;;
+    copy) copy_patch ;;
+    new) apply_new_patch ;;
+    *) echo "Incorrect combination of flags. Use option -h to get help."
+       exit 2 ;;
+esac