Add helper script to check and update copyright header.

From: https://github.com/ROCm/rocm-examples/blob/develop/Scripts/CopyrightDate/check_copyright.sh

scripts/check_copyright.sh

@@ -0,0 +1,223 @@
+#!/usr/bin/env bash
+
+# Start of configuration
+preamble="Copyright +(\([cC]\) +)?"
+postamble=",? +Advanced +Micro +Devices, +Inc\."
+find_pattern="$preamble([0-9]{4}-)?[0-9]{4}$postamble"
+# printf format string, receives the current year as a parameter
+uptodate_pattern="$preamble([0-9]{4}-)?%d$postamble"
+# <pattern>/<replacement> interpreted with sed syntax, also passed to printf
+# printf interprets '\' escape sequences so they must be escaped
+# The capture groups are as follows:
+#   - \1 is the whole preamble text
+#   - \3 is the start year, \2 is skipped because it is used for an optional part of the preamble
+#   - \5 is the end of the copyright statement after the end year, \4 would be the original end year
+#     as written in the file, it is replaced by the current year instead.
+replace_pattern="($preamble)([0-9]{4})(-[0-9]{4})?($postamble)/\\\1\\\3-%d\\\5"
+# End of configuration
+
+print_help() { printf -- \
+"\033[36musuage\033[0m: \033[33mcheck_year.sh [-h] [-u] [-a] [-d <SHA>] [-k] [-v]\033[0m
+\033[36mdescription\033[0m: Checks for if the copyright year in the staged files is up to date and displays the files with out-of-date copyright statements. Exits with '0' if successful and with '1' if something is out of date.
+\033[36moptions\033[0m:
+  \033[34m-h\033[0m       Displays this message.
+  \033[34m-u\033[0m       Automatically updates the copyright year
+  \033[34m-a\033[0m       Automatically applies applies the changes to current staging environment. Implies '-u' and '-c'.
+  \033[34m-c\033[0m       Compare files to the index instead of the working tree.
+  \033[34m-d <SHA>\033[0m Compare using the diff of a hash.
+  \033[34m-k\033[0m       Compare using the fork point: where this branch and 'remotes/origin/HEAD' diverge.
+  \033[34m-q\033[0m       Suppress updates about progress.
+  \033[34m-v\033[0m       Verbose output.
+Use '\033[33mgit config --local hooks.updateCopyright <true|false>\033[0m' to automatically apply copyright changes on commit.
+"
+}
+
+# argument parsing
+apply=false
+update=false
+verbose=false
+forkdiff=false
+quiet=false
+cached=false
+
+while getopts "auhvkqcd:" arg; do
+    case $arg in
+        a) update=true;apply=true;cached=true;;
+        u) update=true;;
+        v) verbose=true;;
+        k) forkdiff=true;;
+        q) quiet=true;;
+        c) cached=true;;
+        d) diff_hash=${OPTARG};;
+        h) print_help; exit;;
+        *) print help; exit 1;;
+    esac
+done
+
+# If set, check all files changed since the fork point
+if $forkdiff; then
+    branch="$(git rev-parse --abbrev-ref HEAD)"
+    remote="$(git config --local --get "branch.$branch.remote" || echo 'origin')"
+    source_commit="remotes/$remote/HEAD"
+
+    # don't use fork-point for finding fork point (lol)
+    # see: https://stackoverflow.com/a/53981615
+    diff_hash="$(git merge-base "$source_commit" "$branch")"
+fi
+
+if [ -n "${diff_hash}" ]; then
+    $verbose && printf -- "Using base commit: %s\n" "${diff_hash}"
+else
+    diff_hash="HEAD"
+fi
+
+# Current year
+year="$(date +%Y)"
+
+# Enable rename detection with full matches only, this skips copyright checks for file name only
+# changes.
+diff_opts=(-z --name-only '--diff-filter=MA' '--find-renames=100%')
+git_grep_opts=(-z --extended-regexp --ignore-case --no-recursive -I)
+if $cached; then
+    diff_opts+=(--cached)
+    git_grep_opts+=(--cached)
+fi
+
+! $quiet && printf -- "Checking if copyright statements are up-to-date... "
+mapfile -d $'\0' changed_files < <(git diff-index "${diff_opts[@]}" "$diff_hash" | LANG=C.UTF-8 sort -z)
+
+if ! (( ${#changed_files[@]} )); then
+    ! $quiet && printf -- "\033[32mDone!\033[0m\n"
+    $verbose && printf -- "\033[36mNo changed files found.\033[0m\n"
+    exit 0
+fi;
+
+mapfile -d $'\0' found_copyright < <(                                      \
+    git grep "${git_grep_opts[@]}" --files-with-matches -e "$find_pattern" \
+        -- "${changed_files[@]}" |                                         \
+    LANG=C.UTF-8 sort -z)
+
+outdated_copyright=()
+if (( ${#found_copyright[@]} )); then
+    # uptodate_pattern variable holds the format string using it as such is intentional
+    # shellcheck disable=SC2059
+    printf -v uptodate_pattern -- "$uptodate_pattern" "$year"
+    mapfile -d $'\0' outdated_copyright < <(                                        \
+        git grep "${git_grep_opts[@]}" --files-without-match -e "$uptodate_pattern" \
+            -- "${found_copyright[@]}" |                                            \
+        LANG=C.UTF-8 sort -z)
+fi
+
+! $quiet && printf -- "\033[32mDone!\033[0m\n"
+if $verbose; then
+    # Compute the files that don't have a copyright as the set difference of
+    # `changed_files and `found_copyright`
+    mapfile -d $'\0' notfound_copyright < <(                                   \
+        printf -- '%s\0' "${changed_files[@]}" |                               \
+        LANG=C.UTF-8 comm -z -23 - <(printf -- '%s\0' "${found_copyright[@]}"))
+
+    if (( ${#notfound_copyright[@]} )); then
+        printf -- "\033[36mCouldn't find a copyright statement in %d file(s):\033[0m\n" \
+            "${#notfound_copyright[@]}"
+        printf -- '  - %q\n' "${notfound_copyright[@]}"
+    fi
+
+    # Similarly the up-to-date files are the difference of `found_copyright` and `outdated_copyright`
+    mapfile -d $'\0' uptodate_copyright < <(                                       \
+        printf -- '%s\0' "${found_copyright[@]}" |                                 \
+        LANG=C.UTF-8 comm -z -23 - <(printf -- '%s\0' "${outdated_copyright[@]}"))
+
+    if (( ${#uptodate_copyright[@]} )); then
+        printf -- "\033[36mThe copyright statement was already up to date in %d file(s):\033[0m\n" \
+            "${#uptodate_copyright[@]}"
+        printf -- '  - %q\n' "${uptodate_copyright[@]}"
+    fi
+fi
+
+if ! (( ${#outdated_copyright[@]} )); then
+    exit 0
+fi
+
+printf -- \
+"\033[31m==== COPYRIGHT OUT OF DATE ====\033[0m
+\033[36m%d file(s) need(s) to be updated:\033[0m\n" "${#outdated_copyright[@]}"
+printf -- '  - %q\n' "${outdated_copyright[@]}"
+
+# If we don't need to update, we early exit.
+if ! $update; then
+    printf -- \
+"\nRun '\033[33m%s -u\033[0m' to update the copyright statement(s). See '-h' for more info,
+or set '\033[33mgit config --local hooks.updateCopyright true\033[0m' to automatically update copyrights when committing.\n" \
+"${BASH_SOURCE[0]}"
+    exit 1
+fi
+
+if $apply; then
+    ! $quiet && printf -- "Updating copyrights and staging changes... "
+else
+    ! $quiet && printf -- "Updating copyrights... "
+fi
+
+# replace_pattern variable holds a format string, using it as such is intentional
+# shellcheck disable=SC2059
+printf -v replace_pattern -- "$replace_pattern" "$year"
+# Just update the files in place if only touching the working-tree
+if ! $apply; then
+    sed --regexp-extended --separate "s/$replace_pattern/g" -i "${outdated_copyright[@]}"
+    printf -- "\033[32mDone!\033[0m\n"
+    exit 0
+fi
+
+generate_patch() {
+    # Sed command to create a hunk for a copyright statement fix
+    # expects input to be line number then copyright statement on the next line
+    to_hunk_cmd="{# Print hunk header, move to the next line
+                  s/.+/@@ -&,1 +&,1 @@/;n
+                  # Print removed line by prepending '-' to it
+                  ;s/^/-/;p
+                  # Print added line, replace the '-' with '+' and replace the copyright statement
+                  s/^-/+/;s/$replace_pattern/g}"
+
+    # Run file-names through git ls-files, just to get a (possibly) quoted name for each
+    mapfile -t -d $'\n' quoted_files < <(git ls-files --cached -- "${outdated_copyright[@]}")
+    for ((i = 0;i < ${#outdated_copyright[@]}; i++)); do
+        file="${outdated_copyright["$i"]}"
+        quoted="${quoted_files["$i"]}"
+        # Drop the quote from the start and end (to avoid quoting twice)
+        escaped="${quoted#\"}"; escaped="${escaped%\"}"
+        a="\"a/$escaped\""
+        b="\"b/$escaped\""
+
+        printf -- "diff --git %s %s\n--- %s\n+++ %s\n" "$a" "$b" "$a" "$b"
+
+        # Print line number and line for each line with a copyright statement
+        git cat-file blob ":$file" |                               \
+            sed --quiet --regexp-extended "/$find_pattern/{=;p}" | \
+            sed --regexp-extended "$to_hunk_cmd"
+    done
+}
+
+patch_file="$(git rev-parse --git-dir)/copyright-fix.patch"
+generate_patch > "$patch_file"
+
+# Cleanup patch file when the script exits
+finish () {
+    rm -f "$patch_file"
+}
+# The trap will be invoked whenever the script exits, even due to a signal, this is a bash only
+# feature
+trap finish EXIT
+
+if ! git apply --unidiff-zero < "$patch_file"; then
+    printf -- "\033[31mFailed to apply changes to working tree.
+Perhaps the fix is already applied, but not yet staged?\n\033[0m"
+    exit 1
+fi
+
+if ! git apply --cached --unidiff-zero < "$patch_file"; then
+    printf -- "\033[31mFailed to apply change to the index.\n\033[0m"
+    exit 1
+fi
+
+! $quiet && printf -- "\033[32mDone!\033[0m\n"
+exit 0