freedreno/registers: Generate copyright comment blurb

Similar to headergen2, the output matches as closely as is reasonable.
The time format and file listing ends up being slightly different but
those would be part of the diffstat when we next update kernel headers
regardless.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27124>

src/freedreno/registers/gen_header.py

@@ -5,6 +5,8 @@ import sys
 import os
 import collections
 import argparse
+import time
+import datetime
 
 class Error(Exception):
 	def __init__(self, message):
@@ -336,6 +338,9 @@ class Parser(object):
 		self.variants = set()
 		self.file = []
 		self.xml_files = []
+		self.copyright_year = None
+		self.authors = []
+		self.license = None
 
 	def error(self, message):
 		parser, filename = self.stack[-1]
@@ -470,6 +475,8 @@ class Parser(object):
 		self.stack.append((parser, filename))
 		parser.StartElementHandler = self.start_element
 		parser.EndElementHandler = self.end_element
+		parser.CharacterDataHandler = self.character_data
+		parser.buffer_text = True
 		parser.ParseFile(file)
 		self.stack.pop()
 		file.close()
@@ -516,6 +523,7 @@ class Parser(object):
 		self.add_all_usages(self.current_reg, usages)
 
 	def start_element(self, name, attrs):
+		self.cdata = ""
 		if name == "import":
 			filename = attrs["file"]
 			self.do_parse(os.path.join(self.path, filename))
@@ -564,6 +572,10 @@ class Parser(object):
 			self.parse_field(attrs["name"], attrs)
 		elif name == "database":
 			self.do_validate(attrs["xsi:schemaLocation"])
+		elif name == "copyright":
+			self.copyright_year = attrs["year"]
+		elif name == "author":
+			self.authors.append(attrs["name"] + " <" + attrs["email"] + "> " + attrs["name"])
 
 	def end_element(self, name):
 		if name == "domain":
@@ -580,6 +592,11 @@ class Parser(object):
 			self.current_array = None
 		elif name == "enum":
 			self.current_enum = None
+		elif name == "license":
+			self.license = self.cdata
+
+	def character_data(self, data):
+		self.cdata += data
 
 	def dump_reg_usages(self):
 		d = collections.defaultdict(list)
@@ -737,6 +754,33 @@ def dump_c(args, guard, func):
 
 	print("#ifndef %s\n#define %s\n" % (guard, guard))
 
+	print("""/* Autogenerated file, DO NOT EDIT manually!
+
+This file was generated by the rules-ng-ng gen_header.py tool in this git repository:
+http://gitlab.freedesktop.org/mesa/mesa/
+git clone https://gitlab.freedesktop.org/mesa/mesa.git
+
+The rules-ng-ng source files this header was generated from are:
+""")
+	maxlen = 0
+	for filepath in p.xml_files:
+		maxlen = max(maxlen, len(filepath))
+	for filepath in p.xml_files:
+		pad = " " * (maxlen - len(filepath))
+		filesize = str(os.path.getsize(filepath))
+		filesize = " " * (7 - len(filesize)) + filesize
+		filetime = time.ctime(os.path.getmtime(filepath))
+		print("- " + filepath + pad + " (" + filesize + " bytes, from " + filetime + ")")
+	if p.copyright_year:
+		current_year = str(datetime.date.today().year)
+		print()
+		print("Copyright (C) %s-%s by the following authors:" % (p.copyright_year, current_year))
+		for author in p.authors:
+			print("- " + author)
+	if p.license:
+		print(p.license)
+	print("*/")
+
 	print()
 	print("#include <assert.h>")
 	print()