Support filename in license headers

Fixes #223.

wpiformat/wpiformat/licenseupdate.py

@@ -19,10 +19,12 @@ def should_process_file(config_file, name):
         return (config_file.is_c_file(name) or config_file.is_cpp_file(name) or
                 name.endswith(".java")) and not license_regex.search(name)
 
-    def __try_regex(self, lines, last_year, license_template):
+    def __try_regex(self, repo_relative_name, lines, last_year,
+                    license_template):
         """Try finding license with regex of license template.
 
         Keyword arguments:
+        repo_relative_name -- repo-relative filename
         lines -- lines of file
         last_year -- last year in copyright range
         license_template -- license_template string
@@ -37,8 +39,8 @@ def __try_regex(self, lines, last_year, license_template):
         license_rgxstr = "^" + linesep.join(license_template)
         license_rgxstr = license_rgxstr.replace("*", r"\*").replace(
             ".", r"\.").replace("(", r"\(").replace(")", r"\)").replace(
-                "{year}",
-                r"(?P<year>[0-9]+)(-[0-9]+)?").replace("{padding}", "[ ]*")
+                "{year}", r"(?P<year>[0-9]+)(-[0-9]+)?").replace(
+                    "{padding}", "[ ]*").replace("{filename}", "")
         license_rgx = regex.compile(license_rgxstr, regex.M)
 
         first_year = last_year
@@ -128,6 +130,8 @@ def __try_string_search(self, lines, last_year, license_template):
     def run_pipeline(self, config_file, name, lines):
         linesep = super().get_linesep(lines)
 
+        repo_relative_name = name[len(Task.get_repo_root()) + 1:]
+
         _, license_template = Config.read_file(
             os.path.dirname(os.path.abspath(name)), ".styleguide-license")
 
@@ -150,7 +154,7 @@ def run_pipeline(self, config_file, name, lines):
             last_year = str(date.today().year)
 
         success, first_year, appendix = self.__try_regex(
-            lines, last_year, license_template)
+            repo_relative_name, lines, last_year, license_template)
         if not success:
             success, first_year, appendix = self.__try_string_search(
                 lines, last_year, license_template)
@@ -167,6 +171,9 @@ def run_pipeline(self, config_file, name, lines):
             # Insert copyright year range
             line = line.replace("{year}", year_range)
 
+            # Insert filename
+            line = line.replace("{filename}", repo_relative_name)
+
             # Insert padding which expands to the 80th column. If there is more
             # than one padding token, the line may contain fewer than 80
             # characters due to rounding during the padding width calculation.