utils: checkstyle.py: Turn check() into a class method for all checkers

The check() method of StyleChecker subclasses are instance methods,
while CommitChecker subclasses use class methods. This makes unified
handling of checkers more complicated. Turn the StyleChecker check()
method into a class method, passing it the contents to be checked
directly.

While at it, fix two style issues reported by checkstyle.py.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

utils/checkstyle.py

@@ -598,15 +598,12 @@ class HexValueChecker(StyleChecker):
 
     regex = re.compile(r'\b0[xX][0-9a-fA-F]+\b')
 
-    def __init__(self, content):
-        super().__init__()
-        self.__content = content
-
-    def check(self, line_numbers):
+    @classmethod
+    def check(cls, content, line_numbers):
         issues = []
 
         for line_number in line_numbers:
-            line = self.__content[line_number - 1]
+            line = content[line_number - 1]
             match = HexValueChecker.regex.search(line)
             if not match:
                 continue
@@ -630,15 +627,12 @@ class IncludeChecker(StyleChecker):
                'cwchar', 'cwctype', 'math.h')
     include_regex = re.compile(r'^#include <([a-z.]*)>')
 
-    def __init__(self, content):
-        super().__init__()
-        self.__content = content
-
-    def check(self, line_numbers):
+    @classmethod
+    def check(self, content, line_numbers):
         issues = []
 
         for line_number in line_numbers:
-            line = self.__content[line_number - 1]
+            line = content[line_number - 1]
             match = IncludeChecker.include_regex.match(line)
             if not match:
                 continue
@@ -664,14 +658,11 @@ class LogCategoryChecker(StyleChecker):
     log_regex = re.compile(r'\bLOG\((Debug|Info|Warning|Error|Fatal)\)')
     patterns = ('*.cpp',)
 
-    def __init__(self, content):
-        super().__init__()
-        self.__content = content
-
-    def check(self, line_numbers):
+    @classmethod
+    def check(cls, content, line_numbers):
         issues = []
         for line_number in line_numbers:
-            line = self.__content[line_number-1]
+            line = content[line_number - 1]
             match = LogCategoryChecker.log_regex.search(line)
             if not match:
                 continue
@@ -685,14 +676,11 @@ class LogCategoryChecker(StyleChecker):
 class MesonChecker(StyleChecker):
     patterns = ('meson.build',)
 
-    def __init__(self, content):
-        super().__init__()
-        self.__content = content
-
-    def check(self, line_numbers):
+    @classmethod
+    def check(cls, content, line_numbers):
         issues = []
         for line_number in line_numbers:
-            line = self.__content[line_number-1]
+            line = content[line_number - 1]
             pos = line.find('\t')
             if pos != -1:
                 issues.append(StyleIssue(line_number, [pos, pos], line,
@@ -704,13 +692,10 @@ class ShellChecker(StyleChecker):
     patterns = ('*.sh',)
     results_line_regex = re.compile(r'In - line ([0-9]+):')
 
-    def __init__(self, content):
-        super().__init__()
-        self.__content = content
-
-    def check(self, line_numbers):
+    @classmethod
+    def check(cls, content, line_numbers):
         issues = []
-        data = ''.join(self.__content).encode('utf-8')
+        data = ''.join(content).encode('utf-8')
 
         try:
             ret = subprocess.run(['shellcheck', '-Cnever', '-'],
@@ -934,9 +919,8 @@ def check_file(top_level, commit, filename, checkers):
     # Check for code issues not related to formatting.
     issues = []
     for checker in StyleChecker.instances(filename, checkers):
-        checker = checker(after)
         for hunk in commit_diff:
-            issues += checker.check(hunk.side('to').touched)
+            issues += checker.check(after, hunk.side('to').touched)
 
     # Print the detected issues.
     if len(issues) == 0 and len(formatted_diff) == 0: