lexers: Add a Makefile lexer

Author: fstachura

elixir/lexers/__main__.py

@@ -19,6 +19,8 @@
             lexer = lexers.KconfigLexer(f.read())
         elif filename.endswith(('.s', '.S')):
             lexer = lexers.GasLexer(f.read())
+        elif filename.endswith('Makefile'):
+            lexer = lexers.MakefileLexer(f.read())
         else:
             raise Exception("no lexer for filetype")
 

elixir/lexers/lexers.py

@@ -362,3 +362,34 @@ def lex(self):
 
         return simple_lexer(rules, self.code)
 
+
+# https://www.gnu.org/software/make/manual/make.html
+class MakefileLexer:
+    # https://pubs.opengroup.org/onlinepubs/007904975/utilities/make.html
+
+    # NOTE same as in KConfig, we only care about screaming case names
+    make_identifier = r'[A-Z0-9_]+'
+    make_minor_identifier = r'[a-zA-Z0-9_][a-zA-Z0-9-_]*'
+    make_variable = r'(\$\([a-zA-Z0-9_-]\)|\$\{[a-zA-Z0-9_-]\})'
+    make_single_quote_string = r"'*?'"
+    make_string = f'(({ make_single_quote_string })|({ shared.double_quote_string_with_escapes }))'
+    make_escape = r'\\[#"\']'
+    make_punctuation = r'[~\\`\[\](){}<>.,:;|%$^@&?!+*/=-]'
+    make_comment = r'(?<!\\)#(\\\s*\n|[^\n])*\n'
+
+    rules = [
+        (shared.whitespace, TokenType.WHITESPACE),
+        (make_escape, TokenType.PUNCTUATION),
+        (make_comment, TokenType.COMMENT),
+        (make_string, TokenType.STRING),
+        (make_identifier, TokenType.IDENTIFIER),
+        (make_minor_identifier, TokenType.SPECIAL),
+        (make_punctuation, TokenType.PUNCTUATION),
+    ]
+
+    def __init__(self, code):
+        self.code = code
+
+    def lex(self):
+        return simple_lexer(self.rules, self.code)
+