Let build_grammars ensure that generated lexer/parser are on sys.path

grammarinator/parse.py

@@ -9,7 +9,6 @@
 import json
 import os
 import shutil
-import sys
 
 from argparse import ArgumentParser
 from math import inf
@@ -55,9 +54,6 @@ def __init__(self, grammars, parser_dir,
         self.parser_dir = parser_dir
         os.makedirs(self.parser_dir, exist_ok=True)
 
-        if self.parser_dir not in sys.path:
-            sys.path.append(self.parser_dir)
-
         grammars = grammars if isinstance(grammars, list) else json.loads(grammars)
         for i, grammar in enumerate(grammars):
             shutil.copy(grammar, self.parser_dir)

grammarinator/parser_builder.py

@@ -1,11 +1,12 @@
-# Copyright (c) 2017-2019 Renata Hodovan, Akos Kiss.
+# Copyright (c) 2017-2020 Renata Hodovan, Akos Kiss.
 #
 # Licensed under the BSD 3-Clause License
 # <LICENSE.rst or https://opensource.org/licenses/BSD-3-Clause>.
 # This file may not be copied, modified, or distributed except
 # according to those terms.
 
 import logging
+import sys
 
 from os import listdir
 from os.path import basename, commonprefix, split, splitext
@@ -71,6 +72,10 @@ def file_endswith(end_pattern):
         # The name of the generated listeners differs if Python or other language target is used.
         listener = file_endswith('{listener_format}.{ext}'.format(listener_format=languages['python']['listener_format'], ext=languages['python']['ext']))
 
+        # Add the path of the built lexer and parser to the Python path to be available for importing.
+        if out not in sys.path:
+            sys.path.append(out)
+
         return (getattr(__import__(x, globals(), locals(), [x], 0), x) for x in [lexer, parser, listener])
     except Exception as e:
         logger.error('Exception while loading parser modules', exc_info=e)

grammarinator/process.py

@@ -6,7 +6,6 @@
 # according to those terms.
 
 import re
-import sys
 
 from argparse import ArgumentParser
 from collections import defaultdict
@@ -550,9 +549,6 @@ def __init__(self, work_dir=None, antlr=default_antlr_path):
 
         antlr_dir = join(self.work_dir, 'antlr')
         makedirs(antlr_dir, exist_ok=True)
-        # Add the path of the built grammars to the Python path to be available at parsing.
-        if antlr_dir not in sys.path:
-            sys.path.append(antlr_dir)
 
         # Copy the grammars from the package to the given working directory.
         antlr_resources = ['ANTLRv4Lexer.g4', 'ANTLRv4Parser.g4', 'LexBasic.g4', 'LexerAdaptor.py']