1 files changed, 74 insertions, 0 deletions
diff --git a/pycparser/ply/ygen.py b/pycparser/ply/ygen.py
new file mode 100644
index 0000000..acf5ca1
--- /dev/null
+++ b/pycparser/ply/ygen.py
@@ -0,0 +1,74 @@
+# ply: ygen.py
+#
+# This is a support program that auto-generates different versions of the YACC parsing
+# function with different features removed for the purposes of performance.
+#
+# Users should edit the method LParser.parsedebug() in yacc.py.   The source code 
+# for that method is then used to create the other methods.   See the comments in
+# yacc.py for further details.
+
+import os.path
+import shutil
+
+def get_source_range(lines, tag):
+    srclines = enumerate(lines)
+    start_tag = '#--! %s-start' % tag
+    end_tag = '#--! %s-end' % tag
+
+    for start_index, line in srclines:
+        if line.strip().startswith(start_tag):
+            break
+
+    for end_index, line in srclines:
+        if line.strip().endswith(end_tag):
+            break
+
+    return (start_index + 1, end_index)
+
+def filter_section(lines, tag):
+    filtered_lines = []
+    include = True
+    tag_text = '#--! %s' % tag
+    for line in lines:
+        if line.strip().startswith(tag_text):
+            include = not include
+        elif include:
+            filtered_lines.append(line)
+    return filtered_lines
+
+def main():
+    dirname = os.path.dirname(__file__)
+    shutil.copy2(os.path.join(dirname, 'yacc.py'), os.path.join(dirname, 'yacc.py.bak'))
+    with open(os.path.join(dirname, 'yacc.py'), 'r') as f:
+        lines = f.readlines()
+
+    parse_start, parse_end = get_source_range(lines, 'parsedebug')
+    parseopt_start, parseopt_end = get_source_range(lines, 'parseopt')
+    parseopt_notrack_start, parseopt_notrack_end = get_source_range(lines, 'parseopt-notrack')
+
+    # Get the original source
+    orig_lines = lines[parse_start:parse_end]
+
+    # Filter the DEBUG sections out
+    parseopt_lines = filter_section(orig_lines, 'DEBUG')
+
+    # Filter the TRACKING sections out
+    parseopt_notrack_lines = filter_section(parseopt_lines, 'TRACKING')
+
+    # Replace the parser source sections with updated versions
+    lines[parseopt_notrack_start:parseopt_notrack_end] = parseopt_notrack_lines
+    lines[parseopt_start:parseopt_end] = parseopt_lines
+
+    lines = [line.rstrip()+'\n' for line in lines]
+    with open(os.path.join(dirname, 'yacc.py'), 'w') as f:
+        f.writelines(lines)
+
+    print('Updated yacc.py')
+
+if __name__ == '__main__':
+    main()
+
+
+
+
+