Added ability to round-trip test cases

t11230 · t11230 · commit 780fec8a2e32 · 2020-08-09T09:17:29.000-04:00
- Switched test_designated_initializers to use the new code
diff --git a/test/test_pycparserext.py b/test/test_pycparserext.py
@@ -2,6 +2,53 @@
 import pytest
 
 
+# Inspired from pycparser's compare_asts test function
+def _compare_asts(first, second):
+    if type(first) is not type(second):
+        return False
+
+    if isinstance(first, tuple):
+        if first[0] != second[0]:
+            return False
+
+        return _compare_asts(first[1], second[1])
+
+    for attr in first.attr_names:
+        if getattr(first, attr) != getattr(second, attr):
+            return False
+
+    for i, c1 in enumerate(first.children()):
+        if not _compare_asts(c1, second.children()[i]):
+            return False
+    return True
+
+
+def _round_trip_matches(src):
+    from pycparserext.ext_c_parser import GnuCParser
+    from pycparserext.ext_c_generator import GnuCGenerator
+
+    p = GnuCParser()
+
+    first_ast = p.parse(src)
+
+    gen = GnuCGenerator().visit(first_ast)
+
+    second_ast = p.parse(gen)
+
+    if not _compare_asts(first_ast, second_ast):
+        print('First AST:')
+        first_ast.show()
+
+        print('Generated code:')
+        print(gen)
+
+        print('Second AST:')
+        second_ast.show()
+
+        return False
+    return True
+
+
 def test_asm_volatile_1():
     src = """
     void read_tsc(void) {
@@ -388,14 +435,7 @@ def test_designated_initializers():
 
     char char_map[256] = { [0 ... 255] = '?', ['0' ... '9'] = 'X' };
     """
-    import pycparserext.ext_c_parser as ext_c_parser
-    import pycparserext.ext_c_generator as ext_c_generator
-
-    parser = ext_c_parser.GnuCParser()
-    ast = parser.parse(src)
-    ast.show()
-    gen = ext_c_generator.GnuCGenerator()
-    print(gen.visit(ast))
+    assert _round_trip_matches(src)
 
 
 def test_node_visitor():
