Add pop return check from decompyle3

uncompyle6/parsers/parse38.py

@@ -1,4 +1,4 @@
-#  Copyright (c) 2017-2020, 2022-2023 Rocky Bernstein
+#  Copyright (c) 2017-2020, 2022-2024 Rocky Bernstein
 #
 #  This program is free software: you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -17,9 +17,12 @@ spark grammar differences over Python 3.7 for Python 3.8
 """
 from __future__ import print_function
 
-from uncompyle6.parser import PythonParserSingle, nop_func
 from spark_parser import DEFAULT_DEBUG as PARSER_DEFAULT_DEBUG
+
+from uncompyle6.parser import PythonParserSingle, nop_func
 from uncompyle6.parsers.parse37 import Python37Parser
+from uncompyle6.parsers.reducecheck.pop_return import pop_return_check
+
 
 class Python38Parser(Python37Parser):
     def p_38_stmt(self, args):
@@ -362,13 +365,24 @@ class Python38Parser(Python37Parser):
         """
         )
 
-    def customize_grammar_rules(self, tokens, customize):
-        super(Python37Parser, self).customize_grammar_rules(tokens, customize)
+    def customize_reduce_checks_full38(self, tokens, customize):
+        """
+        Extra tests when a reduction is made in the full grammar.
+
+        Reductions here are extended from those used in the lambda grammar
+        """
         self.remove_rules_38()
+        self.check_reduce["pop_return"] = "tokens"
         self.check_reduce["whileTruestmt38"] = "tokens"
         self.check_reduce["whilestmt38"] = "tokens"
         self.check_reduce["try_elsestmtl38"] = "AST"
 
+        self.reduce_check_table["pop_return"] = pop_return_check
+
+    def customize_grammar_rules(self, tokens, customize):
+        super(Python37Parser, self).customize_grammar_rules(tokens, customize)
+        self.customize_reduce_checks_full38(tokens, customize)
+
         # For a rough break out on the first word. This may
         # include instructions that don't need customization,
         # but we'll do a finer check after the rough breakout.
@@ -423,11 +437,7 @@ class Python38Parser(Python37Parser):
         # Determine if we have an iteration CALL_FUNCTION_1.
         has_get_iter_call_function1 = False
         for i, token in enumerate(tokens):
-            if (
-                token == "GET_ITER"
-                and i < n - 2
-                and tokens[i + 1] == "CALL_FUNCTION_1"
-            ):
+            if token == "GET_ITER" and i < n - 2 and tokens[i + 1] == "CALL_FUNCTION_1":
                 has_get_iter_call_function1 = True
 
         for i, token in enumerate(tokens):
@@ -577,14 +587,10 @@ class Python38Parser(Python37Parser):
                        """
                     self.addRule(rule, nop_func)
 
-
-
-
-
     def reduce_is_invalid(self, rule, ast, tokens, first, last):
-        invalid = super(Python38Parser,
-                        self).reduce_is_invalid(rule, ast,
-                                                tokens, first, last)
+        invalid = super(Python38Parser, self).reduce_is_invalid(
+            rule, ast, tokens, first, last
+        )
         self.remove_rules_38()
         if invalid:
             return invalid
@@ -612,7 +618,7 @@ if __name__ == "__main__":
     p = Python38Parser()
     p.remove_rules_38()
     p.check_grammar()
-    from xdis.version_info import PYTHON_VERSION_TRIPLE, IS_PYPY
+    from xdis.version_info import IS_PYPY, PYTHON_VERSION_TRIPLE
 
     if PYTHON_VERSION_TRIPLE[:2] == (3, 8):
         lhs, rhs, tokens, right_recursive, dup_rhs = p.check_sets()
@@ -635,7 +641,9 @@ if __name__ == "__main__":
         remain_tokens = set(remain_tokens) - opcode_set
         print(remain_tokens)
         import sys
+
         if len(sys.argv) > 1:
             from spark_parser.spark import rule2str
+
             for rule in sorted(p.rule2name.items()):
                 print(rule2str(rule[0]))

uncompyle6/parsers/reducecheck/pop_return.py

@@ -0,0 +1,10 @@
+#  Copyright (c) 2020 Rocky Bernstein
+
+
+def pop_return_check(
+    self, lhs: str, n: int, rule, ast, tokens: list, first: int, last: int
+) -> bool:
+    # If the first instruction of return_expr (the instruction after POP_TOP) is
+    # has a linestart, then the POP_TOP was probably part of the previous
+    # statement, such as a call() where the return value is discarded.
+    return tokens[first + 1].linestart