Python 2.6- try/except control flow detection

uncompyle6/parsers/parse2.py

@@ -181,6 +181,11 @@ class Python2Parser(PythonParser):
         trystmt      ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK
                          try_middle COME_FROM
 
+        try_middle   ::= JUMP_FORWARD COME_FROM except_stmts
+                         END_FINALLY COME_FROM
+        try_middle   ::= jmp_abs COME_FROM except_stmts
+                         END_FINALLY
+
         except_stmts ::= except_stmts except_stmt
         except_stmts ::= except_stmt
 

uncompyle6/parsers/parse26.py

@@ -27,11 +27,7 @@ class Python26Parser(Python2Parser):
                          POP_TOP END_FINALLY come_froms
 
         try_middle   ::= JUMP_FORWARD COME_FROM except_stmts
-                         END_FINALLY come_froms
+                         come_from_pop END_FINALLY COME_FROM
-        try_middle   ::= JUMP_FORWARD COME_FROM except_stmts
-                         come_from_pop END_FINALLY come_froms
-        try_middle   ::= JUMP_FORWARD COME_FROM except_stmts
-                         END_FINALLY come_froms
 
         try_middle   ::= jmp_abs COME_FROM except_stmts
                          POP_TOP END_FINALLY
@@ -39,9 +35,6 @@ class Python26Parser(Python2Parser):
         try_middle   ::= jmp_abs COME_FROM except_stmts
                          come_from_pop END_FINALLY
 
-        try_middle   ::= jmp_abs COME_FROM except_stmts
-                         END_FINALLY
-
         trystmt      ::= SETUP_EXCEPT suite_stmts_opt come_from_pop
                          try_middle
 

uncompyle6/parsers/parse27.py

@@ -27,11 +27,6 @@ class Python27Parser(Python2Parser):
 
     def p_try27(self, args):
         """
-        try_middle   ::= JUMP_FORWARD COME_FROM except_stmts
-                         END_FINALLY COME_FROM
-        try_middle   ::= jmp_abs COME_FROM except_stmts
-                         END_FINALLY
-
         tryelsestmt    ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK
                            try_middle else_suite COME_FROM
 

uncompyle6/scanners/scanner2.py

@@ -44,7 +44,7 @@ class Scanner2(scan.Scanner):
         Pick out tokens from an uncompyle6 code object, and transform them,
         returning a list of uncompyle6 'Token's.
 
-        The tranformations are made to assist the deparsing grammar.
+        The transformations are made to assist the deparsing grammar.
         Specificially:
            -  various types of LOAD_CONST's are categorized in terms of what they load
            -  COME_FROM instructions are added to assist parsing control structures
@@ -56,7 +56,7 @@ class Scanner2(scan.Scanner):
         """
 
         show_asm = self.show_asm if not show_asm else show_asm
-        # show_asm = 'both'
+        # show_asm = 'after'
         if show_asm in ('both', 'before'):
             from xdis.bytecode import Bytecode
             bytecode = Bytecode(co, self.opc)
@@ -846,6 +846,8 @@ class Scanner2(scan.Scanner):
                                 pass
                             pass
 
+
+                # FIXME: All the <2.6 conditions are is horrible. We need a better way.
                 if label is not None and label != -1:
                     # In Python <= 2.6, the POP_TOP in:
                     #   RETURN_VALUE, POP_TOP
@@ -854,8 +856,19 @@ class Scanner2(scan.Scanner):
                     if not (self.version <= 2.6 and
                             self.code[label] == self.opc.POP_TOP and
                             self.code[self.prev[label]] == self.opc.RETURN_VALUE):
-                        targets[label] = targets.get(label, []) + [offset]
+                        # In Python <= 2.6, don't add a COME_FROM, for:
-            elif op == self.opc.END_FINALLY and offset in self.fixed_jumps:
+                        #     JUMP_FORWARD, END_FINALLY
+                        # or:
+                        #     JUMP_FORWARD, POP_TOP, END_FINALLY
+                        if not (self.version <= 2.6 and op == self.opc.JUMP_FORWARD
+                                and ((self.code[offset+3] == self.opc.END_FINALLY)
+                                     or (self.code[offset+3] == self.opc.POP_TOP
+                                         and self.code[offset+4] == self.opc.END_FINALLY))):
+                            targets[label] = targets.get(label, []) + [offset]
+                            pass
+                        pass
+                    pass
+            elif op == self.opc.END_FINALLY and offset in self.fixed_jumps and self.version == 2.7:
                 label = self.fixed_jumps[offset]
                 targets[label] = targets.get(label, []) + [offset]
         return targets

uncompyle6/scanners/scanner26.py

@@ -75,7 +75,7 @@ class Scanner26(scan.Scanner2):
         Pick out tokens from an uncompyle6 code object, and transform them,
         returning a list of uncompyle6 'Token's.
 
-        The tranformations are made to assist the deparsing grammar.
+        The transformations are made to assist the deparsing grammar.
         Specificially:
            -  various types of LOAD_CONST's are categorized in terms of what they load
            -  COME_FROM instructions are added to assist parsing control structures
@@ -87,7 +87,7 @@ class Scanner26(scan.Scanner2):
         """
 
         show_asm = self.show_asm if not show_asm else show_asm
-        # show_asm = 'both'
+        # show_asm = 'after'
         if show_asm in ('both', 'before'):
             from xdis.bytecode import Bytecode
             bytecode = Bytecode(co, self.opc)

uncompyle6/scanners/scanner3.py

@@ -115,7 +115,7 @@ class Scanner3(Scanner):
         Pick out tokens from an uncompyle6 code object, and transform them,
         returning a list of uncompyle6 'Token's.
 
-        The tranformations are made to assist the deparsing grammar.
+        The transformations are made to assist the deparsing grammar.
         Specificially:
            -  various types of LOAD_CONST's are categorized in terms of what they load
            -  COME_FROM instructions are added to assist parsing control structures