Fix "for ... if" bug introduced since 3.6.2...

However we've isolated and documented the 3.x grammar a little bit better

test/simple_source/looping/10_for_if_loopback.py

@@ -11,6 +11,7 @@
 #       101_0	COME_FROM         '50' statement: if name == ...to fictional "end if"
 #         101	JUMP_BACK         '16' jump as before to loop head
 
+# RUNNABLE!
 def _slotnames(cls):
     names = []
     for c in cls.__mro__:
@@ -21,3 +22,18 @@ def _slotnames(cls):
                     continue
                 else:
                     names.append(name) # 3.2 bug here jumping to outer for
+
+# From 3.2.6 pdb.py
+# There is no "come_from" after the "if" since the
+# if jumps back to the loop. For this we use
+# grammar rule "ifstmtl"
+def lasti2lineno(linestarts, a):
+    for i in linestarts:
+        if a:
+            return a
+    return -1
+
+assert lasti2lineno([], True) == -1
+assert lasti2lineno([], False) == -1
+assert lasti2lineno([1], False) == -1
+assert lasti2lineno([1], True) == 1

uncompyle6/parsers/parse3.py

@@ -141,18 +141,20 @@ class Python3Parser(PythonParser):
         assert_expr_or ::= assert_expr jmp_true expr
         assert_expr_and ::= assert_expr jmp_false expr
 
-        ifstmt ::= testexpr _ifstmts_jump
+        ifstmt  ::= testexpr _ifstmts_jump
 
         testexpr ::= testfalse
         testexpr ::= testtrue
         testfalse ::= expr jmp_false
         testtrue ::= expr jmp_true
 
-        _ifstmts_jump ::= return_if_stmts
-        _ifstmts_jump ::= c_stmts_opt come_froms
+        _ifstmts_jump  ::= return_if_stmts
+        _ifstmts_jump  ::= c_stmts_opt come_froms
+        _ifstmts_jumpl ::= return_if_stmts
 
         iflaststmt  ::= testexpr c_stmts_opt JUMP_ABSOLUTE
         iflaststmtl ::= testexpr c_stmts_opt JUMP_BACK
+        iflaststmtl ::= testexpr _ifstmts_jumpl
 
         # These are used to keep parse tree indices the same
         jump_forward_else  ::= JUMP_FORWARD ELSE
@@ -330,6 +332,10 @@ class Python3Parser(PythonParser):
     def p_stmt3(self, args):
         """
         stmt               ::= if_expr_lambda
+
+        # If statement inside a loop:
+        lastl_stmt         ::= ifstmtl
+
         stmt               ::= conditional_not_lambda
         if_expr_lambda     ::= expr jmp_false expr return_if_lambda
                                return_stmt_lambda LAMBDA_MARKER

uncompyle6/parsers/parse37.py

@@ -952,6 +952,8 @@ class Python37Parser(Python37BaseParser):
         """
         stmt               ::= if_expr_lambda
         stmt               ::= conditional_not_lambda
+
+        # If statement inside a loop:
         stmt               ::= ifstmtl
 
         if_expr_lambda     ::= expr jmp_false expr return_if_lambda

uncompyle6/semantics/consts.py

@@ -371,14 +371,13 @@ TABLE_DIRECT = {
 #    'return':	        ( '%|return %c\n', 0),
     'return_if_stmt':	( 'return %c\n', 0),
 
-    'ifstmt':		( '%|if %c:\n%+%c%-',
+    "ifstmt":		( "%|if %c:\n%+%c%-",
                             0, # "testexpr" or "testexpr_then"
                             1, # "_ifstmts_jump" or "return_stmts"
                         ),
-
-    'iflaststmt':	( '%|if %c:\n%+%c%-', 0, 1 ),
-    'iflaststmtl':		( '%|if %c:\n%+%c%-', 0, 1 ),
-    'testtrue':         ( 'not %p',
+    'iflaststmt':	( "%|if %c:\n%+%c%-", 0, 1 ),
+    'iflaststmtl':	( "%|if %c:\n%+%c%-", 0, 1 ),
+    'testtrue':         ( "not %p",
                           (0, PRECEDENCE['unary_not']) ),
 
     # Generally the args here are 0: (some sort of) "testexpr",