Apply the switch-transformation also recursively to if-clauses and else-body...

Apply the switch-transformation also recursively to if-clauses and else-body of if-statements that were converted.

CHANGES.rst

@@ -2,6 +2,16 @@
 Cython Changelog
 ================
 
+0.28.2 (2018-??-??)
+===================
+
+Bugs fixed
+----------
+
+* The ``switch`` statement generation failed to apply to the body of converted
+  if-statements
+
+
 0.28.1 (2018-03-18)
 ===================
 

Cython/Compiler/Optimize.py

@@ -1205,6 +1205,11 @@ class SwitchTransform(Visitor.EnvTransform):
             self.visitchildren(node)
             return node
 
+        # Recurse into body subtrees that we left untouched so far.
+        self.visitchildren(node, 'else_clause')
+        for case in cases:
+            self.visitchildren(case, 'body')
+
         common_var = unwrap_node(common_var)
         switch_node = Nodes.SwitchStatNode(pos=node.pos,
                                            test=common_var,

tests/run/switch.pyx

@@ -143,6 +143,75 @@ def switch_c(int x):
     return -1
 
 
+
+@cython.test_assert_path_exists(
+    '//SwitchStatNode',
+    '//SwitchStatNode//SwitchStatNode',
+)
+@cython.test_fail_if_path_exists('//BoolBinopNode', '//PrimaryCmpNode')
+def switch_in_switch(int x, int y):
+    """
+    >>> switch_in_switch(1, 1)
+    (1, 1)
+    >>> switch_in_switch(1, 2)
+    (1, 2)
+    >>> switch_in_switch(1, 4)
+    (1, 3)
+
+    >>> switch_in_switch(2, 1)
+    (2, 1)
+    >>> switch_in_switch(2, 2)
+    (2, 2)
+    >>> switch_in_switch(2, 3)
+    (2, 3)
+    >>> switch_in_switch(2, 4)
+    (2, 4)
+    >>> switch_in_switch(2, 20)
+    (2, 4)
+
+    >>> switch_in_switch(3, 0)
+    False
+    >>> switch_in_switch(3, 1)
+    True
+    >>> switch_in_switch(3, 2)
+    True
+    >>> switch_in_switch(3, 3)
+    True
+    >>> switch_in_switch(3, 4)
+    False
+
+    >>> switch_in_switch(20, 0)
+    True
+    >>> switch_in_switch(20, 1)
+    False
+    >>> switch_in_switch(20, 3)
+    False
+    >>> switch_in_switch(20, 4)
+    True
+    """
+    if x == 1:
+        if y == 1:
+            return 1,1
+        elif y == 2:
+            return 1,2
+        else:
+            return 1,3
+    elif x == 2:
+        if y == 1:
+            return 2,1
+        elif y == 2:
+            return 2,2
+        elif y == 3:
+            return 2,3
+        else:
+            return 2,4
+    elif x == 3:
+        return y in (1,2,3)
+    else:
+        return y not in (1,2,3)
+    return 'FAILED'
+
+
 @cython.test_assert_path_exists('//SwitchStatNode')
 @cython.test_fail_if_path_exists('//IfStatNode')
 def switch_or(int x):