add a directive to disable SwitchTransform

SwitchTransform is unable to detect all cases of duplicate values, which
result in errors at compile time in the generated code.

Cython/Compiler/Optimize.py

@@ -802,7 +802,7 @@ class IterationTransform(Visitor.EnvTransform):
             ])
 
 
-class SwitchTransform(Visitor.VisitorTransform):
+class SwitchTransform(Visitor.CythonTransform):
     """
     This transformation tries to turn long if statements into C switch statements.
     The requirement is that every clause be an (or of) var == value, where the var
@@ -917,6 +917,10 @@ class SwitchTransform(Visitor.VisitorTransform):
         return False
 
     def visit_IfStatNode(self, node):
+        if not self.current_directives.get('optimize.switchcase_transform'):
+            self.visitchildren(node)
+            return node
+
         common_var = None
         cases = []
         for if_clause in node.if_clauses:
@@ -946,6 +950,10 @@ class SwitchTransform(Visitor.VisitorTransform):
         return switch_node
 
     def visit_CondExprNode(self, node):
+        if not self.current_directives.get('optimize.switchcase_transform'):
+            self.visitchildren(node)
+            return node
+
         not_in, common_var, conditions = self.extract_common_conditions(
             None, node.test, True)
         if common_var is None \
@@ -958,6 +966,10 @@ class SwitchTransform(Visitor.VisitorTransform):
             node.true_val, node.false_val)
 
     def visit_BoolBinopNode(self, node):
+        if not self.current_directives.get('optimize.switchcase_transform'):
+            self.visitchildren(node)
+            return node
+
         not_in, common_var, conditions = self.extract_common_conditions(
             None, node, True)
         if common_var is None \
@@ -972,6 +984,10 @@ class SwitchTransform(Visitor.VisitorTransform):
             ExprNodes.BoolNode(node.pos, value=False, constant_result=False))
 
     def visit_PrimaryCmpNode(self, node):
+        if not self.current_directives.get('optimize.switchcase_transform'):
+            self.visitchildren(node)
+            return node
+
         not_in, common_var, conditions = self.extract_common_conditions(
             None, node, True)
         if common_var is None \
@@ -1015,6 +1031,10 @@ class SwitchTransform(Visitor.VisitorTransform):
         return replacement
 
     def visit_EvalWithTempExprNode(self, node):
+        if not self.current_directives.get('optimize.switchcase_transform'):
+            self.visitchildren(node)
+            return node
+
         # drop unused expression temp from FlattenInListTransform
         orig_expr = node.subexpression
         temp_ref = node.lazy_temp

Cython/Compiler/Options.py

@@ -129,6 +129,7 @@ directive_defaults = {
 
 # optimizations
     'optimize.inline_defnode_calls': True,
+    'optimize.switchcase_transform': True,
 
 # remove unreachable code
     'remove_unreachable': True,

Cython/Compiler/Pipeline.py

@@ -202,7 +202,7 @@ def create_pipeline(context, mode, exclude_classes=()):
         CalculateQualifiedNamesTransform(context),
         ConsolidateOverflowCheck(context),
         IterationTransform(context),
-        SwitchTransform(),
+        SwitchTransform(context),
         DropRefcountingTransform(),
         FinalOptimizePhase(context),
         GilCheck(),

runtests.py

@@ -399,6 +399,7 @@ class ErrorWriter(object):
     def _collect(self, collect_errors, collect_warnings):
         s = ''.join(self.output)
         result = []
+        runtime_error = False
         for line in s.split('\n'):
             match = self.match_error(line)
             if match:
@@ -406,8 +407,10 @@ class ErrorWriter(object):
                 if (is_warning and collect_warnings) or \
                         (not is_warning and collect_errors):
                     result.append( (int(line), int(column), message.strip()) )
+            elif 'runtime error' in line:
+                runtime_error = True
         result.sort()
-        return [ "%d:%d: %s" % values for values in result ]
+        return [ "%d:%d: %s" % values for values in result ], runtime_error
 
     def geterrors(self):
         return self._collect(True, False)
@@ -701,7 +704,7 @@ class CythonCompileTestCase(unittest.TestCase):
             geterrors = out.geterrors
         except AttributeError:
             out.close()
-            return []
+            return [], False
         else:
             return geterrors()
 
@@ -822,7 +825,7 @@ class CythonCompileTestCase(unittest.TestCase):
                 expect_errors, annotate):
         expected_errors = errors = ()
         if expect_errors:
-            expected_errors = self.split_source_and_output(
+            expected_errors, runtime_error = self.split_source_and_output(
                 test_directory, module, workdir)
             test_directory = workdir
 
@@ -831,7 +834,6 @@ class CythonCompileTestCase(unittest.TestCase):
             try:
                 sys.stderr = ErrorWriter()
                 self.run_cython(test_directory, module, workdir, incdir, annotate)
-                errors = sys.stderr.geterrors()
             finally:
                 sys.stderr = old_stderr
 
@@ -857,7 +859,13 @@ class CythonCompileTestCase(unittest.TestCase):
         if self.cython_only:
             so_path = None
         else:
-            so_path = self.run_distutils(test_directory, module, workdir, incdir)
+            try:
+                so_path = self.run_distutils(test_directory, module, workdir, incdir)
+            except:
+                if runtime_error:
+                    return None
+                else:
+                    raise
         return so_path
 
 class CythonRunTestCase(CythonCompileTestCase):
@@ -882,7 +890,7 @@ class CythonRunTestCase(CythonCompileTestCase):
                 self.success = False
                 ext_so_path = self.runCompileTest()
                 failures, errors = len(result.failures), len(result.errors)
-                if not self.cython_only:
+                if not self.cython_only and ext_so_path is not None:
                     self.run_tests(result, ext_so_path)
                 if failures == len(result.failures) and errors == len(result.errors):
                     # No new errors...

tests/errors/e_switch_transform.pyx

+# cython: optimize.switchcase_transform=True
+# mode: error
+
+import cython
+
+cdef extern from "includes/e_switch_transform_support.h":
+    enum:
+        ONE
+        ONE_AGAIN
+
+def is_not_one(int i):
+    return i != ONE and i != ONE_AGAIN
+
+_ERRORS = u'''
+runtime error
+'''

tests/errors/includes/e_switch_transform_support.h

+#ifndef E_SWITCH_TRANSFORM_SUPPORT_H_
+#define E_SWITCH_TRANSFORM_SUPPORT_H_ 1
+
+enum {
+    ONE=1,
+    ONE_AGAIN=1
+};
+
+#endif /* E_SWITCH_TRANSFORM_SUPPORT_H_ */

tests/run/includes/switch_transform_support.h

+#ifndef SWITCH_TRANSFORM_SUPPORT_H_
+#define SWITCH_TRANSFORM_SUPPORT_H_ 1
+
+enum {
+    ONE=1,
+    ONE_AGAIN=1
+};
+
+#endif /* SWITCH_TRANSFORM_SUPPORT_H_ */

tests/run/switch_transform.pyx

+# cython: optimize.switchcase_transform=False
+
+cdef extern from "includes/switch_transform_support.h":
+    enum:
+        ONE
+        ONE_AGAIN
+
+def is_not_one(int i):
+    """
+    >>> is_not_one(1)
+    False
+    >>> is_not_one(2)
+    True
+    """
+    return i != ONE and i != ONE_AGAIN