Ensure utility code keeps the directives that it was compiled with (GH-3615)

When it's merged into the main module, wrap it in a CompilerDirectivesNode.

Cython/Compiler/ModuleNode.py

@@ -87,7 +87,6 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
     child_attrs = ["body"]
     directives = None
 
-
     def merge_in(self, tree, scope, merge_scope=False):
         # Merges in the contents of another tree, and possibly scope. With the
         # current implementation below, this must be done right prior
@@ -123,6 +122,13 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
 
             self.scope.merge_in(scope)
 
+    def with_compiler_directives(self):
+        # When merging a utility code module into the user code we need to preserve
+        # the original compiler directives. This returns the body of the module node,
+        # wrapped in its set of directives.
+        body = Nodes.CompilerDirectivesNode(self.pos, directives=self.directives, body=self.body)
+        return body
+
     def analyse_declarations(self, env):
         if has_np_pythran(env):
             Pythran.include_pythran_generic(env)

Cython/Compiler/Pipeline.py

@@ -128,7 +128,8 @@ def inject_utility_code_stage_factory(context):
                         module_node.scope.utility_code_list.append(dep)
             tree = utilcode.get_tree(cython_scope=context.cython_scope)
             if tree:
-                module_node.merge_in(tree.body, tree.scope, merge_scope=True)
+                module_node.merge_in(tree.with_compiler_directives(),
+                                     tree.scope, merge_scope=True)
         return module_node
     return inject_utility_code_stage
 

tests/memoryview/memoryview_no_binding_T3613.pyx

+# mode: compile
+# tag: memoryview
+
+# cython: binding=False
+
+# See GH 3613 - when memoryviews were compiled with binding off they ended up in an
+# inconsistent state where different directives were applied at different stages
+# of the pipeline
+
+import cython
+
+def f(double[:] a):
+    pass
+
+@cython.binding(False)
+def g(double[:] a):
+    pass
+
+@cython.binding(True)
+def h(double[:] a):
+    pass