fix #855: make "import *" include all necessary "from_py" coercion helper functions

CHANGES.rst

@@ -8,6 +8,10 @@ Latest changes
 Bugs fixed
 ----------
 
+* Code that uses "from xyz import *" and global C struct/union/array
+  variables could fail to compile due to missing helper functions.
+  This fixes ticket 851.
+
 * Misnamed PEP 492 coroutine property ``cr_yieldfrom`` renamed to
   ``cr_await`` to match CPython.
 

Cython/Compiler/ModuleNode.py

@@ -102,6 +102,13 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         env.directives = self.directives
         self.body.analyse_declarations(env)
 
+    def prepare_utility_code(self):
+        # prepare any utility code that must be created before code generation
+        # specifically: CythonUtilityCode
+        env = self.scope
+        if env.has_import_star:
+            self.create_import_star_conversion_utility_code(env)
+
     def process_implementation(self, options, result):
         env = self.scope
         env.return_type = PyrexTypes.c_void_type
@@ -1964,6 +1971,14 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
             code.putln(
                 "};")
 
+    def create_import_star_conversion_utility_code(self, env):
+        # Create all conversion helpers that are needed for "import *" assignments.
+        # Must be done before code generation to support CythonUtilityCode.
+        for name, entry in env.entries.items():
+            if entry.is_cglobal and entry.used:
+                if not entry.type.is_pyobject:
+                    entry.type.create_from_py_utility_code(env)
+
     def generate_import_star(self, env, code):
         env.use_utility_code(UtilityCode.load_cached("CStringEquals", "StringTools.c"))
         code.putln()
@@ -2001,7 +2016,8 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
                     code.putln("%s = %s;" % (
                         entry.cname,
                         PyrexTypes.typecast(entry.type, py_object_type, "o")))
-                elif entry.type.from_py_function:
+                elif entry.type.create_from_py_utility_code(env):
+                    # if available, utility code was already created in self.prepare_utility_code()
                     rhs = "%s(o)" % entry.type.from_py_function
                     if entry.type.is_enum:
                         rhs = PyrexTypes.typecast(entry.type, PyrexTypes.c_long_type, rhs)

Cython/Compiler/Pipeline.py

@@ -80,6 +80,7 @@ def use_utility_code_definitions(scope, target, seen=None):
 
 def inject_utility_code_stage_factory(context):
     def inject_utility_code_stage(module_node):
+        module_node.prepare_utility_code()
         use_utility_code_definitions(context.cython_scope, module_node.scope)
         added = []
         # Note: the list might be extended inside the loop (if some utility code

tests/run/import_star.pyx

+# mode: run
 
 cdef object executable, version_info
 cdef long hexversion
 
+ctypedef struct MyStruct:
+    int x, y, z
+
+# conversion code for this struct will be generated but not used
+# (there used to be a problem getting Cython conversion code generated here)
+cdef MyStruct _no_such_name_ = MyStruct(1, 2, 3)
+
+
 from sys import *
 
+
 def test_cdefed_objects():
     """
     >>> ex, vi = test_cdefed_objects()
@@ -12,6 +22,7 @@ def test_cdefed_objects():
     """
     return executable, version_info
 
+
 def test_cdefed_cvalues():
     """
     >>> hexver = test_cdefed_cvalues()
@@ -20,6 +31,7 @@ def test_cdefed_cvalues():
     """
     return hexversion
 
+
 def test_non_cdefed_names():
     """
     >>> mod, pth = test_non_cdefed_names()