Fix e_declarations.pyx, e_nogilfunctype.pyx, e_tempcast.pyx. All tests pass.

Cython/Compiler/ExprNodes.py

@@ -2791,6 +2791,10 @@ class TypecastNode(ExprNode):
     def analyse_types(self, env):
         base_type = self.base_type.analyse(env)
         _, self.type = self.declarator.analyse(base_type, env)
+        if self.type.is_cfunction:
+            error(self.pos,
+                "Cannot cast to a function type")
+            self.type = PyrexTypes.error_type
         self.operand.analyse_types(env)
         to_py = self.type.is_pyobject
         from_py = self.operand.type.is_pyobject

Cython/Compiler/PyrexTypes.py

@@ -699,8 +699,6 @@ class CFuncType(CType):
             return 0
         if not self.same_calling_convention_as(other_type):
             return 0
-        if self.nogil != other_type.nogil:
-            return 0
         return 1
 
     def compatible_signature_with(self, other_type, as_cmethod = 0):

Cython/Compiler/Symtab.py

@@ -374,6 +374,10 @@ class Scope:
     
     def declare_pyfunction(self, name, pos):
         # Add an entry for a Python function.
+        entry = self.lookup_here(name)
+        if entry:
+            # This is legal Python, but for now will produce invalid C.
+            error(pos, "'%s' already declared" % name)
         entry = self.declare_var(name, py_object_type, pos)
         entry.signature = pyfunction_signature
         self.pyfunc_entries.append(entry)
@@ -1340,9 +1344,9 @@ class CClassScope(ClassScope):
                 if defining and entry.func_cname:
                     error(pos, "'%s' already defined" % name)
                 #print "CClassScope.declare_cfunction: checking signature" ###
-                if type.same_c_signature_as(entry.type, as_cmethod = 1):
+                if type.same_c_signature_as(entry.type, as_cmethod = 1) and type.nogil == entry.type.nogil:
                     pass
-                elif type.compatible_signature_with(entry.type, as_cmethod = 1):
+                elif type.compatible_signature_with(entry.type, as_cmethod = 1) and type.nogil == entry.type.nogil:
                     if type.optional_arg_count and not type.original_sig.optional_arg_count:
                         # Need to put a wrapper taking no optional arguments 
                         # into the method table.

tests/errors/e_declarations.pyx

@@ -5,7 +5,8 @@ cdef extern int ff()()
 cdef void f():
 	cdef void *p
 	cdef int (*h)()
-	h = <int ()()>f
+	h = <int ()()>f # this is an error
+	h = <int (*)()>f # this is OK
 _ERRORS = u"""
 /Local/Projects/D/Pyrex/Source/Tests/Errors3/e_declarations.pyx:1:19: Array element cannot be a function
 /Local/Projects/D/Pyrex/Source/Tests/Errors3/e_declarations.pyx:2:18: Function cannot return an array

tests/errors/e_nogilfunctype.pyx

 cdef extern from *:
-	cdef void f() nogil
-	cdef void (*fp)()
+	cdef void f()
+	cdef void (*fp)() nogil
 
 fp = f
 _ERRORS = u"""
-/Local/Projects/D/Pyrex/Source/Tests/Errors3/e_nogilfunctype.pyx:5:6: Cannot assign type 'void (void) nogil' to 'void (*)(void)'
+/Local/Projects/D/Pyrex/Source/Tests/Errors3/e_nogilfunctype.pyx:5:6: Cannot assign type 'void (void)' to 'void (*)(void) nogil'
 """

tests/errors/e_tempcast.pyx

-cdef object foo, blarg
+cdef object blarg
 
 def foo(obj):
 	cdef int *p