replace the incorrect and leaky global c-tuple type cache by a per-module one

Cython/Compiler/ExprNodes.py

@@ -6529,9 +6529,7 @@ class TupleNode(SequenceNode):
         if any(type.is_pyobject or type.is_unspecified or type.is_fused for type in arg_types):
             return tuple_type
         else:
-            type = PyrexTypes.c_tuple_type(arg_types)
-            env.declare_tuple_type(self.pos, type)
-            return type
+            return env.declare_tuple_type(self.pos, arg_types).type
 
     def analyse_types(self, env, skip_children=False):
         if len(self.args) == 0:
@@ -6542,8 +6540,7 @@ class TupleNode(SequenceNode):
             if not skip_children:
                 self.args = [arg.analyse_types(env) for arg in self.args]
             if not self.mult_factor and not any(arg.type.is_pyobject or arg.type.is_fused for arg in self.args):
-                self.type = PyrexTypes.c_tuple_type(arg.type for arg in self.args)
-                env.declare_tuple_type(self.pos, self.type)
+                self.type = env.declare_tuple_type(self.pos, (arg.type for arg in self.args)).type
                 self.is_temp = 1
                 return self
             else:

Cython/Compiler/Nodes.py

@@ -1180,10 +1180,9 @@ class CTupleBaseTypeNode(CBaseTypeNode):
                 error(c.pos, "Tuple types can't (yet) contain Python objects.")
                 return error_type
             component_types.append(type)
-        type = PyrexTypes.c_tuple_type(component_types)
-        entry = env.declare_tuple_type(self.pos, type)
+        entry = env.declare_tuple_type(self.pos, component_types)
         entry.used = True
-        return type
+        return entry.type
 
 
 class FusedTypeNode(CBaseTypeNode):

Cython/Compiler/PyrexTypes.py

@@ -3684,13 +3684,11 @@ class CTupleType(CType):
         env.use_utility_code(self._convert_from_py_code)
         return True
 
-c_tuple_types = {}
+
 def c_tuple_type(components):
     components = tuple(components)
-    tuple_type = c_tuple_types.get(components)
-    if tuple_type is None:
     cname = Naming.ctuple_type_prefix + type_list_identifier(components)
-        tuple_type = c_tuple_types[components] = CTupleType(cname, components)
+    tuple_type = CTupleType(cname, components)
     return tuple_type
 
 

Cython/Compiler/Symtab.py

@@ -610,8 +610,8 @@ class Scope(object):
         self.sue_entries.append(entry)
         return entry
 
-    def declare_tuple_type(self, pos, type):
-        return self.outer_scope.declare_tuple_type(pos, type)
+    def declare_tuple_type(self, pos, components):
+        return self.outer_scope.declare_tuple_type(pos, components)
 
     def declare_var(self, name, type, pos,
                     cname = None, visibility = 'private',
@@ -1049,6 +1049,7 @@ class ModuleScope(Scope):
         self.cached_builtins = []
         self.undeclared_cached_builtins = []
         self.namespace_cname = self.module_cname
+        self._cached_tuple_types = {}
         for var_name in ['__builtins__', '__name__', '__file__', '__doc__', '__path__']:
             self.declare_var(EncodedString(var_name), py_object_type, None)
 
@@ -1068,18 +1069,24 @@ class ModuleScope(Scope):
 
         return self.outer_scope.lookup(name, language_level=language_level)
 
-    def declare_tuple_type(self, pos, type):
-        cname = type.cname
+    def declare_tuple_type(self, pos, components):
+        components = tuple(components)
+        try:
+            ttype = self._cached_tuple_types[components]
+        except KeyError:
+            ttype = self._cached_tuple_types[components] = PyrexTypes.c_tuple_type(components)
+        cname = ttype.cname
         entry = self.lookup_here(cname)
         if not entry:
             scope = StructOrUnionScope(cname)
-            for ix, component in enumerate(type.components):
+            for ix, component in enumerate(components):
                 scope.declare_var(name="f%s" % ix, type=component, pos=pos)
-            struct_entry = self.declare_struct_or_union(cname + '_struct', 'struct', scope, typedef_flag=True, pos=pos, cname=cname)
+            struct_entry = self.declare_struct_or_union(
+                cname + '_struct', 'struct', scope, typedef_flag=True, pos=pos, cname=cname)
             self.type_entries.remove(struct_entry)
-            type.struct_entry = struct_entry
-            entry = self.declare_type(cname, type, pos, cname)
-        type.entry = entry
+            ttype.struct_entry = struct_entry
+            entry = self.declare_type(cname, ttype, pos, cname)
+        ttype.entry = entry
         return entry
 
     def declare_builtin(self, name, pos):