/// <summary>
/// Given a qualified name of the form A.B.C.D, attempt to load
/// an assembly named after each of A.B.C.D, A.B.C, A.B, A. This
/// will only actually probe for the assembly once for each unique
/// namespace. Returns true if any assemblies were loaded.
/// </summary>
/// <remarks>
/// TODO item 3 "* Deprecate implicit loading of assemblies":
/// Set the fromFile flag if the name of the loaded assembly matches
/// the fully qualified name that was requested if the framework
/// actually loads an assembly.
/// Call ONLY for namespaces that HAVE NOT been cached yet.
/// </remarks>
public static bool LoadImplicit(string name, bool warn = true)
{
string[] names = name.Split('.');
var loaded = false;
var s = "";
Assembly lastAssembly = null;
HashSet <Assembly> assembliesSet = null;
for (var i = 0; i < names.Length; i++)
{
s = i == 0 ? names[0] : s + "." + names[i];
if (!probed.ContainsKey(s))
{
if (assembliesSet == null)
{
assembliesSet = new HashSet <Assembly>(AppDomain.CurrentDomain.GetAssemblies());
}
Assembly a = FindLoadedAssembly(s);
if (a == null)
{
a = LoadAssemblyPath(s);
}
if (a == null)
{
a = LoadAssembly(s);
}
if (a != null && !assembliesSet.Contains(a))
{
loaded = true;
lastAssembly = a;
}
probed[s] = 1;
}
}
// Deprecation warning
if (warn && loaded)
{
string location = Path.GetFileNameWithoutExtension(lastAssembly.Location);
string deprWarning = "The module was found, but not in a referenced namespace.\n" +
$"Implicit loading is deprecated. Please use clr.AddReference('{location}').";
Exceptions.deprecation(deprWarning);
}
return(loaded);
}
/// <summary>
/// The actual import hook that ties Python to the managed world.
/// </summary>
public static IntPtr __import__(IntPtr self, IntPtr args, IntPtr kw)
{
// Replacement for the builtin __import__. The original import
// hook is saved as this.py_import. This version handles CLR
// import and defers to the normal builtin for everything else.
var num_args = Runtime.PyTuple_Size(args);
if (num_args < 1)
{
return(Exceptions.RaiseTypeError("__import__() takes at least 1 argument (0 given)"));
}
// borrowed reference
IntPtr py_mod_name = Runtime.PyTuple_GetItem(args, 0);
if (py_mod_name == IntPtr.Zero ||
!Runtime.IsStringType(py_mod_name))
{
return(Exceptions.RaiseTypeError("string expected"));
}
// Check whether the import is of the form 'from x import y'.
// This determines whether we return the head or tail module.
IntPtr fromList = IntPtr.Zero;
var fromlist = false;
if (num_args >= 4)
{
fromList = Runtime.PyTuple_GetItem(args, 3);
if (fromList != IntPtr.Zero &&
Runtime.PyObject_IsTrue(fromList) == 1)
{
fromlist = true;
}
}
string mod_name = Runtime.GetManagedString(py_mod_name);
// Check these BEFORE the built-in import runs; may as well
// do the Incref()ed return here, since we've already found
// the module.
if (mod_name == "clr")
{
IntPtr clr_module = GetCLRModule(fromList);
if (clr_module != IntPtr.Zero)
{
IntPtr sys_modules = Runtime.PyImport_GetModuleDict();
if (sys_modules != IntPtr.Zero)
{
Runtime.PyDict_SetItemString(sys_modules, "clr", clr_module);
}
}
return(clr_module);
}
if (mod_name == "CLR")
{
Exceptions.deprecation("The CLR module is deprecated. Please use 'clr'.");
IntPtr clr_module = GetCLRModule(fromList);
if (clr_module != IntPtr.Zero)
{
IntPtr sys_modules = Runtime.PyImport_GetModuleDict();
if (sys_modules != IntPtr.Zero)
{
Runtime.PyDict_SetItemString(sys_modules, "clr", clr_module);
}
}
return(clr_module);
}
string realname = mod_name;
string clr_prefix = null;
if (mod_name.StartsWith("CLR."))
{
clr_prefix = "CLR."; // prepend when adding the module to sys.modules
realname = mod_name.Substring(4);
string msg = $"Importing from the CLR.* namespace is deprecated. Please import '{realname}' directly.";
Exceptions.deprecation(msg);
}
else
{
// 2010-08-15: Always seemed smart to let python try first...
// This shaves off a few tenths of a second on test_module.py
// and works around a quirk where 'sys' is found by the
// LoadImplicit() deprecation logic.
// Turns out that the AssemblyManager.ResolveHandler() checks to see if any
// Assembly's FullName.ToLower().StartsWith(name.ToLower()), which makes very
// little sense to me.
IntPtr res = Runtime.PyObject_Call(py_import, args, kw);
if (res != IntPtr.Zero)
{
// There was no error.
if (fromlist && IsLoadAll(fromList))
{
var mod = ManagedType.GetManagedObject(res) as ModuleObject;
mod?.LoadNames();
}
return(res);
}
// There was an error
if (!Exceptions.ExceptionMatches(Exceptions.ImportError))
{
// and it was NOT an ImportError; bail out here.
return(IntPtr.Zero);
}
if (mod_name == string.Empty)
{
// Most likely a missing relative import.
// For example site-packages\bs4\builder\__init__.py uses it to check if a package exists:
// from . import _html5lib
// We don't support them anyway
return(IntPtr.Zero);
}
// Otherwise, just clear the it.
Exceptions.Clear();
}
string[] names = realname.Split('.');
// Now we need to decide if the name refers to a CLR module,
// and may have to do an implicit load (for b/w compatibility)
// using the AssemblyManager. The assembly manager tries
// really hard not to use Python objects or APIs, because
// parts of it can run recursively and on strange threads.
//
// It does need an opportunity from time to time to check to
// see if sys.path has changed, in a context that is safe. Here
// we know we have the GIL, so we'll let it update if needed.
AssemblyManager.UpdatePath();
if (!AssemblyManager.IsValidNamespace(realname))
{
if (!AssemblyManager.LoadImplicit(realname))
{
// May be called when a module being imported imports a module.
// In particular, I've seen decimal import copy import org.python.core
return(Runtime.PyObject_Call(py_import, args, kw));
}
}
// See if sys.modules for this interpreter already has the
// requested module. If so, just return the existing module.
IntPtr modules = Runtime.PyImport_GetModuleDict();
IntPtr module = Runtime.PyDict_GetItem(modules, py_mod_name);
if (module != IntPtr.Zero)
{
if (fromlist)
{
if (IsLoadAll(fromList))
{
var mod = ManagedType.GetManagedObject(module) as ModuleObject;
mod?.LoadNames();
}
Runtime.XIncref(module);
return(module);
}
if (clr_prefix != null)
{
return(GetCLRModule(fromList));
}
module = Runtime.PyDict_GetItemString(modules, names[0]);
Runtime.XIncref(module);
return(module);
}
Exceptions.Clear();
// Traverse the qualified module name to get the named module
// and place references in sys.modules as we go. Note that if
// we are running in interactive mode we pre-load the names in
// each module, which is often useful for introspection. If we
// are not interactive, we stick to just-in-time creation of
// objects at lookup time, which is much more efficient.
// NEW: The clr got a new module variable preload. You can
// enable preloading in a non-interactive python processing by
// setting clr.preload = True
ModuleObject head = mod_name == realname ? null : root;
ModuleObject tail = root;
root.InitializePreload();
foreach (string name in names)
{
ManagedType mt = tail.GetAttribute(name, true);
if (!(mt is ModuleObject))
{
Exceptions.SetError(Exceptions.ImportError, $"No module named {name}");
return(IntPtr.Zero);
}
if (head == null)
{
head = (ModuleObject)mt;
}
tail = (ModuleObject)mt;
if (CLRModule.preload)
{
tail.LoadNames();
}
// Add the module to sys.modules
Runtime.PyDict_SetItemString(modules, tail.moduleName, tail.pyHandle);
// If imported from CLR add CLR.<modulename> to sys.modules as well
if (clr_prefix != null)
{
Runtime.PyDict_SetItemString(modules, clr_prefix + tail.moduleName, tail.pyHandle);
}
}
{
var mod = fromlist ? tail : head;
if (fromlist && IsLoadAll(fromList))
{
mod.LoadNames();
}
Runtime.XIncref(mod.pyHandle);
return(mod.pyHandle);
}
}