Updates based on implementation progress

pep-0432.txt

@@ -177,6 +177,8 @@ be able to control the following aspects of the final interpreter state:
 
 * Whether or not to use randomised hashes (and if used, potentially specify
   a specific random seed)
+* Whether or not to enable the import system (required by CPython's
+  build process when freezing the importlib._bootstrap bytecode)
 * The "Where is Python located?" elements in the ``sys`` module:
   * ``sys.executable``
   * ``sys.base_exec_prefix``
@@ -406,6 +408,7 @@ Other configuration settings
 
 TBD: Cover the initialization of the following in more detail:
 
+* Completely disabling the import system
 * The initial warning system state:
   * ``sys.warnoptions``
   * (-W option, PYTHONWARNINGS)
@@ -612,9 +615,10 @@ configuration::
         int ignore_environment;   /* -E switch */
         int use_hash_seed;        /* PYTHONHASHSEED */
         unsigned long hash_seed;  /* PYTHONHASHSEED */
+        int _disable_importlib;   /* Needed by freeze_importlib */
     } Py_CoreConfig;
 
-    #define Py_CoreConfig_INIT {0, -1, 0}
+    #define Py_CoreConfig_INIT {0, -1, 0, 0}
 
 The core configuration settings pointer may be ``NULL``, in which case the
 default values are ``ignore_environment = 0`` and ``use_hash_seed = -1``.
@@ -661,6 +665,13 @@ the empty string or the value ``"random"``, both ``use_hash_seed`` and
 ``hash_seed``. On success the function will return zero. A non-zero return
 value indicates an error (most likely in the conversion to an integer).
 
+The ``_disable_importlib`` setting is used as part of the CPython build
+process to create an interpreter with no import capability at all. It is
+considered private to the CPython development team (hence the leading
+underscore), as the only known use case is to permit compiler changes
+that invalidate the previously frozen bytecode for ``importlib._bootstrap``
+without breaking the build process.
+
 The aim is to keep this initial level of configuration as small as possible
 in order to keep the bootstrapping environment consistent across
 different embedding applications. If we can create a valid interpreter state
@@ -1046,8 +1057,17 @@ Open Questions
 Implementation
 ==============
 
-None as yet. Once I have a reasonably solid plan of attack, I intend to work
-on a reference implementation as a feature branch in my BitBucket sandbox [2_]
+The reference implementation is being developed as a feature branch in my
+BitBucket sandbox [2_].
+
+As the number of application binaries created by the build process is now
+four, the reference implementation also creates a new top level "Apps"
+directory in the CPython source tree. The source files for the main
+``python`` binary and the new ``pysystem`` binary will be located in that
+directory. The source files for the ``_freeze_importlib`` binary and the
+``_testembed`` binary have been moved out of the Modules directory (which
+is intended for CPython builtin and extension modules) and into the Tools
+directory.
 
 
 References
@@ -1057,7 +1077,7 @@ References
    (http://wiki.python.org/moin/CPythonInterpreterInitialization)
 
 .. [2] BitBucket Sandbox
-   (https://bitbucket.org/ncoghlan/cpython_sandbox)
+   (https://bitbucket.org/ncoghlan/cpython_sandbox/compare/pep432_modular_bootstrap..default#commits)
 
 .. [3] \*nix getpath implementation
    (http://hg.python.org/cpython/file/default/Modules/getpath.c)