The overflow check was relying on undefined behaviour as it was using the result of the multiplication to do the check, and once the overflow has already happened, any operation on the result is undefined behaviour.

Some extra checks that exercise code paths related to this are also added.

d_initial, the first state of a particular DFA in the parser has always been initialized to 0 in the old pgen as well as the new pgen. As this value is not used and the first state of each DFA is assumed to be the first element in the array representing it, remove d_initial from the parser to reduce complexity.

The macros were working only because our usage happened to parse correctly.  Changing that usage (e.g. with pointers) would break the macros.  This fixes that.

This adds a `feature_version` flag to `ast.parse()` (documented) and `compile()` (hidden) that allow tweaking the parser to support older versions of the grammar. In particular if `feature_version` is 5 or 6, the hacks for the `async` and `await` keyword from PEP 492 are reinstated. (For 7 or higher, these are unconditionally treated as keywords, but they are still special tokens rather than `NAME` tokens that the parser driver recognizes.)



https://bugs.python.org/issue35975

Remove 's' mention as there's no argument.

Change PyDTrace_GC_DONE() argument type from int to Py_ssize_t.

bpo-34247, bpo-36142: The PYTHONMALLOC environment variable has the
priority over PYTHONDEV env var and "-X dev" command line option.
For example, PYTHONMALLOC=malloc PYTHONDEVMODE=1 sets the memory
allocators to "malloc" (and not to "debug").

Add an unit test.

* Update pip to 19.0.3
* Update setuptools to 40.8.0

* _PyPreConfig_Read() now sets temporarily LC_CTYPE to the user
  preferred locale, as _PyPreConfig_Write() will do permanentely.
* Fix _PyCoreConfig_Clear(): clear run_xxx attributes
* _Py_SetArgcArgv() doesn't have to be exported
* _PyCoreConfig_SetGlobalConfig() no longer applies preconfig

* _PyPreConfig_Write() now reallocates the pre-configuration with the
  new memory allocator.
* It is no longer needed to force the "default raw memory allocator"
  to clear pre-configuration and core configuration. Simplify the
  code.
* _PyPreConfig_Write() now does nothing if called after
  Py_Initialize(): no longer check if the allocator is the same.
* Remove _PyMem_GetDebugAllocatorsName(): dev mode sets again
  allocator to "debug".

* _PyPreConfig_Write() now sets the memory allocator.
* _PyPreConfig_Write() gets a return type: _PyInitError.
* _Py_InitializeCore() now reads and writes the pre-configuration
  (set the memory allocator, configure the locale) before reading and
  writing the core configuration.

The development mode now uses the effective name of the debug memory
allocator ("pymalloc_debug" or "malloc_debug"). So the name doesn't
change after setting the memory allocator.

NamedStore has been replaced with Store. The difference between
NamedStore and Store is handled when precess the NamedExpr node
one level upper.

Correctly fixes bpo-36197.

* Move 'allocator' and 'dev_mode' fields from _PyCoreConfig
  to _PyPreConfig.
* Fix InitConfigTests of test_embed: dev_mode sets allocator to
  "debug", add a new tests for env vars with dev mode enabled.

Cast function pointers to (void(*)(void)) before casting to (PyCFunction)
to make "warning: cast between incompatible function types" false alarm quiet.

* Move following fields from _PyCoreConfig to _PyPreConfig:

  * coerce_c_locale
  * coerce_c_locale_warn
  * legacy_windows_stdio
  * utf8_mode

* _PyPreConfig_ReadFromArgv() is now responsible to choose the
  filesystem encoding
* _PyPreConfig_Write() now sets the LC_CTYPE locale