Apr 29, 2025 · Apr 28, 2025
diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
 * Remove the private ``_Py_InitializeMain()`` function. It was a
  :term:`provisional API` added to Python 3.8 by :pep:`587`.
  (Contributed by Victor Stinner in :gh:`129033`.)

 * The undocumented APIs :c:macro:`!Py_C_RECURSION_LIMIT` and
  :c:member:`!PyThreadState.c_recursion_remaining`, added in 3.13, are removed
  without a deprecation period.
  Please use :c:func:`Py_EnterRecursiveCall` to guard against runaway recursion
  in C code.
  (Removed in :gh:`133079`, see also :gh:`130396`.)
diff --git a/Include/cpython/pystate.h b/Include/cpython/pystate.h

    int py_recursion_remaining;
    int py_recursion_limit;

    int c_recursion_remaining; /* Retained for backwards compatibility. Do not use */
    int recursion_headroom; /* Allow 50 more calls to handle any errors. */

    /* 'tracing' keeps track of the execution depth when tracing/profiling.
    _PyRemoteDebuggerSupport remote_debugger_support;
 };

 # define Py_C_RECURSION_LIMIT 5000

 /* other API */

 /* Similar to PyThreadState_Get(), but don't issue a fatal error
diff --git a/Misc/NEWS.d/next/C_API/2025-04-28-13-27-48.gh-issue-133079.DJL2sK.rst b/Misc/NEWS.d/next/C_API/2025-04-28-13-27-48.gh-issue-133079.DJL2sK.rst
 The undocumented APIs :c:macro:`!Py_C_RECURSION_LIMIT` and
 :c:member:`!PyThreadState.c_recursion_remaining`, added in 3.13, are removed
 without a deprecation period.
diff --git a/Python/pystate.c b/Python/pystate.c

    tstate->py_recursion_limit = interp->ceval.recursion_limit;
    tstate->py_recursion_remaining = interp->ceval.recursion_limit;
    tstate->c_recursion_remaining = 2;
    tstate->exc_info = &tstate->exc_state;

    // PyGILState_Release must not try to delete this thread state.
diff --git a/Python/vm-state.md b/Python/vm-state.md

 Another important piece of VM state is the **thread state**, held in `tstate`.
 The current frame pointer, `frame`, is always equal to `tstate->current_frame`.
 The thread state also holds the exception state (`tstate->exc_info`) and the recursion counters (`tstate->c_recursion_remaining` and `tstate->py_recursion_remaining`).
 The thread state also holds the exception state (`tstate->exc_info`) and
 recursion tracking data (`tstate->py_recursion_remaining`, `tstate->c_stack*`).

 The thread state is also used to access the **interpreter state** (`tstate->interp`), which is important since the "eval breaker" flags are stored there (`tstate->interp->ceval.eval_breaker`, an "atomic" variable), as well as the "PEP 523 function" (`tstate->interp->eval_frame`).
 The interpreter state also holds the optimizer state (`optimizer` and some counters).
Original file line number	Diff line number	Diff line change
Expand Up		@@ -2256,3 +2256,10 @@ Removed
		* Remove the private ``_Py_InitializeMain()`` function. It was a
		:term:`provisional API` added to Python 3.8 by :pep:`587`.
		(Contributed by Victor Stinner in :gh:`129033`.)

		* The undocumented APIs :c:macro:`!Py_C_RECURSION_LIMIT` and
		:c:member:`!PyThreadState.c_recursion_remaining`, added in 3.13, are removed
		without a deprecation period.
		Please use :c:func:`Py_EnterRecursiveCall` to guard against runaway recursion
		in C code.
		(Removed in :gh:`133079`, see also :gh:`130396`.)
Original file line number	Diff line number	Diff line change
Expand Up		@@ -120,8 +120,6 @@ struct _ts {

		int py_recursion_remaining;
		int py_recursion_limit;

		int c_recursion_remaining; /* Retained for backwards compatibility. Do not use */
		int recursion_headroom; /* Allow 50 more calls to handle any errors. */

		/* 'tracing' keeps track of the execution depth when tracing/profiling.
Expand DownExpand Up		@@ -212,8 +210,6 @@ struct _ts {
		_PyRemoteDebuggerSupport remote_debugger_support;
		};

		# define Py_C_RECURSION_LIMIT 5000

		/* other API */

		/* Similar to PyThreadState_Get(), but don't issue a fatal error
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		The undocumented APIs :c:macro:`!Py_C_RECURSION_LIMIT` and
		:c:member:`!PyThreadState.c_recursion_remaining`, added in 3.13, are removed
		without a deprecation period.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1533,7 +1533,6 @@ init_threadstate(_PyThreadStateImpl *_tstate,

		tstate->py_recursion_limit = interp->ceval.recursion_limit;
		tstate->py_recursion_remaining = interp->ceval.recursion_limit;
		tstate->c_recursion_remaining = 2;
		tstate->exc_info = &tstate->exc_state;

		// PyGILState_Release must not try to delete this thread state.
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -73,7 +73,8 @@ It will be more complex in the JIT.

		Another important piece of VM state is the thread state, held in `tstate`.
		The current frame pointer, `frame`, is always equal to `tstate->current_frame`.
		The thread state also holds the exception state (`tstate->exc_info`) and the recursion counters (`tstate->c_recursion_remaining` and `tstate->py_recursion_remaining`).
		The thread state also holds the exception state (`tstate->exc_info`) and
		recursion tracking data (`tstate->py_recursion_remaining`, `tstate->c_stack*`).

		The thread state is also used to access the interpreter state (`tstate->interp`), which is important since the "eval breaker" flags are stored there (`tstate->interp->ceval.eval_breaker`, an "atomic" variable), as well as the "PEP 523 function" (`tstate->interp->eval_frame`).
		The interpreter state also holds the optimizer state (`optimizer` and some counters).
Expand Down