bpo-40421: Add pyframe.h header file (GH-19755)

Add a new separated pyframe.h header file of the PyFrame public C
API: it is included by Python.h.

Add PyFrame_GetLineNumber() to the limited C API.

Replace "struct _frame" with "PyFrameObject" in header files.
PyFrameObject is now defined as struct _frame by pyframe.h which is
included early enough in Python.h.

Author: vstinner

Doc/c-api/reflection.rst

@@ -35,6 +35,8 @@ Reflection
 
    Return the line number that *frame* is currently executing.
 
+   *frame* must not be ``NULL``.
+
 
 .. c:function:: const char* PyEval_GetFuncName(PyObject *func)
 

Doc/whatsnew/3.9.rst

@@ -537,6 +537,9 @@ Optimizations
 Build and C API Changes
 =======================
 
+* Add :c:func:`PyFrame_GetLineNumber` to the limited C API.
+  (Contributed by Victor Stinner in :issue:`40421`.)
+
 * New :c:func:`PyThreadState_GetInterpreter` and
   :c:func:`PyInterpreterState_Get` functions to get the interpreter.
   New :c:func:`PyThreadState_GetFrame` function to get the current frame of a

Include/Python.h

@@ -114,6 +114,7 @@
 #include "classobject.h"
 #include "fileobject.h"
 #include "pycapsule.h"
+#include "pyframe.h"
 #include "traceback.h"
 #include "sliceobject.h"
 #include "cellobject.h"

Include/ceval.h

@@ -28,12 +28,10 @@ Py_DEPRECATED(3.9) PyAPI_FUNC(PyObject *) PyEval_CallFunction(
 Py_DEPRECATED(3.9) PyAPI_FUNC(PyObject *) PyEval_CallMethod(
     PyObject *obj, const char *name, const char *format, ...);
 
-struct _frame; /* Avoid including frameobject.h */
-
 PyAPI_FUNC(PyObject *) PyEval_GetBuiltins(void);
 PyAPI_FUNC(PyObject *) PyEval_GetGlobals(void);
 PyAPI_FUNC(PyObject *) PyEval_GetLocals(void);
-PyAPI_FUNC(struct _frame *) PyEval_GetFrame(void);
+PyAPI_FUNC(PyFrameObject *) PyEval_GetFrame(void);
 
 PyAPI_FUNC(int) Py_AddPendingCall(int (*func)(void *), void *arg);
 PyAPI_FUNC(int) Py_MakePendingCalls(void);
@@ -80,8 +78,8 @@ PyAPI_FUNC(void) Py_LeaveRecursiveCall(void);
 PyAPI_FUNC(const char *) PyEval_GetFuncName(PyObject *);
 PyAPI_FUNC(const char *) PyEval_GetFuncDesc(PyObject *);
 
-PyAPI_FUNC(PyObject *) PyEval_EvalFrame(struct _frame *);
-PyAPI_FUNC(PyObject *) PyEval_EvalFrameEx(struct _frame *f, int exc);
+PyAPI_FUNC(PyObject *) PyEval_EvalFrame(PyFrameObject *);
+PyAPI_FUNC(PyObject *) PyEval_EvalFrameEx(PyFrameObject *f, int exc);
 
 /* Interface for threads.
 

Include/cpython/ceval.h

@@ -23,7 +23,7 @@ PyAPI_FUNC(PyObject *) _PyEval_GetBuiltinId(_Py_Identifier *);
    flag was set, else return 0. */
 PyAPI_FUNC(int) PyEval_MergeCompilerFlags(PyCompilerFlags *cf);
 
-PyAPI_FUNC(PyObject *) _PyEval_EvalFrameDefault(PyThreadState *tstate, struct _frame *f, int exc);
+PyAPI_FUNC(PyObject *) _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int exc);
 
 PyAPI_FUNC(void) _PyEval_SetSwitchInterval(unsigned long microseconds);
 PyAPI_FUNC(unsigned long) _PyEval_GetSwitchInterval(void);

Include/cpython/frameobject.h

@@ -14,7 +14,7 @@ typedef struct {
     int b_level;                /* value stack level to pop to */
 } PyTryBlock;
 
-typedef struct _frame {
+struct _frame {
     PyObject_VAR_HEAD
     struct _frame *f_back;      /* previous frame, or NULL */
     PyCodeObject *f_code;       /* code segment */
@@ -44,7 +44,7 @@ typedef struct _frame {
     char f_executing;           /* whether the frame is still executing */
     PyTryBlock f_blockstack[CO_MAXBLOCKS]; /* for try and loop blocks */
     PyObject *f_localsplus[1];  /* locals+stack, dynamically sized */
-} PyFrameObject;
+};
 
 
 /* Standard object interface */
@@ -79,9 +79,6 @@ PyAPI_FUNC(int) PyFrame_ClearFreeList(void);
 
 PyAPI_FUNC(void) _PyFrame_DebugMallocStats(FILE *out);
 
-/* Return the line of code the frame is currently executing. */
-PyAPI_FUNC(int) PyFrame_GetLineNumber(PyFrameObject *);
-
 #ifdef __cplusplus
 }
 #endif

Include/cpython/pystate.h

@@ -16,7 +16,7 @@ PyAPI_FUNC(PyObject *) _PyInterpreterState_GetMainModule(PyInterpreterState *);
 /* State unique per thread */
 
 /* Py_tracefunc return -1 when raising an exception, or 0 for success. */
-typedef int (*Py_tracefunc)(PyObject *, struct _frame *, int, PyObject *);
+typedef int (*Py_tracefunc)(PyObject *, PyFrameObject *, int, PyObject *);
 
 /* The following values are used for 'what' for tracefunc functions
  *
@@ -56,7 +56,7 @@ struct _ts {
     PyInterpreterState *interp;
 
     /* Borrowed reference to the current frame (it can be NULL) */
-    struct _frame *frame;
+    PyFrameObject *frame;
     int recursion_depth;
     char overflowed; /* The stack has overflowed. Allow 50 more calls
                         to handle the runtime error. */
@@ -184,7 +184,7 @@ PyAPI_FUNC(void) PyThreadState_DeleteCurrent(void);
 
 /* Frame evaluation API */
 
-typedef PyObject* (*_PyFrameEvalFunction)(PyThreadState *tstate, struct _frame *, int);
+typedef PyObject* (*_PyFrameEvalFunction)(PyThreadState *tstate, PyFrameObject *, int);
 
 PyAPI_FUNC(_PyFrameEvalFunction) _PyInterpreterState_GetEvalFrameFunc(
     PyInterpreterState *interp);

Include/cpython/traceback.h

@@ -9,7 +9,7 @@ extern "C" {
 typedef struct _traceback {
     PyObject_HEAD
     struct _traceback *tb_next;
-    struct _frame *tb_frame;
+    PyFrameObject *tb_frame;
     int tb_lasti;
     int tb_lineno;
 } PyTracebackObject;

Include/frameobject.h

@@ -6,9 +6,7 @@
 extern "C" {
 #endif
 
-/* There are currently no frame related APIs in the stable ABI
- * (they're all in the full CPython-specific API)
- */
+#include "pyframe.h"
 
 #ifndef Py_LIMITED_API
 #  define Py_CPYTHON_FRAMEOBJECT_H

Include/genobject.h

@@ -10,14 +10,12 @@ extern "C" {
 
 #include "pystate.h"   /* _PyErr_StackItem */
 
-struct _frame; /* Avoid including frameobject.h */
-
 /* _PyGenObject_HEAD defines the initial segment of generator
    and coroutine objects. */
 #define _PyGenObject_HEAD(prefix)                                           \
     PyObject_HEAD                                                           \
     /* Note: gi_frame can be NULL if the generator is "finished" */         \
-    struct _frame *prefix##_frame;                                          \
+    PyFrameObject *prefix##_frame;                                          \
     /* True if generator is being executed. */                              \
     char prefix##_running;                                                  \
     /* The code object backing the generator */                             \
@@ -40,8 +38,8 @@ PyAPI_DATA(PyTypeObject) PyGen_Type;
 #define PyGen_Check(op) PyObject_TypeCheck(op, &PyGen_Type)
 #define PyGen_CheckExact(op) Py_IS_TYPE(op, &PyGen_Type)
 
-PyAPI_FUNC(PyObject *) PyGen_New(struct _frame *);
-PyAPI_FUNC(PyObject *) PyGen_NewWithQualName(struct _frame *,
+PyAPI_FUNC(PyObject *) PyGen_New(PyFrameObject *);
+PyAPI_FUNC(PyObject *) PyGen_NewWithQualName(PyFrameObject *,
     PyObject *name, PyObject *qualname);
 PyAPI_FUNC(int) _PyGen_SetStopIterationValue(PyObject *);
 PyAPI_FUNC(int) _PyGen_FetchStopIterationValue(PyObject **);
@@ -60,7 +58,7 @@ PyAPI_DATA(PyTypeObject) _PyCoroWrapper_Type;
 
 #define PyCoro_CheckExact(op) Py_IS_TYPE(op, &PyCoro_Type)
 PyObject *_PyCoro_GetAwaitableIter(PyObject *o);
-PyAPI_FUNC(PyObject *) PyCoro_New(struct _frame *,
+PyAPI_FUNC(PyObject *) PyCoro_New(PyFrameObject *,
     PyObject *name, PyObject *qualname);
 
 /* Asynchronous Generators */
@@ -86,7 +84,7 @@ PyAPI_DATA(PyTypeObject) _PyAsyncGenASend_Type;
 PyAPI_DATA(PyTypeObject) _PyAsyncGenWrappedValue_Type;
 PyAPI_DATA(PyTypeObject) _PyAsyncGenAThrow_Type;
 
-PyAPI_FUNC(PyObject *) PyAsyncGen_New(struct _frame *,
+PyAPI_FUNC(PyObject *) PyAsyncGen_New(PyFrameObject *,
     PyObject *name, PyObject *qualname);
 
 #define PyAsyncGen_CheckExact(op) Py_IS_TYPE(op, &PyAsyncGen_Type)