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The C and C++ Include Header Files

cat -n /usr/include/python3.14/internal/pycore_emscripten_trampoline.h

     1	#ifndef Py_EMSCRIPTEN_TRAMPOLINE_H
     2	#define Py_EMSCRIPTEN_TRAMPOLINE_H
     3	
     4	#include "pycore_typedefs.h"      // _PyRuntimeState
     5	
     6	/**
     7	 * C function call trampolines to mitigate bad function pointer casts.
     8	 *
     9	 * Section 6.3.2.3, paragraph 8 reads:
    10	 *
    11	 *      A pointer to a function of one type may be converted to a pointer to a
    12	 *      function of another type and back again; the result shall compare equal to
    13	 *      the original pointer. If a converted pointer is used to call a function
    14	 *      whose type is not compatible with the pointed-to type, the behavior is
    15	 *      undefined.
    16	 *
    17	 * Typical native ABIs ignore additional arguments or fill in missing values
    18	 * with 0/NULL in function pointer cast. Compilers do not show warnings when a
    19	 * function pointer is explicitly casted to an incompatible type.
    20	 *
    21	 * Bad fpcasts are an issue in WebAssembly. WASM's indirect_call has strict
    22	 * function signature checks. Argument count, types, and return type must match.
    23	 *
    24	 * Third party code unintentionally rely on problematic fpcasts. The call
    25	 * trampoline mitigates common occurrences of bad fpcasts on Emscripten.
    26	 */
    27	
    28	#if defined(__EMSCRIPTEN__) && defined(PY_CALL_TRAMPOLINE)
    29	
    30	PyObject*
    31	_PyEM_TrampolineCall(PyCFunctionWithKeywords func,
    32	                     PyObject* self,
    33	                     PyObject* args,
    34	                     PyObject* kw);
    35	
    36	#define _PyCFunction_TrampolineCall(meth, self, args) \
    37	    _PyEM_TrampolineCall(*_PyCFunctionWithKeywords_CAST(meth), (self), (args), NULL)
    38	
    39	#define _PyCFunctionWithKeywords_TrampolineCall(meth, self, args, kw) \
    40	    _PyEM_TrampolineCall((meth), (self), (args), (kw))
    41	
    42	#define descr_set_trampoline_call(set, obj, value, closure)                 \
    43	    ((int)_PyEM_TrampolineCall(_PyCFunctionWithKeywords_CAST(set), (obj),   \
    44	                               (value), (PyObject*)(closure)))
    45	
    46	#define descr_get_trampoline_call(get, obj, closure)                \
    47	    _PyEM_TrampolineCall(_PyCFunctionWithKeywords_CAST(get), (obj), \
    48	                         (PyObject*)(closure), NULL)
    49	
    50	
    51	#else // defined(__EMSCRIPTEN__) && defined(PY_CALL_TRAMPOLINE)
    52	
    53	#define _PyCFunction_TrampolineCall(meth, self, args) \
    54	    (meth)((self), (args))
    55	
    56	#define _PyCFunctionWithKeywords_TrampolineCall(meth, self, args, kw) \
    57	    (meth)((self), (args), (kw))
    58	
    59	#define descr_set_trampoline_call(set, obj, value, closure) \
    60	    (set)((obj), (value), (closure))
    61	
    62	#define descr_get_trampoline_call(get, obj, closure) \
    63	    (get)((obj), (closure))
    64	
    65	#endif // defined(__EMSCRIPTEN__) && defined(PY_CALL_TRAMPOLINE)
    66	
    67	#endif // ndef Py_EMSCRIPTEN_SIGNAL_H