Since gh-158080 (GH-158085), PyStatus.exitcode is declared with Py_DEPRECATED(3.16) in Include/cpython/initconfig.h. Because the C API passes and returns PyStatus by value (PyStatus_Exception(), PyStatus_IsError(), Py_InitializeFromConfig(), ...), C++ code that uses the API in the documented way makes clang generate the implicit copy constructor / move assignment operator of PyStatus. These use the deprecated member, so clang emits -Wdeprecated-declarations even though the code never touches exitcode. With -Werror, the build fails.
The usage pattern of the Doc/c-api/init_config.rst examples (ex: init_python()), compiled as C++, is enough to reproduce:
#include<Python.h>intmain(int argc, char** argv) {
PyStatus status;
PyConfig config;
PyConfig_InitPythonConfig(&config);
status = PyConfig_SetBytesString(&config, &config.program_name, argv[0]);
if (PyStatus_Exception(status)) {
goto exception;
}
status = Py_InitializeFromConfig(&config);
if (PyStatus_Exception(status)) {
goto exception;
}
PyConfig_Clear(&config);
returnPy_RunMain();
exception:
PyConfig_Clear(&config);
Py_ExitStatusException(status);
}
$ clang++ -std=c++17 -Wall -Werror -I<cpython>/Include -I<build> -c embed.cpp
Include/cpython/initconfig.h:10:9: error: 'exitcode' is deprecated [-Werror,-Wdeprecated-declarations]
embed.cpp:7:12: note: in implicit move assignment operator for 'PyStatus' first required here
Include/cpython/initconfig.h:10:9: error: 'exitcode' is deprecated [-Werror,-Wdeprecated-declarations]
Include/cpython/initconfig.h:10:9: error: 'exitcode' is deprecated [-Werror,-Wdeprecated-declarations]
embed.cpp:8:28: note: in implicit copy constructor for 'PyStatus' first required here
Reproduced with 3.16.0a1, with Ubuntu clang 21.1.8 (Linux aarch64) and Apple clang 21.0.0 (macOS arm64); the PyStatus definition is unchanged on current main.
g++ 15, and clang compiling the same file as C, emit no warning.
The diagnostic is reported at the definition of the structure in initconfig.h, so users cannot silence it locally with a pragma around their own calls; they have to wrap the #include <Python.h> itself.
Possible fix
Suppress the warning around the definition of the structure, with the existing _Py_COMP_DIAG_* macros of pyport.h:
With this change the example above compiles cleanly with clang++ -Werror, while real uses (status.exitcode, PyStatus_Exit(), PyStatus_IsExit()) still emit the deprecation warning. (Alternatively, only the functions could be marked deprecated and the member documented as deprecated.)
A C++ test in Lib/test/test_cppext that copies a PyStatus would catch regressions of this kind.
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