gh-129666: Add C11/C++11 to docs and -pedantic-errors to GCC/clang test_c[pp]ext tests (GH-130692)

Disable pedantic check for c++03 (unlimited API)

Also add a check for c++03 *limited* API, which passes in pedantic mode
after removing a comma in the `PySendResult` declaration, and allowing
`long long`.
This commit is contained in:
Petr Viktorin 2025-03-04 14:10:09 +01:00 committed by GitHub
parent 6c48ed7d62
commit d91cc9db15
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
8 changed files with 75 additions and 1 deletions

View file

@ -30,6 +30,16 @@ familiar with writing an extension before attempting to embed Python in a real
application.
Language version compatibility
==============================
Python's C API is compatible with C11 and C++11 versions of C and C++.
This is a lower limit: the C API does not require features from later
C/C++ versions.
You do *not* need to enable your compiler's "c11 mode".
Coding standards
================

View file

@ -683,7 +683,7 @@ PyAPI_DATA(PyObject) _Py_NotImplementedStruct; /* Don't use this directly */
typedef enum {
PYGEN_RETURN = 0,
PYGEN_ERROR = -1,
PYGEN_NEXT = 1,
PYGEN_NEXT = 1
} PySendResult;
#endif

View file

@ -38,6 +38,9 @@ class TestExt(unittest.TestCase):
@unittest.skipIf(support.MS_WINDOWS, "MSVC doesn't support /std:c99")
def test_build_c99(self):
# In public docs, we say C API is compatible with C11. However,
# in practice we do maintain C99 compatibility in public headers.
# Please ask the C API WG before adding a new C11-only feature.
self.check_build('_test_c99_cext', std='c99')
@support.requires_gil_enabled('incompatible with Free Threading')

View file

@ -58,11 +58,24 @@ _testcext_exec(
return 0;
}
// Converting from function pointer to void* has undefined behavior, but
// works on all known platforms, and CPython's module and type slots currently
// need it.
// (GCC doesn't have a narrower category for this than -Wpedantic.)
_Py_COMP_DIAG_PUSH
#if defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wpedantic"
#elif defined(__clang__)
#pragma clang diagnostic ignored "-Wpedantic"
#endif
static PyModuleDef_Slot _testcext_slots[] = {
{Py_mod_exec, (void*)_testcext_exec},
{0, NULL}
};
_Py_COMP_DIAG_POP
PyDoc_STRVAR(_testcext_doc, "C test extension.");

View file

@ -21,6 +21,9 @@ if not support.MS_WINDOWS:
# gh-120593: Check the 'const' qualifier
'-Wcast-qual',
# Ask for strict(er) compliance with the standard
'-pedantic-errors',
]
if not support.Py_GIL_DISABLED:
CFLAGS.append(

View file

@ -29,8 +29,15 @@ class TestCPPExt(unittest.TestCase):
self.check_build('_testcppext')
def test_build_cpp03(self):
# In public docs, we say C API is compatible with C++11. However,
# in practice we do maintain C++03 compatibility in public headers.
# Please ask the C API WG before adding a new C++11-only feature.
self.check_build('_testcpp03ext', std='c++03')
@support.requires_gil_enabled('incompatible with Free Threading')
def test_build_limited_cpp03(self):
self.check_build('_test_limited_cpp03ext', std='c++03', limited=True)
@unittest.skipIf(support.MS_WINDOWS, "MSVC doesn't support /std:c++11")
def test_build_cpp11(self):
self.check_build('_testcpp11ext', std='c++11')

View file

@ -161,11 +161,24 @@ private:
int VirtualPyObject::instance_count = 0;
// Converting from function pointer to void* has undefined behavior, but
// works on all known platforms, and CPython's module and type slots currently
// need it.
// (GCC doesn't have a narrower category for this than -Wpedantic.)
_Py_COMP_DIAG_PUSH
#if defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wpedantic"
#elif defined(__clang__)
#pragma clang diagnostic ignored "-Wpedantic"
#endif
PyType_Slot VirtualPyObject_Slots[] = {
{Py_tp_free, (void*)VirtualPyObject::dealloc},
{0, _Py_NULL},
};
_Py_COMP_DIAG_POP
PyType_Spec VirtualPyObject_Spec = {
/* .name */ STR(MODULE_NAME) ".VirtualPyObject",
/* .basicsize */ sizeof(VirtualPyObject),
@ -241,11 +254,20 @@ _testcppext_exec(PyObject *module)
return 0;
}
// Need to ignore "-Wpedantic" warnings; see VirtualPyObject_Slots above
_Py_COMP_DIAG_PUSH
#if defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wpedantic"
#elif defined(__clang__)
#pragma clang diagnostic ignored "-Wpedantic"
#endif
static PyModuleDef_Slot _testcppext_slots[] = {
{Py_mod_exec, reinterpret_cast<void*>(_testcppext_exec)},
{0, _Py_NULL}
};
_Py_COMP_DIAG_POP
PyDoc_STRVAR(_testcppext_doc, "C++ test extension.");

View file

@ -19,6 +19,17 @@ if not support.MS_WINDOWS:
# warnings
'-Werror',
]
CPPFLAGS_PEDANTIC = [
# Ask for strict(er) compliance with the standard.
# We cannot do this for c++03 unlimited API, since several headers in
# Include/cpython/ use commas at end of `enum` declarations, a C++11
# feature for which GCC has no narrower option than -Wpedantic itself.
'-pedantic-errors',
# We also use `long long`, a C++11 feature we can enable individually.
'-Wno-long-long',
]
else:
# MSVC compiler flags
CPPFLAGS = [
@ -27,6 +38,7 @@ else:
# Treat all compiler warnings as compiler errors
'/WX',
]
CPPFLAGS_PEDANTIC = []
def main():
@ -45,6 +57,10 @@ def main():
else:
cppflags.append(f'-std={std}')
if limited or (std != 'c++03'):
# See CPPFLAGS_PEDANTIC docstring
cppflags.extend(CPPFLAGS_PEDANTIC)
# gh-105776: When "gcc -std=11" is used as the C++ compiler, -std=c11
# option emits a C++ compiler warning. Remove "-std11" option from the
# CC command.