py/obj: Fix mp_obj_is_type compilation with C++.

Fixes issue #12951.

Signed-off-by: stijn <stijn@ignitron.net>
This commit is contained in:
stijn 2023-11-13 16:04:40 +01:00 committed by Damien George
parent 92741a3438
commit a968888f69
3 changed files with 19 additions and 7 deletions

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@ -1,9 +1,16 @@
extern "C" {
#include <examplemodule.h>
#include <py/objstr.h>
// Here we implement the function using C++ code, but since it's
// declaration has to be compatible with C everything goes in extern "C" scope.
mp_obj_t cppfunc(mp_obj_t a_obj, mp_obj_t b_obj) {
// The following no-ops are just here to verify the static assertions used in
// the public API all compile with C++.
MP_STATIC_ASSERT_STR_ARRAY_COMPATIBLE;
if (mp_obj_is_type(a_obj, &mp_type_BaseException)) {
}
// Prove we have (at least) C++11 features.
const auto a = mp_obj_get_int(a_obj);
const auto b = mp_obj_get_int(b_obj);

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@ -52,10 +52,15 @@ typedef unsigned int uint;
// Static assertion macro
#define MP_STATIC_ASSERT(cond) ((void)sizeof(char[1 - 2 * !(cond)]))
#if defined(_MSC_VER)
#define MP_STATIC_ASSERT_NOT_MSC(cond) (1)
// In C++ things like comparing extern const pointers are not constant-expressions so cannot be used
// in MP_STATIC_ASSERT. Note that not all possible compiler versions will reject this. Some gcc versions
// do, others only with -Werror=vla, msvc always does.
// The (void) is needed to avoid "left operand of comma operator has no effect [-Werror=unused-value]"
// when using this macro on the left-hand side of a comma.
#if defined(_MSC_VER) || defined(__cplusplus)
#define MP_STATIC_ASSERT_NONCONSTEXPR(cond) ((void)1)
#else
#define MP_STATIC_ASSERT_NOT_MSC(cond) MP_STATIC_ASSERT(cond)
#define MP_STATIC_ASSERT_NONCONSTEXPR(cond) MP_STATIC_ASSERT(cond)
#endif
// Round-up integer division

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@ -928,10 +928,10 @@ void *mp_obj_malloc_helper(size_t num_bytes, const mp_obj_type_t *type);
// optimizations (other tricks like using ({ expr; exper; }) or (exp, expr, expr) in mp_obj_is_type() result
// in missed optimizations)
#define mp_type_assert_not_bool_int_str_nonetype(t) ( \
MP_STATIC_ASSERT_NOT_MSC((t) != &mp_type_bool), assert((t) != &mp_type_bool), \
MP_STATIC_ASSERT_NOT_MSC((t) != &mp_type_int), assert((t) != &mp_type_int), \
MP_STATIC_ASSERT_NOT_MSC((t) != &mp_type_str), assert((t) != &mp_type_str), \
MP_STATIC_ASSERT_NOT_MSC((t) != &mp_type_NoneType), assert((t) != &mp_type_NoneType), \
MP_STATIC_ASSERT_NONCONSTEXPR((t) != &mp_type_bool), assert((t) != &mp_type_bool), \
MP_STATIC_ASSERT_NONCONSTEXPR((t) != &mp_type_int), assert((t) != &mp_type_int), \
MP_STATIC_ASSERT_NONCONSTEXPR((t) != &mp_type_str), assert((t) != &mp_type_str), \
MP_STATIC_ASSERT_NONCONSTEXPR((t) != &mp_type_NoneType), assert((t) != &mp_type_NoneType), \
1)
#define mp_obj_is_type(o, t) (mp_type_assert_not_bool_int_str_nonetype(t) && mp_obj_is_exact_type(o, t))