| From 2668390454bc0efe52a262eb2faa4a2bd5a062e2 Mon Sep 17 00:00:00 2001 |
| From: Philip Withnall <pwithnall@endlessos.org> |
| Date: Fri, 1 Apr 2022 13:47:19 +0100 |
| Subject: [PATCH 2/2] gatomic: Add a C++ variant of |
| g_atomic_int_compare_and_exchange() |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| The C++ variant implements type safety differently, to avoid warnings |
| from C++ compilers about: |
| ``` |
| ../../../gnome-commander-1.14.2/src/intviewer/searcher.cc:303:5: error: cannot initialize a parameter of type 'gint *' (aka 'int *') with an rvalue of type 'void *' |
| g_atomic_int_compare_and_exchange ((gint*)&src->priv->progress_value, oldval, (gint)d); |
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| /mnt/b/yoe/master/build/tmp/work/cortexa72-yoe-linux/gnome-commander/1.14.2-r0/recipe-sysroot/usr/include/glib-2.0/glib/gatomic.h:160:44: note: expanded from macro 'g_atomic_int_compare_and_exchange' |
| __atomic_compare_exchange_n ((atomic), (void *) (&(gaicae_oldval)), (newval), FALSE, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ? TRUE : FALSE; \ |
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| ``` |
| |
| This complements the existing C++ variant for |
| `g_atomic_pointer_compare_and_exchange()`, and fixes a regression on C++ |
| from https://gitlab.gnome.org/GNOME/glib/-/merge_requests/2114. |
| |
| With the addition of the unit tests in the previous commit, this is |
| effectively tested by the FreeBSD and macOS CI jobs, as they use |
| `clang++` in C++ mode. `g++` doesn’t seem to emit a warning about this. |
| |
| Signed-off-by: Philip Withnall <pwithnall@endlessos.org> |
| |
| Fixes: #2625 |
| Upstream-Status: Submitted [https://gitlab.gnome.org/GNOME/glib/-/merge_requests/2578] |
| Signed-off-by: Khem Raj <raj.khem@gmail.com> |
| --- |
| glib/gatomic.h | 12 ++++++++++++ |
| 1 file changed, 12 insertions(+) |
| |
| diff --git a/glib/gatomic.h b/glib/gatomic.h |
| index 5eba1dbc7..8b2b880c8 100644 |
| --- a/glib/gatomic.h |
| +++ b/glib/gatomic.h |
| @@ -152,6 +152,17 @@ G_END_DECLS |
| (void) (0 ? *(atomic) ^ *(atomic) : 1); \ |
| __atomic_fetch_sub ((atomic), 1, __ATOMIC_SEQ_CST) == 1; \ |
| })) |
| +#if defined(glib_typeof) && defined(__cplusplus) && __cplusplus >= 201103L |
| +/* See comments below about equivalent g_atomic_pointer_compare_and_exchange() |
| + * shenanigans for type-safety when compiling in C++ mode. */ |
| +#define g_atomic_int_compare_and_exchange(atomic, oldval, newval) \ |
| + (G_GNUC_EXTENSION ({ \ |
| + glib_typeof (*(atomic)) gaicae_oldval = (oldval); \ |
| + G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint)); \ |
| + (void) (0 ? *(atomic) ^ (newval) ^ (oldval) : 1); \ |
| + __atomic_compare_exchange_n ((atomic), &gaicae_oldval, (newval), FALSE, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ? TRUE : FALSE; \ |
| + })) |
| +#else /* if !(defined(glib_typeof) && defined(__cplusplus) && __cplusplus >= 201103L) */ |
| #define g_atomic_int_compare_and_exchange(atomic, oldval, newval) \ |
| (G_GNUC_EXTENSION ({ \ |
| gint gaicae_oldval = (oldval); \ |
| @@ -159,6 +170,7 @@ G_END_DECLS |
| (void) (0 ? *(atomic) ^ (newval) ^ (oldval) : 1); \ |
| __atomic_compare_exchange_n ((atomic), (void *) (&(gaicae_oldval)), (newval), FALSE, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ? TRUE : FALSE; \ |
| })) |
| +#endif /* defined(glib_typeof) */ |
| #define g_atomic_int_add(atomic, val) \ |
| (G_GNUC_EXTENSION ({ \ |
| G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint)); \ |
| -- |
| 2.35.1 |
| |