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| author | Thomas Haller <thaller@redhat.com> | 2021-01-14 11:43:39 +0100 |
|---|---|---|
| committer | Thomas Haller <thaller@redhat.com> | 2021-03-08 22:29:00 +0100 |
| commit | 45ba49f322abc0e0fca7abda33778742fecad4ce (patch) | |
| tree | 88f7bfb3948c7eb6519076954a88130cbc9b3ffc | |
| parent | 098ac7dbc0a7f8847d357f9e25aec929237f745f (diff) | |
| download | NetworkManager-45ba49f322abc0e0fca7abda33778742fecad4ce.tar.gz | |
shared: add nm_vsprintf_buf_or_alloc() macro
| -rw-r--r-- | src/libnm-glib-aux/nm-macros-internal.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/src/libnm-glib-aux/nm-macros-internal.h b/src/libnm-glib-aux/nm-macros-internal.h index 3f45cfaea2..37dde0173b 100644 --- a/src/libnm-glib-aux/nm-macros-internal.h +++ b/src/libnm-glib-aux/nm-macros-internal.h @@ -1733,6 +1733,54 @@ nm_decode_version(guint version, guint *major, guint *minor, guint *micro) _buf; \ }) +#define nm_vsprintf_buf_or_alloc(format, va_last_arg, sbuf_stack, out_sbuf_heap, out_len) \ + ({ \ + const char *const _format = (format); \ + char *const _sbuf_stack = (sbuf_stack); \ + char **const _out_sbuf_heap = (out_sbuf_heap); \ + gsize *const _out_len = (out_len); \ + const char * _msg; \ + va_list _va_args; \ + int _l; \ + \ + G_STATIC_ASSERT_EXPR(G_N_ELEMENTS(sbuf_stack) > sizeof(_sbuf_stack)); \ + \ + va_start(_va_args, va_last_arg); \ + _l = g_vsnprintf(_sbuf_stack, sizeof(sbuf_stack), _format, _va_args); \ + va_end(_va_args); \ + \ + nm_assert(_l >= 0 && _l < G_MAXINT); \ + \ + if ((gsize) _l >= sizeof(sbuf_stack)) { \ + const gsize _l2 = ((gsize) _l) + 1u; \ + char * _sbuf_heap; \ + \ + /* Don't use g_strdup_vprintf() here either, because that also needs + * to first determine the length (which is commonly does by printing + * to a stack allocated buffer of size 1. We already know the required + * size. */ \ + \ + _sbuf_heap = g_malloc(_l2); \ + \ + va_start(_va_args, va_last_arg); \ + _l = g_vsnprintf(_sbuf_heap, _l2, _format, _va_args); \ + va_end(_va_args); \ + \ + nm_assert(_l >= 0 && ((gsize) _l) == _l2 - 1u); \ + \ + _msg = _sbuf_heap; \ + *_out_sbuf_heap = _sbuf_heap; \ + } else { \ + _msg = _sbuf_stack; \ + *_out_sbuf_heap = NULL; \ + } \ + \ + nm_assert(strlen(_msg) == (gsize) _l); \ + NM_SET_OUT(_out_len, (gsize) _l); \ + \ + _msg; \ + }) + /* it is "unsafe" because @bufsize must not be a constant expression and * there is no check at compiletime. Regardless of that, the buffer size * must not be larger than 300 bytes, as this gets stack allocated. */ |