Compilation failure OSX, 3.2.8

[bazineta]

This declaration doesn't work with clang on OSX:

#define mi_stats_t_decl(name)  mi_stats_t name = { 0 }; name.size = sizeof(mi_stats_t); name.version = MI_STAT_VERSION;

It yields this:

mimalloc-3.2.8/src/stats.c:485:3: error: missing field 'version' initializer [-Werror,-Wmissing-field-initializers]
  485 |   mi_stats_t_decl(stats);
      |   ^
mimalloc-3.2.8/include/mimalloc-stats.h:119:54: note: expanded from macro 'mi_stats_t_decl'
  119 | #define mi_stats_t_decl(name)  mi_stats_t name = { 0 }; name.size = sizeof(mi_stats_t); name.version = MI_STAT_VERSION;

Attempted workaround using C99 designated initializers, which is also compatible with C++20.

#define mi_stats_t_decl(name) \
  mi_stats_t name = { .size = sizeof(mi_stats_t), .version = MI_STAT_VERSION }; 

However, testing various levels of clang alone, that's seemingly not a viable option; some levels are happy with it, others demand that the entire struct be initialized. Therefore, the following is the best I've come up with so far:

#define mi_stats_t_decl(name)              \
  mi_stats_t name;                         \
  memset(&name, 0, sizeof(mi_stats_t));    \
  name.size    = sizeof(mi_stats_t);       \
  name.version = MI_STAT_VERSION;

Which I'd characterize as 'ick', but perhaps someone else will have a better idea.

[res2k]

Shouldn't the following also give the desired result?:

#define mi_stats_t_decl(name)  mi_stats_t name = { sizeof(mi_stats_t), MI_STAT_VERSION };

...or does it just result in clang complaining about the other fields not being initialized?

[bazineta]

Not portably, unfortunately. Even within clang, some levels will accept it, others will complain about the other fields not being initialized. I haven't tried other compilers, since I'm already falling down on clang alone here, but I suspect the answer would be 'it depends'.