[Tarantool-patches] [PATCH luajit 5/5] FFI/MacOS: Fix calling convention for enums.

[Sergey Kaplun via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

From: Mike Pall <mike>

Thanks to Sergey Kaplun.

(cherry picked from commit b925b3e3fc6771171602323b45fbe9fb8fc90369)

This patch fixes the regression in the arm64 OSX FFI behaviour when the
fundamental C types are passed via the stack. The given arguments should
occupy the "packed" size on the stack if they are fundamental C
types [1]. Structures require the pointer-size alignment like it was done
in the previous commit. This patch fixes that (not only for enums but for
other data types too). This fixes the tests that were failing after the
previous commit.

[1]: https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms#Pass-arguments-to-functions-correctly

Sergey Kaplun:
* added the description for the problem

Part of tarantool/tarantool#12480
---
 src/lj_ccall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lj_ccall.c b/src/lj_ccall.c
index 1beccc10..7c3ec1e5 100644
--- a/src/lj_ccall.c
+++ b/src/lj_ccall.c
@@ -1082,7 +1082,7 @@ static int ccall_set_args(lua_State *L, CTState *cts, CType *ct,
     if (CCALL_ALIGN_STACKARG) {  /* Align argument on stack. */
       MSize align = (1u << ctype_align(ccall_struct_align(cts, d))) - 1;
 #if LJ_TARGET_ARM64 && LJ_TARGET_OSX
-      isva = 1;
+      isva = ctype_isstruct(d->info);
 #endif
       if (rp || (CCALL_PACK_STACKARG && isva && align < CTSIZE_PTR-1))
 	align = CTSIZE_PTR-1;
-- 
2.54.0