'__close' methods can yield in the return of a C function

When, inside a coroutine, a C function with to-be-closed slots return,
the corresponding metamethods can yield. ('__close' metamethods called
through 'lua_closeslot' still cannot yield, as there is no continuation
to go when resuming.)

1 files changed, 8 insertions, 4 deletions

diff --git a/lstate.h b/lstate.h
index b6ade7c7..0322e2c6 100644
--- a/lstate.h
+++ b/lstate.h
@@ -164,6 +164,8 @@ typedef struct stringtable {
 ** protected call;
 ** - field 'nyield' is used only while a function is "doing" an
 ** yield (from the yield until the next resume);
+** - field 'nres' is used only while closing tbc variables when
+** returning from a C function;
 ** - field 'transferinfo' is used only during call/returnhooks,
 ** before the function starts or after it ends.
 */
@@ -186,6 +188,7 @@ typedef struct CallInfo {
   union {
     int funcidx;  /* called-function index */
     int nyield;  /* number of values yielded */
+    int nres;  /* number of values returned */
     struct {  /* info about transferred values (for call/return hooks) */
       unsigned short ftransfer;  /* offset of first value transferred */
       unsigned short ntransfer;  /* number of values transferred */
@@ -203,15 +206,16 @@ typedef struct CallInfo {
 #define CIST_C          (1<<1)  /* call is running a C function */
 #define CIST_FRESH      (1<<2)  /* call is on a fresh "luaV_execute" frame */
 #define CIST_HOOKED     (1<<3)  /* call is running a debug hook */
-#define CIST_YPCALL     (1<<4)  /* call is a yieldable protected call */
+#define CIST_YPCALL     (1<<4)  /* doing a yieldable protected call */
 #define CIST_TAIL       (1<<5)  /* call was tail called */
 #define CIST_HOOKYIELD  (1<<6)  /* last hook called yielded */
 #define CIST_FIN        (1<<7)  /* call is running a finalizer */
 #define CIST_TRAN       (1<<8)  /* 'ci' has transfer information */
-/* Bits 9-11 are used for CIST_RECST (see below) */
-#define CIST_RECST      9
+#define CIST_CLSRET     (1<<9)  /* function is closing tbc variables */
+/* Bits 10-12 are used for CIST_RECST (see below) */
+#define CIST_RECST      10
 #if defined(LUA_COMPAT_LT_LE)
-#define CIST_LEQ        (1<<12)  /* using __lt for __le */
+#define CIST_LEQ        (1<<13)  /* using __lt for __le */
 #endif