From 4c6afbcb01d1cae72d829af5301df5f592fa2079 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 30 Jul 2024 10:16:19 -0300
Subject: [PATCH] Struct 'transferinfo' moved to "lua_State"

That reduces the size of "CallInfo". Moreover, bit CIST_HOOKED from
call status is not needed. When in a hook, 'transferinfo' is always
valid, being zero when the hook is not call/return.
---
 ldebug.c |  6 +++---
 ldo.c    | 14 +++++---------
 lstate.h | 20 ++++++++------------
 3 files changed, 16 insertions(+), 24 deletions(-)

diff --git a/ldebug.c b/ldebug.c
index a3a536bb..9e341f11 100644
--- a/ldebug.c
+++ b/ldebug.c
@@ -364,11 +364,11 @@ static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
         break;
       }
       case 'r': {
-        if (ci == NULL || !(ci->callstatus & CIST_TRAN))
+        if (ci == NULL || !(ci->callstatus & CIST_HOOKED))
           ar->ftransfer = ar->ntransfer = 0;
         else {
-          ar->ftransfer = ci->u2.transferinfo.ftransfer;
-          ar->ntransfer = ci->u2.transferinfo.ntransfer;
+          ar->ftransfer = L->transferinfo.ftransfer;
+          ar->ntransfer = L->transferinfo.ntransfer;
         }
         break;
       }
diff --git a/ldo.c b/ldo.c
index 1d1b7a71..d63c8267 100644
--- a/ldo.c
+++ b/ldo.c
@@ -357,7 +357,6 @@ void luaD_hook (lua_State *L, int event, int line,
                               int ftransfer, int ntransfer) {
   lua_Hook hook = L->hook;
   if (hook && L->allowhook) {  /* make sure there is a hook */
-    unsigned mask = CIST_HOOKED;
     CallInfo *ci = L->ci;
     ptrdiff_t top = savestack(L, L->top.p);  /* preserve original 'top' */
     ptrdiff_t ci_top = savestack(L, ci->top.p);  /* idem for 'ci->top' */
@@ -365,18 +364,15 @@ void luaD_hook (lua_State *L, int event, int line,
     ar.event = event;
     ar.currentline = line;
     ar.i_ci = ci;
-    if (ntransfer != 0) {
-      mask |= CIST_TRAN;  /* 'ci' has transfer information */
-      ci->u2.transferinfo.ftransfer = ftransfer;
-      ci->u2.transferinfo.ntransfer = ntransfer;
-    }
+    L->transferinfo.ftransfer = ftransfer;
+    L->transferinfo.ntransfer = ntransfer;
     if (isLua(ci) && L->top.p < ci->top.p)
       L->top.p = ci->top.p;  /* protect entire activation register */
     luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
     if (ci->top.p < L->top.p + LUA_MINSTACK)
       ci->top.p = L->top.p + LUA_MINSTACK;
     L->allowhook = 0;  /* cannot call hooks inside a hook */
-    ci->callstatus |= mask;
+    ci->callstatus |= CIST_HOOKED;
     lua_unlock(L);
     (*hook)(L, &ar);
     lua_lock(L);
@@ -384,7 +380,7 @@ void luaD_hook (lua_State *L, int event, int line,
     L->allowhook = 1;
     ci->top.p = restorestack(L, ci_top);
     L->top.p = restorestack(L, top);
-    ci->callstatus &= ~mask;
+    ci->callstatus &= ~CIST_HOOKED;
   }
 }
 
@@ -525,7 +521,7 @@ void luaD_poscall (lua_State *L, CallInfo *ci, int nres) {
   moveresults(L, ci->func.p, nres, fwanted);
   /* function cannot be in any of these cases when returning */
   lua_assert(!(ci->callstatus &
-        (CIST_HOOKED | CIST_YPCALL | CIST_FIN | CIST_TRAN | CIST_CLSRET)));
+        (CIST_HOOKED | CIST_YPCALL | CIST_FIN | CIST_CLSRET)));
   L->ci = ci->previous;  /* back to caller (after closing variables) */
 }
 
diff --git a/lstate.h b/lstate.h
index aa9687ae..e12ca154 100644
--- a/lstate.h
+++ b/lstate.h
@@ -183,8 +183,6 @@ typedef struct stringtable {
 ** yield (from the yield until the next resume);
 ** - field 'nres' is used only while closing tbc variables when
 ** returning from a function;
-** - field 'transferinfo' is used only during call/returnhooks,
-** before the function starts or after it ends.
 */
 struct CallInfo {
   StkIdRel func;  /* function index in the stack */
@@ -206,10 +204,6 @@ struct CallInfo {
     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) */
-      int ftransfer;  /* offset of first value transferred */
-      int ntransfer;  /* number of values transferred */
-    } transferinfo;
   } u2;
   l_uint32 callstatus;
 };
@@ -236,15 +230,13 @@ struct CallInfo {
 #define CIST_HOOKYIELD	(cast(l_uint32, 1) << 14)
 /* function "called" a finalizer */
 #define CIST_FIN	(cast(l_uint32, 1) << 15)
-/* 'ci' has transfer information */
-#define CIST_TRAN	(cast(l_uint32, 1) << 16)
  /* function is closing tbc variables */
-#define CIST_CLSRET	(cast(l_uint32, 1) << 17)
-/* Bits 18-20 are used for CIST_RECST (see below) */
-#define CIST_RECST	18  /* the offset, not the mask */
+#define CIST_CLSRET	(cast(l_uint32, 1) << 16)
+/* Bits 17-19 are used for CIST_RECST (see below) */
+#define CIST_RECST	17  /* the offset, not the mask */
 #if defined(LUA_COMPAT_LT_LE)
 /* using __lt for __le */
-#define CIST_LEQ	(cast(l_uint32, 1) << 21)
+#define CIST_LEQ	(cast(l_uint32, 1) << 20)
 #endif
 
 
@@ -354,6 +346,10 @@ struct lua_State {
   int basehookcount;
   int hookcount;
   volatile l_signalT hookmask;
+  struct {  /* info about transferred values (for call/return hooks) */
+    int ftransfer;  /* offset of first value transferred */
+    int ntransfer;  /* number of values transferred */
+  } transferinfo;
 };