Janitorial work
Comments, code details, identation.
diff --git a/lapi.c b/lapi.c
index 3583e9c..163533a 100644
--- a/lapi.c
+++ b/lapi.c
@@ -74,7 +74,8 @@
return &G(L)->nilvalue; /* it has no upvalues */
else {
CClosure *func = clCvalue(s2v(ci->func));
- return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : &G(L)->nilvalue;
+ return (idx <= func->nupvalues) ? &func->upvalue[idx-1]
+ : &G(L)->nilvalue;
}
}
}
diff --git a/lbaselib.c b/lbaselib.c
index 747fd45..60786b3 100644
--- a/lbaselib.c
+++ b/lbaselib.c
@@ -182,7 +182,8 @@
static int pushmode (lua_State *L, int oldmode) {
- lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental" : "generational");
+ lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental"
+ : "generational");
return 1;
}
diff --git a/ldo.c b/ldo.c
index 57d4f7d..9076c0e 100644
--- a/ldo.c
+++ b/ldo.c
@@ -295,8 +295,8 @@
if (hook && L->allowhook) { /* make sure there is a hook */
int mask = CIST_HOOKED;
CallInfo *ci = L->ci;
- ptrdiff_t top = savestack(L, L->top);
- ptrdiff_t ci_top = savestack(L, ci->top);
+ ptrdiff_t top = savestack(L, L->top); /* preserve original 'top' */
+ ptrdiff_t ci_top = savestack(L, ci->top); /* idem for 'ci->top' */
lua_Debug ar;
ar.event = event;
ar.currentline = line;
@@ -307,7 +307,7 @@
ci->u2.transferinfo.ntransfer = ntransfer;
}
luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
- if (L->top + LUA_MINSTACK > ci->top)
+ if (ci->top < L->top + LUA_MINSTACK)
ci->top = L->top + LUA_MINSTACK;
L->allowhook = 0; /* cannot call hooks inside a hook */
ci->callstatus |= mask;
@@ -329,39 +329,44 @@
** active.
*/
void luaD_hookcall (lua_State *L, CallInfo *ci) {
- int hook = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL : LUA_HOOKCALL;
- Proto *p;
- if (!(L->hookmask & LUA_MASKCALL)) /* some other hook? */
- return; /* don't call hook */
- p = clLvalue(s2v(ci->func))->p;
- L->top = ci->top; /* prepare top */
- ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */
- luaD_hook(L, hook, -1, 1, p->numparams);
- ci->u.l.savedpc--; /* correct 'pc' */
+ if (L->hookmask & LUA_MASKCALL) { /* is call hook on? */
+ int event = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL
+ : LUA_HOOKCALL;
+ Proto *p = ci_func(ci)->p;
+ L->top = ci->top; /* prepare top */
+ ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */
+ luaD_hook(L, event, -1, 1, p->numparams);
+ ci->u.l.savedpc--; /* correct 'pc' */
+ }
}
+/*
+** Executes a call hook for Lua and C functions. This function is called
+** whenever 'hookmask' is not zero, so it checks whether return hooks are
+** active.
+*/
static void rethook (lua_State *L, CallInfo *ci, int nres) {
- StkId firstres = L->top - nres; /* index of first result */
- ptrdiff_t oldtop = savestack(L, L->top); /* hook may change top */
- int delta = 0;
- if (isLuacode(ci)) {
- Proto *p = ci_func(ci)->p;
- if (p->is_vararg)
- delta = ci->u.l.nextraargs + p->numparams + 1;
+ if (L->hookmask & LUA_MASKRET) { /* is return hook on? */
+ StkId firstres = L->top - nres; /* index of first result */
+ ptrdiff_t oldtop = savestack(L, L->top); /* hook may change top */
+ int delta = 0; /* correction for vararg functions */
+ int ftransfer;
+ if (isLuacode(ci)) {
+ Proto *p = ci_func(ci)->p;
+ if (p->is_vararg)
+ delta = ci->u.l.nextraargs + p->numparams + 1;
if (L->top < ci->top)
L->top = ci->top; /* correct top to run hook */
- }
- if (L->hookmask & LUA_MASKRET) { /* is return hook on? */
- int ftransfer;
+ }
ci->func += delta; /* if vararg, back to virtual 'func' */
ftransfer = cast(unsigned short, firstres - ci->func);
luaD_hook(L, LUA_HOOKRET, -1, ftransfer, nres); /* call it */
ci->func -= delta;
+ L->top = restorestack(L, oldtop);
}
if (isLua(ci = ci->previous))
L->oldpc = pcRel(ci->u.l.savedpc, ci_func(ci)->p); /* update 'oldpc' */
- L->top = restorestack(L, oldtop);
}
@@ -420,7 +425,9 @@
}
firstresult = L->top - nres; /* index of first result */
/* move all results to correct place */
- for (i = 0; i < nres && i < wanted; i++)
+ if (nres > wanted)
+ nres = wanted; /* don't need more than that */
+ for (i = 0; i < nres; i++)
setobjs2s(L, res + i, firstresult + i);
for (; i < wanted; i++) /* complete wanted number of results */
setnilvalue(s2v(res + i));
diff --git a/lstate.h b/lstate.h
index 65d4526..f3d791a 100644
--- a/lstate.h
+++ b/lstate.h
@@ -156,6 +156,16 @@
/*
** Information about a call.
+** About union 'u':
+** - field 'l' is used only for Lua functions;
+** - field 'c' is used only for C functions.
+** About union 'u2':
+** - field 'funcidx' is used only by C functions while doing a
+** protected call;
+** - field 'nyield' is used only while a function is "doing" an
+** yield (from the yield until the next resume);
+** - field 'transferinfo' is used only during call/returnhooks,
+** before the function starts or after it ends.
*/
typedef struct CallInfo {
StkId func; /* function index in the stack */
