Fixed bugs of stack reallocation x GC

Macro 'checkstackGC' was doing a GC step after resizing the stack;
the GC could shrink the stack and undo the resize. Moreover, macro
'checkstackp' also does a GC step, which could remove the preallocated
CallInfo when calling a function. (Its name has been changed to
'checkstackGCp' to emphasize that it calls the GC.)
This commit is contained in:
Roberto Ierusalimschy
2020-07-07 18:03:48 -03:00
parent 314c6057b7
commit eb41999461
4 changed files with 14 additions and 11 deletions

13
ldo.c
View File

@@ -465,13 +465,13 @@ void luaD_call (lua_State *L, StkId func, int nresults) {
f = fvalue(s2v(func));
Cfunc: {
int n; /* number of returns */
CallInfo *ci = next_ci(L);
checkstackp(L, LUA_MINSTACK, func); /* ensure minimum stack size */
CallInfo *ci;
checkstackGCp(L, LUA_MINSTACK, func); /* ensure minimum stack size */
L->ci = ci = next_ci(L);
ci->nresults = nresults;
ci->callstatus = CIST_C;
ci->top = L->top + LUA_MINSTACK;
ci->func = func;
L->ci = ci;
lua_assert(ci->top <= L->stack_last);
if (L->hookmask & LUA_MASKCALL) {
int narg = cast_int(L->top - func) - 1;
@@ -485,12 +485,13 @@ void luaD_call (lua_State *L, StkId func, int nresults) {
break;
}
case LUA_VLCL: { /* Lua function */
CallInfo *ci = next_ci(L);
CallInfo *ci;
Proto *p = clLvalue(s2v(func))->p;
int narg = cast_int(L->top - func) - 1; /* number of real arguments */
int nfixparams = p->numparams;
int fsize = p->maxstacksize; /* frame size */
checkstackp(L, fsize, func);
checkstackGCp(L, fsize, func);
L->ci = ci = next_ci(L);
ci->nresults = nresults;
ci->u.l.savedpc = p->code; /* starting point */
ci->callstatus = 0;
@@ -504,7 +505,7 @@ void luaD_call (lua_State *L, StkId func, int nresults) {
break;
}
default: { /* not a function */
checkstackp(L, 1, func); /* space for metamethod */
checkstackGCp(L, 1, func); /* space for metamethod */
luaD_tryfuncTM(L, func); /* try to get '__call' metamethod */
goto retry; /* try again with metamethod */
}