commit deb807837c1ed327d6069fb6676e624784d01e22
parent 26eb144541714343f8aeb124150d60cf7d91fac7
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 25 Apr 2018 13:25:53 -0300
'luaO_pushvfstring' does not need to reallocate stack
(less error cases in the API)
Diffstat:
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/lobject.c b/lobject.c
@@ -1,5 +1,5 @@
/*
-** $Id: lobject.c,v 2.123 2018/01/28 15:13:26 roberto Exp roberto $
+** $Id: lobject.c,v 2.124 2018/02/27 18:47:32 roberto Exp roberto $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/
@@ -393,7 +393,7 @@ void luaO_tostring (lua_State *L, TValue *obj) {
static void pushstr (lua_State *L, const char *str, size_t l) {
setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
- luaD_inctop(L);
+ L->top++;
}
@@ -402,11 +402,10 @@ static void pushstr (lua_State *L, const char *str, size_t l) {
conventional formats, plus Lua-specific '%I' and '%U'
*/
const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
- int n = 0;
- for (;;) {
- const char *e = strchr(fmt, '%');
- if (e == NULL) break;
- pushstr(L, fmt, e - fmt);
+ int n = 0; /* number of strings in the stack to concatenate */
+ const char *e; /* points to next conversion specifier */
+ while ((e = strchr(fmt, '%')) != NULL) {
+ pushstr(L, fmt, e - fmt); /* string up to conversion specifier */
switch (*(e+1)) {
case 's': { /* zero-terminated string */
const char *s = va_arg(argp, char *);
@@ -433,7 +432,7 @@ const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
case 'f': { /* a 'lua_Number' */
setfltvalue(s2v(L->top), cast_num(va_arg(argp, l_uacNumber)));
top2str: /* convert the top element to a string */
- luaD_inctop(L);
+ L->top++;
luaO_tostring(L, s2v(L->top - 1));
break;
}
@@ -460,9 +459,12 @@ const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
}
}
n += 2;
- fmt = e+2;
+ if (L->top + 2 > L->stack_last) { /* no free stack space? */
+ luaV_concat(L, n);
+ n = 1;
+ }
+ fmt = e + 2;
}
- luaD_checkstack(L, 1);
pushstr(L, fmt, strlen(fmt));
if (n > 0) luaV_concat(L, n + 1);
return svalue(s2v(L->top - 1));