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update lua 5.4.2

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Cloud Wu
2020-11-16 10:51:36 +08:00
parent c7dc8751c7
commit 9eb37198ea
8 changed files with 64 additions and 77 deletions
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50
3rd/lua/lparser.c
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@@ -1623,59 +1623,21 @@ static void forstat (LexState *ls, int line) {
}
/*
** Check whether next instruction is a single jump (a 'break', a 'goto'
** to a forward label, or a 'goto' to a backward label with no variable
** to close). If so, set the name of the 'label' it is jumping to
** ("break" for a 'break') or to where it is jumping to ('target') and
** return true. If not a single jump, leave input unchanged, to be
** handled as a regular statement.
*/
static int issinglejump (LexState *ls, TString **label, int *target) {
if (testnext(ls, TK_BREAK)) { /* a break? */
*label = luaS_newliteral(ls->L, "break");
return 1;
}
else if (ls->t.token != TK_GOTO || luaX_lookahead(ls) != TK_NAME)
return 0; /* not a valid goto */
else {
TString *lname = ls->lookahead.seminfo.ts; /* label's id */
Labeldesc *lb = findlabel(ls, lname);
if (lb) { /* a backward jump? */
/* does it need to close variables? */
if (luaY_nvarstack(ls->fs) > stacklevel(ls->fs, lb->nactvar))
return 0; /* not a single jump; cannot optimize */
*target = lb->pc;
}
else /* jump forward */
*label = lname;
luaX_next(ls); /* skip goto */
luaX_next(ls); /* skip name */
return 1;
}
}
static void test_then_block (LexState *ls, int *escapelist) {
/* test_then_block -> [IF | ELSEIF] cond THEN block */
BlockCnt bl;
int line;
FuncState *fs = ls->fs;
TString *jlb = NULL;
int target = NO_JUMP;
expdesc v;
int jf; /* instruction to skip 'then' code (if condition is false) */
luaX_next(ls); /* skip IF or ELSEIF */
expr(ls, &v); /* read condition */
checknext(ls, TK_THEN);
line = ls->linenumber;
if (issinglejump(ls, &jlb, &target)) { /* 'if x then goto' ? */
luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */
if (ls->t.token == TK_BREAK) { /* 'if x then break' ? */
int line = ls->linenumber;
luaK_goiffalse(ls->fs, &v); /* will jump if condition is true */
luaX_next(ls); /* skip 'break' */
enterblock(fs, &bl, 0); /* must enter block before 'goto' */
if (jlb != NULL) /* forward jump? */
newgotoentry(ls, jlb, line, v.t); /* will be resolved later */
else /* backward jump */
luaK_patchlist(fs, v.t, target); /* jump directly to 'target' */
newgotoentry(ls, luaS_newliteral(ls->L, "break"), line, v.t);
while (testnext(ls, ';')) {} /* skip semicolons */
if (block_follow(ls, 0)) { /* jump is the entire block? */
leaveblock(fs);
@@ -1684,7 +1646,7 @@ static void test_then_block (LexState *ls, int *escapelist) {
else /* must skip over 'then' part if condition is false */
jf = luaK_jump(fs);
}
else { /* regular case (not a jump) */
else { /* regular case (not a break) */
luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */
enterblock(fs, &bl, 0);
jf = v.f;