Function test_then_block

src/Chain/libraries/glua/lparser.cpp:1439–1473

static void test_then_block(LexState *ls, int *escapelist) {
    /* test_then_block -> [IF | ELSEIF] cond THEN block */
    BlockCnt bl;
    FuncState *fs = ls->fs;
    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);
    if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) {
        luaK_goiffalse(ls->fs, &v);  /* will jump to label if condition is true */
        enterblock(fs, &bl, 0);  /* must enter block before 'goto' */
        gotostat(ls, v.t);  /* handle goto/break */
        skipnoopstat(ls);  /* skip other no-op statements */
        if (block_follow(ls, 0)) {  /* 'goto' is the entire block? */
            leaveblock(fs);
            return;  /* and that is it */
        }
        else  /* must skip over 'then' part if condition is false */
            jf = luaK_jump(fs);
    }
    else {  /* regular case (not goto/break) */
        luaK_goiftrue(ls->fs, &v);  /* skip over block if condition is false */
        enterblock(fs, &bl, 0);
        jf = v.f;
    }
    statlist(ls);  /* 'then' part */
    if (ls->L->force_stopping)
        return;
    leaveblock(fs);
    if (ls->t.token == TK_ELSE ||
        ls->t.token == TK_ELSEIF)  /* followed by 'else'/'elseif'? */
        luaK_concat(fs, escapelist, luaK_jump(fs));  /* must jump over it */
    luaK_patchtohere(fs, jf);
}


static void ifstat(LexState *ls, int line) {