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/*
* Expand MMacro-local things: parameter references (%0, %n, %+n,
* %-n) and MMacro-local identifiers (%%foo).
*/
static Token *expand_mmac_params(Token * tline)
...{
Token *t, *tt, **tail, *thead;
/**//* thead 是链表头，tail 指向链表尾部 */
tail = &thead;
thead = NULL;
/**//* 如果是可以扩展的宏参数，则扩展，或则照旧 */
while (tline)
...{
if (tline->type == TOK_PREPROC_ID &&
(((tline->text[1] == '+' || tline->text[1] == '-') /**//* %+- num/space */
&& tline->text[2]) || tline->text[1] == '%' /**//* %% */
|| (tline->text[1] >= '0' && tline->text[1] <= '9'))) /**//* %num */
...{
char *text = NULL;
int type = 0, cc; /**//* type = 0 to placate optimisers */
char tmpbuf[30];
int n, i;
MMacro *mac;
t = tline;
tline = tline->next;
mac = istk->mstk;
while (mac && !mac->name) /**//* avoid mistaking %reps for macros */
mac = mac->next_active;
if (!mac)
error(ERR_NONFATAL, "`%s': not in a macro call", t->text);
else
...{
switch (t->text[1])
...{
/**//*
* We have to make a substitution of one of the
* forms %1, %-1, %+1, %%foo, %0.
*/
case '0': /**//* 有几个参数 */
type = TOK_NUMBER;
snprintf(tmpbuf, sizeof(tmpbuf), "%d", mac->nparam);
text = nasm_strdup(tmpbuf);
break;
case '%': /**//* 假设变量名是Local, 则结果是..@XLoacal, 其中X是mac->unique
* 通过修改变量名来是他成为唯一的变量, C/C++也是这样子
*/
type = TOK_ID;
snprintf(tmpbuf, sizeof(tmpbuf), "..@%lu.", mac->unique);
text = nasm_strcat(tmpbuf, t->text + 2);
break;
case '-': /**//* 处理条件宏定义 */
n = atoi(t->text + 2) - 1; /**//* %-num */
if (n >= mac->nparam) /**//* 验证要求的参数是否超出提供的范围 */
tt = NULL;
else ...{
if (mac->nparam > 1)
n = (n + mac->rotate) % mac->nparam; /**//* %rotate宏定义 */
tt = mac->params[n]; /**//* 取出第几个参数，从0开始计数 */
}
cc = find_cc(tt);
if (cc == -1) ...{
error(ERR_NONFATAL, "macro parameter %d is not a condition code", n + 1);
text = NULL;
} else ...{
type = TOK_ID;
if (inverse_ccs[cc] == -1) ...{
error(ERR_NONFATAL, "condition code `%s' is not invertible", conditions[cc]);
text = NULL;
} else
text = nasm_strdup(conditions[inverse_ccs[cc]]);
}
break;
case '+': /**//* 处理条件宏定义 */
n = atoi(t->text + 2) - 1;
if (n >= mac->nparam)
tt = NULL;
else ...{
if (mac->nparam > 1)
n = (n + mac->rotate) % mac->nparam;
tt = mac->params[n];
}
cc = find_cc(tt);
if (cc == -1) ...{
error(ERR_NONFATAL, "macro parameter %d is not a condition code", n + 1);
text = NULL;
} else ...{
type = TOK_ID;
text = nasm_strdup(conditions[cc]);
}
break;
default:
n = atoi(t->text + 1) - 1;
if (n >= mac->nparam)
tt = NULL;
else ...{
if (mac->nparam > 1)
n = (n + mac->rotate) % mac->nparam;
tt = mac->params[n];
}
if (tt) ...{ /**//* 复制参数 */
for (i = 0; i < mac->paramlen[n]; i++) ...{
*tail = new_Token(NULL, tt->type, tt->text, 0);
tail = &(*tail)->next;
tt = tt->next;
}
}
text = NULL; /**//* we've done it here */
break;
}
}
if (!text)
...{
delete_Token(t);
}
else
...{
*tail = t;
tail = &t->next;
t->type = type;
nasm_free(t->text);
t->text = text;
t->mac = NULL;
}
continue;
}
else
...{
t = *tail = tline;
tline = tline->next;
t->mac = NULL;
tail = &t->next;
}
}
*tail = NULL;
t = thead;
for (; t && (tt = t->next) != NULL; t = t->next)
...{
switch (t->type)
...{
case TOK_WHITESPACE:
if (tt->type == TOK_WHITESPACE) ...{ /**//* 删除空格Token */
t->next = delete_Token(tt);
}
break;
case TOK_ID:
if (tt->type == TOK_ID || tt->type == TOK_NUMBER) ...{
char *tmp = nasm_strcat(t->text, tt->text);
nasm_free(t->text);
t->text = tmp;
t->next = delete_Token(tt);
}
break;
case TOK_NUMBER:
if (tt->type == TOK_NUMBER) ...{
char *tmp = nasm_strcat(t->text, tt->text);
nasm_free(t->text);
t->text = tmp;
t->next = delete_Token(tt);
}
break;
}
}
return thead;
}
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