/*
* substitute the argument list into the replacement string
* This would be simple except for ## and #
*/
void
substargs(Nlist* np, Tokenrow* rtr, Tokenrow** atr) {
Tokenrow tatr;
Token* tp;
int ntok, argno;
for (rtr->tp = rtr->bp; rtr->tp < rtr->lp;) {
if (rtr->tp->type == SHARP) { /* string operator */
tp = rtr->tp;
rtr->tp += 1;
if ((argno = lookuparg(np, rtr->tp)) < 0) {
error(ERROR, "# not followed by macro parameter");
continue;
}
ntok = 1 + (rtr->tp - tp);
rtr->tp = tp;
insertrow(rtr, ntok, stringify(atr[argno]));
continue;
}
if (rtr->tp->type == NAME
&& (argno = lookuparg(np, rtr->tp)) >= 0) {
if ((rtr->tp + 1)->type == DSHARP
|| (rtr->tp != rtr->bp && (rtr->tp - 1)->type == DSHARP))
insertrow(rtr, 1, atr[argno]);
else {
copytokenrow(&tatr, atr[argno]);
expandrow(&tatr, "<macro>");
insertrow(rtr, 1, &tatr);
dofree(tatr.bp);
}
continue;
}
rtr->tp++;
}
}
void process(Tokenrow *trp)
{
int anymacros = 0;
for (;;)
{
if (trp->tp >= trp->lp)
{
trp->tp = trp->lp = trp->bp;
outbufp = outbuf;
anymacros |= gettokens(trp, 1);
trp->tp = trp->bp;
}
if (trp->tp->type == END)
{
if (--incdepth >= 0)
{
if (cursource->ifdepth)
error(ERROR, "Unterminated conditional in #include");
unsetsource();
cursource->line += cursource->lineinc;
trp->tp = trp->lp;
genline();
continue;
}
if (ifdepth)
error(ERROR, "Unterminated #if/#ifdef/#ifndef");
break;
}
if (trp->tp->type == SHARP)
{
trp->tp += 1;
control(trp);
}
else if (!skipping && anymacros)
expandrow(trp, NULL);
if (skipping)
setempty(trp);
puttokens(trp);
anymacros = 0;
cursource->line += cursource->lineinc;
if (cursource->lineinc > 1)
{
genline();
}
}
}
/**
* process - 处理c源程序的总函数
* @trp: 用来存储c源程序中的一行Token
*/
void process(Tokenrow *trp) {
int anymacros = 0;
for (;;) {
if (trp->tp >= trp->lp) { /* 如果当前token row中没有有效数据 */
trp->tp = trp->lp = trp->bp; /* 重置token row的当前token指针 */
outp = outbuf; /* 重置输出缓冲区的当前指针 */
anymacros |= gettokens(trp, 1); /* 得到一行Token */
trp->tp = trp->bp;
}
if (trp->tp->type == END) { /* 如果遇到EOFC结束符 */
if (--incdepth >= 0) {
if (cursource->ifdepth)
error(ERROR,"Unterminated conditional in #include");
unsetsource();
cursource->line += cursource->lineinc;
trp->tp = trp->lp;
genline();
continue;
}
if (ifdepth)
error(ERROR, "Unterminated #if/#ifdef/#ifndef");
break;
}
if (trp->tp->type==SHARP) { /* 如果当前Token是'#'字符 */
trp->tp += 1; /* tp移动到token row中的下一个token */
control(trp); /* 处理预处理指令部分（宏定义，条件编译，头文件包含） */
} else if (!skipping && anymacros)
expandrow(trp, NULL);
if (skipping) /* 如果当前是忽略状态 */
setempty(trp); /* 置空当前行 */
puttokens(trp); /* 输出当前行 */
anymacros = 0;
cursource->line += cursource->lineinc;
if (cursource->lineinc>1) {
genline();
}
}
}
/* decode a run length encoded sgi image */
static void
decode_rle_sgi(SGIInfo *info, unsigned char *data, mp_image_t *mpi)
{
unsigned char *rle_data, *dest_row;
uint32_t *starttab;
int y, z, xsize, ysize, zsize, chan_offset;
long start_offset;
xsize = info->xsize;
ysize = info->ysize;
zsize = info->zsize;
/* rle offset table is right after the header */
starttab = (uint32_t*)(data + SGI_HEADER_LEN);
for (z = 0; z < zsize; z++) {
/* set chan_offset so RGB ends up BGR */
chan_offset = (zsize - 1) - z;
/* The origin for SGI images is the lower-left corner
so read scan lines from bottom to top */
for (y = ysize - 1; y >= 0; y--) {
dest_row = mpi->planes[0] + mpi->stride[0] * (ysize - 1 - y);
/* set start of next run (offsets are from start of header) */
start_offset = AV_RB32(&starttab[y + z * ysize]);
rle_data = &data[start_offset];
if(info->zsize == SGI_GRAYSCALE_IMAGE) {
expandrow_gs(dest_row, rle_data);
} else {
expandrow(dest_row, rle_data, chan_offset);
}
}
}
}
/*
* Evaluate an #if #elif #ifdef #ifndef line. trp->tp points to the keyword.
*/
long
eval(Tokenrow *trp, int kw)
{
Token *tp;
Nlist *np;
int ntok, rand;
trp->tp++;
if (kw==KIFDEF || kw==KIFNDEF) {
if (trp->lp - trp->bp != 4 || trp->tp->type!=NAME) {
error(ERROR, "Syntax error in #ifdef/#ifndef");
return 0;
}
np = lookup(trp->tp, 0);
return (kw==KIFDEF) == (np && np->flag&(ISDEFINED|ISMAC));
}
ntok = trp->tp - trp->bp;
kwdefined->val = KDEFINED; /* activate special meaning of defined */
expandrow(trp, "<if>");
kwdefined->val = NAME;
vp = vals;
op = ops;
*op++ = END;
for (rand=0, tp = trp->bp+ntok; tp < trp->lp; tp++) {
switch(tp->type) {
case WS:
case NL:
continue;
/* nilary */
case NAME:
case NAME1:
case NUMBER:
case CCON:
case STRING:
if (rand)
goto syntax;
if (vp == &vals[NSTAK]) {
error(ERROR, "Eval botch (stack overflow)");
return 0;
}
*vp++ = tokval(tp);
rand = 1;
continue;
/* unary */
case DEFINED:
case TILDE:
case NOT:
if (rand)
goto syntax;
*op++ = tp->type;
continue;
/* unary-binary */
case PLUS: case MINUS: case STAR: case AND:
if (rand==0) {
if (tp->type==MINUS)
*op++ = UMINUS;
if (tp->type==STAR || tp->type==AND) {
error(ERROR, "Illegal operator * or & in #if/#elsif");
return 0;
}
continue;
}
/* flow through */
/* plain binary */
case EQ: case NEQ: case LEQ: case GEQ: case LSH: case RSH:
case LAND: case LOR: case SLASH: case PCT:
case LT: case GT: case CIRC: case OR: case QUEST:
case COLON: case COMMA:
if (rand==0)
goto syntax;
if (evalop(priority[tp->type])!=0)
return 0;
*op++ = tp->type;
rand = 0;
continue;
case LP:
if (rand)
goto syntax;
*op++ = LP;
continue;
case RP:
if (!rand)
goto syntax;
if (evalop(priority[RP])!=0)
return 0;
if (op<=ops || op[-1]!=LP) {
goto syntax;
}
op--;
continue;
default:
error(ERROR,"Bad operator (%t) in #if/#elsif", tp);
return 0;
}
}
if (rand==0)
goto syntax;
if (evalop(priority[END])!=0)
return 0;
if (op!=&ops[1] || vp!=&vals[1]) {
error(ERROR, "Botch in #if/#elsif");
return 0;
}
if (vals[0].type==UND)
error(ERROR, "Undefined expression value");
return vals[0].val;
syntax:
error(ERROR, "Syntax error in #if/#elsif");
return 0;
}
void
control(Tokenrow *trp)
{
Nlist *np;
Token *tp;
tp = trp->tp;
if (tp->type!=NAME) {
if (tp->type==NUMBER)
goto kline;
if (tp->type != NL)
error(ERROR, "Unidentifiable control line");
return; /* else empty line */
}
if ((np = lookup(tp, 0))==NULL || (np->flag&ISKW)==0 && !skipping) {
error(WARNING, "Unknown preprocessor control %t", tp);
return;
}
if (skipping) {
if ((np->flag&ISKW)==0)
return;
switch (np->val) {
case KENDIF:
if (--ifdepth<skipping)
skipping = 0;
--cursource->ifdepth;
setempty(trp);
return;
case KIFDEF:
case KIFNDEF:
case KIF:
if (++ifdepth >= NIF)
error(FATAL, "#if too deeply nested");
++cursource->ifdepth;
return;
case KELIF:
case KELSE:
if (ifdepth<=skipping)
break;
return;
default:
return;
}
}
switch (np->val) {
case KDEFINE:
dodefine(trp);
break;
case KUNDEF:
tp += 1;
if (tp->type!=NAME || trp->lp - trp->bp != 4) {
error(ERROR, "Syntax error in #undef");
break;
}
if ((np = lookup(tp, 0)) != NULL)
np->flag &= ~ISDEFINED;
break;
case KPRAGMA:
return;
case KIFDEF:
case KIFNDEF:
case KIF:
if (++ifdepth >= NIF)
error(FATAL, "#if too deeply nested");
++cursource->ifdepth;
ifsatisfied[ifdepth] = 0;
if (eval(trp, np->val))
ifsatisfied[ifdepth] = 1;
else
skipping = ifdepth;
break;
case KELIF:
if (ifdepth==0) {
error(ERROR, "#elif with no #if");
return;
}
if (ifsatisfied[ifdepth]==2)
error(ERROR, "#elif after #else");
if (eval(trp, np->val)) {
if (ifsatisfied[ifdepth])
skipping = ifdepth;
else {
skipping = 0;
ifsatisfied[ifdepth] = 1;
}
} else
skipping = ifdepth;
break;
case KELSE:
if (ifdepth==0 || cursource->ifdepth==0) {
error(ERROR, "#else with no #if");
return;
}
if (ifsatisfied[ifdepth]==2)
error(ERROR, "#else after #else");
if (trp->lp - trp->bp != 3)
error(ERROR, "Syntax error in #else");
skipping = ifsatisfied[ifdepth]? ifdepth: 0;
ifsatisfied[ifdepth] = 2;
break;
case KENDIF:
if (ifdepth==0 || cursource->ifdepth==0) {
error(ERROR, "#endif with no #if");
return;
}
--ifdepth;
--cursource->ifdepth;
if (trp->lp - trp->bp != 3)
error(WARNING, "Syntax error in #endif");
break;
case KERROR:
trp->tp = tp+1;
error(WARNING, "#error directive: %r", trp);
break;
case KLINE:
trp->tp = tp+1;
expandrow(trp, "<line>");
tp = trp->bp+2;
kline:
if (tp+1>=trp->lp || tp->type!=NUMBER || tp+3<trp->lp
|| (tp+3==trp->lp && ((tp+1)->type!=STRING)||*(tp+1)->t=='L')){
error(ERROR, "Syntax error in #line");
return;
}
cursource->line = atol((char*)tp->t)-1;
if (cursource->line<0 || cursource->line>=32768)
error(WARNING, "#line specifies number out of range");
tp = tp+1;
if (tp+1<trp->lp)
cursource->filename=(char*)newstring(tp->t+1,tp->len-2,0);
return;
case KDEFINED:
error(ERROR, "Bad syntax for control line");
break;
case KINCLUDE:
doinclude(trp);
trp->lp = trp->bp;
return;
case KEVAL:
eval(trp, np->val);
break;
default:
error(ERROR, "Preprocessor control `%t' not yet implemented", tp);
break;
}
setempty(trp);
return;
}
void
doinclude(Tokenrow* trp) {
char fname[256], iname[256];
Includelist* ip;
int angled, len, fd, i;
trp->tp += 1;
if (trp->tp >= trp->lp)
goto syntax;
if (trp->tp->type != STRING && trp->tp->type != LT) {
len = trp->tp - trp->bp;
expandrow(trp, "<include>");
trp->tp = trp->bp + len;
}
if (trp->tp->type == STRING) {
len = trp->tp->len - 2;
if (len > sizeof(fname) - 1)
len = sizeof(fname) - 1;
strncpy(fname, (char*)trp->tp->t + 1, len);
angled = 0;
} else if (trp->tp->type == LT) {
len = 0;
trp->tp++;
while (trp->tp->type != GT) {
if (trp->tp > trp->lp || len + trp->tp->len + 2 >= sizeof(fname))
goto syntax;
strncpy(fname + len, (char*)trp->tp->t, trp->tp->len);
len += trp->tp->len;
trp->tp++;
}
angled = 1;
} else
goto syntax;
trp->tp += 2;
if (trp->tp < trp->lp || len == 0)
goto syntax;
fname[len] = '\0';
appendDirToIncludeList(basepath(fname));
if (fname[0] == '/') {
fd = open(fname, 0);
strcpy(iname, fname);
} else for (fd = -1, i = NINCLUDE - 1; i >= 0; i--) {
ip = &includelist[i];
if (ip->file == NULL || ip->deleted || (angled && ip->always == 0))
continue;
if (strlen(fname) + strlen(ip->file) + 2 > sizeof(iname))
continue;
strcpy(iname, ip->file);
strcat(iname, "/");
strcat(iname, fname);
if ((fd = open(iname, 0)) >= 0)
break;
}
if (Mflag > 1 || (!angled && Mflag == 1)) {
write(1, objname, strlen(objname));
write(1, iname, strlen(iname));
write(1, "\n", 1);
}
if (fd >= 0) {
if (++incdepth > 10)
error(FATAL, "#include too deeply nested");
setsource((char*)newstring((uchar*)iname, strlen(iname), 0), fd, NULL);
genline();
} else {
trp->tp = trp->bp + 2;
error(ERROR, "Could not find include file %r", trp);
}
return;
syntax:
error(ERROR, "Syntax error in #include");
return;
}
/**
* control - 处理预处理控制指令（头文件包含指令，行控制指令，条件编译指令）
* @trp: 一行源程序的Token
* 返回值：无
*/
void control(Tokenrow *trp) {
Nlist *np;
Token *tp;
tp = trp->tp; /* 获得Tokenrow中的当前Token(指向预处理控制指令关键字) */
if (tp->type!=NAME) { /* 如果当前Token不是标识符 */
if (tp->type==NUMBER) /* 如果当前Token是数字 */
goto kline; /* 跳转，处理行控制指令 */
if (tp->type != NL) /* 如果该Token既不是标识符，也不是数字 */
error(ERROR, "Unidentifiable control line"); /* 则，打印信息`无法识别的控制指令行' */
return; /* 该行处理完毕，函数返回（该行为空行，无控制信息，else empty line) */
}
/* 如果当前Token是标识符但标识符不在标识符hash表中 或 标识符在hash表中但不是关键字且不能略过（TODO：啥是略过？） */
if ((np = lookup(tp, 0))==NULL || (np->flag&ISKW)==0 && !skipping) {
error(WARNING, "Unknown preprocessor control %t", tp); /* 打印信息，无法识别的预处理控制指令 */
return; /* 该行处理完毕 */
}
if (skipping) { /* TODO: 啥是skipping? */
if ((np->flag&ISKW)==0) /* 如果np不是关键字 */
return; /* 函数返回 */
switch (np->val) {
case KENDIF:
if (--ifdepth<skipping)
skipping = 0;
--cursource->ifdepth;
setempty(trp);
return;
case KIFDEF:
case KIFNDEF:
case KIF:
if (++ifdepth >= NIF)
error(FATAL, "#if too deeply nested");
++cursource->ifdepth;
return;
case KELIF:
case KELSE:
if (ifdepth<=skipping)
break;
return;
default:
return;
}
}
switch (np->val) {
case KDEFINE: /* #define，定义宏 */
dodefine(trp); /* 定义宏 */
break;
case KUNDEF: /* #undef */
tp += 1; /* tp指向宏名 */
if (tp->type!=NAME || trp->lp - trp->bp != 4) { /* 如果tp不是标识符类型 或者 lp-bp!=4 (lp和bp之间有4个Token) */
error(ERROR, "Syntax error in #undef"); /* 打印错误信息 */
break;
}
if ((np = lookup(tp, 0)) != NULL) /* 如果在hash表中找到了tp所指向的宏名 */
np->flag &= ~ISDEFINED; /* 清零ISDEFINED标志位 */
break;
case KPRAGMA: /* #pragma */
return;
case KIFDEF: /* #ifdef */
case KIFNDEF: /* #ifndef */
case KIF: /* #if */
if (++ifdepth >= NIF) /* 全局条件编译语句的嵌套深度值加1 */
error(FATAL, "#if too deeply nested"); /* 如果嵌套深度值大于NIF，则打印错误信息 `#if中嵌入太深' */
++cursource->ifdepth; /* 当前输入源的条件编译语句的嵌套深度值加1 */
ifsatisfied[ifdepth] = 0; /* 设定条件编译语句的嵌套深度值对应的if语句还未被满足 */
if (eval(trp, np->val))
ifsatisfied[ifdepth] = 1;
else
skipping = ifdepth;
break;
case KELIF: /* #elif */
if (ifdepth==0) {
error(ERROR, "#elif with no #if");
return;
}
if (ifsatisfied[ifdepth]==2)
error(ERROR, "#elif after #else");
if (eval(trp, np->val)) {
if (ifsatisfied[ifdepth])
skipping = ifdepth;
else {
skipping = 0;
ifsatisfied[ifdepth] = 1;
}
} else
skipping = ifdepth;
break;
case KELSE: /* #else */
if (ifdepth==0 || cursource->ifdepth==0) {
error(ERROR, "#else with no #if");
return;
}
if (ifsatisfied[ifdepth]==2)
error(ERROR, "#else after #else");
if (trp->lp - trp->bp != 3)
error(ERROR, "Syntax error in #else");
skipping = ifsatisfied[ifdepth]? ifdepth: 0;
ifsatisfied[ifdepth] = 2;
break;
case KENDIF: /* #endif */
if (ifdepth==0 || cursource->ifdepth==0) {
error(ERROR, "#endif with no #if");
return;
}
--ifdepth;
--cursource->ifdepth;
if (trp->lp - trp->bp != 3)
error(WARNING, "Syntax error in #endif");
break;
case KERROR: /* #error */
trp->tp = tp+1;
error(WARNING, "#error directive: %r", trp);
break;
case KLINE: /* #line */
trp->tp = tp+1;
expandrow(trp, "<line>");
tp = trp->bp+2;
kline: /* 行控制信息处理（line control）*/
if (tp+1>=trp->lp || tp->type!=NUMBER || tp+3<trp->lp
|| (tp+3==trp->lp && ((tp+1)->type!=STRING)||*(tp+1)->t=='L')) { /* 如果行控制语法有误 */
/* 上面的if判断中共有5种语法错误检查:
* 1. 如果只有`# 123\n'
* 2. 如果当前token不是数字类型
* 3. 如果有类似`# 123 "file.c" 2 3'的行，那么这种行不被lcc的预处理程序支持。TODO:lcc不支持行控制中的flag语法.
* 4. 如果在`# linenum filename'中，filename不是字符串
* 5. 如果filename是宽字符字符串
*/
error(ERROR, "Syntax error in #line"); /* 打印错误信息 */
return; /* 该函数返回 */
}
cursource->line = atol((char*)tp->t)-1; /* 更新当前输入源的行号信息 */
if (cursource->line<0 || cursource->line>=32768) /* 如果转化后的行号小于0或者行号大于32768 */
error(WARNING, "#line specifies number out of range"); /* 打印错误信息 */
tp = tp+1; /* 指针移动到filename位置 */
if (tp+1<trp->lp) /* 如果filename存在（因为filename后通常紧跟一个换行符token） */
cursource->filename=(char*)newstring(tp->t+1,tp->len-2,0); /* 保存输入源的文件名 */
return; /* 该行处理完毕，函数返回 */
case KDEFINED: /* #defined */
error(ERROR, "Bad syntax for control line"); /* 打印语法错误提示 */
break;
case KINCLUDE: /* #include */
doinclude(trp);
trp->lp = trp->bp;
return;
case KEVAL: /* #eval */
eval(trp, np->val);
break;
default: /* # other */
error(ERROR, "Preprocessor control `%t' not yet implemented", tp); /* 未实现的预处理控制指令 */
break;
}
setempty(trp); /* 置空Tokenrow */
return;
}
