preproc.c

花了很长时间找了这么多c语言的编译器

        --global_flag;
        return incldepth == 0;
}
/*
 * Undefine
 */
int doundef(void)
{
	getsym();
	if (!ifskip)
		undef2();
	return(incldepth == 0);
}
int undef2(void)
{
	if (lastst != id) 
    generror(ERR_IDEXPECT,0,0);
	else {
		SYM **p = (SYM **)LookupHash(unmangid,defhash,HASHTABLESIZE);
		if (p) {
			*p = (*p)->next;
		}
	}
}
void getdefsym(void)
{
				if (backupchar != -1) {
					lastst = backupchar;
					backupchar = -1;
					return;
				}
restart:        /* we come back here after comments */
        while(iswhitespacechar(lastch))
                getch();
        if( lastch == -1)
                lastst = eof;
        else if(isdigit(lastch))
                getnum();
        else if(isstartchar(lastch)) {
								lptr--;
                defid(unmangid,&lptr,0);	
								lastch = *lptr++;
								lastst = id;
				}
        else if (getsym2())
					goto restart;
}
int defid(short *name, short **p, char *q)
/*
 * Get an identifier during macro replacement
 */
{
	int count = 0,i=0;
			while (issymchar(**p)) {
				if (count < 100) {
					name[count++] = *(*p);
					if (q)
						i+=installphichar(*(*p),q,i);
				}
				(*p)++;
			}
			if (q) {
				if ((q[i-1] & 0xf0) == 0x90)
					q[i-1] = 0x90;
    	  q[i] = '\0';
			}
	name[count] = 0;
	return(count);
}
/* 
 * Insert a replacement string
 */
int definsert(short *end, short *begin, short * text, int len, int replen)
{
	short *q;
	int i,p, r;
	int val;
	if (begin != inputline) 
		if (*(begin-1) == '#') {
			if (*(begin-2) != '#') {
				begin--;
				replen++;
				r = pstrlen(text);
			
				text[r++] = '\"';
				text[r] = 0;
				for (i=r; i >= 0; i--)
					text[i+1] = text[i];
				*text = '\"';
			}
		}
	p = pstrlen(text);
	val = p - replen;
	r = pstrlen(begin);
	if (val + strlen(begin) >= len-1) {
		generror(ERR_MACROSUBS,0,0);
		return(-8000);
	}
	if (val > 0)
		for (q = begin + r+1; q >= end; q--)
			*(q+val) = *q;
	else
		if (val < 0) {
			r = pstrlen(end)+1;
			for (q = end; q < end+r; q++ )
				*(q+val) = *q;
		}
	for (i=0; i < p; i++)
		begin[i] = text[i]; 
	return(val);
}
/* replace macro args */	
int defreplace(short *macro, int count, short **oldargs, short **newargs)
{
	int i,rv;
	int instring = 0;
	short narg[1024];
	short name[100];
	short *p=macro,*q;
	while (*p) {
		if (*p == instring)
			instring = 0;
		else if (*p == '\'' || *p == '"')
			instring = *p;
		else if (!instring && isstartchar(*p)) {
			q = p;
			defid(name,&p,0);
			for (i=0; i < count; i++)
				if (!pstrcmp(name,oldargs[i])) {
					pstrcpy(narg,newargs[i]);
					if ((rv = definsert(p,q,narg,1024-(q-macro),p-q)) == -8000)
						return(FALSE);
					else {
						p += rv;
						break;
					}
				}
		}
		p++;
	}
	return(TRUE);
}
/* Handlers for default macros */
void cnvt(short *out,char *in)
{
	while (*in) 
		*out++=*in++;
	*out = 0;
}
void filemac(short *string)
{
	char str1[40];
	sprintf(str1,"\"%s\"",infile);
	cnvt(string,str1);
}
void datemac(short *string)
{
	char str1[40];
	struct tm *t1;
	time_t t2;
	time(&t2);
	t1 = localtime(&t2);
 	strftime(str1,40,"\"%b %d %Y\"",t1);
	cnvt(string,str1);
}
void timemac(short *string)
{
	char str1[40];
	struct tm *t1;
	time_t t2;
	time(&t2);
	t1 = localtime(&t2);
	str1[0] = '"';
 	strftime(str1,40,"\"%X\"",t1);
	cnvt(string,str1);
}
void linemac(short *string)
{
	char str1[40];
	sprintf(str1,"%d",lineno);
	cnvt(string,str1);
}
/* Scan for default macros and replace them */
void defmacroreplace(short *macro, short *name)
{
	int i;
	macro[0] = 0;
	for (i=0; i < INGROWNMACROS; i++)
		if (!strcmp(name,ingrownmacros[i].s)) {
			(ingrownmacros[i].func)(macro);
			break;
		}
}
/* Scan line for macros and do replacements */
void defcheck(short *line)
{
	short macro[1024];
	short name[100];
	short *args[40];
	char ascii[60];
	int tryagain = TRUE, changed = FALSE, waiting = FALSE,rv;
	short *p = line,*q;
	SYM *sp;
	while (tryagain) {
		p = line;
		tryagain = FALSE;
		while(*p) {
			q = p;
			if (*p == '"') {
				waiting = !waiting;
				p++;
			}
			else if (waiting)
				p++;
			else if (isstartchar(*p)) {
				defid(name,&p,ascii);
				if ((sp = search(ascii,&defsyms)) != 0) {
					DEFSTRUCT *def = sp->value.s;
					pstrcpy(macro,def->string);
					if (def->argcount) {
						int count = 0;
						short *q = p;
							while (iswhitespacechar(*q))
								q++;
						if (*q++ != '(')
							goto join;
						p = q;
						if (def->argcount > 1) {
							do {
								short *nm = name;
								int nestedparen = 0;
								while (((*p != ',' && *p != ')') || nestedparen) && *p != '\n') {
										if (*p == '(')
											nestedparen++;
										if (*p == ')' && nestedparen)
											nestedparen--;
										*nm++ = *p++;
								}
								while (iswhitespacechar(*(nm-1)))
									nm--;
								*nm = 0;
								nm = name;
								while (iswhitespacechar(*nm))
									nm++;
								args[count++] = plitlate(nm);
							} while (*p++ == ',');
						}
						else while (iswhitespacechar(*p++));
						if (*(p-1) != ')' || count != def->argcount-1) {
							generror(ERR_MACROSUBS,0,0);
							return;
						}
						/* Can't replace if tokenizing next */
						if (*p == '#' && *(p+1) == '#')
							continue;
						if (count == 0)
							goto insert;
						if (!defreplace(macro,count,def->args,args))
							return;
					}
insert:
					if ((rv=definsert(p,q,macro,4096-(q-line),p-q))==-8000)
						return;
					p+=rv;
					changed = tryagain = TRUE;
				}
				else {
join:
					defmacroreplace(macro,ascii);
					if (macro[0]) {
						if ((rv=definsert(p,q,macro,4096-(q-line),p-q))==-8000)
							return;
						p += rv;
						changed = TRUE;
					}
				}
			}
			else p++;
		}
	}
	/* Token pasting */
	if (changed) {
		p = q = line;
		while (*p) {
			if (*p == '#' && *(p+1) == '#')
				p+=2;
			else
				*q++ = *p++;
		}
		*q = 0;
	}
}
static void repdefines(short *lptr)
/*
 * replace 'defined' keyword in #IF and #ELIF statements
 */
{
	short *q = lptr;
	short name[40];
	char ascii[60];
	while (*lptr) {
		if (!pstrncmp(lptr,defkw,7)) {
			lptr +=7;
			if (*lptr == '(') 
				lptr++;
			else 
		 		expecttoken(openpa,0);
      while(iswhitespacechar(*lptr))
              lptr++;
			defid(name,&lptr,ascii);
      while(iswhitespacechar(*lptr))
              lptr++;
			if (*lptr == ')')
				lptr++;
			else
				expecttoken(closepa,0);
			if (search(ascii,&defsyms) != 0)
				*q++ = '1';
			else
				*q++ = '0';
			*q++ = ' ';
				
		}
		else {
			*q++ = *lptr++;
		}
	}
  *q = 0;
}
void pushif(void)
/* Push an if context */
{
	IFSTRUCT *p;
	global_flag++;
	p = xalloc(sizeof(IFSTRUCT));
	global_flag--;
	p->link = ifs;
	p->iflevel = ifskip;
	p->elsetaken = elsetaken;
	elsetaken = FALSE;
	ifs = p;
}
void popif(void)
/* Pop an if context */
{
	if (ifs) {
		ifskip = ifs->iflevel;
		elsetaken = ifs->elsetaken;
		ifs = ifs->link;
	}
	else {
		ifskip = 0;
		elsetaken = 0;
	}
}	
void ansieol(void)
{
	if (prm_ansi) {
		while (iswhitespacechar(*lptr))
			lptr++;
		if (*lptr) {
			lastch = *lptr;
			lastst = kw_if;
			generror(ERR_UNEXPECT,0,0);
		}
	}
}
int doifdef (int flag)
/* Handle IFDEF */
{
	SYM *sp;
	getch();
	while(isspace(lastch))
		getch();
	if (!isstartchar(lastch)) {
    generror(ERR_IDEXPECT,0,0);
    return incldepth == 0;
	}
	else
		getid();
 	sp = search(unmangid,&defsyms);
  pushif();
	if (sp && !flag || !sp && flag)
		ifskip = TRUE;
	ansieol();
	return(incldepth == 0);
}
int doif(int flag)
/* Handle #if */
{
	getsym();
  pushif();
	cantnewline = TRUE;
	if (!intexpr(0))
		ifskip = TRUE;
	cantnewline = FALSE;
	ansieol();
	return(incldepth == 0);
}
int doelif(void)
/* Handle #elif */
{
	int is;
	getsym();
	cantnewline = TRUE;
	is = !intexpr(0);
	cantnewline = FALSE;
	if (ifs) {
		if (!ifs->iflevel)
			ifskip = !ifskip || is || elsetaken;
			if (!ifskip)
				elsetaken = TRUE;
	}
	else
		generror(ERR_PREPROCMATCH,0,0);
	ansieol();
	return(incldepth == 0);
}
/* handle else */
int doelse(void)
{
	if (ifs) {
		if (!ifs->iflevel)
			ifskip = !ifskip || elsetaken;
	}
	else
		generror(ERR_PREPROCMATCH,0,0);
	ansieol();
	return(incldepth == 0);
}
/* HAndle endif */
int doendif(void)
{
	if (!ifs)
		generror(ERR_PREPROCMATCH,0,0);
	popif();
	ansieol();
	return(incldepth == 0);
}