/*
 * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
 * See the copyright notice in the ACK home directory, in the file "Copyright".
 */
/* $Header$ */
/* PREPROCESSOR DRIVER */

#include	<system.h>
#include	<alloc.h>
#include	"input.h"
#include	"obufsize.h"
#include	"arith.h"
#include	"LLlex.h"
#include	"class.h"
#include	"macro.h"
#include	"idf.h"
#include	"idfsize.h"
#include	"bits.h"
#include	"ln_prefix.h"
#include	"textsize.h"

char	_obuf[OBUFSIZE];
#ifdef DOBITS
char	bits[128];
#endif
extern int InputLevel;

Xflush()
{
	sys_write(STDOUT, _obuf, OBUFSIZE);
}

static char *SkipComment();
extern char options[];

/* #pragma directives are saved here and passed to the compiler later on.
 */
struct prag_info {
	int	pr_linnr;
	char	*pr_fil;
	char	*pr_text;
};
static struct prag_info *pragma_tab;
static int pragma_nr;

do_pragma()
{
	register int size = ITEXTSIZE;
	char *cur_line = Malloc(size);
	register char *c_ptr = cur_line;
	register int c = GetChar();

	*c_ptr = '\0';
	while(c != '\n') {
		if (c_ptr + 1 - cur_line == size) {
			cur_line = Realloc(cur_line, size += ITEXTSIZE);
			c_ptr = cur_line + size - 1;
		}
		*c_ptr++ = c;
		c = GetChar();
	}
	*c_ptr = '\0';
	if (!pragma_nr) {
		pragma_tab = (struct prag_info *)Malloc(sizeof(struct prag_info));
	} else {
		pragma_tab = (struct prag_info *)Realloc(pragma_tab
				    , sizeof(struct prag_info) * (pragma_nr+1));
	}
	pragma_tab[pragma_nr].pr_linnr = LineNumber;
	pragma_tab[pragma_nr].pr_fil = FileName;
	pragma_tab[pragma_nr].pr_text = cur_line;
	pragma_nr++;
	LineNumber++;
}

preprocess(fn)
	char *fn;
{
	register int c;
	register char *op = _obuf;
	register char *ob = &_obuf[OBUFSIZE];
	char Xbuf[256];
	int lineno = 0;
	int startline;

#define flush(X)	(sys_write(STDOUT,_obuf,X))
#define echo(ch) 	if (op == ob) { Xflush(); op = _obuf; } *op++ = (ch);
#define newline()	echo('\n')

	if (!options['P']) {
		/* Generate a line directive communicating the
		   source filename
		*/
		register char *p = Xbuf;

		sprint(p, "%s 1 \"%s\"\n",
			LINE_PREFIX,
			FileName);
		while (*p) {
			echo(*p++);
		}
	}

#define	do_line_dir(lineno, fn)						\
		if (lineno != LineNumber || fn != FileName) {		\
			fn = FileName;					\
			lineno = LineNumber;				\
			if (! options['P']) {				\
				register char *p = Xbuf;		\
									\
				sprint(p, "%s %d \"%s\"\n",		\
					LINE_PREFIX,			\
					LineNumber,			\
					FileName);			\
				while (*p) {				\
					echo(*p++);			\
				}					\
			}						\
		}

	for (;;) {
		LineNumber++;
		lineno++;
		startline = 1;
		c = GetChar();
		while (startline) {
		    /* first flush the saved pragma's */
		    if (pragma_nr) {
			register int i = 0;
			int LiNo = LineNumber;
			char *FiNam = FileName;

			while (i < pragma_nr) {
			    register char *c_ptr = "#pragma";

			    LineNumber = pragma_tab[i].pr_linnr;
			    FileName = pragma_tab[i].pr_fil;
			    do_line_dir(lineno, fn);
			    while (*c_ptr) { echo(*c_ptr++); }
			    c_ptr = pragma_tab[i].pr_text;
			    while (*c_ptr) { echo(*c_ptr++); }
			    newline(); lineno++;
			    free(pragma_tab[i].pr_text);
			    i++;
			}
			free(pragma_tab);
			pragma_tab = (struct prag_info *)0;
			pragma_nr = 0;
			LineNumber = LiNo;
			FileName = FiNam;
			do_line_dir(lineno, fn);
		    }


		    while (class(c) == STSKIP || c == '/') {
			if (c == '/') {
			    if (!InputLevel) {
				c = GetChar();
				if (c == '*') {
				    op = SkipComment(op, &lineno);
				    if (!op) return;
				    if (!options['C']) echo(' ');
				    c = GetChar();
				    continue;
				}
				UnGetChar();
				c = '/';
			    }
			    break;
			}
			echo(c);
			c = GetChar();
		    }

		    if (c == '#') {
			domacro();
			lineno++;
			newline();
			c = GetChar();
		    } else startline = 0;
		}
		do_line_dir(lineno, fn);
		for (;;) {

			/* illegal character */
			if (c & 0200)  {
				if (c == EOI) {
					newline();
					flush(op-_obuf);
					return;
				}
				fatal("non-ascii character read");
			}

			/* comments */
			if (c == '/' && !InputLevel) {
				c = GetChar();
				if (c == '*') {
					op = SkipComment(op, &lineno);
					if (!op) return;
					if (!options['C']) echo(' ');
					c = GetChar();
					continue;
				}
				echo('/');
				continue;
			}

			/* switch on character */
			switch(class(c)) {
			case STNL:
				echo(c);
				break;
			case STSTR:
			case STCHAR:
				{
				register int stopc = c;
				int escaped;

				do {

					escaped = 0;
					echo(c);
					c = GetChar();
					if (c == '\n') {
						break;
					}
					else if (c == EOI) {
						newline();
						flush(op-_obuf);
						return;
					}
					if (c == '\\') {
						echo(c);
						c = GetChar();
						if (c == '\n') {
							++LineNumber;
							lineno++;
						}
						else if (c == '\'') escaped = 1;
					}
				} while (escaped || c != stopc);
				echo(c);
				if (c == '\n')
					break;	/* Don't eat # */
				c = GetChar();
				continue;
				}
			case STNUM:
			/* The following code is quit ugly. This because
			 * ..3 == . .3 , whereas ...3 == ... 3
			 */
				echo(c);
				if (c == '.') {
					c = GetChar();
					if (c == '.') {
						if ((c = GetChar()) == '.') {
							echo('.'); echo('.');
							c = GetChar();
							continue;
						}
						UnGetChar();
						c = '.';
						continue;
					} else if (!is_dig(c)) {
						continue;
					} else echo(c);
				}
				c = GetChar();
				while (in_idf(c) || c == '.') {
					echo(c);
					if (c == 'e' || c == 'E') {
						c = GetChar();
						if (c == '+' || c == '-') {
							echo(c);
							c = GetChar();
						}
					} else	c = GetChar();
				}
				continue;
			case STELL:
				c = GetChar();
				UnGetChar();
				if (c == '"' || c == '\'') {
					echo('L');
					continue;
				}
				c = 'L';
			case STIDF: {
				extern int idfsize;		/* ??? */
				char buf[IDFSIZE + 1];
				register char *tg = &buf[0];
				register char *maxpos = &buf[idfsize];
				register struct idf *idef;
				int NoExpandNext = 0;

#define tstmac(bx)	if (!(bits[c] & bx)) goto nomac
#define cpy		*tg++ = c
#define load		c = GetChar(); if (!in_idf(c)) goto endidf

				/* unstack macro's when allowed. */
				if (Unstacked)
					EnableMacros();
				if (c == NOEXPM) {
					NoExpandNext = 1;
					c = GetChar();
				}

#ifdef DOBITS
				cpy; tstmac(bit0); load;
				cpy; tstmac(bit1); load;
				cpy; tstmac(bit2); load;
				cpy; tstmac(bit3); load;
				cpy; tstmac(bit4); load;
				cpy; tstmac(bit5); load;
				cpy; tstmac(bit6); load;
				cpy; tstmac(bit7); load;
#endif

				for(;;) {
					if (tg < maxpos) {
						cpy;
					}
					load;
				}
			endidf:
				if (c != EOF) UnGetChar();
				*tg = '\0';	/* mark the end of the identifier */
				if ((idef = findidf(buf))
				    && idef->id_macro
				    && ReplaceMacros && !NoExpandNext) {
					if (replace(idef)) {
						c = GetChar();
						continue;
					}
					tg = buf;
					while (*tg) {
						echo(*tg++);
					}
					c = GetChar();
					if (in_idf(c)) echo(' ');
					continue;
				}
			nomac:
				*tg = '\0';
				tg = buf;
				while (*tg) {
					echo(*tg++);
				}
				c = GetChar();
				while (in_idf(c)) {
					echo(c);
					c = GetChar();
				}
				continue;
				}
			case STMSPEC:
				if (InputLevel) {
					echo(' ');	/* seperate tokens */
					c = GetChar();
					continue;
				}
				/* else fallthrough */
			default:
			    	echo(c);
			    	c = GetChar();
			    	continue;
			}
			break;
		}
	}
	/*NOTREACHED*/
}

static char *
SkipComment(op, lineno)
char *op;
int *lineno;
{
	char *ob = &_obuf[OBUFSIZE];
	register int c;

	NoUnstack++;
	if (options['C']) {
		echo('/');
		echo('*');
	}
	c = GetChar();
	for(;;) {
		if (c == EOI) {
			newline();
			flush(op - _obuf);
			op = 0;
			break;
		}
		if (options['C']) {
			echo(c);
		}
		if (c == '\n') {
			++LineNumber;
			++*lineno;
			if (!options['C']) {
				echo(c);
			}
		}
		if (c == '*') {
			c = GetChar();
			if (c == '/') {
				if (options['C']) {
					echo(c);
				}
				break;			/* for(;;) */
			}
		} else c = GetChar();
	}
	NoUnstack--;
	return op;
}