pass2.c

操作系统源代码

ordinary_char:
				if (Str2word(s1, 1) != 0)
					return;
				Wordl++;
				if (*s1 == '.' || *s1 == '!'
				||  *s1 == '?' || *s1 == ':')
				    period = '.';
				else if (period == '.') {
				    nm[0] = *s1;
				    nm[1] = '\0';
				    if (regexec(Pat[13].pat, nm) == 0)
					 period = '\0';
				}
			}
		}
	    /*
	     * End of line processing
	     */
     		if (!Backc) {
			if (period == '.')
				Pass3(NOBREAK, (unsigned char *)"gap", NULL, 2);
			if (Centering > 0) {
				Pass3(DOBREAK, (unsigned char *)"center", NULL,
				0);
				Centering--;
			} else if (!Fill)
				Pass3(DOBREAK, (unsigned char *)"flush", NULL,
				0);
		}
		if (Aftnxt == NULL)
			return;
		/* else fall through to process an "after next trap */
	}
    /*
     * Special -man macro handling.
     */
	if (Marg == MANMACROS) {
	    /*
	     * A text line - "^[^.]" - is only processed when there is an
	     * "after next" directive.
	     */
		if (*line != '.' && *line != '\'') {
			if (Aftnxt != NULL) {
				if (regexec(Pat[9].pat, Aftnxt))  /* ",fP" */
					Font[0] = Prevfont;
				if (regexec(Pat[16].pat, Aftnxt))  /* ",fR" */
					Font[0] = 'R';
				if (regexec(Pat[10].pat, Aftnxt))  /* ",tP" */
					Pass3(DOBREAK,
						(unsigned char *)"toindent",
						NULL, 0);
				Free(&Aftnxt);
			}
			return;
		}
	    /*
	     * Special footer handling - "^.lF"
	     */
		if (line[1] == 'l' && line[2] == 'F') {
			s1 = Findstr((unsigned char *)"by", NULL, 0);
			s2 = Findstr((unsigned char *)"nb", NULL, 0);
			if (*s1 == '\0' || *s2 == '\0')
				(void) sprintf((char *)buf, "%s%s",
					(char *)s1, (char *)s2);
			else
				(void) sprintf((char *)buf, "%s; %s",
					(char *)s1, (char *)s2);
			Pass3(NOBREAK, (unsigned char *)"LF", buf, 0);
			return;
		}
	}
    /*
     * Special -ms macro handling.
     */
	if (Marg == MSMACROS) {
	    /*
	     * A text line - "^[^.]" - is only processed when there is an
	     * "after next" directive.
	     */
		if (*line != '.' && *line != '\'') {
			if (Aftnxt != NULL) {
				if (regexec(Pat[10].pat, Aftnxt))  /* ",tP" */
					Pass3(DOBREAK,
						(unsigned char *)"toindent",
						NULL, 0);
				Free(&Aftnxt);
			}
			return;
		}
	    /*
	     * Numbered headings - "^[.']nH"
	     */
		if (line[1] == 'n' && line[2] == 'H') {
			s1 = Field(2, line, 0);
			if (s1 != NULL) {
				i = atoi((char *)s1) - 1;	
				if (i < 0) {
					for (j = 0; j < MAXNHNR; j++) {
						Nhnr[j] = 0;
					}
					i = 0;
				} else if (i >= MAXNHNR) {
				    (void) sprintf((char *)buf,
					" over NH limit (%d)", MAXNHNR);
				    Error(WARN, LINE, (char *)buf, NULL);
				}
			} else
				i = 0;
			Nhnr[i]++;
			for (j = i + 1; j < MAXNHNR; j++) {
				Nhnr[j] = 0;
			}
			s1 = buf;
			for (j = 0; j <= i; j++) {
				(void) sprintf((char *)s1, "%d.", Nhnr[j]);
				s1 = buf + strlen((char *)buf);
			}
			(void) Findstr((unsigned char *)"Nh", buf, 1);
			return;
		}
	}
    /*
     * Remaining lines should begin with a '.' or '\'' unless an "after next"
     * trap has failed.
     */
	if (*line != '.' && *line != '\'') {
		if (Aftnxt != NULL)
			Error(WARN, LINE, " failed .it: ", (char *)Aftnxt);
		else
			Error(WARN, LINE, " unrecognized line ", NULL);
		return;
	}
	brk = (*line == '.') ? DOBREAK : NOBREAK;
    /*
     * Evaluate expressions for "^[.'](ta|ll|ls|in|ti|po|ne|sp|pl|nr)"
     * Then process the requests.
     */
	if (regexec(Pat[11].pat, &line[1])) {
	    /*
	     * Establish default scale factor.
	     */
		if ((line[1] == 'n' && line[2] == 'e')
		||  (line[1] == 's' && line[2] == 'p')
		||  (line[1] == 'p' && line[2] == 'l'))
			exscale = Scalev;
		else if (line[1] == 'n' && line[2] == 'r')
			exscale = Scaleu;
		else
			exscale = Scalen;
	    /*
	     * Determine starting argument.
	     */
		if (line[1] == 'n' && line[2] == 'r')
			s1 = Field(2, &line[3], 0);
		else
			s1 = Field(1, &line[3], 0);
	    /*
	     * Evaluate expressions.
	     */
		for (nexpr = 0; s1 != NULL &&*s1 != '\0'; ) {
			while (*s1 == ' ' || *s1 == '\t')
				s1++;
			if (*s1 == '+' || *s1 == '-')
				ssign = *s1++;
			else
				ssign = '\0';
		    /*
		     * Process terms.
		     */
			val = 0.0;
			sp = -1;
			c = '+';
			s1--;
			while (c == '+' || c == '*' || c == '%'
			||  c == ')' || c == '-' || c == '/') {
			    op = c;
			    s1++;
			    tscale = exscale;
			    tval = 0.0;
			/*
			 * Pop stack on right parenthesis.
			 */
			    if (op == ')') {
				tval = val;
				if (sp >= 0) {
				    val = valstack[sp];
				    op = opstack[sp];
				    sp--;
				} else {
				    Error(WARN, LINE,
					" expression stack underflow", NULL);
				    return;
				}
				tscale = Scaleu;
			/*
			 * Push stack on left parenthesis.
			 */
			    } else if (*s1 == '(') {
				sp++;
				if (sp >= MAXSP) {
				    Error(WARN, LINE,
				       " expression stack overflow", NULL);
				    return;
				}
				valstack[sp] = val;
				opstack[sp] = op;
				val = 0.0;
				c = '+';
				continue;
			    } else if (*s1 == '\\') {
			      s1++;
			      switch(*s1) {
			/*
			 * "\\"" begins a comment.
			 */
			      case '"':
				while (*s1)
					s1++;
				break;
			/*
			 * Crude width calculation for "\\w"
			 */
			      case 'w':
				s2 = ++s1;
				if (*s1) {
				    s1++;
				    while (*s1 && *s1 != *s2)
					s1++;
				    tval = (double) (s1 - s2 - 1) * Scalen;
				    if (*s1)
					s1++;
				}
				break;
			/*
			 * Interpolate number register if "\\n".
			 */
			      case 'n':
				s1 = Asmcode(&s1, nm);
				if ((i = Findnum(nm, 0, 0)) >= 0)
				    tval = Numb[i].val;
			        s1++;
			     }
			/*
			 * Assemble numeric value.
			 */
			    } else if (*s1 == '.' || isdigit(*s1)) {
				for (i = 0; isdigit(*s1) || *s1 == '.'; s1++) {
				    if (*s1 == '.') {
					i = 10;
					continue;
				    }
				    d = (double) (*s1 - '0');
				    if (i) {
					tval = tval + (d / (double) i);
					i = i * 10;
				    } else
					tval = (tval * 10.0) + d;
				}
			    } else {
			/*
			 * It's not an expression.  Ignore extra scale.
			 */
				if ((i = Findscale((int)*s1, 0.0, 0)) < 0) {
				    (void) sprintf((char *)buf,
					" \"%s\" isn't an expression",
					(char *)s1);
				    Error(WARN, LINE, (char *)buf, NULL);
				}
				s1++;
			    }
			/*
			 * Add term to expression value.
			 */
			    if ((i = Findscale((int)*s1, 0.0, 0)) >= 0) {
				tval *= Scale[i].val;
				s1++;
			    } else
				tval *= tscale;
			    switch (op) {
			    case '+':
				val += tval;
				break;
			    case '-':
				val -= tval;
				break;
			    case '*':
				val *= tval;
				break;
			    case '/':
			    case '%':
				i = (int) val;
				j = (int) tval;
				if (j == 0) {
				    Error(WARN, LINE,
					(*s1 == '/') ? "div" : "mod",
				        " by 0");
				    return;
				}
				if (op == '/')
					val = (double) (i / j);
				else
					val = (double) (i % j);
				break;
			    }
			    c = *s1;
			}
		    /*
		     * Save expression value and sign.
		     */
			if (nexpr >= MAXEXP) {
				(void) sprintf((char *)buf,
				    " at expression limit of %d", MAXEXP);
				Error(WARN, LINE, (char *)buf, NULL);
				return;
			}
			exsign[nexpr] = ssign;
			expr[nexpr] = val;
			if (ssign == '-')
				sexpr[nexpr] = -1.0 * val;
			else
				sexpr[nexpr] = val;
			nexpr++;
			while (*s1 == ' ' || *s1 == '\t')
				s1++;
		}
	    /*
	     * Set parameters "(ll|ls|in|ti|po|pl)"
	     */
		if (regexec(Pat[12].pat, &line[1])) {
			nm[0] = line[1];
			nm[1] = line[2];
			if ((i = Findparms(nm)) < 0) {
				Error(WARN, LINE,
				    " can't find parameter register ",
				    (char *)nm);
				return;
			}
			if (nexpr == 0 || exscale == 0.0)
				j = Parms[i].prev;
			else if (exsign[0] == '\0'
			     ||  (nm[0] == 't' && nm[1] == 'i'))
				 j = (int)(sexpr[0] / exscale);
			else
				j = Parms[i].val + (int)(sexpr[0] / exscale);
			Parms[i].prev = Parms[i].val;
			Parms[i].val = j;
			nm[0] = (nexpr) ? exsign[0] : '\0';     /* for .ti */
			nm[1] = '\0';
			Pass3(brk, (unsigned char *)Parms[i].cmd, nm, j);
			return;
		}
		if (line[1] == 'n') {
			switch(line[2]) {
	    /*
	     * Need - "^[.']ne <expression>"
	     */
			case 'e':
				if (nexpr && Scalev > 0.0)
					i = (int) ((expr[0]/Scalev) + 0.99);
				else
					i = 0;
				Pass3(DOBREAK, (unsigned char *)"need", NULL,
					i);
				return;
	    /*
	     * Number - "^[.']nr <name> <expression>"
	     */
			case 'r':
				if ((s1 = Field(2, line, 0)) == NULL) {
				    Error(WARN, LINE, " bad number register",
				        NULL);
				    return;
				}
				if ((i = Findnum(s1, 0, 0)) < 0)
				    i = Findnum(s1, 0, 1);
				if (nexpr < 1) {
				    Numb[i].val = 0;
				    return;
				}
				if (exsign[0] == '\0')
				    Numb[i].val = (int) expr[0];
				else
				    Numb[i].val += (int) sexpr[0];
				return;
			}
		}
	    /*
	     * Space - "^[.']sp <expression>"
	     */
		if (line[1] == 's' && line[2] == 'p') {
			if (nexpr == 0)
				i = 1;
			else
				i = (int)((expr[0] / Scalev) + 0.99);
			while (i--)
				Pass3(brk, (unsigned char *)"space", NULL, 0);
			return;
		}
	    /*
	     * Tab positions - "^[.']ta <pos1> <pos2> . . ."
	     */
     		if (line[1] == 't' && line[2] == 'a') {
			tval = 0.0;
			for (j = 0; j < nexpr; j++) {
				if (exsign[j] == '\0')
					tval = expr[j];
				else
					tval += sexpr[j];
				Tabs[j] = (int) (tval / Scalen);
			}
			Ntabs = nexpr;
			return;
		}
	}
    /*
     * Process all other nroff requests via Nreq().
     */
	(void) Nreq(line, brk);
	return;
}