Ghostscript 6.0

src/ansi2knr.c

@@ -0,0 +1,720 @@
+/* Copyright (C) 1989, 1997, 1998, 1999 Aladdin Enterprises.  All rights reserved. */
+
+/*$Id: ansi2knr.c $*/
+/* Convert ANSI C function definitions to K&R ("traditional C") syntax */
+
+/*
+ansi2knr is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY.  No author or distributor accepts responsibility to anyone for the
+consequences of using it or for whether it serves any particular purpose or
+works at all, unless he says so in writing.  Refer to the GNU General Public
+License (the "GPL") for full details.
+
+Everyone is granted permission to copy, modify and redistribute ansi2knr,
+but only under the conditions described in the GPL.  A copy of this license
+is supposed to have been given to you along with ansi2knr so you can know
+your rights and responsibilities.  It should be in a file named COPYLEFT,
+or, if there is no file named COPYLEFT, a file named COPYING.  Among other
+things, the copyright notice and this notice must be preserved on all
+copies.
+
+We explicitly state here what we believe is already implied by the GPL: if
+the ansi2knr program is distributed as a separate set of sources and a
+separate executable file which are aggregated on a storage medium together
+with another program, this in itself does not bring the other program under
+the GPL, nor does the mere fact that such a program or the procedures for
+constructing it invoke the ansi2knr executable bring any other part of the
+program under the GPL.
+*/
+
+/*
+ * Usage:
+	ansi2knr [--filename FILENAME] [INPUT_FILE [OUTPUT_FILE]]
+ * --filename provides the file name for the #line directive in the output,
+ * overriding input_file (if present).
+ * If no input_file is supplied, input is read from stdin.
+ * If no output_file is supplied, output goes to stdout.
+ * There are no error messages.
+ *
+ * ansi2knr recognizes function definitions by seeing a non-keyword
+ * identifier at the left margin, followed by a left parenthesis, with a
+ * right parenthesis as the last character on the line, and with a left
+ * brace as the first token on the following line (ignoring possible
+ * intervening comments and/or preprocessor directives), except that a line
+ * consisting of only
+ *	identifier1(identifier2)
+ * will not be considered a function definition unless identifier2 is
+ * the word "void", and a line consisting of
+ *	identifier1(identifier2, <<arbitrary>>)
+ * will not be considered a function definition.
+ * ansi2knr will recognize a multi-line header provided that no intervening
+ * line ends with a left or right brace or a semicolon.  These algorithms
+ * ignore whitespace, comments, and preprocessor directives, except that
+ * the function name must be the first thing on the line.  The following
+ * constructs will confuse it:
+ *	- Any other construct that starts at the left margin and
+ *	    follows the above syntax (such as a macro or function call).
+ *	- Some macros that tinker with the syntax of function headers.
+ */
+
+/*
+ * The original and principal author of ansi2knr is L. Peter Deutsch
+ * <ghost@aladdin.com>.  Other authors are noted in the change history
+ * that follows (in reverse chronological order):
+	lpd 1999-08-17 added code to allow preprocessor directives
+		wherever comments are allowed
+	lpd 1999-04-12 added minor fixes from Pavel Roskin
+		<pavel_roskin@geocities.com> for clean compilation with
+		gcc -W -Wall
+	lpd 1999-03-22 added hack to recognize lines consisting of
+		identifier1(identifier2, xxx) as *not* being procedures
+	lpd 1999-02-03 made indentation of preprocessor commands consistent
+	lpd 1999-01-28 fixed two bugs: a '/' in an argument list caused an
+		endless loop; quoted strings within an argument list
+		confused the parser
+	lpd 1999-01-24 added a check for write errors on the output,
+		suggested by Jim Meyering <meyering@ascend.com>
+	lpd 1998-11-09 added further hack to recognize identifier(void)
+		as being a procedure
+	lpd 1998-10-23 added hack to recognize lines consisting of
+		identifier1(identifier2) as *not* being procedures
+	lpd 1997-12-08 made input_file optional; only closes input and/or
+		output file if not stdin or stdout respectively; prints
+		usage message on stderr rather than stdout; adds
+		--filename switch (changes suggested by
+		<ceder@lysator.liu.se>)
+	lpd 1996-01-21 added code to cope with not HAVE_CONFIG_H and with
+		compilers that don't understand void, as suggested by
+		Tom Lane
+	lpd 1996-01-15 changed to require that the first non-comment token
+		on the line following a function header be a left brace,
+		to reduce sensitivity to macros, as suggested by Tom Lane
+		<tgl@sss.pgh.pa.us>
+	lpd 1995-06-22 removed #ifndefs whose sole purpose was to define
+		undefined preprocessor symbols as 0; changed all #ifdefs
+		for configuration symbols to #ifs
+	lpd 1995-04-05 changed copyright notice to make it clear that
+		including ansi2knr in a program does not bring the entire
+		program under the GPL
+	lpd 1994-12-18 added conditionals for systems where ctype macros
+		don't handle 8-bit characters properly, suggested by
+		Francois Pinard <pinard@iro.umontreal.ca>;
+		removed --varargs switch (this is now the default)
+	lpd 1994-10-10 removed CONFIG_BROKETS conditional
+	lpd 1994-07-16 added some conditionals to help GNU `configure',
+		suggested by Francois Pinard <pinard@iro.umontreal.ca>;
+		properly erase prototype args in function parameters,
+		contributed by Jim Avera <jima@netcom.com>;
+		correct error in writeblanks (it shouldn't erase EOLs)
+	lpd 1989-xx-xx original version
+ */
+
+/* Most of the conditionals here are to make ansi2knr work with */
+/* or without the GNU configure machinery. */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#include <ctype.h>
+
+#if HAVE_CONFIG_H
+
+/*
+   For properly autoconfiguring ansi2knr, use AC_CONFIG_HEADER(config.h).
+   This will define HAVE_CONFIG_H and so, activate the following lines.
+ */
+
+# if STDC_HEADERS || HAVE_STRING_H
+#  include <string.h>
+# else
+#  include <strings.h>
+# endif
+
+#else /* not HAVE_CONFIG_H */
+
+/* Otherwise do it the hard way */
+
+# ifdef BSD
+#  include <strings.h>
+# else
+#  ifdef VMS
+    extern int strlen(), strncmp();
+#  else
+#   include <string.h>
+#  endif
+# endif
+
+#endif /* not HAVE_CONFIG_H */
+
+#if STDC_HEADERS
+# include <stdlib.h>
+#else
+/*
+   malloc and free should be declared in stdlib.h,
+   but if you've got a K&R compiler, they probably aren't.
+ */
+# ifdef MSDOS
+#  include <malloc.h>
+# else
+#  ifdef VMS
+     extern char *malloc();
+     extern void free();
+#  else
+     extern char *malloc();
+     extern int free();
+#  endif
+# endif
+
+#endif
+
+/* Define NULL (for *very* old compilers). */
+#ifndef NULL
+# define NULL (0)
+#endif
+
+/*
+ * The ctype macros don't always handle 8-bit characters correctly.
+ * Compensate for this here.
+ */
+#ifdef isascii
+# undef HAVE_ISASCII		/* just in case */
+# define HAVE_ISASCII 1
+#else
+#endif
+#if STDC_HEADERS || !HAVE_ISASCII
+# define is_ascii(c) 1
+#else
+# define is_ascii(c) isascii(c)
+#endif
+
+#define is_space(c) (is_ascii(c) && isspace(c))
+#define is_alpha(c) (is_ascii(c) && isalpha(c))
+#define is_alnum(c) (is_ascii(c) && isalnum(c))
+
+/* Scanning macros */
+#define isidchar(ch) (is_alnum(ch) || (ch) == '_')
+#define isidfirstchar(ch) (is_alpha(ch) || (ch) == '_')
+
+/* Forward references */
+char *ppdirforward();
+char *ppdirbackward();
+char *skipspace();
+char *scanstring();
+int writeblanks();
+int test1();
+int convert1();
+
+/* The main program */
+int
+main(argc, argv)
+    int argc;
+    char *argv[];
+{	FILE *in = stdin;
+	FILE *out = stdout;
+	char *filename = 0;
+	char *program_name = argv[0];
+	char *output_name = 0;
+#define bufsize 5000			/* arbitrary size */
+	char *buf;
+	char *line;
+	char *more;
+	char *usage =
+	  "Usage: ansi2knr [--filename FILENAME] [INPUT_FILE [OUTPUT_FILE]]\n";
+	/*
+	 * In previous versions, ansi2knr recognized a --varargs switch.
+	 * If this switch was supplied, ansi2knr would attempt to convert
+	 * a ... argument to va_alist and va_dcl; if this switch was not
+	 * supplied, ansi2knr would simply drop any such arguments.
+	 * Now, ansi2knr always does this conversion, and we only
+	 * check for this switch for backward compatibility.
+	 */
+	int convert_varargs = 1;
+	int output_error;
+
+	while ( argc > 1 && argv[1][0] == '-' ) {
+	  if ( !strcmp(argv[1], "--varargs") ) {
+	    convert_varargs = 1;
+	    argc--;
+	    argv++;
+	    continue;
+	  }
+	  if ( !strcmp(argv[1], "--filename") && argc > 2 ) {
+	    filename = argv[2];
+	    argc -= 2;
+	    argv += 2;
+	    continue;
+	  }
+	  fprintf(stderr, "%s: Unrecognized switch: %s\n", program_name,
+		  argv[1]);
+	  fprintf(stderr, usage);
+	  exit(1);
+	}
+	switch ( argc )
+	   {
+	default:
+		fprintf(stderr, usage);
+		exit(0);
+	case 3:
+		output_name = argv[2];
+		out = fopen(output_name, "w");
+		if ( out == NULL ) {
+		  fprintf(stderr, "%s: Cannot open output file %s\n",
+			  program_name, output_name);
+		  exit(1);
+		}
+		/* falls through */
+	case 2:
+		in = fopen(argv[1], "r");
+		if ( in == NULL ) {
+		  fprintf(stderr, "%s: Cannot open input file %s\n",
+			  program_name, argv[1]);
+		  exit(1);
+		}
+		if ( filename == 0 )
+		  filename = argv[1];
+		/* falls through */
+	case 1:
+		break;
+	   }
+	if ( filename )
+	  fprintf(out, "#line 1 \"%s\"\n", filename);
+	buf = malloc(bufsize);
+	if ( buf == NULL )
+	   {
+		fprintf(stderr, "Unable to allocate read buffer!\n");
+		exit(1);
+	   }
+	line = buf;
+	while ( fgets(line, (unsigned)(buf + bufsize - line), in) != NULL )
+	   {
+test:		line += strlen(line);
+		switch ( test1(buf) )
+		   {
+		case 2:			/* a function header */
+			convert1(buf, out, 1, convert_varargs);
+			break;
+		case 1:			/* a function */
+			/* Check for a { at the start of the next line. */
+			more = ++line;
+f:			if ( line >= buf + (bufsize - 1) ) /* overflow check */
+			  goto wl;
+			if ( fgets(line, (unsigned)(buf + bufsize - line), in) == NULL )
+			  goto wl;
+			switch ( *skipspace(ppdirforward(more), 1) )
+			  {
+			  case '{':
+			    /* Definitely a function header. */
+			    convert1(buf, out, 0, convert_varargs);
+			    fputs(more, out);
+			    break;
+			  case 0:
+			    /* The next line was blank or a comment: */
+			    /* keep scanning for a non-comment. */
+			    line += strlen(line);
+			    goto f;
+			  default:
+			    /* buf isn't a function header, but */
+			    /* more might be. */
+			    fputs(buf, out);
+			    strcpy(buf, more);
+			    line = buf;
+			    goto test;
+			  }
+			break;
+		case -1:		/* maybe the start of a function */
+			if ( line != buf + (bufsize - 1) ) /* overflow check */
+			  continue;
+			/* falls through */
+		default:		/* not a function */
+wl:			fputs(buf, out);
+			break;
+		   }
+		line = buf;
+	   }
+	if ( line != buf )
+	  fputs(buf, out);
+	free(buf);
+	if ( output_name ) {
+	  output_error = ferror(out);
+	  output_error |= fclose(out);
+	} else {		/* out == stdout */
+	  fflush(out);
+	  output_error = ferror(out);
+	}
+	if ( output_error ) {
+	  fprintf(stderr, "%s: error writing to %s\n", program_name,
+		  (output_name ? output_name : "stdout"));
+	  exit(1);
+	}
+	if ( in != stdin )
+	  fclose(in);
+	return 0;
+}
+
+/*
+ * Skip forward or backward over one or more preprocessor directives.
+ */
+char *
+ppdirforward(p)
+    char *p;
+{
+    for (; *p == '#'; ++p) {
+	for (; *p != '\r' && *p != '\n'; ++p)
+	    if (*p == 0)
+		return p;
+	if (*p == '\r' && p[1] == '\n')
+	    ++p;
+    }
+    return p;
+}
+char *
+ppdirbackward(p, limit)
+    char *p;
+    char *limit;
+{
+    char *np = p;
+
+    for (;; p = --np) {
+	if (*np == '\n' && np[-1] == '\r')
+	    --np;
+	for (; np > limit && np[-1] != '\r' && np[-1] != '\n'; --np)
+	    if (np[-1] == 0)
+		return np;
+	if (*np != '#')
+	    return p;
+    }
+}
+
+/*
+ * Skip over whitespace, comments, and preprocessor directives,
+ * in either direction.
+ */
+char *
+skipspace(p, dir)
+    char *p;
+    int dir;			/* 1 for forward, -1 for backward */
+{
+    for ( ; ; ) {
+	while ( is_space(*p) )
+	    p += dir;
+	if ( !(*p == '/' && p[dir] == '*') )
+	    break;
+	p += dir;  p += dir;
+	while ( !(*p == '*' && p[dir] == '/') ) {
+	    if ( *p == 0 )
+		return p;	/* multi-line comment?? */
+	    p += dir;
+	}
+	p += dir;  p += dir;
+    }
+    return p;
+}
+
+/* Scan over a quoted string, in either direction. */
+char *
+scanstring(p, dir)
+    char *p;
+    int dir;
+{
+    for (p += dir; ; p += dir)
+	if (*p == '"' && p[-dir] != '\\')
+	    return p + dir;
+}
+
+/*
+ * Write blanks over part of a string.
+ * Don't overwrite end-of-line characters.
+ */
+int
+writeblanks(start, end)
+    char *start;
+    char *end;
+{	char *p;
+	for ( p = start; p < end; p++ )
+	  if ( *p != '\r' && *p != '\n' )
+	    *p = ' ';
+	return 0;
+}
+
+/*
+ * Test whether the string in buf is a function definition.
+ * The string may contain and/or end with a newline.
+ * Return as follows:
+ *	0 - definitely not a function definition;
+ *	1 - definitely a function definition;
+ *	2 - definitely a function prototype (NOT USED);
+ *	-1 - may be the beginning of a function definition,
+ *		append another line and look again.
+ * The reason we don't attempt to convert function prototypes is that
+ * Ghostscript's declaration-generating macros look too much like
+ * prototypes, and confuse the algorithms.
+ */
+int
+test1(buf)
+    char *buf;
+{	char *p = buf;
+	char *bend;
+	char *endfn;
+	int contin;
+
+	if ( !isidfirstchar(*p) )
+	  return 0;		/* no name at left margin */
+	bend = skipspace(ppdirbackward(buf + strlen(buf) - 1, buf), -1);
+	switch ( *bend )
+	   {
+	   case ';': contin = 0 /*2*/; break;
+	   case ')': contin = 1; break;
+	   case '{': return 0;		/* not a function */
+	   case '}': return 0;		/* not a function */
+	   default: contin = -1;
+	   }
+	while ( isidchar(*p) )
+	  p++;
+	endfn = p;
+	p = skipspace(p, 1);
+	if ( *p++ != '(' )
+	  return 0;		/* not a function */
+	p = skipspace(p, 1);
+	if ( *p == ')' )
+	  return 0;		/* no parameters */
+	/* Check that the apparent function name isn't a keyword. */
+	/* We only need to check for keywords that could be followed */
+	/* by a left parenthesis (which, unfortunately, is most of them). */
+	   {	static char *words[] =
+		   {	"asm", "auto", "case", "char", "const", "double",
+			"extern", "float", "for", "if", "int", "long",
+			"register", "return", "short", "signed", "sizeof",
+			"static", "switch", "typedef", "unsigned",
+			"void", "volatile", "while", 0
+		   };
+		char **key = words;
+		char *kp;
+		unsigned len = endfn - buf;
+
+		while ( (kp = *key) != 0 )
+		   {	if ( strlen(kp) == len && !strncmp(kp, buf, len) )
+			  return 0;	/* name is a keyword */
+			key++;
+		   }
+	   }
+	   {
+	       char *id = p;
+	       int len;
+	       /*
+		* Check for identifier1(identifier2) and not
+		* identifier1(void), or identifier1(identifier2, xxxx).
+		*/
+
+	       while ( isidchar(*p) )
+		   p++;
+	       len = p - id;
+	       p = skipspace(p, 1);
+	       if (*p == ',' ||
+		   (*p == ')' && (len != 4 || strncmp(id, "void", 4)))
+		   )
+		   return 0;	/* not a function */
+	   }
+	/*
+	 * If the last significant character was a ), we need to count
+	 * parentheses, because it might be part of a formal parameter
+	 * that is a procedure.
+	 */
+	if (contin > 0) {
+	    int level = 0;
+
+	    for (p = skipspace(buf, 1); *p; p = skipspace(p + 1, 1))
+		level += (*p == '(' ? 1 : *p == ')' ? -1 : 0);
+	    if (level > 0)
+		contin = -1;
+	}
+	return contin;
+}
+
+/* Convert a recognized function definition or header to K&R syntax. */
+int
+convert1(buf, out, header, convert_varargs)
+    char *buf;
+    FILE *out;
+    int header;			/* Boolean */
+    int convert_varargs;	/* Boolean */
+{	char *endfn;
+	char *p;
+	/*
+	 * The breaks table contains pointers to the beginning and end
+	 * of each argument.
+	 */
+	char **breaks;
+	unsigned num_breaks = 2;	/* for testing */
+	char **btop;
+	char **bp;
+	char **ap;
+	char *vararg = 0;
+
+	/* Pre-ANSI implementations don't agree on whether strchr */
+	/* is called strchr or index, so we open-code it here. */
+	for ( endfn = buf; *(endfn++) != '('; )
+	  ;
+top:	p = endfn;
+	breaks = (char **)malloc(sizeof(char *) * num_breaks * 2);
+	if ( breaks == NULL )
+	   {	/* Couldn't allocate break table, give up */
+		fprintf(stderr, "Unable to allocate break table!\n");
+		fputs(buf, out);
+		return -1;
+	   }
+	btop = breaks + num_breaks * 2 - 2;
+	bp = breaks;
+	/* Parse the argument list */
+	do
+	   {	int level = 0;
+		char *lp = NULL;
+		char *rp = NULL;
+		char *end = NULL;
+
+		if ( bp >= btop )
+		   {	/* Filled up break table. */
+			/* Allocate a bigger one and start over. */
+			free((char *)breaks);
+			num_breaks <<= 1;
+			goto top;
+		   }
+		*bp++ = p;
+		/* Find the end of the argument */
+		for ( ; end == NULL; p++ )
+		   {	switch(*p)
+			   {
+			   case ',':
+				if ( !level ) end = p;
+				break;
+			   case '(':
+				if ( !level ) lp = p;
+				level++;
+				break;
+			   case ')':
+				if ( --level < 0 ) end = p;
+				else rp = p;
+				break;
+			   case '/':
+				if (p[1] == '*')
+				    p = skipspace(p, 1) - 1;
+				break;
+			   case '"':
+			       p = scanstring(p, 1) - 1;
+			       break;
+			   default:
+				;
+			   }
+		   }
+		/* Erase any embedded prototype parameters. */
+		if ( lp && rp )
+		  writeblanks(lp + 1, rp);
+		p--;			/* back up over terminator */
+		/* Find the name being declared. */
+		/* This is complicated because of procedure and */
+		/* array modifiers. */
+		for ( ; ; )
+		   {	p = skipspace(p - 1, -1);
+			switch ( *p )
+			   {
+			   case ']':	/* skip array dimension(s) */
+			   case ')':	/* skip procedure args OR name */
+			   {	int level = 1;
+				while ( level )
+				 switch ( *--p )
+				   {
+				   case ']': case ')':
+				       level++;
+				       break;
+				   case '[': case '(':
+				       level--;
+				       break;
+				   case '/':
+				       if (p > buf && p[-1] == '*')
+					   p = skipspace(p, -1) + 1;
+				       break;
+				   case '"':
+				       p = scanstring(p, -1) + 1;
+				       break;
+				   default: ;
+				   }
+			   }
+				if ( *p == '(' && *skipspace(p + 1, 1) == '*' )
+				   {	/* We found the name being declared */
+					while ( !isidfirstchar(*p) )
+					  p = skipspace(p, 1) + 1;
+					goto found;
+				   }
+				break;
+			   default:
+				goto found;
+			   }
+		   }
+found:		if ( *p == '.' && p[-1] == '.' && p[-2] == '.' )
+		  {	if ( convert_varargs )
+			  {	*bp++ = "va_alist";
+				vararg = p-2;
+			  }
+			else
+			  {	p++;
+				if ( bp == breaks + 1 )	/* sole argument */
+				  writeblanks(breaks[0], p);
+				else
+				  writeblanks(bp[-1] - 1, p);
+				bp--;
+			  }
+		   }
+		else
+		   {	while ( isidchar(*p) ) p--;
+			*bp++ = p+1;
+		   }
+		p = end;
+	   }
+	while ( *p++ == ',' );
+	*bp = p;
+	/* Make a special check for 'void' arglist */
+	if ( bp == breaks+2 )
+	   {	p = skipspace(breaks[0], 1);
+		if ( !strncmp(p, "void", 4) )
+		   {	p = skipspace(p+4, 1);
+			if ( p == breaks[2] - 1 )
+			   {	bp = breaks;	/* yup, pretend arglist is empty */
+				writeblanks(breaks[0], p + 1);
+			   }
+		   }
+	   }
+	/* Put out the function name and left parenthesis. */
+	p = buf;
+	while ( p != endfn ) putc(*p, out), p++;
+	/* Put out the declaration. */
+	if ( header )
+	  {	fputs(");", out);
+		for ( p = breaks[0]; *p; p++ )
+		  if ( *p == '\r' || *p == '\n' )
+		    putc(*p, out);
+	  }
+	else
+	  {	for ( ap = breaks+1; ap < bp; ap += 2 )
+		  {	p = *ap;
+			while ( isidchar(*p) )
+			  putc(*p, out), p++;
+			if ( ap < bp - 1 )
+			  fputs(", ", out);
+		  }
+		fputs(")  ", out);
+		/* Put out the argument declarations */
+		for ( ap = breaks+2; ap <= bp; ap += 2 )
+		  (*ap)[-1] = ';';
+		if ( vararg != 0 )
+		  {	*vararg = 0;
+			fputs(breaks[0], out);		/* any prior args */
+			fputs("va_dcl", out);		/* the final arg */
+			fputs(bp[0], out);
+		  }
+		else
+		  fputs(breaks[0], out);
+	  }
+	free((char *)breaks);
+	return 0;
+}