ansi2knr.c
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上传日期:2007-01-07
资源大小:676k
文件大小:13k
- /* Copyright (C) 1989, 1991, 1993, 1994, 1995 Aladdin Enterprises. All rights reserved. */
- /* 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.
- 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 input_file [output_file]
- * 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.
- * It will recognize a multi-line header provided that the last character
- * of the last line of the header is a right parenthesis,
- * and no intervening line ends with a left or right brace or a semicolon.
- * These algorithms ignore whitespace and comments, 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).
- * - Macros that tinker with the syntax of the function header.
- */
- /*
- * 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 95-06-22 removed #ifndefs whose sole purpose was to define
- undefined preprocessor symbols as 0; changed all #ifdefs
- for configuration symbols to #ifs
- lpd 95-04-05 changed copyright notice to make it clear that
- including ansi2knr in a program does not bring the entire
- program under the GPL
- lpd 94-12-18 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 94-10-10 removed CONFIG_BROKETS conditional
- lpd 94-07-16 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 89-xx-xx original version
- */
- /* Most of the conditionals here are to make ansi2knr work with */
- /* 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 */
- /*
- Without AC_CONFIG_HEADER, merely use <string.h> as in the original
- Ghostscript distribution. This loses on older BSD systems.
- */
- # include <string.h>
- #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.
- */
- char *malloc();
- void free();
- #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 *skipspace();
- void writeblanks();
- int test1();
- int convert1();
- /* The main program */
- int
- main(argc, argv)
- int argc;
- char *argv[];
- { FILE *in, *out;
- #define bufsize 5000 /* arbitrary size */
- char *buf;
- char *line;
- /*
- * 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;
- if ( argc > 1 && argv[1][0] == '-' )
- { if ( !strcmp(argv[1], "--varargs") )
- { convert_varargs = 1;
- argc--;
- argv++;
- }
- else
- { fprintf(stderr, "Unrecognized switch: %sn", argv[1]);
- exit(1);
- }
- }
- switch ( argc )
- {
- default:
- printf("Usage: ansi2knr input_file [output_file]n");
- exit(0);
- case 2:
- out = stdout;
- break;
- case 3:
- out = fopen(argv[2], "w");
- if ( out == NULL )
- { fprintf(stderr, "Cannot open output file %sn", argv[2]);
- exit(1);
- }
- }
- in = fopen(argv[1], "r");
- if ( in == NULL )
- { fprintf(stderr, "Cannot open input file %sn", argv[1]);
- exit(1);
- }
- fprintf(out, "#line 1 "%s"n", argv[1]);
- buf = malloc(bufsize);
- line = buf;
- while ( fgets(line, (unsigned)(buf + bufsize - line), in) != NULL )
- { switch ( test1(buf) )
- {
- case 2: /* a function header */
- convert1(buf, out, 1, convert_varargs);
- break;
- case 1: /* a function */
- convert1(buf, out, 0, convert_varargs);
- break;
- case -1: /* maybe the start of a function */
- line = buf + strlen(buf);
- if ( line != buf + (bufsize - 1) ) /* overflow check */
- continue;
- /* falls through */
- default: /* not a function */
- fputs(buf, out);
- break;
- }
- line = buf;
- }
- if ( line != buf ) fputs(buf, out);
- free(buf);
- fclose(out);
- fclose(in);
- return 0;
- }
- /* Skip over space and comments, in either direction. */
- char *
- skipspace(p, dir)
- register char *p;
- register 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;
- }
- /*
- * Write blanks over part of a string.
- * Don't overwrite end-of-line characters.
- */
- void
- writeblanks(start, end)
- char *start;
- char *end;
- { char *p;
- for ( p = start; p < end; p++ )
- if ( *p != 'r' && *p != 'n' ) *p = ' ';
- }
- /*
- * 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;
- { register char *p = buf;
- char *bend;
- char *endfn;
- int contin;
- if ( !isidfirstchar(*p) )
- return 0; /* no name at left margin */
- bend = skipspace(buf + strlen(buf) - 1, -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;
- int len = endfn - buf;
- while ( (kp = *key) != 0 )
- { if ( strlen(kp) == len && !strncmp(kp, buf, len) )
- return 0; /* name is a keyword */
- key++;
- }
- }
- 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;
- register char *p;
- 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 == 0 )
- { /* 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;
- 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 '/':
- p = skipspace(p, 1) - 1;
- break;
- default:
- ;
- }
- }
- /* Erase any embedded prototype parameters. */
- if ( lp )
- 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 '/': p = skipspace(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;
- }