Minix1.5/commands/elvis/ctags.c
/* ctags.c */
/* Author:
* Steve Kirkendall
* 16820 SW Tallac Way
* Beaverton, OR 97006
* kirkenda@jove.cs.pdx.edu, or ...uunet!tektronix!psueea!jove!kirkenda
*/
/* This file contains the complete source to the ctags program. */
/* Special abilities:
* Can also make a "refs" file for use by the "ref" program.
*/
/* Limitations:
* This version of ctags always writes its output to the file "tags".
* It assumes that every command-line argument (but "-r") is a C source file.
* It does not sort the list of tags.
* It does not recognize duplicate definitions.
* It does not try to handle "static" functions in a clever way.
* It probably won't scan ANSI-C source code very well.
*/
/* Implementation:
* Lines are scanned one-at-a-time.
* The context of lines is tracked via a finite state machine.
* Contexts are:
* EXPECTFN - we're looking for a function name.
* ARGS - between function name and its opening {
* BODY - we found a function name, skip to end of body.
*
* Function tags are referenced by a search string, so that lines may be
* inserted or deleted without mucking up the tag search.
*
* Macro tags are referenced by their line number, because 1) they usually
* occur near the top of a file, so their line# won't change much; 2) They
* often contain characters that are hard to search for; and 3) Their #define
* line is likely to be altered.
*
* Each line of the resulting "tags" file describes one tag. Lines begin with
* the tag name, then a tab, then the file name, then a tab, and then either
* a line number or a slash-delimited search string.
*/
#include <ctype.h>
#include <stdio.h>
#define TAGS "tags"
#define REFS "refs"
#define NUMFMT "%.*s\t%s\t%ld\n"
#define SRCHFMT "%.*s\t%s\t/^%s$/\n"
#define MAINFMT "M%.*s\t%s\t/^%s$/\n"
#ifdef VERBOSE
# define SAY(x) fprintf(stderr, "%s\n", x);
#else
# define SAY(x)
#endif
#define EXPECTFN 1
#define ARGS 2
#define BODY 3
extern char *fgets();
char *progname; /* argv[0], used for diagnostic output */
main(argc, argv)
int argc;
char **argv;
{
FILE *fp;
int i;
FILE *refs; /* used to write to the refs file */
/* notice the program name */
progname = argv[0];
/* create the "refs" file if first arg is "-r" */
if (argc > 1 && !strcmp(argv[1], "-r"))
{
/* delete the "-r" flag from the args list */
argc--;
argv++;
/* open the "refs" file for writing */
refs = fopen(REFS, "w");
if (!refs)
{
fprintf(stderr, "%s: could not create \"%s\"\n", progname, REFS);
exit(2);
}
}
else
{
refs = (FILE *)0;
}
/* process each file named on the command line, or complain if none */
if (argc > 1)
{
/* redirect stdout to go to the "tags" file */
if (!freopen("tags", "w", stdout))
{
fprintf(stderr, "%s: could not create \"%s\"\n", progname, TAGS);
exit(2);
}
for (i = 1; i < argc; i++)
{
/* process this named file */
fp = fopen(argv[i], "r");
if (!fp)
{
fprintf(stderr, "%s: could not read \"%s\"\n", argv[0], argv[i]);
continue;
}
ctags(fp, argv[i], refs);
fclose(fp);
}
#ifdef SORT
/* This is a hack which will sort the tags list. It should
* on UNIX and Minix. You may have trouble with csh. Note
* that the tags list only has to be sorted if you intend to
* use it with the real vi; elvis permits unsorted tags.
*/
fflush(stdout);
system("sort tags >_tags$$; mv _tags$$ tags");
#endif
exit(0);
}
else
{
fprintf(stderr, "usage: %s *.[ch]\n", argv[0]);
exit(2);
}
}
/* this function finds all tags in a given file */
ctags(fp, name, refs)
FILE *fp; /* stream of the file to scan */
char *name; /* name of the file being scanned */
FILE *refs; /* NULL, or where to write refs lines */
{
int context; /* context - either EXPECTFN, ARGS, or BODY */
long lnum; /* line number */
char text[1000]; /* a line of text from the file */
char *scan; /* used for searching through text */
int len; /* length of the line */
/* for each line of the file... */
for (context = EXPECTFN, lnum = 1; fgets(text, sizeof text, fp); lnum++)
{
#ifdef VERBOSE
switch(context)
{
case EXPECTFN: scan = "EXPECTFN"; break;
case ARGS: scan = "ARGS "; break;
case BODY: scan = "BODY "; break;
default: scan = "context?";
}
fprintf(stderr, "%s:%s", scan, text);
#endif
/* start of body? */
if (text[0] == '{')
{
context = BODY;
SAY("Start of BODY");
continue;
}
/* argument line, to be written to "refs" ? */
if (refs && context == ARGS)
{
if (text[0] != '\t')
{
putc('\t', refs);
}
fputs(text, refs);
SAY("Argument line");
continue;
}
/* ignore empty or indented lines */
if (text[0] <= ' ')
{
SAY("Empty or indented");
continue;
}
/* end of body? */
if (text[0] == '}')
{
context = EXPECTFN;
SAY("End of BODY");
continue;
}
/* ignore lines in the body of a function */
if (context != EXPECTFN)
{
SAY("BODY or ARGS");
continue;
}
/* strip the newline */
len = strlen(text);
text[--len] = '\0';
/* a preprocessor line? */
if (text[0] == '#')
{
/* find the preprocessor directive */
for (scan = &text[1]; isspace(*scan); scan++)
{
}
/* if it's a #define, make a tag out of it */
if (!strncmp(scan, "define", 6))
{
/* find the start of the symbol name */
for (scan += 6; isspace(*scan); scan++)
{
}
/* find the length of the symbol name */
for (len = 1;
isalnum(scan[len]) || scan[len] == '_';
len++)
{
}
printf(NUMFMT, len, scan, name, lnum);
}
SAY("Preprocessor line");
continue;
}
/* an extern or static declaration? */
if (text[len - 1] == ';'
|| !strncmp(text, "extern", 6)
|| !strncmp(text, "EXTERN", 6)
|| !strncmp(text, "static", 6)
|| !strncmp(text, "PRIVATE", 7))
{
SAY("Extern or static");
continue;
}
/* if we get here & the first punctuation other than "*" is
* a "(" which is immediately preceded by a name, then
* assume the name is that of a function.
*/
for (scan = text; *scan; scan++)
{
if (ispunct(*scan)
&& !isspace(*scan) /* in BSD, spaces are punctuation?*/
&& *scan != '*' && *scan != '_' && *scan != '(')
{
SAY("Funny punctuation");
goto ContinueContinue;
}
if (*scan == '(')
{
/* permit 0 or 1 spaces between name & '(' */
if (scan > text && scan[-1] == ' ')
{
scan--;
}
/* find the start & length of the name */
for (len = 0, scan--;
scan >= text && (isalnum(*scan) || *scan == '_');
scan--, len++)
{
}
scan++;
/* did we find a function? */
if (len > 0)
{
/* found a function! */
if (len == 4 && !strncmp(scan, "main", 4))
{
printf(MAINFMT, strlen(name) - 2, name, name, text);
}
printf(SRCHFMT, len, scan, name, text);
context = ARGS;
/* add a line to refs, if needed */
if (refs)
{
fputs(text, refs);
putc('\n', refs);
}
goto ContinueContinue;
}
}
else
{
SAY("No parenthesis");
}
}
SAY("No punctuation");
ContinueContinue:;
}
}