/* $OpenBSD: tags.c,v 1.17 2022/01/28 06:18:41 guenther Exp $ */
/*
* This file is in the public domain.
*
* Author: Sunil Nimmagadda <sunil@openbsd.org>
*/
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/tree.h>
#include <sys/types.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#if defined(LIBBSD_OVERLAY) || defined(__FreeBSD__) || defined(__DragonFly__) || defined(__GLIBC__)
# include <libutil.h>
#else
#include <util.h>
#endif
#include "def.h"
struct ctag;
static int addctag(char *);
static int atbow(void);
void closetags(void);
static int ctagcmp(struct ctag *, struct ctag *);
static int loadbuffer(char *);
static int loadtags(const char *);
static int pushtag(char *);
static int searchpat(char *);
static struct ctag *searchtag(char *);
static char *strip(char *, size_t);
static void unloadtags(void);
#define DEFAULTFN "tags"
char *tagsfn = NULL;
int loaded = FALSE;
/* ctags(1) entries are parsed and maintained in a tree. */
struct ctag {
RB_ENTRY(ctag) entry;
char *tag;
char *fname;
char *pat;
};
RB_HEAD(tagtree, ctag) tags = RB_INITIALIZER(&tags);
#ifdef __DragonFly__
RB_PROTOTYPE(tagtree, ctag, entry, ctagcmp);
#endif
RB_GENERATE(tagtree, ctag, entry, ctagcmp);
struct tagpos {
SLIST_ENTRY(tagpos) entry;
int doto;
int dotline;
char *bname;
};
SLIST_HEAD(tagstack, tagpos) shead = SLIST_HEAD_INITIALIZER(shead);
int
ctagcmp(struct ctag *s, struct ctag *t)
{
return strcmp(s->tag, t->tag);
}
/*
* Record the filename that contain tags to be used while loading them
* on first use. If a filename is already recorded, ask user to retain
* already loaded tags (if any) and unload them if user chooses not to.
*/
/* ARGSUSED */
int
tagsvisit(int f, int n)
{
char fname[NFILEN], *bufp, *temp;
struct stat sb;
if (getbufcwd(fname, sizeof(fname)) == FALSE)
fname[0] = '\0';
if (strlcat(fname, DEFAULTFN, sizeof(fname)) >= sizeof(fname)) {
dobeep();
ewprintf("Filename too long");
return (FALSE);
}
bufp = eread("Visit tags table (default %s): ", fname,
NFILEN, EFFILE | EFCR | EFNEW | EFDEF, DEFAULTFN);
if (bufp == NULL)
return (ABORT);
if (stat(bufp, &sb) == -1) {
dobeep();
ewprintf("stat: %s", strerror(errno));
return (FALSE);
} else if (S_ISREG(sb.st_mode) == 0) {
dobeep();
ewprintf("Not a regular file");
return (FALSE);
} else if (access(bufp, R_OK) == -1) {
dobeep();
ewprintf("Cannot access file %s", bufp);
return (FALSE);
}
if (tagsfn == NULL) {
if (bufp[0] == '\0') {
if ((tagsfn = strdup(fname)) == NULL) {
dobeep();
ewprintf("Out of memory");
return (FALSE);
}
} else {
/* bufp points to local variable, so duplicate. */
if ((tagsfn = strdup(bufp)) == NULL) {
dobeep();
ewprintf("Out of memory");
return (FALSE);
}
}
} else {
if ((temp = strdup(bufp)) == NULL) {
dobeep();
ewprintf("Out of memory");
return (FALSE);
}
free(tagsfn);
tagsfn = temp;
if (eyorn("Keep current list of tags table also") == FALSE) {
ewprintf("Starting a new list of tags table");
unloadtags();
}
loaded = FALSE;
}
return (TRUE);
}
/*
* Ask user for a tag while treating word at dot as default. Visit tags
* file if not yet done, load tags and jump to definition of the tag.
*/
int
findtag(int f, int n)
{
char utok[MAX_TOKEN], dtok[MAX_TOKEN];
char *tok, *bufp;
int ret;
if (curtoken(f, n, dtok) == FALSE) {
dtok[0] = '\0';
bufp = eread("Find tag: ", utok, MAX_TOKEN, EFNUL | EFNEW);
} else
bufp = eread("Find tag (default %s): ", utok, MAX_TOKEN,
EFNUL | EFNEW, dtok);
if (bufp == NULL)
return (ABORT);
else if (bufp[0] == '\0')
tok = dtok;
else
tok = utok;
if (tok[0] == '\0') {
dobeep();
ewprintf("There is no default tag");
return (FALSE);
}
if (tagsfn == NULL)
if ((ret = tagsvisit(f, n)) != TRUE)
return (ret);
if (!loaded) {
if (loadtags(tagsfn) == FALSE) {
free(tagsfn);
tagsfn = NULL;
return (FALSE);
}
loaded = TRUE;
}
return pushtag(tok);
}
/*
* Free tags tree.
*/
void
unloadtags(void)
{
struct ctag *var, *nxt;
for (var = RB_MIN(tagtree, &tags); var != NULL; var = nxt) {
nxt = RB_NEXT(tagtree, &tags, var);
RB_REMOVE(tagtree, &tags, var);
/* line parsed with fparseln needs to be freed */
free(var->tag);
free(var);
}
}
/*
* Lookup tag passed in tree and if found, push current location and
* buffername onto stack, load the file with tag definition into a new
* buffer and position dot at the pattern.
*/
/*ARGSUSED */
int
pushtag(char *tok)
{
struct ctag *res;
struct tagpos *s;
char bname[NFILEN];
int doto, dotline;
if ((res = searchtag(tok)) == NULL)
return (FALSE);
doto = curwp->w_doto;
dotline = curwp->w_dotline;
/* record absolute filenames. Fixes issues when mg's cwd is not the
* same as buffer's directory.
*/
if (strlcpy(bname, curbp->b_cwd, sizeof(bname)) >= sizeof(bname)) {
dobeep();
ewprintf("filename too long");
return (FALSE);
}
if (strlcat(bname, curbp->b_bname, sizeof(bname)) >= sizeof(bname)) {
dobeep();
ewprintf("filename too long");
return (FALSE);
}
if (loadbuffer(res->fname) == FALSE)
return (FALSE);
if (searchpat(res->pat) == TRUE) {
if ((s = malloc(sizeof(struct tagpos))) == NULL) {
dobeep();
ewprintf("Out of memory");
return (FALSE);
}
if ((s->bname = strdup(bname)) == NULL) {
dobeep();
ewprintf("Out of memory");
free(s);
return (FALSE);
}
s->doto = doto;
s->dotline = dotline;
SLIST_INSERT_HEAD(&shead, s, entry);
return (TRUE);
} else {
dobeep();
ewprintf("%s: pattern not found", res->tag);
return (FALSE);
}
/* NOTREACHED */
return (FALSE);
}
/*
* If tag stack is not empty pop stack and jump to recorded buffer, dot.
*/
/* ARGSUSED */
int
poptag(int f, int n)
{
struct line *dotp;
struct tagpos *s;
if (SLIST_EMPTY(&shead)) {
dobeep();
ewprintf("No previous location for find-tag invocation");
return (FALSE);
}
s = SLIST_FIRST(&shead);
SLIST_REMOVE_HEAD(&shead, entry);
if (loadbuffer(s->bname) == FALSE)
return (FALSE);
curwp->w_dotline = s->dotline;
curwp->w_doto = s->doto;
/* storing of dotp in tagpos wouldn't work out in cases when
* that buffer is killed by user(dangling pointer). Explicitly
* traverse till dotline for correct handling.
*/
dotp = curwp->w_bufp->b_headp;
while (s->dotline--)
dotp = dotp->l_fp;
curwp->w_dotp = dotp;
free(s->bname);
free(s);
return (TRUE);
}
/*
* Parse the tags file and construct the tags tree. Remove escape
* characters while parsing the file.
*/
int
loadtags(const char *fn)
{
char *l;
FILE *fd;
if ((fd = fopen(fn, "r")) == NULL) {
dobeep();
ewprintf("Unable to open tags file: %s", fn);
return (FALSE);
}
while ((l = fparseln(fd, NULL, NULL, "\\\\\0",
FPARSELN_UNESCCONT | FPARSELN_UNESCREST)) != NULL) {
if (addctag(l) == FALSE) {
fclose(fd);
return (FALSE);
}
}
fclose(fd);
return (TRUE);
}
/*
* Cleanup and destroy tree and stack.
*/
void
closetags(void)
{
struct tagpos *s;
while (!SLIST_EMPTY(&shead)) {
s = SLIST_FIRST(&shead);
SLIST_REMOVE_HEAD(&shead, entry);
free(s->bname);
free(s);
}
unloadtags();
free(tagsfn);
}
/*
* Strip away any special characters in pattern.
* The pattern in ctags isn't a true regular expression. Its of the form
* /^xxx$/ or ?^xxx$? and in some cases the "$" would be missing. Strip
* the leading and trailing special characters so the pattern matching
* would be a simple string compare. Escape character is taken care by
* fparseln.
*/
char *
strip(char *s, size_t len)
{
/* first strip trailing special chars */
s[len - 1] = '\0';
if (s[len - 2] == '$')
s[len - 2] = '\0';
/* then strip leading special chars */
s++;
if (*s == '^')
s++;
return s;
}
/*
* tags line is of the format "<tag>\t<filename>\t<pattern>". Split them
* by replacing '\t' with '\0'. This wouldn't alter the size of malloc'ed
* l, and can be freed during cleanup.
*/
int
addctag(char *l)
{
struct ctag *t;
if ((t = malloc(sizeof(struct ctag))) == NULL) {
dobeep();
ewprintf("Out of memory");
return (FALSE);
}
t->tag = l;
if ((l = strchr(l, '\t')) == NULL)
goto cleanup;
*l++ = '\0';
t->fname = l;
if ((l = strchr(l, '\t')) == NULL)
goto cleanup;
*l++ = '\0';
if (*l == '\0')
goto cleanup;
t->pat = strip(l, strlen(l));
RB_INSERT(tagtree, &tags, t);
return (TRUE);
cleanup:
free(t);
free(l);
return (FALSE);
}
/*
* Search through each line of buffer for pattern.
*/
int
searchpat(char *s_pat)
{
struct line *lp;
int dotline;
size_t plen;
plen = strlen(s_pat);
dotline = 1;
lp = lforw(curbp->b_headp);
while (lp != curbp->b_headp) {
if (ltext(lp) != NULL && plen <= llength(lp) &&
(strncmp(s_pat, ltext(lp), plen) == 0)) {
curwp->w_doto = 0;
curwp->w_dotp = lp;
curwp->w_dotline = dotline;
return (TRUE);
} else {
lp = lforw(lp);
dotline++;
}
}
return (FALSE);
}
/*
* Return TRUE if dot is at beginning of a word or at beginning
* of line, else FALSE.
*/
int
atbow(void)
{
if (curwp->w_doto == 0)
return (TRUE);
if (ISWORD(curwp->w_dotp->l_text[curwp->w_doto]) &&
!ISWORD(curwp->w_dotp->l_text[curwp->w_doto - 1]))
return (TRUE);
return (FALSE);
}
/*
* Extract the word at dot without changing dot position.
*/
int
curtoken(int f, int n, char *token)
{
struct line *odotp;
int odoto, tdoto, odotline, size, r;
char c;
/* Underscore character is to be treated as "inword" while
* processing tokens unlike mg's default word traversal. Save
* and restore its cinfo value so that tag matching works for
* identifier with underscore.
*/
c = cinfo['_'];
cinfo['_'] = _MG_W;
odotp = curwp->w_dotp;
odoto = curwp->w_doto;
odotline = curwp->w_dotline;
/* Move backword unless we are at the beginning of a word or at
* beginning of line.
*/
if (!atbow())
if ((r = backword(f, n)) == FALSE)
goto cleanup;
tdoto = curwp->w_doto;
if ((r = forwword(f, n)) == FALSE)
goto cleanup;
/* strip away leading whitespace if any like emacs. */
while (ltext(curwp->w_dotp) &&
isspace(lgetc(curwp->w_dotp, tdoto)))
tdoto++;
size = curwp->w_doto - tdoto;
if (size <= 0 || size >= MAX_TOKEN ||
ltext(curwp->w_dotp) == NULL) {
r = FALSE;
goto cleanup;
}
strncpy(token, ltext(curwp->w_dotp) + tdoto, size);
token[size] = '\0';
r = TRUE;
cleanup:
cinfo['_'] = c;
curwp->w_dotp = odotp;
curwp->w_doto = odoto;
curwp->w_dotline = odotline;
return (r);
}
/*
* Search tagstree for a given token.
*/
struct ctag *
searchtag(char *tok)
{
struct ctag t, *res;
t.tag = tok;
if ((res = RB_FIND(tagtree, &tags, &t)) == NULL) {
dobeep();
ewprintf("No tag containing %s", tok);
return (NULL);
}
return res;
}
/*
* This is equivalent to filevisit from file.c.
* Look around to see if we can find the file in another buffer; if we
* can't find it, create a new buffer, read in the text, and switch to
* the new buffer. *scratch*, *grep*, *compile* needs to be handled
* differently from other buffers which have "filenames".
*/
int
loadbuffer(char *bname)
{
struct buffer *bufp;
char *adjf;
/* check for special buffers which begin with '*' */
if (bname[0] == '*') {
if ((bufp = bfind(bname, FALSE)) != NULL) {
curbp = bufp;
return (showbuffer(bufp, curwp, WFFULL));
} else {
return (FALSE);
}
} else {
if ((adjf = adjustname(bname, TRUE)) == NULL)
return (FALSE);
if ((bufp = findbuffer(adjf)) == NULL)
return (FALSE);
}
curbp = bufp;
if (showbuffer(bufp, curwp, WFFULL) != TRUE)
return (FALSE);
if (bufp->b_fname[0] == '\0') {
if (readin(adjf) != TRUE) {
killbuffer(bufp);
return (FALSE);
}
}
return (TRUE);
}