X-Git-Url: https://pd.if.org/git/?p=pd_readline;a=blobdiff_plain;f=mg%2Ftags.c;fp=mg%2Ftags.c;h=92d1425e79efee5b563921b6348fe3144961d8dd;hp=0000000000000000000000000000000000000000;hb=a9843085ec916c175bd245a8398f30e6cc03f984;hpb=26fe4e09c6c3c250334fdeed60ce3061febecde2

diff --git a/mg/tags.c b/mg/tags.c
new file mode 100644
index 0000000..92d1425
--- /dev/null
+++ b/mg/tags.c
@@ -0,0 +1,533 @@
+/*	$OpenBSD: tags.c,v 1.5 2012/07/02 08:08:31 lum Exp $	*/
+
+/*
+ * This file is in the public domain.
+ *
+ * Author: Sunil Nimmagadda <sunil@sunilnimmagadda.com>
+ */
+
+#include <sys/queue.h>
+#include <sys/stat.h>
+#include <sys/tree.h>
+#include <sys/types.h>
+
+#include <ctype.h>
+#include <err.h>
+#include <stdlib.h>
+#include <string.h>
+#include <util.h>
+
+#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);
+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)) {
+		ewprintf("Filename too long");
+		return (FALSE);
+	}
+	
+	bufp = eread("visit tags table (default %s): ", fname,
+	    NFILEN, EFFILE | EFCR | EFNEW | EFDEF, DEFAULTFN);
+
+	if (stat(bufp, &sb) == -1) {
+		ewprintf("stat: %s", strerror(errno));
+		return (FALSE);
+	} else if (S_ISREG(sb.st_mode) == 0) {
+		ewprintf("Not a regular file");
+		return (FALSE);
+	} else if (access(bufp, R_OK) == -1) {
+		ewprintf("Cannot access file %s", bufp);
+		return (FALSE);
+	}
+	
+	if (tagsfn == NULL) {
+		if (bufp == NULL)
+			return (ABORT);
+		else if (bufp[0] == '\0') {
+			if ((tagsfn = strdup(fname)) == NULL) {
+				ewprintf("Out of memory");
+				return (FALSE);
+			}
+		} else {
+			/* bufp points to local variable, so duplicate. */
+			if ((tagsfn = strdup(bufp)) == NULL) {
+				ewprintf("Out of memory");
+				return (FALSE);
+			}
+		}
+	} else {
+		if ((temp = strdup(bufp)) == NULL) {
+			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)
+		return (FALSE);
+	
+	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') {
+		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)) {
+		    ewprintf("filename too long");
+		    return (FALSE);
+	}
+	if (strlcat(bname, curbp->b_bname, sizeof(bname)) >= sizeof(bname)) {
+		    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) {
+			ewprintf("Out of memory");
+			return (FALSE);
+		}
+		if ((s->bname = strdup(bname)) == NULL) {
+			ewprintf("Out of memory");
+			return (FALSE);
+		}
+		s->doto = doto;
+		s->dotline = dotline;
+		SLIST_INSERT_HEAD(&shead, s, entry);
+		return (TRUE);
+	} else {
+		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)) {
+		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) {
+		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) {
+		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 (TRUE);
+}
+
+/*
+ * Search through each line of buffer for pattern.
+ */
+int
+searchpat(char *pat)
+{
+	struct line *lp;
+	int dotline;
+	size_t plen;
+
+	plen = strlen(pat);
+	dotline = 1;
+	lp = lforw(curbp->b_headp);
+	while (lp != curbp->b_headp) {
+		if (ltext(lp) != NULL && plen <= llength(lp) &&
+		    (strncmp(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 it's 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(curwp->w_dotp->l_text[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) {
+		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);
+}