entry.c

Exuberant Ctags is a multilanguage reimplementation of the much-underused ctags(1) program and is i

/*
*   $Id: entry.c,v 1.11 2006/05/30 04:37:12 darren Exp $
*
*   Copyright (c) 1996-2002, Darren Hiebert
*
*   This source code is released for free distribution under the terms of the
*   GNU General Public License.
*
*   This module contains functions for creating tag entries.
*/

/*
*   INCLUDE FILES
*/
#include "general.h"  /* must always come first */

#include <string.h>
#include <ctype.h>        /* to define isspace () */
#include <errno.h>

#if defined (HAVE_SYS_TYPES_H)
# include <sys/types.h>	  /* to declare off_t on some hosts */
#endif
#if defined (HAVE_TYPES_H)
# include <types.h>       /* to declare off_t on some hosts */
#endif
#if defined (HAVE_UNISTD_H)
# include <unistd.h>      /* to declare close (), ftruncate (), truncate () */
#endif

/*  These header files provide for the functions necessary to do file
 *  truncation.
 */
#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#endif
#ifdef HAVE_IO_H
# include <io.h>
#endif

#include "debug.h"
#include "ctags.h"
#include "entry.h"
#include "main.h"
#include "options.h"
#include "read.h"
#include "routines.h"
#include "sort.h"
#include "strlist.h"

/*
*   MACROS
*/
#define PSEUDO_TAG_PREFIX       "!_"

#define includeExtensionFlags()         (Option.tagFileFormat > 1)

/*
 *  Portability defines
 */
#if !defined(HAVE_TRUNCATE) && !defined(HAVE_FTRUNCATE) && !defined(HAVE_CHSIZE)
# define USE_REPLACEMENT_TRUNCATE
#endif

/*  Hack for rediculous practice of Microsoft Visual C++.
 */
#if defined (WIN32) && defined (_MSC_VER)
# define chsize         _chsize
# define open           _open
# define close          _close
# define O_RDWR         _O_RDWR
#endif

/*
*   DATA DEFINITIONS
*/

tagFile TagFile = {
    NULL,               /* tag file name */
    NULL,               /* tag file directory (absolute) */
    NULL,               /* file pointer */
    { 0, 0 },           /* numTags */
    { 0, 0, 0 },        /* max */
    { NULL, NULL, 0 },  /* etags */
    NULL                /* vLine */
};

static boolean TagsToStdout = FALSE;

/*
*   FUNCTION PROTOTYPES
*/
#ifdef NEED_PROTO_TRUNCATE
extern int truncate (const char *path, off_t length);
#endif

#ifdef NEED_PROTO_FTRUNCATE
extern int ftruncate (int fd, off_t length);
#endif

/*
*   FUNCTION DEFINITIONS
*/

extern void freeTagFileResources (void)
{
	if (TagFile.directory != NULL)
		eFree (TagFile.directory);
	vStringDelete (TagFile.vLine);
}

extern const char *tagFileName (void)
{
	return TagFile.name;
}

/*
*   Pseudo tag support
*/

static void rememberMaxLengths (const size_t nameLength, const size_t lineLength)
{
	if (nameLength > TagFile.max.tag)
		TagFile.max.tag = nameLength;

	if (lineLength > TagFile.max.line)
		TagFile.max.line = lineLength;
}

static void writePseudoTag (
		const char *const tagName,
		const char *const fileName,
		const char *const pattern)
{
	const int length = fprintf (
			TagFile.fp, "%s%s\t%s\t/%s/\n",
			PSEUDO_TAG_PREFIX, tagName, fileName, pattern);
	++TagFile.numTags.added;
	rememberMaxLengths (strlen (tagName), (size_t) length);
}

static void addPseudoTags (void)
{
	if (! Option.xref)
	{
		char format [11];
		const char *formatComment = "unknown format";

		sprintf (format, "%u", Option.tagFileFormat);

		if (Option.tagFileFormat == 1)
			formatComment = "original ctags format";
		else if (Option.tagFileFormat == 2)
			formatComment =
				"extended format; --format=1 will not append ;\" to lines";

		writePseudoTag ("TAG_FILE_FORMAT", format, formatComment);
		writePseudoTag ("TAG_FILE_SORTED",
			Option.sorted == SO_FOLDSORTED ? "2" :
			(Option.sorted == SO_SORTED ? "1" : "0"),
			"0=unsorted, 1=sorted, 2=foldcase");
		writePseudoTag ("TAG_PROGRAM_AUTHOR",  AUTHOR_NAME,  AUTHOR_EMAIL);
		writePseudoTag ("TAG_PROGRAM_NAME",    PROGRAM_NAME, "");
		writePseudoTag ("TAG_PROGRAM_URL",     PROGRAM_URL,  "official site");
		writePseudoTag ("TAG_PROGRAM_VERSION", PROGRAM_VERSION, "");
	}
}

static void updateSortedFlag (
		const char *const line, FILE *const fp, fpos_t startOfLine)
{
	const char *const tab = strchr (line, '\t');

	if (tab != NULL)
	{
		const long boolOffset = tab - line + 1;  /* where it should be */

		if (line [boolOffset] == '0'  ||  line [boolOffset] == '1')
		{
			fpos_t nextLine;

			if (fgetpos (fp, &nextLine) == -1 || fsetpos (fp, &startOfLine) == -1)
				error (WARNING, "Failed to update 'sorted' pseudo-tag");
			else
			{
				fpos_t flagLocation;
				int c, d;

				do
					c = fgetc (fp);
				while (c != '\t'  &&  c != '\n');
				fgetpos (fp, &flagLocation);
				d = fgetc (fp);
				if (c == '\t'  &&  (d == '0'  ||  d == '1')  &&
					d != (int) Option.sorted)
				{
					fsetpos (fp, &flagLocation);
					fputc (Option.sorted == SO_FOLDSORTED ? '2' :
						(Option.sorted == SO_SORTED ? '1' : '0'), fp);
				}
				fsetpos (fp, &nextLine);
			}
		}
	}
}

/*  Look through all line beginning with "!_TAG_FILE", and update those which
 *  require it.
 */
static long unsigned int updatePseudoTags (FILE *const fp)
{
	enum { maxEntryLength = 20 };
	char entry [maxEntryLength + 1];
	unsigned long linesRead = 0;
	fpos_t startOfLine;
	size_t entryLength;
	const char *line;

	sprintf (entry, "%sTAG_FILE", PSEUDO_TAG_PREFIX);
	entryLength = strlen (entry);
	Assert (entryLength < maxEntryLength);

	fgetpos (fp, &startOfLine);
	line = readLine (TagFile.vLine, fp);
	while (line != NULL  &&  line [0] == entry [0])
	{
		++linesRead;
		if (strncmp (line, entry, entryLength) == 0)
		{
			char tab, classType [16];

			if (sscanf (line + entryLength, "%15s%c", classType, &tab) == 2  &&
				tab == '\t')
			{
				if (strcmp (classType, "_SORTED") == 0)
					updateSortedFlag (line, fp, startOfLine);
			}
			fgetpos (fp, &startOfLine);
		}
		line = readLine (TagFile.vLine, fp);
	}
	while (line != NULL)  /* skip to end of file */
	{
		++linesRead;
		line = readLine (TagFile.vLine, fp);
	}
	return linesRead;
}

/*
 *  Tag file management
 */

static boolean isValidTagAddress (const char *const excmd)
{
	boolean isValid = FALSE;

	if (strchr ("/?", excmd [0]) != NULL)
		isValid = TRUE;
	else
	{
		char *address = xMalloc (strlen (excmd) + 1, char);
		if (sscanf (excmd, "%[^;\n]", address) == 1  &&
			strspn (address,"0123456789") == strlen (address))
				isValid = TRUE;
		eFree (address);
	}
	return isValid;
}

static boolean isCtagsLine (const char *const line)
{
	enum fieldList { TAG, TAB1, SRC_FILE, TAB2, EXCMD, NUM_FIELDS };
	boolean ok = FALSE;  /* we assume not unless confirmed */
	const size_t fieldLength = strlen (line) + 1;
	char *const fields = xMalloc (NUM_FIELDS * fieldLength, char);

	if (fields == NULL)
		error (FATAL, "Cannot analyze tag file");
	else
	{
#define field(x)		(fields + ((size_t) (x) * fieldLength))

		const int numFields = sscanf (
			line, "%[^\t]%[\t]%[^\t]%[\t]%[^\r\n]",
			field (TAG), field (TAB1), field (SRC_FILE),
			field (TAB2), field (EXCMD));

		/*  There must be exactly five fields: two tab fields containing
		 *  exactly one tab each, the tag must not begin with "#", and the
		 *  file name should not end with ";", and the excmd must be
		 *  accceptable.
		 *
		 *  These conditions will reject tag-looking lines like:
		 *      int a;        <C-comment>
		 *      #define LABEL <C-comment>
		 */
		if (numFields == NUM_FIELDS   &&
			strlen (field (TAB1)) == 1  &&
			strlen (field (TAB2)) == 1  &&
			field (TAG) [0] != '#'      &&
			field (SRC_FILE) [strlen (field (SRC_FILE)) - 1] != ';'  &&
			isValidTagAddress (field (EXCMD)))
				ok = TRUE;

		eFree (fields);
	}
	return ok;
}

static boolean isEtagsLine (const char *const line)
{
	boolean result = FALSE;
	if (line [0] == '\f')
		result = (boolean) (line [1] == '\n'  ||  line [1] == '\r');
	return result;
}

static boolean isTagFile (const char *const filename)
{
	boolean ok = FALSE;  /* we assume not unless confirmed */
	FILE *const fp = fopen (filename, "rb");

	if (fp == NULL  &&  errno == ENOENT)
		ok = TRUE;
	else if (fp != NULL)
	{
		const char *line = readLine (TagFile.vLine, fp);

		if (line == NULL)
			ok = TRUE;
		else
			ok = (boolean) (isCtagsLine (line) || isEtagsLine (line));
		fclose (fp);
	}
	return ok;
}

extern void copyBytes (FILE* const fromFp, FILE* const toFp, const long size)
{
	enum { BufferSize = 1000 };
	long toRead, numRead;
	char* buffer = xMalloc (BufferSize, char);
	long remaining = size;
	do
	{
		toRead = (0 < remaining && remaining < BufferSize) ?
					remaining : (long) BufferSize;
		numRead = fread (buffer, (size_t) 1, (size_t) toRead, fromFp);
		if (fwrite (buffer, (size_t)1, (size_t)numRead, toFp) < (size_t)numRead)
			error (FATAL | PERROR, "cannot complete write");
		if (remaining > 0)
			remaining -= numRead;
	} while (numRead == toRead  &&  remaining != 0);
	eFree (buffer);
}

extern void copyFile (const char *const from, const char *const to, const long size)
{
	FILE* const fromFp = fopen (from, "rb");
	if (fromFp == NULL)
		error (FATAL | PERROR, "cannot open file to copy");
	else
	{
		FILE* const toFp = fopen (to, "wb");
		if (toFp == NULL)
			error (FATAL | PERROR, "cannot open copy destination");
		else
		{
			copyBytes (fromFp, toFp, size);
			fclose (toFp);
		}
		fclose (fromFp);
	}
}

extern void openTagFile (void)
{
	setDefaultTagFileName ();
	TagsToStdout = isDestinationStdout ();

	if (TagFile.vLine == NULL)
		TagFile.vLine = vStringNew ();

	/*  Open the tags file.
	 */
	if (TagsToStdout)
		TagFile.fp = tempFile ("w", &TagFile.name);
	else
	{
		boolean fileExists;

		setDefaultTagFileName ();
		TagFile.name = eStrdup (Option.tagFileName);
		fileExists = doesFileExist (TagFile.name);
		if (fileExists  &&  ! isTagFile (TagFile.name))
			error (FATAL,
			  "\"%s\" doesn't look like a tag file; I refuse to overwrite it.",
				  TagFile.name);

		if (Option.etags)
		{
			if (Option.append  &&  fileExists)
				TagFile.fp = fopen (TagFile.name, "a+b");
			else
				TagFile.fp = fopen (TagFile.name, "w+b");
		}
		else
		{
			if (Option.append  &&  fileExists)
			{
				TagFile.fp = fopen (TagFile.name, "r+");
				if (TagFile.fp != NULL)
				{
					TagFile.numTags.prev = updatePseudoTags (TagFile.fp);
					fclose (TagFile.fp);
					TagFile.fp = fopen (TagFile.name, "a+");
				}
			}
			else
			{
				TagFile.fp = fopen (TagFile.name, "w");
				if (TagFile.fp != NULL)
					addPseudoTags ();