entry.c

/*
*
*   Copyright (c) 1996-2001, 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>
#include <glib.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 "ctags.h"
#include "entry.h"
#include "main.h"
#include "options.h"
#include "read.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)
{
    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 ? "1":"0",
		       "0=unsorted, 1=sorted");
	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 ? '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 { maxClassLength = 20 };
    char class [maxClassLength + 1];
    unsigned long linesRead = 0;
    fpos_t startOfLine;
    size_t classLength;
    const char *line;

    sprintf (class, "%sTAG_FILE", PSEUDO_TAG_PREFIX);
    classLength = strlen (class);
    Assert (classLength < maxClassLength);

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

	    if (sscanf (line + classLength, "%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 : 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 ();
	    }
	}
	if (TagFile.fp == NULL)
	{
	    error (FATAL | PERROR, "cannot open tag file");
	    exit (1);
	}
    }
    if (TagsToStdout)
	TagFile.directory = eStrdup (CurrentDirectory);
    else
	TagFile.directory = absoluteDirname (TagFile.name);
}

#ifdef USE_REPLACEMENT_TRUNCATE

/*  Replacement for missing library function.
 */
static int replacementTruncate (const char *const name, const long size)
{
    char *tempName = NULL;
    FILE *fp = tempFile ("w", &tempName);
    fclose (fp);
    copyFile (name, tempName, size);
    copyFile (tempName, name, WHOLE_FILE);
    remove (tempName);
    eFree (tempName);

    return 0;
}

#endif

static void sortTagFile (void)
{
    if (TagFile.numTags.added > 0L)
    {
	if (Option.sorted)
	{
	    verbose ("sorting tag file\n");
#ifdef EXTERNAL_SORT
	    externalSortTags (TagsToStdout);
#else
	    internalSortTags (TagsToStdout);
#endif
	}
	else if (TagsToStdout)
	    catFile (tagFileName ());
    }
    if (TagsToStdout)
	remove (tagFileName ());		/* remove temporary file */
}

static void resizeTagFile (const long newSize)
{
    int result;

#ifdef USE_REPLACEMENT_TRUNCATE
    result = replacementTruncate (TagFile.name, newSize);
#else
# ifdef HAVE_TRUNCATE
    result = truncate (TagFile.name, (off_t) newSize);
# else
    const int fd = open (TagFile.name, O_RDWR);

    if (fd == -1)
	result = -1;
    else
    {
#  ifdef HAVE_FTRUNCATE
	result = ftruncate (fd, (off_t) newSize);
#  else
#   ifdef HAVE_CHSIZE
	result = chsize (fd, newSize);
#   endif
#  endif
	close (fd);
    }
# endif
#endif
    if (result == -1)
	fprintf (errout, "Cannot shorten tag file: errno = %d\n", errno);
}

static void writeEtagsIncludes (FILE *const fp)
{
    if (Option.etagsInclude)
    {
	unsigned int i;
	for (i = 0  ;  i < stringListCount (Option.etagsInclude)  ;  ++i)
	{
	    vString *item = stringListItem (Option.etagsInclude, i);
	    fprintf (fp, "\f\n%s,include\n", vStringValue (item));
	}
    }
}

extern void closeTagFile (const boolean resize)
{
    long desiredSize, size;

    if (Option.etags)
	writeEtagsIncludes (TagFile.fp);
    desiredSize = ftell (TagFile.fp);
    fseek (TagFile.fp, 0L, SEEK_END);
    size = ftell (TagFile.fp);
    fclose (TagFile.fp);
    if (resize  &&  desiredSize < size)
    {
	DebugStatement (
	    debugPrintf (DEBUG_STATUS, "shrinking %s from %ld to %ld bytes\n",
			TagFile.name, size, desiredSize); )
	resizeTagFile (desiredSize);
    }
    sortTagFile ();
    eFree (TagFile.name);
    TagFile.name = NULL;
}

extern void beginEtagsFile (void)
{
    TagFile.etags.fp = tempFile ("w+b", &TagFile.etags.name);
    TagFile.etags.byteCount = 0;
}

extern void endEtagsFile (const char *const name)
{
    const char *line;

    fprintf (TagFile.fp, "\f\n%s,%ld\n", name, (long) TagFile.etags.byteCount);
    if (TagFile.etags.fp != NULL)
    {
	rewind (TagFile.etags.fp);
	while ((line = readLine (TagFile.vLine, TagFile.etags.fp)) != NULL)
	    fputs (line, TagFile.fp);
	fclose (TagFile.etags.fp);
	remove (TagFile.etags.name);
	eFree (TagFile.etags.name);
	TagFile.etags.fp = NULL;
	TagFile.etags.name = NULL;
    }
}

/*
 *  Tag entry management
 */

/*  This function copies the current line out to a specified file. It has no
 *  effect on the fileGetc () function.  During copying, any '\' characters
 *  are doubled and a leading '^' or trailing '$' is also quoted. End of line
 *  characters (line feed or carriage return) are dropped.
 */
static size_t writeSourceLine (FILE *const fp, const char *const line)
{
    size_t length = 0;
    const char *p;

    /*	Write everything up to, but not including, a line end character.
     */
    for (p = line  ;  *p != '\0'  ;  ++p)
    {
	const int next = *(p + 1);
	const int c = *p;

	if (c == CRETURN  ||  c == NEWLINE)
	    break;

	/*  If character is '\', or a terminal '$', then quote it.
	 */
	if (c == BACKSLASH  ||  c == (Option.backward ? '?' : '/')  ||
	    (c == '$'  &&  (next == NEWLINE  ||  next == CRETURN)))
	{
	    putc (BACKSLASH, fp);
	    ++length;
	}
	putc (c, fp);
	++length;
    }
    return length;
}

/*  Writes "line", stripping leading and duplicate white space.
 */
static size_t writeCompactSourceLine (FILE *const fp, const char *const line)
{
    boolean lineStarted = FALSE;
    size_t  length = 0;
    const char *p;
    int c;

    /*	Write everything up to, but not including, the newline.
     */
    for (p = line, c = *p  ;  c != NEWLINE  &&  c != '\0'  ;  c = *++p)
    {
	if (lineStarted  || ! isspace (c))	/* ignore leading spaces */
	{
	    lineStarted = TRUE;
	    if (isspace (c))
	    {
		int next;

		/*  Consume repeating white space.
		 */
		while (next = *(p+1) , isspace (next)  &&  next != NEWLINE)
		    ++p;
		c = ' ';	/* force space character for any white space */
	    }
	    if (c != CRETURN  ||  *(p + 1) != NEWLINE)
	    {
		putc (c, fp);
		++length;
	    }
	}
    }
    return length;
}

static int writeXrefEntry (const tagEntryInfo *const tag)
{
    const char *const line =
			readSourceLine (TagFile.vLine, tag->filePosition, NULL);
    int length = fprintf (TagFile.fp, "%-20s %-10s %4lu  %-14s ", tag->name,
			 tag->kindName, tag->lineNumber, tag->sourceFileName);

    length += writeCompactSourceLine (TagFile.fp, line);
    putc (NEWLINE, TagFile.fp);
    ++length;

    return length;
}

/*  Truncates the text line containing the tag at the character following the
 *  tag, providing a character which designates the end of the tag.
 */
static void truncateTagLine (char *const line, const char *const token,
			     const boolean discardNewline)
{
    char *p = strstr (line, token);

    if (p != NULL)
    {
	p += strlen (token);
	if (*p != '\0'  &&  ! (*p == '\n'  &&  discardNewline))
	    ++p;		/* skip past character terminating character */
	*p = '\0';
    }
}

static int writeEtagsEntry (const tagEntryInfo *const tag)
{
    int length;

    if (tag->isFileEntry)
	length = fprintf (TagFile.etags.fp, "\177%s\001%lu,0\n",
			 tag->name, tag->lineNumber);
    else
    {
	long seekValue;
	char *const line =
		readSourceLine (TagFile.vLine, tag->filePosition, &seekValue);

	if (tag->truncateLine)
	    truncateTagLine (line, tag->name, TRUE);
	else
	    line [strlen (line) - 1] = '\0';

	length = fprintf (TagFile.etags.fp, "%s\177%s\001%lu,%ld\n", line,
			 tag->name, tag->lineNumber, seekValue);
    }
    TagFile.etags.byteCount += length;

    return length;
}

static int addExtensionFields (const tagEntryInfo *const tag)
{
    const char* const kindKey = Option.extensionFields.kindKey ? "kind:" : "";
    int length = fprintf (TagFile.fp, ";\"");

    if (tag->kindName != NULL && (
	 Option.extensionFields.kindLong  ||  tag->kind == '\0'))
	length += fprintf (TagFile.fp, "\t%s%s", kindKey, tag->kindName);
    else if (tag->kind != '\0'  && (
	 ! Option.extensionFields.kindLong  ||  tag->kindName == NULL))
	length += fprintf (TagFile.fp, "\t%s%c", kindKey, tag->kind);

    if (Option.extensionFields.lineNumber)
	length += fprintf (TagFile.fp, "\tline:%ld", tag->lineNumber);

    if (Option.extensionFields.language  &&  tag->language != NULL)
	length += fprintf (TagFile.fp, "\tlanguage:%s", tag->language);

    if (Option.extensionFields.scope  &&
	    tag->extensionFields.scope [0] != NULL  &&
	    tag->extensionFields.scope [1] != NULL)
	length += fprintf (TagFile.fp, "\t%s:%s",
			   tag->extensionFields.scope [0],
			   tag->extensionFields.scope [1]);

    if (Option.extensionFields.fileScope  &&  tag->isFileScope)
	length += fprintf (TagFile.fp, "\tfile:");

    if (Option.extensionFields.inheritance  &&
	    tag->extensionFields.inheritance != NULL)
	length += fprintf (TagFile.fp, "\tinherits:%s",
			   tag->extensionFields.inheritance);

    if (Option.extensionFields.access  &&  tag->extensionFields.access != NULL)
	length += fprintf (TagFile.fp, "\taccess:%s",
			   tag->extensionFields.access);

    if (Option.extensionFields.implementation  &&
	    tag->extensionFields.implementation != NULL)
	length += fprintf (TagFile.fp, "\timplementation:%s",
			   tag->extensionFields.implementation);
	
	if ((Option.extensionFields.argList) &&
		(tag->extensionFields.arglist != NULL))
		length += fprintf(TagFile.fp, "\targlist:%s", tag->extensionFields.arglist);

    return length;
}

static int writePatternEntry (const tagEntryInfo *const tag)
{
    char *const line = readSourceLine (TagFile.vLine, tag->filePosition, NULL);
    const int searchChar = Option.backward ? '?' : '/';
    boolean newlineTerminated;
    int length = 0;

    if (tag->truncateLine)
	truncateTagLine (line, tag->name, FALSE);
    newlineTerminated = (boolean) (line [strlen (line) - 1] == '\n');

    length += fprintf (TagFile.fp, "%c^", searchChar);
    length += writeSourceLine (TagFile.fp, line);
    length += fprintf (TagFile.fp, "%s%c", newlineTerminated ? "$":"",
		      searchChar);

    return length;
}


static int writeLineNumberEntry (const tagEntryInfo *const tag)
{
    return fprintf (TagFile.fp, "%lu", tag->lineNumber);
}

static int writeCtagsEntry (const tagEntryInfo *const tag)
{
    int length = fprintf (TagFile.fp, "%s\t%s\t",
			  tag->name, tag->sourceFileName);

    if (tag->lineNumberEntry)
	length += writeLineNumberEntry (tag);
    else
	length += writePatternEntry (tag);

    if (includeExtensionFlags ())
	length += addExtensionFields (tag);

    length += fprintf (TagFile.fp, "\n");

    return length;
}

extern void makeTagEntry (const tagEntryInfo *const tag)
{
    Assert (tag->name != NULL);
    if (tag->name [0] == '\0')
	error (WARNING, "ignoring null tag in %s", vStringValue (File.name));
    else
    {
	int length = 0;

	DebugStatement ( debugEntry (tag); )
	if (NULL != TagEntryFunction)
		length = TagEntryFunction(tag);
	else if (Option.xref)
	{
	    if (! tag->isFileEntry)
		length = writeXrefEntry (tag);
	}
	else if (Option.etags)
	    length = writeEtagsEntry (tag);
	else
	    length = writeCtagsEntry (tag);

	++TagFile.numTags.added;
	rememberMaxLengths (strlen (tag->name), (size_t) length);
    }
}

extern void initTagEntry (tagEntryInfo *const e, const char *const name)
{
    Assert (File.source.name != NULL);
    memset (e, 0, sizeof (tagEntryInfo));
    e->lineNumberEntry	= (boolean) (Option.locate == EX_LINENUM);
    e->lineNumber	= getSourceLineNumber ();
    e->language		= getSourceLanguageName ();
    e->filePosition	= getInputFilePosition ();
    e->sourceFileName	= getSourceFileTagPath ();
    e->name		= name;
}

/* vi:set tabstop=8 shiftwidth=4: */