/*
*   Copyright (c) 1996-2002, Darren Hiebert
*
*   This source code is released for free distribution under the terms of the
*   GNU General Public License version 2 or (at your option) any later version.
*
*   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 <stdint.h>
#include <limits.h>  /* to define INT_MAX */

#include "debug.h"
#include "entry_p.h"
#include "field.h"
#include "fmt_p.h"
#include "kind.h"
#include "nestlevel.h"
#include "options_p.h"
#include "ptag_p.h"
#include "rbtree.h"
#include "read.h"
#include "read_p.h"
#include "routines.h"
#include "routines_p.h"
#include "parse_p.h"
#include "ptrarray.h"
#include "sort_p.h"
#include "strlist.h"
#include "subparser_p.h"
#include "trashbox.h"
#include "writer_p.h"
#include "xtag_p.h"

/*
*   MACROS
*/

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

/*  Hack for ridiculous 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


/*  Maintains the state of the tag file.
 */
typedef struct eTagFile {
	char *name;
	char *directory;
	MIO *mio;
	struct sNumTags { unsigned long added, prev; } numTags;
	struct sMax { size_t line, tag; } max;
	vString *vLine;

	int cork;
	unsigned int corkFlags;
	ptrArray *corkQueue;

	bool patternCacheValid;
} tagFile;

typedef struct sTagEntryInfoX  {
	tagEntryInfo slot;
	int corkIndex;
	struct rb_root symtab;
	struct rb_node symnode;
} tagEntryInfoX;

/*
*   DATA DEFINITIONS
*/

static tagFile TagFile = {
    NULL,               /* tag file name */
    NULL,               /* tag file directory (absolute) */
    NULL,               /* file pointer */
    { 0, 0 },           /* numTags */
    { 0, 0 },        /* max */
    NULL,                /* vLine */
    .cork = false,
    .corkQueue = NULL,
    .patternCacheValid = false,
};

static bool 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
*/

extern void abort_if_ferror(MIO *const mio)
{
	if (mio != NULL && mio_error (mio))
		error (FATAL | PERROR, "cannot write tag file");
}

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 addCommonPseudoTags (void)
{
	for (int i = 0; i < PTAG_COUNT; i++)
	{
		if (isPtagCommonInParsers (i))
			makePtagIfEnabled (i, LANG_IGNORE, &Option);
	}
}

extern void makeFileTag (const char *const fileName)
{
	tagEntryInfo tag;

	if (!isXtagEnabled(XTAG_FILE_NAMES))
		return;

	initTagEntry (&tag, baseFilename (fileName), KIND_FILE_INDEX);

	tag.isFileEntry     = true;
	tag.lineNumberEntry = true;
	markTagExtraBit (&tag, XTAG_FILE_NAMES);

	tag.lineNumber = 1;
	if (isFieldEnabled (FIELD_END_LINE))
	{
		/* isFieldEnabled is called again in the rendering
		   stage. However, it is called here for avoiding
		   unnecessary read line loop. */
		while (readLineFromInputFile () != NULL)
			; /* Do nothing */
		tag.extensionFields.endLine = getInputLineNumber ();
	}

	if (isFieldEnabled (FIELD_EPOCH))
		tag.extensionFields.epoch = getInputFileMtime ();

	makeTagEntry (&tag);
}

static void updateSortedFlag (
		const char *const line, MIO *const mio, MIOPos 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')
		{
			MIOPos nextLine;

			if (mio_getpos (mio, &nextLine) == -1 || mio_setpos (mio, &startOfLine) == -1)
				error (WARNING, "Failed to update 'sorted' pseudo-tag");
			else
			{
				MIOPos flagLocation;
				int c, d;

				do
					c = mio_getc (mio);
				while (c != '\t'  &&  c != '\n');
				mio_getpos (mio, &flagLocation);
				d = mio_getc (mio);
				if (c == '\t'  &&  (d == '0'  ||  d == '1')  &&
					d != (int) Option.sorted)
				{
					mio_setpos (mio, &flagLocation);
					mio_putc (mio, Option.sorted == SO_FOLDSORTED ? '2' :
						(Option.sorted == SO_SORTED ? '1' : '0'));
				}
				mio_setpos (mio, &nextLine);
			}
		}
	}
}

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

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

	mio_getpos (mio, &startOfLine);
	line = readLineRaw (TagFile.vLine, mio);
	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, mio, startOfLine);
			}
			mio_getpos (mio, &startOfLine);
		}
		line = readLineRaw (TagFile.vLine, mio);
	}
	while (line != NULL)  /* skip to end of file */
	{
		++linesRead;
		line = readLineRaw (TagFile.vLine, mio);
	}
	return linesRead;
}

/*
 *  Tag file management
 */

static bool isValidTagAddress (const char *const excmd)
{
	bool 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 bool isCtagsLine (const char *const line)
{
	enum fieldList { TAG, TAB1, SRC_FILE, TAB2, EXCMD, NUM_FIELDS };
	bool 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
		 *  acceptable.
		 *
		 *  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 bool isEtagsLine (const char *const line)
{
	bool result = false;
	if (line [0] == '\f')
		result = (bool) (line [1] == '\n'  ||  line [1] == '\r');
	return result;
}

static bool isTagFile (const char *const filename)
{
	bool ok = false;  /* we assume not unless confirmed */
	MIO *const mio = mio_new_file (filename, "rb");

	if (mio == NULL  &&  errno == ENOENT)
		ok = true;
	else if (mio != NULL)
	{
		const char *line = readLineRaw (TagFile.vLine, mio);

		if (line == NULL)
			ok = true;
		else
			ok = (bool) (isCtagsLine (line) || isEtagsLine (line));
		mio_unref (mio);
	}
	return ok;
}

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

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

	/*  Open the tags file.
	 */
	if (TagsToStdout)
	{
		if (Option.interactive == INTERACTIVE_SANDBOX)
		{
			TagFile.mio = mio_new_memory (NULL, 0, eRealloc, eFreeNoNullCheck);
			TagFile.name = NULL;
		}
		else
			TagFile.mio = tempFile ("w+", &TagFile.name);
		if (isXtagEnabled (XTAG_PSEUDO_TAGS))
			addCommonPseudoTags ();
	}
	else
	{
		bool fileExists;

		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.mio = mio_new_file (TagFile.name, "a+b");
			else
				TagFile.mio = mio_new_file (TagFile.name, "w+b");
		}
		else
		{
			if (Option.append  &&  fileExists)
			{
				TagFile.mio = mio_new_file (TagFile.name, "r+");
				if (TagFile.mio != NULL)
				{
					TagFile.numTags.prev = updatePseudoTags (TagFile.mio);
					mio_unref (TagFile.mio);
					TagFile.mio = mio_new_file (TagFile.name, "a+");
				}
			}
			else
			{
				TagFile.mio = mio_new_file (TagFile.name, "w");
				if (TagFile.mio != NULL && isXtagEnabled (XTAG_PSEUDO_TAGS))
					addCommonPseudoTags ();
			}
		}
		if (TagFile.mio == NULL)
			error (FATAL | PERROR, "cannot open tag file");
	}

	if (TagFile.directory == NULL)
	{
		if (TagsToStdout)
			TagFile.directory = eStrdup (CurrentDirectory);
		else
			TagFile.directory = absoluteDirname (TagFile.name);
	}
}

#ifdef USE_REPLACEMENT_TRUNCATE

static void copyBytes (MIO* const fromMio, MIO* const toMio, 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 = mio_read (fromMio, buffer, (size_t) 1, (size_t) toRead);
		if (mio_write (toMio, buffer, (size_t)1, (size_t)numRead) < (size_t)numRead)
			error (FATAL | PERROR, "cannot complete write");
		if (remaining > 0)
			remaining -= numRead;
	} while (numRead == toRead  &&  remaining != 0);
	eFree (buffer);
}

static void copyFile (const char *const from, const char *const to, const long size)
{
	MIO* const fromMio = mio_new_file (from, "rb");
	if (fromMio == NULL)
		error (FATAL | PERROR, "cannot open file to copy");
	else
	{
		MIO* const toMio = mio_new_file (to, "wb");
		if (toMio == NULL)
			error (FATAL | PERROR, "cannot open copy destination");
		else
		{
			copyBytes (fromMio, toMio, size);
			mio_unref (toMio);
		}
		mio_unref (fromMio);
	}
}

/*  Replacement for missing library function.
 */
static int replacementTruncate (const char *const name, const long size)
{
#define WHOLE_FILE  -1L
	char *tempName = NULL;
	MIO *mio = tempFile ("w", &tempName);
	mio_unref (mio);
	copyFile (name, tempName, size);
	copyFile (tempName, name, WHOLE_FILE);
	remove (tempName);
	eFree (tempName);

	return 0;
}

#endif

#ifndef EXTERNAL_SORT
static void internalSortTagFile (void)
{
	MIO *mio;

	/*  Open/Prepare the tag file and place its lines into allocated buffers.
	 */
	if (TagsToStdout)
	{
		mio = TagFile.mio;
		mio_seek (mio, 0, SEEK_SET);
	}
	else
	{
		mio = mio_new_file (tagFileName (), "r");
		if (mio == NULL)
			failedSort (mio, NULL);
	}

	internalSortTags (TagsToStdout,
			  mio,
			  TagFile.numTags.added + TagFile.numTags.prev);

	if (! TagsToStdout)
		mio_unref (mio);
}
#endif

static void sortTagFile (void)
{
	if (TagFile.numTags.added > 0L)
	{
		if (Option.sorted != SO_UNSORTED)
		{
			verbose ("sorting tag file\n");
#ifdef EXTERNAL_SORT
			externalSortTags (TagsToStdout, TagFile.mio);
#else
			internalSortTagFile ();
#endif
		}
		else if (TagsToStdout)
			catFile (TagFile.mio);
	}
}

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

	if (!TagFile.name)
	{
		mio_try_resize (TagFile.mio, newSize);
		return;
	}

#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 (stderr, "Cannot shorten tag file: errno = %d\n", errno);
}

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

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

	if (Option.etags)
		writeEtagsIncludes (TagFile.mio);
	mio_flush (TagFile.mio);

	abort_if_ferror (TagFile.mio);
	desiredSize = mio_tell (TagFile.mio);
	mio_seek (TagFile.mio, 0L, SEEK_END);
	size = mio_tell (TagFile.mio);
	if (! TagsToStdout)
		/* The tag file should be closed before resizing. */
		if (mio_unref (TagFile.mio) != 0)
			error (FATAL | PERROR, "cannot close tag file");

	if (resize  &&  desiredSize < size)
	{
		DebugStatement (
			debugPrintf (DEBUG_STATUS, "shrinking %s from %ld to %ld bytes\n",
				TagFile.name? TagFile.name: "<mio>", size, desiredSize); )
		resizeTagFile (desiredSize);
	}
	sortTagFile ();
	if (TagsToStdout)
	{
		if (mio_unref (TagFile.mio) != 0)
			error (FATAL | PERROR, "cannot close tag file");
		if (TagFile.name)
			remove (TagFile.name);  /* remove temporary file */
	}

	TagFile.mio = NULL;
	if (TagFile.name)
		eFree (TagFile.name);
	TagFile.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 appendInputLine (int putc_func (char , void *), const char *const line,
							   unsigned int patternLengthLimit,
							   void * data, bool *omitted)
{
	size_t length = 0;
	const char *p;
	int extraLength = 0;

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

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

		if (patternLengthLimit != 0 && length >= patternLengthLimit &&
			/* Do not cut inside a multi-byte UTF-8 character, but safe-guard it not to
			 * allow more than one extra valid UTF-8 character in case it's not actually
			 * UTF-8.  To do that, limit to an extra 3 UTF-8 sub-bytes (0b10xxxxxx). */
			((((unsigned char) c) & 0xc0) != 0x80 || ++extraLength > 3))
		{
			*omitted = true;
			break;
		}
		/*  If character is '\', or a terminal '$', then quote it.
		 */
		if (c == BACKSLASH  ||  c == (Option.backward ? '?' : '/')  ||
			(c == '$'  &&  (next == NEWLINE  ||  next == CRETURN)))
		{
			putc_func (BACKSLASH, data);
			++length;
		}
		putc_func (c, data);
		++length;
	}

	return length;
}

static int vstring_putc (char c, void *data)
{
	vString *str = data;
	vStringPut (str, c);
	return 1;
}

static int vstring_puts (const char* s, void *data)
{
	vString *str = data;
	size_t len = vStringLength (str);
	vStringCatS (str, s);
	return (int) (vStringLength (str) - len);
}

#ifdef DEBUG
static bool isPosSet(MIOPos pos)
{
	char * p = (char *)&pos;
	bool r = false;
	unsigned int i;

	for (i = 0; i < sizeof(pos); i++)
		r |= p[i];
	return r;
}
#endif

extern char *readLineFromBypassForTag (vString *const vLine, const tagEntryInfo *const tag,
				   long *const pSeekValue)
{
	Assert (isPosSet (tag->filePosition) || (tag->pattern == NULL));
	return readLineFromBypass (vLine, tag->filePosition, pSeekValue);
}

/*  Truncates the text line containing the tag at the character following the
 *  tag, providing a character which designates the end of the tag.
 *  Returns the length of the truncated line (or 0 if it doesn't truncate).
 */
extern size_t truncateTagLineAfterTag (
		char *const line, const char *const token, const bool discardNewline)
{
	size_t len = 0;
	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';
		len = p - line;
	}

	return len;
}

static char* getFullQualifiedScopeNameFromCorkQueue (const tagEntryInfo * inner_scope)
{

	int kindIndex = KIND_GHOST_INDEX;
	langType lang;
	const tagEntryInfo *scope = inner_scope;
	const tagEntryInfo *root_scope = NULL;
	stringList *queue = stringListNew ();
	vString *v;
	vString *n;
	unsigned int c;
	const char *sep;

	while (scope)
	{
		if (!scope->placeholder)
		{
			if (kindIndex != KIND_GHOST_INDEX)
			{
				sep = scopeSeparatorFor (lang, kindIndex, scope->kindIndex);
				v = vStringNewInit (sep);
				stringListAdd (queue, v);
			}
			/* TODO: scope field of SCOPE can be used for optimization. */
			v = vStringNewInit (scope->name);
			stringListAdd (queue, v);
			kindIndex = scope->kindIndex;
			lang = scope->langType;
			root_scope = scope;
		}
		int scopeIndex = scope->extensionFields.scopeIndex;
		scope =  getEntryInCorkQueue (scopeIndex);

		if (scope && scope->extensionFields.scopeIndex == scopeIndex)
		{
			error (WARNING,
				   "interanl error: scope information made a loop structure: %s in %s:%lu",
				   scope->name, scope->inputFileName, scope->lineNumber);
			/* Force break this while-loop. */
			scope = NULL;
		}
	}

	n = vStringNew ();
	sep = root_scope? scopeSeparatorFor (root_scope->langType, root_scope->kindIndex, KIND_GHOST_INDEX): NULL;
	if (sep)
		vStringCatS(n, sep);

	while ((c = stringListCount (queue)) > 0)
	{
		v = stringListLast (queue);
		vStringCat (n, v);
		vStringDelete (v);
		stringListRemoveLast (queue);
	}
	stringListDelete (queue);

	return vStringDeleteUnwrap (n);
}

extern void getTagScopeInformation (tagEntryInfo *const tag,
				    const char **kind, const char **name)
{
	if (kind)
		*kind = NULL;
	if (name)
		*name = NULL;

	const tagEntryInfo * scope = getEntryInCorkQueue (tag->extensionFields.scopeIndex);
	if (tag->extensionFields.scopeKindIndex == KIND_GHOST_INDEX
	    && tag->extensionFields.scopeName == NULL
	    && scope
	    && ptrArrayCount (TagFile.corkQueue) > 0)
	{
		char *full_qualified_scope_name = getFullQualifiedScopeNameFromCorkQueue(scope);
		Assert (full_qualified_scope_name);

		/* Make the information reusable to generate full qualified entry, and xformat output*/
		tag->extensionFields.scopeLangType = scope->langType;
		tag->extensionFields.scopeKindIndex = scope->kindIndex;
		tag->extensionFields.scopeName = full_qualified_scope_name;
	}

	if (tag->extensionFields.scopeKindIndex != KIND_GHOST_INDEX  &&
	    tag->extensionFields.scopeName != NULL)
	{
		if (kind)
		{
			langType lang = (tag->extensionFields.scopeLangType == LANG_AUTO)
				? tag->langType
				: tag->extensionFields.scopeLangType;
			kindDefinition *kdef = getLanguageKind (lang,
													tag->extensionFields.scopeKindIndex);
			*kind = kdef->name;
		}
		if (name)
			*name = tag->extensionFields.scopeName;
	}
}


static int   makePatternStringCommon (const tagEntryInfo *const tag,
				      int (* putc_func) (char , void *),
				      int (* puts_func) (const char* , void *),
				      void *output)
{
	int length = 0;

	char *line;
	int searchChar;
	const char *terminator;
	bool  omitted;
	size_t line_len;

	bool making_cache = false;
	int (* puts_o_func)(const char* , void *);
	void * o_output;

	static vString *cached_pattern;
	static MIOPos   cached_location;
	if (TagFile.patternCacheValid
	    && (! tag->truncateLineAfterTag)
	    && (memcmp (&tag->filePosition, &cached_location, sizeof(MIOPos)) == 0))
		return puts_func (vStringValue (cached_pattern), output);

	line = readLineFromBypassForTag (TagFile.vLine, tag, NULL);
	if (line == NULL)
	{
		/* This can be occurs if the size of input file is zero, and
		   an empty regex pattern (//) matches to the input. */
		line = "";
		line_len = 0;
	}
	else
		line_len = vStringLength (TagFile.vLine);

	if (tag->truncateLineAfterTag)
	{
		size_t truncted_len;

		truncted_len = truncateTagLineAfterTag (line, tag->name, false);
		if (truncted_len > 0)
			line_len = truncted_len;
	}

	searchChar = Option.backward ? '?' : '/';
	terminator = (line_len > 0 && (line [line_len - 1] == '\n')) ? "$": "";

	if (!tag->truncateLineAfterTag)
	{
		making_cache = true;
		cached_pattern = vStringNewOrClearWithAutoRelease (cached_pattern);

		puts_o_func = puts_func;
		o_output    = output;
		putc_func   = vstring_putc;
		puts_func   = vstring_puts;
		output      = cached_pattern;
	}

	length += putc_func(searchChar, output);
	if ((tag->boundaryInfo & BOUNDARY_START) == 0)
		length += putc_func('^', output);
	length += appendInputLine (putc_func, line, Option.patternLengthLimit,
							   output, &omitted);
	length += puts_func (omitted? "": terminator, output);
	length += putc_func (searchChar, output);

	if (making_cache)
	{
		puts_o_func (vStringValue (cached_pattern), o_output);
		cached_location = tag->filePosition;
		TagFile.patternCacheValid = true;
	}

	return length;
}

extern char* makePatternString (const tagEntryInfo *const tag)
{
	vString* pattern = vStringNew ();
	makePatternStringCommon (tag, vstring_putc, vstring_puts, pattern);
	return vStringDeleteUnwrap (pattern);
}

static tagField * tagFieldNew(fieldType ftype, const char *value, bool valueOwner)
{
	tagField *f = xMalloc (1, tagField);

	f->ftype = ftype;
	f->value = value;
	f->valueOwner = valueOwner;
	return f;
}

static void tagFieldDelete (tagField * f)
{
	if (f->valueOwner)
		eFree((void *)f->value);
	eFree (f);
}

static void attachParserFieldGeneric (tagEntryInfo *const tag, fieldType ftype, const char * value,
									  bool valueOwner)
{
	if (tag->usedParserFields < PRE_ALLOCATED_PARSER_FIELDS)
	{
		tag->parserFields [tag->usedParserFields].ftype = ftype;
		tag->parserFields [tag->usedParserFields].value = value;
		tag->parserFields [tag->usedParserFields].valueOwner = valueOwner;
		tag->usedParserFields++;
	}
	else if (tag->parserFieldsDynamic == NULL)
	{
		tag->parserFieldsDynamic = ptrArrayNew((ptrArrayDeleteFunc)tagFieldDelete);
		PARSER_TRASH_BOX(tag->parserFieldsDynamic, ptrArrayDelete);
		attachParserFieldGeneric (tag, ftype, value, valueOwner);
	}
	else
	{
		tagField *f = tagFieldNew (ftype, value, valueOwner);
		ptrArrayAdd(tag->parserFieldsDynamic, f);
		tag->usedParserFields++;
	}
}

extern void attachParserField (tagEntryInfo *const tag, bool inCorkQueue, fieldType ftype, const char * value)
{
	Assert (tag != NULL);

	if (inCorkQueue)
	{
		const char * v;
		v = eStrdup (value);

		bool dynfields_allocated = tag->parserFieldsDynamic? true: false;
		attachParserFieldGeneric (tag, ftype, v, true);
		if (!dynfields_allocated && tag->parserFieldsDynamic)
			PARSER_TRASH_BOX_TAKE_BACK(tag->parserFieldsDynamic);
	}
	else
		attachParserFieldGeneric (tag, ftype, value, false);
}

extern void attachParserFieldToCorkEntry (int index,
					 fieldType ftype,
					 const char *value)
{
	tagEntryInfo * tag = getEntryInCorkQueue (index);
	if (tag)
		attachParserField (tag, true, ftype, value);
}

extern const tagField* getParserFieldForIndex (const tagEntryInfo * tag, int index)
{
	if (index < 0
		|| tag->usedParserFields <= ((unsigned int)index) )
		return NULL;
	else if (index < PRE_ALLOCATED_PARSER_FIELDS)
		return tag->parserFields + index;
	else
	{
		unsigned int n = index - PRE_ALLOCATED_PARSER_FIELDS;
		return ptrArrayItem(tag->parserFieldsDynamic, n);
	}
}

extern const char* getParserFieldValueForType (tagEntryInfo *const tag, fieldType ftype)
{
	for (int i = 0; i < tag->usedParserFields; i++)
	{
		const tagField *f = getParserFieldForIndex (tag, i);
		if (f && f->ftype == ftype)
			return f->value;
	}
	return NULL;
}

static void copyParserFields (const tagEntryInfo *const tag, tagEntryInfo* slot)
{
	unsigned int i;
	const char* value;

	for (i = 0; i < tag->usedParserFields; i++)
	{
		const tagField *f = getParserFieldForIndex (tag, i);
		Assert(f);

		value = f->value;
		if (value)
			value = eStrdup (value);

		attachParserFieldGeneric (slot,
								  f->ftype,
								  value,
								  true);
	}

}

static tagEntryInfo *newNilTagEntry (unsigned int corkFlags)
{
	tagEntryInfoX *x = xCalloc (1, tagEntryInfoX);
	x->corkIndex = CORK_NIL;
	x->symtab = RB_ROOT;
	x->slot.kindIndex = KIND_FILE_INDEX;
	return &(x->slot);
}

static tagEntryInfoX *copyTagEntry (const tagEntryInfo *const tag,
								   unsigned int corkFlags)
{
	tagEntryInfoX *x = xMalloc (1, tagEntryInfoX);
	x->symtab = RB_ROOT;
	x->corkIndex = CORK_NIL;
	tagEntryInfo  *slot = (tagEntryInfo *)x;

	*slot = *tag;

	if (slot->pattern)
		slot->pattern = eStrdup (slot->pattern);

	slot->inputFileName = eStrdup (slot->inputFileName);
	slot->name = eStrdup (slot->name);
	if (slot->extensionFields.access)
		slot->extensionFields.access = eStrdup (slot->extensionFields.access);
	if (slot->extensionFields.implementation)
		slot->extensionFields.implementation = eStrdup (slot->extensionFields.implementation);
	if (slot->extensionFields.inheritance)
		slot->extensionFields.inheritance = eStrdup (slot->extensionFields.inheritance);
	if (slot->extensionFields.scopeName)
		slot->extensionFields.scopeName = eStrdup (slot->extensionFields.scopeName);
	if (slot->extensionFields.signature)
		slot->extensionFields.signature = eStrdup (slot->extensionFields.signature);
	if (slot->extensionFields.typeRef[0])
		slot->extensionFields.typeRef[0] = eStrdup (slot->extensionFields.typeRef[0]);
	if (slot->extensionFields.typeRef[1])
		slot->extensionFields.typeRef[1] = eStrdup (slot->extensionFields.typeRef[1]);
#ifdef HAVE_LIBXML
	if (slot->extensionFields.xpath)
		slot->extensionFields.xpath = eStrdup (slot->extensionFields.xpath);
#endif

	if (slot->extraDynamic)
	{
		int n = countXtags () - XTAG_COUNT;
		slot->extraDynamic = xCalloc ((n / 8) + 1, uint8_t);
		memcpy (slot->extraDynamic, tag->extraDynamic, (n / 8) + 1);
	}

	if (slot->sourceFileName)
		slot->sourceFileName = eStrdup (slot->sourceFileName);


	slot->usedParserFields = 0;
	slot->parserFieldsDynamic = NULL;
	copyParserFields (tag, slot);
	if (slot->parserFieldsDynamic)
		PARSER_TRASH_BOX_TAKE_BACK(slot->parserFieldsDynamic);

	return x;
}

static void clearParserFields (tagEntryInfo *const tag)
{
	unsigned int i, n;
	const char* value;

	if ( tag->usedParserFields < PRE_ALLOCATED_PARSER_FIELDS )
		n = tag->usedParserFields;
	else
		n = PRE_ALLOCATED_PARSER_FIELDS;

	for (i = 0; i < n; i++)
	{
		value = tag->parserFields[i].value;
		if (value && tag->parserFields[i].valueOwner)
			eFree ((char *)value);
		tag->parserFields[i].value = NULL;
		tag->parserFields[i].ftype = FIELD_UNKNOWN;
	}
	if (tag->parserFieldsDynamic)
	{
		ptrArrayDelete (tag->parserFieldsDynamic);
		tag->parserFieldsDynamic = NULL;
	}
}

static void deleteTagEnry (void *data)
{
	tagEntryInfo *slot = data;

	if (slot->kindIndex == KIND_FILE_INDEX)
		goto out;

	if (slot->pattern)
		eFree ((char *)slot->pattern);
	eFree ((char *)slot->inputFileName);
	eFree ((char *)slot->name);

	if (slot->extensionFields.access)
		eFree ((char *)slot->extensionFields.access);
	if (slot->extensionFields.implementation)
		eFree ((char *)slot->extensionFields.implementation);
	if (slot->extensionFields.inheritance)
		eFree ((char *)slot->extensionFields.inheritance);
	if (slot->extensionFields.scopeName)
		eFree ((char *)slot->extensionFields.scopeName);
	if (slot->extensionFields.signature)
		eFree ((char *)slot->extensionFields.signature);
	if (slot->extensionFields.typeRef[0])
		eFree ((char *)slot->extensionFields.typeRef[0]);
	if (slot->extensionFields.typeRef[1])
		eFree ((char *)slot->extensionFields.typeRef[1]);
#ifdef HAVE_LIBXML
	if (slot->extensionFields.xpath)
		eFree ((char *)slot->extensionFields.xpath);
#endif

	if (slot->extraDynamic)
		eFree (slot->extraDynamic);

	if (slot->sourceFileName)
		eFree ((char *)slot->sourceFileName);

	clearParserFields (slot);

 out:
	eFree (slot);
}

static void corkSymtabPut (tagEntryInfoX *scope, const char* name, tagEntryInfoX *item)
{
	struct rb_root *root = &scope->symtab;

	struct rb_node **new = &(root->rb_node), *parent = NULL;

	while (*new)
	{
		tagEntryInfoX *this = container_of(*new, tagEntryInfoX, symnode);
		int result = strcmp(item->slot.name, this->slot.name);

		parent = *new;

		if (result < 0)
			new = &((*new)->rb_left);
		else if (result > 0)
			new = &((*new)->rb_right);
		else
		{
			unsigned long lthis = this->slot.lineNumber;
			unsigned long litem = item->slot.lineNumber;

			/* Comparing lineNumber */
			if (litem < lthis)
				new = &((*new)->rb_left);
			else if (litem > lthis)
				new = &((*new)->rb_right);
			else
			{
				/* Comparing memory address */
				if (item < this)
					new = &((*new)->rb_left);
				else if (item > this)
					new = &((*new)->rb_right);
				else
				{
					AssertNotReached(); /* registering the same object twice. */
					return;
				}
			}
		}
	}

	verbose ("symtbl[:=] %s<-%s/%p (line: %lu)\n",
			*new? container_of(*new, tagEntryInfoX, symnode)->slot.name: "*root*",
			 item->slot.name, &item->slot, item->slot.lineNumber);
	/* Add new node and rebalance tree. */
	rb_link_node(&item->symnode, parent, new);
	rb_insert_color(&item->symnode, root);
}

static void corkSymtabUnlink (tagEntryInfoX *scope, tagEntryInfoX *item)
{
	struct rb_root *root = &scope->symtab;
	rb_erase (&item->symnode, root);
}

extern bool foreachEntriesInScope (int corkIndex,
								   const char *name,
								   entryForeachFunc func,
								   void *data)
{
	tagEntryInfoX *x = ptrArrayItem (TagFile.corkQueue, corkIndex);

	struct rb_root *root = &x->symtab;
	tagEntryInfoX *rep = NULL;

	/* More than one tag can have a same name.
	 * Visit them from the last.
	 *
	 * 1. find one of them as the representative,
	 * 2. find the last one of them from the representative with rb_next,
	 * 3. call FUNC iteratively from the last to the first.
	 */
	if (name)
	{
		struct rb_node *node = root->rb_node;
		while (node)
		{
			tagEntryInfoX *entry = container_of(node, tagEntryInfoX, symnode);
			int result;

			result = strcmp(name, entry->slot.name);

			if (result < 0)
				node = node->rb_left;
			else if (result > 0)
				node = node->rb_right;
			else
			{
				rep = entry;
				break;
			}
		}
		if (rep == NULL)
			return true;

		verbose("symtbl[<>] %s->%p\n", name, &rep->slot);
	}

	struct rb_node *last;

	if (name)
	{
		struct rb_node *tmp = &rep->symnode;
		last = tmp;

		while ((tmp = rb_next (tmp)))
		{
			tagEntryInfoX *entry = container_of(tmp, tagEntryInfoX, symnode);
			if (strcmp(name, entry->slot.name) == 0)
			{
				verbose ("symtbl[ >] %s->%p\n", name, &container_of(tmp, tagEntryInfoX, symnode)->slot);
				last = tmp;
			}
			else
				break;
		}
	}
	else
	{
		last = rb_last(root);
		verbose ("last for %d<%p>: %p\n", corkIndex, root, last);
	}

	if (!last)
	{
		verbose ("symtbl[>V] %s->%p\n", name? name: "(null)", NULL);
		return true;			/* Nothing here in this node. */
	}

	verbose ("symtbl[>|] %s->%p\n", name, &container_of(last, tagEntryInfoX, symnode)->slot);

	struct rb_node *cursor = last;
	bool revisited_rep = false;
	do
	{
		tagEntryInfoX *entry = container_of(cursor, tagEntryInfoX, symnode);
		if (!revisited_rep || !name || !strcmp(name, entry->slot.name))
		{
			verbose ("symtbl[< ] %s->%p\n", name, &entry->slot);
			if (!func (entry->corkIndex, &entry->slot, data))
				return false;
			if (cursor == &rep->symnode)
				revisited_rep = true;
		}
		else if (name)
			break;
	}
	while ((cursor = rb_prev(cursor)));

	return true;
}

struct anyEntryInScopeData {
	int index;
	bool onlyDefinitionTag;
};

static bool findName (int corkIndex, tagEntryInfo *entry, void *cbData)
{
	struct anyEntryInScopeData *data = cbData;

	if (data->onlyDefinitionTag && !isRoleAssigned (entry, ROLE_DEFINITION_INDEX))
		return true;

	data->index = corkIndex;
	return false;
}

int anyEntryInScope (int corkIndex, const char *name, bool onlyDefinitionTag)
{
	struct anyEntryInScopeData data = {
		.index = CORK_NIL,
		.onlyDefinitionTag = onlyDefinitionTag,
	};

	if (foreachEntriesInScope (corkIndex, name, findName, &data) == false)
		return data.index;

	return CORK_NIL;
}

struct anyKindsEntryInScopeData {
	int  index;
	const int *kinds;
	int  count;
	bool onlyDefinitionTag;
};

static bool findNameOfKinds (int corkIndex, tagEntryInfo *entry, void *data)
{
	struct anyKindsEntryInScopeData * kdata = data;

	for (int i = 0; i < kdata->count; i++)
	{
		int k = kdata->kinds [i];
		if (entry->kindIndex == k
			&& ((!kdata->onlyDefinitionTag)
				|| isRoleAssigned (entry, ROLE_DEFINITION_INDEX)))
		{
			kdata->index = corkIndex;
			return false;
		}
	}
	return true;
}

int anyKindEntryInScope (int corkIndex,
						 const char *name, int kind,
						 bool onlyDefinitionTag)
{
	return anyKindsEntryInScope (corkIndex, name, &kind, 1, onlyDefinitionTag);
}

int anyKindsEntryInScope (int corkIndex,
						  const char *name,
						  const int *kinds, int count,
						  bool onlyDefinitionTag)
{
	struct anyKindsEntryInScopeData data = {
		.index = CORK_NIL,
		.kinds = kinds,
		.count = count,
		.onlyDefinitionTag = onlyDefinitionTag,
	};

	if (foreachEntriesInScope (corkIndex, name, findNameOfKinds, &data) == false)
		return data.index;

	return CORK_NIL;
}

int anyKindsEntryInScopeRecursive (int corkIndex,
								   const char *name,
								   const int *kinds, int count,
								   bool onlyDefinitionTag)
{
	struct anyKindsEntryInScopeData data = {
		.index = CORK_NIL,
		.kinds = kinds,
		.count = count,
		.onlyDefinitionTag = onlyDefinitionTag,
	};

	tagEntryInfo *e;
	do
	{
		if (foreachEntriesInScope (corkIndex, name, findNameOfKinds, &data) == false)
			return data.index;

		if (corkIndex == CORK_NIL)
			break;

		e = getEntryInCorkQueue (corkIndex);
		if (!e)
			break;
		corkIndex = e->extensionFields.scopeIndex;
	}
	while (1);

	return CORK_NIL;
}

extern void registerEntry (int corkIndex)
{
	Assert (TagFile.corkFlags & CORK_SYMTAB);
	Assert (corkIndex != CORK_NIL);

	tagEntryInfoX *e = ptrArrayItem (TagFile.corkQueue, corkIndex);
	{
		tagEntryInfoX *scope = ptrArrayItem (TagFile.corkQueue, e->slot.extensionFields.scopeIndex);
		corkSymtabPut (scope, e->slot.name, e);
	}
}

extern void unregisterEntry(int corkIndex)
{
	Assert (TagFile.corkFlags & CORK_SYMTAB);
	Assert (corkIndex != CORK_NIL);

	tagEntryInfoX *e = ptrArrayItem (TagFile.corkQueue, corkIndex);
	{
		tagEntryInfoX *scope = ptrArrayItem (TagFile.corkQueue, e->slot.extensionFields.scopeIndex);
		corkSymtabUnlink (scope, e);
	}

}

static int queueTagEntry(const tagEntryInfo *const tag)
{
	static bool warned;

	int corkIndex;
	tagEntryInfoX * entry = copyTagEntry (tag,
										TagFile.corkFlags);

	if (ptrArrayCount (TagFile.corkQueue) == (size_t)INT_MAX)
	{
		if (!warned)
		{
			warned = true;
			error (WARNING,
				   "The tag entry queue overflows; drop the tag entry at %lu in %s",
				   tag->lineNumber,
				   tag->inputFileName);
		}
		return CORK_NIL;
	}
	warned = false;

	corkIndex = (int)ptrArrayAdd (TagFile.corkQueue, entry);
	entry->corkIndex = corkIndex;
	entry->slot.inCorkQueue = 1;

	return corkIndex;
}

extern void setupWriter (void *writerClientData)
{
	writerSetup (TagFile.mio, writerClientData);
}

extern bool teardownWriter (const char *filename)
{
	return writerTeardown (TagFile.mio, filename);
}

static bool isTagWritable(const tagEntryInfo *const tag)
{
	if (tag->placeholder)
		return false;

	if (! isLanguageKindEnabled(tag->langType, tag->kindIndex))
		return false;

	if (tag->extensionFields.roleBits)
	{
		size_t available_roles;

		if (!isXtagEnabled (XTAG_REFERENCE_TAGS))
			return false;

		available_roles = countLanguageRoles(tag->langType,
											 tag->kindIndex);
		if (tag->extensionFields.roleBits >=
			(makeRoleBit(available_roles)))
			return false;

		/* TODO: optimization
		   A Bitmasks representing all enabled roles can be calculated at the
		   end of initializing the parser. Calculating each time when checking
		   a tag entry is not needed. */
		for (unsigned int roleIndex = 0; roleIndex < available_roles; roleIndex++)
		{
			if (isRoleAssigned(tag, roleIndex))
			{
				if (isLanguageRoleEnabled (tag->langType, tag->kindIndex,
											 roleIndex))
					return true;
			}

		}
		return false;
	}
	else if (isLanguageKindRefOnly(tag->langType, tag->kindIndex))
	{
		error (WARNING, "PARSER BUG: a definition tag for a refonly kind(%s.%s) of is made: %s found in %s.",
			   getLanguageName(tag->langType),
			   getLanguageKind(tag->langType, tag->kindIndex)->name,
			   tag->name, tag->inputFileName);
		/* This one is not so critical. */
	}

	if (!isXtagEnabled(XTAG_ANONYMOUS)
		&& isTagExtraBitMarked(tag, XTAG_ANONYMOUS))
		return false;

	return true;
}

static void buildFqTagCache (tagEntryInfo *const tag)
{
	getTagScopeInformation (tag, NULL, NULL);
}

static void writeTagEntry (const tagEntryInfo *const tag)
{
	int length = 0;

	Assert (tag->kindIndex != KIND_GHOST_INDEX);

	DebugStatement ( debugEntry (tag); )

#ifdef WIN32
	if (getFilenameSeparator(Option.useSlashAsFilenameSeparator) == FILENAME_SEP_USE_SLASH)
	{
		Assert (((const tagEntryInfo *)tag)->inputFileName);
		char *c = (char *)(((tagEntryInfo *const)tag)->inputFileName);
		while (*c)
		{
			if (*c == PATH_SEPARATOR)
				*c = OUTPUT_PATH_SEPARATOR;
			c++;
		}
	}
#endif

	if (includeExtensionFlags ()
	    && isXtagEnabled (XTAG_QUALIFIED_TAGS)
	    && doesInputLanguageRequestAutomaticFQTag (tag)
		&& !isTagExtraBitMarked (tag, XTAG_QUALIFIED_TAGS)
		&& !tag->skipAutoFQEmission)
	{
		/* const is discarded to update the cache field of TAG. */
		buildFqTagCache ( (tagEntryInfo *const)tag);
	}

	length = writerWriteTag (TagFile.mio, tag);

	if (length > 0)
	{
		++TagFile.numTags.added;
		rememberMaxLengths (strlen (tag->name), (size_t) length);
	}
	DebugStatement ( if (TagFile.mio) mio_flush (TagFile.mio); )

	abort_if_ferror (TagFile.mio);
}

extern bool writePseudoTag (const ptagDesc *desc,
			       const char *const fileName,
			       const char *const pattern,
			       const char *const parserName)
{
	int length;

	length = writerWritePtag (TagFile.mio, desc, fileName,
							  pattern, parserName);
	if (length < 0)
		return false;

	abort_if_ferror (TagFile.mio);

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

	return true;
}

extern void corkTagFile(unsigned int corkFlags)
{
	TagFile.cork++;
	if (TagFile.cork == 1)
	{
		TagFile.corkFlags = corkFlags;
		TagFile.corkQueue = ptrArrayNew (deleteTagEnry);
		tagEntryInfo *nil = newNilTagEntry (corkFlags);
		ptrArrayAdd (TagFile.corkQueue, nil);
	}
}

extern void uncorkTagFile(void)
{
	unsigned int i;

	TagFile.cork--;

	if (TagFile.cork > 0)
		return ;

	for (i = 1; i < ptrArrayCount (TagFile.corkQueue); i++)
	{
		tagEntryInfo *tag = ptrArrayItem (TagFile.corkQueue, i);

		if (!isTagWritable(tag))
			continue;

		writeTagEntry (tag);

		if (doesInputLanguageRequestAutomaticFQTag (tag)
		    && isXtagEnabled (XTAG_QUALIFIED_TAGS)
			&& !isTagExtraBitMarked (tag, XTAG_QUALIFIED_TAGS)
			&& !tag->skipAutoFQEmission
			&& ((tag->extensionFields.scopeKindIndex != KIND_GHOST_INDEX
				 && tag->extensionFields.scopeName != NULL
				 && tag->extensionFields.scopeIndex != CORK_NIL)
				|| (tag->extensionFields.scopeKindIndex == KIND_GHOST_INDEX
					&& tag->extensionFields.scopeName == NULL
					&& tag->extensionFields.scopeIndex == CORK_NIL)))
			makeQualifiedTagEntry (tag);
	}

	ptrArrayDelete (TagFile.corkQueue);
	TagFile.corkQueue = NULL;
}

extern tagEntryInfo *getEntryInCorkQueue   (int n)
{
	if ((CORK_NIL < n) && (((size_t)n) < ptrArrayCount (TagFile.corkQueue)))
		return ptrArrayItem (TagFile.corkQueue, n);
	else
		return NULL;
}

extern tagEntryInfo *getEntryOfNestingLevel (const NestingLevel *nl)
{
	if (nl == NULL)
		return NULL;
	return getEntryInCorkQueue (nl->corkIndex);
}

extern size_t        countEntryInCorkQueue (void)
{
	return ptrArrayCount (TagFile.corkQueue);
}

extern void markTagPlaceholder (tagEntryInfo *e, bool placeholder)
{
	e->placeholder = placeholder;
}

extern int makePlaceholder (const char *const name)
{
	tagEntryInfo e;

	initTagEntry (&e, name, KIND_GHOST_INDEX);
	markTagPlaceholder(&e, true);

	/*
	 * makePlaceholder may be called even before reading any bytes
	 * from the input stream. In such case, initTagEntry fills
	 * the lineNumber field of the placeholder tag with 0.
	 * This breaks an assertion in makeTagEntry. Following adjustment
	 * is for avoiding it.
	 */
	if (e.lineNumber == 0)
		e.lineNumber = 1;

	return makeTagEntry (&e);
}

extern int makeTagEntry (const tagEntryInfo *const tag)
{
	int r = CORK_NIL;
	Assert (tag->name != NULL);
	Assert(tag->lineNumber > 0);

	if (!TagFile.cork)
		if (!isTagWritable (tag))
			goto out;

	if (tag->name [0] == '\0' && (!tag->placeholder))
	{
		if (!doesInputLanguageAllowNullTag())
			error (WARNING, "ignoring null tag in %s(line: %lu)",
			       getInputFileName (), tag->lineNumber);
		goto out;
	}

	if (TagFile.cork)
		r = queueTagEntry (tag);
	else
		writeTagEntry (tag);

	if (r != CORK_NIL)
		notifyMakeTagEntry (tag, r);

out:
	return r;
}

extern int makeQualifiedTagEntry (const tagEntryInfo *const e)
{
	int r = CORK_NIL;
	tagEntryInfo x;
	int xk;
	const char *sep;
	static vString *fqn;

	if (isXtagEnabled (XTAG_QUALIFIED_TAGS))
	{
		x = *e;
		markTagExtraBit (&x, XTAG_QUALIFIED_TAGS);

		fqn = vStringNewOrClearWithAutoRelease (fqn);

		if (e->extensionFields.scopeName)
		{
			vStringCatS (fqn, e->extensionFields.scopeName);
			xk = e->extensionFields.scopeKindIndex;
			sep = scopeSeparatorFor (e->langType, e->kindIndex, xk);
			vStringCatS (fqn, sep);
		}
		else
		{
			/* This is an top level item. prepend a root separator
			   if the kind of the item has. */
			sep = scopeSeparatorFor (e->langType, e->kindIndex, KIND_GHOST_INDEX);
			if (sep == NULL)
			{
				/* No root separator. The name of the
				   optional tag and that of full qualified tag
				   are the same; recording the full qualified tag
				   is meaningless. */
				return r;
			}
			else
				vStringCatS (fqn, sep);
		}
		vStringCatS (fqn, e->name);

		x.name = vStringValue (fqn);
		/* makeExtraTagEntry of c.c doesn't clear scope
		   related fields. */
#if 0
		x.extensionFields.scopeKind = NULL;
		x.extensionFields.scopeName = NULL;
		x.extensionFields.scopeIndex = CORK_NIL;
#endif

		bool in_subparser
			= isTagExtraBitMarked (&x,
								   XTAG_SUBPARSER);

		if (in_subparser)
			pushLanguage(x.langType);

		r = makeTagEntry (&x);

		if (in_subparser)
			popLanguage();
	}
	return r;
}

extern void setTagPositionFromTag (tagEntryInfo *const dst,
								   const tagEntryInfo *const src)
{
		dst->lineNumber = src->lineNumber;
		dst->boundaryInfo = src->boundaryInfo;
		dst->filePosition = src->filePosition;
}

static void initTagEntryFull (tagEntryInfo *const e, const char *const name,
			      unsigned long lineNumber,
			      langType langType_,
			      MIOPos      filePosition,
			      const char *inputFileName,
			      int kindIndex,
			      roleBitsType roleBits,
			      const char *sourceFileName,
			      langType sourceLangType,
			      long sourceLineNumberDifference)
{
	int i;

	Assert (getInputFileName() != NULL);

	memset (e, 0, sizeof (tagEntryInfo));
	e->lineNumberEntry = (bool) (Option.locate == EX_LINENUM);
	e->lineNumber      = lineNumber;
	e->boundaryInfo    = getNestedInputBoundaryInfo (lineNumber);
	e->langType        = langType_;
	e->filePosition    = filePosition;
	e->inputFileName   = inputFileName;
	e->name            = name;
	e->extensionFields.scopeLangType = LANG_AUTO;
	e->extensionFields.scopeKindIndex = KIND_GHOST_INDEX;
	e->extensionFields.scopeIndex     = CORK_NIL;

	Assert (kindIndex < 0 || kindIndex < (int)countLanguageKinds(langType_));
	e->kindIndex = kindIndex;

	Assert (roleBits == 0
			|| (roleBits < (makeRoleBit(countLanguageRoles(langType_, kindIndex)))));
	e->extensionFields.roleBits = roleBits;
	if (roleBits)
		markTagExtraBit (e, XTAG_REFERENCE_TAGS);

	e->extensionFields.nth = NO_NTH_FIELD;

	if (doesParserRunAsGuest ())
		markTagExtraBit (e, XTAG_GUEST);
	if (doesSubparserRun ())
		markTagExtraBit (e, XTAG_SUBPARSER);

	e->sourceLangType = sourceLangType;
	e->sourceFileName = sourceFileName;
	e->sourceLineNumberDifference = sourceLineNumberDifference;

	e->usedParserFields = 0;

	for ( i = 0; i < PRE_ALLOCATED_PARSER_FIELDS; i++ )
		e->parserFields[i].ftype = FIELD_UNKNOWN;

	if (isParserMarkedNoEmission ())
		e->placeholder = 1;
}

extern void initTagEntry (tagEntryInfo *const e, const char *const name,
						  int kindIndex)
{
	initTagEntryFull(e, name,
			 getInputLineNumber (),
			 getInputLanguage (),
			 getInputFilePosition (),
			 getInputFileTagPath (),
			 kindIndex,
			 0,
			 getSourceFileTagPath(),
			 getSourceLanguage(),
			 getSourceLineNumber() - getInputLineNumber ());
}

extern void initRefTagEntry (tagEntryInfo *const e, const char *const name,
			     int kindIndex, int roleIndex)
{
	initForeignRefTagEntry (e, name, getInputLanguage (), kindIndex, roleIndex);
}

extern void initForeignTagEntry (tagEntryInfo *const e, const char *const name,
								 langType type,
								 int kindIndex)
{
	initForeignRefTagEntry (e, name, type, kindIndex, ROLE_DEFINITION_INDEX);
}

extern void initForeignRefTagEntry (tagEntryInfo *const e, const char *const name,
									langType langType,
									int kindIndex, int roleIndex)
{
	initTagEntryFull(e, name,
			 getInputLineNumber (),
			 langType,
			 getInputFilePosition (),
			 getInputFileTagPath (),
			 kindIndex,
			 makeRoleBit(roleIndex),
			 getSourceFileTagPath(),
			 getSourceLanguage(),
			 getSourceLineNumber() - getInputLineNumber ());
}

static void    markTagExtraBitFull     (tagEntryInfo *const tag, xtagType extra, bool mark)
{
	unsigned int index;
	unsigned int offset;
	uint8_t *slot;

	Assert (extra != XTAG_UNKNOWN);

	if (extra < XTAG_COUNT)
	{
		index = (extra / 8);
		offset = (extra % 8);
		slot = tag->extra;
	}
	else if (tag->extraDynamic)
	{
		Assert (extra < countXtags ());

		index = ((extra - XTAG_COUNT) / 8);
		offset = ((extra - XTAG_COUNT) % 8);
		slot = tag->extraDynamic;
	}
	else
	{
		Assert (extra < countXtags ());

		int n = countXtags () - XTAG_COUNT;
		tag->extraDynamic = xCalloc ((n / 8) + 1, uint8_t);
		if (!tag->inCorkQueue)
			PARSER_TRASH_BOX(tag->extraDynamic, eFree);
		markTagExtraBitFull (tag, extra, mark);
		return;
	}

	if (mark)
		slot [ index ] |= (1 << offset);
	else
		slot [ index ] &= ~(1 << offset);
}

extern void    markTagExtraBit     (tagEntryInfo *const tag, xtagType extra)
{
	markTagExtraBitFull (tag, extra, true);
}

extern void    unmarkTagExtraBit    (tagEntryInfo *const tag, xtagType extra)
{
	markTagExtraBitFull (tag, extra, false);
}

extern bool isTagExtraBitMarked (const tagEntryInfo *const tag, xtagType extra)
{
	unsigned int index;
	unsigned int offset;
	const uint8_t *slot;

	Assert (extra != XTAG_UNKNOWN);

	if (extra < XTAG_COUNT)
	{
		index = (extra / 8);
		offset = (extra % 8);
		slot = tag->extra;
	}
	else if (!tag->extraDynamic)
		return false;
	else
	{
		Assert (extra < countXtags ());
		index = ((extra - XTAG_COUNT) / 8);
		offset = ((extra - XTAG_COUNT) % 8);
		slot = tag->extraDynamic;
	}
	return !! ((slot [ index ]) & (1 << offset));
}

extern bool isTagExtra (const tagEntryInfo *const tag)
{
	for (unsigned int i = 0; i < countXtags(); i++)
		if (isTagExtraBitMarked (tag, i))
			return true;
	return false;
}

static void assignRoleFull(tagEntryInfo *const e, int roleIndex, bool assign)
{
	if (roleIndex == ROLE_DEFINITION_INDEX)
	{
		if (assign)
		{
			e->extensionFields.roleBits = 0;
			markTagExtraBitFull (e, XTAG_REFERENCE_TAGS, false);
		}
	}
	else if (roleIndex > ROLE_DEFINITION_INDEX)
	{
		Assert (roleIndex < (int)countLanguageRoles(e->langType, e->kindIndex));

		if (assign)
			e->extensionFields.roleBits |= (makeRoleBit(roleIndex));
		else
			e->extensionFields.roleBits &= ~(makeRoleBit(roleIndex));
		markTagExtraBitFull (e, XTAG_REFERENCE_TAGS, e->extensionFields.roleBits);
	}
	else
		AssertNotReached();
}

extern void assignRole(tagEntryInfo *const e, int roleIndex)
{
	assignRoleFull(e, roleIndex, true);
}

extern bool isRoleAssigned(const tagEntryInfo *const e, int roleIndex)
{
	if (roleIndex == ROLE_DEFINITION_INDEX)
		return (!e->extensionFields.roleBits);
	else
		return (e->extensionFields.roleBits & makeRoleBit(roleIndex));
}

extern unsigned long numTagsAdded(void)
{
	return TagFile.numTags.added;
}

extern void setNumTagsAdded (unsigned long nadded)
{
	TagFile.numTags.added = nadded;
}

extern unsigned long numTagsTotal(void)
{
	return TagFile.numTags.added + TagFile.numTags.prev;
}

extern unsigned long maxTagsLine (void)
{
	return (unsigned long)TagFile.max.line;
}

extern void invalidatePatternCache(void)
{
	TagFile.patternCacheValid = false;
}

extern void tagFilePosition (MIOPos *p)
{
	/* mini-geany doesn't set TagFile.mio. */
	if 	(TagFile.mio == NULL)
		return;

	if (mio_getpos (TagFile.mio, p) == -1)
		error (FATAL|PERROR,
			   "failed to get file position of the tag file\n");
}

extern void setTagFilePosition (MIOPos *p, bool truncation)
{
	/* mini-geany doesn't set TagFile.mio. */
	if 	(TagFile.mio == NULL)
		return;


	long t0 = 0;
	if (truncation)
		t0 = mio_tell (TagFile.mio);

	if (mio_setpos (TagFile.mio, p) == -1)
		error (FATAL|PERROR,
			   "failed to set file position of the tag file\n");

	if (truncation)
	{
		long t1 = mio_tell (TagFile.mio);
		if (!mio_try_resize (TagFile.mio, (size_t)t1))
			error (FATAL|PERROR,
				   "failed to truncate the tag file %ld -> %ld\n", t0, t1);
	}
}

extern const char* getTagFileDirectory (void)
{
	return TagFile.directory;
}

static bool markAsPlaceholder  (int index, tagEntryInfo *e, void *data CTAGS_ATTR_UNUSED)
{
	e->placeholder = 1;
	markAllEntriesInScopeAsPlaceholder (index);
	return true;
}

extern void markAllEntriesInScopeAsPlaceholder (int index)
{
	foreachEntriesInScope (index, NULL, markAsPlaceholder, NULL);
}