--- ctags/entry.c

+++ ctags/entry.c

@@ -550,8 +550,15 @@ extern void beginEtagsFile (void)

 extern void endEtagsFile (const char *const name)

 {

 	const char *line;

+	const char *file = name;

+	size_t buildRootLen = Option.buildRoot ? strlen (Option.buildRoot) : 0;

-	fprintf (TagFile.fp, "\f\n%s,%ld\n", name, (long) TagFile.etags.byteCount);

+	if (Option.buildRoot &&

+	    strncmp (file, Option.buildRoot, buildRootLen) == 0 &&

+	    isPathSeparator (name[buildRootLen]))

+		file += buildRootLen;

+

+	fprintf (TagFile.fp, "\f\n%s,%ld\n", file, (long) TagFile.etags.byteCount);

 	if (TagFile.etags.fp != NULL)

 	{

 		rewind (TagFile.etags.fp);

@@ -834,14 +841,21 @@ extern void makeTagEntry (const tagEntryInfo *const tag)

 extern void initTagEntry (tagEntryInfo *const e, const char *const name)

 {

+	const char *file = getSourceFileTagPath ();

+	size_t buildRootLen = Option.buildRoot ? strlen (Option.buildRoot) : 0;

+

 	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 ();

+	if (Option.buildRoot &&

+	    strncmp (file, Option.buildRoot, buildRootLen) == 0 &&

+	    isPathSeparator (file[buildRootLen]))

+		file += buildRootLen;

+	e->sourceFileName  = file;

 	e->name            = name;

 }

--- ctags/options.c

+++ ctags/options.c

@@ -148,6 +148,7 @@ optionValues Option = {

 	FALSE,      /* --tag-relative */

 	FALSE,      /* --totals */

 	FALSE,      /* --line-directives */

+	NULL,       /* --buildroot */

 #ifdef DEBUG

 	0, 0        /* -D, -b */

 #endif

@@ -270,6 +271,8 @@ static optionDescription LongOptionDescription [] = {

  {0,"       Should paths be relative to location of tag file [no; yes when -e]?"},

  {1,"  --totals=[yes|no]"},

  {1,"       Print statistics about source and tag files [no]."},

+ {1,"  --buildroot=path"},

+ {1,"       Base directory to strip from file names."},

  {1,"  --verbose=[yes|no]"},

  {1,"       Enable verbose messages describing actions on each source file."},

  {1,"  --version"},

@@ -866,6 +869,15 @@ static void processFieldsOption (

 	}

 }

+static void processBuildrootOption (

+	const char *const option, const char *const parameter)

+{

+	freeString (&Option.buildRoot);

+	if (! isAbsolutePath(parameter))

+		error (FATAL, "Value for \"%s\" must be absolute path",option);

+	Option.buildRoot = stringCopy (parameter);

+}

+

 static void processFilterTerminatorOption (

 		const char *const option __unused__, const char *const parameter)

 {

@@ -1370,6 +1382,7 @@ static void processVersionOption (

  */

 static parametricOption ParametricOptions [] = {

+	{ "buildroot",              processBuildrootOption,         TRUE    },

 	{ "etags-include",          processEtagsInclude,            FALSE   },

 	{ "exclude",                processExcludeOption,           FALSE   },

 	{ "excmd",                  processExcmdOption,             FALSE   },

@@ -1818,6 +1831,7 @@ extern void freeOptionResources (void)

 	freeString (&Option.tagFileName);

 	freeString (&Option.fileList);

 	freeString (&Option.filterTerminator);

+	freeString (&Option.buildRoot);

 	freeList (&Excluded);

 	freeList (&Option.ignore);

--- ctags/options.h

+++ ctags/options.h

@@ -108,6 +108,7 @@ typedef struct sOptionValues {

 	boolean tagRelative;    /* --tag-relative file paths relative to tag file */

 	boolean printTotals;    /* --totals  print cumulative statistics */

 	boolean lineDirectives; /* --linedirectives  process #line directives */

+	char *buildRoot;        /* --buildroot  file prefix */

 #ifdef DEBUG

 	long debugLevel;        /* -D  debugging output */

 	unsigned long breakLine;/* -b  source line at which to call lineBreak() */

--- ctags/routines.c

+++ ctags/routines.c

@@ -513,7 +513,7 @@ extern int fsetpos (FILE *stream, fpos_t const *pos)

  *  Pathname manipulation (O/S dependent!!!)

  */

-static boolean isPathSeparator (const int c)

+extern boolean isPathSeparator (const int c)

 {

 	boolean result;

 #if defined (MSDOS_STYLE_PATH) || defined (VMS)

--- ctags/routines.h

+++ ctags/routines.h

@@ -120,6 +120,7 @@ extern boolean isSameFile (const char *const name1, const char *const name2);

 extern int fgetpos  (FILE *stream, fpos_t *pos);

 extern int fsetpos  (FILE *stream, fpos_t *pos);

 #endif

+extern boolean isPathSeparator (const int c);

 extern const char *baseFilename (const char *const filePath);

 extern const char *fileExtension (const char *const fileName);

 extern boolean isAbsolutePath (const char *const path);