18.1 Interfacing to etags

Automake will generate rules to generate `TAGS' files for use with GNU Emacs under some circumstances.

If any C, C++ or Fortran 77 source code or headers are present, then tags and TAGS targets will be generated for the directory.

At the topmost directory of a multi-directory package, a tags target file will be generated which, when run, will generate a `TAGS' file that includes by reference all `TAGS' files from subdirectories.

The tags target will also be generated if the variable ETAGS_ARGS is defined. This variable is intended for use in directories which contain taggable source that etags does not understand. The user can use the ETAGSFLAGS to pass additional flags to etags; AM_ETAGSFLAGS is also available for use in `Makefile.am'.

Here is how Automake generates tags for its source, and for nodes in its Texinfo file:

ETAGS_ARGS = automake.in --lang=none \ --regex='/^@node[ \t]+\([^,]+\)/\1/' automake.texi

If you add filenames to `ETAGS_ARGS', you will probably also want to set `TAGS_DEPENDENCIES'. The contents of this variable are added directly to the dependencies for the tags target.

Automake also generates a ctags target which can be used to build vi-style `tags' files. The variable CTAGS is the name of the program to invoke (by default `ctags'); CTAGSFLAGS can be used by the user to pass additional flags, and AM_CTAGSFLAGS can be used by the `Makefile.am'.

Automake will also generate an ID target which will run mkid on the source. This is only supported on a directory-by-directory basis.

Automake also supports the GNU Global Tags program. The GTAGS target runs Global Tags automatically and puts the result in the top build directory. The variable GTAGS_ARGS holds arguments which are passed to gtags.