29.1 What is an Annotation?

Annotations start with a newline character, two ‘control-z’ characters, and the name of the annotation. If there is no additional information associated with this annotation, the name of the annotation is followed immediately by a newline. If there is additional information, the name of the annotation is followed by a space, the additional information, and a newline. The additional information cannot contain newline characters.

Any output not beginning with a newline and two ‘control-z’ characters denotes literal output from ROCGDB. Currently there is no need for ROCGDB to output a newline followed by two ‘control-z’ characters, but if there was such a need, the annotations could be extended with an ‘escape’ annotation which means those three characters as output.

The annotation level, which is specified using the --annotate command line option (see Choosing Modes), controls how much information ROCGDB prints together with its prompt, values of expressions, source lines, and other types of output. Level 0 is for no annotations, level 1 is for use when ROCGDB is run as a subprocess of GNU Emacs, level 3 is the maximum annotation suitable for programs that control ROCGDB, and level 2 annotations have been made obsolete (see Limitations of the Annotation Interface in GDB’s Obsolete Annotations).

set annotate level

The ROCGDB command set annotate sets the level of annotations to the specified level.

show annotate ¶

Show the current annotation level.

This chapter describes level 3 annotations.

A simple example of starting up ROCGDB with annotations is:

$ gdb --annotate=3
GNU gdb 6.0
Copyright 2003 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it
under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty"
for details.
This GDB was configured as "i386-pc-linux-gnu"

^Z^Zpre-prompt
(gdb)
^Z^Zprompt
quit

^Z^Zpost-prompt
$

Here ‘quit’ is input to ROCGDB; the rest is output from ROCGDB. The three lines beginning ‘^Z^Z’ (where ‘^Z’ denotes a ‘control-z’ character) are annotations; the rest is output from ROCGDB.