* Makefile.in: Build the Semantic manual.

[bpt/emacs.git] / doc / misc / sem-user.texi

@c This file is included by semantic.texi

@c Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007
@c Free Software Foundation, Inc.

@c Permission is granted to copy, distribute and/or modify this
@c document under the terms of the GNU Free Documentation License,
@c Version 1.3 or any later version published by the Free Software
@c Foundation; with no Invariant Sections, no Front-Cover Texts, and
@c no Back-Cover Texts.  A copy of the license is included in the
@c section entitled ``GNU Free Documentation License''.

You can begin using @semantic{} by enabling Semantic mode, a global
minor mode: type @kbd{M-x semantic-mode}, or click on the @samp{Source
Code Parsers (Semantic)} menu item in the @samp{Tools} menu.

When Semantic mode is turned on, Emacs automatically parses each file
you visit.  This allows you to use @semantic{} user commands in those
buffers.  It also enables a number of ``helper'' minor modes for
saving tags, displaying tag information, and so forth.  @xref{Semantic
mode}.

To enable Semantic mode each time you start Emacs, add the line
@code{(semantic-mode 1)} to your initialization file.  @xref{Init
File,,,emacs,Emacs manual}.

@menu
* Semantic mode::   Global minor mode for @semantic{}.
* SemanticDB::      Caching parsed buffers between sessions.
* Idle Scheduler::  Performing @semantic{} operations when idle.
@end menu

@node Semantic mode
@section Semantic mode
@cindex Semantic mode

Semantic mode is a global minor mode for @semantic{} as a whole.  When
enabled, each file you visit is automatically parsed, provided its
major mode is specified in the variable
@code{semantic-new-buffer-setup-functions} (the default is to parse
every buffer @semantic{} knows how to parse).

In each parser-enabled buffer, a number of @semantic{} commands are
available for navigating, querying, and editing source code.
@xref{Semantic mode user commands}.  Enabling Semantic mode also
installs a @samp{Development} menu on the menu-bar, with many of these
commands.

In addition, enabling Semantic mode turns on certain auxilliary global
minor modes, as specified by the variable
@code{semantic-default-submodes}.  The default auxilliary modes are
SemanticDB mode (@pxref{SemanticDB}) and Global Semantic Idle
Scheduler mode.  You can also toggle the auxilliary minor modes
separately, using their mode functions (e.g. @kbd{M-x
semanticdb-minor-mode}), or via the @samp{Development} menu.  These
auxilliary minor modes are described in the following sections.

@defvar semantic-new-buffer-setup-functions
The value of this variable is an alist of functions to call for
setting up @semantic{} parsing in the buffer.  Each element has the
form @code{(@var{mode} . @var{fn})}, where @var{mode} is a value of
@code{major-mode} for the buffer and @var{fn} is the corresponding
function for setting up the parser.  @var{fn} is called, with no
arguments, after the major mode is initialized (and after the mode
hooks have been run).

The default value enables @semantic{} for all supported major modes
(i.e., C, C++, Scheme, Javascript, Java, HTML, SRecode, and Make), but
you can remove modes from this list if you don't want to use
@semantic{} with them.
@end defvar

@defvar semantic-default-submodes
The value of this variable is a list of symbols, specifying the
auxilliary minor modes to enable when enabling Semantic mode.  The
valid mode symbols are:

@itemize
@item @code{semantic-idle-scheduler-mode} (@pxref{Idle Scheduler}).
@item @code{semanticdb-minor-mode} (@pxref{SemanticDB}).
@item @code{semantic-idle-summary-mode} (@pxref{Idle Summary Mode}).
@item @code{semantic-idle-completions-mode} (@pxref{Idle Completions Mode}).
@item @code{semantic-highlight-func-mode}
@item @code{semantic-decoration-mode}
@item @code{semantic-stickyfunc-mode}
@item @code{semantic-mru-bookmark-mode}
@end itemize
@end defvar

@menu
* Semantic mode user commands::
@end menu

@node Semantic mode user commands
@subsection Semantic mode user commands

Semantic mode provides a number of commands for navigating, querying,
and editing source code in a language-aware manner.  These commands
generally act on @dfn{tags}, which are the source-code units deemed
``important'' by the present programming language (e.g. functions in
the C programming language).

These commands may be used in any buffer that has been parsed by
@semantic{}.  Several of them prompt for a tag name using the
minibuffer; here, the @kbd{TAB} key can be used to complete tag names.
Others act on the @dfn{current tag}, meaning the tag at (or around)
point.

@table @kbd
@item \C-c , j
Prompt for a tag defined in the current file, and move point to it
(@code{semantic-complete-jump-local}).

@item \C-c , J
Prompt for a tag defined in any file that Emacs has parsed, and move
point to it (@code{semantic-complete-jump}).

@item \C-c , l
Display a list of the possible completions of the current tag
(@code{semantic-analyze-possible-completions}).

@item \C-c , g
Prompt for a tag, and display a list of tags that call it
(@code{semantic-symref-symbol}).

@item \C-c , G
Display a list of tags that call the current tag
(@code{semantic-symref}).

@item \C-c , p
Move point to the previous tag (@code{senator-previous-tag}).

@item \C-c , n
Move point to the next tag (@code{senator-next-tag}).

@item \C-c , u
Move point ``up'' one reference (@code{senator-go-to-up-reference}).
The meaning of ``up'' is language-dependent; in C++, for instance,
this means moving to the parent of the current tag.

@item \C-c, @key{SPC}
(@code{semantic-complete-analyze-inline})

@item \C-c,\C-w
Kill the current tag (@code{senator-kill-tag}).  This removes the text
for that tag, placing it in the kill ring.  You can retrieve the text
with @kbd{C-y}.  This also places the tag in the @dfn{tag ring}, so
that you can yank it with @kbd{\C-c,\C-y}, below.

@item \C-c,\M-w
Copy the current tag into the kill ring as well as the tag ring
(@code{senator-copy-tag}).

@item \C-c,\C-y
Yank a tag from the tag ring (@code{senator-yank-tag}).

@item \C-c,r
Copy the current tag into a register
(@code{senator-copy-tag-to-register}).  With an optional argument,
kill it as well.  This allows you to insert or jump to that tag with
the usual register commands.  @xref{Registers,,,emacs,Emacs manual}.

@item ?\C-c , @kbd{up}
Transpose the current tag with the previous one
(@code{senator-transpose-tags-up}).

@item ?\C-c ?, @kbd{down}
Transpose the current tag with the next one
(@code{senator-transpose-tags-down}).
@end table

@node SemanticDB
@section Semantic Database
@cindex SemanticDB

The Semantic Database (SemanticDB) caches the results of parsing
source code files.  This data can be saved to disk when you exit
Emacs, and reloaded automatically when you subsequently revisit the
same source code files.  This saves time by eliminating the need to
re-parse unmodified files.

SemanticDB also provides an @acronym{API} that programs can use to
acquire information about source code tags.  This information can be
accessed without loading the original the source files into memory.
It can also be used to create alternate ``back-ends'' for storing tag
information in alternative on-disk formats.

By default, SemanticDB is enabled together with Semantic mode.  To
disable it, remove it from @code{semantic-default-submodes}
(@pxref{Semantic mode}).  You can also enable or disable SemanticDB
with @kbd{M-x global-semanticdb-minor-mode}.

@deffn Command global-semanticdb-minor-mode
Toggle SemanticDB mode.  When enabled, any source code parsed by
@semantic{} is cached in a database.
@end deffn

SemanticDB offers a large number of customizable options, which are
described in the following subsections.

@menu
* Semanticdb Tag Storage::
* Semanticdb Search Configuration::
* Changing Backends::
* Script Generated Cache Files::
* Create System Databases::
@end menu

@node Semanticdb Tag Storage
@subsection Semanticdb Tag Storage

Each time you exit Emacs, any data cached by SemanticDB is saved in
the directory @file{.emacs.d/semanticdb/}, located in your home
directory.  Within this directory, the cache data is written into a
set of files according to a SemanticDB-specific filename convention.
If the SemanticDB directory does not exist, Emacs first asks if you
want to create it.

You can change the name of the SemanticDB directory by customizing the
variable @code{semanticdb-default-save-directory}.

@anchor{semanticdb-default-save-directory}
@deffn Option semanticdb-default-save-directory
The name of the directory where SemanticDB cache files are saved.  If
the value is @code{nil}, SemanticDB saves its data into a single file,
in the current directory, whose filename is given by
@code{semanticdb-default-file-name}.
@end deffn

@anchor{semanticdb-default-file-name}
@deffn Option semanticdb-default-file-name
The name of a cache file in which to save SemanticDB, when
@code{semanticdb-default-save-directory} is @code{nil}.
@end deffn

You can force SemanticDB to save the data from only certain files, or
suppress saving altogether, by customizing
@code{semanticdb-persistent-path}:

@anchor{semanticdb-persistent-path}
@deffn Option semanticdb-persistent-path
List of valid paths for SemanticDB to cache.  Each element should be a
directory name (a string); then the parse data from any file in that
directory is saved.

As a special exception, the value of this variable can be a list
containing a single symbol: @code{never}, @code{always}, or
@code{project}.  The symbol @code{never} disables saving anywhere;
@code{always} enables saving everywhere; and @code{project} enables
saving directory based on the variable
@code{semanticdb-project-predicate-functions}.

The default value is @code{(always)}.
@end deffn

@anchor{semanticdb-project-predicate-functions}
@defvar semanticdb-project-predicate-functions
The value of this variable is a list of predicates for indicating that
a directory belongs to a project.  This list is used when the value of
@code{semanticdb-persistent-path} is @code{(project)}.  If the list is
empty, all paths are considered valid.

Project management packages, such as EDE (@pxref{Top,,,ede,EDE
manual}), may add their own predicates with @dfn{add-hook} to this
variable.  This allows SemanticDB to save tag caches in directories
controlled by them.
@end defvar

@anchor{semanticdb-save-database-hooks}
@deffn Option semanticdb-save-database-hooks
Abnormal hook run after a database is saved.  Each function is called
with one argument, the object representing the database recently
written.
@end deffn

@node Semanticdb Search Configuration
@subsection Semanticdb Search Configuration

  When another part of @semantic{} (or another Emacs package using
@semantic{}) searches for a tag within SemanticDB, the SemanticDB
library may perform a search in the locations of the database:

@enumerate
@item
The entries defined by the current file.
@item
The entries defined by the @dfn{include files} of the current file.
@item
The entries defined by the include files included from the include
files (and so on, recursively).
@end enumerate

In C and C++, for instance, include files are defined with the
@samp{#include} preprocessor directive (SemanticDB tries to
distinguish between project and system headers, based on the @code{""}
and @code{<>} filename delimiters).  Include directives are matched to
filenames in the SemanticDB cache using the following criteria:

@enumerate
@item
Whether the file is in the same directory as the current file
@item
Whether the file is in the same project, as defined by EDE
(@pxref{Top,,,ede,EDE manual}) or the @code{semanticdb-project-roots}
variable (@pxref{Semanticdb Roots}).
@item
Whether the file is in the @dfn{system include path} (@pxref{Include
paths}).
@end enumerate

@menu
* Semanticdb Roots::    Specifying the root of different projects
* Include paths::       Add/Remove directories to include search paths
* Search Throttle::     Controlling how semanticdb searches occur
* Semanticdb search debugging commands::
@end menu

@node Semanticdb Roots
@subsubsection SemanticDB project roots

Project roots are the ``top-level'' directories for a single code
project.  With the exception of system directories, SemanticDB
searches are usually limited to the current single code project.
Therefore, it is helpful to specify the project root if you want
@semantic{} tag searches to work correctly.

@anchor{semanticdb-project-roots}
@deffn Option semanticdb-project-roots
The value of this variable is a list of directories (strings) that are
project root.  All subdirectories of a project root are considered
part of the same project.  This variable can be overriden by project
management programs via @code{semanticdb-project-root-functions}.
@end deffn

@anchor{semanticdb-project-root-functions}
@defvar semanticdb-project-root-functions
The value of this variable is a list of functions to determine a given
directory's project root.  These functions are called, one at a time,
with one argument (the directory name), and must return either
@code{nil}, a string (the project root), or a list of strings
(multiple project roots, for complex systems).  The first
non-@code{nil} return value, if any, is taken to be the project root,
overriding @code{semanticdb-project-roots}.
@end defvar

If you use EDE for project management, it will set
@code{semanticdb-project-root-functions} automatically.
@xref{Top,,,ede,EDE manual}.

@node Include paths
@subsubsection Include Paths

System include paths are standard locations to find source code tags,
such as the @dfn{header files} in @file{/usr/include} and its
subdirectories on Unix-like operating systems.  You can add and remove
system include paths using the following commands:

@anchor{semantic-add-system-include}
@deffn Command semantic-add-system-include dir &optional mode
This command prompts for a directory, @var{dir}, and adds it as a
system include path for the current major mode.  When called
non-interactively, the major mode can be specified with the @var{mode}
argument.
@end deffn

@anchor{semantic-remove-system-include}
@deffn Command semantic-remove-system-include dir &optional mode
This command prompt for a directory, @var{dir}, and removes it from
the system include path for the current major mode (or @var{mode}).
@end deffn

@anchor{semantic-customize-system-include-path}
@deffn Command semantic-customize-system-include-path &optional mode
Customize the system include path for the current major mode (or
@code{mode}).
@end deffn

@anchor{semanticdb-implied-include-tags}
@defun semanticdb-implied-include-tags
Include tags implied for all files of a given mode.  You can set this
variable with @code{defvar-mode-local} for a particular mode so that
any symbols that exist for all files for that mode are included.
@end defun

@c @xref{Search Optimization}, for more information on include paths.

@node Search Throttle
@subsubsection SemanticDB Search Throttle

The SemanticDB search throttle is a variable that may be configured by
a language support author.  If you need to customize this for
yourself, you may need to override the mode values in a mode support
hook.

@defvar semanticdb-find-default-throttle
@anchor{semanticdb-find-default-throttle}
The default throttle for @code{semanticdb-find} routines.
The throttle controls how detailed the list of database
tables is for a symbol lookup.  The value is a list with
the following keys:

@table @code
@item file
The file the search is being performed from.  This option is here for
completeness only, and is assumed to always be on.
@item local
Tables from the same local directory are included.  This includes
files directly referenced by a file name which might be in a different
directory.
@item project
Tables from the same local project are included If @code{project} is
specified, then @code{local} is assumed.
@item unloaded
If a table is not in memory, load it.  If it is not cached on disk
either, get the source, parse it, and create the table.
@item system
Tables from system databases.  These are specifically tables
from system header files, or language equivalent.
@item recursive
For include based searches, includes tables referenced by included
files.
@item omniscience
Included system databases which are omniscience, or somehow know
everything.  Omniscience databases are found in
@code{semanticdb-project-system-databases}.  The Emacs Lisp system
@var{db} is an omniscience database.
@end table

@end defvar

To set the throttle, use a command like this:

@example
(setq-mode-local c-mode
		 semanticdb-find-default-throttle
		 '(project unloaded system recursive))
@end example

The default value of the throttle is for maximum accuracy at the
expense of time taken to perform a particular look-up.  The throttle
is tweaked by @code{semantic-idle-summary-mode} to remove 'unloaded,
thus removing poor speed at unexpected times.

@node Semanticdb search debugging commands
@subsubsection Semanticdb search debugging commands

You can use @kbd{M-x semanticdb-dump-all-table-summary RET} to see the
list of databases that will be searched from a given buffer.  It
should include DBs for the directories you expect.  You can follow up
with @kbd{M-x semanticdb-find-test-translate-path RET} to then make
sure specific tables from the path are discovered correctly.

Alternately, you can get a list of include files @semantic{}
encountered, but could not find on disk using
@kbd{M-x semanticdb-find-adebug-lost-includes RET}.

Once you have used the below functions to debug the problem, you may
need to reconfigure how @semantic{} finds include files.
See @ref{Semanticdb Search Configuration}.  If the search config is
ok, you may need to configure the search throttle. See @ref{Search Throttle}.

@deffn Command semanticdb-dump-all-table-summary
@anchor{semanticdb-dump-all-table-summary}
Dump a list of all databases in Emacs memory.
@end deffn

@deffn Command semanticdb-find-test-translate-path &optional arg
@anchor{semanticdb-find-test-translate-path}
Call and output results of @dfn{semanticdb-find-translate-path}
With @var{arg} non-@code{nil}, specify a @var{brutish} translation.
@end deffn

@deffn Command semanticdb-find-adebug-lost-includes
@anchor{semanticdb-find-adebug-lost-includes}
Translate the current path, then display the lost includes.
Examines the variable @code{semanticdb-find-lost-includes}.
@end deffn

Lastly, you can test an explicit search term using this command:

@deffn Command semantic-adebug-searchdb regex
@anchor{semantic-adebug-searchdb}
Search the semanticdb for @var{regex} for the current buffer.
Display the results as a debug list.
@end deffn

@node Changing Backends
@subsection Changing Backends

If you want to use some other form of backend, you can use this
variable to choose which back end class to use for your general tag
storage.

The default is to save databases in flat files.  Alternatively, you
could write a new database backend that stores tags into a database,
or other storage system.

@defvar semanticdb-new-database-class
@anchor{semanticdb-new-database-class}
The default type of database created for new files.
This can be changed on a per file basis, so that some directories
are saved using one mechanism, and some directories via a different
mechanism.
@end defvar

@node Script Generated Cache Files
@subsection Script Generated Cache Files

You can create new semantic databases with the @file{semanticdb.sh}
script file.  Give this script the directory you want parsed, and it
will create a cache file for you.

@example
$ semanticdb.sh *.el
@end example

To use these generated tables, you would likely need to restart Emacs.

@node Create System Databases
@subsection Create System Databases

If your supported language stores the system libraries in readily
available parsable source code, you can pre-generate database files
for them once, which will be used over and over for tools such as
summary-mode, or the analyzer.

@deffn Command semanticdb-create-ebrowse-database dir
@anchor{semanticdb-create-ebrowse-database}
Create an @var{ebrowse} database for directory @var{dir}.
The database file is stored in ~/.semanticdb, or whichever directory
is specified by @code{semanticdb-default-system-save-directory}.
@end deffn


@node Idle Scheduler
@section Idle Scheduler
@cindex Idle Scheduler

The Idle Scheduler in @semantic{} performs multiple duties.

The primary job is to schedule buffer parsing in idle time.  The
first buffer whose cache is checked is the current buffer.  After
this, all other buffers are checked.

Once that has been accomplished, scheduled idle processes that use the
semantic tag tables are run.

@deffn Command global-semantic-idle-scheduler-mode &optional arg
@anchor{global-semantic-idle-scheduler-mode}
Toggle global use of option @dfn{semantic-idle-scheduler-mode}.
The idle scheduler with automatically reparse buffers in idle time,
and then schedule other jobs setup with @dfn{semantic-idle-scheduler-add}.
If @var{ARG} is positive, enable, if it is negative, disable.
If @var{ARG} is @code{nil}, then toggle.
@obsolete{global-semantic-auto-parse-mode,global-semantic-idle-scheduler-mode}
@end deffn

@obsolete{semantic-auto-parse-mode, semantic-idle-scheduler-mode}

@deffn Option semantic-idle-scheduler-idle-time
@anchor{semantic-idle-scheduler-idle-time}
Time in seconds of idle before scheduling events.
This time should be short enough to ensure that idle-scheduler will be
run as soon as Emacs is idle.
@end deffn

@deffn Option semantic-idle-scheduler-mode-hook
@anchor{semantic-idle-scheduler-mode-hook}
Hook run at the end of function @dfn{semantic-idle-scheduler-mode}.
@end deffn

@deffn Option semantic-idle-scheduler-verbose-flag
@anchor{semantic-idle-scheduler-verbose-flag}
Non-@code{nil} means that the idle scheduler should provide debug messages.
Use this setting to debug idle activities.
@end deffn

You can add new functionality to the idle scheduler by reading the
Application Developers Guide
@inforef{Idle Scheduling, , semantic-appdev.info}.

@menu
* Reparsing Options::           Reparsing the current buffer in idle time
* Idle Working Options::        Options for extra work done at idle time
* Debugging Idle Time Issues::  How to produce good bug reports.
* Idle Summary Mode::           Display prototype of symbol under cursor
* Idle Completions Mode::       Smart completion pop-up help.
@end menu

@node Reparsing Options
@subsection Reparsing Options

The Idle Scheduler will automatically reparse all buffers that need
it.  User input at any time will cancel the operations and return to
normal editing.

@deffn Option semantic-idle-scheduler-max-buffer-size
@anchor{semantic-idle-scheduler-max-buffer-size}
Maximum size in bytes of buffers automatically reparsed.
If this value is less than or equal to @var{0}, buffers are automatically
reparsed regardless of their size.
@end deffn

@deffn Option semantic-idle-scheduler-no-working-message
@anchor{semantic-idle-scheduler-no-working-message}
If non-@code{nil}, disable display of working messages during parse.
@end deffn

@deffn Option semantic-idle-scheduler-working-in-modeline-flag
@anchor{semantic-idle-scheduler-working-in-modeline-flag}
Non-@code{nil} means show working messages in the mode line.
Typically, parsing will show messages in the minibuffer.
This will move the parse message into the modeline.
@end deffn

@defvar semantic-before-idle-scheduler-reparse-hooks
@anchor{semantic-before-idle-scheduler-reparse-hooks}
Hooks run before option @code{semantic-idle-scheduler} begins parsing.
If any hook throws an error, this variable is reset to nil.
This hook is not protected from lexical errors.
@end defvar

@defvar semantic-after-idle-scheduler-reparse-hooks
@anchor{semantic-after-idle-scheduler-reparse-hooks}
Hooks run after option @code{semantic-idle-scheduler} has parsed.
If any hook throws an error, this variable is reset to nil.
This hook is not protected from lexical errors.
@end defvar

@node Idle Working Options
@subsection Idle Working Options

Similiar to the reparsing that occurs at short intervals in idle
time, there is extra work that can be controlled to occur in idle time
also.

Idle work occurs after a longer delay, and can be very time
consuming.  The work done includes:

@table @asis
@item Create Include Path Caches
Create the optimized search caches needed for symbol lookup.
@item Create Type Cache
Create the datatype caches needed for intellisense features.
@item Save Databases
All file-based @semantic{} databases are saved to disk.
@item Parse neighboring files
All files in the same directory as the current buffer are
speculatively parsed.
@end table

These features can be controlled with the following variables:

@deffn Option semantic-idle-scheduler-work-idle-time
@anchor{semantic-idle-scheduler-work-idle-time}
Time in seconds of idle before scheduling big work.
This time should be long enough that once any big work is started, it is
unlikely the user would be ready to type again right away.
@end deffn

@deffn Option semantic-idle-work-parse-neighboring-files-flag
@anchor{semantic-idle-work-parse-neighboring-files-flag}
Non-@code{nil} means to parse files in the same dir as the current buffer.
Disable to prevent lots of excessive parsing in idle time.
@end deffn

@node Debugging Idle Time Issues
@subsection Debugging Idle Time Issues

If you see errors produced in idle time, it could be an indication of a
more serious issue elsewhere.  It is not enough to enable
@code{debug-on-error}, as the idle timer tries to keep errors under
wraps.

Instead, there are two commands you can use whenever you see an idle
error.

@deffn Command semantic-debug-idle-function
@anchor{semantic-debug-idle-function}
Run the Semantic idle function with debugging turned on.
@end deffn

@deffn Command semantic-debug-idle-work-function
@anchor{semantic-debug-idle-work-function}
Run the Semantic idle work function with debugging turned on.
@end deffn

Once you identify the general location of the idle error, you can send
the stack trace to the mailing list, or perhaps find a more focused
way to reproduce the issue.

@node Idle Summary Mode
@subsection Idle Summary Mode

Similar to the Emacs Lisp facility eldoc,
@code{semantic-idle-summary-mode} will display the prototype, or other
helpful doc about the symbol currently under point.


@deffn semantic-idle-summary-mode &optional arg
@anchor{semantic-idle-summary-mode}
Display a tag summary of the lexical token under the cursor.
This means for getting the current tag to display information can
be overriden with @code{idle-summary-current-symbol-info}.
This is a minor mode which performs actions during idle time.
With prefix argument ARG, turn on if positive, otherwise off.  The
minor mode can be turned on only if semantic feature is available and
the current buffer was set up for parsing.  Return non-nil if the
minor mode is enabled
@end deffn

@obsolete{semantic-summary-mode, semantic-idle-summary-mode}

@deffn Option semantic-idle-summary-function
@anchor{semantic-idle-summary-function}
Function to use when displaying tag information during idle time.
Some useful functions are found in @code{semantic-format-tag-functions}.
@end deffn

@defvar semantic-idle-summary-out-of-context-faces
@anchor{semantic-idle-summary-out-of-context-faces}
List of font-lock faces that indicate a useless summary context.
Those are generally faces used to highlight comments or strings.

It might be useful to override this variable to add comment faces
specific to a major mode.  For example, in jde mode:

@example
(defvar-mode-local jde-mode semantic-idle-summary-out-of-context-faces
   (append (default-value 'semantic-idle-summary-out-of-context-faces)
	   '(jde-java-font-lock-doc-tag-face
	     jde-java-font-lock-link-face
	     jde-java-font-lock-bold-face
	     jde-java-font-lock-underline-face
	     jde-java-font-lock-pre-face
	     jde-java-font-lock-code-face)))
@end example

@end defvar

@node Idle Completions Mode
@subsection Idle Completions Mode

The definition of smart completion is described in the Analyzer
section @ref{Analyzer}.

The Idle Completions mode will calculate the list of possible
completions in idle time, and display them in a popup list, or other
inline completion mechanism.

@deffn semantic-idle-completions-mode &optional arg
@anchor{semantic-idle-completions-mode}
Display a tooltip with a list of possible completions near the cursor.
There is no convenience for performing a completion replacement.  For
that you should bind @code{semantic-ia-complete-symbol}.
This is a minor mode which performs actions during idle time.
With prefix argument ARG, turn on if positive, otherwise off.  The
minor mode can be turned on only if semantic feature is available and
the current buffer was set up for parsing.  Return non-nil if the
minor mode is enabled
@end deffn

This mode operates by using the command
@code{semantic-complete-inline-analyzer}.

Idle completion uses the completion function
@code{semantic-complete-analyze-inline-idle}.  Changing the behavior of
the idle completion popups should be done through those utilities.

@deffn Command semantic-complete-analyze-inline-idle
@anchor{semantic-complete-analyze-inline-idle}
Perform prompt completion to do in buffer completion.
@dfn{semantic-analyze-possible-completions} is used to determine the
possible values.
The function returns immediately, leaving the buffer in a mode that
will perform the completion.
Configure @code{semantic-complete-inline-analyzer-idle-displayor-class}
to change how completion options are displayed.
@end deffn

@deffn Option semantic-complete-inline-analyzer-idle-displayor-class
@anchor{semantic-complete-inline-analyzer-idle-displayor-class}
Class for displayor to use with inline completion at idle time.

Customize this variable to get a list of options, such as popup
tooltips, ghosting text, or traditional completion tools.
@end deffn