You can begin using semantic by enabling Semantic mode, a global minor mode: type M-x semantic-mode, or open the Tools menu and click on the menu item named Source Code Parsers (Semantic).  See Semantic mode.

When Semantic mode is turned on, Emacs automatically parses each file you visit.  You can then use semantic user commands in those buffers (see Semantic mode user commands).  You can also choose to enable a number of ``helper'' minor modes for saving tags, displaying tag information, and so forth.

To enable Semantic mode each time you start Emacs, add the line (semantic-mode 1) to your initialization file.  See Init File (Emacs manual).

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 semantic-new-buffer-setup-functions (the default value of this variable sets up parsing for all the parsers included with Emacs, but you may add to it if you install additional parsers).

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

In addition, enabling Semantic mode turns on certain auxiliary global minor modes.  The variable semantic-default-submodes determines which auxiliary modes are enabled; the defaults are SemanticDB mode (see SemanticDB) and Global Semantic Idle Scheduler mode (see Idle Scheduler).  You can also toggle the auxiliary minor modes separately, using their mode functions (e.g., M-x semanticdb-minor-mode), or via the Development menu.  The various auxiliary minor modes are described in the following sections.

 -- Variable: 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 (MODE . FN), where MODE is a value of major-mode for the buffer and FN is the corresponding function for setting up the parser.  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.

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

       * global-semantic-idle-scheduler-mode (see Idle Scheduler).

       * global-semanticdb-minor-mode (see SemanticDB).

       * global-semantic-idle-summary-mode (see Idle Summary Mode).

       * global-semantic-idle-completions-mode (see Idle Completions Mode).

       * global-semantic-highlight-func-mode (see Highlight Func Mode).

       * global-semantic-decoration-mode (see Tag Decoration Mode).

       * global-semantic-stickyfunc-mode (see Sticky Func Mode).

       * global-semantic-mru-bookmark-mode (see MRU Bookmarks).

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 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 TAB key can be used to complete tag names. Others act on the current tag, meaning the tag at (or around) point.

C-c , j
     Prompt for a tag defined in the current file, and move point to it (semantic-complete-jump-local).

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

C-c , l
     Display a list of the possible completions of the current tag (semantic-analyze-possible-completions).

C-c , g
     Prompt for a tag, and display a list of tags that call it (semantic-symref-symbol).  This relies on the presence of an external symbol reference tool.  See SymRef.

C-c , G
     Display a list of tags that call the current tag (semantic-symref).  This relies on the presence of an external symbol reference tool.  See SymRef.

C-c , p
     Move point to the previous tag (senator-previous-tag).

C-c , n
     Move point to the next tag (senator-next-tag).

C-c , u
     Move point ``up'' one reference (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.

C-c, SPC
     Display a list of possible completions for the symbol at point (semantic-complete-analyze-inline).  This also activates a special set of keybindings for choosing a completion: RET accepts the current completion, M-n and M-p cycle through possible completions, TAB completes as far as possible and then cycles, and C-g or any other key aborts the completion. See Smart Completion.

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

C-c , M-w
     Copy the current tag into the kill ring as well as the tag ring (senator-copy-tag).

C-c , C-y
     Yank a tag from the tag ring (senator-yank-tag).

C-c , r
     Copy the current tag into a register (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.  See Registers (Emacs manual).

C-c , up
     Transpose the current tag with the previous one (senator-transpose-tags-up).

C-c , down
     Transpose the current tag with the next one (senator-transpose-tags-down).

Semantic Database
=================

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 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 semantic-default-submodes (see Semantic mode).  You can also enable or disable SemanticDB with M-x global-semanticdb-minor-mode.

 -- Command: global-semanticdb-minor-mode
     Toggle SemanticDB mode.  When enabled, any source code parsed by semantic is cached in a database.

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

Semanticdb Tag Storage
----------------------

Each time you exit Emacs, any data cached by SemanticDB is saved in the directory .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 semanticdb-default-save-directory.

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

 -- Option: semanticdb-default-file-name
     The name of a cache file in which to save SemanticDB, when semanticdb-default-save-directory is nil.

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

 -- 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: never, always, or project.  The symbol never disables saving anywhere; always enables saving everywhere; and project enables saving directory based on the variable semanticdb-project-predicate-functions.

     The default value is (always).

 -- Variable: 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 semanticdb-persistent-path is (project).  If the list is empty, all paths are considered valid.

     Project management packages, such as EDE (see EDE manual), may add their own predicates with add-hook to this variable.  This allows SemanticDB to save tag caches in directories controlled by them.

 -- Option: semanticdb-save-database-functions
     Abnormal hook run after a database is saved.  Each function is called with one argument, the object representing the database recently written.

Semanticdb Search Configuration
-------------------------------

When another part of semantic (or another Emacs package using semantic) queries the SemanticDB library for a source code tag, the search need not be limited to tags defined within the current file. It can include tags defined elsewhere, such as header files referenced by the current file (e.g., via the C/C++ #include directive).  While performing the search, the SemanticDB library may even automatically visit other files and parse them, if necessary.

The variable semanticdb-find-default-throttle determines how aggressively SemanticDB searches for source code tags.  See Search Throttle.

The details of SemanticDB searches can vary from language to language.  In C/C++ code, for example, SemanticDB distinguishes between project header files and system header files, based on whether the #include directive uses the "" or <> filename delimiter.  SemanticDB looks for system header in the system include path (see Include paths).

SemanticDB Search Throttle
..........................

The SemanticDB search throttle determines how aggressive SemanticDB searches are.  It is controlled by the variable semanticdb-find-default-throttle.  The default value of this variable aims for maximum accuracy, at the expense of search time.

Other parts of the semantic package, particularly the different language parsers, may change the value of semanticdb-find-default-throttle.  You can override its value, for a given major mode, like this:

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

 -- Variable: semanticdb-find-default-throttle
     The default throttle for 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:

     file
          The file the search is being performed from.  This option is here for completeness only, and is assumed to always be on.

     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.

     project
          Tables from the same local project are included If project is specified, then local is assumed.

     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.

     system
          Tables from system databases.  These are specifically tables from system header files, or language equivalent.

     recursive
          For include based searches, includes tables referenced by included files.

     omniscience
          Included system databases which are omniscience, or somehow know everything.  Omniscience databases are found in semanticdb-project-system-databases.  The Emacs Lisp system DB is an omniscience database.

SemanticDB project roots
........................

The project setting in the SemanticDB search throttle (see Search Throttle) tells SemanticDB to search within the current single code project.  For semantic's point of view, projects are determined by their top-level directories, or project roots; every subdirectory of a project root is considered part of the same project.

If you use EDE for project management, it will set the project roots automatically.  See EDE manual.  You can also specify them yourself.

 -- Option: semanticdb-project-roots
     The value of this variable is a list of directories (strings) that are project roots.  All subdirectories of a project root are considered part of the same project.  This variable can be overridden by semanticdb-project-root-functions.

 -- Variable: 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 nil, a string (the project root), or a list of strings (multiple project roots, for complex systems).  The first non-nil return value, if any, is taken to be the project root, overriding semanticdb-project-roots.

Include Paths
.............

System include paths are standard locations to find source code tags, such as the header files in /usr/include and its subdirectories on Unix-like operating systems.

You can add and remove system include paths using the following commands:

 -- Command: semantic-add-system-include dir &optional mode
     Prompts for a directory, DIR, and add it as a system include path for the current major mode.  When called non-interactively, the major mode can be specified with the MODE argument.

 -- Command: semantic-remove-system-include dir &optional mode
     Prompt for a directory, DIR, and remove it from the system include path for the current major mode (or MODE).

 -- Command: semantic-customize-system-include-path &optional mode
     Customize the system include path for the current major mode (or MODE).

 -- Variable: semanticdb-implied-include-tags
     Include tags implied for all files of a given mode.  You can set this variable with defvar-mode-local for a particular mode so that any symbols that exist for all files for that mode are included.

Semanticdb search debugging commands
....................................

You can use M-x semanticdb-dump-all-table-summary to see the list of databases that will be searched from a given buffer.  You can follow up with M-x semanticdb-find-test-translate-path 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 M-x semanticdb-find-adebug-lost-includes.

 -- Command: semanticdb-dump-all-table-summary
     Dump a list of all databases in Emacs memory.

 -- Command: semanticdb-find-test-translate-path &optional arg
     Call and output results of semanticdb-find-translate-path.  In the displayed buffer, you can type SPC to expand items.  With ARG non-nil, specify a BRUTISH translation.

 -- Command: semanticdb-find-adebug-lost-includes
     Translate the current path, then display the lost includes. Examines the variable semanticdb-find-lost-includes.

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

 -- Command: semantic-adebug-searchdb regex
     Search the semanticdb for REGEX for the current buffer. Display the results as a debug list.

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.

 -- Variable: 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.

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.

 -- Command: semanticdb-create-ebrowse-database dir
     Create an Ebrowse database for directory DIR.  The database file is stored in ~/.semanticdb, or whichever directory is specified by semanticdb-default-system-save-directory.

Idle Scheduler
==============

The Semantic Idle Scheduler is a part of semantic that performs various operations while Emacs is waiting for user input (idle time).  Its primary job is to perform buffer parsing during idle time.  You can also use the Idle Scheduler to display function prototypes (see Idle Summary Mode) or symbol completions (see Idle Completions Mode).

 -- Command: global-semantic-idle-scheduler-mode &optional arg
     This command toggles Semantic Idle Scheduler mode in every semantic-enabled buffer.  This minor mode ensures that the buffer is automatically reparsed whenever Emacs is idle.  If there is additional idle time, it runs jobs scheduled by other parts of semantic, such as Semantic Idle Summary mode (see Idle Summary Mode) and Semantic Idle Completions mode (see Idle Completions Mode).

 -- Option: semantic-idle-scheduler-idle-time
     The value of this variable is the amount of idle time, in seconds, before the Semantic idle scheduler activates.  The default is 1.

 -- Option: semantic-idle-scheduler-verbose-flag
     If this variable is non-nil, the idle scheduler prints verbose messages while running, which are useful for debugging.

Reparsing Options
-----------------

When activated during idle time, the Semantic idle scheduler automatically reparses all buffers that need it.  Any arriving user input cancels this, returning Emacs to its normal editing behavior.

 -- Option: semantic-idle-scheduler-max-buffer-size
     Maximum size in bytes of buffers automatically reparsed.  If this value is less than or equal to 0, buffers are automatically reparsed regardless of their size.

 -- Option: semantic-idle-scheduler-no-working-message
     If non-nil, disable display of working messages while reparsing.

 -- Option: semantic-idle-scheduler-working-in-modeline-flag
     If non-nil, show working messages in the mode line.  Normally, re-parsing shows messages in the minibuffer; this moves the parse message to the modeline instead.

 -- Variable: semantic-before-idle-scheduler-reparse-hook
     This normal hook is run just before the idle scheduler begins reparsing.  If any hook function throws an error, the value of this variable is reset to nil.  This hook is not protected from lexical errors.

 -- Variable: semantic-after-idle-scheduler-reparse-hook

     This normal hook is run after the idle scheduler finishes reparsing. If any hook throws an error, this variable is reset to nil. This hook is not protected from lexical errors.

Idle Working Options
--------------------

In addition to reparsing buffers, the Semantic idle scheduler performs additional operations, including the following:

  * Creating the include path caches required for symbol lookup.

  * Create data type caches.

  * Saving SemanticDB caches to disk.

  * Speculatively parsing the files in the same directory as the current buffer.

Because this extra work is quite time-consuming, it is only carried out after a longer idle delay.  The following features control how the idle work is performed.

 -- Option: semantic-idle-scheduler-work-idle-time
     The value of this variable is the amount of idle time, in seconds, before commencing idle work.  The default is 60.

 -- Option: semantic-idle-work-parse-neighboring-files-flag
     If the value of this variable is non-nil, the Semantic idle scheduler uses idle work time to parse files in the same directory as the current buffer.  This improves the accuracy of tag searches and saves time when visiting those files later, at the cost of doing a lot of parsing.  The default is t.

Debugging Idle Time Issues
--------------------------

If you see an error signaled during idle time, it could be an indication of a more serious issue elsewhere.  It is not enough to enable debug-on-error, because the idle scheduler inhibits the debugger.  Instead, use the following commands to debug the error:

 -- Command: semantic-debug-idle-function
     Run the Semantic idle function with debugging turned on.

 -- Command: semantic-debug-idle-work-function
     Run the Semantic idle work function with debugging turned on.

Idle Summary Mode
-----------------

Semantic Idle Summary mode is a minor mode that displays a short summary of the symbol at point, such as its function prototype, in the echo area.  Its functionality is similar to what ElDoc mode provides for Emacs Lisp (see Lisp Doc (Emacs manual)).

 -- global-semantic-idle-summary-mode: &optional arg
     This command toggles Semantic Idle Summary mode in all semantic-enabled buffers.  You can also toggle it via the Show Tag Summaries menu item in the Development menu.

When Semantic Idle Summary mode is active, a summary of the tag at point is displayed in the echo area.  This display takes place during the idle time, as given by semantic-idle-scheduler-idle-time (see Idle Scheduler).

You can override the method for getting the current tag to display by setting idle-summary-current-symbol-info.

 -- Option: semantic-idle-summary-function
     The value of this variable should be a function to call to display tag information during idle time.  See the variable semantic-format-tag-functions for a list of useful functions.

 -- Variable: semantic-idle-summary-out-of-context-faces
     The value of this variable is a list of font-lock faces indicating useless summary contexts.  These are generally faces used to highlight comments or strings.  Semantic Idle Summary mode does not display its usual summary if the text at point has one of these faces.

Idle Completions Mode
---------------------

Semantic Idle Completions mode is a minor mode for performing code completions during idle time.  The completions are displayed inline, with keybindings that allow you to cycle through different alternatives.

Semantic Idle Completions mode performs completion based on the Semantic Analyzer (see Analyzer).

 -- global-semantic-idle-completions-mode: &optional arg
     This command toggles Semantic Idle Completions mode in every semantic-enabled buffer.  You can also toggle it via the Show Tag Completions menu item in the Development menu.

If the tag at point has at least one completion, Semantic Idle Completions mode displays that completion inline---i.e., as part of the buffer text (you can change the display method by customizing semantic-complete-inline-analyzer-idle-displayer-class, as described below).  The completed part is highlighted, to indicate that it is not yet properly inserted into the buffer.  The echo area shows the completion, and whether there are other possible completions, like this:

     besselj [1 of 6 matches]

While the completion is being displayed, the following keybindings take effect:

RET
C-m
     Accept the current completion (semantic-complete-inline-done), placing it in the buffer and moving point to the end of the completed tag.

M-n
     Select the next possible completion (semantic-complete-inline-down).  The new completion is shown inline, replacing the old completion.

M-p
     Select the previous possible completion (semantic-complete-inline-up).

TAB

C-i
     Accept as much of the completion as possible.  If no additional completion can be accepted without ambiguity, select the next possible completion (semantic-complete-inline-TAB).

C-g
     Quit without completing (semantic-complete-inline-quit).

You can also exit inline completion by issuing any other Emacs command.  The completion text then disappears from the buffer.

 -- Command: semantic-complete-analyze-inline-idle
     This is the command for performing inline code completion.  It is called by Semantic Idle Completions mode during idle time, but you can also call it yourself.  It returns immediately, leaving the buffer in a state for inline completion.

 -- Option: semantic-complete-inline-analyzer-idle-displayer-class
     The value of this variable determines how semantic-complete-analyze-inline-idle shows its completions. Possible values include:

     semantic-displayer-ghost
          Display completions ``inline'' with the buffer text, as described above.  This is the default value.

     semantic-displayer-tooltip
          Display completions in a tooltip.

     semantic-displayer-traditional
          Display completions in a separate window.

Analyzer
========

The Semantic Analyzer is a library for performing context analysis on source code.  It provides user commands for displaying, completing, and navigating through source code.

Smart Completion
----------------

The Semantic Analyzer can be used to perform code completion in a manner that takes the local context into account.  (In addition to the user commands in this section, Semantic Idle Completions mode also uses the Semantic Analyzer.  See Idle Completions Mode.)

 -- Command: semantic-analyze-possible-completions context
     This is the most basic command for Semantic Analyzer-based completion. Called interactively, it displays a list of the possible completions for the symbol at point.

     When called from a Lisp program, semantic-analyze-possible-completions does not display a completions list.  The argument CONTEXT should be either a buffer position, or a context object.  The return value is a list of semantic tag objects that complete the symbol for CONTEXT, based on the following criteria:

       * Elements currently in scope.

       * Constants currently in scope.

       * Elements matching the context's :prefix.

       * Type of the completion matching the type of the context.

     Most of the other commands documented in this section call semantic-analyze-possible-completions internally.

 -- Command: semantic-complete-analyze-inline
     This command is bound to C-c , SPC when Semantic mode is enabled (see Semantic mode user commands).  It displays a list of possible completions for the symbol at point, and activates a special set of keybindings for choosing a completion.

     You can type RET to accept the current completion, M-n and M-p to cycle through the possible completions, TAB to complete as far as possible and then cycle through completions, and either C-g or any other key to abort the completion.

     This command is similar to the completion performed by Semantic Idle Completions mode.  The main difference is that it is called explicitly, whereas Semantic Idle Completions mode completes during idle time (see Idle Completions Mode).

 -- Option: semantic-complete-inline-analyzer-idle-displayer-class
     The value of this variable determines how semantic-complete-analyze-inline shows its completions. Possible values include:

     semantic-displayer-traditional
          Display completions in a separate window.  This is the default value.

     semantic-displayer-ghost
          Display completions ``inline'' with the buffer text, similar to the default behavior of Semantic Idle Completions mode (see Idle Completions Mode).

     semantic-displayer-tooltip
          Display completions in a tooltip.

In addition to semantic-complete-analyze-inline, you can use the simpler command semantic-ia-complete-symbol point.  This behaves like the usual M-TAB (complete-symbol) command (see Symbol Completion (Emacs manual)), except it uses the Semantic Analyzer.

 -- Command: semantic-ia-complete-symbol point
     Complete the current symbol at POINT.

Smart Summary
-------------

You can use the following commands to obtain information about the code at point:

 -- Command: semantic-ia-show-summary pos
     Display a summary for the symbol at POS.  Called interactively, POS defaults to point.

 -- Command: semantic-ia-show-doc pos
     Display the code-level documentation for the symbol at POS. Called interactively, POS defaults to point.

 -- Command: semantic-ia-describe-class typename
     Prompt for the name of a data type, TYPENAME, and display its components.  For instance, if the type in question is a class, this displays the methods and member variables.

You can also use Semantic Idle Summary mode to show information about the current symbol in the echo area during idle time.  See Idle Summary Mode.

Smart Jump
----------

The Semantic Analyzer can be used to jump directly to the definition for a code symbol.

 -- Command: semantic-ia-fast-jump pos
     Jump to the definition for the symbol at POS.  Called interactively, POS defaults to point.

 -- Function: semantic-ia-fast-mouse-jump event
     Jump to the definition for the symbol at the position of the mouse event EVENT.  This command is meant to be bound to a mouse command, like this:

          (global-set-key '[(S-mouse-1)] semantic-ia-fast-mouse-jump)

These commands are often more accurate than the xref-find-definitions command (see Looking Up Identifiers (Emacs manual)), because the Semantic Analyzer is context-sensitive.

You can also use C-c , j (semantic-complete-jump-local) and C-c , J (semantic-complete-jump) to navigate tags. See Semantic mode user commands.  Those commands do not make use of the Semantic Analyzer.

Debugging the Semantic Analyzer
-------------------------------

If the Semantic Analyzer does not analyze your code properly, you can take steps to identify and solve the problem.  This section was written with C/C++ in mind, but should be relevant for any typed language.

Step 1: Check the context
.........................

To check the current context, type M-x semantic-analyze-current-context.

 -- Command: semantic-analyze-current-context pos
     Analyze the context at POS.  This function is used by most of the other Semantic Analyzer commands to obtain the context of the code at a given buffer position.  The return value is an EIEIO object describing the context at POS (see EIEIO manual).

     When called interactively, this displays a *Semantic Context Analysis* buffer containing a summary of the context at point.

The Prefix section of the *Semantic Context Analysis* buffer lists the tags based on the text at point.  If it shows only a simple string, the Semantic was unable to identify what the data type was.

The first item in the list of the prefix is the first lookup failure in the chain, and that is the item to focus debugging effort on.  For example:

     Context Type: #<semantic-analyze-context context>
     Bounds: (182 . 185)
     Prefix: Foo* bar
             int bbb (const char* y)
     Prefix Types: class Foo {}
     --------
     -> Local Vars: int argc
                    char** argv

In this example you can see that the prefix has two fully found tags. In the following example, the symbol ``bbb'' is incomplete, and could not be found:

     Context Type: #<semantic-analyze-context context>
     Bounds: (182 . 184)
     Prefix: Foo* bar
             "bb"
     Prefix Classes: 'function
                     'variable
     Prefix Types: class Foo {}
     --------
     -> Local Vars: int argc
                    char** argv

Step 2 : Check your include path
................................

Once you know the missing symbol, check your include path.  The header or include file containing the needed definition may not be in the list of headers semantic is searching through.  To get a basic list, you can use M-x semanticdb-find-test-translate-path. See Semanticdb search debugging commands.

If items should be loaded but aren't, or if you see some tables that have no tags in them, then you may have an incorrectly-set search throttle (see Search Throttle).  For example,

     *#<semanticdb-table main.cpp (4 tags DIRTY)>
     *#<semanticdb-table foo.hh (0 tags DIRTY)>

Here, semantic found foo.hh, but there are 0 tags.  This may be because you had set the throttle to avoid reading and parsing files that Emacs has not visited.  To fix this, visit the file and let semantic parse it.

For C++, check also that the #include statements for your project-level files use quotes, not angle brackets; angle brackets are for system files.

Step 3: Check the local scope
.............................

If your data type is somehow abbreviated based on scope, such as from a using statement, you should make sure that the symbol you want is in the local scope.  Examine the scope with M-x semantic-calculate-scope.  The scope structure is displayed in ADEBUG mode, so use SPC to expand different elements and looking for your symbol.

If your symbol should be in the scope, but you cannot find it, then you may have found a language support bug in the local-variable parser, or using statement parser.

Calling M-x bovinate should force a reset on the scope in case there is merely some bad state.

      ] Name: Cache
      ] Class: #'semantic-scope-cache
      ] :table #<semanticdb-table testsubclass.cpp (13 tags DIRTY)>
      ] tag createMoose : class moose
      ] scopetypes 'nil
      ] parents #<TAG LIST: 1 entries>
      ] scope #<TAG LIST: 22 entries>
      ] fullscope #<TAG LIST: 23 entries>
      ] localvar #<TAG LIST: 6 entries>

In the above sample output, the tag slot specifies where within you source this scope is relevant.  Parents should contain any in scope parents, such as the class a method belongs to. Localvar should contain your local variables.  Scope should contain datatypes in scope due to a using statement or the like.

Step 4: Check the typecache
...........................

For complex typed languages like C++, semantic creates a typecache, or an optimized search table with all the various data types in it. Elements in the typecache do not obey local scope.  It only contains fully qualified names.  You can examine the typecache with M-x semanticdb-typecache-dump.

If your data types are not in the typecache, there may be some parsing error or other bug.  Calling M-x bovinate should force a reset on the typecache in case there is merely some bad state.

     ]#<semanticdb-typecache /home/zappo/cedet/semantic/tests/testsubclass.cpp>
        ] Name: /home/zappo/cedet/semantic/tests/testsubclass.cpp
        ] Class: #'semanticdb-typecache
        ] filestream 'nil
        ] includestream #<TAG LIST: 84 entries>
        ] stream 'nil
        ] dependants 'nil

In the above example, the output of M-x semanticdb-typecache-dump was expanded one level.  The filestream slot should contain datatypes in the current file.  The includestream should contain all the datatypes in all included header files.

The dependants slot will specify other files that depend on this one.

Step 5: Check the parser
........................

Go to the location where your unfound tag should be.  You can call M-x bovinate, and see a dump of the raw tag structure.  To see a navigable tree, use M-x semantic-adebug-bovinate instead.  You can then look to make sure your tag has been properly parsed.

If it has not, then you may have found a parser bug.  To get a feel how semantic treats your file, type M-x global-semantic-show-unmatched-syntax-mode.  This causes any syntax it cannot parse to be underlined in red.

If your type is not parsable, it could be for a couple of reasons:

 1. If there is a MACRO keyword used in the definition of the type, you may need to update the semantic-lex-c-preprocessor-symbol-map to account for it.

 2. Or perhaps the parser needs to be fixed.

Speedbar
========

You can integrate semantic with the Speedbar. See Speedbar (Emacs manual).  To do this, add the following line to your init file:

     (add-hook 'speedbar-load-hook (lambda () (require 'semantic/sb)))

Or, alternatively:

     (require 'semantic/sb)

Once installed, the Speedbar will use semantic to find and display tags.  Tags from semantic are displayed with more details than ordinary Speedbar tags, such as function arguments and return type.

In addition, you can use the Speedbar to show the output of the Semantic Analyzer (see Analyzer).  To do this, go to the Display menu item on the Speedbar menu and select Analyze; or type M-x semantic-speedbar-analysis.

 -- Command: semantic-speedbar-analysis
     Start the Speedbar in Semantic Analysis mode.

In Semantic Analysis mode, the Speedbar displays information about the local context, such as the current function, local arguments and variables, and details on the prefix (the current symbol).  Each entry has an <i> button; clicking on this shows a summary of what semantic knows about that variable or type.  The Speedbar also displays a list of possible completions at point.

Symbol References
=================

semantic can interface with external symbol reference tools, such as GNU Global and GNU Idutils.  These tools provide information about where different tags or symbols appear.

By default, semantic tries to look for the best external symbol reference tool that can be used.  The supported tools are GNU Global, GNU Idutils, CScope, and Grep (the fallback method).  For best results, use GNU Global.  However, semantic does not manage your GNU Global tables for you; you must manage them yourself.

 -- Variable: semantic-symref-tool
     The value of this variable is a symbol that determines the external symbol reference tool to use.  The default value, detect, says to look for the best available tool.  Other possible values are global, idutils, cscope, and grep.  Note that grep is much slower than the others.

The commands to display symbol references are C-c , g (semantic-symref-symbol and C-c , G (semantic-symref).  These keybindings are available whenever Semantic mode is enabled (see Semantic mode user commands).

 -- Command: semantic-symref-symbol sym
     This command (normally bound to C-c , g) prompts for a symbol name, and uses an external reference tool to find references to that tag.

 -- Command: semantic-symref
     This command (normally bound to C-c , G) uses an external reference tool to find references to the current tag.

Both semantic-symref-symbol and semantic-symref display a list of symbol references in a separate buffer.  The entries are organized by file, and by function name.  Typing RET on the [+] next to each function name ``expands'' that entry, listing all references to the target symbol occurring within that function. Typing RET on a reference line jumps to that reference.

MRU Bookmarks mode
==================

Semantic MRU Bookmarks mode is a minor mode that keeps track of the tags you have edited, allowing you to quickly return to them later (MRU stands for ``Most Recently Used'').

 -- Command: global-semantic-mru-bookmark-mode &optional arg
     Toggle Semantic MRU Bookmarks mode globally.  The minor mode can be turned on only if the current buffer was set up for parsing.  With argument ARG, turn the minor mode if ARG is positive, and off otherwise.

Semantic MRU Bookmarks mode takes note of each tag you edit. Afterwards, you can type C-x B (semantic-mrub-switch-tags) to return to a tag.  This command prompts for a tag name, completing with the names of edited tags; at the prompt, you can use M-p and M-n to cycle through tags in order of last modification time.

Sticky Function mode
====================

Semantic Sticky Function minor mode displays a header line that shows the declaration line of the function or tag on the topmost line in the text area.  This allows you to keep that declaration line in view at all times, even if it is scrolls off the ``top'' of the screen.

In addition, clicking mouse-1 on the header line opens a context menu that contains menu items for copying, killing, or narrowing to that tag.

 -- Command: global-semantic-stickyfunc-mode &optional arg
     Toggle Semantic Sticky Function mode in all Semantic-enabled buffers. With an optional argument ARG, enable if ARG is positive, and disable otherwise.

 -- Variable: semantic-stickyfunc-sticky-classes
     The value of this variable is a list of tag classes that Semantic Sticky Function mode makes ``sticky''.  The default is '(function type), meaning function declarations and type declarations.  Other possible tag classes are variable, include, and package.

Highlight Func Mode
===================

Semantic Highlight Function minor mode highlights the declaration line of the current function or tag (that is to say, the first line that describes the rest of the construct).

In addition, clicking mouse-3 on the highlighted declaration line opens a context menu that contains menu items for copying, killing, or narrowing to that tag.

The tag classes highlighted by Semantic Highlight Function mode are the same ones given by semantic-stickyfunc-sticky-classes. See Sticky Func Mode.

 -- Function: global-semantic-highlight-func-mode &optional arg
     Toggle Semantic Highlight Function mode in all Semantic-enabled buffers.  With an optional argument ARG, enable if ARG is positive, and disable otherwise.

 -- Face: semantic-highlight-func-current-tag-face
     This face is used to highlight declaration lines in Semantic Highlight Func mode.

Tag Decoration Mode
===================

Semantic Tag Decoration mode ``decorates'' each tag based on certain arbitrary features of that tag.  Decorations are specified using the variable semantic-decoration-styles.

 -- Command: global-semantic-decoration-mode &optional arg
     Toggle Semantic Tag Decoration mode in all Semantic-enabled buffers. With an optional argument ARG, enable if ARG is positive, and disable otherwise.

 -- Variable: semantic-decoration-styles
     The value of this variable is a list of decoration styles for Semantic Tag Decoration mode.  Each element in this list should have the form (NAME . FLAG), where NAME is a style name (a symbol) and FLAG is non-nil if the style is enabled.

     The following styles are available:

     semantic-tag-boundary
          Place an overline in front of each long tag (excluding prototypes).

     semantic-decoration-on-private-members
          Highlight class members that are designated as private.

     semantic-decoration-on-protected-members
          Highlight class members that are designated as protected.

     semantic-decoration-on-includes
          Highlight class members that are includes.  Clicking on the highlighted include statements opens a context menu for configuring semantic includes.

To enable or disable specific decorations, use this function:

 -- Command: semantic-toggle-decoration-style name &optional arg
     Prompt for a decoration style, NAME, and turn it on or off. With prefix argument ARG, turn on if positive, otherwise off. Return non-nil if the decoration style is enabled.

 -- Face: semantic-tag-boundary-face
     Face for long tags in the semantic-tag-boundary decoration style.

 -- Face: semantic-decoration-on-private-members-face
     Face for privately-scoped tags in the semantic-decoration-on-private-members decoration style.

 -- Face: semantic-decoration-on-protected-members-face
     Face for protected tags in the semantic-decoration-on-protected-members decoration style.

 -- Face: semantic-decoration-on-includes
     Face for includes that are not in some other state, in the semantic-decoration-on-includes decoration style.

 -- Face: semantic-decoration-on-unknown-includes
     Face for includes that cannot be found, in the semantic-decoration-on-includes decoration style.

 -- Face: semantic-decoration-on-unparsed-includes
     Face for includes that have not yet been parsed, in the semantic-decoration-on-includes decoration style.

Creating New Decoration Modes
-----------------------------

You can create new types of decorations using the following function:

 -- Function: define-semantic-decoration-style name doc &rest flags
     Define a new decoration style with NAME. DOC is a documentation string describing the decoration style NAME. It is appended to auto-generated doc strings. An optional list of FLAGS can also be specified.  Flags are: :enabled <value>  - specify the default enabled value for NAME.

     This defines two new overload functions respectively called NAME-p and NAME-highlight, for which you must provide a default implementation in respectively the functions NAME-p-default and NAME-highlight-default.  Those functions are passed a tag.  NAME-p must return non-nil to indicate that the tag should be decorated by NAME-highlight.

     To put primary decorations on a tag NAME-highlight, use functions like semantic-set-tag-face, semantic-set-tag-intangible, etc., found in the semantic-decorate library.

     To add other kind of decorations on a tag, NAME-highlight must use semantic-decorate-tag, and other functions of the semantic decoration API found in this library.