@c This is part of the Emacs manual.
-@c Copyright (C) 1985-1987, 1993-1995, 1997, 2000-2012
-@c Free Software Foundation, Inc.
+@c Copyright (C) 1985-1987, 1993-1995, 1997, 2000-2015 Free Software
+@c Foundation, Inc.
@c See file emacs.texi for copying conditions.
@node Building
@chapter Compiling and Testing Programs
was started.
@findex kill-compilation
+@vindex compilation-always-kill
Starting a new compilation also kills any compilation already
running in @file{*compilation*}, as the buffer can only handle one
compilation at any time. However, @kbd{M-x compile} asks for
-confirmation before actually killing a compilation that is running.
-You can also kill the compilation process with @kbd{M-x
+confirmation before actually killing a compilation that is running; to
+always automatically kill the compilation without asking, change the
+variable @code{compilation-always-kill} to @code{t}. You can also
+kill a compilation process with the command @kbd{M-x
kill-compilation}.
To run two compilations at once, start the first one, then rename
@findex next-error-follow-minor-mode
You can type @kbd{C-c C-f} to toggle Next Error Follow mode. In
this minor mode, ordinary cursor motion in the compilation buffer
-automatically updates the source buffer, i.e.@: moving the cursor over
+automatically updates the source buffer, i.e., moving the cursor over
an error message causes the locus of that error to be displayed.
The features of Compilation mode are also available in a minor mode
@ifnottex
On the MS-DOS ``operating system'', asynchronous subprocesses are
not supported, so @kbd{M-x compile} runs the compilation command
-synchronously (i.e.@: you must wait until the command finishes before
+synchronously (i.e., you must wait until the command finishes before
you can do anything else in Emacs). @xref{MS-DOS}.
@end ifnottex
@findex gud-tooltip-mode
@vindex gud-tooltip-echo-area
GUD Tooltip mode is a global minor mode that adds tooltip support to
-GUD. To toggle this mode, type @kbd{M-x gud-tooltip-mode}. It is
+GUD@. To toggle this mode, type @kbd{M-x gud-tooltip-mode}. It is
disabled by default. If enabled, you can move the mouse cursor over a
-variable to show its value in a tooltip (@pxref{Tooltips}); this takes
-effect in the GUD interaction buffer, and in all source buffers with
-major modes listed in the variable @code{gud-tooltip-modes}. If the
-variable @code{gud-tooltip-echo-area} is non-@code{nil}, values are
-shown in the echo area instead of a tooltip.
-
- When using GUD Tooltip mode with @kbd{M-x gud-gdb}, you should note
-that displaying an expression's value in GDB can sometimes expand a
-macro, potentially causing side effects in the debugged program. If
-you use the @kbd{M-x gdb} interface, this problem does not occur, as
-there is special code to avoid side-effects; furthermore, you can
-display macro definitions associated with an identifier when the
-program is not executing.
+variable, a function, or a macro (collectively called
+@dfn{identifiers}) to show their values in tooltips
+(@pxref{Tooltips}). Alternatively, mark an identifier or an
+expression by dragging the mouse over it, then leave the mouse in the
+marked area to have the value of the expression displayed in a
+tooltip. The GUD Tooltip mode takes effect in the GUD interaction
+buffer, and in all source buffers with major modes listed in the
+variable @code{gud-tooltip-modes}. If the variable
+@code{gud-tooltip-echo-area} is non-@code{nil}, or if you turned off
+the tooltip mode, values are shown in the echo area instead of a
+tooltip.
+
+ When using GUD Tooltip mode with @kbd{M-x gud-gdb}, displaying an
+expression's value in GDB can sometimes expand a macro, potentially
+causing side effects in the debugged program. For that reason, using
+tooltips in @code{gud-gdb} is disabled. If you use the @kbd{M-x gdb}
+interface, this problem does not occur, as there is special code to
+avoid side-effects; furthermore, you can display macro definitions
+associated with an identifier when the program is not executing.
@node Commands of GUD
@subsection Commands of GUD
selecting stack frames, and stepping through the program.
@table @kbd
-@item C-x @key{SPC}
-@kindex C-x SPC
+@item C-x C-a C-b
+@kindex C-x C-a C-b
Set a breakpoint on the source line that point is on.
@end table
- @kbd{C-x @key{SPC}} (@code{gud-break}), when called in a source
+ @kbd{C-x C-a C-b} (@code{gud-break}), when called in a source
buffer, sets a debugger breakpoint on the current source line. This
-command is available only after starting GUD. If you call it in a
+command is available only after starting GUD@. If you call it in a
buffer that is not associated with any debugger subprocess, it signals
a error.
that makes sense.
Because @key{TAB} serves as a completion command, you can't use it to
-enter a tab as input to the program you are debugging with GDB.
+enter a tab as input to the program you are debugging with GDB@.
Instead, type @kbd{C-q @key{TAB}} to enter a tab.
@node GUD Customization
you are using DBX; @code{sdb-mode-hook}, if you are using SDB;
@code{xdb-mode-hook}, if you are using XDB; @code{perldb-mode-hook},
for Perl debugging mode; @code{pdb-mode-hook}, for PDB;
-@code{jdb-mode-hook}, for JDB. @xref{Hooks}.
+@code{jdb-mode-hook}, for JDB@. @xref{Hooks}.
The @code{gud-def} Lisp macro (@pxref{Defining Macros,,, elisp, the
Emacs Lisp Reference Manual}) provides a convenient way to define an
@end group
@end smallexample
- However, if @code{gdb-use-separate-io-buffer} is @code{nil}, the I/O
-buffer does not appear and the primary source buffer occupies the full
-width of the frame.
-
@findex gdb-restore-windows
@findex gdb-many-windows
If you ever change the window layout, you can restore the ``many
The GDB Threads buffer displays a summary of the threads in the
debugged program. @xref{Threads, Threads, Debugging programs with
multiple threads, gdb, The GNU debugger}. To select a thread, move
-point there and type @key{RET} (@code{gdb-select-thread}), or click on
+point there and press @key{RET} (@code{gdb-select-thread}), or click on
it with @kbd{Mouse-2}. This also displays the associated source
buffer, and updates the contents of the other GDB buffers.
@code{gdb-switch-reasons} to select the stop reasons which will cause
a thread switch.
-@vindex gdb-stopped-hooks
- The variable @code{gdb-stopped-hooks} allows you to execute your
+@vindex gdb-stopped-functions
+ The variable @code{gdb-stopped-functions} allows you to execute your
functions whenever some thread stops.
In non-stop mode, you can switch between different modes for GUD
@findex load
@findex load-library
+@vindex load-prefer-newer
@cindex load path for Emacs Lisp
If an Emacs Lisp file is installed in the Emacs Lisp @dfn{load path}
(defined below), you can load it by typing @kbd{M-x load-library},
searches through each directory in the Emacs Lisp load path, trying to
find a file matching that library name. If the library name is
@samp{@var{foo}}, it tries looking for files named
-@file{@var{foo}.elc}, @file{@var{foo}.el}, and lastly just
-@file{@var{foo}}; the first one found is loaded. This command prefers
-@file{.elc} files over @file{.el} files because compiled files load
-and run faster. If it finds that @file{@var{lib}.el} is newer than
-@file{@var{lib}.elc}, it issues a warning, in case someone made
+@file{@var{foo}.elc}, @file{@var{foo}.el}, and @file{@var{foo}}. The
+default behavior is to load the first file found. This command
+prefers @file{.elc} files over @file{.el} files because compiled files
+load and run faster. If it finds that @file{@var{lib}.el} is newer
+than @file{@var{lib}.elc}, it issues a warning, in case someone made
changes to the @file{.el} file and forgot to recompile it, but loads
the @file{.elc} file anyway. (Due to this behavior, you can save
unfinished edits to Emacs Lisp source files, and not recompile until
-your changes are ready for use.)
+your changes are ready for use.) If you set the option
+@code{load-prefer-newer} to a non-@code{nil} value, however, then
+rather than the procedure described above, Emacs loads whichever
+version of the file is newest.
Emacs Lisp programs usually load Emacs Lisp files using the
@code{load} function. This is similar to @code{load-library}, but is
@end example
@cindex autoload
- Some commands are @dfn{autoloaded}: when you run them, Emacs
+ Some commands are @dfn{autoloaded}; when you run them, Emacs
automatically loads the associated library first. For instance, the
@kbd{M-x compile} command (@pxref{Compilation}) is autoloaded; if you
call it, Emacs automatically loads the @code{compile} library first.
In contrast, the command @kbd{M-x recompile} is not autoloaded, so it
is unavailable until you load the @code{compile} library.
+@vindex help-enable-auto-load
+ Automatic loading can also occur when you look up the documentation
+of an autoloaded command (@pxref{Name Help}), if the documentation
+refers to other functions and variables in its library (loading the
+library lets Emacs properly set up the hyperlinks in the @file{*Help*}
+buffer). To disable this feature, change the variable
+@code{help-enable-auto-load} to @code{nil}.
+
@vindex load-dangerous-libraries
@cindex Lisp files byte-compiled by XEmacs
By default, Emacs refuses to load compiled Lisp files which were
@section Evaluating Emacs Lisp Expressions
@cindex Emacs Lisp mode
@cindex mode, Emacs Lisp
+@cindex evaluation, Emacs Lisp
@findex emacs-lisp-mode
Emacs Lisp mode is the major mode for editing Emacs Lisp. Its mode
The command @kbd{C-x C-e} (@code{eval-last-sexp}) evaluates the
Emacs Lisp expression preceding point in the buffer, and displays the
value in the echo area. When the result of an evaluation is an
-integer, you can type @kbd{C-x C-e} a second time to display the value
-of the integer result in additional formats (octal, hexadecimal, and
-character).
+integer, it is displayed together with the value in other formats
+(octal, hexadecimal, and character).
If @kbd{M-:} or @kbd{C-x C-e} is given a prefix argument, it inserts
the value into the current buffer at point, rather than displaying it
-in the echo area. The argument's value does not matter.
+in the echo area. If the prefix argument is zero, any integer output
+is inserted together with its value in other formats (octal,
+hexadecimal, and character). Such a prefix argument also prevents
+abbreviation of the output according to the variables
+@code{eval-expression-print-level} and @code{eval-expression-print-length}
+(see below).
@kindex C-M-x @r{(Emacs Lisp mode)}
@findex eval-defun
The options @code{eval-expression-print-level} and
@code{eval-expression-print-length} control the maximum depth and
length of lists to print in the result of the evaluation commands
-before abbreviating them. @code{eval-expression-debug-on-error}
-controls whether evaluation errors invoke the debugger when these
-commands are used; its default is @code{t}.
+before abbreviating them. Supplying a zero prefix argument to
+@code{eval-expression} or @code{eval-last-sexp} causes lists to be
+printed in full. @code{eval-expression-debug-on-error} controls
+whether evaluation errors invoke the debugger when these commands are
+used; its default is @code{t}.
@node Lisp Interaction
@section Lisp Interaction Buffers