diff options
Diffstat (limited to 'doc/lispref/debugging.texi')
| -rw-r--r-- | doc/lispref/debugging.texi | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/doc/lispref/debugging.texi b/doc/lispref/debugging.texi index 469ff2d943d..058c9319544 100644 --- a/doc/lispref/debugging.texi +++ b/doc/lispref/debugging.texi @@ -196,6 +196,17 @@ echo area. For example, this can be useful when trying to find the cause of a particular message. @end defvar +@defvar debug-allow-recursive-debug +You can evaluate forms in the current stack frame in the +@samp{*Backtrace*} buffer with the @key{e} command, and while +edebugging you can use the @key{e} and @key{C-x C-e} commands to do +something similar. By default, the debugger is inhibited by these +commands (because (re-)entering the debugger at this point will +usually take you out of the debugging context you're in). Set +@code{debug-allow-recursive-debug} to a non-@code{nil} value to allow +these commands to enter the debugger recursively. +@end defvar + To debug an error that happens during loading of the init file, use the option @samp{--debug-init}. This binds @code{debug-on-error} to @code{t} while loading the init file, and @@ -387,11 +398,9 @@ possibilities.) variable is temporarily set according to @code{eval-expression-debug-on-error}. If the latter variable is non-@code{nil}, @code{debug-on-error} will temporarily be set to -@code{t}. This means that any further errors that occur while doing a -debugging session will (by default) trigger another backtrace. If -this is not what you want, you can either set -@code{eval-expression-debug-on-error} to @code{nil}, or set -@code{debug-on-error} to @code{nil} in @code{debugger-mode-hook}. +@code{t}. However, further errors that occur while debugging won't +(by default) trigger another debugger, because @code{inhibit-debugger} +will also be bound to non-@code{nil}. The debugger itself must be run byte-compiled, since it makes assumptions about the state of the Lisp interpreter. These @@ -522,6 +531,7 @@ Flag the current frame like @kbd{b}. Then continue execution like @kbd{c}, but temporarily disable break-on-entry for all functions that are set up to do so by @code{debug-on-entry}. +@vindex debug-allow-recursive-debug @item e Read a Lisp expression in the minibuffer, evaluate it (with the relevant lexical environment, if applicable), and print the @@ -530,7 +540,11 @@ variables, and the current buffer, as part of its operation; @kbd{e} temporarily restores their values from outside the debugger, so you can examine and change them. This makes the debugger more transparent. By contrast, @kbd{M-:} does nothing special in the debugger; it shows you -the variable values within the debugger. +the variable values within the debugger. By default, this command +suppresses the debugger during evaluation, so that an error in the +evaluated expression won't add a new error on top of the existing one. +Set the @code{debug-allow-recursive-debug} user option to a +non-@code{nil} value to override this. @item R Like @kbd{e}, but also save the result of evaluation in the |