*** empty log message ***

[gnu-emacs] / etc / DEBUG

diff --git a/etc/DEBUG b/etc/DEBUG
index abb49143a0574b7ea71072081d8e80d15c024c69..a29e5fd3e6c1fd23b26e8967c24bfa6d743b4737 100644 (file)
--- a/etc/DEBUG
+++ b/etc/DEBUG
@@ -1,5 +1,5 @@
 Debugging GNU Emacs
-Copyright (c) 1985, 2000, 2001 Free Software Foundation, Inc.
+Copyright (c) 1985, 2000, 2001, 2005 Free Software Foundation, Inc.
 
    Permission is granted to anyone to make or distribute verbatim copies
    of this document as received, in any medium, provided that the
@@ -17,8 +17,15 @@ should read the Windows-specific section near the end of this
 document.]
 
 ** When you debug Emacs with GDB, you should start it in the directory
-where you built Emacs.  That directory has a .gdbinit file that defines
-various "user-defined" commands for debugging Emacs.
+where the executable was made.  That directory has a .gdbinit file
+that defines various "user-defined" commands for debugging Emacs.
+
+** When you are trying to analyze failed assertions, it will be
+essential to compile Emacs either completely without optimizations or
+at least (when using GCC) with the -fno-crossjumping option.  Failure
+to do so may make the compiler recycle the same abort call for all
+assertions in a given function, rendering the stack backtrace useless
+for identifying the specific failed assertion.
 
 ** It is a good idea to run Emacs under GDB (or some other suitable
 debugger) *all the time*.  Then, when Emacs crashes, you will be able
@@ -62,6 +69,11 @@ use the set command until the inferior process has been started.
 Put a breakpoint early in `main', or suspend the Emacs,
 to get an opportunity to do the set command.
 
+When Emacs is running in a terminal, it is useful to use a separate terminal
+for the debug session.  This can be done by starting Emacs as usual, then
+attaching to it from gdb with the `attach' command which is explained in the
+node "Attach" of the GDB manual.
+
 ** Examining Lisp object values.
 
 When you have a live process to debug, and it has not encountered a
@@ -115,7 +127,7 @@ called frame.  First, use these commands:
     b set_frame_buffer_list
     r -q
 
-Then when Emacs it hits the breakpoint:
+Then Emacs hits the breakpoint:
 
     (gdb) p frame
     $1 = 139854428
@@ -564,6 +576,13 @@ these data structures on the respective headers to remove the `:N'
 bitfield definitions (which will cause each such field to use a full
 int).
 
+** How to recover buffer contents from an Emacs core dump file
+
+The file etc/emacs-buffer.gdb defines a set of GDB commands for
+recovering the contents of Emacs buffers from a core dump file.  You
+might also find those commands useful for displaying the list of
+buffers in human-readable format from within the debugger.
+
 ** Some suggestions for debugging on MS Windows:
 
    (written by Marc Fleischeuers, Geoff Voelker and Andrew Innes)