* DEBUG: Document -Og.

diff --git a/etc/ChangeLog b/etc/ChangeLog
index f80c1b6973cae4e64edc768367c2f691f0d5fb54..e7fdc25be51ee4f855fe3a933f0fa6afe31ed0e4 100644 (file)
--- a/etc/ChangeLog
+++ b/etc/ChangeLog
@@ -1,3 +1,7 @@
+2013-06-13  Paul Eggert  <eggert@cs.ucla.edu>
+
+       * DEBUG: Document -Og.
+
 2013-06-05  Teodor Zlatanov  <tzz@lifelogs.com>
 
        * NEWS: Document new prog-mode symbol prettify support.

diff --git a/etc/DEBUG b/etc/DEBUG
index 709e8987d03639584702bd7a83cacd1f51865ada..a76a60641c9dd02f000defda7a66a915f5eb64ce 100644 (file)
--- a/etc/DEBUG
+++ b/etc/DEBUG
@@ -24,8 +24,10 @@ There are several ways to overcome that difficulty, they are all
 described in the node "Auto-loading safe path" in the GDB user manual.
 
 ** When you are trying to analyze failed assertions or backtraces, it
-will be essential to compile Emacs either completely without
-optimizations (set CFLAGS to "-O0 -g3") or at least (when using GCC)
+is essential to compile Emacs with flags suitable for debugging.
+With GCC 4.8 or later, you can invoke 'make' with CFLAGS="-Og -g3".
+With older GCC or non-GCC commpilers, you can use CFLAGS="-O0 -g3".
+With GCC and higher optimization levels such as -O2, at least compile
 with the -fno-crossjumping option in CFLAGS.  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
@@ -769,4 +771,3 @@ Local variables:
 mode: outline
 paragraph-separate: "[         \f]*$"
 end:
-