From 187be4adee9642aa3d3409cd036a4345c84aae6b Mon Sep 17 00:00:00 2001
From: Dave Allison <dallison@google.com>
Date: Mon, 8 Sep 2014 16:33:24 -0700
Subject: [PATCH 1/2] Add support for debugging ART to the dalvik.gdb script.

This adds two commands:

art-on
art-off

To the gdbclient script for debugging ART-based executables in gdb.
The default is 'art-on'

Bug: 17409881
Change-Id: I90a1aed603e50853a40d5f5ec1c9b168dc17ddc7
(cherry picked from commit 22382a4774d7e7b34cc28082cbe76e58ce48a44b)
---
 scripts/gdb/dalvik.gdb | 59 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/scripts/gdb/dalvik.gdb b/scripts/gdb/dalvik.gdb
index cab0951d7..6ee8d1d71 100644
--- a/scripts/gdb/dalvik.gdb
+++ b/scripts/gdb/dalvik.gdb
@@ -49,3 +49,62 @@ document dbt
     frame. If omitted r5 will be used as the default (as the case in the
     interpreter and JIT'ed code).
 end
+
+# ART debugging.  ART uses SIGSEGV signals for internal purposes.  To allow
+# gdb to debug programs using ART we need to treat this signal specially.  We
+# also set a breakpoint in a libart.so function to stop when the program
+# hits an unexpected breakpoint
+set $art_debug_enabled = 0
+define art-on
+    if $art_debug_enabled == 0
+        # deal with SIGSEGV signals
+        handle SIGSEGV noprint nostop pass
+
+        # set a breakpoint and record its number
+        set breakpoint pending on
+        break art_sigsegv_fault
+        set $art_bpnum = $bpnum
+        commands $art_bpnum
+        silent
+        printf "Caught SIGSEGV in user program\n"
+        end
+        set breakpoint pending auto
+
+        printf "ART debugging mode is enabled.\n"
+        set $art_debug_enabled = 1
+    else
+        printf "ART debugging mode is already enabled.\n"
+    end
+end
+
+document art-on
+    Enter ART debugging mode. In ART debugging mode, SIGSEGV signals are ignored
+    by gdb unless they are not handled by ART itself.  A breakpoint is
+    set to stop the program when an unexpected SIGSEGV signal is
+    encountered.
+
+    To switch ART debugging mode off, use "art-off"
+end
+
+define art-off
+    if $art_debug_enabled == 1
+        # restore SIGSEGV to its default
+        handle SIGSEGV print stop pass
+
+        # delete our breakpoint
+        delete $art_bpnum
+
+        set $art_debug_enabled = 0
+        printf "ART debugging mode is disabled.\n"
+    end
+end
+
+document art-off
+    Leave ART debugging mode.  Signal handling is restored to default settings.
+
+    Use the command "art-on" to enable ART debugging mode.
+end
+
+# switch on ART debugging
+art-on
+

From 5661570266848dc7da7131e26f02bdfec392a9a5 Mon Sep 17 00:00:00 2001
From: Christopher Ferris <cferris@google.com>
Date: Fri, 3 Oct 2014 17:31:41 -0700
Subject: [PATCH 2/2] Do not call art-on macro by default.

If you are debugging a native process, SIGSEGV gets ignored by default.
The gdbclient bash function has been modified to only call the art-on
macro when running gdbclient app_processXX.

Also, print a warning in case someone is trying to debug a native
process using app_process.

Bug: 17815162
Change-Id: I0666e6713b0a03ee713be7827c5b671938f2c263
(cherry picked from commit 436b740b705c4316d3d5b73f04cdff9b8b8714e8)
---
 scripts/gdb/dalvik.gdb | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/scripts/gdb/dalvik.gdb b/scripts/gdb/dalvik.gdb
index 6ee8d1d71..6281661ef 100644
--- a/scripts/gdb/dalvik.gdb
+++ b/scripts/gdb/dalvik.gdb
@@ -71,6 +71,9 @@ define art-on
         set breakpoint pending auto
 
         printf "ART debugging mode is enabled.\n"
+        printf "If you are debugging a native only process, you need to\n"
+        printf "re-enable normal SIGSEGV handling using this command:\n"
+        printf "  handle SIGSEGV print stop\n"
         set $art_debug_enabled = 1
     else
         printf "ART debugging mode is already enabled.\n"
@@ -104,7 +107,3 @@ document art-off
 
     Use the command "art-on" to enable ART debugging mode.
 end
-
-# switch on ART debugging
-art-on
-