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Gecko:Debugging Tools: Difference between revisions
→Frame Tree Dump: add link to a page with documentation on layout debugger
(bz's notes on frame and reflow logs) |
(→Frame Tree Dump: add link to a page with documentation on layout debugger) |
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== .gdbinit == | |||
[http://web.mit.edu/bzbarsky/www/gdbinit bz's gdbinit] | |||
== GDB pretty printers == | |||
[http://hg.mozilla.org/users/jblandy_mozilla.com/archer-mozilla/ JS-specific printers] | |||
[http://hg.mozilla.org/users/josh_joshmatthews.net/archer-mozilla/ General gecko printers] | |||
== Printing arrays == | |||
define ptarray | |||
if $argc == 0 | |||
help ptarray | |||
else | |||
set $size = $arg0.mHdr->mLength | |||
set $capacity = $arg0.mHdr->mCapacity | |||
set $size_max = $size - 1 | |||
set $elts = $arg0.Elements() | |||
end | |||
if $argc == 1 | |||
set $i = 0 | |||
while $i < $size | |||
printf "elem[%u]: ", $i | |||
p *($elts + $i) | |||
set $i++ | |||
end | |||
end | |||
if $argc == 2 | |||
set $idx = $arg1 | |||
if $idx < 0 || $idx > $size_max | |||
printf "idx1, idx2 are not in acceptable range: [0..%u].\n", $size_max | |||
else | |||
printf "elem[%u]: ", $idx | |||
p *($elts + $idx) | |||
end | |||
end | |||
if $argc == 3 | |||
set $start_idx = $arg1 | |||
set $stop_idx = $arg2 | |||
if $start_idx > $stop_idx | |||
set $tmp_idx = $start_idx | |||
set $start_idx = $stop_idx | |||
set $stop_idx = $tmp_idx | |||
end | |||
if $start_idx < 0 || $stop_idx < 0 || $start_idx > $size_max || $stop_idx > $size_max | |||
printf "idx1, idx2 are not in acceptable range: [0..%u].\n", $size_max | |||
else | |||
set $i = $start_idx | |||
while $i <= $stop_idx | |||
printf "elem[%u]: ", $i | |||
p *($elts + $i) | |||
set $i++ | |||
end | |||
end | |||
end | |||
if $argc > 0 | |||
printf "nsTArray length = %u\n", $size | |||
printf "nsTArray capacity = %u\n", $capacity | |||
printf "Element " | |||
whatis *$elts | |||
end | |||
end | |||
[http://blog.mozilla.com/cjones/2010/04/30/print-nstarrays-in-gdb/ Chris Jones' handy ptarray command] | |||
== Frame Tree Dump == | == Frame Tree Dump == | ||
<bz> for a frame dump, you can use the layout debugger, or... if you're in a debugger and want to examine the tree, you can do | <bz> for a frame dump, you can use the [https://developer.mozilla.org/en-US/docs/Mozilla/Debugging/Layout_Debugger layout debugger], or... if you're in a debugger and want to examine the tree, you can do | ||
def frametree | def frametree | ||
call nsFrame::DumpFrameTree($arg0) | |||
end | end | ||
| Line 13: | Line 77: | ||
<bz> That should work when called on any nsIFrame to dump the tree it belongs to | <bz> That should work when called on any nsIFrame to dump the tree it belongs to | ||
== Printing nsIAtoms == | |||
def pa | |||
set $atom = $arg0 | |||
if (sizeof(*((&*$atom)->mString)) == 2) | |||
pu (&*$atom)->mString | |||
end | |||
end | |||
== Reflow Logs == | == Reflow Logs == | ||
See [[http://www.mozilla.org/newlayout/doc/frame_reflow_debug.html Debugging Frame Reflow]] | See [[http://www.mozilla.org/newlayout/doc/frame_reflow_debug.html Debugging Frame Reflow]] | ||
== Printing strings == | |||
# Define a "ps" command to display subclasses of nsAC?String. Note that | |||
# this assumes strings as of Gecko 1.9 (well, and probably a few | |||
# releases before that as well); going back far enough will get you | |||
# to string classes that this function doesn't work for. | |||
def ps | |||
set $str = $arg0 | |||
if (sizeof(*$str.mData) == 1 && ($str.mFlags & 1) != 0) | |||
print $str.mData | |||
else | |||
pu $str.mData $str.mLength | |||
end | |||
end | |||
# Define a "pu" command to display PRUnichar * strings (100 chars max) | |||
# Also allows an optional argument for how many chars to print as long as | |||
# it's less than 100. | |||
def pu | |||
set $uni = $arg0 | |||
if $argc == 2 | |||
set $limit = $arg1 | |||
if $limit > 100 | |||
set $limit = 100 | |||
end | |||
else | |||
set $limit = 100 | |||
end | |||
# scratch array with space for 100 chars plus null terminator. Make | |||
# sure to not use ' ' as the char so this copy/pastes well. | |||
set $scratch = "____________________________________________________________________________________________________" | |||
set $i = 0 | |||
set $scratch_idx = 0 | |||
while (*$uni && $i++ < $limit) | |||
if (*$uni < 0x80) | |||
set $scratch[$scratch_idx++] = *(char*)$uni++ | |||
else | |||
if ($scratch_idx > 0) | |||
set $scratch[$scratch_idx] = '\0' | |||
print $scratch | |||
set $scratch_idx = 0 | |||
end | |||
print /x *(short*)$uni++ | |||
end | |||
end | |||
if ($scratch_idx > 0) | |||
set $scratch[$scratch_idx] = '\0' | |||
print $scratch | |||
end | |||
end | |||
== Dumping the JS Stack == | |||
def js | |||
call DumpJSStack() | |||
end | |||