046f987e02
See this doc: go/chromium-coil-change for more info
BUG=1210385
Change-Id: I6cd8548301e360bae8e71384dbd8ef11aa6c985f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2902904
Reviewed-by: My Nguyen <myy@chromium.org>
Commit-Queue: My Nguyen <myy@chromium.org>
Auto-Submit: John Palmer <jopalmer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#885851}
49 lines
1.9 KiB
Markdown
49 lines
1.9 KiB
Markdown
# Graphical Debugging Aid for Chromium Views
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## Introduction
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A simple debugging tool exists to help visualize the views tree during
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debugging. It consists of 4 components:
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1. The function `views::PrintViewGraph()` (in the file
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`ui/views/debug_utils.h`),
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1. a custom debugger command
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- For GDB, see
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[gdbinit](https://chromium.googlesource.com/chromium/src/+/main/docs/gdbinit.md),
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- For LLDB, use `tools/lldb/lldb_viewg.py`
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- For other debuggers, it should be relatively easy to adapt the
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above scripts.
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1. the graphViz package (http://www.graphviz.org/ - downloadable for Linux,
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Windows and Mac), and
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1. an SVG viewer (_e.g._ Chrome).
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## Details
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To use the tool,
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1. Make sure you have 'dot' installed (part of graphViz),
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1. run gdb/lldb on your build and
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1. For GDB see
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[gdbinit](https://chromium.googlesource.com/chromium/src/+/main/docs/gdbinit.md),
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1. For LLDB `command script import tools/lldb/lldb_viewg.py` (this can
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be done automatically in `.lldbinit`),
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1. stop at any breakpoint inside class `View` (or any derived class), and
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1. type `viewg` at the gdb prompt.
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This will cause the current view, and any descendants, to be described in a
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graph which is stored as `~/state.svg` (Windows users may need to modify the
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script slightly to run under CygWin). If `state.svg` is kept open in a browser
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window and refreshed each time `viewg` is run, then it provides a graphical
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representation of the state of the views hierarchy that is always up to date.
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It is easy to modify the gdb script to generate PDF in case viewing with evince
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(or other PDF viewer) is preferred.
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If you don't use gdb or lldb, you may be able to adapt the script to work with
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your favorite debugger. The gdb script invokes
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views::PrintViewGraph(this)
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on the current object, returning `std::string`, whose contents must then be
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saved to a file in order to be processed by dot.
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