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Using Sublime Text as your IDE

The below instructions are outdated.

New instructions:

https://chromium.googlesource.com/chromium/src/+/HEAD/docs/sublime_ide.md

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What is Sublime Text?

It's a fast, powerful and easily extensible code editor. Check out some of the demos on the site for a quick visual demonstration.

Some of its benefits include:

Installing Sublime Text 2

Download and install from here: http://www.sublimetext.com/

Help and general documentation is available here: http://www.sublimetext.com/docs/2/

Assuming you have access to the right repositories, you can also install Sublime via apt-get on Linux.

Preferences

Sublime configuration is done via JSON files. So the UI for configuring the text editor is simply a text editor. Same goes for project files, key bindings etc.

To modify the default preferences, go to the Preferences menu and select Settings-Default. Note that if you would rather like to make these settings user specific, select Settings - User as this applies there as well. The difference is that the default settings file already contains many settings that you might want to modify.

Here are some settings that you might want to change (look these variables up in the settings file and modify their value, you should not have to add them):

    "rulers": [80],
    "tab_size": 2,
    "trim_trailing_white_space_on_save": true,
    "ensure_newline_at_eof_on_save": true,
    "translate_tabs_to_spaces" : true

The settings take effect as soon as you save the file.

If you've got a big monitor and are used to viewing more than one source file at a time, you can use the View->Layout feature to split the view up into columns and/or rows and look at multiple files at the same time. There's also the Shift+F11, distraction free view that allows you to see nothing but code! ?8-D Sublime also supports dragging tabs out into new windows as Chrome supports, so that might be useful as well.

One thing to be aware of when editing these JSON files is that Sublime's JSON parser is slightly stricter than what you might be used to from editing e.g. GYP files. In particular Sublime does not like it if you end a collection with a comma. This is legal: {"foo", "bar"} but not this: {"foo", "bar", }. You have been warned.

Project files

Like configuration files, project files are just user editable JSON files.

Here's a very simple project file that was created for WebRTC and should be saved in the parent folder of the trunk folder (name it webrtc.sublime-project). It's as bare bones as it gets, so when you open this project file, you'll probably see all sorts of files that you aren't interested in.

{
	"folders":
	[
		{
			"path": "trunk"
		}
	]
}

Here is a slightly more advanced example that has exclusions to reduce clutter. This one was made for Chrome on a Windows machine and has some Visual Studio specific excludes. Save this file in the same directory as your .gclient file and use the .sublime-project extension (e.g. chrome.sublime-project) and then open it up in Sublime.

{
	"folders":
	[
		{
			"path": "src",
			"name": "src",
			"file_exclude_patterns": [
				"*.vcproj",
				"*.vcxproj",
				"*.sln",
				"*.gitignore",
				"*.gitmodules",
				"*.vcxproj.*"
			],
			"folder_exclude_patterns": [
			  "build",
			  "out",
			  "third_party",
			  ".git",
			  "Debug",
			  "Release"
			]
		}
	]
}

Here are some basic ways to get you started browsing the source code.

Enable source code indexing

For a fast way to look up symbols, we recommend installing the CTags plugin. we also recommend installing Sublime's Package Control package manager, so let's start with that.

Once installed, you'll get an entry in the context menu when you right click the top level folder(s) in your project that allow you to build the Ctags database. If you're working in a Chrome project however, do not do that at this point, since it will index much more than you actually want. Instead, do one of:

  1. Create a batch file (e.g. ctags_builder.bat) that you can run either manually or automatically after you do a gclient sync:

    ctags --languages=C++ --exclude=third_party --exclude=.git --exclude=build --exclude=out -R -f .tmp_tags & ctags --languages=C++ -a -R -f .tmp_tags third_party\platformsdk_win8 & ctags --languages=C++ -a -R -f .tmp_tags third_party\WebKit & move /Y .tmp_tags .tags

    This takes a couple of minutes to run, but you can work while it is indexing.

  2. Edit the CTags.sublime-settings file for the ctags plugin so that it runs ctags with the above parameters. Note: the above is a batch file - don't simply copy all of it verbatim and paste it into the CTags settings file :-)

Once installed, you can quickly look up symbols with Ctrl+t, Ctrl+t etc. More information here: https://github.com/SublimeText/CTags

One more hint - Edit your .gitignore file (under %USERPROFILE% or ~/) so that git ignores the .tags file. You don't want to commit it. :)

If you don't have a .gitignore in your profile directory, you can tell git about it with this command:

Windows: git config --global core.excludesfile %USERPROFILE%\.gitignore
Mac, Linux: git config --global core.excludesfile ~/.gitignore

Building with ninja

Assuming that you've got ninja properly configured and that you already have a project file as described above, here's how to build Chrome using ninja from within Sublime. For any other target, just replace the target name.

Go to Tools->Build System->New build system and save this as a new build system:

{
	"cmd": ["ninja", "-C", "out\\Debug", "chrome.exe"],
	"working_dir": "${project_path}\\src",
	"file_regex": "^[.\\\\/]*([a-z]?:?[\\w.\\\\/]+)[(:]([0-9]+)[):,]([0-9]+)?[:)]?(.*)$"
}

file_regex explained for easier tweaking in future:


Aims to capture the following error formats while respecting [Sublime's perl-like group matching](http://sublimetext.info/docs/en/reference/build_systems.html):
 1. d:\src\chrome\src\base\threading\sequenced_worker_pool.cc(670): error C2653: 'Foo': is not a class or namespace name
 2. ../../base/threading/sequenced_worker_pool.cc:670:26: error: use of undeclared identifier 'Foo'
 3. ../../base/process/memory_win.cc(18,26):  error: use of undeclared identifier 'Foo'
 4. ../..\src/heap/item-parallel-job.h(145,31):  error: expected ';' in 'for' statement specifier
"file_regex": "^[.\\\\/]*([a-z]?:?[\\w.\\-\\\\/]+)[(:]([0-9]+)[):,]([0-9]+)?[:)]?(.*)$"
                (   0   ) (   1  )(      2      ) (3 ) (  4 ) ( 5 ) (  6   )( 7 )(8 )
(0) Cut relative paths (which typically are relative to the out dir and targeting src/ which is already the "working_dir")
(1) Match a drive letter if any
(2) Match the rest of the file
(1)+(2) Capture the "filename group"
(3) File name is followed by open bracket or colon before line number
(4) Capture "line number group"
(5) Line # is either followed by close bracket (no column group) or comma/colon
(6) Capture "column filename group" if any.
(7) If (6) is non-empty there will be a closed bracket or another colon (but can't put it inside brackets as the "column filename group" only wants digits).
(8) Everything else until EOL is the error message.

On Linux and Mac, fix the targets up appropriately, fwd slash instead of backslash, no .exe, etc

Linux example:

{
 // Pass -j1024 if (and only if!) building with reclient/RBE.
 "cmd": ["ninja", "-C", "out/Debug", "blink", "-j1024"],
 "working_dir": "${project_path}/src",
 // Ninja/GN build errors are build-dir relative, however file_regexp
 // is expected to produce project-relative paths, ignore the leading
 // ../../ to make that happen.
 // ../../(file_path):(line_number):(column):(error_message)
 "file_regex": "^../../([^:\n]*):([0-9]+):?([0-9]+)?:? (.*)$"
}

or to avoid making ninja in the path or environment variables:

{
 "cmd": ["/usr/local/google/home/MYUSERNAME/git/depot_tools/ninja", "-j", "150", "-C", ".", "chrome", "content_shell", "blink_tests"],
 "working_dir": "${project_path}/src/out/Release",
 "file_regex": "([^:\n]*):([0-9]+):?([0-9]+)?:? (.*)$",
 "variants":
   [
    {
      "cmd": ["/usr/local/google/home/MYUSERNAME/git/depot_tools/ninja", "-j", "150", "-C", ".", "chrome", "content_shell", "blink_tests"],
      "name": "chrome_debug_blink",
      "working_dir": "${project_path}/src/out/Debug",
      "file_regex": "([^:\n]*):([0-9]+):?([0-9]+)?:? (.*)$"
    }
  ]
}

Further build system documentation or older documentation (as of Nov 2014 older is more complete).

This will make hitting Ctrl-B build chrome.exe (really quickly, thanks to ninja), F4 will navigate to the next build error, etc. If you're using RBE, you can play with something like: "cmd": ["ninja", "-j", "200", "-C", "out\\Debug", "chrome.exe"],.

You can also add build variants so that you can also have quick access to building other targets like unit_tests or browser_tests. You build description file could look like this:

{  "cmd": ["ninja", "-j200", "-C", "out\\Debug", "chrome.exe"],  "working_dir": "${project_path}\\src",  "file_regex": "^[.\\\\/]*([a-z]?:?[\\w.\\\\/]+)[(:]([0-9]+)[):]([0-9]+)?:?(.*)$",  "variants":  [    {      "cmd": ["ninja", "-j200", "-C", "out\\Debug", "unit_tests.exe"],      "name": "unit_tests"    },    {      "cmd": ["ninja", "-j200", "-C", "out\\Debug", "browser_tests.exe"],      "name": "browser_tests"    }  ]}

This way, you have separate key binding to start the unit or browser tests target build as follows:

  { "keys": ["ctrl+shift+u"], "command": "build", "args": {"variant": "unit_tests"} },  { "keys": ["ctrl+shift+b"], "command": "build", "args": {"variant": "browser_tests"} }

And keep using "ctrl+b" for a regular, "chrome.exe" build. Enjoy!

Example plugin

Sublime has a Python console window and supports Python plugins. So if there's something you feel is missing, you can simply add it.

Here's an example plugin (Tools->New Plugin) that runs cpplint (assuming depot_tools is in the path) for the current file and prints the output to Sublime's console window (Ctrl+`):

import sublime, sublime_plugin
import subprocess
class RunLintCommand(sublime_plugin.TextCommand):
  def run(self, edit):
      command = ["cpplint.bat", self.view.file_name()]
      process = subprocess.Popen(command, shell=True,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE)
      print process.communicate()[1]

Or, in Sublime Text 3:

from future import print_function

import sublime, sublime_plugin

import subprocess

class RunLintCommand(sublime_plugin.TextCommand):

def run(self, edit):

print("AMI: %s" % self.view.file_name())

command = ["/home/fischman/src/depot_tools/cpplint.py", self.view.file_name()]

process = subprocess.Popen(command, shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

output, error = process.communicate()

if error:

print(error)

Save this file as run_lint.py (Sublime will suggest the right location when you save the plugin - Packages\User).

You can run the command via the console like so:

view.run_command('run_lint')

Note that here's an interesting thing in how Sublime works. CamelCaps are converted to lower_case_with_undescore format. Note also that although the documentation currently has information about "runCommand" member method for the view object, this too is now subject to that convention.

Taking this a step further, you can create a keybinding for your new plugin. Here's an example for how you could add a binding to your User key bindings (Preferences->Key Bindings - User):

[
    {
        "keys": ["ctrl+shift+l"], "command": "run_lint"
    }
]

Now, when you hit Ctrl+Shift+L, cpplint will be run for the currently active view. Here's an example output from the console window:

D:\src\cgit\src\content\browser\browsing_instance.cc:69:  Add #include <string> for string  [build/include_what_you_use] [4]
Done processing D:\src\cgit\src\content\browser\browsing_instance.cc
Total errors found: 1

As a side note, if you run into problems with the documentation as I did above, it's useful to just use Python's ability to dump all properties of an object with the dir() function:

>>> dir(view)
['__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__getattribute__', '__hash__', '__init__', '__len__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'add_regions', 'begin_edit', 'buffer_id', 'classify', 'command_history', 'em_width', 'encoding', 'end_edit', 'erase', 'erase_regions', 'erase_status', 'extract_completions', 'extract_scope', ... <snip>

Compile current file using Ninja

As a more complex plug in example, look at the attached python file: compile_current_file.py. This plugin will compile the current file with Ninja, so will start by making sure that all this file's project depends on has been built before, and then build only that file.

First, it confirms that the file is indeed part of the current project (by making sure it's under the <project_root> folder, which is taken from the self.view.window().folders() array, the first one seems to always be the project folder when one is loaded). Then it looks for the file in all the .ninja build files under the <project_root>\out\<target_build>, where <target_build> must be specified as an argument to the compile_current_file command. Using the proper target for this file compilation, it starts Ninja from a background thread and send the results to the output.exec panel (the same one used by the build system of Sublime Text 2). So you can use key bindings like these two, to build the current file in either Debug or Release mode:

  { "keys": ["ctrl+f7"], "command": "compile_current_file", "args": {"target_build": "Debug"} },
  { "keys": ["ctrl+shift+f7"], "command": "compile_current_file", "args": {"target_build": "Release"} },

If you are having trouble with this plugin, you can set the python logging level to DEBUG in the console and see some debug output.

Format selection (or area around cursor) using clang-format

Copy buildtools/clang_format/scripts/clang-format-sublime.py to ~/.config/sublime-text-3/Packages/User/ (or -2 if still on ST2) and add something like this to Preferences->Key Bindings - User:

"keys": ["ctrl+shift+c"], "command": "clang_format",

Miscellaneous tips

Other useful packages

Assuming you've installed Package Control already (https://packagecontrol.io/installation) you can easily install more packages via:

  1. Open Command Palette (Ctrl-Shift-P)
  2. Type "Package Control: Install Package" (note: given ST's string match is amazing you can just type something like "instp" and it will find it :-)).

A few recommended packages: