如何将Chrome中的V8替换为支持--print-code的调试构建版本

Got it, let's break down exactly how to get Chrome running with a V8 build that supports the --print-code flag—while keeping full DOM support, since standalone d8 can't help with that. Here's a step-by-step guide:

1. Set Up Your Build Environment #

First, you'll need the right tools to compile Chrome and its embedded V8. The exact steps vary by OS:

• Linux: Install dependencies like git, python3, build-essential, libgtk-3-dev, and libnss3-dev using your package manager (e.g., sudo apt-get install ...).
• macOS: Install Xcode (with command-line tools) and Homebrew, then use Homebrew to install python3 and git.
• Windows: Install Visual Studio (2022 recommended, with "Desktop development with C++" workload) and Git.

Next, grab the depot_tools repository (Google's tooling for managing Chrome's codebase):

git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git

Add depot_tools to your system's PATH environment variable so you can run its commands globally.

2. Fetch Chrome's Source Code #

Open a terminal and navigate to the directory where you want to store the Chrome source. Run:

fetch chrome

This will pull down the entire Chrome codebase (including V8) — it's a large download, so be patient. Once done, enter the src directory:

cd src

3. Configure Build Flags for V8 Debugging #

We need to enable V8's disassembler and code-printing features in the Chrome build. Create a build directory (e.g., out/debug_v8) and configure its arguments:

gn args out/debug_v8

A text editor will open. Paste these flags to enable the features you need:

is_debug = true
v8_enable_disassembler = true
v8_enable_debugging = true
v8_print_code = true
# Optional: Use component build for faster incremental builds
is_component_build = true

Save and close the editor. These flags ensure V8 is compiled with support for --print-code and related debugging tools.

4. Compile Chrome #

Start the build with Ninja (the build tool used by Chrome):

ninja -C out/debug_v8 chrome

This will take a while (anywhere from 30 minutes to a few hours, depending on your hardware). Grab a coffee while it runs!

5. Run Your Custom Chrome Build #

Once compilation finishes, launch your custom Chrome build with the --print-code flag:

./out/debug_v8/chrome --js-flags="--print-code"

Now, when Chrome executes JavaScript, you'll see the generated assembly code printed to your terminal. Best of all, this is a full Chrome instance, so DOM and browser features work exactly like the regular version.

Quick Notes #

• If you want a release-optimized build (faster performance, still with --print-code support), set is_debug = false in the GN args, but keep v8_enable_disassembler and v8_print_code set to true.
• The Chrome source code takes up ~50GB of disk space, so make sure you have enough room.
• If you run into build errors, double-check that all dependencies are installed correctly—most issues stem from missing tools.

内容的提问来源于stack exchange，提问作者vimquest