solve review comments

doc/contributing/gn-build.md

@@ -4,12 +4,18 @@ Similar to GYP, GN is a build system designed for building Chromium. The
 official builds of Node.js are built with GYP, but GN build files are also
 provided as an unofficial alternative build system.
 
+The GN build files only support a subset of the Node.js build configurations.
+It's not required for all pull requests to Node.js to support GN builds, and
+Node.js's own CI does not currently test GN builds, though Node.js welcomes pull
+requests that improve GN support or fix breakages introduced by other pull
+requests.
+
 Currently the GN build is used by:
 
 1. Electron for building Node.js together with Chromium.
 2. V8 for testing the integration of Node.js in CI.
 
-## Files of GN
+## Files for GN support
 
 Node.js contains following GN build files:
 
@@ -24,14 +30,15 @@ Unlike GYP, the GN tool does not include any built-in rules for compiling a
 project, which means projects building with GN must provide their own build
 configurations for things like how to invoke a C++ compiler. Chromium related
 projects like V8 and skia choose to reuse Chromium's build configurations, and
-we are reusing V8's Node.js integration testing repository
-([node-ci](https://chromium.googlesource.com/v8/node-ci/)) for building Node.js.
+V8's Node.js integration testing repository
+([node-ci](https://chromium.googlesource.com/v8/node-ci/)) can be reused for
+building Node.js.
 
 ### 1. Install `depot_tools`
 
 The `depot_tools` is a set of tools used by Chromium related projects for
-checking out code and managing dependencies, and since we are reusing the infra
-of V8, we have to install and add it to `PATH`:
+checking out code and managing dependencies, and since this guide is reusing the
+infra of V8, it needs to be installed and added to `PATH`:
 
 ```bash
 git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
@@ -41,7 +48,7 @@ export PATH=/path/to/depot_tools:$PATH
 You can also follow the [official tutorial of
 `depot_tools`](https://commondatastorage.googleapis.com/chrome-infra-docs/flat/depot_tools/docs/html/depot_tools_tutorial.html).
 
-### 2. Check out code
+### 2. Check out code of Node.js
 
 To check out the latest main branch of Node.js for building, use the `fetch`
 tool from `depot_tools`:
@@ -77,36 +84,42 @@ The `node_gn` is a workspace directory, which only contains configurations and
 caches of the `gclient` tool from `depot_tools`, and the repository is checked
 out at `node_gn/node`.
 
-The `node_gn/node` directory is not the repository of Node.js, it is actually
-node-ci, the repository used by V8 for testing integration with Node.js. The
-source code of Node.js is checked out at `node_gn/node/node`.
+The `node_gn/node` directory is not a checkout of Node.js, it is actually
+[node-ci](https://chromium.googlesource.com/v8/node-ci/), the repository used by
+V8 for testing integration with Node.js. The source code of Node.js is checked
+out at `node_gn/node/node`.
 
 ### 3. Build
 
 GN only supports [`ninja`](https://ninja-build.org) for building, so to build
-Node.js with GN we have to generate `ninja` build files first and then call
-`ninja` to do the building.
+Node.js with GN, `ninja` build files should be generated first, and then
+`ninja` can be invoked to do the building.
 
 The `node-ci` repository provides a script for calling GN:
 
 ```bash
+cd node  # Enter `node_gn/node` which contains a node-ci checkout
 ./tools/gn-gen.py out/Release
 ```
 
-which writes `ninja` build files into the `out/Release` directory.
+which writes `ninja` build files into the `out/Release` directory under
+`node_gn/node`.
 
 And then you can execute `ninja`:
 
 ```bash
 ninja -C out/Release node
 ```
 
+After the build is completed, the compiled Node.js executable can be found in
+`out/Release/node`.
+
 ## Status of the GN build
 
 Currently the GN build of Node.js is not fully functioning. It builds for macOS
-and Linux, but we are still fixing a few issues to make the Windows build work.
-And not all tests are passing using the GN build.
+and Linux, while the Windows build is still a work in progress. And some tests
+are still failing with the GN build.
 
-There are also efforts on [making GN build work without using
-`depot_tools`](https://github.com/photoionization/node_with_gn), which uses a
-[forked version of GN](https://github.com/yue/build-gn).
+There are also efforts on making GN build work without using `depot_tools`,
+which is tracked in the issue
+[#51689](https://github.com/nodejs/node/issues/51689).