From f915cc2b2b4f8bbd9d039c66475c76f297043465 Mon Sep 17 00:00:00 2001
From: Ben Clayton <bclayton@google.com>
Date: Fri, 16 Oct 2020 14:26:05 +0100
Subject: [PATCH] Add GN build instructions to README.md

---
 README.md | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 30e85f8b..fa1fe601 100644
--- a/README.md
+++ b/README.md
@@ -88,7 +88,7 @@ The applied stage-specific rules are based on the file extension:
 There is also a non-shader extension
 * `.conf` for a configuration file of limits, see usage statement for example
 
-## Building
+## Building (CMake)
 
 Instead of building manually, you can also download the binaries for your
 platform directly from the [master-tot release][master-tot-release] on GitHub.
@@ -184,6 +184,35 @@ cmake --build . --config Release --target install
 If using MSVC, after running CMake to configure, use the
 Configuration Manager to check the `INSTALL` project.
 
+### Building (GN)
+
+glslang can also be built with the [GN build system](https://gn.googlesource.com/gn/).
+
+#### 1) Install `depot_tools`
+
+Download [depot_tools.zip](https://storage.googleapis.com/chrome-infra/depot_tools.zip),
+extract to a directory, and add this directory to your `PATH`.
+
+#### 2) Synchronize dependencies and generate build files
+
+This only needs to be done once after updating `glslang`.
+
+With the current directory set to your `glslang` checkout, type:
+
+```bash
+gclient sync --gclientfile=standalone.gclient
+gn gen out/Default
+```
+
+#### 3) Build
+
+With the current directory set to your `glslang` checkout, type:
+
+```bash
+cd out/Default
+ninja
+```
+
 ### If you need to change the GLSL grammar
 
 The grammar in `glslang/MachineIndependent/glslang.y` has to be recompiled with