From e509e34100e9ed63cf44684538f64493d7cbcabb Mon Sep 17 00:00:00 2001
From: Chinmay Garde <chinmaygarde@google.com>
Date: Mon, 1 Apr 2024 13:39:04 -0700
Subject: [PATCH 1/2] Allow creating slimpeller engine variants.

Fixes https://github.com/flutter/flutter/issues/144432
---
 common/config.gni |  8 ++++++++
 tools/gn          | 11 +++++++++++
 2 files changed, 19 insertions(+)

diff --git a/common/config.gni b/common/config.gni
index ef1b0288bb844..1e9e771ca3806 100644
--- a/common/config.gni
+++ b/common/config.gni
@@ -28,6 +28,10 @@ declare_args() {
   #TODO(cyanglaz): Remove above comment about test flag when the entire iOS embedder supports app extension
   #https://github.com/flutter/flutter/issues/124289
   darwin_extension_safe = false
+
+  # Whether binary size optimizations with the assumption that Impeller is the
+  # only supported rendering engine are enabled.
+  slimpeller = false
 }
 
 # feature_defines_list ---------------------------------------------------------
@@ -62,6 +66,10 @@ if (flutter_runtime_mode == "debug") {
   feature_defines_list += [ "FLUTTER_RUNTIME_MODE=0" ]
 }
 
+if (slimpeller) {
+  feature_defines_list += [ "SLIMPELLER=1" ]
+}
+
 if (is_ios || is_mac) {
   flutter_cflags_objc = [
     "-Werror=overriding-method-mismatch",
diff --git a/tools/gn b/tools/gn
index 0be76e5477334..f5d73dea9b662 100755
--- a/tools/gn
+++ b/tools/gn
@@ -68,6 +68,9 @@ def get_out_dir(args):
   if args.darwin_extension_safe:
     target_dir.append('extension_safe')
 
+  if args.slimpeller:
+    target_dir.append('slimpeller')
+
   if args.target_dir != '':
     target_dir = [args.target_dir]
 
@@ -1260,6 +1263,14 @@ def parse_args(args):
       help='Do not run GN. Instead configure the Impeller cmake example build.',
   )
 
+  parser.add_argument(
+      '--slimpeller',
+      default=False,
+      action='store_true',
+      help='Enable optimizations that attempt to reduce binary size of the ' +
+      'Flutter engine by assuming only the Impeller rendering engine is supported.'
+  )
+
   # Sanitizers.
   parser.add_argument('--asan', default=False, action='store_true')
   parser.add_argument('--lsan', default=False, action='store_true')

From 7d6b10a22064978c40501269571433c71c431ac6 Mon Sep 17 00:00:00 2001
From: Chinmay Garde <chinmaygarde@google.com>
Date: Tue, 2 Apr 2024 11:42:09 -0700
Subject: [PATCH 2/2] Add links to the project.

---
 common/config.gni | 3 +++
 tools/gn          | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/common/config.gni b/common/config.gni
index 1e9e771ca3806..6ec3e4c03e795 100644
--- a/common/config.gni
+++ b/common/config.gni
@@ -31,6 +31,9 @@ declare_args() {
 
   # Whether binary size optimizations with the assumption that Impeller is the
   # only supported rendering engine are enabled.
+  #
+  # See [go/slimpeller-dashboard](https://github.com/orgs/flutter/projects/21)
+  # for details.
   slimpeller = false
 }
 
diff --git a/tools/gn b/tools/gn
index f5d73dea9b662..88943c90cb892 100755
--- a/tools/gn
+++ b/tools/gn
@@ -1268,7 +1268,8 @@ def parse_args(args):
       default=False,
       action='store_true',
       help='Enable optimizations that attempt to reduce binary size of the ' +
-      'Flutter engine by assuming only the Impeller rendering engine is supported.'
+      'Flutter engine by assuming only the Impeller rendering engine is supported.' +
+      'See [go/slimpeller-dashboard](https://github.com/orgs/flutter/projects/21) for details.'
   )
 
   # Sanitizers.