From a8f268f2355a3ead9a4ced6c934d271c16b8d6b2 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Wed, 8 Dec 2021 12:19:48 +0100
Subject: [PATCH] Compile the Wasm node with -Os (#1729)

---
 .github/workflows/ci.yml            |  4 ++--
 Cargo.toml                          |  5 +++++
 bin/wasm-node/javascript/prepare.js | 12 ++++++------
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7b65a311c0..8cfff539a6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -72,10 +72,10 @@ jobs:
     - run: cargo install twiggy  # TODO: somehow cache this in order to not compile twiggy every single time
     - run: git checkout ${{ github.event.pull_request.base.sha }}
     - run: cd bin/wasm-node/javascript && npm ci && npm run-script build
-    - run: cp ./target/wasm32-wasi/release/smoldot_light_wasm.wasm ./.ci-parent-build.wasm  # TODO: update path after https://github.com/paritytech/smoldot/pull/1729
+    - run: cp ./target/wasm32-wasi/release/smoldot_light_wasm.wasm ./.ci-parent-build.wasm  # TODO: update the path, plus maybe get the path from the `npm build` output or something?
     - run: git checkout ${{ github.event.pull_request.head.sha }}
     - run: cd bin/wasm-node/javascript && npm ci && npm run-script build
-    - run: twiggy diff ./.ci-parent-build.wasm ./target/wasm32-wasi/release/smoldot_light_wasm.wasm > ./twiggy-diff  # TODO: update path after https://github.com/paritytech/smoldot/pull/1729
+    - run: twiggy diff ./.ci-parent-build.wasm ./target/wasm32-wasi/min-size-release/smoldot_light_wasm.wasm > ./twiggy-diff  # TODO: maybe get the path from the `npm build` output or something?
     # Now that we've generated the diff in a `./twiggy-diff` file, the next step is to upload
     # the PR number and diff content as an artifact that will then be picked up by a
     # `workflow_run` action that does the actual commenting.
diff --git a/Cargo.toml b/Cargo.toml
index 5faac1d990..b22ad3cece 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -126,6 +126,11 @@ panic = "abort"
 lto = true
 #strip = "symbols"      # TODO: uncomment once stable
 
+[profile.min-size-release]
+inherits = "release"
+lto = true
+opt-level = "z"
+
 [[bench]]
 name = "header"
 harness = false
diff --git a/bin/wasm-node/javascript/prepare.js b/bin/wasm-node/javascript/prepare.js
index c37ad8c4ef..a743661901 100755
--- a/bin/wasm-node/javascript/prepare.js
+++ b/bin/wasm-node/javascript/prepare.js
@@ -27,9 +27,9 @@ if (process.argv.slice(2).indexOf("--debug") !== -1) {
 if (process.argv.slice(2).indexOf("--release") !== -1) {
     if (build_profile)
         throw new Error("Can't pass both --debug and --release");
-    build_profile = 'release';
+    build_profile = 'min-size-release';
 }
-if (build_profile != 'debug' && build_profile != 'release')
+if (build_profile != 'debug' && build_profile != 'min-size-release')
     throw new Error("Either --debug or --release must be passed");
 
 // The Rust version to use.
@@ -61,8 +61,8 @@ child_process.execSync(
 // The important step in this script is running `cargo build --target wasm32-wasi` on the Rust
 // code. This generates a `wasm` file in `target/wasm32-wasi`.
 child_process.execSync(
-    "cargo +" + rust_version + " build --package smoldot-light-wasm --target wasm32-wasi --no-default-features"
-    + (build_profile == 'debug' ? '' : ' --' + build_profile),
+    "cargo +" + rust_version + " build --package smoldot-light-wasm --target wasm32-wasi --no-default-features " +
+        (build_profile == 'debug' ? '' : ("--profile " + build_profile)),
     { 'stdio': 'inherit' }
 );
 
@@ -71,9 +71,9 @@ child_process.execSync(
 // use the `.wasm` generated by the Rust compiler.
 let fallback_copy = false;
 try {
-    if (build_profile == 'release') {
+    if (build_profile == 'min-size-release') {
         child_process.execSync(
-            "wasm-opt -o src/autogen/tmp.wasm -Os --strip-debug --vacuum --dce "
+            "wasm-opt -o src/autogen/tmp.wasm -Oz --strip-debug --vacuum --dce "
             + "../../../target/wasm32-wasi/" + build_profile + "/smoldot_light_wasm.wasm",
             { 'stdio': 'inherit' }
         );