From f008fb265429a7e3fb65ed04bc310ac0f464bee2 Mon Sep 17 00:00:00 2001
From: Daniel Jacobs <danielhunterjacobs@gmail.com>
Date: Fri, 8 Nov 2024 15:33:00 -0500
Subject: [PATCH 1/2] web: Allow building an MVP vanilla WASM module

---
 web/README.md                         |  1 +
 web/packages/core/tools/build_wasm.ts | 19 ++++++++++++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/web/README.md b/web/README.md
index 9393fce7fc9a..51be380d425b 100644
--- a/web/README.md
+++ b/web/README.md
@@ -106,6 +106,7 @@ In this project, you may run the following commands to build all packages:
     -   There is `npm run build:dual-wasm` as well, to build a second WebAssembly module that makes use of some WebAssembly extensions,
         potentially resulting in better performance in browsers that support them, at the expense of longer build time.
     -   `npm run build:repro` enables reproducible builds. Note that this also requires a `version_seal.json`, which is not provided in the normal Git repository - only specially-marked reproducible source archives. Running this without a version seal will generate one based on the current state of your environment.
+    -   With either of the prior two commands, you can set the environment variable `BUILD_WASM_MVP=1`. This will build the vanilla WASM module using nightly Rust and disable all WebAssembly features that Rust enables by default. You will first need to run the command `rustup target add wasm32-unknown-unknown --toolchain nightly` so nightly Rust can also output WebAssembly.
 
 From here, you may follow the instructions to [use Ruffle on your website](packages/selfhosted/README.md),
 run a demo locally with `npm run demo`, or [install the extension in your browser](https://github.com/ruffle-rs/ruffle/wiki/Using-Ruffle#browser-extension).
diff --git a/web/packages/core/tools/build_wasm.ts b/web/packages/core/tools/build_wasm.ts
index 61c93ea52c3a..bb70c03d0e9b 100644
--- a/web/packages/core/tools/build_wasm.ts
+++ b/web/packages/core/tools/build_wasm.ts
@@ -42,12 +42,25 @@ function cargoBuild({
     profile,
     features,
     rustFlags,
+    extensions,
 }: {
     profile?: string;
     features?: string[];
     rustFlags?: string[];
+    extensions?: boolean;
 }) {
-    let args = ["build", "--locked", "--target", "wasm32-unknown-unknown"];
+    let args =
+        !extensions && process.env["BUILD_WASM_MVP"]
+            ? [
+                  "+nightly",
+                  "build",
+                  "--locked",
+                  "-Z",
+                  "build-std=std,panic_abort",
+                  "--target",
+                  "wasm32-unknown-unknown",
+              ]
+            : ["build", "--locked", "--target", "wasm32-unknown-unknown"];
     if (profile) {
         args.push("--profile", profile);
     }
@@ -99,9 +112,13 @@ function buildWasm(
     let originalWasmPath;
     if (wasmSource === "cargo" || wasmSource === "cargo_and_store") {
         console.log(`Building ${flavor} with cargo...`);
+        if (process.env["BUILD_WASM_MVP"]) {
+            rustFlags.push("-C", "target-cpu=mvp");
+        }
         cargoBuild({
             profile,
             rustFlags,
+            extensions,
         });
         originalWasmPath = `../../../target/wasm32-unknown-unknown/${profile}/ruffle_web.wasm`;
         if (wasmSource === "cargo_and_store") {

From 694c3b13d84c639c300518b20557dce88ac037b0 Mon Sep 17 00:00:00 2001
From: Daniel Jacobs <danielhunterjacobs@gmail.com>
Date: Mon, 2 Dec 2024 12:07:50 -0500
Subject: [PATCH 2/2] web: Add envvar to pin the nightly Rust version when
 building dual-wasm

---
 web/packages/core/tools/build_wasm.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/web/packages/core/tools/build_wasm.ts b/web/packages/core/tools/build_wasm.ts
index bb70c03d0e9b..4ffcef2e7199 100644
--- a/web/packages/core/tools/build_wasm.ts
+++ b/web/packages/core/tools/build_wasm.ts
@@ -52,7 +52,9 @@ function cargoBuild({
     let args =
         !extensions && process.env["BUILD_WASM_MVP"]
             ? [
-                  "+nightly",
+                  process.env["NIGHTLY_VERSION"]
+                      ? `+nightly-${process.env["NIGHTLY_VERSION"]}`
+                      : "+nightly",
                   "build",
                   "--locked",
                   "-Z",