From 810a36b18bc2e167da719c18da27d3b87263c7a0 Mon Sep 17 00:00:00 2001
From: kvpanch <223931578+kvpanch@users.noreply.github.com>
Date: Mon, 23 Feb 2026 15:48:07 -0500
Subject: [PATCH] Update EMSDK to 5.0.0 (#479)

Emscripten 4.0.12 introduced breaking change by changing module factory
to always return promise even if `WASM_ASYNC_COMPILATION=0`. To overcome this, build emscripten compiler without MODULARIZE with custom export of `createRevive`.
---
 .cargo/config.toml                    | 4 ++--
 .github/actions/get-emsdk/action.yml  | 2 +-
 .github/workflows/release-llvm.yml    | 4 ++++
 CHANGELOG.md                          | 1 +
 crates/llvm-builder/src/utils.rs      | 2 +-
 js/emscripten/embed/extern-post.js    | 6 ++++++
 js/emscripten/embed/extern-pre.js     | 2 ++
 js/emscripten/examples/node/revive.js | 2 +-
 js/emscripten/examples/web/worker.js  | 2 +-
 9 files changed, 19 insertions(+), 6 deletions(-)
 create mode 100644 js/emscripten/embed/extern-post.js
 create mode 100644 js/emscripten/embed/extern-pre.js

diff --git a/.cargo/config.toml b/.cargo/config.toml
index 3bf5f97..fb2c62d 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -5,9 +5,9 @@ rustflags = [
     "-Clink-arg=-sEXIT_RUNTIME=1",
     "-Clink-arg=-sALLOW_MEMORY_GROWTH=1",
     "-Clink-arg=-sEXPORTED_RUNTIME_METHODS=FS,callMain,stringToNewUTF8",
-    "-Clink-arg=-sMODULARIZE=1",
-    "-Clink-arg=-sEXPORT_NAME=createRevive",
     "-Clink-arg=-sWASM_ASYNC_COMPILATION=0",
+    "-Clink-arg=--extern-pre-js=js/emscripten/embed/extern-pre.js",
+    "-Clink-arg=--extern-post-js=js/emscripten/embed/extern-post.js",
     "-Clink-arg=-sDYNAMIC_EXECUTION=0",
     "-Clink-arg=-sALLOW_TABLE_GROWTH=1",
     "-Clink-arg=--js-library=js/emscripten/embed/soljson_interface.js",
diff --git a/.github/actions/get-emsdk/action.yml b/.github/actions/get-emsdk/action.yml
index dcb8e3d..cc7b710 100644
--- a/.github/actions/get-emsdk/action.yml
+++ b/.github/actions/get-emsdk/action.yml
@@ -3,7 +3,7 @@ inputs:
   version:
     description: ""
     required: false
-    default: "4.0.9"
+    default: "5.0.0"
 
 
 runs:
diff --git a/.github/workflows/release-llvm.yml b/.github/workflows/release-llvm.yml
index 7ae680b..3a5b9d0 100644
--- a/.github/workflows/release-llvm.yml
+++ b/.github/workflows/release-llvm.yml
@@ -79,6 +79,10 @@ jobs:
           rustflags: ""
           cache-key: ${{ matrix.target }}
 
+      - name: Enable long paths (Windows)
+        if: runner.os == 'Windows'
+        run: git config --system core.longpaths true
+
       - name: Install Dependencies
         if: ${{ matrix.host == 'linux' }}
         run: |
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 622b50e..6776f51 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ This is a development pre-release.
 - Updated `musl` to `1.2.5`
 - Updated `inkwell` to `0.8.0`
 - Updated `polkavm-*` to `0.31.0`
+- Updated `EMSDK` to `5.0.0`
 
 ## v1.0.0
 
diff --git a/crates/llvm-builder/src/utils.rs b/crates/llvm-builder/src/utils.rs
index fbd2b33..f9b9e5a 100644
--- a/crates/llvm-builder/src/utils.rs
+++ b/crates/llvm-builder/src/utils.rs
@@ -38,7 +38,7 @@ pub const MUSL_SNAPSHOTS_URL: &str = "https://git.musl-libc.org/cgit/musl/snapsh
 pub const EMSDK_SOURCE_URL: &str = "https://github.com/emscripten-core/emsdk.git";
 
 /// The emscripten SDK version.
-pub const EMSDK_VERSION: &str = "4.0.9";
+pub const EMSDK_VERSION: &str = "5.0.0";
 
 /// The subprocess runner.
 ///
diff --git a/js/emscripten/embed/extern-post.js b/js/emscripten/embed/extern-post.js
new file mode 100644
index 0000000..7b48f34
--- /dev/null
+++ b/js/emscripten/embed/extern-post.js
@@ -0,0 +1,6 @@
+return Module;
+}
+if (typeof module === "object" && typeof module.exports === "object") {
+  module.exports = createRevive;
+} else if (typeof define === "function" && define["amd"])
+  define([], () => createRevive);
diff --git a/js/emscripten/embed/extern-pre.js b/js/emscripten/embed/extern-pre.js
new file mode 100644
index 0000000..e46e2b6
--- /dev/null
+++ b/js/emscripten/embed/extern-pre.js
@@ -0,0 +1,2 @@
+function createRevive(moduleArg) {
+var Module = moduleArg || {};
diff --git a/js/emscripten/examples/node/revive.js b/js/emscripten/examples/node/revive.js
index 8fe1173..83f96ea 100644
--- a/js/emscripten/examples/node/revive.js
+++ b/js/emscripten/examples/node/revive.js
@@ -1,7 +1,7 @@
 const soljson = require("solc/soljson");
 const createRevive = require("./resolc.js");
 
-async function compile(standardJsonInput) {
+function compile(standardJsonInput) {
   if (!standardJsonInput) {
     throw new Error("Input JSON for the Solidity compiler is required.");
   }
diff --git a/js/emscripten/examples/web/worker.js b/js/emscripten/examples/web/worker.js
index aa39b58..9fe888e 100644
--- a/js/emscripten/examples/web/worker.js
+++ b/js/emscripten/examples/web/worker.js
@@ -1,7 +1,7 @@
 importScripts("./resolc_web.js");
 
 // Handle messages from the main thread
-onmessage = async function (e) {
+onmessage = function (e) {
   const m = createRevive();
 
   // Set input data for stdin