From 1e3cc7565bf98a6d6d12e7a55fec7723c85d0950 Mon Sep 17 00:00:00 2001
From: daxpedda <daxpedda@gmail.com>
Date: Thu, 19 Dec 2024 10:21:16 +0100
Subject: [PATCH] Apply transformations even if the shim is empty

---
 CHANGELOG.md                                  |  3 +
 .../cli/tests/reference/intrinsic-only.d.ts   |  3 +
 crates/cli/tests/reference/intrinsic-only.js  | 57 +++++++++++++++++++
 crates/cli/tests/reference/intrinsic-only.rs  |  6 ++
 crates/cli/tests/reference/intrinsic-only.wat | 17 ++++++
 crates/externref-xform/src/lib.rs             |  6 --
 6 files changed, 86 insertions(+), 6 deletions(-)
 create mode 100644 crates/cli/tests/reference/intrinsic-only.d.ts
 create mode 100644 crates/cli/tests/reference/intrinsic-only.js
 create mode 100644 crates/cli/tests/reference/intrinsic-only.rs
 create mode 100644 crates/cli/tests/reference/intrinsic-only.wat

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 72bc905f84f..f00eaaa3cb8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -64,6 +64,9 @@
 * Error if URL in `<WEBDRIVER>_REMOTE` can't be parsed.
   [#4362](https://github.com/rustwasm/wasm-bindgen/pull/4362)
 
+* Internal functions are now removed instead of invalidly imported if they are unused.
+  [#4366](https://github.com/rustwasm/wasm-bindgen/pull/4366)
+
 --------------------------------------------------------------------------------
 
 ## [0.2.99](https://github.com/rustwasm/wasm-bindgen/compare/0.2.98...0.2.99)
diff --git a/crates/cli/tests/reference/intrinsic-only.d.ts b/crates/cli/tests/reference/intrinsic-only.d.ts
new file mode 100644
index 00000000000..bb95c9509da
--- /dev/null
+++ b/crates/cli/tests/reference/intrinsic-only.d.ts
@@ -0,0 +1,3 @@
+/* tslint:disable */
+/* eslint-disable */
+export function causes_error(): number;
diff --git a/crates/cli/tests/reference/intrinsic-only.js b/crates/cli/tests/reference/intrinsic-only.js
new file mode 100644
index 00000000000..26525348f80
--- /dev/null
+++ b/crates/cli/tests/reference/intrinsic-only.js
@@ -0,0 +1,57 @@
+let wasm;
+export function __wbg_set_wasm(val) {
+    wasm = val;
+}
+
+
+const lTextDecoder = typeof TextDecoder === 'undefined' ? (0, module.require)('util').TextDecoder : TextDecoder;
+
+let cachedTextDecoder = new lTextDecoder('utf-8', { ignoreBOM: true, fatal: true });
+
+cachedTextDecoder.decode();
+
+let cachedUint8ArrayMemory0 = null;
+
+function getUint8ArrayMemory0() {
+    if (cachedUint8ArrayMemory0 === null || cachedUint8ArrayMemory0.byteLength === 0) {
+        cachedUint8ArrayMemory0 = new Uint8Array(wasm.memory.buffer);
+    }
+    return cachedUint8ArrayMemory0;
+}
+
+function getStringFromWasm0(ptr, len) {
+    ptr = ptr >>> 0;
+    return cachedTextDecoder.decode(getUint8ArrayMemory0().subarray(ptr, ptr + len));
+}
+
+function takeFromExternrefTable0(idx) {
+    const value = wasm.__wbindgen_export_0.get(idx);
+    wasm.__externref_table_dealloc(idx);
+    return value;
+}
+/**
+ * @returns {number}
+ */
+export function causes_error() {
+    const ret = wasm.causes_error();
+    if (ret[2]) {
+        throw takeFromExternrefTable0(ret[1]);
+    }
+    return ret[0];
+}
+
+export function __wbindgen_init_externref_table() {
+    const table = wasm.__wbindgen_export_0;
+    const offset = table.grow(4);
+    table.set(0, undefined);
+    table.set(offset + 0, undefined);
+    table.set(offset + 1, null);
+    table.set(offset + 2, true);
+    table.set(offset + 3, false);
+    ;
+};
+
+export function __wbindgen_throw(arg0, arg1) {
+    throw new Error(getStringFromWasm0(arg0, arg1));
+};
+
diff --git a/crates/cli/tests/reference/intrinsic-only.rs b/crates/cli/tests/reference/intrinsic-only.rs
new file mode 100644
index 00000000000..2dc264ef2b4
--- /dev/null
+++ b/crates/cli/tests/reference/intrinsic-only.rs
@@ -0,0 +1,6 @@
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+pub fn causes_error() -> Result<f64, JsError> {
+    Ok(1.0)
+}
diff --git a/crates/cli/tests/reference/intrinsic-only.wat b/crates/cli/tests/reference/intrinsic-only.wat
new file mode 100644
index 00000000000..8f0b95f09dc
--- /dev/null
+++ b/crates/cli/tests/reference/intrinsic-only.wat
@@ -0,0 +1,17 @@
+(module $reference_test.wasm
+  (type (;0;) (func))
+  (type (;1;) (func (result f64 i32 i32)))
+  (type (;2;) (func (param i32)))
+  (import "./reference_test_bg.js" "__wbindgen_init_externref_table" (func (;0;) (type 0)))
+  (func $__externref_table_dealloc (;1;) (type 2) (param i32))
+  (func $"causes_error multivalue shim" (;2;) (type 1) (result f64 i32 i32))
+  (table (;0;) 128 externref)
+  (memory (;0;) 17)
+  (export "memory" (memory 0))
+  (export "causes_error" (func $"causes_error multivalue shim"))
+  (export "__wbindgen_export_0" (table 0))
+  (export "__externref_table_dealloc" (func $__externref_table_dealloc))
+  (export "__wbindgen_start" (func 0))
+  (@custom "target_features" (after code) "\04+\0amultivalue+\0fmutable-globals+\0freference-types+\08sign-ext")
+)
+
diff --git a/crates/externref-xform/src/lib.rs b/crates/externref-xform/src/lib.rs
index 018f2f96716..6d4688bf2b8 100644
--- a/crates/externref-xform/src/lib.rs
+++ b/crates/externref-xform/src/lib.rs
@@ -302,12 +302,6 @@ impl Transform<'_> {
         self.process_elements(module)?;
         assert!(self.cx.new_elements.is_empty());
 
-        // If we didn't actually transform anything, no need to inject or
-        // rewrite anything from below.
-        if self.shims.is_empty() {
-            return Ok(());
-        }
-
         // Perform all instruction transformations to rewrite calls between
         // functions and make sure everything is still hooked up right.
         self.rewrite_calls(module)?;