From 35d78c0005201383c9e2cf5069be420037438b7c Mon Sep 17 00:00:00 2001
From: Sam Clegg <sbc@chromium.org>
Date: Tue, 10 Sep 2024 16:15:06 -0700
Subject: [PATCH] Add some sanity checks when using `__i53abi` decorator

See #21335
---
 src/jsifier.mjs       | 10 ++++++++++
 src/library_webgpu.js |  5 ++++-
 test/test_other.py    | 20 ++++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/jsifier.mjs b/src/jsifier.mjs
index 15270ce00511b..eba2ba29b08b4 100644
--- a/src/jsifier.mjs
+++ b/src/jsifier.mjs
@@ -299,6 +299,16 @@ function(${args}) {
 
     const sig = LibraryManager.library[symbol + '__sig'];
     const i53abi = LibraryManager.library[symbol + '__i53abi'];
+    if (i53abi) {
+      if (!sig) {
+        error(`JS library error: '__i53abi' decorator requires '__sig' decorator: '${symbol}'`);
+      }
+      if (!sig.includes('j')) {
+        error(
+          `JS library error: '__i53abi' only makes sense when '__sig' includes 'j' (int64): '${symbol}'`,
+        );
+      }
+    }
     if (
       sig &&
       ((i53abi && sig.includes('j')) || ((MEMORY64 || CAN_ADDRESS_2GB) && sig.includes('p')))
diff --git a/src/library_webgpu.js b/src/library_webgpu.js
index 9af4766242ac5..e7f7ba55dd4ce 100644
--- a/src/library_webgpu.js
+++ b/src/library_webgpu.js
@@ -2883,7 +2883,10 @@ for (var value in LibraryWebGPU.$WebGPU.FeatureName) {
 
 for (const key of Object.keys(LibraryWebGPU)) {
   if (typeof LibraryWebGPU[key] === 'function') {
-    LibraryWebGPU[key + '__i53abi'] = true;
+    const sig = LibraryWebGPU[key + '__sig'];
+    if (sig?.includes('j')) {
+      LibraryWebGPU[key + '__i53abi'] = true;
+    }
   }
 }
 
diff --git a/test/test_other.py b/test/test_other.py
index 3214b22455fe0..a2d5cc8e68f58 100644
--- a/test/test_other.py
+++ b/test/test_other.py
@@ -4677,6 +4677,26 @@ def test_js_lib_invalid_decorator(self):
     err = self.expect_fail([EMCC, test_file('hello_world.c'), '--js-library', 'lib.js'])
     self.assertContained("lib.js: Decorator (jslibfunc__async} has wrong type. Expected 'boolean' not 'string'", err)
 
+  def test_js_lib_i53abi(self):
+    create_file('lib.js', r'''
+mergeInto(LibraryManager.library, {
+  jslibfunc__i53abi: true,
+  jslibfunc: (x) => { return 42 },
+});
+''')
+    err = self.expect_fail([EMCC, test_file('hello_world.c'), '-sDEFAULT_LIBRARY_FUNCS_TO_INCLUDE=jslibfunc', '--js-library', 'lib.js'])
+    self.assertContained("error: JS library error: '__i53abi' decorator requires '__sig' decorator: 'jslibfunc'", err)
+
+    create_file('lib.js', r'''
+mergeInto(LibraryManager.library, {
+  jslibfunc__i53abi: true,
+  jslibfunc__sig: 'ii',
+  jslibfunc: (x) => { return 42 },
+});
+''')
+    err = self.expect_fail([EMCC, test_file('hello_world.c'), '-sDEFAULT_LIBRARY_FUNCS_TO_INCLUDE=jslibfunc', '--js-library', 'lib.js'])
+    self.assertContained("error: JS library error: '__i53abi' only makes sense when '__sig' includes 'j' (int64): 'jslibfunc'", err)
+
   def test_js_lib_legacy(self):
     create_file('lib.js', r'''
 mergeInto(LibraryManager.library, {