From f1d89a4a3417bca142fbaa3b0ab9dad7d49a1d63 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Mon, 12 Feb 2024 08:42:22 -0600
Subject: [PATCH] Remove usage of `AtomicU64` in `wasmparser` (#1412)

Instead substitute this with `AtomicUsize` which panics on overflow to
catch any possible issues on 32-bit platforms. This is motivated by
https://github.com/rust-lang/rust/pull/120588 which is pulling
`wasmparser` into the Rust compiler and `AtomicU64` is not available on
all the platforms the compiler itself is built for.

I plan on backporting this to the `0.118.x` release track as well which
is what's used by the `object` crate currently to avoid the need for a
whole bunch of cascading updates.
---
 crates/wasmparser/src/validator/types.rs | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/crates/wasmparser/src/validator/types.rs b/crates/wasmparser/src/validator/types.rs
index acab322d17..043469f58a 100644
--- a/crates/wasmparser/src/validator/types.rs
+++ b/crates/wasmparser/src/validator/types.rs
@@ -14,7 +14,7 @@ use indexmap::{IndexMap, IndexSet};
 use std::collections::hash_map::Entry;
 use std::collections::{HashMap, HashSet};
 use std::ops::{Index, Range};
-use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::atomic::{AtomicUsize, Ordering};
 use std::{
     borrow::Borrow,
     hash::{Hash, Hasher},
@@ -1451,7 +1451,7 @@ pub struct ResourceId {
     // per resource id is probably too expensive. To amortize that cost each
     // top-level wasm component gets a single globally unique identifier, and
     // then within a component contextually unique identifiers are handed out.
-    globally_unique_id: u64,
+    globally_unique_id: usize,
 
     // A contextually unique id within the globally unique id above. This is
     // allocated within a `TypeAlloc` with its own counter, and allocations of
@@ -2925,7 +2925,7 @@ pub(crate) struct TypeAlloc {
 
     // This is assigned at creation of a `TypeAlloc` and then never changed.
     // It's used in one entry for all `ResourceId`s contained within.
-    globally_unique_id: u64,
+    globally_unique_id: usize,
 
     // This is a counter that's incremeneted each time `alloc_resource_id` is
     // called.
@@ -2934,10 +2934,17 @@ pub(crate) struct TypeAlloc {
 
 impl Default for TypeAlloc {
     fn default() -> TypeAlloc {
-        static NEXT_GLOBAL_ID: AtomicU64 = AtomicU64::new(0);
+        static NEXT_GLOBAL_ID: AtomicUsize = AtomicUsize::new(0);
         let mut ret = TypeAlloc {
             list: TypeList::default(),
-            globally_unique_id: NEXT_GLOBAL_ID.fetch_add(1, Ordering::Relaxed),
+            globally_unique_id: {
+                let id = NEXT_GLOBAL_ID.fetch_add(1, Ordering::Relaxed);
+                if id > usize::MAX - 10_000 {
+                    NEXT_GLOBAL_ID.store(usize::MAX - 10_000, Ordering::Relaxed);
+                    panic!("overflow on the global id counter");
+                }
+                id
+            },
             next_resource_id: 0,
         };
         ret.list.canonical_rec_groups = Some(Default::default());