Share wasm-bindgen compat abi selection code

Author: bjorn3

compiler/rustc_middle/src/ty/layout.rs

@@ -2752,7 +2752,7 @@ where
                 attrs
             });
 
-            if target.arch == "wasm32" && target.os == "unknown" {
+            if call::use_wasm_bindgen_compat_abi(target) {
                 // wasm-bindgen depends on ABI details and is incompatible with the
                 // correct C ABI, so this is being kept around until wasm-bindgen
                 // can be fixed to work with the correct ABI. See #63649 for further

compiler/rustc_target/src/abi/call/mod.rs

@@ -1,6 +1,6 @@
 use crate::abi::{self, Abi, Align, FieldsShape, Size};
 use crate::abi::{HasDataLayout, LayoutOf, TyAndLayout, TyAndLayoutMethods};
-use crate::spec::{self, HasTargetSpec};
+use crate::spec::{self, HasTargetSpec, Target};
 
 mod aarch64;
 mod amdgpu;
@@ -631,9 +631,10 @@ impl<'a, Ty> FnAbi<'a, Ty> {
             "nvptx64" => nvptx64::compute_abi_info(self),
             "hexagon" => hexagon::compute_abi_info(self),
             "riscv32" | "riscv64" => riscv::compute_abi_info(cx, self),
-            "wasm32" => match cx.target_spec().os.as_str() {
-                "emscripten" | "wasi" => wasm32::compute_abi_info(cx, self),
-                _ => wasm32_bindgen_compat::compute_abi_info(self),
+            "wasm32" => if use_wasm_bindgen_compat_abi(cx.target_spec()) {
+                wasm32_bindgen_compat::compute_abi_info(self)
+            } else {
+                wasm32::compute_abi_info(cx, self)
             },
             "asmjs" => wasm32::compute_abi_info(cx, self),
             a => return Err(format!("unrecognized arch \"{}\" in target specification", a)),
@@ -642,3 +643,14 @@ impl<'a, Ty> FnAbi<'a, Ty> {
         Ok(())
     }
 }
+
+pub fn use_wasm_bindgen_compat_abi(target_spec: &Target) -> bool {
+    if target_spec.arch.as_str() == "wasm32" {
+        match target_spec.os.as_str() {
+            "emscripten" | "wasi" => false,
+            _ => true,
+        }
+    } else {
+        false
+    }
+}