Revert "Wasm-bindgen abi compat using cast_to"

This reverts commit 903c553f4a.

compiler/rustc_middle/src/ty/layout.rs

@@ -2860,7 +2860,7 @@ where
             return;
         }
 
-        if let Err(msg) = self.adjust_for_cabi(cx, &cx.tcx().sess.target_features, abi) {
+        if let Err(msg) = self.adjust_for_cabi(cx, abi) {
             cx.tcx().sess.fatal(&msg);
         }
     }

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

@@ -53,8 +53,6 @@ pub enum PassMode {
 // Hack to disable non_upper_case_globals only for the bitflags! and not for the rest
 // of this module
 pub use attr_impl::ArgAttribute;
-use rustc_data_structures::stable_set::FxHashSet;
-use rustc_span::Symbol;
 
 #[allow(non_upper_case_globals)]
 #[allow(unused)]
@@ -594,12 +592,7 @@ pub struct FnAbi<'a, Ty> {
 }
 
 impl<'a, Ty> FnAbi<'a, Ty> {
-    pub fn adjust_for_cabi<C>(
+    pub fn adjust_for_cabi<C>(&mut self, cx: &C, abi: spec::abi::Abi) -> Result<(), String>
-        &mut self,
-        cx: &C,
-        target_features: &FxHashSet<Symbol>,
-        abi: spec::abi::Abi,
-    ) -> Result<(), String>
     where
         Ty: TyAndLayoutMethods<'a, C> + Copy,
         C: LayoutOf<Ty = Ty, TyAndLayout = TyAndLayout<'a, Ty>> + HasDataLayout + HasTargetSpec,
@@ -640,7 +633,7 @@ impl<'a, Ty> FnAbi<'a, Ty> {
             "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(cx, target_features, self),
+                _ => wasm32_bindgen_compat::compute_abi_info(self),
             },
             "asmjs" => wasm32::compute_abi_info(cx, self),
             a => return Err(format!("unrecognized arch \"{}\" in target specification", a)),

compiler/rustc_target/src/abi/call/wasm32_bindgen_compat.rs

@@ -5,58 +5,25 @@
 // can be fixed to work with the correct ABI. See #63649 for further
 // discussion.
 
-use rustc_data_structures::stable_set::FxHashSet;
+use crate::abi::call::{ArgAbi, FnAbi};
-use rustc_span::Symbol;
 
-use crate::abi::call::{ArgAbi, FnAbi, Uniform};
+fn classify_ret<Ty>(ret: &mut ArgAbi<'_, Ty>) {
-use crate::abi::{HasDataLayout, LayoutOf, TyAndLayout, TyAndLayoutMethods};
-
-fn classify_ret<'a, Ty, C>(cx: &C, target_features: &FxHashSet<Symbol>, ret: &mut ArgAbi<'a, Ty>)
-where
-    Ty: TyAndLayoutMethods<'a, C> + Copy,
-    C: LayoutOf<Ty = Ty, TyAndLayout = TyAndLayout<'a, Ty>> + HasDataLayout,
-{
-    if ret.layout.is_aggregate() {
-        if let Some(unit) = ret.layout.homogeneous_aggregate(cx).ok().and_then(|ha| ha.unit()) {
-            let size = ret.layout.size;
-            if unit.size == size || target_features.contains(&Symbol::intern("multivalue")) {
-                ret.cast_to(Uniform { unit, total: size });
-            }
-        }
-    }
     ret.extend_integer_width_to(32);
 }
 
-fn classify_arg<'a, Ty, C>(cx: &C, arg: &mut ArgAbi<'a, Ty>)
+fn classify_arg<Ty>(arg: &mut ArgAbi<'_, Ty>) {
-where
-    Ty: TyAndLayoutMethods<'a, C> + Copy,
-    C: LayoutOf<Ty = Ty, TyAndLayout = TyAndLayout<'a, Ty>> + HasDataLayout,
-{
-    if arg.layout.is_aggregate() {
-        if let Some(unit) = arg.layout.homogeneous_aggregate(cx).ok().and_then(|ha| ha.unit()) {
-            let size = arg.layout.size;
-            arg.cast_to(Uniform { unit, total: size });
-        }
-    }
     arg.extend_integer_width_to(32);
 }
 
-pub fn compute_abi_info<'a, Ty, C>(
+pub fn compute_abi_info<Ty>(fn_abi: &mut FnAbi<'_, Ty>) {
-    cx: &C,
-    target_features: &FxHashSet<Symbol>,
-    fn_abi: &mut FnAbi<'a, Ty>,
-) where
-    Ty: TyAndLayoutMethods<'a, C> + Copy,
-    C: LayoutOf<Ty = Ty, TyAndLayout = TyAndLayout<'a, Ty>> + HasDataLayout,
-{
     if !fn_abi.ret.is_ignore() {
-        classify_ret(cx, target_features, &mut fn_abi.ret);
+        classify_ret(&mut fn_abi.ret);
     }
 
     for arg in &mut fn_abi.args {
         if arg.is_ignore() {
             continue;
         }
-        classify_arg(cx, arg);
+        classify_arg(arg);
     }
 }