update to rustc 1.99.0

.cargo/config.toml

@@ -45,7 +45,6 @@ rustflags = [
     "-Wclippy::flat_map_option",
     "-Wclippy::float_cmp_const",
     "-Wclippy::fn_params_excessive_bools",
-    "-Wclippy::from_iter_instead_of_collect",
     "-Wclippy::if_let_mutex",
     "-Wclippy::implicit_clone",
     "-Wclippy::imprecise_flops",

crates/rustc_codegen_spirv/build.rs

@@ -19,9 +19,9 @@ use std::{env, fs, mem};
 /// `cargo publish`. We need to figure out a way to do this properly, but let's hardcode it for now :/
 //const REQUIRED_RUST_TOOLCHAIN: &str = include_str!("../../rust-toolchain.toml");
 const REQUIRED_RUST_TOOLCHAIN: &str = r#"[toolchain]
-channel = "nightly-2026-05-22"
+channel = "nightly-2026-08-06"
 components = ["rust-src", "rustc-dev", "llvm-tools"]
-# commit_hash = e96c36b6f76833388c519561d145492d2c08db4e"#;
+# commit_hash = 7608eb7b07eaf93f16d7cf5bcb2098eca87503df"#;
 
 fn rustc_output(arg: &str) -> Result<String, Box<dyn Error>> {
     let rustc = env::var("RUSTC").unwrap_or_else(|_| "rustc".into());
@@ -153,7 +153,10 @@ fn generate_pqp_cg_ssa() -> Result<(), Box<dyn Error>> {
                 for line in mem::take(&mut src).lines() {
                     if line.starts_with("#!") {
                         src += "// ";
-                        if !line.starts_with("#![doc(") && line != "#![warn(unreachable_pub)]" {
+                        if !line.starts_with("#![doc(")
+                            && line != "#![warn(unreachable_pub)]"
+                            && !line.starts_with("#![cfg_attr(bootstrap,")
+                        {
                             writeln(&mut cg_ssa_lib_rc_attrs, line);
                         }
                     } else if line == "#[macro_use]" || line.starts_with("extern crate ") {
@@ -256,6 +259,34 @@ pub(super) fn elf_e_flags(architecture: Architecture, sess: &Session) -> u32 {",
                 );
             }
 
+            // HACK(firestar99): Undo code cleanup that prevents passing ScalarPairs as `PassMode::Direct`
+            // https://github.com/rust-lang/rust/commit/dfc475d018c780475ea962f15d86cfa05a50a148
+            if relative_path == Path::new("src/mir/mod.rs") {
+                src = src.replace(
+                    "
+                        debug_assert!(bx.is_backend_immediate(arg.layout));
+                        return local(OperandRef {
+                            val: OperandValue::Immediate(llarg),
+                            layout: arg.layout,
+                            move_annotation: None,
+                        });",
+                    "
+                        return local(OperandRef::from_immediate_or_packed_pair(
+                            bx, llarg, arg.layout,
+                        ));",
+                );
+                src = src.replace("fx.fill_function_debug_context(&mut start_bx);", "");
+            }
+            if relative_path == Path::new("src/mir/block.rs") {
+                src = src.replace(
+                    r#"
+                PassMode::Direct(_) => (op.immediate(), arg.layout.align.abi, false),
+                PassMode::Ignore | PassMode::Pair(..) => unreachable!("handled above"),"#,
+                    "\
+                _ => (op.immediate_or_packed_pair(bx), arg.layout.align.abi, false),",
+                );
+            }
+
             fs::write(out_path, src)?;
         }
     }

crates/rustc_codegen_spirv/src/abi.rs

@@ -87,20 +87,11 @@ pub(crate) fn provide(providers: &mut Providers) {
         fn_abi: &'tcx FnAbi<'tcx, Ty<'tcx>>,
     ) -> &'tcx FnAbi<'tcx, Ty<'tcx>> {
         let readjust_arg_abi = |arg: &ArgAbi<'tcx, Ty<'tcx>>| {
-            let mut arg = ArgAbi::new(&tcx, arg.layout, |_, _| ArgAttributes::new());
+            let mut arg = ArgAbi::new(arg.layout, |_, _| ArgAttributes::new());
             // FIXME: this is bad! https://github.com/rust-lang/rust/issues/115666
             // <https://github.com/rust-lang/rust/commit/eaaa03faf77b157907894a4207d8378ecaec7b45>
             arg.make_direct_deprecated();
 
-            // FIXME(eddyb) detect `#[rust_gpu::vector::v1]` more specifically,
-            // to avoid affecting anything should actually be passed as a pair.
-            if let PassMode::Pair(..) = arg.mode {
-                // HACK(eddyb) this avoids breaking e.g. `&[T]` pairs.
-                if let TyKind::Adt(..) = arg.layout.ty.kind() {
-                    arg.mode = PassMode::Direct(ArgAttributes::new());
-                }
-            }
-
             // Avoid pointlessly passing ZSTs, just like the official Rust ABI.
             if arg.layout.is_zst() {
                 arg.mode = PassMode::Ignore;
@@ -364,7 +355,7 @@ impl<'tcx> ConvSpirvType<'tcx> for TyAndLayout<'tcx> {
             }
             .def_with_name(cx, span, TyLayoutNameKey::from(*self)),
             BackendRepr::Scalar(scalar) => trans_scalar(cx, span, *self, scalar, Size::ZERO),
-            BackendRepr::ScalarPair(a, b) => {
+            BackendRepr::ScalarPair { a, b, .. } => {
                 // NOTE(eddyb) unlike `BackendRepr::Scalar`'s simpler newtype-unpacking
                 // behavior, `BackendRepr::ScalarPair` can be composed in two ways:
                 // * two `BackendRepr::Scalar` fields (and any number of ZST fields),
@@ -402,7 +393,10 @@ impl<'tcx> ConvSpirvType<'tcx> for TyAndLayout<'tcx> {
                 // Note: We can't use auto_struct_layout here because the spirv types here might be undefined due to
                 // recursive pointer types.
                 let a_offset = Size::ZERO;
-                let b_offset = a.primitive().size(cx).align_to(b.primitive().align(cx).abi);
+                let b_offset = a
+                    .primitive()
+                    .size(cx)
+                    .align_to(b.primitive().default_align(cx).abi);
                 let a = trans_scalar(cx, span, *self, a, a_offset);
                 let b = trans_scalar(cx, span, *self, b, b_offset);
                 let size = if self.is_unsized() {
@@ -438,7 +432,7 @@ impl<'tcx> ConvSpirvType<'tcx> for TyAndLayout<'tcx> {
                 let elem_spirv = trans_scalar(cx, span, *self, element, Size::ZERO);
                 SpirvType::Vector {
                     element: elem_spirv,
-                    count: count as u32,
+                    count: count.as_u32(),
                     size: self.size,
                     align: self.align.abi,
                 }
@@ -461,8 +455,8 @@ pub fn scalar_pair_element_backend_type<'tcx>(
     ty: TyAndLayout<'tcx>,
     index: usize,
 ) -> Word {
-    let [a, b] = match ty.layout.backend_repr() {
-        BackendRepr::ScalarPair(a, b) => [a, b],
+    let [a, b] = match ty.backend_repr {
+        BackendRepr::ScalarPair { a, b, .. } => [a, b],
         other => span_bug!(
             span,
             "scalar_pair_element_backend_type invalid abi: {:?}",
@@ -471,7 +465,10 @@ pub fn scalar_pair_element_backend_type<'tcx>(
     };
     let offset = match index {
         0 => Size::ZERO,
-        1 => a.primitive().size(cx).align_to(b.primitive().align(cx).abi),
+        1 => a
+            .primitive()
+            .size(cx)
+            .align_to(b.primitive().default_align(cx).abi),
         _ => unreachable!(),
     };
     trans_scalar(cx, span, ty, [a, b][index], offset)

crates/rustc_codegen_spirv/src/attr.rs

@@ -7,7 +7,7 @@ use crate::symbols::Symbols;
 use rspirv::spirv::{BuiltIn, ExecutionMode, ExecutionModel, StorageClass};
 use rustc_ast::{LitKind, MetaItemInner, MetaItemLit};
 use rustc_hir as hir;
-use rustc_hir::def_id::LocalModDefId;
+use rustc_hir::def_id::LocalModId;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{Attribute, CRATE_HIR_ID, HirId, MethodKind, Target};
 use rustc_middle::hir::nested_filter;
@@ -433,19 +433,19 @@ impl<'tcx> Visitor<'tcx> for CheckSpirvAttrVisitor<'tcx> {
     }
 
     fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
-        let target = Target::from_item(item);
+        let target = Target::from(item);
         self.check_spirv_attributes(item.hir_id(), target);
         intravisit::walk_item(self, item);
     }
 
     fn visit_generic_param(&mut self, generic_param: &'tcx hir::GenericParam<'tcx>) {
-        let target = Target::from_generic_param(generic_param);
+        let target = Target::from(generic_param);
         self.check_spirv_attributes(generic_param.hir_id, target);
         intravisit::walk_generic_param(self, generic_param);
     }
 
     fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
-        let target = Target::from_trait_item(trait_item);
+        let target = Target::from(trait_item);
         self.check_spirv_attributes(trait_item.hir_id(), target);
         intravisit::walk_trait_item(self, trait_item);
     }
@@ -461,7 +461,7 @@ impl<'tcx> Visitor<'tcx> for CheckSpirvAttrVisitor<'tcx> {
     }
 
     fn visit_foreign_item(&mut self, f_item: &'tcx hir::ForeignItem<'tcx>) {
-        let target = Target::from_foreign_item(f_item);
+        let target = Target::from(f_item);
         self.check_spirv_attributes(f_item.hir_id(), target);
         intravisit::walk_foreign_item(self, f_item);
     }
@@ -503,7 +503,7 @@ impl<'tcx> Visitor<'tcx> for CheckSpirvAttrVisitor<'tcx> {
 }
 
 // FIXME(eddyb) DRY this somehow and make it reusable from somewhere in `rustc`.
-fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
+fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalModId) {
     let check_spirv_attr_visitor = &mut CheckSpirvAttrVisitor {
         tcx,
         sym: Symbols::get(),

crates/rustc_codegen_spirv/src/builder/builder_methods.rs

@@ -1873,7 +1873,7 @@ impl<'a, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'tcx> {
         self.bitcast(loaded_val, ty)
     }
 
-    fn volatile_load(&mut self, ty: Self::Type, ptr: Self::Value) -> Self::Value {
+    fn volatile_load(&mut self, ty: Self::Type, ptr: Self::Value, _align: Align) -> Self::Value {
         // TODO: Implement this
         let result = self.load(ty, ptr, Align::from_bytes(0).unwrap());
         self.zombie(result.def(self), "volatile load is not supported yet");
@@ -1917,18 +1917,18 @@ impl<'a, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'tcx> {
 
         let val = if place.val.llextra.is_some() {
             OperandValue::Ref(place.val)
-        } else if self.cx.is_backend_immediate(place.layout) {
+        } else if place.layout.backend_repr.is_scalar_or_simd() {
             let llval = self.load(
                 place.layout.spirv_type(self.span(), self),
                 place.val.llval,
                 place.val.align,
             );
             OperandValue::Immediate(llval)
-        } else if let BackendRepr::ScalarPair(a, b) = place.layout.backend_repr {
+        } else if let BackendRepr::ScalarPair { a, b, .. } = place.layout.backend_repr {
             let b_offset = a
                 .primitive()
                 .size(self)
-                .align_to(b.primitive().align(self).abi);
+                .align_to(b.primitive().default_align(self).abi);
 
             let mut load = |i, scalar: Scalar, align| {
                 let llptr = if i == 0 {
@@ -2012,7 +2012,8 @@ impl<'a, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'tcx> {
         align: Align,
         flags: MemFlags,
     ) -> Self::Value {
-        if flags != MemFlags::empty() {
+        let allowed_flags = MemFlags::CAPTURES_READ_ONLY;
+        if !(flags & !allowed_flags).is_empty() {
             self.err(format!("store_with_flags is not supported yet: {flags:?}"));
         }
         self.store(val, ptr, align)
@@ -3503,4 +3504,8 @@ impl<'a, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'tcx> {
     fn alloca_with_ty(&mut self, _layout: TyAndLayout<'tcx>) -> Self::Value {
         bug!("scalable alloca is not supported in SPIR-V backend")
     }
+
+    fn vscale(&mut self, _ty: Self::Type) -> Self::Value {
+        self.fatal("scalable vectors not supported");
+    }
 }

crates/rustc_codegen_spirv/src/builder/format_args_decompiler.rs

@@ -557,35 +557,60 @@ impl<'tcx> DecodedFormatArgs<'tcx> {
             if let Some((template_id, template_ty_id, rt_args_ptr_id, rt_args_ptr_ty_id)) =
                 split_fmt_args
             {
-                let ctor = if let (Some(template_len), Some(rt_args_count)) = (
+                if let (Some(template_len), Some(rt_args_count)) = (
                     const_ptr_to_composite_len(template_id)
                         .or_else(|| array_len_from_ptr_type(template_ty_id)),
                     const_ptr_to_composite_len(rt_args_ptr_id)
                         .or_else(|| array_len_from_ptr_type(rt_args_ptr_ty_id)),
                 ) {
-                    FmtArgsCtor::NewTemplate {
-                        template_len,
-                        rt_args_count,
-                    }
+                    (
+                        FmtArgsCtor::NewTemplate {
+                            template_len,
+                            rt_args_count,
+                        },
+                        SmallVec::<[Word; 8]>::from_slice(&[template_id, rt_args_ptr_id]),
+                    )
                 } else if let Some(&[Inst::Call(_, callee_id, ref call_args)]) =
                     try_rev_take(-1).as_deref()
                     && call_args.len() == 2
                     && [call_args[0], call_args[1]] == [template_id, rt_args_ptr_id]
                 {
                     // Consume the matched call instruction.
                     try_rev_take(1).unwrap();
-                    lookup_fmt_args_ctor(callee_id)?
+                    (
+                        lookup_fmt_args_ctor(callee_id)?,
+                        SmallVec::<[Word; 8]>::from_slice(&[template_id, rt_args_ptr_id]),
+                    )
+                } else if let Some(
+                    &[
+                        Inst::Call(call_ret_id, callee_id, ref call_args),
+                        Inst::CompositeExtract(extracted0, from0, 0),
+                        Inst::CompositeExtract(extracted1, from1, 1),
+                    ],
+                ) = try_rev_take(-3).as_deref()
+                    && [from0, from1] == [call_ret_id; 2]
+                    && [extracted0, extracted1] == [template_id, rt_args_ptr_id]
+                {
+                    // Newer rustc, since `BackendRepr::ScalarPair` args are no
+                    // longer forced to `PassMode::Direct`, returns the whole
+                    // `fmt::Arguments` from its `new_*` constructor as a scalar
+                    // pair, and splits it (via `OpCompositeExtract`s) into the
+                    // two scalar values passed to the panic entry-point.
+                    //
+                    // The constructor's own arguments (i.e. `pieces`/`template`
+                    // and the `rt::Argument` slice pointers) still carry the
+                    // recoverable const data, so use those, like the aggregate
+                    // (non-split) `Call`+`extract`+`insert` case does below.
+                    let call_args_storage = call_args.iter().copied().collect();
+                    // Consume the matched call + both `OpCompositeExtract`s.
+                    try_rev_take(3).unwrap();
+                    (lookup_fmt_args_ctor(callee_id)?, call_args_storage)
                 } else {
                     // We failed to recover constructor metadata for an already-split
                     // `fmt::Arguments` value. Keep panic lowering sound by falling
                     // back to an unknown panic message, without requiring decompilation.
                     return Ok(decoded_format_args);
-                };
-
-                (
-                    ctor,
-                    SmallVec::<[Word; 8]>::from_slice(&[template_id, rt_args_ptr_id]),
-                )
+                }
             } else {
                 // Newer rustc can pass the `fmt::Arguments::new_*` result directly to
                 // panic entry points (single trailing call), while older versions go