1.88.0?

1 files changed, 611 insertions, 0 deletions

diff --git a/dev-lang/rust/files/rust-no-alloc-shim-func.patch b/dev-lang/rust/files/rust-no-alloc-shim-func.patch
new file mode 100644
index 0000000..ecdadb2
--- /dev/null
+++ b/dev-lang/rust/files/rust-no-alloc-shim-func.patch
@@ -0,0 +1,611 @@
+From 6906b44e1c667705ce04626901a75d51f4910de3 Mon Sep 17 00:00:00 2001
+From: Daniel Paoliello <danpao@microsoft.com>
+Date: Thu, 15 May 2025 16:38:46 -0700
+Subject: [PATCH] Change __rust_no_alloc_shim_is_unstable to be a function
+
+---
+ compiler/rustc_ast/src/expand/allocator.rs    |  2 +-
+ .../rustc_codegen_cranelift/src/allocator.rs  | 40 +++++++---
+ compiler/rustc_codegen_gcc/src/allocator.rs   | 78 ++++++++++---------
+ compiler/rustc_codegen_llvm/src/allocator.rs  | 74 ++++++++++--------
+ .../src/back/symbol_export.rs                 | 14 +---
+ compiler/rustc_symbol_mangling/src/v0.rs      |  4 -
+ library/alloc/src/alloc.rs                    |  7 +-
+ src/tools/miri/src/shims/extern_static.rs     |  4 -
+ src/tools/miri/src/shims/foreign_items.rs     |  4 +
+ tests/codegen/alloc-optimisation.rs           |  3 +-
+ tests/codegen/unwind-landingpad-inline.rs     |  6 +-
+ tests/codegen/vec-iter-collect-len.rs         |  6 +-
+ tests/codegen/vec-optimizes-away.rs           |  3 +-
+ tests/run-make/no-alloc-shim/foo.rs           |  6 +-
+ tests/run-make/no-alloc-shim/rmake.rs         | 22 ++++--
+ tests/run-make/symbols-all-mangled/rmake.rs   |  8 --
+ tests/ui/sanitizer/dataflow-abilist.txt       |  1 +
+ 18 files changed, 155 insertions(+), 131 deletions(-)
+
+diff --git a/compiler/rustc_ast/src/expand/allocator.rs b/compiler/rustc_ast/src/expand/allocator.rs
+index dd8d5ae624a3c..7dee2ed17b4be 100644
+--- a/compiler/rustc_ast/src/expand/allocator.rs
++++ b/compiler/rustc_ast/src/expand/allocator.rs
+@@ -22,7 +22,7 @@ pub fn alloc_error_handler_name(alloc_error_handler_kind: AllocatorKind) -> &'st
+     }
+ }
+ 
+-pub const NO_ALLOC_SHIM_IS_UNSTABLE: &str = "__rust_no_alloc_shim_is_unstable";
++pub const NO_ALLOC_SHIM_IS_UNSTABLE: &str = "__rust_no_alloc_shim_is_unstable_v2";
+ 
+ pub enum AllocatorTy {
+     Layout,
+diff --git a/compiler/rustc_codegen_cranelift/src/allocator.rs b/compiler/rustc_codegen_cranelift/src/allocator.rs
+index 9cff8a84db3d9..ffb932a3c38e6 100644
+--- a/compiler/rustc_codegen_cranelift/src/allocator.rs
++++ b/compiler/rustc_codegen_cranelift/src/allocator.rs
+@@ -1,6 +1,7 @@
+ //! Allocator shim
+ // Adapted from rustc
+ 
++use cranelift_frontend::{FunctionBuilder, FunctionBuilderContext};
+ use rustc_ast::expand::allocator::{
+     ALLOCATOR_METHODS, AllocatorKind, AllocatorTy, NO_ALLOC_SHIM_IS_UNSTABLE,
+     alloc_error_handler_name, default_fn_name, global_fn_name,
+@@ -97,16 +98,31 @@ fn codegen_inner(
+     data.define(Box::new([val]));
+     module.define_data(data_id, &data).unwrap();
+ 
+-    let data_id = module
+-        .declare_data(
+-            &mangle_internal_symbol(tcx, NO_ALLOC_SHIM_IS_UNSTABLE),
+-            Linkage::Export,
+-            false,
+-            false,
+-        )
+-        .unwrap();
+-    let mut data = DataDescription::new();
+-    data.set_align(1);
+-    data.define(Box::new([0]));
+-    module.define_data(data_id, &data).unwrap();
++    {
++        let sig = Signature {
++            call_conv: module.target_config().default_call_conv,
++            params: vec![],
++            returns: vec![],
++        };
++        let func_id = module
++            .declare_function(
++                &mangle_internal_symbol(tcx, NO_ALLOC_SHIM_IS_UNSTABLE),
++                Linkage::Export,
++                &sig,
++            )
++            .unwrap();
++
++        let mut ctx = Context::new();
++        ctx.func.signature = sig;
++        let mut func_ctx = FunctionBuilderContext::new();
++        let mut bcx = FunctionBuilder::new(&mut ctx.func, &mut func_ctx);
++
++        let block = bcx.create_block();
++        bcx.switch_to_block(block);
++        bcx.ins().return_(&[]);
++        bcx.seal_all_blocks();
++        bcx.finalize();
++
++        module.define_function(func_id, &mut ctx).unwrap();
++    }
+ }
+diff --git a/compiler/rustc_codegen_gcc/src/allocator.rs b/compiler/rustc_codegen_gcc/src/allocator.rs
+index f4ebd42ee2dc0..cf8aa500c778f 100644
+--- a/compiler/rustc_codegen_gcc/src/allocator.rs
++++ b/compiler/rustc_codegen_gcc/src/allocator.rs
+@@ -57,7 +57,7 @@ pub(crate) unsafe fn codegen(
+             let from_name = mangle_internal_symbol(tcx, &global_fn_name(method.name));
+             let to_name = mangle_internal_symbol(tcx, &default_fn_name(method.name));
+ 
+-            create_wrapper_function(tcx, context, &from_name, &to_name, &types, output);
++            create_wrapper_function(tcx, context, &from_name, Some(&to_name), &types, output);
+         }
+     }
+ 
+@@ -66,7 +66,7 @@ pub(crate) unsafe fn codegen(
+         tcx,
+         context,
+         &mangle_internal_symbol(tcx, "__rust_alloc_error_handler"),
+-        &mangle_internal_symbol(tcx, alloc_error_handler_name(alloc_error_handler_kind)),
++        Some(&mangle_internal_symbol(tcx, alloc_error_handler_name(alloc_error_handler_kind))),
+         &[usize, usize],
+         None,
+     );
+@@ -81,21 +81,21 @@ pub(crate) unsafe fn codegen(
+     let value = context.new_rvalue_from_int(i8, value as i32);
+     global.global_set_initializer_rvalue(value);
+ 
+-    let name = mangle_internal_symbol(tcx, NO_ALLOC_SHIM_IS_UNSTABLE);
+-    let global = context.new_global(None, GlobalKind::Exported, i8, name);
+-    #[cfg(feature = "master")]
+-    global.add_attribute(VarAttribute::Visibility(symbol_visibility_to_gcc(
+-        tcx.sess.default_visibility(),
+-    )));
+-    let value = context.new_rvalue_from_int(i8, 0);
+-    global.global_set_initializer_rvalue(value);
++    create_wrapper_function(
++        tcx,
++        context,
++        &mangle_internal_symbol(tcx, NO_ALLOC_SHIM_IS_UNSTABLE),
++        None,
++        &[],
++        None,
++    );
+ }
+ 
+ fn create_wrapper_function(
+     tcx: TyCtxt<'_>,
+     context: &Context<'_>,
+     from_name: &str,
+-    to_name: &str,
++    to_name: Option<&str>,
+     types: &[Type<'_>],
+     output: Option<Type<'_>>,
+ ) {
+@@ -124,34 +124,40 @@ fn create_wrapper_function(
+         // TODO(antoyo): emit unwind tables.
+     }
+ 
+-    let args: Vec<_> = types
+-        .iter()
+-        .enumerate()
+-        .map(|(index, typ)| context.new_parameter(None, *typ, format!("param{}", index)))
+-        .collect();
+-    let callee = context.new_function(
+-        None,
+-        FunctionType::Extern,
+-        output.unwrap_or(void),
+-        &args,
+-        to_name,
+-        false,
+-    );
+-    #[cfg(feature = "master")]
+-    callee.add_attribute(FnAttribute::Visibility(gccjit::Visibility::Hidden));
+-
+     let block = func.new_block("entry");
+ 
+-    let args = args
+-        .iter()
+-        .enumerate()
+-        .map(|(i, _)| func.get_param(i as i32).to_rvalue())
+-        .collect::<Vec<_>>();
+-    let ret = context.new_call(None, callee, &args);
+-    //llvm::LLVMSetTailCall(ret, True);
+-    if output.is_some() {
+-        block.end_with_return(None, ret);
++    if let Some(to_name) = to_name {
++        let args: Vec<_> = types
++            .iter()
++            .enumerate()
++            .map(|(index, typ)| context.new_parameter(None, *typ, format!("param{}", index)))
++            .collect();
++        let callee = context.new_function(
++            None,
++            FunctionType::Extern,
++            output.unwrap_or(void),
++            &args,
++            to_name,
++            false,
++        );
++        #[cfg(feature = "master")]
++        callee.add_attribute(FnAttribute::Visibility(gccjit::Visibility::Hidden));
++
++        let args = args
++            .iter()
++            .enumerate()
++            .map(|(i, _)| func.get_param(i as i32).to_rvalue())
++            .collect::<Vec<_>>();
++        let ret = context.new_call(None, callee, &args);
++        //llvm::LLVMSetTailCall(ret, True);
++        if output.is_some() {
++            block.end_with_return(None, ret);
++        } else {
++            block.add_eval(None, ret);
++            block.end_with_void_return(None);
++        }
+     } else {
++        assert!(output.is_none());
+         block.end_with_void_return(None);
+     }
+ 
+diff --git a/compiler/rustc_codegen_llvm/src/allocator.rs b/compiler/rustc_codegen_llvm/src/allocator.rs
+index 4a78e69497994..9dca63cfc8d4f 100644
+--- a/compiler/rustc_codegen_llvm/src/allocator.rs
++++ b/compiler/rustc_codegen_llvm/src/allocator.rs
+@@ -57,7 +57,7 @@ pub(crate) unsafe fn codegen(
+             let from_name = mangle_internal_symbol(tcx, &global_fn_name(method.name));
+             let to_name = mangle_internal_symbol(tcx, &default_fn_name(method.name));
+ 
+-            create_wrapper_function(tcx, &cx, &from_name, &to_name, &args, output, false);
++            create_wrapper_function(tcx, &cx, &from_name, Some(&to_name), &args, output, false);
+         }
+     }
+ 
+@@ -66,7 +66,7 @@ pub(crate) unsafe fn codegen(
+         tcx,
+         &cx,
+         &mangle_internal_symbol(tcx, "__rust_alloc_error_handler"),
+-        &mangle_internal_symbol(tcx, alloc_error_handler_name(alloc_error_handler_kind)),
++        Some(&mangle_internal_symbol(tcx, alloc_error_handler_name(alloc_error_handler_kind))),
+         &[usize, usize], // size, align
+         None,
+         true,
+@@ -81,11 +81,16 @@ pub(crate) unsafe fn codegen(
+         let llval = llvm::LLVMConstInt(i8, val as u64, False);
+         llvm::set_initializer(ll_g, llval);
+ 
+-        let name = mangle_internal_symbol(tcx, NO_ALLOC_SHIM_IS_UNSTABLE);
+-        let ll_g = cx.declare_global(&name, i8);
+-        llvm::set_visibility(ll_g, llvm::Visibility::from_generic(tcx.sess.default_visibility()));
+-        let llval = llvm::LLVMConstInt(i8, 0, False);
+-        llvm::set_initializer(ll_g, llval);
++        // __rust_no_alloc_shim_is_unstable_v2
++        create_wrapper_function(
++            tcx,
++            &cx,
++            &mangle_internal_symbol(tcx, NO_ALLOC_SHIM_IS_UNSTABLE),
++            None,
++            &[],
++            None,
++            false,
++        );
+     }
+ 
+     if tcx.sess.opts.debuginfo != DebugInfo::None {
+@@ -99,7 +104,7 @@ fn create_wrapper_function(
+     tcx: TyCtxt<'_>,
+     cx: &SimpleCx<'_>,
+     from_name: &str,
+-    to_name: &str,
++    to_name: Option<&str>,
+     args: &[&Type],
+     output: Option<&Type>,
+     no_return: bool,
+@@ -128,33 +133,38 @@ fn create_wrapper_function(
+         attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[uwtable]);
+     }
+ 
+-    let callee = declare_simple_fn(
+-        &cx,
+-        to_name,
+-        llvm::CallConv::CCallConv,
+-        llvm::UnnamedAddr::Global,
+-        llvm::Visibility::Hidden,
+-        ty,
+-    );
+-    if let Some(no_return) = no_return {
+-        // -> ! DIFlagNoReturn
+-        attributes::apply_to_llfn(callee, llvm::AttributePlace::Function, &[no_return]);
+-    }
+-    llvm::set_visibility(callee, llvm::Visibility::Hidden);
+-
+     let llbb = unsafe { llvm::LLVMAppendBasicBlockInContext(cx.llcx, llfn, c"entry".as_ptr()) };
+-
+     let mut bx = SBuilder::build(&cx, llbb);
+-    let args = args
+-        .iter()
+-        .enumerate()
+-        .map(|(i, _)| llvm::get_param(llfn, i as c_uint))
+-        .collect::<Vec<_>>();
+-    let ret = bx.call(ty, callee, &args, None);
+-    llvm::LLVMSetTailCall(ret, True);
+-    if output.is_some() {
+-        bx.ret(ret);
++
++    if let Some(to_name) = to_name {
++        let callee = declare_simple_fn(
++            &cx,
++            to_name,
++            llvm::CallConv::CCallConv,
++            llvm::UnnamedAddr::Global,
++            llvm::Visibility::Hidden,
++            ty,
++        );
++        if let Some(no_return) = no_return {
++            // -> ! DIFlagNoReturn
++            attributes::apply_to_llfn(callee, llvm::AttributePlace::Function, &[no_return]);
++        }
++        llvm::set_visibility(callee, llvm::Visibility::Hidden);
++
++        let args = args
++            .iter()
++            .enumerate()
++            .map(|(i, _)| llvm::get_param(llfn, i as c_uint))
++            .collect::<Vec<_>>();
++        let ret = bx.call(ty, callee, &args, None);
++        llvm::LLVMSetTailCall(ret, True);
++        if output.is_some() {
++            bx.ret(ret);
++        } else {
++            bx.ret_void()
++        }
+     } else {
++        assert!(output.is_none());
+         bx.ret_void()
+     }
+ }
+diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+index 92b9b6e132e74..d0b6c7470fb9a 100644
+--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
++++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+@@ -219,6 +219,7 @@ fn exported_symbols_provider_local<'tcx>(
+             .chain([
+                 mangle_internal_symbol(tcx, "__rust_alloc_error_handler"),
+                 mangle_internal_symbol(tcx, OomStrategy::SYMBOL),
++                mangle_internal_symbol(tcx, NO_ALLOC_SHIM_IS_UNSTABLE),
+             ])
+         {
+             let exported_symbol = ExportedSymbol::NoDefId(SymbolName::new(tcx, &symbol_name));
+@@ -232,19 +233,6 @@ fn exported_symbols_provider_local<'tcx>(
+                 },
+             ));
+         }
+-
+-        let exported_symbol = ExportedSymbol::NoDefId(SymbolName::new(
+-            tcx,
+-            &mangle_internal_symbol(tcx, NO_ALLOC_SHIM_IS_UNSTABLE),
+-        ));
+-        symbols.push((
+-            exported_symbol,
+-            SymbolExportInfo {
+-                level: SymbolExportLevel::Rust,
+-                kind: SymbolExportKind::Data,
+-                used: false,
+-            },
+-        ))
+     }
+ 
+     if tcx.sess.instrument_coverage() || tcx.sess.opts.cg.profile_generate.enabled() {
+diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs
+index 49a5e20d7cf8b..1db8ad72b321c 100644
+--- a/compiler/rustc_symbol_mangling/src/v0.rs
++++ b/compiler/rustc_symbol_mangling/src/v0.rs
+@@ -85,10 +85,6 @@ pub fn mangle_internal_symbol<'tcx>(tcx: TyCtxt<'tcx>, item_name: &str) -> Strin
+     if item_name == "rust_eh_personality" {
+         // rust_eh_personality must not be renamed as LLVM hard-codes the name
+         return "rust_eh_personality".to_owned();
+-    } else if item_name == "__rust_no_alloc_shim_is_unstable" {
+-        // Temporary back compat hack to give people the chance to migrate to
+-        // include #[rustc_std_internal_symbol].
+-        return "__rust_no_alloc_shim_is_unstable".to_owned();
+     }
+ 
+     let prefix = "_R";
+diff --git a/library/alloc/src/alloc.rs b/library/alloc/src/alloc.rs
+index e1cc4ba25c4ea..b4176e9c1f4d0 100644
+--- a/library/alloc/src/alloc.rs
++++ b/library/alloc/src/alloc.rs
+@@ -31,8 +31,9 @@ unsafe extern "Rust" {
+     #[rustc_std_internal_symbol]
+     fn __rust_alloc_zeroed(size: usize, align: usize) -> *mut u8;
+ 
++    #[rustc_nounwind]
+     #[rustc_std_internal_symbol]
+-    static __rust_no_alloc_shim_is_unstable: u8;
++    fn __rust_no_alloc_shim_is_unstable_v2();
+ }
+ 
+ /// The global memory allocator.
+@@ -88,7 +89,7 @@ pub unsafe fn alloc(layout: Layout) -> *mut u8 {
+     unsafe {
+         // Make sure we don't accidentally allow omitting the allocator shim in
+         // stable code until it is actually stabilized.
+-        core::ptr::read_volatile(&__rust_no_alloc_shim_is_unstable);
++        __rust_no_alloc_shim_is_unstable_v2();
+ 
+         __rust_alloc(layout.size(), layout.align())
+     }
+@@ -171,7 +172,7 @@ pub unsafe fn alloc_zeroed(layout: Layout) -> *mut u8 {
+     unsafe {
+         // Make sure we don't accidentally allow omitting the allocator shim in
+         // stable code until it is actually stabilized.
+-        core::ptr::read_volatile(&__rust_no_alloc_shim_is_unstable);
++        __rust_no_alloc_shim_is_unstable_v2();
+ 
+         __rust_alloc_zeroed(layout.size(), layout.align())
+     }
+diff --git a/src/tools/miri/src/shims/extern_static.rs b/src/tools/miri/src/shims/extern_static.rs
+index 2feed5a835228..a2ea3dbd88b11 100644
+--- a/src/tools/miri/src/shims/extern_static.rs
++++ b/src/tools/miri/src/shims/extern_static.rs
+@@ -45,10 +45,6 @@ impl<'tcx> MiriMachine<'tcx> {
+ 
+     /// Sets up the "extern statics" for this machine.
+     pub fn init_extern_statics(ecx: &mut MiriInterpCx<'tcx>) -> InterpResult<'tcx> {
+-        // "__rust_no_alloc_shim_is_unstable"
+-        let val = ImmTy::from_int(0, ecx.machine.layouts.u8); // always 0, value does not matter
+-        Self::alloc_extern_static(ecx, "__rust_no_alloc_shim_is_unstable", val)?;
+-
+         // "__rust_alloc_error_handler_should_panic"
+         let val = ecx.tcx.sess.opts.unstable_opts.oom.should_panic();
+         let val = ImmTy::from_int(val, ecx.machine.layouts.u8);
+diff --git a/src/tools/miri/src/shims/foreign_items.rs b/src/tools/miri/src/shims/foreign_items.rs
+index 39b930fdeb92d..416cb1ab55e6a 100644
+--- a/src/tools/miri/src/shims/foreign_items.rs
++++ b/src/tools/miri/src/shims/foreign_items.rs
+@@ -611,6 +611,10 @@ trait EvalContextExtPriv<'tcx>: crate::MiriInterpCxExt<'tcx> {
+                     this.write_pointer(new_ptr, dest)
+                 });
+             }
++            name if name == this.mangle_internal_symbol("__rust_no_alloc_shim_is_unstable_v2") => {
++                // This is a no-op shim that only exists to prevent making the allocator shims instantly stable.
++                let [] = this.check_shim(abi, CanonAbi::Rust, link_name, args)?;
++            }
+ 
+             // C memory handling functions
+             "memcmp" => {
+diff --git a/tests/codegen/alloc-optimisation.rs b/tests/codegen/alloc-optimisation.rs
+index 19f14647c1d7d..3735860d510fb 100644
+--- a/tests/codegen/alloc-optimisation.rs
++++ b/tests/codegen/alloc-optimisation.rs
+@@ -5,7 +5,8 @@
+ pub fn alloc_test(data: u32) {
+     // CHECK-LABEL: @alloc_test
+     // CHECK-NEXT: start:
+-    // CHECK-NEXT: {{.*}} load volatile i8, ptr @{{.*}}__rust_no_alloc_shim_is_unstable, align 1
++    // CHECK-NEXT: ; call __rustc::__rust_no_alloc_shim_is_unstable_v2
++    // CHECK-NEXT: tail call void @_R{{.+}}__rust_no_alloc_shim_is_unstable_v2()
+     // CHECK-NEXT: ret void
+     let x = Box::new(data);
+     drop(x);
+diff --git a/tests/codegen/unwind-landingpad-inline.rs b/tests/codegen/unwind-landingpad-inline.rs
+index 920774b340240..1cf606279e623 100644
+--- a/tests/codegen/unwind-landingpad-inline.rs
++++ b/tests/codegen/unwind-landingpad-inline.rs
+@@ -10,8 +10,10 @@
+ // See https://github.com/rust-lang/rust/issues/46515
+ // CHECK-LABEL: @check_no_escape_in_landingpad
+ // CHECK: start:
+-// CHECK-NEXT: __rust_no_alloc_shim_is_unstable
+-// CHECK-NEXT: __rust_no_alloc_shim_is_unstable
++// CHECK-NEXT: ; call __rustc::__rust_no_alloc_shim_is_unstable_v2
++// CHECK-NEXT: tail call void @[[NO_ALLOC_SHIM:_R.+__rust_no_alloc_shim_is_unstable_v2]]()
++// CHECK-NEXT: ; call __rustc::__rust_no_alloc_shim_is_unstable_v2
++// CHECK-NEXT: tail call void @[[NO_ALLOC_SHIM]]()
+ // CHECK-NEXT: ret void
+ #[no_mangle]
+ pub fn check_no_escape_in_landingpad(f: fn()) {
+diff --git a/tests/codegen/vec-iter-collect-len.rs b/tests/codegen/vec-iter-collect-len.rs
+index a88573522d4d8..807548ef883f5 100644
+--- a/tests/codegen/vec-iter-collect-len.rs
++++ b/tests/codegen/vec-iter-collect-len.rs
+@@ -4,7 +4,9 @@
+ #[no_mangle]
+ pub fn get_len() -> usize {
+     // CHECK-LABEL: @get_len
+-    // CHECK-NOT: call
+-    // CHECK-NOT: invoke
++    // CHECK-NEXT: start:
++    // CHECK-NEXT: ; call __rustc::__rust_no_alloc_shim_is_unstable_v2
++    // CHECK-NEXT: tail call void @_R{{.+}}__rust_no_alloc_shim_is_unstable_v2()
++    // CHECK-NEXT: ret i{{[0-9]+}} 3
+     [1, 2, 3].iter().collect::<Vec<_>>().len()
+ }
+diff --git a/tests/codegen/vec-optimizes-away.rs b/tests/codegen/vec-optimizes-away.rs
+index f6ed2898bdaaa..93b55454b108c 100644
+--- a/tests/codegen/vec-optimizes-away.rs
++++ b/tests/codegen/vec-optimizes-away.rs
+@@ -5,7 +5,8 @@
+ pub fn sum_me() -> i32 {
+     // CHECK-LABEL: @sum_me
+     // CHECK-NEXT: {{^.*:$}}
+-    // CHECK-NEXT: {{.*}} load volatile i8, ptr @{{.*}}__rust_no_alloc_shim_is_unstable, align 1
++    // CHECK-NEXT: ; call __rustc::__rust_no_alloc_shim_is_unstable_v2
++    // CHECK-NEXT: tail call void @_R{{.+}}__rust_no_alloc_shim_is_unstable_v2()
+     // CHECK-NEXT: ret i32 6
+     vec![1, 2, 3].iter().sum::<i32>()
+ }
+diff --git a/tests/run-make/no-alloc-shim/foo.rs b/tests/run-make/no-alloc-shim/foo.rs
+index 42606961f8bb2..b5d0d394d2b9f 100644
+--- a/tests/run-make/no-alloc-shim/foo.rs
++++ b/tests/run-make/no-alloc-shim/foo.rs
+@@ -1,4 +1,4 @@
+-#![feature(default_alloc_error_handler)]
++#![feature(rustc_attrs)]
+ #![no_std]
+ #![no_main]
+ 
+@@ -31,8 +31,8 @@ unsafe impl GlobalAlloc for Alloc {
+ }
+ 
+ #[cfg(not(check_feature_gate))]
+-#[no_mangle]
+-static __rust_no_alloc_shim_is_unstable: u8 = 0;
++#[rustc_std_internal_symbol]
++fn __rust_no_alloc_shim_is_unstable_v2() {}
+ 
+ #[no_mangle]
+ extern "C" fn main(_argc: core::ffi::c_int, _argv: *const *const i8) -> i32 {
+diff --git a/tests/run-make/no-alloc-shim/rmake.rs b/tests/run-make/no-alloc-shim/rmake.rs
+index d61ef5de8c56c..47cabfc208c77 100644
+--- a/tests/run-make/no-alloc-shim/rmake.rs
++++ b/tests/run-make/no-alloc-shim/rmake.rs
+@@ -7,12 +7,6 @@
+ //@ ignore-cross-compile
+ // Reason: the compiled binary is executed
+ 
+-//@ ignore-msvc
+-//FIXME(Oneirical): Getting this to work on MSVC requires passing libcmt.lib to CC,
+-// which is not trivial to do.
+-// Tracking issue: https://github.com/rust-lang/rust/issues/128602
+-// Discussion: https://github.com/rust-lang/rust/pull/128407#discussion_r1702439172
+-
+ use run_make_support::{cc, has_extension, has_prefix, run, rustc, shallow_find_files};
+ 
+ fn main() {
+@@ -30,15 +24,28 @@ fn main() {
+         has_prefix(path, "libcompiler_builtins") && has_extension(path, "rlib")
+     });
+ 
++    #[allow(unused_mut)]
++    let mut platform_args = Vec::<String>::new();
++    #[cfg(target_env = "msvc")]
++    {
++        platform_args.push("-MD".to_string());
++
++        // `/link` tells MSVC that the remaining arguments are linker options.
++        platform_args.push("/link".to_string());
++        platform_args.push("vcruntime.lib".to_string());
++        platform_args.push("msvcrt.lib".to_string());
++    }
++
+     cc().input("foo.o")
+         .out_exe("foo")
++        .args(&platform_args)
+         .args(&alloc_libs)
+         .args(&core_libs)
+         .args(&compiler_builtins_libs)
+         .run();
+     run("foo");
+ 
+-    // Check that linking without __rust_no_alloc_shim_is_unstable defined fails
++    // Check that linking without __rust_no_alloc_shim_is_unstable_v2 defined fails
+     rustc()
+         .input("foo.rs")
+         .crate_type("bin")
+@@ -48,6 +55,7 @@ fn main() {
+         .run();
+     cc().input("foo.o")
+         .out_exe("foo")
++        .args(&platform_args)
+         .args(&alloc_libs)
+         .args(&core_libs)
+         .args(&compiler_builtins_libs)
+diff --git a/tests/run-make/symbols-all-mangled/rmake.rs b/tests/run-make/symbols-all-mangled/rmake.rs
+index 79ddd06bb94be..2cf579758002a 100644
+--- a/tests/run-make/symbols-all-mangled/rmake.rs
++++ b/tests/run-make/symbols-all-mangled/rmake.rs
+@@ -35,10 +35,6 @@ fn symbols_check_archive(path: &str) {
+             continue; // All compiler-builtins symbols must remain unmangled
+         }
+ 
+-        if name == "__rust_no_alloc_shim_is_unstable" {
+-            continue; // FIXME remove exception once we mangle this symbol
+-        }
+-
+         if name.contains("rust_eh_personality") {
+             continue; // Unfortunately LLVM doesn't allow us to mangle this symbol
+         }
+@@ -75,10 +71,6 @@ fn symbols_check(path: &str) {
+             continue;
+         }
+ 
+-        if name == "__rust_no_alloc_shim_is_unstable" {
+-            continue; // FIXME remove exception once we mangle this symbol
+-        }
+-
+         if name.contains("rust_eh_personality") {
+             continue; // Unfortunately LLVM doesn't allow us to mangle this symbol
+         }
+diff --git a/tests/ui/sanitizer/dataflow-abilist.txt b/tests/ui/sanitizer/dataflow-abilist.txt
+index fe04838f5493e..3d32397a175d4 100644
+--- a/tests/ui/sanitizer/dataflow-abilist.txt
++++ b/tests/ui/sanitizer/dataflow-abilist.txt
+@@ -503,3 +503,4 @@ fun:__rust_realloc=uninstrumented
+ fun:_ZN4core*=uninstrumented
+ fun:_ZN3std*=uninstrumented
+ fun:rust_eh_personality=uninstrumented
++fun:_R*__rustc*=uninstrumented