rust-lang · workingjubilee · Jun 7, 2025 · Jun 7, 2025 · Jun 7, 2025 · Jun 7, 2025
diff --git a/compiler/rustc_abi/src/canon_abi.rs b/compiler/rustc_abi/src/canon_abi.rs
@@ -59,8 +59,8 @@ impl fmt::Display for CanonAbi {
             CanonAbi::RustCold => ExternAbi::RustCold,
             CanonAbi::Arm(arm_call) => match arm_call {
                 ArmCall::Aapcs => ExternAbi::Aapcs { unwind: false },
-                ArmCall::CCmseNonSecureCall => ExternAbi::CCmseNonSecureCall,
-                ArmCall::CCmseNonSecureEntry => ExternAbi::CCmseNonSecureEntry,
+                ArmCall::CCmseNonSecureCall => ExternAbi::CmseNonSecureCall,
+                ArmCall::CCmseNonSecureEntry => ExternAbi::CmseNonSecureEntry,
             },
             CanonAbi::GpuKernel => ExternAbi::GpuKernel,
             CanonAbi::Interrupt(interrupt_kind) => match interrupt_kind {

diff --git a/compiler/rustc_abi/src/extern_abi.rs b/compiler/rustc_abi/src/extern_abi.rs
@@ -50,9 +50,9 @@ pub enum ExternAbi {
         unwind: bool,
     },
     /// extremely constrained barely-C ABI for TrustZone
-    CCmseNonSecureCall,
+    CmseNonSecureCall,
     /// extremely constrained barely-C ABI for TrustZone
-    CCmseNonSecureEntry,
+    CmseNonSecureEntry,
 
     /* gpu */
     /// An entry-point function called by the GPU's host
@@ -131,8 +131,6 @@ macro_rules! abi_impls {
 abi_impls! {
     ExternAbi = {
             C { unwind: false } =><= "C",
-            CCmseNonSecureCall =><= "C-cmse-nonsecure-call",
-            CCmseNonSecureEntry =><= "C-cmse-nonsecure-entry",
             C { unwind: true } =><= "C-unwind",
             Rust =><= "Rust",
             Aapcs { unwind: false } =><= "aapcs",
@@ -141,6 +139,8 @@ abi_impls! {
             AvrNonBlockingInterrupt =><= "avr-non-blocking-interrupt",
             Cdecl { unwind: false } =><= "cdecl",
             Cdecl { unwind: true } =><= "cdecl-unwind",
+            CmseNonSecureCall =><= "cmse-nonsecure-call",
+            CmseNonSecureEntry =><= "cmse-nonsecure-entry",
             EfiApi =><= "efiapi",
             Fastcall { unwind: false } =><= "fastcall",
             Fastcall { unwind: true } =><= "fastcall-unwind",

diff --git a/compiler/rustc_ast_lowering/src/stability.rs b/compiler/rustc_ast_lowering/src/stability.rs
@@ -124,12 +124,12 @@ pub fn extern_abi_stability(abi: ExternAbi) -> Result<(), UnstableAbi> {
             feature: sym::abi_riscv_interrupt,
             explain: GateReason::Experimental,
         }),
-        ExternAbi::CCmseNonSecureCall => Err(UnstableAbi {
+        ExternAbi::CmseNonSecureCall => Err(UnstableAbi {
             abi,
             feature: sym::abi_c_cmse_nonsecure_call,
             explain: GateReason::Experimental,
         }),
-        ExternAbi::CCmseNonSecureEntry => Err(UnstableAbi {
+        ExternAbi::CmseNonSecureEntry => Err(UnstableAbi {
             abi,
             feature: sym::cmse_nonsecure_entry,
             explain: GateReason::Experimental,

diff --git a/compiler/rustc_error_codes/src/error_codes/E0775.md b/compiler/rustc_error_codes/src/error_codes/E0775.md
@@ -8,7 +8,7 @@ Erroneous code example:
 ```ignore (no longer emitted)
 #![feature(cmse_nonsecure_entry)]
 
-pub extern "C-cmse-nonsecure-entry" fn entry_function() {}
+pub extern "cmse-nonsecure-entry" fn entry_function() {}
 ```
 
 To fix this error, compile your code for a Rust target that supports the

diff --git a/compiler/rustc_error_codes/src/error_codes/E0781.md b/compiler/rustc_error_codes/src/error_codes/E0781.md
@@ -1,12 +1,12 @@
-The `C-cmse-nonsecure-call` ABI can only be used with function pointers.
+The `cmse-nonsecure-call` ABI can only be used with function pointers.
 
 Erroneous code example:
 
 ```compile_fail,E0781
 #![feature(abi_c_cmse_nonsecure_call)]
 
-pub extern "C-cmse-nonsecure-call" fn test() {}
+pub extern "cmse-nonsecure-call" fn test() {}
 ```
 
-The `C-cmse-nonsecure-call` ABI should be used by casting function pointers to
+The `cmse-nonsecure-call` ABI should be used by casting function pointers to
 specific addresses.
diff --git a/compiler/rustc_error_codes/src/error_codes/E0798.md b/compiler/rustc_error_codes/src/error_codes/E0798.md
@@ -1,4 +1,4 @@
-Functions marked as `C-cmse-nonsecure-call` place restrictions on their
+Functions marked as `cmse-nonsecure-call` place restrictions on their
 inputs and outputs.
 
 - inputs must fit in the 4 available 32-bit argument registers. Alignment
@@ -17,7 +17,7 @@ Erroneous code example:
 
 #[no_mangle]
 pub fn test(
-    f: extern "C-cmse-nonsecure-call" fn(u32, u32, u32, u32, u32) -> u32,
+    f: extern "cmse-nonsecure-call" fn(u32, u32, u32, u32, u32) -> u32,
 ) -> u32 {
     f(1, 2, 3, 4, 5)
 }
@@ -32,7 +32,7 @@ room left for the final `f32` argument
 
 #[no_mangle]
 pub fn test(
-    f: extern "C-cmse-nonsecure-call" fn(u32, u64, f32) -> u32,
+    f: extern "cmse-nonsecure-call" fn(u32, u64, f32) -> u32,
 ) -> u32 {
     f(1, 2, 3.0)
 }

diff --git a/compiler/rustc_error_codes/src/lib.rs b/compiler/rustc_error_codes/src/lib.rs
@@ -688,5 +688,5 @@ E0804: 0804,
 //  E0723, // unstable feature in `const` context
 //  E0738, // Removed; errored on `#[track_caller] fn`s in `extern "Rust" { ... }`.
 //  E0744, // merged into E0728
-//  E0776, // Removed; cmse_nonsecure_entry is now `C-cmse-nonsecure-entry`
+//  E0776, // Removed; `#[cmse_nonsecure_entry]` is now `extern "cmse-nonsecure-entry"`
 //  E0796, // unused error code. We use `static_mut_refs` lint instead.
diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
@@ -351,7 +351,7 @@ declare_features! (
 
     /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`.
     (unstable, abi_avr_interrupt, "1.45.0", Some(69664)),
-    /// Allows `extern "C-cmse-nonsecure-call" fn()`.
+    /// Allows `extern "cmse-nonsecure-call" fn()`.
     (unstable, abi_c_cmse_nonsecure_call, "1.51.0", Some(81391)),
     /// Allows `extern "gpu-kernel" fn()`.
     (unstable, abi_gpu_kernel, "1.86.0", Some(135467)),
@@ -427,7 +427,7 @@ declare_features! (
     (unstable, closure_lifetime_binder, "1.64.0", Some(97362)),
     /// Allows `#[track_caller]` on closures and coroutines.
     (unstable, closure_track_caller, "1.57.0", Some(87417)),
-    /// Allows `extern "C-cmse-nonsecure-entry" fn()`.
+    /// Allows `extern "cmse-nonsecure-entry" fn()`.
     (unstable, cmse_nonsecure_entry, "1.48.0", Some(75835)),
     /// Allows `async {}` expressions in const contexts.
     (unstable, const_async_blocks, "1.53.0", Some(85368)),

diff --git a/compiler/rustc_hir_analysis/messages.ftl b/compiler/rustc_hir_analysis/messages.ftl
@@ -66,10 +66,10 @@ hir_analysis_closure_implicit_hrtb = implicit types in closure signatures are fo
     .label = `for<...>` is here
 
 hir_analysis_cmse_call_generic =
-    function pointers with the `"C-cmse-nonsecure-call"` ABI cannot contain generics in their type
+    function pointers with the `"cmse-nonsecure-call"` ABI cannot contain generics in their type
 
 hir_analysis_cmse_entry_generic =
-    functions with the `"C-cmse-nonsecure-entry"` ABI cannot contain generics in their type
+    functions with the `"cmse-nonsecure-entry"` ABI cannot contain generics in their type
 
 hir_analysis_cmse_inputs_stack_spill =
     arguments for `{$abi}` function too large to pass via registers

diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/cmse.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/cmse.rs
@@ -18,7 +18,7 @@ pub(crate) fn validate_cmse_abi<'tcx>(
     fn_sig: ty::PolyFnSig<'tcx>,
 ) {
     match abi {
-        ExternAbi::CCmseNonSecureCall => {
+        ExternAbi::CmseNonSecureCall => {
             let hir_node = tcx.hir_node(hir_id);
             let hir::Node::Ty(hir::Ty {
                 span: bare_fn_span,
@@ -38,7 +38,7 @@ pub(crate) fn validate_cmse_abi<'tcx>(
                     dcx,
                     span,
                     E0781,
-                    "the `\"C-cmse-nonsecure-call\"` ABI is only allowed on function pointers"
+                    "the `\"cmse-nonsecure-call\"` ABI is only allowed on function pointers"
                 )
                 .emit();
                 return;
@@ -78,7 +78,7 @@ pub(crate) fn validate_cmse_abi<'tcx>(
                 }
             };
         }
-        ExternAbi::CCmseNonSecureEntry => {
+        ExternAbi::CmseNonSecureEntry => {
             let hir_node = tcx.hir_node(hir_id);
             let Some(hir::FnSig { decl, span: fn_sig_span, .. }) = hir_node.fn_sig() else {
                 // might happen when this ABI is used incorrectly. That will be handled elsewhere
@@ -203,11 +203,11 @@ fn should_emit_generic_error<'tcx>(abi: ExternAbi, layout_err: &'tcx LayoutError
     match layout_err {
         TooGeneric(ty) => {
             match abi {
-                ExternAbi::CCmseNonSecureCall => {
+                ExternAbi::CmseNonSecureCall => {
                     // prevent double reporting of this error
                     !ty.is_impl_trait()
                 }
-                ExternAbi::CCmseNonSecureEntry => true,
+                ExternAbi::CmseNonSecureEntry => true,
                 _ => bug!("invalid ABI: {abi}"),
             }
         }

diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
@@ -1262,10 +1262,10 @@ pub fn fn_can_unwind(tcx: TyCtxt<'_>, fn_def_id: Option<DefId>, abi: ExternAbi)
         | EfiApi
         | AvrInterrupt
         | AvrNonBlockingInterrupt
+        | CmseNonSecureCall
+        | CmseNonSecureEntry
         | RiscvInterruptM
         | RiscvInterruptS
-        | CCmseNonSecureCall
-        | CCmseNonSecureEntry
         | Unadjusted => false,
         Rust | RustCall | RustCold => tcx.sess.panic_strategy() == PanicStrategy::Unwind,
     }

diff --git a/compiler/rustc_smir/src/rustc_internal/internal.rs b/compiler/rustc_smir/src/rustc_internal/internal.rs
@@ -479,6 +479,8 @@ impl RustcInternal for Abi {
             Abi::Vectorcall { unwind } => rustc_abi::ExternAbi::Vectorcall { unwind },
             Abi::Thiscall { unwind } => rustc_abi::ExternAbi::Thiscall { unwind },
             Abi::Aapcs { unwind } => rustc_abi::ExternAbi::Aapcs { unwind },
+            Abi::CCmseNonSecureCall => rustc_abi::ExternAbi::CmseNonSecureCall,
+            Abi::CCmseNonSecureEntry => rustc_abi::ExternAbi::CmseNonSecureEntry,
             Abi::Win64 { unwind } => rustc_abi::ExternAbi::Win64 { unwind },
             Abi::SysV64 { unwind } => rustc_abi::ExternAbi::SysV64 { unwind },
             Abi::PtxKernel => rustc_abi::ExternAbi::PtxKernel,
@@ -488,8 +490,6 @@ impl RustcInternal for Abi {
             Abi::EfiApi => rustc_abi::ExternAbi::EfiApi,
             Abi::AvrInterrupt => rustc_abi::ExternAbi::AvrInterrupt,
             Abi::AvrNonBlockingInterrupt => rustc_abi::ExternAbi::AvrNonBlockingInterrupt,
-            Abi::CCmseNonSecureCall => rustc_abi::ExternAbi::CCmseNonSecureCall,
-            Abi::CCmseNonSecureEntry => rustc_abi::ExternAbi::CCmseNonSecureEntry,
             Abi::System { unwind } => rustc_abi::ExternAbi::System { unwind },
             Abi::RustCall => rustc_abi::ExternAbi::RustCall,
             Abi::Unadjusted => rustc_abi::ExternAbi::Unadjusted,

diff --git a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
@@ -871,8 +871,8 @@ impl<'tcx> Stable<'tcx> for rustc_abi::ExternAbi {
             ExternAbi::EfiApi => Abi::EfiApi,
             ExternAbi::AvrInterrupt => Abi::AvrInterrupt,
             ExternAbi::AvrNonBlockingInterrupt => Abi::AvrNonBlockingInterrupt,
-            ExternAbi::CCmseNonSecureCall => Abi::CCmseNonSecureCall,
-            ExternAbi::CCmseNonSecureEntry => Abi::CCmseNonSecureEntry,
+            ExternAbi::CmseNonSecureCall => Abi::CCmseNonSecureCall,
+            ExternAbi::CmseNonSecureEntry => Abi::CCmseNonSecureEntry,
             ExternAbi::System { unwind } => Abi::System { unwind },
             ExternAbi::RustCall => Abi::RustCall,
             ExternAbi::Unadjusted => Abi::Unadjusted,

diff --git a/compiler/rustc_target/src/spec/abi_map.rs b/compiler/rustc_target/src/spec/abi_map.rs
@@ -84,13 +84,13 @@ impl AbiMap {
             (ExternAbi::Aapcs { .. }, Arch::Arm(..)) => CanonAbi::Arm(ArmCall::Aapcs),
             (ExternAbi::Aapcs { .. }, _) => return AbiMapping::Invalid,
 
-            (ExternAbi::CCmseNonSecureCall, Arch::Arm(ArmVer::ThumbV8M)) => {
+            (ExternAbi::CmseNonSecureCall, Arch::Arm(ArmVer::ThumbV8M)) => {
                 CanonAbi::Arm(ArmCall::CCmseNonSecureCall)
             }
-            (ExternAbi::CCmseNonSecureEntry, Arch::Arm(ArmVer::ThumbV8M)) => {
+            (ExternAbi::CmseNonSecureEntry, Arch::Arm(ArmVer::ThumbV8M)) => {
                 CanonAbi::Arm(ArmCall::CCmseNonSecureEntry)
             }
-            (ExternAbi::CCmseNonSecureCall | ExternAbi::CCmseNonSecureEntry, ..) => {
+            (ExternAbi::CmseNonSecureCall | ExternAbi::CmseNonSecureEntry, ..) => {
                 return AbiMapping::Invalid;
             }
 

diff --git a/src/doc/unstable-book/src/language-features/abi-c-cmse-nonsecure-call.md b/src/doc/unstable-book/src/language-features/abi-c-cmse-nonsecure-call.md
@@ -14,8 +14,8 @@ LLVM, the Rust compiler and the linker are providing
 [support](https://developer.arm.com/documentation/ecm0359818/latest/) for the
 TrustZone-M feature.
 
-One of the things provided, with this unstable feature, is the
-`C-cmse-nonsecure-call` function ABI. This ABI is used on function pointers to
+One of the things provided with this unstable feature is the
+"cmse-nonsecure-call" function ABI. This ABI is used on function pointers to
 non-secure code to mark a non-secure function call (see [section
 5.5](https://developer.arm.com/documentation/ecm0359818/latest/) for details).
 
@@ -28,9 +28,6 @@ With this ABI, the compiler will do the following to perform the call:
 To avoid using the non-secure stack, the compiler will constrain the number and
 type of parameters/return value.
 
-The `extern "C-cmse-nonsecure-call"` ABI is otherwise equivalent to the
-`extern "C"` ABI.
-
 <!-- NOTE(ignore) this example is specific to thumbv8m targets -->
 
 ``` rust,ignore
@@ -40,7 +37,7 @@ The `extern "C-cmse-nonsecure-call"` ABI is otherwise equivalent to the
 #[no_mangle]
 pub fn call_nonsecure_function(addr: usize) -> u32 {
     let non_secure_function =
-        unsafe { core::mem::transmute::<usize, extern "C-cmse-nonsecure-call" fn() -> u32>(addr) };
+        unsafe { core::mem::transmute::<usize, extern "cmse-nonsecure-call" fn() -> u32>(addr) };
     non_secure_function()
 }
 ```

diff --git a/src/doc/unstable-book/src/language-features/cmse-nonsecure-entry.md b/src/doc/unstable-book/src/language-features/cmse-nonsecure-entry.md
@@ -14,8 +14,8 @@ LLVM, the Rust compiler and the linker are providing
 [support](https://developer.arm.com/documentation/ecm0359818/latest/) for the
 TrustZone-M feature.
 
-One of the things provided, with this unstable feature, is the
-`C-cmse-nonsecure-entry` ABI. This ABI marks a Secure function as an
+One of the things provided with this unstable feature is the
+"cmse-nonsecure-entry" ABI. This ABI marks a Secure function as an
 entry function (see [section
 5.4](https://developer.arm.com/documentation/ecm0359818/latest/) for details).
 With this ABI, the compiler will do the following:
@@ -30,7 +30,6 @@ Because the stack can not be used to pass parameters, there will be compilation
 errors if:
 * the total size of all parameters is too big (for example more than four 32
   bits integers)
-* the entry function is not using a C ABI
 
 The special symbol `__acle_se_` will be used by the linker to generate a secure
 gateway veneer.
@@ -42,7 +41,7 @@ gateway veneer.
 #![feature(cmse_nonsecure_entry)]
 
 #[no_mangle]
-pub extern "C-cmse-nonsecure-entry" fn entry_function(input: u32) -> u32 {
+pub extern "cmse-nonsecure-entry" fn entry_function(input: u32) -> u32 {
     input + 6
 }
 ```

diff --git a/tests/assembly/cmse.rs b/tests/assembly/cmse.rs
@@ -53,7 +53,7 @@ use minicore::*;
 // Branch back to non-secure side
 // CHECK: bxns lr
 #[no_mangle]
-pub extern "C-cmse-nonsecure-entry" fn entry_point() -> i64 {
+pub extern "cmse-nonsecure-entry" fn entry_point() -> i64 {
     0
 }
 
@@ -95,8 +95,6 @@ pub extern "C-cmse-nonsecure-entry" fn entry_point() -> i64 {
 // Call to non-secure
 // CHECK: blxns r12
 #[no_mangle]
-pub fn call_nonsecure(
-    f: unsafe extern "C-cmse-nonsecure-call" fn(u32, u32, u32, u32) -> u64,
-) -> u64 {
+pub fn call_nonsecure(f: unsafe extern "cmse-nonsecure-call" fn(u32, u32, u32, u32) -> u64) -> u64 {
     unsafe { f(0, 1, 2, 3) }
 }
diff --git a/tests/crashes/130104.rs b/tests/crashes/130104.rs
@@ -2,5 +2,5 @@
 
 fn main() {
     let non_secure_function =
-        core::mem::transmute::<fn() -> _, extern "C-cmse-nonsecure-call" fn() -> _>;
+        core::mem::transmute::<fn() -> _, extern "cmse-nonsecure-call" fn() -> _>;
 }
diff --git a/tests/crashes/132142.rs b/tests/crashes/132142.rs
@@ -1,3 +1,3 @@
 //@ known-bug: #132142
 
-async extern "C-cmse-nonsecure-entry" fn fun(...) {}
+async extern "cmse-nonsecure-entry" fn fun(...) {}
diff --git a/tests/crashes/132430.rs b/tests/crashes/132430.rs
@@ -6,5 +6,5 @@
 struct Test;
 
 impl Test {
-    pub async unsafe extern "C-cmse-nonsecure-entry" fn test(val: &str) {}
+    pub async unsafe extern "cmse-nonsecure-entry" fn test(val: &str) {}
 }