Rollup merge of #127766 - folkertdev:c-cmse-nonsecure-entry, r=jackh726

add `extern "C-cmse-nonsecure-entry" fn`

tracking issue #75835

in https://github.com/rust-lang/rust/issues/75835#issuecomment-1183517255 it was decided that using an abi, rather than an attribute, was the right way to go for this feature.

This PR adds that ABI and removes the `#[cmse_nonsecure_entry]` attribute. All relevant tests have been updated, some are now obsolete and have been removed.

Error 0775 is no longer generated. It contains the list of targets that support the CMSE feature, and maybe we want to still use this? right now a generic "this abi is not supported on this platform" error is returned when this abi is used on an unsupported platform. On the other hand, users of this abi are likely to be experienced rust users, so maybe the generic error is good enough.

5 files changed, 9 insertions, 5 deletions

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
index 338fbc4b2bf..ca95ccf33ac 100644
--- a/src/doc/unstable-book/src/language-features/cmse-nonsecure-entry.md
+++ b/src/doc/unstable-book/src/language-features/cmse-nonsecure-entry.md
@@ -15,10 +15,10 @@ LLVM, the Rust compiler and the linker are providing
 TrustZone-M feature.
 
 One of the things provided, with this unstable feature, is the
-`cmse_nonsecure_entry` attribute.  This attribute marks a Secure function as an
+`C-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 attribute, the compiler will do the following:
+With this ABI, the compiler will do the following:
 * add a special symbol on the function which is the `__acle_se_` prefix and the
   standard function name
 * constrain the number of parameters to avoid using the Non-Secure stack
@@ -38,11 +38,11 @@ gateway veneer.
 <!-- NOTE(ignore) this example is specific to thumbv8m targets -->
 
 ``` rust,ignore
+#![no_std]
 #![feature(cmse_nonsecure_entry)]
 
 #[no_mangle]
-#[cmse_nonsecure_entry]
-pub extern "C" fn entry_function(input: u32) -> u32 {
+pub extern "C-cmse-nonsecure-entry" fn entry_function(input: u32) -> u32 {
     input + 6
 }
 ```
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs b/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs
index 2f4e764f4ce..26ab02558a1 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs
@@ -377,6 +377,7 @@ pub enum FnAbi {
     AvrNonBlockingInterrupt,
     C,
     CCmseNonsecureCall,
+    CCmseNonsecureEntry,
     CDecl,
     CDeclUnwind,
     CUnwind,
@@ -434,6 +435,7 @@ impl FnAbi {
             s if *s == sym::avr_dash_interrupt => FnAbi::AvrInterrupt,
             s if *s == sym::avr_dash_non_dash_blocking_dash_interrupt => FnAbi::AvrNonBlockingInterrupt,
             s if *s == sym::C_dash_cmse_dash_nonsecure_dash_call => FnAbi::CCmseNonsecureCall,
+            s if *s == sym::C_dash_cmse_dash_nonsecure_dash_entry => FnAbi::CCmseNonsecureEntry,
             s if *s == sym::C_dash_unwind => FnAbi::CUnwind,
             s if *s == sym::C => FnAbi::C,
             s if *s == sym::cdecl_dash_unwind => FnAbi::CDeclUnwind,
@@ -477,6 +479,7 @@ impl FnAbi {
             FnAbi::AvrNonBlockingInterrupt => "avr-non-blocking-interrupt",
             FnAbi::C => "C",
             FnAbi::CCmseNonsecureCall => "C-cmse-nonsecure-call",
+            FnAbi::CCmseNonsecureEntry => "C-cmse-nonsecure-entry",
             FnAbi::CDecl => "C-decl",
             FnAbi::CDeclUnwind => "cdecl-unwind",
             FnAbi::CUnwind => "C-unwind",
diff --git a/src/tools/rust-analyzer/crates/ide-completion/src/completions/extern_abi.rs b/src/tools/rust-analyzer/crates/ide-completion/src/completions/extern_abi.rs
index 1a06e0a3a0e..b0e417e6b33 100644
--- a/src/tools/rust-analyzer/crates/ide-completion/src/completions/extern_abi.rs
+++ b/src/tools/rust-analyzer/crates/ide-completion/src/completions/extern_abi.rs
@@ -32,6 +32,7 @@ const SUPPORTED_CALLING_CONVENTIONS: &[&str] = &[
     "riscv-interrupt-m",
     "riscv-interrupt-s",
     "C-cmse-nonsecure-call",
+    "C-cmse-nonsecure-entry",
     "wasm",
     "system",
     "system-unwind",
diff --git a/src/tools/rust-analyzer/crates/intern/src/symbol/symbols.rs b/src/tools/rust-analyzer/crates/intern/src/symbol/symbols.rs
index 7eb8e4a5e2e..c066f504891 100644
--- a/src/tools/rust-analyzer/crates/intern/src/symbol/symbols.rs
+++ b/src/tools/rust-analyzer/crates/intern/src/symbol/symbols.rs
@@ -94,6 +94,7 @@ define_symbols! {
     avr_dash_interrupt = "avr-interrupt",
     avr_dash_non_dash_blocking_dash_interrupt = "avr-non-blocking-interrupt",
     C_dash_cmse_dash_nonsecure_dash_call = "C-cmse-nonsecure-call",
+    C_dash_cmse_dash_nonsecure_dash_entry = "C-cmse-nonsecure-entry",
     C_dash_unwind = "C-unwind",
     cdecl_dash_unwind = "cdecl-unwind",
     fastcall_dash_unwind = "fastcall-unwind",
diff --git a/src/tools/tidy/src/issues.txt b/src/tools/tidy/src/issues.txt
index 427ed9116d3..3879f350e94 100644
--- a/src/tools/tidy/src/issues.txt
+++ b/src/tools/tidy/src/issues.txt
@@ -467,7 +467,6 @@ ui/closures/issue-87814-2.rs
 ui/closures/issue-90871.rs
 ui/closures/issue-97607.rs
 ui/closures/issue-99565.rs
-ui/cmse-nonsecure/cmse-nonsecure-entry/issue-83475.rs
 ui/codegen/auxiliary/issue-97708-aux.rs
 ui/codegen/issue-101585-128bit-repeat.rs
 ui/codegen/issue-16602-1.rs