Rollup of 3 pull requests

compiler/rustc_abi/src/canon_abi.rs

@@ -27,6 +27,7 @@ pub enum CanonAbi {
     C,
     Rust,
     RustCold,
+    RustPreserveNone,
 
     /// An ABI that rustc does not know how to call or define.
     Custom,
@@ -54,7 +55,7 @@ pub enum CanonAbi {
 impl CanonAbi {
     pub fn is_rustic_abi(self) -> bool {
         match self {
-            CanonAbi::Rust | CanonAbi::RustCold => true,
+            CanonAbi::Rust | CanonAbi::RustCold | CanonAbi::RustPreserveNone => true,
             CanonAbi::C
             | CanonAbi::Custom
             | CanonAbi::Arm(_)
@@ -74,6 +75,7 @@ impl fmt::Display for CanonAbi {
             CanonAbi::C => ExternAbi::C { unwind: false },
             CanonAbi::Rust => ExternAbi::Rust,
             CanonAbi::RustCold => ExternAbi::RustCold,
+            CanonAbi::RustPreserveNone => ExternAbi::RustPreserveNone,
             CanonAbi::Custom => ExternAbi::Custom,
             CanonAbi::Arm(arm_call) => match arm_call {
                 ArmCall::Aapcs => ExternAbi::Aapcs { unwind: false },

compiler/rustc_abi/src/extern_abi.rs

@@ -42,6 +42,13 @@ pub enum ExternAbi {
     /// in a platform-agnostic way.
     RustInvalid,
 
+    /// Preserves no registers.
+    ///
+    /// Note, that this ABI is not stable in the registers it uses, is intended as an optimization
+    /// and may fall-back to a more conservative calling convention if the backend does not support
+    /// forcing callers to save all registers.
+    RustPreserveNone,
+
     /// Unstable impl detail that directly uses Rust types to describe the ABI to LLVM.
     /// Even normally-compatible Rust types can become ABI-incompatible with this ABI!
     Unadjusted,
@@ -163,6 +170,7 @@ abi_impls! {
             RustCall =><= "rust-call",
             RustCold =><= "rust-cold",
             RustInvalid =><= "rust-invalid",
+            RustPreserveNone =><= "rust-preserve-none",
             Stdcall { unwind: false } =><= "stdcall",
             Stdcall { unwind: true } =><= "stdcall-unwind",
             System { unwind: false } =><= "system",
@@ -243,7 +251,7 @@ impl ExternAbi {
     /// - are subject to change between compiler versions
     pub fn is_rustic_abi(self) -> bool {
         use ExternAbi::*;
-        matches!(self, Rust | RustCall | RustCold)
+        matches!(self, Rust | RustCall | RustCold | RustPreserveNone)
     }
 
     /// Returns whether the ABI supports C variadics. This only controls whether we allow *imports*
@@ -315,7 +323,8 @@ impl ExternAbi {
             | Self::Thiscall { .. }
             | Self::Vectorcall { .. }
             | Self::SysV64 { .. }
-            | Self::Win64 { .. } => true,
+            | Self::Win64 { .. }
+            | Self::RustPreserveNone => true,
         }
     }
 }

compiler/rustc_ast_lowering/src/stability.rs

@@ -95,6 +95,11 @@ pub fn extern_abi_stability(abi: ExternAbi) -> Result<(), UnstableAbi> {
         ExternAbi::RustCold => {
             Err(UnstableAbi { abi, feature: sym::rust_cold_cc, explain: GateReason::Experimental })
         }
+        ExternAbi::RustPreserveNone => Err(UnstableAbi {
+            abi,
+            feature: sym::rust_preserve_none_cc,
+            explain: GateReason::Experimental,
+        }),
         ExternAbi::RustInvalid => {
             Err(UnstableAbi { abi, feature: sym::rustc_attrs, explain: GateReason::ImplDetail })
         }

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -400,6 +400,7 @@ impl<'a> AstValidator<'a> {
                     CanonAbi::C
                     | CanonAbi::Rust
                     | CanonAbi::RustCold
+                    | CanonAbi::RustPreserveNone
                     | CanonAbi::Arm(_)
                     | CanonAbi::X86(_) => { /* nothing to check */ }
 

compiler/rustc_codegen_cranelift/src/abi/mod.rs

@@ -56,6 +56,9 @@ pub(crate) fn conv_to_call_conv(
         CanonAbi::Rust | CanonAbi::C => default_call_conv,
         CanonAbi::RustCold => CallConv::Cold,
 
+        // Cranelift doesn't currently have anything for this.
+        CanonAbi::RustPreserveNone => default_call_conv,
+
         // Functions with this calling convention can only be called from assembly, but it is
         // possible to declare an `extern "custom"` block, so the backend still needs a calling
         // convention for declaring foreign functions.

compiler/rustc_codegen_gcc/src/abi.rs

@@ -243,6 +243,8 @@ impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
 pub fn conv_to_fn_attribute<'gcc>(conv: CanonAbi, arch: &Arch) -> Option<FnAttribute<'gcc>> {
     let attribute = match conv {
         CanonAbi::C | CanonAbi::Rust => return None,
+        // gcc/gccjit does not have anything for this.
+        CanonAbi::RustPreserveNone => return None,
         CanonAbi::RustCold => FnAttribute::Cold,
         // Functions with this calling convention can only be called from assembly, but it is
         // possible to declare an `extern "custom"` block, so the backend still needs a calling

compiler/rustc_codegen_llvm/src/abi.rs

@@ -694,6 +694,7 @@ pub(crate) fn to_llvm_calling_convention(sess: &Session, abi: CanonAbi) -> llvm:
     match abi {
         CanonAbi::C | CanonAbi::Rust => llvm::CCallConv,
         CanonAbi::RustCold => llvm::PreserveMost,
+        CanonAbi::RustPreserveNone => llvm::PreserveNone,
         // Functions with this calling convention can only be called from assembly, but it is
         // possible to declare an `extern "custom"` block, so the backend still needs a calling
         // convention for declaring foreign functions.

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -370,7 +370,7 @@ fn create_alloc_family_attr(llcx: &llvm::Context) -> &llvm::Attribute {
     llvm::CreateAttrStringValue(llcx, "alloc-family", "__rust_alloc")
 }
 
-/// Helper for `FnAbi::apply_attrs_llfn`:
+/// Helper for `FnAbiLlvmExt::apply_attrs_llfn`:
 /// Composite function which sets LLVM attributes for function depending on its AST (`#[attribute]`)
 /// attributes.
 pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>(

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -167,6 +167,7 @@ pub(crate) enum CallConv {
     PreserveMost = 14,
     PreserveAll = 15,
     Tail = 18,
+    PreserveNone = 21,
     X86StdcallCallConv = 64,
     X86FastcallCallConv = 65,
     ArmAapcsCallConv = 67,

compiler/rustc_expand/src/proc_macro_server.rs

@@ -431,8 +431,6 @@ impl ToInternal<rustc_errors::Level> for Level {
     }
 }
 
-pub(crate) struct FreeFunctions;
-
 pub(crate) struct Rustc<'a, 'b> {
     ecx: &'a mut ExtCtxt<'b>,
     def_site: Span,
@@ -461,13 +459,28 @@ impl<'a, 'b> Rustc<'a, 'b> {
 }
 
 impl server::Types for Rustc<'_, '_> {
-    type FreeFunctions = FreeFunctions;
     type TokenStream = TokenStream;
     type Span = Span;
     type Symbol = Symbol;
 }
 
-impl server::FreeFunctions for Rustc<'_, '_> {
+impl server::Server for Rustc<'_, '_> {
+    fn globals(&mut self) -> ExpnGlobals<Self::Span> {
+        ExpnGlobals {
+            def_site: self.def_site,
+            call_site: self.call_site,
+            mixed_site: self.mixed_site,
+        }
+    }
+
+    fn intern_symbol(string: &str) -> Self::Symbol {
+        Symbol::intern(string)
+    }
+
+    fn with_symbol_string(symbol: &Self::Symbol, f: impl FnOnce(&str)) {
+        f(symbol.as_str())
+    }
+
     fn injected_env_var(&mut self, var: &str) -> Option<String> {
         self.ecx.sess.opts.logical_env.get(var).cloned()
     }
@@ -552,14 +565,20 @@ impl server::FreeFunctions for Rustc<'_, '_> {
         }
         diag.emit();
     }
-}
 
-impl server::TokenStream for Rustc<'_, '_> {
-    fn is_empty(&mut self, stream: &Self::TokenStream) -> bool {
+    fn ts_drop(&mut self, stream: Self::TokenStream) {
+        drop(stream);
+    }
+
+    fn ts_clone(&mut self, stream: &Self::TokenStream) -> Self::TokenStream {
+        stream.clone()
+    }
+
+    fn ts_is_empty(&mut self, stream: &Self::TokenStream) -> bool {
         stream.is_empty()
     }
 
-    fn from_str(&mut self, src: &str) -> Self::TokenStream {
+    fn ts_from_str(&mut self, src: &str) -> Self::TokenStream {
         unwrap_or_emit_fatal(source_str_to_stream(
             self.psess(),
             FileName::proc_macro_source_code(src),
@@ -568,11 +587,11 @@ impl server::TokenStream for Rustc<'_, '_> {
         ))
     }
 
-    fn to_string(&mut self, stream: &Self::TokenStream) -> String {
+    fn ts_to_string(&mut self, stream: &Self::TokenStream) -> String {
         pprust::tts_to_string(stream)
     }
 
-    fn expand_expr(&mut self, stream: &Self::TokenStream) -> Result<Self::TokenStream, ()> {
+    fn ts_expand_expr(&mut self, stream: &Self::TokenStream) -> Result<Self::TokenStream, ()> {
         // Parse the expression from our tokenstream.
         let expr: PResult<'_, _> = try {
             let mut p = Parser::new(self.psess(), stream.clone(), Some("proc_macro expand expr"));
@@ -633,14 +652,14 @@ impl server::TokenStream for Rustc<'_, '_> {
         }
     }
 
-    fn from_token_tree(
+    fn ts_from_token_tree(
         &mut self,
         tree: TokenTree<Self::TokenStream, Self::Span, Self::Symbol>,
     ) -> Self::TokenStream {
         Self::TokenStream::new((tree, &mut *self).to_internal().into_iter().collect::<Vec<_>>())
     }
 
-    fn concat_trees(
+    fn ts_concat_trees(
         &mut self,
         base: Option<Self::TokenStream>,
         trees: Vec<TokenTree<Self::TokenStream, Self::Span, Self::Symbol>>,
@@ -654,7 +673,7 @@ impl server::TokenStream for Rustc<'_, '_> {
         stream
     }
 
-    fn concat_streams(
+    fn ts_concat_streams(
         &mut self,
         base: Option<Self::TokenStream>,
         streams: Vec<Self::TokenStream>,
@@ -666,24 +685,22 @@ impl server::TokenStream for Rustc<'_, '_> {
         stream
     }
 
-    fn into_trees(
+    fn ts_into_trees(
         &mut self,
         stream: Self::TokenStream,
     ) -> Vec<TokenTree<Self::TokenStream, Self::Span, Self::Symbol>> {
         FromInternal::from_internal((stream, self))
     }
-}
 
-impl server::Span for Rustc<'_, '_> {
-    fn debug(&mut self, span: Self::Span) -> String {
+    fn span_debug(&mut self, span: Self::Span) -> String {
         if self.ecx.ecfg.span_debug {
             format!("{span:?}")
         } else {
             format!("{:?} bytes({}..{})", span.ctxt(), span.lo().0, span.hi().0)
         }
     }
 
-    fn file(&mut self, span: Self::Span) -> String {
+    fn span_file(&mut self, span: Self::Span) -> String {
         self.psess()
             .source_map()
             .lookup_char_pos(span.lo())
@@ -693,7 +710,7 @@ impl server::Span for Rustc<'_, '_> {
             .to_string()
     }
 
-    fn local_file(&mut self, span: Self::Span) -> Option<String> {
+    fn span_local_file(&mut self, span: Self::Span) -> Option<String> {
         self.psess()
             .source_map()
             .lookup_char_pos(span.lo())
@@ -708,41 +725,41 @@ impl server::Span for Rustc<'_, '_> {
             })
     }
 
-    fn parent(&mut self, span: Self::Span) -> Option<Self::Span> {
+    fn span_parent(&mut self, span: Self::Span) -> Option<Self::Span> {
         span.parent_callsite()
     }
 
-    fn source(&mut self, span: Self::Span) -> Self::Span {
+    fn span_source(&mut self, span: Self::Span) -> Self::Span {
         span.source_callsite()
     }
 
-    fn byte_range(&mut self, span: Self::Span) -> Range<usize> {
+    fn span_byte_range(&mut self, span: Self::Span) -> Range<usize> {
         let source_map = self.psess().source_map();
 
         let relative_start_pos = source_map.lookup_byte_offset(span.lo()).pos;
         let relative_end_pos = source_map.lookup_byte_offset(span.hi()).pos;
 
         Range { start: relative_start_pos.0 as usize, end: relative_end_pos.0 as usize }
     }
-    fn start(&mut self, span: Self::Span) -> Self::Span {
+    fn span_start(&mut self, span: Self::Span) -> Self::Span {
         span.shrink_to_lo()
     }
 
-    fn end(&mut self, span: Self::Span) -> Self::Span {
+    fn span_end(&mut self, span: Self::Span) -> Self::Span {
         span.shrink_to_hi()
     }
 
-    fn line(&mut self, span: Self::Span) -> usize {
+    fn span_line(&mut self, span: Self::Span) -> usize {
         let loc = self.psess().source_map().lookup_char_pos(span.lo());
         loc.line
     }
 
-    fn column(&mut self, span: Self::Span) -> usize {
+    fn span_column(&mut self, span: Self::Span) -> usize {
         let loc = self.psess().source_map().lookup_char_pos(span.lo());
         loc.col.to_usize() + 1
     }
 
-    fn join(&mut self, first: Self::Span, second: Self::Span) -> Option<Self::Span> {
+    fn span_join(&mut self, first: Self::Span, second: Self::Span) -> Option<Self::Span> {
         let self_loc = self.psess().source_map().lookup_char_pos(first.lo());
         let other_loc = self.psess().source_map().lookup_char_pos(second.lo());
 
@@ -753,7 +770,7 @@ impl server::Span for Rustc<'_, '_> {
         Some(first.to(second))
     }
 
-    fn subspan(
+    fn span_subspan(
         &mut self,
         span: Self::Span,
         start: Bound<usize>,
@@ -789,11 +806,11 @@ impl server::Span for Rustc<'_, '_> {
         Some(span.with_lo(new_lo).with_hi(new_hi))
     }
 
-    fn resolved_at(&mut self, span: Self::Span, at: Self::Span) -> Self::Span {
+    fn span_resolved_at(&mut self, span: Self::Span, at: Self::Span) -> Self::Span {
         span.with_ctxt(at.ctxt())
     }
 
-    fn source_text(&mut self, span: Self::Span) -> Option<String> {
+    fn span_source_text(&mut self, span: Self::Span) -> Option<String> {
         self.psess().source_map().span_to_snippet(span).ok()
     }
 
@@ -821,41 +838,21 @@ impl server::Span for Rustc<'_, '_> {
     /// span from the metadata of `my_proc_macro` (which we have access to,
     /// since we've loaded `my_proc_macro` from disk in order to execute it).
     /// In this way, we have obtained a span pointing into `my_proc_macro`
-    fn save_span(&mut self, span: Self::Span) -> usize {
+    fn span_save_span(&mut self, span: Self::Span) -> usize {
         self.psess().save_proc_macro_span(span)
     }
 
-    fn recover_proc_macro_span(&mut self, id: usize) -> Self::Span {
+    fn span_recover_proc_macro_span(&mut self, id: usize) -> Self::Span {
         let (resolver, krate, def_site) = (&*self.ecx.resolver, self.krate, self.def_site);
         *self.rebased_spans.entry(id).or_insert_with(|| {
             // FIXME: `SyntaxContext` for spans from proc macro crates is lost during encoding,
             // replace it with a def-site context until we are encoding it properly.
             resolver.get_proc_macro_quoted_span(krate, id).with_ctxt(def_site.ctxt())
         })
     }
-}
 
-impl server::Symbol for Rustc<'_, '_> {
-    fn normalize_and_validate_ident(&mut self, string: &str) -> Result<Self::Symbol, ()> {
+    fn symbol_normalize_and_validate_ident(&mut self, string: &str) -> Result<Self::Symbol, ()> {
         let sym = nfc_normalize(string);
         if rustc_lexer::is_ident(sym.as_str()) { Ok(sym) } else { Err(()) }
     }
 }
-
-impl server::Server for Rustc<'_, '_> {
-    fn globals(&mut self) -> ExpnGlobals<Self::Span> {
-        ExpnGlobals {
-            def_site: self.def_site,
-            call_site: self.call_site,
-            mixed_site: self.mixed_site,
-        }
-    }
-
-    fn intern_symbol(string: &str) -> Self::Symbol {
-        Symbol::intern(string)
-    }
-
-    fn with_symbol_string(symbol: &Self::Symbol, f: impl FnOnce(&str)) {
-        f(symbol.as_str())
-    }
-}

compiler/rustc_feature/src/unstable.rs

@@ -632,6 +632,8 @@ declare_features! (
     (unstable, rtm_target_feature, "1.35.0", Some(150258)),
     /// Allows `extern "rust-cold"`.
     (unstable, rust_cold_cc, "1.63.0", Some(97544)),
+    /// Allows `extern "rust-preserve-none"`.
+    (unstable, rust_preserve_none_cc, "CURRENT_RUSTC_VERSION", Some(151401)),
     /// Target features on s390x.
     (unstable, s390x_target_feature, "1.82.0", Some(150259)),
     /// Allows the use of the `sanitize` attribute.