Stabilize extended_varargs_abi_support

Author: Soveu

compiler/rustc_feature/src/accepted.rs

@@ -159,6 +159,9 @@ declare_features! (
     (accepted, explicit_generic_args_with_impl_trait, "1.63.0", Some(83701), None),
     /// Allows arbitrary expressions in key-value attributes at parse time.
     (accepted, extended_key_value_attributes, "1.54.0", Some(78835), None),
+    /// Allows using `efiapi`, `aapcs`, `sysv64` and `win64` as calling
+    /// convention for functions with varargs.
+    (accepted, extended_varargs_abi_support, "1.74.0", Some(100189), None),
     /// Allows resolving absolute paths as paths from other crates.
     (accepted, extern_absolute_paths, "1.30.0", Some(44660), None),
     /// Allows `extern crate foo as bar;`. This puts `bar` into extern prelude.

compiler/rustc_feature/src/unstable.rs

@@ -443,9 +443,6 @@ declare_features! (
     (unstable, exhaustive_patterns, "1.13.0", Some(51085), None),
     /// Allows explicit tail calls via `become` expression.
     (incomplete, explicit_tail_calls, "1.72.0", Some(112788), None),
-    /// Allows using `efiapi`, `sysv64` and `win64` as calling convention
-    /// for functions with varargs.
-    (unstable, extended_varargs_abi_support, "1.65.0", Some(100189), None),
     /// Allows defining `extern type`s.
     (unstable, extern_types, "1.23.0", Some(43467), None),
     /// Allows the use of `#[ffi_const]` on foreign functions.

compiler/rustc_hir_analysis/messages.ftl

@@ -408,7 +408,7 @@ hir_analysis_value_of_associated_struct_already_specified =
     .label = re-bound here
     .previous_bound_label = `{$item_name}` bound here first
 
-hir_analysis_variadic_function_compatible_convention = C-variadic function must have a compatible calling convention, like {$conventions}
+hir_analysis_variadic_function_compatible_convention = C-variadic function must have a compatible calling convention, like `C`, `cdecl`, `aapcs`, `win64`, `sysv64` or `efiapi`
     .label = C-variadic function must have a compatible calling convention
 
 hir_analysis_variances_of = {$variances_of}

compiler/rustc_hir_analysis/src/errors.rs

@@ -424,11 +424,10 @@ pub(crate) struct MainFunctionGenericParameters {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_variadic_function_compatible_convention, code = "E0045")]
-pub(crate) struct VariadicFunctionCompatibleConvention<'a> {
+pub(crate) struct VariadicFunctionCompatibleConvention {
     #[primary_span]
     #[label]
     pub span: Span,
-    pub conventions: &'a str,
 }
 
 #[derive(Diagnostic)]

compiler/rustc_hir_analysis/src/lib.rs

@@ -106,8 +106,7 @@ use rustc_middle::middle;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::util;
-use rustc_session::parse::feature_err;
-use rustc_span::{symbol::sym, Span, DUMMY_SP};
+use rustc_span::{Span, DUMMY_SP};
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits;
 
@@ -118,38 +117,9 @@ use rustc_hir::def::DefKind;
 fluent_messages! { "../messages.ftl" }
 
 fn require_c_abi_if_c_variadic(tcx: TyCtxt<'_>, decl: &hir::FnDecl<'_>, abi: Abi, span: Span) {
-    const CONVENTIONS_UNSTABLE: &str = "`C`, `cdecl`, `aapcs`, `win64`, `sysv64` or `efiapi`";
-    const CONVENTIONS_STABLE: &str = "`C` or `cdecl`";
-    const UNSTABLE_EXPLAIN: &str =
-        "using calling conventions other than `C` or `cdecl` for varargs functions is unstable";
-
-    if !decl.c_variadic || matches!(abi, Abi::C { .. } | Abi::Cdecl { .. }) {
-        return;
+    if decl.c_variadic && !abi.supports_varargs() {
+        tcx.sess.emit_err(errors::VariadicFunctionCompatibleConvention { span });
     }
-
-    let extended_abi_support = tcx.features().extended_varargs_abi_support;
-    let conventions = match (extended_abi_support, abi.supports_varargs()) {
-        // User enabled additional ABI support for varargs and function ABI matches those ones.
-        (true, true) => return,
-
-        // Using this ABI would be ok, if the feature for additional ABI support was enabled.
-        // Return CONVENTIONS_STABLE, because we want the other error to look the same.
-        (false, true) => {
-            feature_err(
-                &tcx.sess.parse_sess,
-                sym::extended_varargs_abi_support,
-                span,
-                UNSTABLE_EXPLAIN,
-            )
-            .emit();
-            CONVENTIONS_STABLE
-        }
-
-        (false, false) => CONVENTIONS_STABLE,
-        (true, false) => CONVENTIONS_UNSTABLE,
-    };
-
-    tcx.sess.emit_err(errors::VariadicFunctionCompatibleConvention { span, conventions });
 }
 
 pub fn provide(providers: &mut Providers) {

src/doc/unstable-book/src/language-features/extended-varargs-abi-support.md

@@ -1,4 +1,4 @@
-error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
+error[E0045]: C-variadic function must have a compatible calling convention, like `C`, `cdecl`, `aapcs`, `win64`, `sysv64` or `efiapi`
   --> $DIR/variadic-ffi-1.rs:9:5
    |
 LL |     fn printf(_: *const u8, ...);

tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.rs

@@ -1,5 +1,4 @@
 // ignore-arm stdcall isn't supported
-#![feature(extended_varargs_abi_support)]
 
 fn baz(f: extern "stdcall" fn(usize, ...)) {
     //~^ ERROR: C-variadic function must have a compatible calling convention,