6 files changed, 16 insertions, 45 deletions
diff --git a/compiler/rustc_codegen_gcc/example/arbitrary_self_types_pointers_and_wrappers.rs b/compiler/rustc_codegen_gcc/example/arbitrary_self_types_pointers_and_wrappers.rs
index b299aa87974..c26606f0bdd 100644
--- a/compiler/rustc_codegen_gcc/example/arbitrary_self_types_pointers_and_wrappers.rs
+++ b/compiler/rustc_codegen_gcc/example/arbitrary_self_types_pointers_and_wrappers.rs
@@ -37,10 +37,6 @@ impl<T: DispatchFromDyn<U>, U> DispatchFromDyn<Wrapper<U>> for Wrapper<T> {}
 
 
 trait Trait {
-    // This method isn't object-safe yet. Unsized by-value `self` is object-safe (but not callable
-    // without unsized_locals), but wrappers around `Self` currently are not.
-    // FIXME (mikeyhew) uncomment this when unsized rvalues object-safety is implemented
-    // fn wrapper(self: Wrapper<Self>) -> i32;
     fn ptr_wrapper(self: Ptr<Wrapper<Self>>) -> i32;
     fn wrapper_ptr(self: Wrapper<Ptr<Self>>) -> i32;
     fn wrapper_ptr_wrapper(self: Wrapper<Ptr<Wrapper<Self>>>) -> i32;
diff --git a/compiler/rustc_codegen_gcc/messages.ftl b/compiler/rustc_codegen_gcc/messages.ftl
index 546bfc87b68..18a8a5a1e04 100644
--- a/compiler/rustc_codegen_gcc/messages.ftl
+++ b/compiler/rustc_codegen_gcc/messages.ftl
@@ -2,9 +2,6 @@ codegen_gcc_unknown_ctarget_feature_prefix =
     unknown feature specified for `-Ctarget-feature`: `{$feature}`
     .note = features must begin with a `+` to enable or `-` to disable it
 
-codegen_gcc_forbidden_ctarget_feature =
-    target feature `{$feature}` cannot be toggled with `-Ctarget-feature`: {$reason}
-
 codegen_gcc_unwinding_inline_asm =
     GCC backend does not support unwinding from inline asm
 
@@ -26,10 +23,6 @@ codegen_gcc_unknown_ctarget_feature =
     .possible_feature = you might have meant: `{$rust_feature}`
     .consider_filing_feature_request = consider filing a feature request
 
-codegen_gcc_unstable_ctarget_feature =
-    unstable feature specified for `-Ctarget-feature`: `{$feature}`
-    .note = this feature is not stably supported; its behavior can change in the future
-
 codegen_gcc_missing_features =
     add the missing features in a `target_feature` attribute
 
diff --git a/compiler/rustc_codegen_gcc/src/abi.rs b/compiler/rustc_codegen_gcc/src/abi.rs
index 3d0c258f576..08f3d281904 100644
--- a/compiler/rustc_codegen_gcc/src/abi.rs
+++ b/compiler/rustc_codegen_gcc/src/abi.rs
@@ -239,12 +239,16 @@ impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
 pub fn conv_to_fn_attribute<'gcc>(conv: CanonAbi, arch: &str) -> Option<FnAttribute<'gcc>> {
     let attribute = match conv {
         CanonAbi::C | CanonAbi::Rust => 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
+        // convention for declaring foreign functions.
+        CanonAbi::Custom => return None,
         CanonAbi::Arm(arm_call) => match arm_call {
             ArmCall::CCmseNonSecureCall => FnAttribute::ArmCmseNonsecureCall,
             ArmCall::CCmseNonSecureEntry => FnAttribute::ArmCmseNonsecureEntry,
             ArmCall::Aapcs => FnAttribute::ArmPcs("aapcs"),
         },
-        CanonAbi::RustCold => FnAttribute::Cold,
         CanonAbi::GpuKernel => {
             if arch == "amdgpu" {
                 FnAttribute::GcnAmdGpuHsaKernel
diff --git a/compiler/rustc_codegen_gcc/src/builder.rs b/compiler/rustc_codegen_gcc/src/builder.rs
index d1fb8d8f9d6..1bd89212100 100644
--- a/compiler/rustc_codegen_gcc/src/builder.rs
+++ b/compiler/rustc_codegen_gcc/src/builder.rs
@@ -897,7 +897,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
     fn checked_binop(
         &mut self,
         oop: OverflowOp,
-        typ: Ty<'_>,
+        typ: Ty<'tcx>,
         lhs: Self::Value,
         rhs: Self::Value,
     ) -> (Self::Value, Self::Value) {
diff --git a/compiler/rustc_codegen_gcc/src/errors.rs b/compiler/rustc_codegen_gcc/src/errors.rs
index ccd9abe3804..7786be9ae5d 100644
--- a/compiler/rustc_codegen_gcc/src/errors.rs
+++ b/compiler/rustc_codegen_gcc/src/errors.rs
@@ -17,21 +17,6 @@ pub(crate) struct UnknownCTargetFeature<'a> {
     pub rust_feature: PossibleFeature<'a>,
 }
 
-#[derive(Diagnostic)]
-#[diag(codegen_gcc_unstable_ctarget_feature)]
-#[note]
-pub(crate) struct UnstableCTargetFeature<'a> {
-    pub feature: &'a str,
-}
-
-#[derive(Diagnostic)]
-#[diag(codegen_gcc_forbidden_ctarget_feature)]
-pub(crate) struct ForbiddenCTargetFeature<'a> {
-    pub feature: &'a str,
-    pub enabled: &'a str,
-    pub reason: &'a str,
-}
-
 #[derive(Subdiagnostic)]
 pub(crate) enum PossibleFeature<'a> {
     #[help(codegen_gcc_possible_feature)]
diff --git a/compiler/rustc_codegen_gcc/src/gcc_util.rs b/compiler/rustc_codegen_gcc/src/gcc_util.rs
index 2b053abdd19..d90e66aea31 100644
--- a/compiler/rustc_codegen_gcc/src/gcc_util.rs
+++ b/compiler/rustc_codegen_gcc/src/gcc_util.rs
@@ -5,13 +5,17 @@ use rustc_codegen_ssa::errors::TargetFeatureDisableOrEnable;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::unord::UnordSet;
 use rustc_session::Session;
+use rustc_session::features::{StabilityExt, retpoline_features_by_flags};
 use rustc_target::target_features::RUSTC_SPECIFIC_FEATURES;
 use smallvec::{SmallVec, smallvec};
 
-use crate::errors::{
-    ForbiddenCTargetFeature, PossibleFeature, UnknownCTargetFeature, UnknownCTargetFeaturePrefix,
-    UnstableCTargetFeature,
-};
+use crate::errors::{PossibleFeature, UnknownCTargetFeature, UnknownCTargetFeaturePrefix};
+
+fn gcc_features_by_flags(sess: &Session) -> Vec<&str> {
+    let mut features: Vec<&str> = Vec::new();
+    retpoline_features_by_flags(sess, &mut features);
+    features
+}
 
 /// The list of GCC features computed from CLI flags (`-Ctarget-cpu`, `-Ctarget-feature`,
 /// `--target` and similar).
@@ -45,7 +49,7 @@ pub(crate) fn global_gcc_features(sess: &Session, diagnostics: bool) -> Vec<Stri
 
     // Compute implied features
     let mut all_rust_features = vec![];
-    for feature in sess.opts.cg.target_feature.split(',') {
+    for feature in sess.opts.cg.target_feature.split(',').chain(gcc_features_by_flags(sess)) {
         if let Some(feature) = feature.strip_prefix('+') {
             all_rust_features.extend(
                 UnordSet::from(sess.target.implied_target_features(feature))
@@ -94,18 +98,7 @@ pub(crate) fn global_gcc_features(sess: &Session, diagnostics: bool) -> Vec<Stri
                     sess.dcx().emit_warn(unknown_feature);
                 }
                 Some(&(_, stability, _)) => {
-                    if let Err(reason) = stability.toggle_allowed() {
-                        sess.dcx().emit_warn(ForbiddenCTargetFeature {
-                            feature,
-                            enabled: if enable { "enabled" } else { "disabled" },
-                            reason,
-                        });
-                    } else if stability.requires_nightly().is_some() {
-                        // An unstable feature. Warn about using it. (It makes little sense
-                        // to hard-error here since we just warn about fully unknown
-                        // features above).
-                        sess.dcx().emit_warn(UnstableCTargetFeature { feature });
-                    }
+                    stability.verify_feature_enabled_by_flag(sess, enable, feature);
                 }
             }