Merge ref 'd087f112b7d1:/library/compiler-builtins' from https://github.com/rust-lang/rust

Pull recent changes from rust-lang/rust via Josh.

Upstream ref: d087f112b7d1323446c7b39a8b616aee7fa56b3d
Filtered ref: 2d43ce8ac022170e5383f7e5a188b55564b6566a

10 files changed, 25 insertions, 64 deletions

diff --git a/compiler/rustc_codegen_gcc/build_system/build_sysroot/Cargo.toml b/compiler/rustc_codegen_gcc/build_system/build_sysroot/Cargo.toml
index 24152070e64..931f6097abc 100644
--- a/compiler/rustc_codegen_gcc/build_system/build_sysroot/Cargo.toml
+++ b/compiler/rustc_codegen_gcc/build_system/build_sysroot/Cargo.toml
@@ -6,7 +6,6 @@ resolver = "2"
 
 [dependencies]
 core = { path = "./sysroot_src/library/core" }
-compiler_builtins = "0.1"
 alloc = { path = "./sysroot_src/library/alloc" }
 std = { path = "./sysroot_src/library/std", features = ["panic_unwind", "backtrace"] }
 test = { path = "./sysroot_src/library/test" }
@@ -16,6 +15,7 @@ proc_macro = { path = "./sysroot_src/library/proc_macro" }
 rustc-std-workspace-core = { path = "./sysroot_src/library/rustc-std-workspace-core" }
 rustc-std-workspace-alloc = { path = "./sysroot_src/library/rustc-std-workspace-alloc" }
 rustc-std-workspace-std = { path = "./sysroot_src/library/rustc-std-workspace-std" }
+compiler_builtins = { path = "./sysroot_src/library/compiler-builtins/compiler-builtins" }
 
 # For compiler-builtins we always use a high number of codegen units.
 # The goal here is to place every single intrinsic into its own object
diff --git a/compiler/rustc_codegen_gcc/example/alloc_system.rs b/compiler/rustc_codegen_gcc/example/alloc_system.rs
index 945d34063a6..4d70122496b 100644
--- a/compiler/rustc_codegen_gcc/example/alloc_system.rs
+++ b/compiler/rustc_codegen_gcc/example/alloc_system.rs
@@ -8,6 +8,7 @@
 // add fast paths for low alignment values.
 #[cfg(any(target_arch = "x86",
               target_arch = "arm",
+              target_arch = "loongarch32",
               target_arch = "m68k",
               target_arch = "mips",
               target_arch = "mips32r6",
diff --git a/compiler/rustc_codegen_gcc/example/mini_core.rs b/compiler/rustc_codegen_gcc/example/mini_core.rs
index d1d8e8fd5bc..aca1f0080ef 100644
--- a/compiler/rustc_codegen_gcc/example/mini_core.rs
+++ b/compiler/rustc_codegen_gcc/example/mini_core.rs
@@ -655,9 +655,9 @@ pub mod intrinsics {
     #[rustc_intrinsic]
     pub unsafe fn size_of_val<T: ?::Sized>(val: *const T) -> usize;
     #[rustc_intrinsic]
-    pub fn min_align_of<T>() -> usize;
+    pub fn align_of<T>() -> usize;
     #[rustc_intrinsic]
-    pub unsafe fn min_align_of_val<T: ?::Sized>(val: *const T) -> usize;
+    pub unsafe fn align_of_val<T: ?::Sized>(val: *const T) -> usize;
     #[rustc_intrinsic]
     pub unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize);
     #[rustc_intrinsic]
diff --git a/compiler/rustc_codegen_gcc/example/mini_core_hello_world.rs b/compiler/rustc_codegen_gcc/example/mini_core_hello_world.rs
index 4cbe66c5e4c..c3bd62e5897 100644
--- a/compiler/rustc_codegen_gcc/example/mini_core_hello_world.rs
+++ b/compiler/rustc_codegen_gcc/example/mini_core_hello_world.rs
@@ -153,7 +153,7 @@ fn main() {
     let slice = &[0, 1] as &[i32];
     let slice_ptr = slice as *const [i32] as *const i32;
 
-    let align = intrinsics::min_align_of::<*const i32>();
+    let align = intrinsics::align_of::<*const i32>();
     assert_eq!(slice_ptr as usize % align, 0);
 
     //return;
@@ -194,8 +194,8 @@ fn main() {
         assert_eq!(intrinsics::size_of_val(a) as u8, 8);
         assert_eq!(intrinsics::size_of_val(&0u32) as u8, 4);
 
-        assert_eq!(intrinsics::min_align_of::<u16>() as u8, 2);
-        assert_eq!(intrinsics::min_align_of_val(&a) as u8, intrinsics::min_align_of::<&str>() as u8);
+        assert_eq!(intrinsics::align_of::<u16>() as u8, 2);
+        assert_eq!(intrinsics::align_of_val(&a) as u8, intrinsics::align_of::<&str>() as u8);
 
         assert!(!intrinsics::needs_drop::<u8>());
         assert!(!intrinsics::needs_drop::<[u8]>());
diff --git a/compiler/rustc_codegen_gcc/messages.ftl b/compiler/rustc_codegen_gcc/messages.ftl
index 882fff8673a..18a8a5a1e04 100644
--- a/compiler/rustc_codegen_gcc/messages.ftl
+++ b/compiler/rustc_codegen_gcc/messages.ftl
@@ -2,12 +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_invalid_minimum_alignment =
-    invalid minimum global alignment: {$err}
-
-codegen_gcc_forbidden_ctarget_feature =
-    target feature `{$feature}` cannot be toggled with `-Ctarget-feature`: {$reason}
-
 codegen_gcc_unwinding_inline_asm =
     GCC backend does not support unwinding from inline asm
 
@@ -29,10 +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/consts.rs b/compiler/rustc_codegen_gcc/src/consts.rs
index deb13ddf755..1690641a5bc 100644
--- a/compiler/rustc_codegen_gcc/src/consts.rs
+++ b/compiler/rustc_codegen_gcc/src/consts.rs
@@ -18,7 +18,6 @@ use rustc_span::def_id::DefId;
 
 use crate::base;
 use crate::context::CodegenCx;
-use crate::errors::InvalidMinimumAlignment;
 use crate::type_of::LayoutGccExt;
 
 fn set_global_alignment<'gcc, 'tcx>(
@@ -29,13 +28,8 @@ fn set_global_alignment<'gcc, 'tcx>(
     // The target may require greater alignment for globals than the type does.
     // Note: GCC and Clang also allow `__attribute__((aligned))` on variables,
     // which can force it to be smaller. Rust doesn't support this yet.
-    if let Some(min) = cx.sess().target.min_global_align {
-        match Align::from_bits(min) {
-            Ok(min) => align = align.max(min),
-            Err(err) => {
-                cx.sess().dcx().emit_err(InvalidMinimumAlignment { err: err.to_string() });
-            }
-        }
+    if let Some(min_global) = cx.sess().target.min_global_align {
+        align = Ord::max(align, min_global);
     }
     gv.set_alignment(align.bytes() as i32);
 }
diff --git a/compiler/rustc_codegen_gcc/src/errors.rs b/compiler/rustc_codegen_gcc/src/errors.rs
index 1b59b9ac169..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)]
@@ -48,12 +33,6 @@ pub(crate) struct UnwindingInlineAsm {
 }
 
 #[derive(Diagnostic)]
-#[diag(codegen_gcc_invalid_minimum_alignment)]
-pub(crate) struct InvalidMinimumAlignment {
-    pub err: String,
-}
-
-#[derive(Diagnostic)]
 #[diag(codegen_gcc_copy_bitcode)]
 pub(crate) struct CopyBitcode {
     pub err: std::io::Error,
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);
                 }
             }
 
diff --git a/compiler/rustc_codegen_gcc/src/lib.rs b/compiler/rustc_codegen_gcc/src/lib.rs
index f79ba2dcfc7..0591ffa42e4 100644
--- a/compiler/rustc_codegen_gcc/src/lib.rs
+++ b/compiler/rustc_codegen_gcc/src/lib.rs
@@ -16,7 +16,7 @@
 #![allow(internal_features)]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
-#![feature(rustc_private, decl_macro, never_type, trusted_len)]
+#![feature(rustc_private)]
 #![allow(broken_intra_doc_links)]
 #![recursion_limit = "256"]
 #![warn(rust_2018_idioms)]