diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_abi/src/extern_abi.rs | 25 | ||||
| -rw-r--r-- | compiler/rustc_abi/src/lib.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_ast_passes/messages.ftl | 2 | ||||
| -rw-r--r-- | compiler/rustc_feature/src/accepted.rs | 3 | ||||
| -rw-r--r-- | compiler/rustc_feature/src/unstable.rs | 3 | ||||
| -rw-r--r-- | compiler/rustc_hir_analysis/src/check/check.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_hir_analysis/src/check/mod.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs | 4 | ||||
| -rw-r--r-- | compiler/rustc_hir_analysis/src/lib.rs | 59 |
9 files changed, 55 insertions, 47 deletions
diff --git a/compiler/rustc_abi/src/extern_abi.rs b/compiler/rustc_abi/src/extern_abi.rs index 41d744e1946..e3b2b1eff72 100644 --- a/compiler/rustc_abi/src/extern_abi.rs +++ b/compiler/rustc_abi/src/extern_abi.rs @@ -6,6 +6,8 @@ use std::hash::{Hash, Hasher}; use rustc_data_structures::stable_hasher::{HashStable, StableHasher, StableOrd}; #[cfg(feature = "nightly")] use rustc_macros::{Decodable, Encodable}; +#[cfg(feature = "nightly")] +use rustc_span::Symbol; use crate::AbiFromStrErr; @@ -226,6 +228,13 @@ impl StableOrd for ExternAbi { #[cfg(feature = "nightly")] rustc_error_messages::into_diag_arg_using_display!(ExternAbi); +#[cfg(feature = "nightly")] +pub enum CVariadicStatus { + NotSupported, + Stable, + Unstable { feature: Symbol }, +} + impl ExternAbi { /// An ABI "like Rust" /// @@ -238,23 +247,33 @@ impl ExternAbi { matches!(self, Rust | RustCall | RustCold) } - pub fn supports_varargs(self) -> bool { + /// Returns whether the ABI supports C variadics. This only controls whether we allow *imports* + /// of such functions via `extern` blocks; there's a separate check during AST construction + /// guarding *definitions* of variadic functions. + #[cfg(feature = "nightly")] + pub fn supports_c_variadic(self) -> CVariadicStatus { // * C and Cdecl obviously support varargs. // * C can be based on Aapcs, SysV64 or Win64, so they must support varargs. // * EfiApi is based on Win64 or C, so it also supports it. + // * System automatically falls back to C when used with variadics, therefore supports it. // // * Stdcall does not, because it would be impossible for the callee to clean // up the arguments. (callee doesn't know how many arguments are there) // * Same for Fastcall, Vectorcall and Thiscall. // * Other calling conventions are related to hardware or the compiler itself. + // + // All of the supported ones must have a test in `tests/codegen/cffi/c-variadic-ffi.rs`. match self { Self::C { .. } | Self::Cdecl { .. } | Self::Aapcs { .. } | Self::Win64 { .. } | Self::SysV64 { .. } - | Self::EfiApi => true, - _ => false, + | Self::EfiApi => CVariadicStatus::Stable, + Self::System { .. } => { + CVariadicStatus::Unstable { feature: rustc_span::sym::extern_system_varargs } + } + _ => CVariadicStatus::NotSupported, } } } diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs index 14e256b8045..22aba1fac0f 100644 --- a/compiler/rustc_abi/src/lib.rs +++ b/compiler/rustc_abi/src/lib.rs @@ -63,6 +63,8 @@ mod tests; pub use callconv::{Heterogeneous, HomogeneousAggregate, Reg, RegKind}; pub use canon_abi::{ArmCall, CanonAbi, InterruptKind, X86Call}; +#[cfg(feature = "nightly")] +pub use extern_abi::CVariadicStatus; pub use extern_abi::{ExternAbi, all_names}; #[cfg(feature = "nightly")] pub use layout::{FIRST_VARIANT, FieldIdx, Layout, TyAbiInterface, TyAndLayout, VariantIdx}; diff --git a/compiler/rustc_ast_passes/messages.ftl b/compiler/rustc_ast_passes/messages.ftl index a95f1443968..e5f1fcdc4b4 100644 --- a/compiler/rustc_ast_passes/messages.ftl +++ b/compiler/rustc_ast_passes/messages.ftl @@ -57,7 +57,7 @@ ast_passes_auto_super_lifetime = auto traits cannot have super traits or lifetim .label = {ast_passes_auto_super_lifetime} .suggestion = remove the super traits or lifetime bounds -ast_passes_bad_c_variadic = only foreign, `unsafe extern "C"`, or `unsafe extern "C-unwind"` functions may have a C-variadic arg +ast_passes_bad_c_variadic = defining functions with C-variadic arguments is only allowed for free functions with the "C" or "C-unwind" calling convention ast_passes_body_in_extern = incorrect `{$kind}` inside `extern` block .cannot_have = cannot have a body diff --git a/compiler/rustc_feature/src/accepted.rs b/compiler/rustc_feature/src/accepted.rs index 9fe55216f93..6af4cfb0e56 100644 --- a/compiler/rustc_feature/src/accepted.rs +++ b/compiler/rustc_feature/src/accepted.rs @@ -203,6 +203,9 @@ declare_features! ( (accepted, expr_fragment_specifier_2024, "1.83.0", Some(123742)), /// Allows arbitrary expressions in key-value attributes at parse time. (accepted, extended_key_value_attributes, "1.54.0", Some(78835)), + /// Allows using `aapcs`, `efiapi`, `sysv64` and `win64` as calling conventions + /// for functions with varargs. + (accepted, extended_varargs_abi_support, "CURRENT_RUSTC_VERSION", Some(100189)), /// Allows resolving absolute paths as paths from other crates. (accepted, extern_absolute_paths, "1.30.0", Some(44660)), /// Allows `extern crate foo as bar;`. This puts `bar` into extern prelude. diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs index 92b435b4b01..573e9aab055 100644 --- a/compiler/rustc_feature/src/unstable.rs +++ b/compiler/rustc_feature/src/unstable.rs @@ -492,9 +492,6 @@ declare_features! ( (incomplete, explicit_tail_calls, "1.72.0", Some(112788)), /// Allows using `#[export_stable]` which indicates that an item is exportable. (incomplete, export_stable, "1.88.0", Some(139939)), - /// Allows using `aapcs`, `efiapi`, `sysv64` and `win64` as calling conventions - /// for functions with varargs. - (unstable, extended_varargs_abi_support, "1.65.0", Some(100189)), /// Allows using `system` as a calling convention with varargs. (unstable, extern_system_varargs, "1.86.0", Some(136946)), /// Allows defining `extern type`s. diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs index eccb88a938f..08b344638dd 100644 --- a/compiler/rustc_hir_analysis/src/check/check.rs +++ b/compiler/rustc_hir_analysis/src/check/check.rs @@ -978,7 +978,7 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Result<(), tcx.ensure_ok().fn_sig(def_id); let item = tcx.hir_foreign_item(item); let hir::ForeignItemKind::Fn(sig, ..) = item.kind else { bug!() }; - require_c_abi_if_c_variadic(tcx, sig.decl, abi, item.span); + check_c_variadic_abi(tcx, sig.decl, abi, item.span); } DefKind::Static { .. } => { tcx.ensure_ok().codegen_fn_attrs(def_id); diff --git a/compiler/rustc_hir_analysis/src/check/mod.rs b/compiler/rustc_hir_analysis/src/check/mod.rs index 2e4b151d4dc..b5c0ca4727c 100644 --- a/compiler/rustc_hir_analysis/src/check/mod.rs +++ b/compiler/rustc_hir_analysis/src/check/mod.rs @@ -98,7 +98,7 @@ use tracing::debug; use self::compare_impl_item::collect_return_position_impl_trait_in_trait_tys; use self::region::region_scope_tree; -use crate::{errors, require_c_abi_if_c_variadic}; +use crate::{check_c_variadic_abi, errors}; /// Adds query implementations to the [Providers] vtable, see [`rustc_middle::query`] pub(super) fn provide(providers: &mut Providers) { diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs index c7b984d9b25..c5e079fe89a 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs @@ -52,11 +52,11 @@ use rustc_trait_selection::traits::{self, FulfillmentError}; use tracing::{debug, instrument}; use crate::check::check_abi; +use crate::check_c_variadic_abi; use crate::errors::{AmbiguousLifetimeBound, BadReturnTypeNotation}; use crate::hir_ty_lowering::errors::{GenericsArgsErrExtend, prohibit_assoc_item_constraint}; use crate::hir_ty_lowering::generics::{check_generic_arg_count, lower_generic_args}; use crate::middle::resolve_bound_vars as rbv; -use crate::require_c_abi_if_c_variadic; /// A path segment that is semantically allowed to have generic arguments. #[derive(Debug)] @@ -2412,7 +2412,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { Ty::new_tup_from_iter(tcx, fields.iter().map(|t| self.lower_ty(t))) } hir::TyKind::FnPtr(bf) => { - require_c_abi_if_c_variadic(tcx, bf.decl, bf.abi, hir_ty.span); + check_c_variadic_abi(tcx, bf.decl, bf.abi, hir_ty.span); Ty::new_fn_ptr( tcx, diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs index 44a5ceed469..2562ab7542a 100644 --- a/compiler/rustc_hir_analysis/src/lib.rs +++ b/compiler/rustc_hir_analysis/src/lib.rs @@ -90,7 +90,7 @@ mod outlives; mod variance; pub use errors::NoVariantNamed; -use rustc_abi::ExternAbi; +use rustc_abi::{CVariadicStatus, ExternAbi}; use rustc_hir::def::DefKind; use rustc_hir::lints::DelayedLint; use rustc_hir::{self as hir}; @@ -99,7 +99,6 @@ use rustc_middle::mir::interpret::GlobalId; use rustc_middle::query::Providers; use rustc_middle::ty::{self, Const, Ty, TyCtxt}; use rustc_session::parse::feature_err; -use rustc_span::symbol::sym; use rustc_span::{ErrorGuaranteed, Span}; use rustc_trait_selection::traits; @@ -108,46 +107,34 @@ use crate::hir_ty_lowering::{FeedConstTy, HirTyLowerer}; rustc_fluent_macro::fluent_messages! { "../messages.ftl" } -fn require_c_abi_if_c_variadic( - tcx: TyCtxt<'_>, - decl: &hir::FnDecl<'_>, - abi: ExternAbi, - span: Span, -) { - // ABIs which can stably use varargs - if !decl.c_variadic || matches!(abi, ExternAbi::C { .. } | ExternAbi::Cdecl { .. }) { +fn check_c_variadic_abi(tcx: TyCtxt<'_>, decl: &hir::FnDecl<'_>, abi: ExternAbi, span: Span) { + if !decl.c_variadic { + // Not even a variadic function. return; } - // ABIs with feature-gated stability - let extended_abi_support = tcx.features().extended_varargs_abi_support(); - let extern_system_varargs = tcx.features().extern_system_varargs(); - - // If the feature gate has been enabled, we can stop here - if extern_system_varargs && let ExternAbi::System { .. } = abi { - return; - }; - if extended_abi_support && abi.supports_varargs() { - return; - }; - - // Looks like we need to pick an error to emit. - // Is there any feature which we could have enabled to make this work? - let unstable_explain = - format!("C-variadic functions with the {abi} calling convention are unstable"); - match abi { - ExternAbi::System { .. } => { - feature_err(&tcx.sess, sym::extern_system_varargs, span, unstable_explain) + match abi.supports_c_variadic() { + CVariadicStatus::Stable => {} + CVariadicStatus::NotSupported => { + tcx.dcx() + .create_err(errors::VariadicFunctionCompatibleConvention { + span, + convention: &format!("{abi}"), + }) + .emit(); } - abi if abi.supports_varargs() => { - feature_err(&tcx.sess, sym::extended_varargs_abi_support, span, unstable_explain) + CVariadicStatus::Unstable { feature } => { + if !tcx.features().enabled(feature) { + feature_err( + &tcx.sess, + feature, + span, + format!("C-variadic functions with the {abi} calling convention are unstable"), + ) + .emit(); + } } - _ => tcx.dcx().create_err(errors::VariadicFunctionCompatibleConvention { - span, - convention: &format!("{abi}"), - }), } - .emit(); } /// Adds query implementations to the [Providers] vtable, see [`rustc_middle::query`] |