diff options
| -rw-r--r-- | compiler/rustc_lint_defs/src/builtin.rs | 46 | ||||
| -rw-r--r-- | compiler/rustc_monomorphize/messages.ftl | 7 | ||||
| -rw-r--r-- | compiler/rustc_monomorphize/src/errors.rs | 9 | ||||
| -rw-r--r-- | compiler/rustc_monomorphize/src/mono_checks/abi_check.rs | 80 | ||||
| -rw-r--r-- | compiler/rustc_target/src/callconv/wasm.rs | 3 | ||||
| -rw-r--r-- | tests/ui/abi/compatibility.rs | 1 | ||||
| -rw-r--r-- | tests/ui/lint/wasm_c_abi_transition.rs | 41 | ||||
| -rw-r--r-- | tests/ui/lint/wasm_c_abi_transition.stderr | 85 |
8 files changed, 259 insertions, 13 deletions
diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index 592c934997c..8a761a0a096 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -143,6 +143,7 @@ declare_lint_pass! { UNUSED_VARIABLES, USELESS_DEPRECATED, WARNINGS, + WASM_C_ABI, // tidy-alphabetical-end ] } @@ -5082,6 +5083,8 @@ declare_lint! { /// } /// ``` /// + /// This will produce: + /// /// ```text /// warning: ABI error: this function call uses a avx vector type, which is not enabled in the caller /// --> lint_example.rs:18:12 @@ -5125,3 +5128,46 @@ declare_lint! { reference: "issue #116558 <https://github.com/rust-lang/rust/issues/116558>", }; } + +declare_lint! { + /// The `wasm_c_abi` lint detects usage of the `extern "C"` ABI of wasm that is affected + /// by a planned ABI change that has the goal of aligning Rust with the standard C ABI + /// of this target. + /// + /// ### Example + /// + /// ```rust,ignore (needs wasm32-unknown-unknown) + /// #[repr(C)] + /// struct MyType(i32, i32); + /// + /// extern "C" my_fun(x: MyType) {} + /// ``` + /// + /// This will produce: + /// + /// ```text + /// error: this function function definition is affected by the wasm ABI transition: it passes an argument of non-scalar type `MyType` + /// --> $DIR/wasm_c_abi_transition.rs:17:1 + /// | + /// | pub extern "C" fn my_fun(_x: MyType) {} + /// | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + /// | + /// = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + /// = note: for more information, see issue #138762 <https://github.com/rust-lang/rust/issues/138762> + /// = help: the "C" ABI Rust uses on wasm32-unknown-unknown will change to align with the standard "C" ABI for this target + /// ``` + /// + /// ### Explanation + /// + /// Rust has historically implemented a non-spec-compliant C ABI on wasm32-unknown-unknown. This + /// has caused incompatibilities with other compilers and Wasm targets. In a future version + /// of Rust, this will be fixed, and therefore code relying on the non-spec-compliant C ABI will + /// stop functioning. + pub WASM_C_ABI, + Warn, + "detects code relying on rustc's non-spec-compliant wasm C ABI", + @future_incompatible = FutureIncompatibleInfo { + reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps, + reference: "issue #138762 <https://github.com/rust-lang/rust/issues/138762>", + }; +} diff --git a/compiler/rustc_monomorphize/messages.ftl b/compiler/rustc_monomorphize/messages.ftl index bdeab12ab50..aae2d79c161 100644 --- a/compiler/rustc_monomorphize/messages.ftl +++ b/compiler/rustc_monomorphize/messages.ftl @@ -63,4 +63,11 @@ monomorphize_symbol_already_defined = symbol `{$symbol}` is already defined monomorphize_unknown_cgu_collection_mode = unknown codegen-item collection mode '{$mode}', falling back to 'lazy' mode +monomorphize_wasm_c_abi_transition = + this function {$is_call -> + [true] call + *[false] definition + } involves an argument of type `{$ty}` which is affected by the wasm ABI transition + .help = the "C" ABI Rust uses on wasm32-unknown-unknown will change to align with the standard "C" ABI for this target + monomorphize_written_to_path = the full type name has been written to '{$path}' diff --git a/compiler/rustc_monomorphize/src/errors.rs b/compiler/rustc_monomorphize/src/errors.rs index 8dafbbca905..dffa372279f 100644 --- a/compiler/rustc_monomorphize/src/errors.rs +++ b/compiler/rustc_monomorphize/src/errors.rs @@ -103,3 +103,12 @@ pub(crate) struct AbiRequiredTargetFeature<'a> { /// Whether this is a problem at a call site or at a declaration. pub is_call: bool, } + +#[derive(LintDiagnostic)] +#[diag(monomorphize_wasm_c_abi_transition)] +#[help] +pub(crate) struct WasmCAbiTransition<'a> { + pub ty: Ty<'a>, + /// Whether this is a problem at a call site or at a declaration. + pub is_call: bool, +} diff --git a/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs b/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs index 06d6c3ab805..f17f7261df5 100644 --- a/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs +++ b/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs @@ -3,11 +3,13 @@ use rustc_abi::{BackendRepr, RegKind}; use rustc_hir::CRATE_HIR_ID; use rustc_middle::mir::{self, traversal}; -use rustc_middle::ty::{self, Instance, InstanceKind, Ty, TyCtxt}; -use rustc_session::lint::builtin::ABI_UNSUPPORTED_VECTOR_TYPES; +use rustc_middle::ty::layout::LayoutCx; +use rustc_middle::ty::{self, Instance, InstanceKind, Ty, TyCtxt, TypingEnv}; +use rustc_session::lint::builtin::{ABI_UNSUPPORTED_VECTOR_TYPES, WASM_C_ABI}; use rustc_span::def_id::DefId; use rustc_span::{DUMMY_SP, Span, Symbol, sym}; -use rustc_target::callconv::{Conv, FnAbi, PassMode}; +use rustc_target::callconv::{ArgAbi, Conv, FnAbi, PassMode}; +use rustc_target::spec::{HasWasmCAbiOpt, WasmCAbi}; use crate::errors; @@ -26,13 +28,15 @@ fn uses_vector_registers(mode: &PassMode, repr: &BackendRepr) -> bool { /// for a certain function. /// `is_call` indicates whether this is a call-site check or a definition-site check; /// this is only relevant for the wording in the emitted error. -fn do_check_abi<'tcx>( +fn do_check_simd_vector_abi<'tcx>( tcx: TyCtxt<'tcx>, abi: &FnAbi<'tcx, Ty<'tcx>>, def_id: DefId, is_call: bool, span: impl Fn() -> Span, ) { + // We check this on all functions, including those using the "Rust" ABI. + // For the "Rust" ABI it would be a bug if the lint ever triggered, but better safe than sorry. let feature_def = tcx.sess.target.features_for_correct_vector_abi(); let codegen_attrs = tcx.codegen_fn_attrs(def_id); let have_feature = |feat: Symbol| { @@ -88,6 +92,60 @@ fn do_check_abi<'tcx>( } } +fn wasm_abi_safe<'tcx>(tcx: TyCtxt<'tcx>, arg: &ArgAbi<'tcx, Ty<'tcx>>) -> bool { + if matches!(arg.layout.backend_repr, BackendRepr::Scalar(_)) { + return true; + } + + // This matches `unwrap_trivial_aggregate` in the wasm ABI logic. + if arg.layout.is_aggregate() { + let cx = LayoutCx::new(tcx, TypingEnv::fully_monomorphized()); + if let Some(unit) = arg.layout.homogeneous_aggregate(&cx).ok().and_then(|ha| ha.unit()) { + let size = arg.layout.size; + // Ensure there's just a single `unit` element in `arg`. + if unit.size == size { + return true; + } + } + } + + false +} + +/// Warns against usage of `extern "C"` on wasm32-unknown-unknown that is affected by the +/// ABI transition. +fn do_check_wasm_abi<'tcx>( + tcx: TyCtxt<'tcx>, + abi: &FnAbi<'tcx, Ty<'tcx>>, + is_call: bool, + span: impl Fn() -> Span, +) { + // Only proceed for `extern "C" fn` on wasm32-unknown-unknown (same check as what `adjust_for_foreign_abi` uses to call `compute_wasm_abi_info`). + if !(tcx.sess.target.arch == "wasm32" + && tcx.sess.target.os == "unknown" + && tcx.wasm_c_abi_opt() == WasmCAbi::Legacy + && abi.conv == Conv::C) + { + return; + } + // Warn against all types whose ABI will change. That's all arguments except for things passed as scalars. + // Return values are not affected by this change. + for arg_abi in abi.args.iter() { + if wasm_abi_safe(tcx, arg_abi) { + continue; + } + let span = span(); + tcx.emit_node_span_lint( + WASM_C_ABI, + CRATE_HIR_ID, + span, + errors::WasmCAbiTransition { ty: arg_abi.layout.ty, is_call }, + ); + // Let's only warn once per function. + break; + } +} + /// Checks that the ABI of a given instance of a function does not contain vector-passed arguments /// or return values for which the corresponding target feature is not enabled. fn check_instance_abi<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) { @@ -98,13 +156,10 @@ fn check_instance_abi<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) { // function. return; }; - do_check_abi( - tcx, - abi, - instance.def_id(), - /*is_call*/ false, - || tcx.def_span(instance.def_id()), - ) + do_check_simd_vector_abi(tcx, abi, instance.def_id(), /*is_call*/ false, || { + tcx.def_span(instance.def_id()) + }); + do_check_wasm_abi(tcx, abi, /*is_call*/ false, || tcx.def_span(instance.def_id())); } /// Checks that a call expression does not try to pass a vector-passed argument which requires a @@ -141,7 +196,8 @@ fn check_call_site_abi<'tcx>( // ABI failed to compute; this will not get through codegen. return; }; - do_check_abi(tcx, callee_abi, caller.def_id(), /*is_call*/ true, || span); + do_check_simd_vector_abi(tcx, callee_abi, caller.def_id(), /*is_call*/ true, || span); + do_check_wasm_abi(tcx, callee_abi, /*is_call*/ true, || span); } fn check_callees_abi<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>, body: &mir::Body<'tcx>) { diff --git a/compiler/rustc_target/src/callconv/wasm.rs b/compiler/rustc_target/src/callconv/wasm.rs index 364a6551131..881168c98c3 100644 --- a/compiler/rustc_target/src/callconv/wasm.rs +++ b/compiler/rustc_target/src/callconv/wasm.rs @@ -10,6 +10,9 @@ where if val.layout.is_aggregate() { if let Some(unit) = val.layout.homogeneous_aggregate(cx).ok().and_then(|ha| ha.unit()) { let size = val.layout.size; + // This size check also catches over-aligned scalars as `size` will be rounded up to a + // multiple of the alignment, and the default alignment of all scalar types on wasm + // equals their size. if unit.size == size { val.cast_to(unit); return true; diff --git a/tests/ui/abi/compatibility.rs b/tests/ui/abi/compatibility.rs index 64e65ece85d..be649029c86 100644 --- a/tests/ui/abi/compatibility.rs +++ b/tests/ui/abi/compatibility.rs @@ -62,7 +62,6 @@ //@[nvptx64] needs-llvm-components: nvptx #![feature(no_core, rustc_attrs, lang_items)] #![feature(unsized_fn_params, transparent_unions)] -#![no_std] #![no_core] #![allow(unused, improper_ctypes_definitions, internal_features)] diff --git a/tests/ui/lint/wasm_c_abi_transition.rs b/tests/ui/lint/wasm_c_abi_transition.rs new file mode 100644 index 00000000000..1fe81679e65 --- /dev/null +++ b/tests/ui/lint/wasm_c_abi_transition.rs @@ -0,0 +1,41 @@ +//@ compile-flags: --target wasm32-unknown-unknown +//@ needs-llvm-components: webassembly +//@ add-core-stubs +//@ build-fail + +#![feature(no_core)] +#![no_core] +#![crate_type = "lib"] +#![deny(wasm_c_abi)] + +extern crate minicore; +use minicore::*; + +pub extern "C" fn my_fun_trivial(_x: i32, _y: f32) {} + +#[repr(C)] +pub struct MyType(i32, i32); +pub extern "C" fn my_fun(_x: MyType) {} //~ERROR: wasm ABI transition +//~^WARN: previously accepted + +// This one is ABI-safe as it only wraps a single field, +// and the return type can be anything. +#[repr(C)] +pub struct MySafeType(i32); +pub extern "C" fn my_fun_safe(_x: MySafeType) -> MyType { loop {} } + +// This one not ABI-safe due to the alignment. +#[repr(C, align(16))] +pub struct MyAlignedType(i32); +pub extern "C" fn my_fun_aligned(_x: MyAlignedType) {} //~ERROR: wasm ABI transition +//~^WARN: previously accepted + +// Check call-site warning +extern "C" { + fn other_fun(x: MyType); +} + +pub fn call_other_fun(x: MyType) { + unsafe { other_fun(x) } //~ERROR: wasm ABI transition + //~^WARN: previously accepted +} diff --git a/tests/ui/lint/wasm_c_abi_transition.stderr b/tests/ui/lint/wasm_c_abi_transition.stderr new file mode 100644 index 00000000000..389710d5cb3 --- /dev/null +++ b/tests/ui/lint/wasm_c_abi_transition.stderr @@ -0,0 +1,85 @@ +error: this function definition involves an argument of type `MyType` which is affected by the wasm ABI transition + --> $DIR/wasm_c_abi_transition.rs:18:1 + | +LL | pub extern "C" fn my_fun(_x: MyType) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #138762 <https://github.com/rust-lang/rust/issues/138762> + = help: the "C" ABI Rust uses on wasm32-unknown-unknown will change to align with the standard "C" ABI for this target +note: the lint level is defined here + --> $DIR/wasm_c_abi_transition.rs:9:9 + | +LL | #![deny(wasm_c_abi)] + | ^^^^^^^^^^ + +error: this function definition involves an argument of type `MyAlignedType` which is affected by the wasm ABI transition + --> $DIR/wasm_c_abi_transition.rs:30:1 + | +LL | pub extern "C" fn my_fun_aligned(_x: MyAlignedType) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #138762 <https://github.com/rust-lang/rust/issues/138762> + = help: the "C" ABI Rust uses on wasm32-unknown-unknown will change to align with the standard "C" ABI for this target + +error: this function call involves an argument of type `MyType` which is affected by the wasm ABI transition + --> $DIR/wasm_c_abi_transition.rs:39:14 + | +LL | unsafe { other_fun(x) } + | ^^^^^^^^^^^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #138762 <https://github.com/rust-lang/rust/issues/138762> + = help: the "C" ABI Rust uses on wasm32-unknown-unknown will change to align with the standard "C" ABI for this target + +error: aborting due to 3 previous errors + +Future incompatibility report: Future breakage diagnostic: +error: this function definition involves an argument of type `MyType` which is affected by the wasm ABI transition + --> $DIR/wasm_c_abi_transition.rs:18:1 + | +LL | pub extern "C" fn my_fun(_x: MyType) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #138762 <https://github.com/rust-lang/rust/issues/138762> + = help: the "C" ABI Rust uses on wasm32-unknown-unknown will change to align with the standard "C" ABI for this target +note: the lint level is defined here + --> $DIR/wasm_c_abi_transition.rs:9:9 + | +LL | #![deny(wasm_c_abi)] + | ^^^^^^^^^^ + +Future breakage diagnostic: +error: this function definition involves an argument of type `MyAlignedType` which is affected by the wasm ABI transition + --> $DIR/wasm_c_abi_transition.rs:30:1 + | +LL | pub extern "C" fn my_fun_aligned(_x: MyAlignedType) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #138762 <https://github.com/rust-lang/rust/issues/138762> + = help: the "C" ABI Rust uses on wasm32-unknown-unknown will change to align with the standard "C" ABI for this target +note: the lint level is defined here + --> $DIR/wasm_c_abi_transition.rs:9:9 + | +LL | #![deny(wasm_c_abi)] + | ^^^^^^^^^^ + +Future breakage diagnostic: +error: this function call involves an argument of type `MyType` which is affected by the wasm ABI transition + --> $DIR/wasm_c_abi_transition.rs:39:14 + | +LL | unsafe { other_fun(x) } + | ^^^^^^^^^^^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #138762 <https://github.com/rust-lang/rust/issues/138762> + = help: the "C" ABI Rust uses on wasm32-unknown-unknown will change to align with the standard "C" ABI for this target +note: the lint level is defined here + --> $DIR/wasm_c_abi_transition.rs:9:9 + | +LL | #![deny(wasm_c_abi)] + | ^^^^^^^^^^ + |