From 072ccce553dd83ebfdf0aaf99eb24f65133c368b Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Mon, 17 Mar 2025 22:59:56 +0100 Subject: [PATCH] make -Zwasm-c-abi=legacy suppress the lint --- compiler/rustc_codegen_ssa/src/mir/naked_asm.rs | 4 ++-- compiler/rustc_monomorphize/src/mono_checks/abi_check.rs | 9 +++++---- compiler/rustc_session/src/options.rs | 5 +++-- compiler/rustc_target/src/callconv/mod.rs | 2 +- compiler/rustc_target/src/spec/mod.rs | 5 ++++- 5 files changed, 15 insertions(+), 10 deletions(-) diff --git a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs index bc9cde1b2a15..3a6b1f8d4efc 100644 --- a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs +++ b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs @@ -332,7 +332,7 @@ fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, def_id // please also add `wasm32-unknown-unknown` back in `tests/assembly/wasm32-naked-fn.rs` // basically the commit introducing this comment should be reverted if let PassMode::Pair { .. } = fn_abi.ret.mode { - let _ = WasmCAbi::Legacy; + let _ = WasmCAbi::Legacy { with_lint: true }; span_bug!( tcx.def_span(def_id), "cannot return a pair (the wasm32-unknown-unknown ABI is broken, see https://github.com/rust-lang/rust/issues/115666" @@ -384,7 +384,7 @@ fn wasm_type<'tcx>( BackendRepr::SimdVector { .. } => "v128", BackendRepr::Memory { .. } => { // FIXME: remove this branch once the wasm32-unknown-unknown ABI is fixed - let _ = WasmCAbi::Legacy; + let _ = WasmCAbi::Legacy { with_lint: true }; span_bug!( tcx.def_span(def_id), "cannot use memory args (the wasm32-unknown-unknown ABI is broken, see https://github.com/rust-lang/rust/issues/115666" diff --git a/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs b/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs index f17f7261df58..40740c3fdf65 100644 --- a/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs +++ b/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs @@ -92,6 +92,7 @@ fn do_check_simd_vector_abi<'tcx>( } } +/// Determines whether the given argument is passed the same way on the old and new wasm ABIs. fn wasm_abi_safe<'tcx>(tcx: TyCtxt<'tcx>, arg: &ArgAbi<'tcx, Ty<'tcx>>) -> bool { if matches!(arg.layout.backend_repr, BackendRepr::Scalar(_)) { return true; @@ -120,16 +121,16 @@ fn do_check_wasm_abi<'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`). + // 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`), + // and only proceed if `wasm_c_abi_opt` indicates we should emit the lint. if !(tcx.sess.target.arch == "wasm32" && tcx.sess.target.os == "unknown" - && tcx.wasm_c_abi_opt() == WasmCAbi::Legacy + && tcx.wasm_c_abi_opt() == WasmCAbi::Legacy { with_lint: true } && 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. + // Warn against all types whose ABI will change. Return values are not affected by this change. for arg_abi in abi.args.iter() { if wasm_abi_safe(tcx, arg_abi) { continue; diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index b3be4b611f03..828230f2fe66 100644 --- a/compiler/rustc_session/src/options.rs +++ b/compiler/rustc_session/src/options.rs @@ -1886,7 +1886,8 @@ pub mod parse { pub(crate) fn parse_wasm_c_abi(slot: &mut WasmCAbi, v: Option<&str>) -> bool { match v { Some("spec") => *slot = WasmCAbi::Spec, - Some("legacy") => *slot = WasmCAbi::Legacy, + // Explicitly setting the `-Z` flag suppresses the lint. + Some("legacy") => *slot = WasmCAbi::Legacy { with_lint: false }, _ => return false, } true @@ -2599,7 +2600,7 @@ written to standard error output)"), Requires `-Clto[=[fat,yes]]`"), wasi_exec_model: Option = (None, parse_wasi_exec_model, [TRACKED], "whether to build a wasi command or reactor"), - wasm_c_abi: WasmCAbi = (WasmCAbi::Legacy, parse_wasm_c_abi, [TRACKED], + wasm_c_abi: WasmCAbi = (WasmCAbi::Legacy { with_lint: true }, parse_wasm_c_abi, [TRACKED], "use spec-compliant C ABI for `wasm32-unknown-unknown` (default: legacy)"), write_long_types_to_disk: bool = (true, parse_bool, [UNTRACKED], "whether long type names should be written to files instead of being printed in errors"), diff --git a/compiler/rustc_target/src/callconv/mod.rs b/compiler/rustc_target/src/callconv/mod.rs index 6d0ee3c7ee58..a52b2b76bc1e 100644 --- a/compiler/rustc_target/src/callconv/mod.rs +++ b/compiler/rustc_target/src/callconv/mod.rs @@ -705,7 +705,7 @@ impl<'a, Ty> FnAbi<'a, Ty> { "xtensa" => xtensa::compute_abi_info(cx, self), "riscv32" | "riscv64" => riscv::compute_abi_info(cx, self), "wasm32" => { - if spec.os == "unknown" && cx.wasm_c_abi_opt() == WasmCAbi::Legacy { + if spec.os == "unknown" && matches!(cx.wasm_c_abi_opt(), WasmCAbi::Legacy { .. }) { wasm::compute_wasm_abi_info(self) } else { wasm::compute_c_abi_info(cx, self) diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs index 1887134c5757..1a823f47d9d9 100644 --- a/compiler/rustc_target/src/spec/mod.rs +++ b/compiler/rustc_target/src/spec/mod.rs @@ -2234,7 +2234,10 @@ pub enum WasmCAbi { /// Spec-compliant C ABI. Spec, /// Legacy ABI. Which is non-spec-compliant. - Legacy, + Legacy { + /// Indicates whether the `wasm_c_abi` lint should be emitted. + with_lint: bool, + }, } pub trait HasWasmCAbiOpt {