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| 1 | +use rustc_abi::Abi; |
| 2 | +use rustc_middle::ty::{self, Instance, InstanceKind, ParamEnv, Ty, TyCtxt}; |
| 3 | +use rustc_span::def_id::DefId; |
| 4 | +use rustc_span::{Span, Symbol}; |
| 5 | +use rustc_target::abi::call::{FnAbi, PassMode}; |
| 6 | + |
| 7 | +use crate::errors::{AbiErrorDisabledVectorTypeCall, AbiErrorDisabledVectorTypeDef}; |
| 8 | + |
| 9 | +// Represents the least-constraining feature that is required for vector types up to a certain size |
| 10 | +// to have their "proper" ABI. |
| 11 | +const X86_VECTOR_FEATURES: &'static [(u64, &'static str)] = |
| 12 | + &[(128, "sse"), (256, "avx"), (512, "avx512f")]; |
| 13 | + |
| 14 | +fn do_check_abi<'tcx>( |
| 15 | + tcx: TyCtxt<'tcx>, |
| 16 | + abi: &FnAbi<'tcx, Ty<'tcx>>, |
| 17 | + target_feature_def: DefId, |
| 18 | + emit_err: impl Fn(&'static str), |
| 19 | +) { |
| 20 | + let feature_def = if tcx.sess.target.arch == "x86" || tcx.sess.target.arch == "x86_64" { |
| 21 | + X86_VECTOR_FEATURES |
| 22 | + } else if tcx.sess.target.arch == "aarch64" { |
| 23 | + // ABI on aarch64 does not depend on target features. |
| 24 | + return; |
| 25 | + } else { |
| 26 | + // FIXME: add support for non-tier1 architectures |
| 27 | + return; |
| 28 | + }; |
| 29 | + let codegen_attrs = tcx.codegen_fn_attrs(target_feature_def); |
| 30 | + for arg_abi in abi.args.iter().chain(std::iter::once(&abi.ret)) { |
| 31 | + let size = arg_abi.layout.size; |
| 32 | + if matches!(arg_abi.layout.abi, Abi::Vector { .. }) |
| 33 | + && !matches!(arg_abi.mode, PassMode::Indirect { .. }) |
| 34 | + { |
| 35 | + let feature = match feature_def.iter().find(|(bits, _)| size.bits() <= *bits) { |
| 36 | + Some((_, feature)) => feature, |
| 37 | + None => panic!("Unknown vector size: {}; arg = {:?}", size.bits(), arg_abi), |
| 38 | + }; |
| 39 | + let feature_sym = Symbol::intern(feature); |
| 40 | + if !tcx.sess.unstable_target_features.contains(&feature_sym) |
| 41 | + && !codegen_attrs.target_features.iter().any(|x| x.name == feature_sym) |
| 42 | + { |
| 43 | + emit_err(feature); |
| 44 | + } |
| 45 | + } |
| 46 | + } |
| 47 | +} |
| 48 | + |
| 49 | +/// Checks that the ABI of a given instance of a function does not contain vector-passed arguments |
| 50 | +/// or return values for which the corresponding target feature is not enabled. |
| 51 | +pub fn check_instance_abi<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) { |
| 52 | + let param_env = ParamEnv::reveal_all(); |
| 53 | + let Ok(abi) = tcx.fn_abi_of_instance(param_env.and((instance, ty::List::empty()))) else { |
| 54 | + // An error will be reported during codegen if we cannot determine the ABI of this |
| 55 | + // function. |
| 56 | + return; |
| 57 | + }; |
| 58 | + do_check_abi(tcx, abi, instance.def_id(), |required_feature| { |
| 59 | + tcx.dcx().emit_err(AbiErrorDisabledVectorTypeDef { |
| 60 | + span: tcx.def_span(instance.def_id()), |
| 61 | + required_feature, |
| 62 | + }); |
| 63 | + }) |
| 64 | +} |
| 65 | + |
| 66 | +/// Checks that a call expression does not try to pass a vector-passed argument which requires a |
| 67 | +/// target feature that the caller does not have, as doing so causes UB because of ABI mismatch. |
| 68 | +pub fn check_call_site_abi<'tcx>( |
| 69 | + tcx: TyCtxt<'tcx>, |
| 70 | + ty: Ty<'tcx>, |
| 71 | + span: Span, |
| 72 | + caller: InstanceKind<'tcx>, |
| 73 | +) { |
| 74 | + let param_env = ParamEnv::reveal_all(); |
| 75 | + let callee_abi = match *ty.kind() { |
| 76 | + ty::FnPtr(..) => tcx.fn_abi_of_fn_ptr(param_env.and((ty.fn_sig(tcx), ty::List::empty()))), |
| 77 | + ty::FnDef(def_id, args) => { |
| 78 | + // Intrinsics are handled separately by the compiler. |
| 79 | + if tcx.intrinsic(def_id).is_some() { |
| 80 | + return; |
| 81 | + } |
| 82 | + let instance = ty::Instance::expect_resolve(tcx, param_env, def_id, args, span); |
| 83 | + tcx.fn_abi_of_instance(param_env.and((instance, ty::List::empty()))) |
| 84 | + } |
| 85 | + _ => { |
| 86 | + panic!("Invalid function call"); |
| 87 | + } |
| 88 | + }; |
| 89 | + |
| 90 | + let Ok(callee_abi) = callee_abi else { |
| 91 | + // ABI failed to compute; this will not get through codegen. |
| 92 | + return; |
| 93 | + }; |
| 94 | + do_check_abi(tcx, callee_abi, caller.def_id(), |required_feature| { |
| 95 | + tcx.dcx().emit_err(AbiErrorDisabledVectorTypeCall { span, required_feature }); |
| 96 | + }) |
| 97 | +} |
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