rustc_codegen_ssa/traits/
backend.rs

1use std::any::Any;
2use std::hash::Hash;
3
4use rustc_ast::expand::allocator::AllocatorMethod;
5use rustc_data_structures::fx::FxIndexMap;
6use rustc_data_structures::sync::{DynSend, DynSync};
7use rustc_metadata::EncodedMetadata;
8use rustc_metadata::creader::MetadataLoaderDyn;
9use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
10use rustc_middle::ty::TyCtxt;
11use rustc_middle::util::Providers;
12use rustc_session::Session;
13use rustc_session::config::{self, CrateType, OutputFilenames, PrintRequest};
14use rustc_span::Symbol;
15
16use super::CodegenObject;
17use super::write::WriteBackendMethods;
18use crate::back::archive::ArArchiveBuilderBuilder;
19use crate::back::link::link_binary;
20use crate::back::write::TargetMachineFactoryFn;
21use crate::{CodegenResults, ModuleCodegen, TargetConfig};
22
23pub trait BackendTypes {
24    type Value: CodegenObject + PartialEq;
25    type Metadata: CodegenObject;
26    type Function: CodegenObject;
27
28    type BasicBlock: Copy;
29    type Type: CodegenObject + PartialEq;
30    type Funclet;
31
32    // FIXME(eddyb) find a common convention for all of the debuginfo-related
33    // names (choose between `Dbg`, `Debug`, `DebugInfo`, `DI` etc.).
34    type DIScope: Copy + Hash + PartialEq + Eq;
35    type DILocation: Copy;
36    type DIVariable: Copy;
37}
38
39pub trait CodegenBackend {
40    fn name(&self) -> &'static str;
41
42    fn init(&self, _sess: &Session) {}
43
44    fn print(&self, _req: &PrintRequest, _out: &mut String, _sess: &Session) {}
45
46    /// Collect target-specific options that should be set in `cfg(...)`, including
47    /// `target_feature` and support for unstable float types.
48    fn target_config(&self, _sess: &Session) -> TargetConfig {
49        TargetConfig {
50            target_features: ::alloc::vec::Vec::new()vec![],
51            unstable_target_features: ::alloc::vec::Vec::new()vec![],
52            // `true` is used as a default so backends need to acknowledge when they do not
53            // support the float types, rather than accidentally quietly skipping all tests.
54            has_reliable_f16: true,
55            has_reliable_f16_math: true,
56            has_reliable_f128: true,
57            has_reliable_f128_math: true,
58        }
59    }
60
61    fn supported_crate_types(&self, _sess: &Session) -> Vec<CrateType> {
62        <[_]>::into_vec(::alloc::boxed::box_new([CrateType::Executable,
                CrateType::Dylib, CrateType::Rlib, CrateType::StaticLib,
                CrateType::Cdylib, CrateType::ProcMacro, CrateType::Sdylib]))vec![
63            CrateType::Executable,
64            CrateType::Dylib,
65            CrateType::Rlib,
66            CrateType::StaticLib,
67            CrateType::Cdylib,
68            CrateType::ProcMacro,
69            CrateType::Sdylib,
70        ]
71    }
72
73    fn print_passes(&self) {}
74
75    fn print_version(&self) {}
76
77    /// Returns a list of all intrinsics that this backend definitely
78    /// replaces, which means their fallback bodies do not need to be monomorphized.
79    fn replaced_intrinsics(&self) -> Vec<Symbol> {
80        ::alloc::vec::Vec::new()vec![]
81    }
82
83    /// Value printed by `--print=backend-has-zstd`.
84    ///
85    /// Used by compiletest to determine whether tests involving zstd compression
86    /// (e.g. `-Zdebuginfo-compression=zstd`) should be executed or skipped.
87    fn has_zstd(&self) -> bool {
88        false
89    }
90
91    /// The metadata loader used to load rlib and dylib metadata.
92    ///
93    /// Alternative codegen backends may want to use different rlib or dylib formats than the
94    /// default native static archives and dynamic libraries.
95    fn metadata_loader(&self) -> Box<MetadataLoaderDyn> {
96        Box::new(crate::back::metadata::DefaultMetadataLoader)
97    }
98
99    fn provide(&self, _providers: &mut Providers) {}
100
101    fn codegen_crate<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Box<dyn Any>;
102
103    /// This is called on the returned `Box<dyn Any>` from [`codegen_crate`](Self::codegen_crate)
104    ///
105    /// # Panics
106    ///
107    /// Panics when the passed `Box<dyn Any>` was not returned by [`codegen_crate`](Self::codegen_crate).
108    fn join_codegen(
109        &self,
110        ongoing_codegen: Box<dyn Any>,
111        sess: &Session,
112        outputs: &OutputFilenames,
113    ) -> (CodegenResults, FxIndexMap<WorkProductId, WorkProduct>);
114
115    /// This is called on the returned [`CodegenResults`] from [`join_codegen`](Self::join_codegen).
116    fn link(
117        &self,
118        sess: &Session,
119        codegen_results: CodegenResults,
120        metadata: EncodedMetadata,
121        outputs: &OutputFilenames,
122    ) {
123        link_binary(
124            sess,
125            &ArArchiveBuilderBuilder,
126            codegen_results,
127            metadata,
128            outputs,
129            self.name(),
130        );
131    }
132}
133
134pub trait ExtraBackendMethods:
135    CodegenBackend + WriteBackendMethods + Sized + Send + Sync + DynSend + DynSync
136{
137    fn codegen_allocator<'tcx>(
138        &self,
139        tcx: TyCtxt<'tcx>,
140        module_name: &str,
141        methods: &[AllocatorMethod],
142    ) -> Self::Module;
143
144    /// This generates the codegen unit and returns it along with
145    /// a `u64` giving an estimate of the unit's processing cost.
146    fn compile_codegen_unit(
147        &self,
148        tcx: TyCtxt<'_>,
149        cgu_name: Symbol,
150    ) -> (ModuleCodegen<Self::Module>, u64);
151
152    fn target_machine_factory(
153        &self,
154        sess: &Session,
155        opt_level: config::OptLevel,
156        target_features: &[String],
157    ) -> TargetMachineFactoryFn<Self>;
158
159    fn spawn_named_thread<F, T>(
160        _time_trace: bool,
161        name: String,
162        f: F,
163    ) -> std::io::Result<std::thread::JoinHandle<T>>
164    where
165        F: FnOnce() -> T,
166        F: Send + 'static,
167        T: Send + 'static,
168    {
169        std::thread::Builder::new().name(name).spawn(f)
170    }
171
172    /// Returns `true` if this backend can be safely called from multiple threads.
173    ///
174    /// Defaults to `true`.
175    fn supports_parallel(&self) -> bool {
176        true
177    }
178}
rustc_codegen_ssa/traits/backend.rs

rustc_codegen_ssa/traits/
backend.rs
