rustc_codegen_ssa/
lib.rs

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1// tidy-alphabetical-start
2#![allow(internal_features)]
3#![allow(rustc::diagnostic_outside_of_impl)]
4#![allow(rustc::untranslatable_diagnostic)]
5#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
6#![doc(rust_logo)]
7#![feature(assert_matches)]
8#![feature(box_patterns)]
9#![feature(debug_closure_helpers)]
10#![feature(file_buffered)]
11#![feature(if_let_guard)]
12#![feature(let_chains)]
13#![feature(negative_impls)]
14#![feature(rustdoc_internals)]
15#![feature(trait_alias)]
16#![feature(try_blocks)]
17#![warn(unreachable_pub)]
18// tidy-alphabetical-end
19
20//! This crate contains codegen code that is used by all codegen backends (LLVM and others).
21//! The backend-agnostic functions of this crate use functions defined in various traits that
22//! have to be implemented by each backend.
23
24use std::collections::BTreeSet;
25use std::io;
26use std::path::{Path, PathBuf};
27use std::sync::Arc;
28
29use rustc_ast as ast;
30use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
31use rustc_data_structures::unord::UnordMap;
32use rustc_hir::CRATE_HIR_ID;
33use rustc_hir::def_id::CrateNum;
34use rustc_macros::{Decodable, Encodable, HashStable};
35use rustc_middle::dep_graph::WorkProduct;
36use rustc_middle::lint::LintLevelSource;
37use rustc_middle::middle::debugger_visualizer::DebuggerVisualizerFile;
38use rustc_middle::middle::dependency_format::Dependencies;
39use rustc_middle::middle::exported_symbols::SymbolExportKind;
40use rustc_middle::ty::TyCtxt;
41use rustc_middle::util::Providers;
42use rustc_serialize::opaque::{FileEncoder, MemDecoder};
43use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
44use rustc_session::Session;
45use rustc_session::config::{CrateType, OutputFilenames, OutputType, RUST_CGU_EXT};
46use rustc_session::cstore::{self, CrateSource};
47use rustc_session::lint::Level;
48use rustc_session::lint::builtin::LINKER_MESSAGES;
49use rustc_session::utils::NativeLibKind;
50use rustc_span::Symbol;
51
52pub mod assert_module_sources;
53pub mod back;
54pub mod base;
55pub mod codegen_attrs;
56pub mod common;
57pub mod debuginfo;
58pub mod errors;
59pub mod meth;
60pub mod mir;
61pub mod mono_item;
62pub mod size_of_val;
63pub mod target_features;
64pub mod traits;
65
66rustc_fluent_macro::fluent_messages! { "../messages.ftl" }
67
68pub struct ModuleCodegen<M> {
69    /// The name of the module. When the crate may be saved between
70    /// compilations, incremental compilation requires that name be
71    /// unique amongst **all** crates. Therefore, it should contain
72    /// something unique to this crate (e.g., a module path) as well
73    /// as the crate name and disambiguator.
74    /// We currently generate these names via CodegenUnit::build_cgu_name().
75    pub name: String,
76    pub module_llvm: M,
77    pub kind: ModuleKind,
78}
79
80impl<M> ModuleCodegen<M> {
81    pub fn into_compiled_module(
82        self,
83        emit_obj: bool,
84        emit_dwarf_obj: bool,
85        emit_bc: bool,
86        emit_asm: bool,
87        emit_ir: bool,
88        outputs: &OutputFilenames,
89    ) -> CompiledModule {
90        let object = emit_obj.then(|| outputs.temp_path(OutputType::Object, Some(&self.name)));
91        let dwarf_object = emit_dwarf_obj.then(|| outputs.temp_path_dwo(Some(&self.name)));
92        let bytecode = emit_bc.then(|| outputs.temp_path(OutputType::Bitcode, Some(&self.name)));
93        let assembly = emit_asm.then(|| outputs.temp_path(OutputType::Assembly, Some(&self.name)));
94        let llvm_ir =
95            emit_ir.then(|| outputs.temp_path(OutputType::LlvmAssembly, Some(&self.name)));
96
97        CompiledModule {
98            name: self.name.clone(),
99            kind: self.kind,
100            object,
101            dwarf_object,
102            bytecode,
103            assembly,
104            llvm_ir,
105        }
106    }
107}
108
109#[derive(Debug, Encodable, Decodable)]
110pub struct CompiledModule {
111    pub name: String,
112    pub kind: ModuleKind,
113    pub object: Option<PathBuf>,
114    pub dwarf_object: Option<PathBuf>,
115    pub bytecode: Option<PathBuf>,
116    pub assembly: Option<PathBuf>, // --emit=asm
117    pub llvm_ir: Option<PathBuf>,  // --emit=llvm-ir, llvm-bc is in bytecode
118}
119
120impl CompiledModule {
121    /// Call `emit` function with every artifact type currently compiled
122    pub fn for_each_output(&self, mut emit: impl FnMut(&Path, OutputType)) {
123        if let Some(path) = self.object.as_deref() {
124            emit(path, OutputType::Object);
125        }
126        if let Some(path) = self.bytecode.as_deref() {
127            emit(path, OutputType::Bitcode);
128        }
129        if let Some(path) = self.llvm_ir.as_deref() {
130            emit(path, OutputType::LlvmAssembly);
131        }
132        if let Some(path) = self.assembly.as_deref() {
133            emit(path, OutputType::Assembly);
134        }
135    }
136}
137
138pub(crate) struct CachedModuleCodegen {
139    pub name: String,
140    pub source: WorkProduct,
141}
142
143#[derive(Copy, Clone, Debug, PartialEq, Encodable, Decodable)]
144pub enum ModuleKind {
145    Regular,
146    Metadata,
147    Allocator,
148}
149
150bitflags::bitflags! {
151    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
152    pub struct MemFlags: u8 {
153        const VOLATILE = 1 << 0;
154        const NONTEMPORAL = 1 << 1;
155        const UNALIGNED = 1 << 2;
156    }
157}
158
159#[derive(Clone, Debug, Encodable, Decodable, HashStable)]
160pub struct NativeLib {
161    pub kind: NativeLibKind,
162    pub name: Symbol,
163    pub filename: Option<Symbol>,
164    pub cfg: Option<ast::MetaItemInner>,
165    pub verbatim: bool,
166    pub dll_imports: Vec<cstore::DllImport>,
167}
168
169impl From<&cstore::NativeLib> for NativeLib {
170    fn from(lib: &cstore::NativeLib) -> Self {
171        NativeLib {
172            kind: lib.kind,
173            filename: lib.filename,
174            name: lib.name,
175            cfg: lib.cfg.clone(),
176            verbatim: lib.verbatim.unwrap_or(false),
177            dll_imports: lib.dll_imports.clone(),
178        }
179    }
180}
181
182/// Misc info we load from metadata to persist beyond the tcx.
183///
184/// Note: though `CrateNum` is only meaningful within the same tcx, information within `CrateInfo`
185/// is self-contained. `CrateNum` can be viewed as a unique identifier within a `CrateInfo`, where
186/// `used_crate_source` contains all `CrateSource` of the dependents, and maintains a mapping from
187/// identifiers (`CrateNum`) to `CrateSource`. The other fields map `CrateNum` to the crate's own
188/// additional properties, so that effectively we can retrieve each dependent crate's `CrateSource`
189/// and the corresponding properties without referencing information outside of a `CrateInfo`.
190#[derive(Debug, Encodable, Decodable)]
191pub struct CrateInfo {
192    pub target_cpu: String,
193    pub crate_types: Vec<CrateType>,
194    pub exported_symbols: UnordMap<CrateType, Vec<String>>,
195    pub linked_symbols: FxIndexMap<CrateType, Vec<(String, SymbolExportKind)>>,
196    pub local_crate_name: Symbol,
197    pub compiler_builtins: Option<CrateNum>,
198    pub profiler_runtime: Option<CrateNum>,
199    pub is_no_builtins: FxHashSet<CrateNum>,
200    pub native_libraries: FxIndexMap<CrateNum, Vec<NativeLib>>,
201    pub crate_name: UnordMap<CrateNum, Symbol>,
202    pub used_libraries: Vec<NativeLib>,
203    pub used_crate_source: UnordMap<CrateNum, Arc<CrateSource>>,
204    pub used_crates: Vec<CrateNum>,
205    pub dependency_formats: Arc<Dependencies>,
206    pub windows_subsystem: Option<String>,
207    pub natvis_debugger_visualizers: BTreeSet<DebuggerVisualizerFile>,
208    pub lint_levels: CodegenLintLevels,
209}
210
211#[derive(Encodable, Decodable)]
212pub struct CodegenResults {
213    pub modules: Vec<CompiledModule>,
214    pub allocator_module: Option<CompiledModule>,
215    pub metadata_module: Option<CompiledModule>,
216    pub metadata: rustc_metadata::EncodedMetadata,
217    pub crate_info: CrateInfo,
218}
219
220pub enum CodegenErrors {
221    WrongFileType,
222    EmptyVersionNumber,
223    EncodingVersionMismatch { version_array: String, rlink_version: u32 },
224    RustcVersionMismatch { rustc_version: String },
225    CorruptFile,
226}
227
228pub fn provide(providers: &mut Providers) {
229    crate::back::symbol_export::provide(providers);
230    crate::base::provide(providers);
231    crate::target_features::provide(providers);
232    crate::codegen_attrs::provide(providers);
233}
234
235/// Checks if the given filename ends with the `.rcgu.o` extension that `rustc`
236/// uses for the object files it generates.
237pub fn looks_like_rust_object_file(filename: &str) -> bool {
238    let path = Path::new(filename);
239    let ext = path.extension().and_then(|s| s.to_str());
240    if ext != Some(OutputType::Object.extension()) {
241        // The file name does not end with ".o", so it can't be an object file.
242        return false;
243    }
244
245    // Strip the ".o" at the end
246    let ext2 = path.file_stem().and_then(|s| Path::new(s).extension()).and_then(|s| s.to_str());
247
248    // Check if the "inner" extension
249    ext2 == Some(RUST_CGU_EXT)
250}
251
252const RLINK_VERSION: u32 = 1;
253const RLINK_MAGIC: &[u8] = b"rustlink";
254
255impl CodegenResults {
256    pub fn serialize_rlink(
257        sess: &Session,
258        rlink_file: &Path,
259        codegen_results: &CodegenResults,
260        outputs: &OutputFilenames,
261    ) -> Result<usize, io::Error> {
262        let mut encoder = FileEncoder::new(rlink_file)?;
263        encoder.emit_raw_bytes(RLINK_MAGIC);
264        // `emit_raw_bytes` is used to make sure that the version representation does not depend on
265        // Encoder's inner representation of `u32`.
266        encoder.emit_raw_bytes(&RLINK_VERSION.to_be_bytes());
267        encoder.emit_str(sess.cfg_version);
268        Encodable::encode(codegen_results, &mut encoder);
269        Encodable::encode(outputs, &mut encoder);
270        encoder.finish().map_err(|(_path, err)| err)
271    }
272
273    pub fn deserialize_rlink(
274        sess: &Session,
275        data: Vec<u8>,
276    ) -> Result<(Self, OutputFilenames), CodegenErrors> {
277        // The Decodable machinery is not used here because it panics if the input data is invalid
278        // and because its internal representation may change.
279        if !data.starts_with(RLINK_MAGIC) {
280            return Err(CodegenErrors::WrongFileType);
281        }
282        let data = &data[RLINK_MAGIC.len()..];
283        if data.len() < 4 {
284            return Err(CodegenErrors::EmptyVersionNumber);
285        }
286
287        let mut version_array: [u8; 4] = Default::default();
288        version_array.copy_from_slice(&data[..4]);
289        if u32::from_be_bytes(version_array) != RLINK_VERSION {
290            return Err(CodegenErrors::EncodingVersionMismatch {
291                version_array: String::from_utf8_lossy(&version_array).to_string(),
292                rlink_version: RLINK_VERSION,
293            });
294        }
295
296        let Ok(mut decoder) = MemDecoder::new(&data[4..], 0) else {
297            return Err(CodegenErrors::CorruptFile);
298        };
299        let rustc_version = decoder.read_str();
300        if rustc_version != sess.cfg_version {
301            return Err(CodegenErrors::RustcVersionMismatch {
302                rustc_version: rustc_version.to_string(),
303            });
304        }
305
306        let codegen_results = CodegenResults::decode(&mut decoder);
307        let outputs = OutputFilenames::decode(&mut decoder);
308        Ok((codegen_results, outputs))
309    }
310}
311
312/// A list of lint levels used in codegen.
313///
314/// When using `-Z link-only`, we don't have access to the tcx and must work
315/// solely from the `.rlink` file. `Lint`s are defined too early to be encodeable.
316/// Instead, encode exactly the information we need.
317#[derive(Copy, Clone, Debug, Encodable, Decodable)]
318pub struct CodegenLintLevels {
319    linker_messages: (Level, LintLevelSource),
320}
321
322impl CodegenLintLevels {
323    pub fn from_tcx(tcx: TyCtxt<'_>) -> Self {
324        Self { linker_messages: tcx.lint_level_at_node(LINKER_MESSAGES, CRATE_HIR_ID) }
325    }
326}
rustc_codegen_ssa/lib.rs

rustc_codegen_ssa/
lib.rs
