compiler/rustc_codegen_ssa/src/lib.rs

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