compiler/rustc_codegen_ssa/src/lib.rs

   1 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
   2 #![feature(bool_to_option)]
   3 #![feature(box_patterns)]
   4 #![feature(drain_filter)]
   5 #![feature(try_blocks)]
   6 #![feature(in_band_lifetimes)]
   7 #![feature(nll)]
   8 #![cfg_attr(bootstrap, feature(or_patterns))]
   9 #![feature(associated_type_bounds)]
  10 #![feature(iter_zip)]
  11 #![recursion_limit = "256"]
  12 #![feature(box_syntax)]
  13
  14 //! This crate contains codegen code that is used by all codegen backends (LLVM and others).
  15 //! The backend-agnostic functions of this crate use functions defined in various traits that
  16 //! have to be implemented by each backends.
  17
  18 #[macro_use]
  19 extern crate rustc_macros;
  20 #[macro_use]
  21 extern crate tracing;
  22 #[macro_use]
  23 extern crate rustc_middle;
  24
  25 use rustc_ast as ast;
  26 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
  27 use rustc_data_structures::sync::Lrc;
  28 use rustc_hir::def_id::CrateNum;
  29 use rustc_hir::LangItem;
  30 use rustc_middle::dep_graph::WorkProduct;
  31 use rustc_middle::middle::cstore::{self, CrateSource, LibSource};
  32 use rustc_middle::middle::dependency_format::Dependencies;
  33 use rustc_middle::ty::query::Providers;
  34 use rustc_session::config::{OutputFilenames, OutputType, RUST_CGU_EXT};
  35 use rustc_session::utils::NativeLibKind;
  36 use rustc_span::symbol::Symbol;
  37 use std::path::{Path, PathBuf};
  38
  39 pub mod back;
  40 pub mod base;
  41 pub mod common;
  42 pub mod coverageinfo;
  43 pub mod debuginfo;
  44 pub mod glue;
  45 pub mod meth;
  46 pub mod mir;
  47 pub mod mono_item;
  48 pub mod target_features;
  49 pub mod traits;
  50
  51 pub struct ModuleCodegen<M> {
  52     /// The name of the module. When the crate may be saved between
  53     /// compilations, incremental compilation requires that name be
  54     /// unique amongst **all** crates. Therefore, it should contain
  55     /// something unique to this crate (e.g., a module path) as well
  56     /// as the crate name and disambiguator.
  57     /// We currently generate these names via CodegenUnit::build_cgu_name().
  58     pub name: String,
  59     pub module_llvm: M,
  60     pub kind: ModuleKind,
  61 }
  62
  63 // FIXME(eddyb) maybe include the crate name in this?
  64 pub const METADATA_FILENAME: &str = "lib.rmeta";
  65
  66 impl<M> ModuleCodegen<M> {
  67     pub fn into_compiled_module(
  68         self,
  69         emit_obj: bool,
  70         emit_dwarf_obj: bool,
  71         emit_bc: bool,
  72         outputs: &OutputFilenames,
  73     ) -> CompiledModule {
  74         let object = emit_obj.then(|| outputs.temp_path(OutputType::Object, Some(&self.name)));
  75         let dwarf_object = emit_dwarf_obj.then(|| outputs.temp_path_dwo(Some(&self.name)));
  76         let bytecode = emit_bc.then(|| outputs.temp_path(OutputType::Bitcode, Some(&self.name)));
  77
  78         CompiledModule { name: self.name.clone(), kind: self.kind, object, dwarf_object, bytecode }
  79     }
  80 }
  81
  82 #[derive(Debug, Encodable, Decodable)]
  83 pub struct CompiledModule {
  84     pub name: String,
  85     pub kind: ModuleKind,
  86     pub object: Option<PathBuf>,
  87     pub dwarf_object: Option<PathBuf>,
  88     pub bytecode: Option<PathBuf>,
  89 }
  90
  91 pub struct CachedModuleCodegen {
  92     pub name: String,
  93     pub source: WorkProduct,
  94 }
  95
  96 #[derive(Copy, Clone, Debug, PartialEq, Encodable, Decodable)]
  97 pub enum ModuleKind {
  98     Regular,
  99     Metadata,
 100     Allocator,
 101 }
 102
 103 bitflags::bitflags! {
 104     pub struct MemFlags: u8 {
 105         const VOLATILE = 1 << 0;
 106         const NONTEMPORAL = 1 << 1;
 107         const UNALIGNED = 1 << 2;
 108     }
 109 }
 110
 111 #[derive(Clone, Debug, Encodable, Decodable, HashStable)]
 112 pub struct NativeLib {
 113     pub kind: NativeLibKind,
 114     pub name: Option<Symbol>,
 115     pub cfg: Option<ast::MetaItem>,
 116 }
 117
 118 impl From<&cstore::NativeLib> for NativeLib {
 119     fn from(lib: &cstore::NativeLib) -> Self {
 120         NativeLib { kind: lib.kind, name: lib.name, cfg: lib.cfg.clone() }
 121     }
 122 }
 123
 124 /// Misc info we load from metadata to persist beyond the tcx.
 125 ///
 126 /// Note: though `CrateNum` is only meaningful within the same tcx, information within `CrateInfo`
 127 /// is self-contained. `CrateNum` can be viewed as a unique identifier within a `CrateInfo`, where
 128 /// `used_crate_source` contains all `CrateSource` of the dependents, and maintains a mapping from
 129 /// identifiers (`CrateNum`) to `CrateSource`. The other fields map `CrateNum` to the crate's own
 130 /// additional properties, so that effectively we can retrieve each dependent crate's `CrateSource`
 131 /// and the corresponding properties without referencing information outside of a `CrateInfo`.
 132 #[derive(Debug, Encodable, Decodable)]
 133 pub struct CrateInfo {
 134     pub panic_runtime: Option<CrateNum>,
 135     pub compiler_builtins: Option<CrateNum>,
 136     pub profiler_runtime: Option<CrateNum>,
 137     pub is_no_builtins: FxHashSet<CrateNum>,
 138     pub native_libraries: FxHashMap<CrateNum, Vec<NativeLib>>,
 139     pub crate_name: FxHashMap<CrateNum, String>,
 140     pub used_libraries: Vec<NativeLib>,
 141     pub used_crate_source: FxHashMap<CrateNum, Lrc<CrateSource>>,
 142     pub used_crates_static: Vec<(CrateNum, LibSource)>,
 143     pub used_crates_dynamic: Vec<(CrateNum, LibSource)>,
 144     pub lang_item_to_crate: FxHashMap<LangItem, CrateNum>,
 145     pub missing_lang_items: FxHashMap<CrateNum, Vec<LangItem>>,
 146     pub dependency_formats: Lrc<Dependencies>,
 147 }
 148
 149 #[derive(Encodable, Decodable)]
 150 pub struct CodegenResults {
 151     pub crate_name: Symbol,
 152     pub modules: Vec<CompiledModule>,
 153     pub allocator_module: Option<CompiledModule>,
 154     pub metadata_module: Option<CompiledModule>,
 155     pub metadata: rustc_middle::middle::cstore::EncodedMetadata,
 156     pub windows_subsystem: Option<String>,
 157     pub linker_info: back::linker::LinkerInfo,
 158     pub crate_info: CrateInfo,
 159 }
 160
 161 pub fn provide(providers: &mut Providers) {
 162     crate::back::symbol_export::provide(providers);
 163     crate::base::provide(providers);
 164     crate::target_features::provide(providers);
 165 }
 166
 167 pub fn provide_extern(providers: &mut Providers) {
 168     crate::back::symbol_export::provide_extern(providers);
 169 }
 170
 171 /// Checks if the given filename ends with the `.rcgu.o` extension that `rustc`
 172 /// uses for the object files it generates.
 173 pub fn looks_like_rust_object_file(filename: &str) -> bool {
 174     let path = Path::new(filename);
 175     let ext = path.extension().and_then(|s| s.to_str());
 176     if ext != Some(OutputType::Object.extension()) {
 177         // The file name does not end with ".o", so it can't be an object file.
 178         return false;
 179     }
 180
 181     // Strip the ".o" at the end
 182     let ext2 = path.file_stem().and_then(|s| Path::new(s).extension()).and_then(|s| s.to_str());
 183
 184     // Check if the "inner" extension
 185     ext2 == Some(RUST_CGU_EXT)
 186 }