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 #![feature(or_patterns)]
   9 #![feature(associated_type_bounds)]
  10 #![recursion_limit = "256"]
  11 #![feature(box_syntax)]
  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 backends.
  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_hir::LangItem;
  29 use rustc_middle::dep_graph::WorkProduct;
  30 use rustc_middle::middle::cstore::{self, CrateSource, LibSource};
  31 use rustc_middle::middle::dependency_format::Dependencies;
  32 use rustc_middle::ty::query::Providers;
  33 use rustc_session::config::{OutputFilenames, OutputType, RUST_CGU_EXT};
  34 use rustc_session::utils::NativeLibKind;
  35 use rustc_span::symbol::Symbol;
  36 use std::path::{Path, PathBuf};
  37
  38 pub mod back;
  39 pub mod base;
  40 pub mod common;
  41 pub mod coverageinfo;
  42 pub mod debuginfo;
  43 pub mod glue;
  44 pub mod meth;
  45 pub mod mir;
  46 pub mod mono_item;
  47 pub mod target_features;
  48 pub mod traits;
  49
  50 pub struct ModuleCodegen<M> {
  51     /// The name of the module. When the crate may be saved between
  52     /// compilations, incremental compilation requires that name be
  53     /// unique amongst **all** crates. Therefore, it should contain
  54     /// something unique to this crate (e.g., a module path) as well
  55     /// as the crate name and disambiguator.
  56     /// We currently generate these names via CodegenUnit::build_cgu_name().
  57     pub name: String,
  58     pub module_llvm: M,
  59     pub kind: ModuleKind,
  60 }
  61
  62 // FIXME(eddyb) maybe include the crate name in this?
  63 pub const METADATA_FILENAME: &str = "lib.rmeta";
  64
  65 impl<M> ModuleCodegen<M> {
  66     pub fn into_compiled_module(
  67         self,
  68         emit_obj: bool,
  69         emit_dwarf_obj: bool,
  70         emit_bc: bool,
  71         outputs: &OutputFilenames,
  72     ) -> CompiledModule {
  73         let object = emit_obj.then(|| outputs.temp_path(OutputType::Object, Some(&self.name)));
  74         let dwarf_object = emit_dwarf_obj.then(|| outputs.temp_path_dwo(Some(&self.name)));
  75         let bytecode = emit_bc.then(|| outputs.temp_path(OutputType::Bitcode, Some(&self.name)));
  76
  77         CompiledModule { name: self.name.clone(), kind: self.kind, object, dwarf_object, bytecode }
  78     }
  79 }
  80
  81 #[derive(Debug, Encodable, Decodable)]
  82 pub struct CompiledModule {
  83     pub name: String,
  84     pub kind: ModuleKind,
  85     pub object: Option<PathBuf>,
  86     pub dwarf_object: Option<PathBuf>,
  87     pub bytecode: Option<PathBuf>,
  88 }
  89
  90 pub struct CachedModuleCodegen {
  91     pub name: String,
  92     pub source: WorkProduct,
  93 }
  94
  95 #[derive(Copy, Clone, Debug, PartialEq, Encodable, Decodable)]
  96 pub enum ModuleKind {
  97     Regular,
  98     Metadata,
  99     Allocator,
 100 }
 101
 102 bitflags::bitflags! {
 103     pub struct MemFlags: u8 {
 104         const VOLATILE = 1 << 0;
 105         const NONTEMPORAL = 1 << 1;
 106         const UNALIGNED = 1 << 2;
 107     }
 108 }
 109
 110 #[derive(Clone, Debug, Encodable, Decodable, HashStable)]
 111 pub struct NativeLib {
 112     pub kind: NativeLibKind,
 113     pub name: Option<Symbol>,
 114     pub cfg: Option<ast::MetaItem>,
 115 }
 116
 117 impl From<&cstore::NativeLib> for NativeLib {
 118     fn from(lib: &cstore::NativeLib) -> Self {
 119         NativeLib { kind: lib.kind, name: lib.name, cfg: lib.cfg.clone() }
 120     }
 121 }
 122
 123 /// Misc info we load from metadata to persist beyond the tcx.
 124 ///
 125 /// Note: though `CrateNum` is only meaningful within the same tcx, information within `CrateInfo`
 126 /// is self-contained. `CrateNum` can be viewed as a unique identifier within a `CrateInfo`, where
 127 /// `used_crate_source` contains all `CrateSource` of the dependents, and maintains a mapping from
 128 /// identifiers (`CrateNum`) to `CrateSource`. The other fields map `CrateNum` to the crate's own
 129 /// additional properties, so that effectively we can retrieve each dependent crate's `CrateSource`
 130 /// and the corresponding properties without referencing information outside of a `CrateInfo`.
 131 #[derive(Debug, Encodable, Decodable)]
 132 pub struct CrateInfo {
 133     pub panic_runtime: Option<CrateNum>,
 134     pub compiler_builtins: Option<CrateNum>,
 135     pub profiler_runtime: Option<CrateNum>,
 136     pub is_no_builtins: FxHashSet<CrateNum>,
 137     pub native_libraries: FxHashMap<CrateNum, Vec<NativeLib>>,
 138     pub crate_name: FxHashMap<CrateNum, String>,
 139     pub used_libraries: Vec<NativeLib>,
 140     pub link_args: Lrc<Vec<String>>,
 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 }