From 8551566d1e538124e94a6cde985c2bddc547c0cf Mon Sep 17 00:00:00 2001 From: Alex Crichton Date: Sat, 10 Feb 2018 14:28:17 -0800 Subject: [PATCH] rustc: Add a `#[wasm_import_module]` attribute This commit adds a new attribute to the Rust compiler specific to the wasm target (and no other targets). The `#[wasm_import_module]` attribute is used to specify the module that a name is imported from, and is used like so: #[wasm_import_module = "./foo.js"] extern { fn some_js_function(); } Here the import of the symbol `some_js_function` is tagged with the `./foo.js` module in the wasm output file. Wasm-the-format includes two fields on all imports, a module and a field. The field is the symbol name (`some_js_function` above) and the module has historically unconditionally been `"env"`. I'm not sure if this `"env"` convention has asm.js or LLVM roots, but regardless we'd like the ability to configure it! The proposed ES module integration with wasm (aka a wasm module is "just another ES module") requires that the import module of wasm imports is interpreted as an ES module import, meaning that you'll need to encode paths, NPM packages, etc. As a result, we'll need this to be something other than `"env"`! Unfortunately neither our version of LLVM nor LLD supports custom import modules (aka anything not `"env"`). My hope is that by the time LLVM 7 is released both will have support, but in the meantime this commit adds some primitive encoding/decoding of wasm files to the compiler. This way rustc postprocesses the wasm module that LLVM emits to ensure it's got all the imports we'd like to have in it. Eventually I'd ideally like to unconditionally require this attribute to be placed on all `extern { ... }` blocks. For now though it seemed prudent to add it as an unstable attribute, so for now it's not required (as that'd force usage of a feature gate). Hopefully it doesn't take too long to "stabilize" this! cc rust-lang-nursery/rust-wasm#29 --- src/librustc/dep_graph/dep_node.rs | 4 + src/librustc/hir/check_attr.rs | 27 ++- src/librustc/ich/impls_cstore.rs | 7 +- src/librustc/middle/cstore.rs | 6 + src/librustc/ty/maps/config.rs | 18 ++ src/librustc/ty/maps/mod.rs | 9 +- src/librustc/ty/maps/plumbing.rs | 5 + src/librustc_metadata/creader.rs | 20 +- src/librustc_metadata/cstore.rs | 6 +- src/librustc_metadata/cstore_impl.rs | 22 +- src/librustc_metadata/decoder.rs | 10 +- src/librustc_metadata/encoder.rs | 12 +- src/librustc_metadata/foreign_modules.rs | 48 ++++ src/librustc_metadata/lib.rs | 1 + src/librustc_metadata/native_libs.rs | 7 +- src/librustc_metadata/schema.rs | 3 +- src/librustc_trans/attributes.rs | 47 ++++ src/librustc_trans/back/link.rs | 5 + src/librustc_trans/back/wasm.rs | 213 ++++++++++++++++++ src/librustc_trans/base.rs | 63 +++++- src/librustc_trans/lib.rs | 4 + src/libsyntax/feature_gate.rs | 7 + .../ui/feature-gate-wasm_import_module.rs | 15 ++ .../ui/feature-gate-wasm_import_module.stderr | 11 + src/test/ui/wasm-import-module.rs | 20 ++ src/test/ui/wasm-import-module.stderr | 14 ++ 26 files changed, 559 insertions(+), 45 deletions(-) create mode 100644 src/librustc_metadata/foreign_modules.rs create mode 100644 src/librustc_trans/back/wasm.rs create mode 100644 src/test/ui/feature-gate-wasm_import_module.rs create mode 100644 src/test/ui/feature-gate-wasm_import_module.stderr create mode 100644 src/test/ui/wasm-import-module.rs create mode 100644 src/test/ui/wasm-import-module.stderr diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs index 8d7fef90b754e..8e35beef4d403 100644 --- a/src/librustc/dep_graph/dep_node.rs +++ b/src/librustc/dep_graph/dep_node.rs @@ -590,6 +590,7 @@ define_dep_nodes!( <'tcx> [] ImplementationsOfTrait { krate: CrateNum, trait_id: DefId }, [] AllTraitImplementations(CrateNum), + [] DllimportForeignItems(CrateNum), [] IsDllimportForeignItem(DefId), [] IsStaticallyIncludedForeignItem(DefId), [] NativeLibraryKind(DefId), @@ -648,6 +649,9 @@ define_dep_nodes!( <'tcx> [] GetSymbolExportLevel(DefId), [input] Features, + + [] WasmImportModuleMap(CrateNum), + [] ForeignModules(CrateNum), ); trait DepNodeParams<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> : fmt::Debug { diff --git a/src/librustc/hir/check_attr.rs b/src/librustc/hir/check_attr.rs index d7194e9c2cabb..2db672968c7a6 100644 --- a/src/librustc/hir/check_attr.rs +++ b/src/librustc/hir/check_attr.rs @@ -25,6 +25,7 @@ enum Target { Struct, Union, Enum, + ForeignMod, Other, } @@ -35,6 +36,7 @@ impl Target { hir::ItemStruct(..) => Target::Struct, hir::ItemUnion(..) => Target::Union, hir::ItemEnum(..) => Target::Enum, + hir::ItemForeignMod(..) => Target::ForeignMod, _ => Target::Other, } } @@ -55,14 +57,33 @@ impl<'a, 'tcx> CheckAttrVisitor<'a, 'tcx> { .emit(); } + let mut has_wasm_import_module = false; for attr in &item.attrs { - if let Some(name) = attr.name() { - if name == "inline" { - self.check_inline(attr, item, target) + if attr.check_name("inline") { + self.check_inline(attr, item, target) + } else if attr.check_name("wasm_import_module") { + has_wasm_import_module = true; + if attr.value_str().is_none() { + self.tcx.sess.span_err(attr.span, "\ + must be of the form #[wasm_import_module = \"...\"]"); + } + if target != Target::ForeignMod { + self.tcx.sess.span_err(attr.span, "\ + must only be attached to foreign modules"); } } } + if target == Target::ForeignMod && + !has_wasm_import_module && + self.tcx.sess.target.target.arch == "wasm32" && + false // FIXME: eventually enable this warning when stable + { + self.tcx.sess.span_warn(item.span, "\ + must have a #[wasm_import_module = \"...\"] attribute, this \ + will become a hard error before too long"); + } + self.check_repr(item, target); } diff --git a/src/librustc/ich/impls_cstore.rs b/src/librustc/ich/impls_cstore.rs index 18a02ff5c5882..0071850e1052b 100644 --- a/src/librustc/ich/impls_cstore.rs +++ b/src/librustc/ich/impls_cstore.rs @@ -33,7 +33,12 @@ impl_stable_hash_for!(struct middle::cstore::NativeLibrary { kind, name, cfg, - foreign_items + foreign_module +}); + +impl_stable_hash_for!(struct middle::cstore::ForeignModule { + foreign_items, + def_id }); impl_stable_hash_for!(enum middle::cstore::LinkagePreference { diff --git a/src/librustc/middle/cstore.rs b/src/librustc/middle/cstore.rs index 3c451d7ae46a1..add9b621596b6 100644 --- a/src/librustc/middle/cstore.rs +++ b/src/librustc/middle/cstore.rs @@ -132,7 +132,13 @@ pub struct NativeLibrary { pub kind: NativeLibraryKind, pub name: Symbol, pub cfg: Option, + pub foreign_module: Option, +} + +#[derive(Clone, Hash, RustcEncodable, RustcDecodable)] +pub struct ForeignModule { pub foreign_items: Vec, + pub def_id: DefId, } pub enum LoadedMacro { diff --git a/src/librustc/ty/maps/config.rs b/src/librustc/ty/maps/config.rs index dbfe7770bbde0..71e51fa4c7551 100644 --- a/src/librustc/ty/maps/config.rs +++ b/src/librustc/ty/maps/config.rs @@ -418,6 +418,12 @@ impl<'tcx> QueryDescription<'tcx> for queries::native_libraries<'tcx> { } } +impl<'tcx> QueryDescription<'tcx> for queries::foreign_modules<'tcx> { + fn describe(_tcx: TyCtxt, _: CrateNum) -> String { + format!("looking up the foreign modules of a linked crate") + } +} + impl<'tcx> QueryDescription<'tcx> for queries::plugin_registrar_fn<'tcx> { fn describe(_tcx: TyCtxt, _: CrateNum) -> String { format!("looking up the plugin registrar for a crate") @@ -681,6 +687,18 @@ impl<'tcx> QueryDescription<'tcx> for queries::generics_of<'tcx> { } } +impl<'tcx> QueryDescription<'tcx> for queries::wasm_import_module_map<'tcx> { + fn describe(_tcx: TyCtxt, _: CrateNum) -> String { + format!("wasm import module map") + } +} + +impl<'tcx> QueryDescription<'tcx> for queries::dllimport_foreign_items<'tcx> { + fn describe(_tcx: TyCtxt, _: CrateNum) -> String { + format!("wasm import module map") + } +} + macro_rules! impl_disk_cacheable_query( ($query_name:ident, |$key:tt| $cond:expr) => { impl<'tcx> QueryDescription<'tcx> for queries::$query_name<'tcx> { diff --git a/src/librustc/ty/maps/mod.rs b/src/librustc/ty/maps/mod.rs index 7d726d2e3cd5d..a011d8c12a7f3 100644 --- a/src/librustc/ty/maps/mod.rs +++ b/src/librustc/ty/maps/mod.rs @@ -18,7 +18,7 @@ use infer::canonical::{Canonical, QueryResult}; use lint; use middle::borrowck::BorrowCheckResult; use middle::cstore::{ExternCrate, LinkagePreference, NativeLibrary, - ExternBodyNestedBodies}; + ExternBodyNestedBodies, ForeignModule}; use middle::cstore::{NativeLibraryKind, DepKind, CrateSource, ExternConstBody}; use middle::privacy::AccessLevels; use middle::reachable::ReachableSet; @@ -315,6 +315,9 @@ define_maps! { <'tcx> [] fn native_libraries: NativeLibraries(CrateNum) -> Lrc>, + + [] fn foreign_modules: ForeignModules(CrateNum) -> Lrc>, + [] fn plugin_registrar_fn: PluginRegistrarFn(CrateNum) -> Option, [] fn derive_registrar_fn: DeriveRegistrarFn(CrateNum) -> Option, [] fn crate_disambiguator: CrateDisambiguator(CrateNum) -> CrateDisambiguator, @@ -326,6 +329,8 @@ define_maps! { <'tcx> [] fn all_trait_implementations: AllTraitImplementations(CrateNum) -> Lrc>, + [] fn dllimport_foreign_items: DllimportForeignItems(CrateNum) + -> Lrc>, [] fn is_dllimport_foreign_item: IsDllimportForeignItem(DefId) -> bool, [] fn is_statically_included_foreign_item: IsStaticallyIncludedForeignItem(DefId) -> bool, [] fn native_library_kind: NativeLibraryKind(DefId) @@ -417,6 +422,8 @@ define_maps! { <'tcx> -> usize, [] fn features_query: features_node(CrateNum) -> Lrc, + [] fn wasm_import_module_map: WasmImportModuleMap(CrateNum) + -> Lrc>, } ////////////////////////////////////////////////////////////////////// diff --git a/src/librustc/ty/maps/plumbing.rs b/src/librustc/ty/maps/plumbing.rs index bc7186f781a82..98d98d19b85e0 100644 --- a/src/librustc/ty/maps/plumbing.rs +++ b/src/librustc/ty/maps/plumbing.rs @@ -883,6 +883,9 @@ pub fn force_from_dep_node<'a, 'gcx, 'lcx>(tcx: TyCtxt<'a, 'gcx, 'lcx>, force!(all_trait_implementations, krate!()); } + DepKind::DllimportForeignItems => { + force!(dllimport_foreign_items, krate!()); + } DepKind::IsDllimportForeignItem => { force!(is_dllimport_foreign_item, def_id!()); } @@ -935,6 +938,8 @@ pub fn force_from_dep_node<'a, 'gcx, 'lcx>(tcx: TyCtxt<'a, 'gcx, 'lcx>, DepKind::GetSymbolExportLevel => { force!(symbol_export_level, def_id!()); } DepKind::Features => { force!(features_query, LOCAL_CRATE); } + DepKind::WasmImportModuleMap => { force!(wasm_import_module_map, krate!()); } + DepKind::ForeignModules => { force!(foreign_modules, krate!()); } } true diff --git a/src/librustc_metadata/creader.rs b/src/librustc_metadata/creader.rs index 789ecd0f6136b..31adb8cc1d1db 100644 --- a/src/librustc_metadata/creader.rs +++ b/src/librustc_metadata/creader.rs @@ -12,7 +12,6 @@ use cstore::{self, CStore, CrateSource, MetadataBlob}; use locator::{self, CratePaths}; -use native_libs::relevant_lib; use schema::CrateRoot; use rustc_data_structures::sync::Lrc; @@ -231,7 +230,7 @@ impl<'a> CrateLoader<'a> { .map(|trait_impls| (trait_impls.trait_id, trait_impls.impls)) .collect(); - let mut cmeta = cstore::CrateMetadata { + let cmeta = cstore::CrateMetadata { name, extern_crate: Cell::new(None), def_path_table: Lrc::new(def_path_table), @@ -251,25 +250,8 @@ impl<'a> CrateLoader<'a> { rlib, rmeta, }, - // Initialize this with an empty set. The field is populated below - // after we were able to deserialize its contents. - dllimport_foreign_items: FxHashSet(), }; - let dllimports: FxHashSet<_> = cmeta - .root - .native_libraries - .decode((&cmeta, self.sess)) - .filter(|lib| relevant_lib(self.sess, lib) && - lib.kind == cstore::NativeLibraryKind::NativeUnknown) - .flat_map(|lib| { - assert!(lib.foreign_items.iter().all(|def_id| def_id.krate == cnum)); - lib.foreign_items.into_iter().map(|def_id| def_id.index) - }) - .collect(); - - cmeta.dllimport_foreign_items = dllimports; - let cmeta = Lrc::new(cmeta); self.cstore.set_crate_data(cnum, cmeta.clone()); (cnum, cmeta) diff --git a/src/librustc_metadata/cstore.rs b/src/librustc_metadata/cstore.rs index 202efb9276a81..bc9160493fb71 100644 --- a/src/librustc_metadata/cstore.rs +++ b/src/librustc_metadata/cstore.rs @@ -20,7 +20,7 @@ use rustc::middle::cstore::{DepKind, ExternCrate, MetadataLoader}; use rustc::session::{Session, CrateDisambiguator}; use rustc_back::PanicStrategy; use rustc_data_structures::indexed_vec::IndexVec; -use rustc::util::nodemap::{FxHashMap, FxHashSet, NodeMap}; +use rustc::util::nodemap::{FxHashMap, NodeMap}; use std::cell::{RefCell, Cell}; use rustc_data_structures::sync::Lrc; @@ -31,7 +31,7 @@ use syntax_pos; pub use rustc::middle::cstore::{NativeLibrary, NativeLibraryKind, LinkagePreference}; pub use rustc::middle::cstore::NativeLibraryKind::*; -pub use rustc::middle::cstore::{CrateSource, LibSource}; +pub use rustc::middle::cstore::{CrateSource, LibSource, ForeignModule}; pub use cstore_impl::{provide, provide_extern}; @@ -85,8 +85,6 @@ pub struct CrateMetadata { pub source: CrateSource, pub proc_macros: Option)>>, - // Foreign items imported from a dylib (Windows only) - pub dllimport_foreign_items: FxHashSet, } pub struct CStore { diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs index 0b50f5c44962b..98e0d1c123226 100644 --- a/src/librustc_metadata/cstore_impl.rs +++ b/src/librustc_metadata/cstore_impl.rs @@ -12,6 +12,7 @@ use cstore; use encoder; use link_args; use native_libs; +use foreign_modules; use schema; use rustc::ty::maps::QueryConfig; @@ -194,6 +195,7 @@ provide! { <'tcx> tcx, def_id, other, cdata, Lrc::new(reachable_non_generics) } native_libraries => { Lrc::new(cdata.get_native_libraries(tcx.sess)) } + foreign_modules => { Lrc::new(cdata.get_foreign_modules(tcx.sess)) } plugin_registrar_fn => { cdata.root.plugin_registrar_fn.map(|index| { DefId { krate: def_id.krate, index } @@ -221,9 +223,6 @@ provide! { <'tcx> tcx, def_id, other, cdata, Lrc::new(result) } - is_dllimport_foreign_item => { - cdata.is_dllimport_foreign_item(def_id.index) - } visibility => { cdata.get_visibility(def_id.index) } dep_kind => { cdata.dep_kind.get() } crate_name => { cdata.name } @@ -297,13 +296,28 @@ pub fn provide<'tcx>(providers: &mut Providers<'tcx>) { tcx.native_libraries(id.krate) .iter() .filter(|lib| native_libs::relevant_lib(&tcx.sess, lib)) - .find(|l| l.foreign_items.contains(&id)) + .find(|lib| { + let fm_id = match lib.foreign_module { + Some(id) => id, + None => return false, + }; + tcx.foreign_modules(id.krate) + .iter() + .find(|m| m.def_id == fm_id) + .expect("failed to find foreign module") + .foreign_items + .contains(&id) + }) .map(|l| l.kind) }, native_libraries: |tcx, cnum| { assert_eq!(cnum, LOCAL_CRATE); Lrc::new(native_libs::collect(tcx)) }, + foreign_modules: |tcx, cnum| { + assert_eq!(cnum, LOCAL_CRATE); + Lrc::new(foreign_modules::collect(tcx)) + }, link_args: |tcx, cnum| { assert_eq!(cnum, LOCAL_CRATE); Lrc::new(link_args::collect(tcx)) diff --git a/src/librustc_metadata/decoder.rs b/src/librustc_metadata/decoder.rs index f44703b9335e2..e32e585d8ea15 100644 --- a/src/librustc_metadata/decoder.rs +++ b/src/librustc_metadata/decoder.rs @@ -10,7 +10,7 @@ // Decoding metadata from a single crate's metadata -use cstore::{self, CrateMetadata, MetadataBlob, NativeLibrary}; +use cstore::{self, CrateMetadata, MetadataBlob, NativeLibrary, ForeignModule}; use schema::*; use rustc_data_structures::sync::Lrc; @@ -1034,6 +1034,10 @@ impl<'a, 'tcx> CrateMetadata { self.root.native_libraries.decode((self, sess)).collect() } + pub fn get_foreign_modules(&self, sess: &Session) -> Vec { + self.root.foreign_modules.decode((self, sess)).collect() + } + pub fn get_dylib_dependency_formats(&self) -> Vec<(CrateNum, LinkagePreference)> { self.root .dylib_dependency_formats @@ -1096,10 +1100,6 @@ impl<'a, 'tcx> CrateMetadata { } } - pub fn is_dllimport_foreign_item(&self, id: DefIndex) -> bool { - self.dllimport_foreign_items.contains(&id) - } - pub fn fn_sig(&self, id: DefIndex, tcx: TyCtxt<'a, 'tcx, 'tcx>) diff --git a/src/librustc_metadata/encoder.rs b/src/librustc_metadata/encoder.rs index d959482417489..7ccdb781ee8f3 100644 --- a/src/librustc_metadata/encoder.rs +++ b/src/librustc_metadata/encoder.rs @@ -14,7 +14,7 @@ use isolated_encoder::IsolatedEncoder; use schema::*; use rustc::middle::cstore::{LinkMeta, LinkagePreference, NativeLibrary, - EncodedMetadata}; + EncodedMetadata, ForeignModule}; use rustc::hir::def::CtorKind; use rustc::hir::def_id::{CrateNum, CRATE_DEF_INDEX, DefIndex, DefId, LocalDefId, LOCAL_CRATE}; use rustc::hir::map::definitions::DefPathTable; @@ -416,6 +416,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> { ()); let native_lib_bytes = self.position() - i; + let foreign_modules = self.tracked( + IsolatedEncoder::encode_foreign_modules, + ()); + // Encode codemap i = self.position(); let codemap = self.encode_codemap(); @@ -478,6 +482,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> { lang_items, lang_items_missing, native_libraries, + foreign_modules, codemap, def_path_table, impls, @@ -1334,6 +1339,11 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> { self.lazy_seq(used_libraries.iter().cloned()) } + fn encode_foreign_modules(&mut self, _: ()) -> LazySeq { + let foreign_modules = self.tcx.foreign_modules(LOCAL_CRATE); + self.lazy_seq(foreign_modules.iter().cloned()) + } + fn encode_crate_deps(&mut self, _: ()) -> LazySeq { let crates = self.tcx.crates(); diff --git a/src/librustc_metadata/foreign_modules.rs b/src/librustc_metadata/foreign_modules.rs new file mode 100644 index 0000000000000..c44d891b7f39a --- /dev/null +++ b/src/librustc_metadata/foreign_modules.rs @@ -0,0 +1,48 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +use rustc::hir::itemlikevisit::ItemLikeVisitor; +use rustc::hir; +use rustc::middle::cstore::ForeignModule; +use rustc::ty::TyCtxt; + +pub fn collect<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Vec { + let mut collector = Collector { + tcx, + modules: Vec::new(), + }; + tcx.hir.krate().visit_all_item_likes(&mut collector); + return collector.modules +} + +struct Collector<'a, 'tcx: 'a> { + tcx: TyCtxt<'a, 'tcx, 'tcx>, + modules: Vec, +} + +impl<'a, 'tcx> ItemLikeVisitor<'tcx> for Collector<'a, 'tcx> { + fn visit_item(&mut self, it: &'tcx hir::Item) { + let fm = match it.node { + hir::ItemForeignMod(ref fm) => fm, + _ => return, + }; + + let foreign_items = fm.items.iter() + .map(|it| self.tcx.hir.local_def_id(it.id)) + .collect(); + self.modules.push(ForeignModule { + foreign_items, + def_id: self.tcx.hir.local_def_id(it.id), + }); + } + + fn visit_trait_item(&mut self, _it: &'tcx hir::TraitItem) {} + fn visit_impl_item(&mut self, _it: &'tcx hir::ImplItem) {} +} diff --git a/src/librustc_metadata/lib.rs b/src/librustc_metadata/lib.rs index f77c22bd89544..8509966744948 100644 --- a/src/librustc_metadata/lib.rs +++ b/src/librustc_metadata/lib.rs @@ -56,6 +56,7 @@ mod isolated_encoder; mod schema; mod native_libs; mod link_args; +mod foreign_modules; pub mod creader; pub mod cstore; diff --git a/src/librustc_metadata/native_libs.rs b/src/librustc_metadata/native_libs.rs index 2504f8dc251f9..4bb6d8fb87cf5 100644 --- a/src/librustc_metadata/native_libs.rs +++ b/src/librustc_metadata/native_libs.rs @@ -105,14 +105,11 @@ impl<'a, 'tcx> ItemLikeVisitor<'tcx> for Collector<'a, 'tcx> { } else { None }; - let foreign_items = fm.items.iter() - .map(|it| self.tcx.hir.local_def_id(it.id)) - .collect(); let lib = NativeLibrary { name: n, kind, cfg, - foreign_items, + foreign_module: Some(self.tcx.hir.local_def_id(it.id)), }; self.register_native_lib(Some(m.span), lib); } @@ -218,7 +215,7 @@ impl<'a, 'tcx> Collector<'a, 'tcx> { name: Symbol::intern(new_name.unwrap_or(name)), kind: if let Some(k) = kind { k } else { cstore::NativeUnknown }, cfg: None, - foreign_items: Vec::new(), + foreign_module: None, }; self.register_native_lib(None, lib); } diff --git a/src/librustc_metadata/schema.rs b/src/librustc_metadata/schema.rs index 593f08e90bb3b..a23d3d2f9eb20 100644 --- a/src/librustc_metadata/schema.rs +++ b/src/librustc_metadata/schema.rs @@ -15,8 +15,8 @@ use rustc::hir; use rustc::hir::def::{self, CtorKind}; use rustc::hir::def_id::{DefIndex, DefId, CrateNum}; use rustc::ich::StableHashingContext; -use rustc::middle::cstore::{DepKind, LinkagePreference, NativeLibrary}; use rustc::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel}; +use rustc::middle::cstore::{DepKind, LinkagePreference, NativeLibrary, ForeignModule}; use rustc::middle::lang_items; use rustc::mir; use rustc::session::CrateDisambiguator; @@ -200,6 +200,7 @@ pub struct CrateRoot { pub lang_items: LazySeq<(DefIndex, usize)>, pub lang_items_missing: LazySeq, pub native_libraries: LazySeq, + pub foreign_modules: LazySeq, pub codemap: LazySeq, pub def_path_table: Lazy, pub impls: LazySeq, diff --git a/src/librustc_trans/attributes.rs b/src/librustc_trans/attributes.rs index d5ec8d1b55262..1793487440bae 100644 --- a/src/librustc_trans/attributes.rs +++ b/src/librustc_trans/attributes.rs @@ -14,8 +14,10 @@ use std::ffi::{CStr, CString}; use rustc::hir::TransFnAttrFlags; use rustc::hir::def_id::{DefId, LOCAL_CRATE}; use rustc::session::config::Sanitizer; +use rustc::ty::TyCtxt; use rustc::ty::maps::Providers; use rustc_data_structures::sync::Lrc; +use rustc_data_structures::fx::FxHashMap; use llvm::{self, Attribute, ValueRef}; use llvm::AttributePlace::Function; @@ -139,6 +141,20 @@ pub fn from_fn_attrs(cx: &CodegenCx, llfn: ValueRef, id: DefId) { llfn, llvm::AttributePlace::Function, cstr("target-features\0"), &val); } + + // Note that currently the `wasm-import-module` doesn't do anything, but + // eventually LLVM 7 should read this and ferry the appropriate import + // module to the output file. + if cx.tcx.sess.target.target.arch == "wasm32" { + if let Some(module) = wasm_import_module(cx.tcx, id) { + llvm::AddFunctionAttrStringValue( + llfn, + llvm::AttributePlace::Function, + cstr("wasm-import-module\0"), + &module, + ); + } + } } fn cstr(s: &'static str) -> &CStr { @@ -153,4 +169,35 @@ pub fn provide(providers: &mut Providers) { .map(|c| c.to_string()) .collect()) }; + + provide_extern(providers); +} + +pub fn provide_extern(providers: &mut Providers) { + providers.wasm_import_module_map = |tcx, cnum| { + let mut ret = FxHashMap(); + for lib in tcx.foreign_modules(cnum).iter() { + let attrs = tcx.get_attrs(lib.def_id); + let mut module = None; + for attr in attrs.iter().filter(|a| a.check_name("wasm_import_module")) { + module = attr.value_str(); + } + let module = match module { + Some(s) => s, + None => continue, + }; + for id in lib.foreign_items.iter() { + assert_eq!(id.krate, cnum); + ret.insert(id.index, module.to_string()); + } + } + + Lrc::new(ret) + } +} + +fn wasm_import_module(tcx: TyCtxt, id: DefId) -> Option { + tcx.wasm_import_module_map(id.krate) + .get(&id.index) + .map(|s| CString::new(&s[..]).unwrap()) } diff --git a/src/librustc_trans/back/link.rs b/src/librustc_trans/back/link.rs index 867498d0c59e1..4dc72b7f9000d 100644 --- a/src/librustc_trans/back/link.rs +++ b/src/librustc_trans/back/link.rs @@ -8,6 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. +use back::wasm; use cc::windows_registry; use super::archive::{ArchiveBuilder, ArchiveConfig}; use super::bytecode::RLIB_BYTECODE_EXTENSION; @@ -810,6 +811,10 @@ fn link_natively(sess: &Session, Err(e) => sess.fatal(&format!("failed to run dsymutil: {}", e)), } } + + if sess.opts.target_triple == "wasm32-unknown-unknown" { + wasm::rewrite_imports(&out_filename, &trans.crate_info.wasm_imports); + } } fn exec_linker(sess: &Session, cmd: &mut Command, tmpdir: &Path) diff --git a/src/librustc_trans/back/wasm.rs b/src/librustc_trans/back/wasm.rs new file mode 100644 index 0000000000000..32a61bddbe2bf --- /dev/null +++ b/src/librustc_trans/back/wasm.rs @@ -0,0 +1,213 @@ +// Copyright 2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +use std::fs; +use std::path::Path; +use std::str; + +use rustc_data_structures::fx::FxHashMap; +use serialize::leb128; + +// https://webassembly.github.io/spec/core/binary/modules.html#binary-importsec +const WASM_IMPORT_SECTION_ID: u8 = 2; + +const WASM_EXTERNAL_KIND_FUNCTION: u8 = 0; +const WASM_EXTERNAL_KIND_TABLE: u8 = 1; +const WASM_EXTERNAL_KIND_MEMORY: u8 = 2; +const WASM_EXTERNAL_KIND_GLOBAL: u8 = 3; + +/// Rewrite the module imports are listed from in a wasm module given the field +/// name to module name mapping in `import_map`. +/// +/// LLVM 6 which we're using right now doesn't have the ability to configure the +/// module a wasm symbol is import from. Rather all imported symbols come from +/// the bland `"env"` module unconditionally. Furthermore we'd *also* need +/// support in LLD for preserving these import modules, which it unfortunately +/// currently does not. +/// +/// This function is intended as a hack for now where we manually rewrite the +/// wasm output by LLVM to have the correct import modules listed. The +/// `#[wasm_import_module]` attribute in Rust translates to the module that each +/// symbol is imported from, so here we manually go through the wasm file, +/// decode it, rewrite imports, and then rewrite the wasm module. +pub fn rewrite_imports(path: &Path, import_map: &FxHashMap) { + let wasm = fs::read(path).expect("failed to read wasm output"); + let mut ret = WasmEncoder::new(); + ret.data.extend(&wasm[..8]); + + // skip the 8 byte wasm/version header + for (id, raw) in WasmSections(WasmDecoder::new(&wasm[8..])) { + ret.u32(id as u32); + if id == WASM_IMPORT_SECTION_ID { + info!("rewriting import section"); + let data = rewrite_import_section( + &mut WasmDecoder::new(raw), + import_map, + ); + ret.bytes(&data); + } else { + info!("carry forward section {}, {} bytes long", id, raw.len()); + ret.bytes(raw); + } + } + + fs::write(path, &ret.data).expect("failed to write wasm output"); + + fn rewrite_import_section( + wasm: &mut WasmDecoder, + import_map: &FxHashMap, + ) + -> Vec + { + let mut dst = WasmEncoder::new(); + let n = wasm.u32(); + dst.u32(n); + info!("rewriting {} imports", n); + for _ in 0..n { + rewrite_import_entry(wasm, &mut dst, import_map); + } + return dst.data + } + + fn rewrite_import_entry(wasm: &mut WasmDecoder, + dst: &mut WasmEncoder, + import_map: &FxHashMap) { + // More info about the binary format here is available at: + // https://webassembly.github.io/spec/core/binary/modules.html#import-section + // + // Note that you can also find the whole point of existence of this + // function here, where we map the `module` name to a different one if + // we've got one listed. + let module = wasm.str(); + let field = wasm.str(); + let new_module = if module == "env" { + import_map.get(field).map(|s| &**s).unwrap_or(module) + } else { + module + }; + info!("import rewrite ({} => {}) / {}", module, new_module, field); + dst.str(new_module); + dst.str(field); + let kind = wasm.byte(); + dst.byte(kind); + match kind { + WASM_EXTERNAL_KIND_FUNCTION => dst.u32(wasm.u32()), + WASM_EXTERNAL_KIND_TABLE => { + dst.u32(wasm.u32()); // element_type + dst.limits(wasm.limits()); + } + WASM_EXTERNAL_KIND_MEMORY => dst.limits(wasm.limits()), + WASM_EXTERNAL_KIND_GLOBAL => { + dst.u32(wasm.u32()); // content_type + dst.bool(wasm.bool()); // mutable + } + b => panic!("unknown kind: {}", b), + } + } +} + +struct WasmSections<'a>(WasmDecoder<'a>); + +impl<'a> Iterator for WasmSections<'a> { + type Item = (u8, &'a [u8]); + + fn next(&mut self) -> Option<(u8, &'a [u8])> { + if self.0.data.len() == 0 { + return None + } + + // see https://webassembly.github.io/spec/core/binary/modules.html#sections + let id = self.0.byte(); + let section_len = self.0.u32(); + info!("new section {} / {} bytes", id, section_len); + let section = self.0.skip(section_len as usize); + Some((id, section)) + } +} + +struct WasmDecoder<'a> { + data: &'a [u8], +} + +impl<'a> WasmDecoder<'a> { + fn new(data: &'a [u8]) -> WasmDecoder<'a> { + WasmDecoder { data } + } + + fn byte(&mut self) -> u8 { + self.skip(1)[0] + } + + fn u32(&mut self) -> u32 { + let (n, l1) = leb128::read_u32_leb128(self.data); + self.data = &self.data[l1..]; + return n + } + + fn skip(&mut self, amt: usize) -> &'a [u8] { + let (data, rest) = self.data.split_at(amt); + self.data = rest; + data + } + + fn str(&mut self) -> &'a str { + let len = self.u32(); + str::from_utf8(self.skip(len as usize)).unwrap() + } + + fn bool(&mut self) -> bool { + self.byte() == 1 + } + + fn limits(&mut self) -> (u32, Option) { + let has_max = self.bool(); + (self.u32(), if has_max { Some(self.u32()) } else { None }) + } +} + +struct WasmEncoder { + data: Vec, +} + +impl WasmEncoder { + fn new() -> WasmEncoder { + WasmEncoder { data: Vec::new() } + } + + fn u32(&mut self, val: u32) { + let at = self.data.len(); + leb128::write_u32_leb128(&mut self.data, at, val); + } + + fn byte(&mut self, val: u8) { + self.data.push(val); + } + + fn bytes(&mut self, val: &[u8]) { + self.u32(val.len() as u32); + self.data.extend_from_slice(val); + } + + fn str(&mut self, val: &str) { + self.bytes(val.as_bytes()) + } + + fn bool(&mut self, b: bool) { + self.byte(b as u8); + } + + fn limits(&mut self, limits: (u32, Option)) { + self.bool(limits.1.is_some()); + self.u32(limits.0); + if let Some(c) = limits.1 { + self.u32(c); + } + } +} diff --git a/src/librustc_trans/base.rs b/src/librustc_trans/base.rs index 4da082e9d50f1..99c7dd7951d6f 100644 --- a/src/librustc_trans/base.rs +++ b/src/librustc_trans/base.rs @@ -72,6 +72,7 @@ use type_::Type; use type_of::LayoutLlvmExt; use rustc::util::nodemap::{FxHashMap, FxHashSet, DefIdSet}; use CrateInfo; +use rustc_data_structures::sync::Lrc; use std::any::Any; use std::ffi::CString; @@ -1070,8 +1071,20 @@ impl CrateInfo { used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic), used_crates_static: cstore::used_crates(tcx, LinkagePreference::RequireStatic), used_crate_source: FxHashMap(), + wasm_imports: FxHashMap(), }; + + let load_wasm_items = tcx.sess.crate_types.borrow() + .iter() + .any(|c| *c != config::CrateTypeRlib) && + tcx.sess.opts.target_triple == "wasm32-unknown-unknown"; + + if load_wasm_items { + info!("attempting to load all wasm itesm"); + info.load_wasm_imports(tcx, LOCAL_CRATE); + } + for &cnum in tcx.crates().iter() { info.native_libraries.insert(cnum, tcx.native_libraries(cnum)); info.crate_name.insert(cnum, tcx.crate_name(cnum).to_string()); @@ -1091,11 +1104,22 @@ impl CrateInfo { if tcx.is_no_builtins(cnum) { info.is_no_builtins.insert(cnum); } + if load_wasm_items { + info.load_wasm_imports(tcx, cnum); + } } - return info } + + fn load_wasm_imports(&mut self, tcx: TyCtxt, cnum: CrateNum) { + for (&index, module) in tcx.wasm_import_module_map(cnum).iter() { + let id = DefId { krate: cnum, index }; + let instance = Instance::mono(tcx, id); + let import_name = tcx.symbol_name(instance); + self.wasm_imports.insert(import_name.to_string(), module.clone()); + } + } } fn is_translated_item(tcx: TyCtxt, id: DefId) -> bool { @@ -1223,6 +1247,43 @@ pub fn provide(providers: &mut Providers) { .expect(&format!("failed to find cgu with name {:?}", name)) }; providers.compile_codegen_unit = compile_codegen_unit; + + provide_extern(providers); +} + +pub fn provide_extern(providers: &mut Providers) { + providers.dllimport_foreign_items = |tcx, krate| { + let module_map = tcx.foreign_modules(krate); + let module_map = module_map.iter() + .map(|lib| (lib.def_id, lib)) + .collect::>(); + + let dllimports = tcx.native_libraries(krate) + .iter() + .filter(|lib| { + if lib.kind != cstore::NativeLibraryKind::NativeUnknown { + return false + } + let cfg = match lib.cfg { + Some(ref cfg) => cfg, + None => return true, + }; + attr::cfg_matches(cfg, &tcx.sess.parse_sess, None) + }) + .filter_map(|lib| lib.foreign_module) + .map(|id| &module_map[&id]) + .flat_map(|module| module.foreign_items.iter().cloned()) + .map(|id| { + assert_eq!(id.krate, krate); + id.index + }) + .collect(); + Lrc::new(dllimports) + }; + + providers.is_dllimport_foreign_item = |tcx, def_id| { + tcx.dllimport_foreign_items(def_id.krate).contains(&def_id.index) + }; } pub fn linkage_to_llvm(linkage: Linkage) -> llvm::Linkage { diff --git a/src/librustc_trans/lib.rs b/src/librustc_trans/lib.rs index 39eb38658fee9..66b5d60154766 100644 --- a/src/librustc_trans/lib.rs +++ b/src/librustc_trans/lib.rs @@ -98,6 +98,7 @@ mod back { pub mod symbol_export; pub mod write; mod rpath; + mod wasm; } mod abi; @@ -213,6 +214,8 @@ impl TransCrate for LlvmTransCrate { fn provide_extern(&self, providers: &mut ty::maps::Providers) { back::symbol_export::provide_extern(providers); + base::provide_extern(providers); + attributes::provide_extern(providers); } fn trans_crate<'a, 'tcx>( @@ -399,6 +402,7 @@ struct CrateInfo { used_crate_source: FxHashMap>, used_crates_static: Vec<(CrateNum, LibSource)>, used_crates_dynamic: Vec<(CrateNum, LibSource)>, + wasm_imports: FxHashMap, } __build_diagnostic_array! { librustc_trans, DIAGNOSTICS } diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs index ec9a15d9f2b44..d41c5613526c8 100644 --- a/src/libsyntax/feature_gate.rs +++ b/src/libsyntax/feature_gate.rs @@ -455,6 +455,9 @@ declare_features! ( // Parentheses in patterns (active, pattern_parentheses, "1.26.0", None, None), + + // The #![wasm_import_module] attribute + (active, wasm_import_module, "1.26.0", None, None), ); declare_features! ( @@ -908,6 +911,10 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG "the `#[no_debug]` attribute was an experimental feature that has been \ deprecated due to lack of demand", cfg_fn!(no_debug))), + ("wasm_import_module", Normal, Gated(Stability::Unstable, + "wasm_import_module", + "experimental attribute", + cfg_fn!(wasm_import_module))), ("omit_gdb_pretty_printer_section", Whitelisted, Gated(Stability::Unstable, "omit_gdb_pretty_printer_section", "the `#[omit_gdb_pretty_printer_section]` \ diff --git a/src/test/ui/feature-gate-wasm_import_module.rs b/src/test/ui/feature-gate-wasm_import_module.rs new file mode 100644 index 0000000000000..c5898a9c12697 --- /dev/null +++ b/src/test/ui/feature-gate-wasm_import_module.rs @@ -0,0 +1,15 @@ +// Copyright 2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#[wasm_import_module = "test"] //~ ERROR: experimental +extern { +} + +fn main() {} diff --git a/src/test/ui/feature-gate-wasm_import_module.stderr b/src/test/ui/feature-gate-wasm_import_module.stderr new file mode 100644 index 0000000000000..9b13199a7e4a3 --- /dev/null +++ b/src/test/ui/feature-gate-wasm_import_module.stderr @@ -0,0 +1,11 @@ +error[E0658]: experimental attribute + --> $DIR/feature-gate-wasm_import_module.rs:11:1 + | +LL | #[wasm_import_module = "test"] //~ ERROR: experimental + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: add #![feature(wasm_import_module)] to the crate attributes to enable + +error: aborting due to previous error + +If you want more information on this error, try using "rustc --explain E0658" diff --git a/src/test/ui/wasm-import-module.rs b/src/test/ui/wasm-import-module.rs new file mode 100644 index 0000000000000..0b743d9e486b6 --- /dev/null +++ b/src/test/ui/wasm-import-module.rs @@ -0,0 +1,20 @@ +// Copyright 2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#![feature(wasm_import_module)] + +#[wasm_import_module] //~ ERROR: must be of the form +extern {} + +#[wasm_import_module = "foo"] //~ ERROR: must only be attached to +fn foo() {} + +fn main() {} + diff --git a/src/test/ui/wasm-import-module.stderr b/src/test/ui/wasm-import-module.stderr new file mode 100644 index 0000000000000..bf301ce5269a7 --- /dev/null +++ b/src/test/ui/wasm-import-module.stderr @@ -0,0 +1,14 @@ +error: must be of the form #[wasm_import_module = "..."] + --> $DIR/wasm-import-module.rs:13:1 + | +LL | #[wasm_import_module] //~ ERROR: must be of the form + | ^^^^^^^^^^^^^^^^^^^^^ + +error: must only be attached to foreign modules + --> $DIR/wasm-import-module.rs:16:1 + | +LL | #[wasm_import_module = "foo"] //~ ERROR: must only be attached to + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 2 previous errors +