diff options
| -rw-r--r-- | src/librustc_codegen_llvm/back/link.rs | 1 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/back/wasm.rs | 126 | ||||
| -rw-r--r-- | src/librustc_codegen_ssa/base.rs | 24 | ||||
| -rw-r--r-- | src/librustc_codegen_ssa/lib.rs | 1 | ||||
| m--------- | src/llvm-project | 0 |
5 files changed, 1 insertions, 151 deletions
diff --git a/src/librustc_codegen_llvm/back/link.rs b/src/librustc_codegen_llvm/back/link.rs index 819f7f94102..6c175ff4247 100644 --- a/src/librustc_codegen_llvm/back/link.rs +++ b/src/librustc_codegen_llvm/back/link.rs @@ -698,7 +698,6 @@ fn link_natively(sess: &Session, } if sess.opts.target_triple.triple() == "wasm32-unknown-unknown" { - wasm::rewrite_imports(&out_filename, &codegen_results.crate_info.wasm_imports); wasm::add_producer_section( &out_filename, &sess.edition().to_string(), diff --git a/src/librustc_codegen_llvm/back/wasm.rs b/src/librustc_codegen_llvm/back/wasm.rs index e1d3351d3de..f90bb89fbe8 100644 --- a/src/librustc_codegen_llvm/back/wasm.rs +++ b/src/librustc_codegen_llvm/back/wasm.rs @@ -2,116 +2,11 @@ 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_CUSTOM_SECTION_ID: u8 = 0; -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 -/// `#[link(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. -/// -/// Support for this was added to LLVM in -/// https://github.com/llvm-mirror/llvm/commit/0f32e1365, although support still -/// needs to be added, tracked at https://bugs.llvm.org/show_bug.cgi?id=37168 -pub fn rewrite_imports(path: &Path, import_map: &FxHashMap<String, String>) { - if import_map.is_empty() { - return - } - - 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.byte(id); - 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<String, String>, - ) - -> Vec<u8> - { - 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<String, String>) { - // 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.byte(wasm.byte()); // element_type - dst.limits(wasm.limits()); - } - WASM_EXTERNAL_KIND_MEMORY => dst.limits(wasm.limits()), - WASM_EXTERNAL_KIND_GLOBAL => { - dst.byte(wasm.byte()); // content_type - dst.bool(wasm.bool()); // mutable - } - b => panic!("unknown kind: {}", b), - } - } -} - /// Adds or augment the existing `producers` section to encode information about /// the Rust compiler used to produce the wasm file. pub fn add_producer_section( @@ -266,15 +161,6 @@ impl<'a> WasmDecoder<'a> { 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<u32>) { - let has_max = self.bool(); - (self.u32(), if has_max { Some(self.u32()) } else { None }) - } } struct WasmEncoder { @@ -302,16 +188,4 @@ impl WasmEncoder { 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<u32>)) { - self.bool(limits.1.is_some()); - self.u32(limits.0); - if let Some(c) = limits.1 { - self.u32(c); - } - } } diff --git a/src/librustc_codegen_ssa/base.rs b/src/librustc_codegen_ssa/base.rs index fad41a11a82..39ce15e4772 100644 --- a/src/librustc_codegen_ssa/base.rs +++ b/src/librustc_codegen_ssa/base.rs @@ -16,7 +16,7 @@ use crate::{ModuleCodegen, ModuleKind, CachedModuleCodegen}; use rustc::dep_graph::cgu_reuse_tracker::CguReuse; -use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE}; +use rustc::hir::def_id::{DefId, LOCAL_CRATE}; use rustc::middle::lang_items::StartFnLangItem; use rustc::middle::weak_lang_items; use rustc::mir::mono::{Stats, CodegenUnitNameBuilder}; @@ -816,21 +816,11 @@ impl CrateInfo { used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic), used_crates_static: cstore::used_crates(tcx, LinkagePreference::RequireStatic), used_crate_source: Default::default(), - wasm_imports: Default::default(), lang_item_to_crate: Default::default(), missing_lang_items: Default::default(), }; let lang_items = tcx.lang_items(); - let load_wasm_items = tcx.sess.crate_types.borrow() - .iter() - .any(|c| *c != config::CrateType::Rlib) && - tcx.sess.opts.target_triple.triple() == "wasm32-unknown-unknown"; - - if load_wasm_items { - info.load_wasm_imports(tcx, LOCAL_CRATE); - } - let crates = tcx.crates(); let n_crates = crates.len(); @@ -858,9 +848,6 @@ impl CrateInfo { if tcx.is_no_builtins(cnum) { info.is_no_builtins.insert(cnum); } - if load_wasm_items { - info.load_wasm_imports(tcx, cnum); - } let missing = tcx.missing_lang_items(cnum); for &item in missing.iter() { if let Ok(id) = lang_items.require(item) { @@ -879,15 +866,6 @@ impl CrateInfo { return info } - - fn load_wasm_imports(&mut self, tcx: TyCtxt<'_, '_, '_>, cnum: CrateNum) { - self.wasm_imports.extend(tcx.wasm_import_module_map(cnum).iter().map(|(&id, module)| { - let instance = Instance::mono(tcx, id); - let import_name = tcx.symbol_name(instance); - - (import_name.to_string(), module.clone()) - })); - } } fn is_codegened_item(tcx: TyCtxt<'_, '_, '_>, id: DefId) -> bool { diff --git a/src/librustc_codegen_ssa/lib.rs b/src/librustc_codegen_ssa/lib.rs index 92fa2766f87..f38b22aa041 100644 --- a/src/librustc_codegen_ssa/lib.rs +++ b/src/librustc_codegen_ssa/lib.rs @@ -138,7 +138,6 @@ pub struct CrateInfo { pub used_crate_source: FxHashMap<CrateNum, Lrc<CrateSource>>, pub used_crates_static: Vec<(CrateNum, LibSource)>, pub used_crates_dynamic: Vec<(CrateNum, LibSource)>, - pub wasm_imports: FxHashMap<String, String>, pub lang_item_to_crate: FxHashMap<LangItem, CrateNum>, pub missing_lang_items: FxHashMap<CrateNum, Vec<LangItem>>, } diff --git a/src/llvm-project b/src/llvm-project -Subproject 73a75d35b9776d56160fa3200aca4a970ae49b6 +Subproject 38ad31bde8ff681d862dc0f96930a5dd9b7a472 |