diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/doc/rustc/src/codegen-options/index.md | 46 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/back/archive.rs | 6 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/back/bytecode.rs | 141 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/back/lto.rs | 48 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/back/write.rs | 66 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/lib.rs | 1 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/llvm/ffi.rs | 5 | ||||
| -rw-r--r-- | src/librustc_codegen_ssa/back/link.rs | 22 | ||||
| -rw-r--r-- | src/librustc_codegen_ssa/back/write.rs | 32 | ||||
| -rw-r--r-- | src/librustc_codegen_ssa/lib.rs | 18 | ||||
| -rw-r--r-- | src/librustc_incremental/persist/work_product.rs | 1 | ||||
| -rw-r--r-- | src/librustc_query_system/dep_graph/graph.rs | 1 | ||||
| m--------- | src/llvm-project | 0 | ||||
| -rw-r--r-- | src/rustllvm/PassWrapper.cpp | 28 | ||||
| -rw-r--r-- | src/test/ui/auxiliary/lto-rustc-loads-linker-plugin.rs | 6 | ||||
| -rw-r--r-- | src/test/ui/lto-duplicate-symbols.stderr | 2 | ||||
| -rw-r--r-- | src/test/ui/lto-rustc-loads-linker-plugin.rs | 17 | ||||
| -rw-r--r-- | src/test/ui/lto-thin-rustc-loads-linker-plugin.rs | 13 |
18 files changed, 188 insertions, 265 deletions
diff --git a/src/doc/rustc/src/codegen-options/index.md b/src/doc/rustc/src/codegen-options/index.md index dc5d797ebbc..6b31430f7ec 100644 --- a/src/doc/rustc/src/codegen-options/index.md +++ b/src/doc/rustc/src/codegen-options/index.md @@ -7,6 +7,32 @@ a version of this list for your exact compiler by running `rustc -C help`. This option is deprecated and does nothing. +## bitcode-in-rlib + +This flag controls whether or not the compiler puts LLVM bitcode into generated +rlibs. It takes one of the following values: + +* `y`, `yes`, `on`, or no value: put bitcode in rlibs (the default). +* `n`, `no`, or `off`: omit bitcode from rlibs. + +LLVM bitcode is only needed when link-time optimization (LTO) is being +performed, but it is enabled by default for backwards compatibility reasons. + +The use of `-C bitcode-in-rlib=no` can significantly improve compile times and +reduce generated file sizes. For these reasons, Cargo uses `-C +bitcode-in-rlib=no` whenever possible. Likewise, if you are building directly +with `rustc` we recommend using `-C bitcode-in-rlib=no` whenever you are not +using LTO. + +If combined with `-C lto`, `-C bitcode-in-rlib=no` will cause `rustc` to abort +at start-up, because the combination is invalid. + +> **Note**: the implementation of this flag today is to enable the +> `-Zembed-bitcode` option. When bitcode is embedded into an rlib then all +> object files within the rlib will have a special section (typically named +> `.llvmbc`, depends on the platform though) which contains LLVM bytecode. This +> section of the object file will not appear in the final linked artifact. + ## code-model This option lets you choose which code model to use. @@ -422,26 +448,6 @@ This also supports the feature `+crt-static` and `-crt-static` to control Each target and [`target-cpu`](#target-cpu) has a default set of enabled features. -## bitcode-in-rlib - -This flag controls whether or not the compiler puts compressed LLVM bitcode -into generated rlibs. It takes one of the following values: - -* `y`, `yes`, `on`, or no value: put bitcode in rlibs (the default). -* `n`, `no`, or `off`: omit bitcode from rlibs. - -LLVM bitcode is only needed when link-time optimization (LTO) is being -performed, but it is enabled by default for backwards compatibility reasons. - -The use of `-C bitcode-in-rlib=no` can significantly improve compile times and -reduce generated file sizes. For these reasons, Cargo uses `-C -bitcode-in-rlib=no` whenever possible. Likewise, if you are building directly -with `rustc` we recommend using `-C bitcode-in-rlib=no` whenever you are not -using LTO. - -If combined with `-C lto`, `-C bitcode-in-rlib=no` will cause `rustc` to abort -at start-up, because the combination is invalid. - [option-emit]: ../command-line-arguments.md#option-emit [option-o-optimize]: ../command-line-arguments.md#option-o-optimize [profile-guided optimization]: ../profile-guided-optimization.md diff --git a/src/librustc_codegen_llvm/back/archive.rs b/src/librustc_codegen_llvm/back/archive.rs index f1fe40d919e..a115a1e9516 100644 --- a/src/librustc_codegen_llvm/back/archive.rs +++ b/src/librustc_codegen_llvm/back/archive.rs @@ -10,7 +10,7 @@ use std::str; use crate::llvm::archive_ro::{ArchiveRO, Child}; use crate::llvm::{self, ArchiveKind}; use rustc_codegen_ssa::back::archive::{find_library, ArchiveBuilder}; -use rustc_codegen_ssa::{looks_like_rust_object_file, METADATA_FILENAME, RLIB_BYTECODE_EXTENSION}; +use rustc_codegen_ssa::{looks_like_rust_object_file, METADATA_FILENAME}; use rustc_session::Session; use rustc_span::symbol::Symbol; @@ -129,8 +129,8 @@ impl<'a> ArchiveBuilder<'a> for LlvmArchiveBuilder<'a> { let obj_start = name.to_owned(); self.add_archive(rlib, move |fname: &str| { - // Ignore bytecode/metadata files, no matter the name. - if fname.ends_with(RLIB_BYTECODE_EXTENSION) || fname == METADATA_FILENAME { + // Ignore metadata files, no matter the name. + if fname == METADATA_FILENAME { return true; } diff --git a/src/librustc_codegen_llvm/back/bytecode.rs b/src/librustc_codegen_llvm/back/bytecode.rs deleted file mode 100644 index 0c8ce39132a..00000000000 --- a/src/librustc_codegen_llvm/back/bytecode.rs +++ /dev/null @@ -1,141 +0,0 @@ -//! Management of the encoding of LLVM bytecode into rlibs -//! -//! This module contains the management of encoding LLVM bytecode into rlibs, -//! primarily for the usage in LTO situations. Currently the compiler will -//! unconditionally encode LLVM-IR into rlibs regardless of what's happening -//! elsewhere, so we currently compress the bytecode via deflate to avoid taking -//! up too much space on disk. -//! -//! After compressing the bytecode we then have the rest of the format to -//! basically deal with various bugs in various archive implementations. The -//! format currently is: -//! -//! RLIB LLVM-BYTECODE OBJECT LAYOUT -//! Version 2 -//! Bytes Data -//! 0..10 "RUST_OBJECT" encoded in ASCII -//! 11..14 format version as little-endian u32 -//! 15..19 the length of the module identifier string -//! 20..n the module identifier string -//! n..n+8 size in bytes of deflate compressed LLVM bitcode as -//! little-endian u64 -//! n+9.. compressed LLVM bitcode -//! ? maybe a byte to make this whole thing even length - -use std::io::{Read, Write}; -use std::ptr; -use std::str; - -use flate2::read::DeflateDecoder; -use flate2::write::DeflateEncoder; -use flate2::Compression; - -// This is the "magic number" expected at the beginning of a LLVM bytecode -// object in an rlib. -pub const RLIB_BYTECODE_OBJECT_MAGIC: &[u8] = b"RUST_OBJECT"; - -// The version number this compiler will write to bytecode objects in rlibs -pub const RLIB_BYTECODE_OBJECT_VERSION: u8 = 2; - -pub fn encode(identifier: &str, bytecode: &[u8]) -> Vec<u8> { - let mut encoded = Vec::new(); - - // Start off with the magic string - encoded.extend_from_slice(RLIB_BYTECODE_OBJECT_MAGIC); - - // Next up is the version - encoded.extend_from_slice(&[RLIB_BYTECODE_OBJECT_VERSION, 0, 0, 0]); - - // Next is the LLVM module identifier length + contents - let identifier_len = identifier.len(); - encoded.extend_from_slice(&[ - (identifier_len >> 0) as u8, - (identifier_len >> 8) as u8, - (identifier_len >> 16) as u8, - (identifier_len >> 24) as u8, - ]); - encoded.extend_from_slice(identifier.as_bytes()); - - // Next is the LLVM module deflate compressed, prefixed with its length. We - // don't know its length yet, so fill in 0s - let deflated_size_pos = encoded.len(); - encoded.extend_from_slice(&[0, 0, 0, 0, 0, 0, 0, 0]); - - let before = encoded.len(); - DeflateEncoder::new(&mut encoded, Compression::fast()).write_all(bytecode).unwrap(); - let after = encoded.len(); - - // Fill in the length we reserved space for before - let bytecode_len = (after - before) as u64; - encoded[deflated_size_pos + 0] = (bytecode_len >> 0) as u8; - encoded[deflated_size_pos + 1] = (bytecode_len >> 8) as u8; - encoded[deflated_size_pos + 2] = (bytecode_len >> 16) as u8; - encoded[deflated_size_pos + 3] = (bytecode_len >> 24) as u8; - encoded[deflated_size_pos + 4] = (bytecode_len >> 32) as u8; - encoded[deflated_size_pos + 5] = (bytecode_len >> 40) as u8; - encoded[deflated_size_pos + 6] = (bytecode_len >> 48) as u8; - encoded[deflated_size_pos + 7] = (bytecode_len >> 56) as u8; - - // If the number of bytes written to the object so far is odd, add a - // padding byte to make it even. This works around a crash bug in LLDB - // (see issue #15950) - if encoded.len() % 2 == 1 { - encoded.push(0); - } - - encoded -} - -pub struct DecodedBytecode<'a> { - identifier: &'a str, - encoded_bytecode: &'a [u8], -} - -impl<'a> DecodedBytecode<'a> { - pub fn new(data: &'a [u8]) -> Result<DecodedBytecode<'a>, &'static str> { - if !data.starts_with(RLIB_BYTECODE_OBJECT_MAGIC) { - return Err("magic bytecode prefix not found"); - } - let data = &data[RLIB_BYTECODE_OBJECT_MAGIC.len()..]; - if !data.starts_with(&[RLIB_BYTECODE_OBJECT_VERSION, 0, 0, 0]) { - return Err("wrong version prefix found in bytecode"); - } - let data = &data[4..]; - if data.len() < 4 { - return Err("bytecode corrupted"); - } - let identifier_len = - unsafe { u32::from_le(ptr::read_unaligned(data.as_ptr() as *const u32)) as usize }; - let data = &data[4..]; - if data.len() < identifier_len { - return Err("bytecode corrupted"); - } - let identifier = match str::from_utf8(&data[..identifier_len]) { - Ok(s) => s, - Err(_) => return Err("bytecode corrupted"), - }; - let data = &data[identifier_len..]; - if data.len() < 8 { - return Err("bytecode corrupted"); - } - let bytecode_len = - unsafe { u64::from_le(ptr::read_unaligned(data.as_ptr() as *const u64)) as usize }; - let data = &data[8..]; - if data.len() < bytecode_len { - return Err("bytecode corrupted"); - } - let encoded_bytecode = &data[..bytecode_len]; - - Ok(DecodedBytecode { identifier, encoded_bytecode }) - } - - pub fn bytecode(&self) -> Vec<u8> { - let mut data = Vec::new(); - DeflateDecoder::new(self.encoded_bytecode).read_to_end(&mut data).unwrap(); - data - } - - pub fn identifier(&self) -> &'a str { - self.identifier - } -} diff --git a/src/librustc_codegen_llvm/back/lto.rs b/src/librustc_codegen_llvm/back/lto.rs index 7292492a0c0..e65bdbe171b 100644 --- a/src/librustc_codegen_llvm/back/lto.rs +++ b/src/librustc_codegen_llvm/back/lto.rs @@ -1,4 +1,3 @@ -use crate::back::bytecode::DecodedBytecode; use crate::back::write::{ self, save_temp_bitcode, to_llvm_opt_settings, with_llvm_pmb, DiagnosticHandlers, }; @@ -10,7 +9,7 @@ use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModul use rustc_codegen_ssa::back::symbol_export; use rustc_codegen_ssa::back::write::{CodegenContext, FatLTOInput, ModuleConfig}; use rustc_codegen_ssa::traits::*; -use rustc_codegen_ssa::{ModuleCodegen, ModuleKind, RLIB_BYTECODE_EXTENSION}; +use rustc_codegen_ssa::{looks_like_rust_object_file, ModuleCodegen, ModuleKind}; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_errors::{FatalError, Handler}; use rustc_hir::def_id::LOCAL_CRATE; @@ -111,22 +110,19 @@ fn prepare_lto( } let archive = ArchiveRO::open(&path).expect("wanted an rlib"); - let bytecodes = archive + let obj_files = archive .iter() .filter_map(|child| child.ok().and_then(|c| c.name().map(|name| (name, c)))) - .filter(|&(name, _)| name.ends_with(RLIB_BYTECODE_EXTENSION)); - for (name, data) in bytecodes { - let _timer = - cgcx.prof.generic_activity_with_arg("LLVM_lto_load_upstream_bitcode", name); - info!("adding bytecode {}", name); - let bc_encoded = data.data(); - - let (bc, id) = match DecodedBytecode::new(bc_encoded) { - Ok(b) => Ok((b.bytecode(), b.identifier().to_string())), - Err(e) => Err(diag_handler.fatal(&e)), - }?; - let bc = SerializedModule::FromRlib(bc); - upstream_modules.push((bc, CString::new(id).unwrap())); + .filter(|&(name, _)| looks_like_rust_object_file(name)); + for (name, child) in obj_files { + info!("adding bitcode from {}", name); + match get_bitcode_slice_from_object_data(child.data()) { + Ok(data) => { + let module = SerializedModule::FromRlib(data.to_vec()); + upstream_modules.push((module, CString::new(name).unwrap())); + } + Err(msg) => return Err(diag_handler.fatal(&msg)), + } } } } @@ -134,6 +130,26 @@ fn prepare_lto( Ok((symbol_white_list, upstream_modules)) } +fn get_bitcode_slice_from_object_data(obj: &[u8]) -> Result<&[u8], String> { + let mut len = 0; + let data = + unsafe { llvm::LLVMRustGetBitcodeSliceFromObjectData(obj.as_ptr(), obj.len(), &mut len) }; + if !data.is_null() { + assert!(len != 0); + let bc = unsafe { slice::from_raw_parts(data, len) }; + + // `bc` must be a sub-slice of `obj`. + assert!(obj.as_ptr() <= bc.as_ptr()); + assert!(bc[bc.len()..bc.len()].as_ptr() <= obj[obj.len()..obj.len()].as_ptr()); + + Ok(bc) + } else { + assert!(len == 0); + let msg = llvm::last_error().unwrap_or_else(|| "unknown LLVM error".to_string()); + Err(format!("failed to get bitcode from object file for LTO ({})", msg)) + } +} + /// Performs fat LTO by merging all modules into a single one and returning it /// for further optimization. pub(crate) fn run_fat( diff --git a/src/librustc_codegen_llvm/back/write.rs b/src/librustc_codegen_llvm/back/write.rs index 3ec7ef831b5..6d175fda45f 100644 --- a/src/librustc_codegen_llvm/back/write.rs +++ b/src/librustc_codegen_llvm/back/write.rs @@ -1,5 +1,4 @@ use crate::attributes; -use crate::back::bytecode; use crate::back::lto::ThinBuffer; use crate::back::profiling::{ selfprofile_after_pass_callback, selfprofile_before_pass_callback, LlvmSelfProfiler, @@ -16,7 +15,7 @@ use crate::ModuleLlvm; use log::debug; use rustc_codegen_ssa::back::write::{BitcodeSection, CodegenContext, EmitObj, ModuleConfig}; use rustc_codegen_ssa::traits::*; -use rustc_codegen_ssa::{CompiledModule, ModuleCodegen, RLIB_BYTECODE_EXTENSION}; +use rustc_codegen_ssa::{CompiledModule, ModuleCodegen}; use rustc_data_structures::small_c_str::SmallCStr; use rustc_errors::{FatalError, Handler}; use rustc_fs_util::{link_or_copy, path_to_c_string}; @@ -654,19 +653,6 @@ pub(crate) unsafe fn codegen( ); embed_bitcode(cgcx, llcx, llmod, Some(data)); } - - if config.emit_bc_compressed { - let _timer = cgcx.prof.generic_activity_with_arg( - "LLVM_module_codegen_emit_compressed_bitcode", - &module.name[..], - ); - let dst = bc_out.with_extension(RLIB_BYTECODE_EXTENSION); - let data = bytecode::encode(&module.name, data); - if let Err(e) = fs::write(&dst, data) { - let msg = format!("failed to write bytecode to {}: {}", dst.display(), e); - diag_handler.err(&msg); - } - } } else if config.emit_obj == EmitObj::ObjectCode(BitcodeSection::Marker) { embed_bitcode(cgcx, llcx, llmod, None); } @@ -777,7 +763,6 @@ pub(crate) unsafe fn codegen( Ok(module.into_compiled_module( config.emit_obj != EmitObj::None, config.emit_bc, - config.emit_bc_compressed, &cgcx.output_filenames, )) } @@ -832,6 +817,55 @@ unsafe fn embed_bitcode( let section = if is_apple { "__LLVM,__cmdline\0" } else { ".llvmcmd\0" }; llvm::LLVMSetSection(llglobal, section.as_ptr().cast()); llvm::LLVMRustSetLinkage(llglobal, llvm::Linkage::PrivateLinkage); + + // We're adding custom sections to the output object file, but we definitely + // do not want these custom sections to make their way into the final linked + // executable. The purpose of these custom sections is for tooling + // surrounding object files to work with the LLVM IR, if necessary. For + // example rustc's own LTO will look for LLVM IR inside of the object file + // in these sections by default. + // + // To handle this is a bit different depending on the object file format + // used by the backend, broken down into a few different categories: + // + // * Mach-O - this is for macOS. Inspecting the source code for the native + // linker here shows that the `.llvmbc` and `.llvmcmd` sections are + // automatically skipped by the linker. In that case there's nothing extra + // that we need to do here. + // + // * Wasm - the native LLD linker is hard-coded to skip `.llvmbc` and + // `.llvmcmd` sections, so there's nothing extra we need to do. + // + // * COFF - if we don't do anything the linker will by default copy all + // these sections to the output artifact, not what we want! To subvert + // this we want to flag the sections we inserted here as + // `IMAGE_SCN_LNK_REMOVE`. Unfortunately though LLVM has no native way to + // do this. Thankfully though we can do this with some inline assembly, + // which is easy enough to add via module-level global inline asm. + // + // * ELF - this is very similar to COFF above. One difference is that these + // sections are removed from the output linked artifact when + // `--gc-sections` is passed, which we pass by default. If that flag isn't + // passed though then these sections will show up in the final output. + // Additionally the flag that we need to set here is `SHF_EXCLUDE`. + if is_apple + || cgcx.opts.target_triple.triple().starts_with("wasm") + || cgcx.opts.target_triple.triple().starts_with("asmjs") + { + // nothing to do here + } else if cgcx.opts.target_triple.triple().contains("windows") { + let asm = " + .section .llvmbc,\"n\" + .section .llvmcmd,\"n\" + "; + llvm::LLVMRustAppendModuleInlineAsm(llmod, asm.as_ptr().cast(), asm.len()); + } else { + let asm = " + .section .llvmbc,\"e\" + .section .llvmcmd,\"e\" + "; + llvm::LLVMRustAppendModuleInlineAsm(llmod, asm.as_ptr().cast(), asm.len()); + } } pub unsafe fn with_llvm_pmb( diff --git a/src/librustc_codegen_llvm/lib.rs b/src/librustc_codegen_llvm/lib.rs index 42302a56b41..63af60e14db 100644 --- a/src/librustc_codegen_llvm/lib.rs +++ b/src/librustc_codegen_llvm/lib.rs @@ -40,7 +40,6 @@ use std::sync::Arc; mod back { pub mod archive; - pub mod bytecode; pub mod lto; mod profiling; pub mod write; diff --git a/src/librustc_codegen_llvm/llvm/ffi.rs b/src/librustc_codegen_llvm/llvm/ffi.rs index fd03812cccd..477712f5053 100644 --- a/src/librustc_codegen_llvm/llvm/ffi.rs +++ b/src/librustc_codegen_llvm/llvm/ffi.rs @@ -2137,6 +2137,11 @@ extern "C" { len: usize, Identifier: *const c_char, ) -> Option<&Module>; + pub fn LLVMRustGetBitcodeSliceFromObjectData( + Data: *const u8, + len: usize, + out_len: &mut usize, + ) -> *const u8; pub fn LLVMRustThinLTOGetDICompileUnit( M: &Module, CU1: &mut *mut c_void, diff --git a/src/librustc_codegen_ssa/back/link.rs b/src/librustc_codegen_ssa/back/link.rs index 9d42db8ec42..9f85105a266 100644 --- a/src/librustc_codegen_ssa/back/link.rs +++ b/src/librustc_codegen_ssa/back/link.rs @@ -18,10 +18,7 @@ use super::archive::ArchiveBuilder; use super::command::Command; use super::linker::Linker; use super::rpath::{self, RPathConfig}; -use crate::{ - looks_like_rust_object_file, CodegenResults, CrateInfo, METADATA_FILENAME, - RLIB_BYTECODE_EXTENSION, -}; +use crate::{looks_like_rust_object_file, CodegenResults, CrateInfo, METADATA_FILENAME}; use cc::windows_registry; use tempfile::{Builder as TempFileBuilder, TempDir}; @@ -130,10 +127,6 @@ pub fn link_binary<'a, B: ArchiveBuilder<'a>>( remove(sess, obj); } } - for obj in codegen_results.modules.iter().filter_map(|m| m.bytecode_compressed.as_ref()) - { - remove(sess, obj); - } if let Some(ref metadata_module) = codegen_results.metadata_module { if let Some(ref obj) = metadata_module.object { remove(sess, obj); @@ -143,9 +136,6 @@ pub fn link_binary<'a, B: ArchiveBuilder<'a>>( if let Some(ref obj) = allocator_module.object { remove(sess, obj); } - if let Some(ref bc) = allocator_module.bytecode_compressed { - remove(sess, bc); - } } } }); @@ -378,14 +368,6 @@ fn link_rlib<'a, B: ArchiveBuilder<'a>>( // contain the metadata in a separate file. ab.add_file(&emit_metadata(sess, &codegen_results.metadata, tmpdir)); - // For LTO purposes, the bytecode of this library is also inserted - // into the archive. - for bytecode in - codegen_results.modules.iter().filter_map(|m| m.bytecode_compressed.as_ref()) - { - ab.add_file(bytecode); - } - // After adding all files to the archive, we need to update the // symbol table of the archive. This currently dies on macOS (see // #11162), and isn't necessary there anyway @@ -1829,7 +1811,7 @@ fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>( let mut any_objects = false; for f in archive.src_files() { - if f.ends_with(RLIB_BYTECODE_EXTENSION) || f == METADATA_FILENAME { + if f == METADATA_FILENAME { archive.remove_file(&f); continue; } diff --git a/src/librustc_codegen_ssa/back/write.rs b/src/librustc_codegen_ssa/back/write.rs index c84f38670f7..5b105dff80b 100644 --- a/src/librustc_codegen_ssa/back/write.rs +++ b/src/librustc_codegen_ssa/back/write.rs @@ -5,7 +5,6 @@ use super::symbol_export::symbol_name_for_instance_in_crate; use crate::{ CachedModuleCodegen, CodegenResults, CompiledModule, CrateInfo, ModuleCodegen, ModuleKind, - RLIB_BYTECODE_EXTENSION, }; use crate::traits::*; @@ -100,7 +99,6 @@ pub struct ModuleConfig { pub emit_pre_lto_bc: bool, pub emit_no_opt_bc: bool, pub emit_bc: bool, - pub emit_bc_compressed: bool, pub emit_ir: bool, pub emit_asm: bool, pub emit_obj: EmitObj, @@ -150,9 +148,10 @@ impl ModuleConfig { || sess.opts.cg.linker_plugin_lto.enabled() { EmitObj::Bitcode - } else if sess.opts.debugging_opts.embed_bitcode { + } else if sess.opts.debugging_opts.embed_bitcode || need_crate_bitcode_for_rlib(sess) { + let force_full = need_crate_bitcode_for_rlib(sess); match sess.opts.optimize { - config::OptLevel::No | config::OptLevel::Less => { + config::OptLevel::No | config::OptLevel::Less if !force_full => { EmitObj::ObjectCode(BitcodeSection::Marker) } _ => EmitObj::ObjectCode(BitcodeSection::Full), @@ -204,16 +203,6 @@ impl ModuleConfig { save_temps || sess.opts.output_types.contains_key(&OutputType::Bitcode), save_temps ), - emit_bc_compressed: match kind { - ModuleKind::Regular | ModuleKind::Allocator => { - // Emit compressed bitcode files for the crate if we're - // emitting an rlib. Whenever an rlib is created, the - // bitcode is inserted into the archive in order to allow - // LTO against it. - need_crate_bitcode_for_rlib(sess) - } - ModuleKind::Metadata => false, - }, emit_ir: if_regular!( sess.opts.output_types.contains_key(&OutputType::LlvmAssembly), false @@ -269,7 +258,6 @@ impl ModuleConfig { pub fn bitcode_needed(&self) -> bool { self.emit_bc - || self.emit_bc_compressed || self.emit_obj == EmitObj::Bitcode || self.emit_obj == EmitObj::ObjectCode(BitcodeSection::Full) } @@ -495,9 +483,6 @@ fn copy_all_cgu_workproducts_to_incr_comp_cache_dir( if let Some(ref path) = module.bytecode { files.push((WorkProductFileKind::Bytecode, path.clone())); } - if let Some(ref path) = module.bytecode_compressed { - files.push((WorkProductFileKind::BytecodeCompressed, path.clone())); - } if let Some((id, product)) = copy_cgu_workproducts_to_incr_comp_cache_dir(sess, &module.name, &files) @@ -834,7 +819,6 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>( let incr_comp_session_dir = cgcx.incr_comp_session_dir.as_ref().unwrap(); let mut object = None; let mut bytecode = None; - let mut bytecode_compressed = None; for (kind, saved_file) in &module.source.saved_files { let obj_out = match kind { WorkProductFileKind::Object => { @@ -847,14 +831,6 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>( bytecode = Some(path.clone()); path } - WorkProductFileKind::BytecodeCompressed => { - let path = cgcx - .output_filenames - .temp_path(OutputType::Bitcode, Some(&module.name)) - .with_extension(RLIB_BYTECODE_EXTENSION); - bytecode_compressed = Some(path.clone()); - path - } }; let source_file = in_incr_comp_dir(&incr_comp_session_dir, &saved_file); debug!( @@ -876,14 +852,12 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>( assert_eq!(object.is_some(), module_config.emit_obj != EmitObj::None); assert_eq!(bytecode.is_some(), module_config.emit_bc); - assert_eq!(bytecode_compressed.is_some(), module_config.emit_bc_compressed); Ok(WorkItemResult::Compiled(CompiledModule { name: module.name, kind: ModuleKind::Regular, object, bytecode, - bytecode_compressed, })) } diff --git a/src/librustc_codegen_ssa/lib.rs b/src/librustc_codegen_ssa/lib.rs index 5ba06bd8665..7dc09b595c3 100644 --- a/src/librustc_codegen_ssa/lib.rs +++ b/src/librustc_codegen_ssa/lib.rs @@ -55,31 +55,18 @@ pub struct ModuleCodegen<M> { // FIXME(eddyb) maybe include the crate name in this? pub const METADATA_FILENAME: &str = "lib.rmeta"; -pub const RLIB_BYTECODE_EXTENSION: &str = "bc.z"; impl<M> ModuleCodegen<M> { pub fn into_compiled_module( self, emit_obj: bool, emit_bc: bool, - emit_bc_compressed: bool, outputs: &OutputFilenames, ) -> CompiledModule { let object = emit_obj.then(|| outputs.temp_path(OutputType::Object, Some(&self.name))); let bytecode = emit_bc.then(|| outputs.temp_path(OutputType::Bitcode, Some(&self.name))); - let bytecode_compressed = emit_bc_compressed.then(|| { - outputs - .temp_path(OutputType::Bitcode, Some(&self.name)) - .with_extension(RLIB_BYTECODE_EXTENSION) - }); - - CompiledModule { - name: self.name.clone(), - kind: self.kind, - object, - bytecode, - bytecode_compressed, - } + + CompiledModule { name: self.name.clone(), kind: self.kind, object, bytecode } } } @@ -89,7 +76,6 @@ pub struct CompiledModule { pub kind: ModuleKind, pub object: Option<PathBuf>, pub bytecode: Option<PathBuf>, - pub bytecode_compressed: Option<PathBuf>, } pub struct CachedModuleCodegen { diff --git a/src/librustc_incremental/persist/work_product.rs b/src/librustc_incremental/persist/work_product.rs index 4dd81b1df57..3601b997059 100644 --- a/src/librustc_incremental/persist/work_product.rs +++ b/src/librustc_incremental/persist/work_product.rs @@ -21,7 +21,6 @@ pub fn copy_cgu_workproducts_to_incr_comp_cache_dir( let extension = match kind { WorkProductFileKind::Object => "o", WorkProductFileKind::Bytecode => "bc", - WorkProductFileKind::BytecodeCompressed => "bc.z", }; let file_name = format!("{}.{}", cgu_name, extension); let path_in_incr_dir = in_incr_comp_dir_sess(sess, &file_name); diff --git a/src/librustc_query_system/dep_graph/graph.rs b/src/librustc_query_system/dep_graph/graph.rs index fa2b51058a3..ba3ce16ae36 100644 --- a/src/librustc_query_system/dep_graph/graph.rs +++ b/src/librustc_query_system/dep_graph/graph.rs @@ -868,7 +868,6 @@ pub struct WorkProduct { pub enum WorkProductFileKind { Object, Bytecode, - BytecodeCompressed, } #[derive(Clone)] diff --git a/src/llvm-project b/src/llvm-project -Subproject 9f9da27fbdb0ba7d887f8d2521e082f12b00941 +Subproject 3ba91917e52bd66ac37161ad4a1bc87d32aa2e1 diff --git a/src/rustllvm/PassWrapper.cpp b/src/rustllvm/PassWrapper.cpp index e31dd77d8af..e1d75418243 100644 --- a/src/rustllvm/PassWrapper.cpp +++ b/src/rustllvm/PassWrapper.cpp @@ -13,6 +13,8 @@ #include "llvm/IR/AssemblyAnnotationWriter.h" #include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/Verifier.h" +#include "llvm/Object/ObjectFile.h" +#include "llvm/Object/IRObjectFile.h" #include "llvm/Passes/PassBuilder.h" #if LLVM_VERSION_GE(9, 0) #include "llvm/Passes/StandardInstrumentations.h" @@ -1475,6 +1477,32 @@ LLVMRustParseBitcodeForLTO(LLVMContextRef Context, return wrap(std::move(*SrcOrError).release()); } +// Find the bitcode section in the object file data and return it as a slice. +// Fail if the bitcode section is present but empty. +// +// On success, the return value is the pointer to the start of the slice and +// `out_len` is filled with the (non-zero) length. On failure, the return value +// is `nullptr` and `out_len` is set to zero. +extern "C" const char* +LLVMRustGetBitcodeSliceFromObjectData(const char *data, + size_t len, + size_t *out_len) { + *out_len = 0; + + StringRef Data(data, len); + MemoryBufferRef Buffer(Data, ""); // The id is unused. + + Expected<MemoryBufferRef> BitcodeOrError = + object::IRObjectFile::findBitcodeInMemBuffer(Buffer); + if (!BitcodeOrError) { + LLVMRustSetLastError(toString(BitcodeOrError.takeError()).c_str()); + return nullptr; + } + + *out_len = BitcodeOrError->getBufferSize(); + return BitcodeOrError->getBufferStart(); +} + // Rewrite all `DICompileUnit` pointers to the `DICompileUnit` specified. See // the comment in `back/lto.rs` for why this exists. extern "C" void diff --git a/src/test/ui/auxiliary/lto-rustc-loads-linker-plugin.rs b/src/test/ui/auxiliary/lto-rustc-loads-linker-plugin.rs new file mode 100644 index 00000000000..d24375b2d0a --- /dev/null +++ b/src/test/ui/auxiliary/lto-rustc-loads-linker-plugin.rs @@ -0,0 +1,6 @@ +// compile-flags: -Clinker-plugin-lto +// no-prefer-dynamic + +#![crate_type = "rlib"] + +pub fn foo() {} diff --git a/src/test/ui/lto-duplicate-symbols.stderr b/src/test/ui/lto-duplicate-symbols.stderr index 02204830120..713b79bae32 100644 --- a/src/test/ui/lto-duplicate-symbols.stderr +++ b/src/test/ui/lto-duplicate-symbols.stderr @@ -1,6 +1,6 @@ warning: Linking globals named 'foo': symbol multiply defined! -error: failed to load bc of "lto_duplicate_symbols2.3a1fbbbh-cgu.0": +error: failed to load bc of "lto-duplicate-symbols2.lto_duplicate_symbols2.3a1fbbbh-cgu.0.rcgu.o": error: aborting due to previous error; 1 warning emitted diff --git a/src/test/ui/lto-rustc-loads-linker-plugin.rs b/src/test/ui/lto-rustc-loads-linker-plugin.rs new file mode 100644 index 00000000000..6ef1d4540b8 --- /dev/null +++ b/src/test/ui/lto-rustc-loads-linker-plugin.rs @@ -0,0 +1,17 @@ +// compile-flags: -C lto +// aux-build:lto-rustc-loads-linker-plugin.rs +// run-pass +// no-prefer-dynamic + +// This test ensures that if a dependency was compiled with +// `-Clinker-plugin-lto` then we can compile with `-Clto` and still link against +// that upstream rlib. This should work because LTO implies we're not actually +// linking against upstream rlibs since we're generating the object code +// locally. This test will fail if rustc can't find bytecode in rlibs compiled +// with `-Clinker-plugin-lto`. + +extern crate lto_rustc_loads_linker_plugin; + +fn main() { + lto_rustc_loads_linker_plugin::foo(); +} diff --git a/src/test/ui/lto-thin-rustc-loads-linker-plugin.rs b/src/test/ui/lto-thin-rustc-loads-linker-plugin.rs new file mode 100644 index 00000000000..4d54ce32fb5 --- /dev/null +++ b/src/test/ui/lto-thin-rustc-loads-linker-plugin.rs @@ -0,0 +1,13 @@ +// compile-flags: -C lto=thin +// aux-build:lto-rustc-loads-linker-plugin.rs +// run-pass +// no-prefer-dynamic + +// Same as the adjacent `lto-thin-rustc-loads-linker-plugin.rs` test, only with +// ThinLTO. + +extern crate lto_rustc_loads_linker_plugin; + +fn main() { + lto_rustc_loads_linker_plugin::foo(); +} |