From 267d55d44acf6bb2821de39d4f868650ff0a9c7b Mon Sep 17 00:00:00 2001 From: bjorn3 Date: Mon, 29 Mar 2021 11:39:13 +0200 Subject: [PATCH] Use the object crate for metadata reading --- Cargo.lock | 9 ++ compiler/rustc_codegen_cranelift/src/lib.rs | 2 +- .../rustc_codegen_cranelift/src/metadata.rs | 66 +------------- compiler/rustc_codegen_llvm/src/lib.rs | 2 +- compiler/rustc_codegen_llvm/src/metadata.rs | 89 ------------------- compiler/rustc_codegen_ssa/Cargo.toml | 1 + .../rustc_codegen_ssa/src/back/metadata.rs | 65 ++++++++++++++ compiler/rustc_codegen_ssa/src/back/mod.rs | 1 + 8 files changed, 79 insertions(+), 156 deletions(-) create mode 100644 compiler/rustc_codegen_ssa/src/back/metadata.rs diff --git a/Cargo.lock b/Cargo.lock index 77b917448e9..dc688e3a513 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -2348,8 +2348,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "8d3b63360ec3cb337817c2dbd47ab4a0f170d285d8e5a2064600f3def1402397" dependencies = [ "compiler_builtins", + "flate2", "rustc-std-workspace-alloc", "rustc-std-workspace-core", + "wasmparser", ] [[package]] @@ -3700,6 +3702,7 @@ dependencies = [ "itertools 0.9.0", "jobserver", "libc", + "object", "pathdiff", "rustc_apfloat", "rustc_ast", @@ -5618,6 +5621,12 @@ dependencies = [ "rustc-std-workspace-core", ] +[[package]] +name = "wasmparser" +version = "0.57.0" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "32fddd575d477c6e9702484139cf9f23dcd554b06d185ed0f56c857dd3a47aa6" + [[package]] name = "winapi" version = "0.2.8" diff --git a/compiler/rustc_codegen_cranelift/src/lib.rs b/compiler/rustc_codegen_cranelift/src/lib.rs index 32f40395702..1ade7c77d12 100644 --- a/compiler/rustc_codegen_cranelift/src/lib.rs +++ b/compiler/rustc_codegen_cranelift/src/lib.rs @@ -165,7 +165,7 @@ fn init(&self, sess: &Session) { } fn metadata_loader(&self) -> Box { - Box::new(crate::metadata::CraneliftMetadataLoader) + Box::new(rustc_codegen_ssa::back::metadata::DefaultMetadataLoader) } fn provide(&self, _providers: &mut Providers) {} diff --git a/compiler/rustc_codegen_cranelift/src/metadata.rs b/compiler/rustc_codegen_cranelift/src/metadata.rs index 882232fde09..ab238244d68 100644 --- a/compiler/rustc_codegen_cranelift/src/metadata.rs +++ b/compiler/rustc_codegen_cranelift/src/metadata.rs @@ -1,73 +1,9 @@ -//! Reading and writing of the rustc metadata for rlibs and dylibs +//! Writing of the rustc metadata for dylibs -use std::fs::File; -use std::path::Path; - -use rustc_codegen_ssa::METADATA_FILENAME; -use rustc_data_structures::memmap::Mmap; -use rustc_data_structures::owning_ref::OwningRef; -use rustc_data_structures::rustc_erase_owner; -use rustc_data_structures::sync::MetadataRef; -use rustc_middle::middle::cstore::MetadataLoader; use rustc_middle::ty::TyCtxt; -use rustc_target::spec::Target; use crate::backend::WriteMetadata; -/// The metadata loader used by cg_clif. -/// -/// The metadata is stored in the same format as cg_llvm. -/// -/// # Metadata location -/// -///
-///
rlib
-///
The metadata can be found in the `lib.rmeta` file inside of the ar archive.
-///
dylib
-///
The metadata can be found in the `.rustc` section of the shared library.
-///
-pub(crate) struct CraneliftMetadataLoader; - -fn load_metadata_with( - path: &Path, - f: impl for<'a> FnOnce(&'a [u8]) -> Result<&'a [u8], String>, -) -> Result { - let file = File::open(path).map_err(|e| format!("{:?}", e))?; - let data = unsafe { Mmap::map(file) }.map_err(|e| format!("{:?}", e))?; - let metadata = OwningRef::new(data).try_map(f)?; - return Ok(rustc_erase_owner!(metadata.map_owner_box())); -} - -impl MetadataLoader for CraneliftMetadataLoader { - fn get_rlib_metadata(&self, _target: &Target, path: &Path) -> Result { - load_metadata_with(path, |data| { - let archive = object::read::archive::ArchiveFile::parse(&*data) - .map_err(|e| format!("{:?}", e))?; - - for entry_result in archive.members() { - let entry = entry_result.map_err(|e| format!("{:?}", e))?; - if entry.name() == METADATA_FILENAME.as_bytes() { - return Ok(entry.data()); - } - } - - Err("couldn't find metadata entry".to_string()) - }) - } - - fn get_dylib_metadata(&self, _target: &Target, path: &Path) -> Result { - use object::{Object, ObjectSection}; - - load_metadata_with(path, |data| { - let file = object::File::parse(&data).map_err(|e| format!("parse: {:?}", e))?; - file.section_by_name(".rustc") - .ok_or("no .rustc section")? - .data() - .map_err(|e| format!("failed to read .rustc section: {:?}", e)) - }) - } -} - // Adapted from https://github.com/rust-lang/rust/blob/da573206f87b5510de4b0ee1a9c044127e409bd3/src/librustc_codegen_llvm/base.rs#L47-L112 pub(crate) fn write_metadata(tcx: TyCtxt<'_>, object: &mut O) { use snap::write::FrameEncoder; diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs index 5ca4b226c38..8f95afc1b91 100644 --- a/compiler/rustc_codegen_llvm/src/lib.rs +++ b/compiler/rustc_codegen_llvm/src/lib.rs @@ -250,7 +250,7 @@ fn target_features(&self, sess: &Session) -> Vec { } fn metadata_loader(&self) -> Box { - Box::new(metadata::LlvmMetadataLoader) + Box::new(rustc_codegen_ssa::back::metadata::DefaultMetadataLoader) } fn provide(&self, providers: &mut ty::query::Providers) { diff --git a/compiler/rustc_codegen_llvm/src/metadata.rs b/compiler/rustc_codegen_llvm/src/metadata.rs index decc1e1f700..4bad93a7567 100644 --- a/compiler/rustc_codegen_llvm/src/metadata.rs +++ b/compiler/rustc_codegen_llvm/src/metadata.rs @@ -1,94 +1,9 @@ -use crate::llvm; -use crate::llvm::archive_ro::ArchiveRO; -use crate::llvm::{mk_section_iter, False, ObjectFile}; -use rustc_middle::middle::cstore::MetadataLoader; use rustc_target::spec::Target; -use rustc_codegen_ssa::METADATA_FILENAME; -use rustc_data_structures::owning_ref::OwningRef; -use rustc_data_structures::rustc_erase_owner; -use tracing::debug; - use rustc_fs_util::path_to_c_string; use std::path::Path; use std::slice; -pub use rustc_data_structures::sync::MetadataRef; - -pub struct LlvmMetadataLoader; - -impl MetadataLoader for LlvmMetadataLoader { - fn get_rlib_metadata(&self, _: &Target, filename: &Path) -> Result { - // Use ArchiveRO for speed here, it's backed by LLVM and uses mmap - // internally to read the file. We also avoid even using a memcpy by - // just keeping the archive along while the metadata is in use. - let archive = - ArchiveRO::open(filename).map(|ar| OwningRef::new(Box::new(ar))).map_err(|e| { - debug!("llvm didn't like `{}`: {}", filename.display(), e); - format!("failed to read rlib metadata in '{}': {}", filename.display(), e) - })?; - let buf: OwningRef<_, [u8]> = archive.try_map(|ar| { - ar.iter() - .filter_map(|s| s.ok()) - .find(|sect| sect.name() == Some(METADATA_FILENAME)) - .map(|s| s.data()) - .ok_or_else(|| { - debug!("didn't find '{}' in the archive", METADATA_FILENAME); - format!("failed to read rlib metadata: '{}'", filename.display()) - }) - })?; - Ok(rustc_erase_owner!(buf)) - } - - fn get_dylib_metadata(&self, target: &Target, filename: &Path) -> Result { - unsafe { - let buf = path_to_c_string(filename); - let mb = llvm::LLVMRustCreateMemoryBufferWithContentsOfFile(buf.as_ptr()) - .ok_or_else(|| format!("error reading library: '{}'", filename.display()))?; - let of = - ObjectFile::new(mb).map(|of| OwningRef::new(Box::new(of))).ok_or_else(|| { - format!("provided path not an object file: '{}'", filename.display()) - })?; - let buf = of.try_map(|of| search_meta_section(of, target, filename))?; - Ok(rustc_erase_owner!(buf)) - } - } -} - -fn search_meta_section<'a>( - of: &'a ObjectFile, - target: &Target, - filename: &Path, -) -> Result<&'a [u8], String> { - unsafe { - let si = mk_section_iter(of.llof); - while llvm::LLVMIsSectionIteratorAtEnd(of.llof, si.llsi) == False { - let mut name_buf = None; - let name_len = llvm::LLVMRustGetSectionName(si.llsi, &mut name_buf); - let name = name_buf.map_or_else( - String::new, // We got a null ptr, ignore `name_len`. - |buf| { - String::from_utf8( - slice::from_raw_parts(buf.as_ptr() as *const u8, name_len as usize) - .to_vec(), - ) - .unwrap() - }, - ); - debug!("get_metadata_section: name {}", name); - if read_metadata_section_name(target) == name { - let cbuf = llvm::LLVMGetSectionContents(si.llsi); - let csz = llvm::LLVMGetSectionSize(si.llsi) as usize; - // The buffer is valid while the object file is around - let buf: &'a [u8] = slice::from_raw_parts(cbuf as *const u8, csz); - return Ok(buf); - } - llvm::LLVMMoveToNextSection(si.llsi); - } - } - Err(format!("metadata not found: '{}'", filename.display())) -} - pub fn metadata_section_name(target: &Target) -> &'static str { // Historical note: // @@ -106,7 +21,3 @@ pub fn metadata_section_name(target: &Target) -> &'static str { if target.is_like_osx { "__DATA,.rustc" } else { ".rustc" } } - -fn read_metadata_section_name(_target: &Target) -> &'static str { - ".rustc" -} diff --git a/compiler/rustc_codegen_ssa/Cargo.toml b/compiler/rustc_codegen_ssa/Cargo.toml index 7a3d715df6d..d7d91d09cfa 100644 --- a/compiler/rustc_codegen_ssa/Cargo.toml +++ b/compiler/rustc_codegen_ssa/Cargo.toml @@ -16,6 +16,7 @@ libc = "0.2.50" jobserver = "0.1.22" tempfile = "3.2" pathdiff = "0.2.0" +object = "0.22.0" rustc_serialize = { path = "../rustc_serialize" } rustc_ast = { path = "../rustc_ast" } diff --git a/compiler/rustc_codegen_ssa/src/back/metadata.rs b/compiler/rustc_codegen_ssa/src/back/metadata.rs new file mode 100644 index 00000000000..096098fb260 --- /dev/null +++ b/compiler/rustc_codegen_ssa/src/back/metadata.rs @@ -0,0 +1,65 @@ +//! Reading of the rustc metadata for rlibs and dylibs + +use std::fs::File; +use std::path::Path; + +use rustc_data_structures::memmap::Mmap; +use rustc_data_structures::owning_ref::OwningRef; +use rustc_data_structures::rustc_erase_owner; +use rustc_data_structures::sync::MetadataRef; +use rustc_middle::middle::cstore::MetadataLoader; +use rustc_target::spec::Target; + +use crate::METADATA_FILENAME; + +/// The default metadata loader. This is used by cg_llvm and cg_clif. +/// +/// # Metadata location +/// +///
+///
rlib
+///
The metadata can be found in the `lib.rmeta` file inside of the ar archive.
+///
dylib
+///
The metadata can be found in the `.rustc` section of the shared library.
+///
+pub struct DefaultMetadataLoader; + +fn load_metadata_with( + path: &Path, + f: impl for<'a> FnOnce(&'a [u8]) -> Result<&'a [u8], String>, +) -> Result { + let file = File::open(path).map_err(|e| format!("{:?}", e))?; + let data = unsafe { Mmap::map(file) }.map_err(|e| format!("{:?}", e))?; + let metadata = OwningRef::new(data).try_map(f)?; + return Ok(rustc_erase_owner!(metadata.map_owner_box())); +} + +impl MetadataLoader for DefaultMetadataLoader { + fn get_rlib_metadata(&self, _target: &Target, path: &Path) -> Result { + load_metadata_with(path, |data| { + let archive = object::read::archive::ArchiveFile::parse(&*data) + .map_err(|e| format!("{:?}", e))?; + + for entry_result in archive.members() { + let entry = entry_result.map_err(|e| format!("{:?}", e))?; + if entry.name() == METADATA_FILENAME.as_bytes() { + return Ok(entry.data()); + } + } + + Err("couldn't find metadata entry".to_string()) + }) + } + + fn get_dylib_metadata(&self, _target: &Target, path: &Path) -> Result { + use object::{Object, ObjectSection}; + + load_metadata_with(path, |data| { + let file = object::File::parse(&data).map_err(|e| format!("parse: {:?}", e))?; + file.section_by_name(".rustc") + .ok_or("no .rustc section")? + .data() + .map_err(|e| format!("failed to read .rustc section: {:?}", e)) + }) + } +} diff --git a/compiler/rustc_codegen_ssa/src/back/mod.rs b/compiler/rustc_codegen_ssa/src/back/mod.rs index 20ca503d43f..d11ed54eb20 100644 --- a/compiler/rustc_codegen_ssa/src/back/mod.rs +++ b/compiler/rustc_codegen_ssa/src/back/mod.rs @@ -3,6 +3,7 @@ pub mod link; pub mod linker; pub mod lto; +pub mod metadata; pub mod rpath; pub mod symbol_export; pub mod write;