diff --git a/Cargo.lock b/Cargo.lock index ba0098a9775..dd9e4bd9a5f 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -3982,7 +3982,6 @@ dependencies = [ "rustc_ty_utils", "rustc_typeck", "smallvec", - "tempfile", "tracing", "winapi", ] @@ -4092,6 +4091,7 @@ dependencies = [ "rustc_type_ir", "smallvec", "snap", + "tempfile", "tracing", ] diff --git a/compiler/rustc_interface/Cargo.toml b/compiler/rustc_interface/Cargo.toml index 9aacfba3c82..1ecbc876c8d 100644 --- a/compiler/rustc_interface/Cargo.toml +++ b/compiler/rustc_interface/Cargo.toml @@ -46,7 +46,6 @@ rustc_query_impl = { path = "../rustc_query_impl" } rustc_resolve = { path = "../rustc_resolve" } rustc_trait_selection = { path = "../rustc_trait_selection" } rustc_ty_utils = { path = "../rustc_ty_utils" } -tempfile = "3.2" [target.'cfg(unix)'.dependencies] libc = "0.2" diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs index 6d00ce33d8f..25040307838 100644 --- a/compiler/rustc_interface/src/passes.rs +++ b/compiler/rustc_interface/src/passes.rs @@ -8,16 +8,13 @@ use rustc_borrowck as mir_borrowck; use rustc_codegen_ssa::traits::CodegenBackend; use rustc_data_structures::parallel; use rustc_data_structures::sync::{Lrc, OnceCell, WorkerLocal}; -use rustc_data_structures::temp_dir::MaybeTempDir; use rustc_errors::{Applicability, ErrorGuaranteed, MultiSpan, PResult}; use rustc_expand::base::{ExtCtxt, LintStoreExpand, ResolverExpand}; -use rustc_hir::def_id::{StableCrateId, LOCAL_CRATE}; +use rustc_hir::def_id::StableCrateId; use rustc_hir::definitions::Definitions; use rustc_hir::Crate; use rustc_lint::{EarlyCheckNode, LintStore}; use rustc_metadata::creader::CStore; -use rustc_metadata::fs::emit_metadata; -use rustc_metadata::{encode_metadata, EncodedMetadata}; use rustc_middle::arena::Arena; use rustc_middle::dep_graph::DepGraph; use rustc_middle::ty::query::{ExternProviders, Providers}; @@ -30,14 +27,13 @@ use rustc_query_impl::{OnDiskCache, Queries as TcxQueries}; use rustc_resolve::{Resolver, ResolverArenas}; use rustc_session::config::{CrateType, Input, OutputFilenames, OutputType}; use rustc_session::cstore::{CrateStoreDyn, MetadataLoader, MetadataLoaderDyn}; -use rustc_session::output::{filename_for_input, filename_for_metadata}; +use rustc_session::output::filename_for_input; use rustc_session::search_paths::PathKind; use rustc_session::{Limit, Session}; use rustc_span::symbol::{sym, Symbol}; use rustc_span::FileName; use rustc_trait_selection::traits; use rustc_typeck as typeck; -use tempfile::Builder as TempFileBuilder; use tracing::{info, warn}; use std::any::Any; @@ -1030,69 +1026,6 @@ fn analysis(tcx: TyCtxt<'_>, (): ()) -> Result<()> { Ok(()) } -fn encode_and_write_metadata( - tcx: TyCtxt<'_>, - outputs: &OutputFilenames, -) -> (EncodedMetadata, bool) { - #[derive(PartialEq, Eq, PartialOrd, Ord)] - enum MetadataKind { - None, - Uncompressed, - Compressed, - } - - let metadata_kind = tcx - .sess - .crate_types() - .iter() - .map(|ty| match *ty { - CrateType::Executable | CrateType::Staticlib | CrateType::Cdylib => MetadataKind::None, - - CrateType::Rlib => MetadataKind::Uncompressed, - - CrateType::Dylib | CrateType::ProcMacro => MetadataKind::Compressed, - }) - .max() - .unwrap_or(MetadataKind::None); - - let metadata = match metadata_kind { - MetadataKind::None => EncodedMetadata::new(), - MetadataKind::Uncompressed | MetadataKind::Compressed => encode_metadata(tcx), - }; - - let _prof_timer = tcx.sess.prof.generic_activity("write_crate_metadata"); - - let need_metadata_file = tcx.sess.opts.output_types.contains_key(&OutputType::Metadata); - if need_metadata_file { - let crate_name = tcx.crate_name(LOCAL_CRATE); - let out_filename = filename_for_metadata(tcx.sess, crate_name.as_str(), outputs); - // To avoid races with another rustc process scanning the output directory, - // we need to write the file somewhere else and atomically move it to its - // final destination, with an `fs::rename` call. In order for the rename to - // always succeed, the temporary file needs to be on the same filesystem, - // which is why we create it inside the output directory specifically. - let metadata_tmpdir = TempFileBuilder::new() - .prefix("rmeta") - .tempdir_in(out_filename.parent().unwrap()) - .unwrap_or_else(|err| tcx.sess.fatal(&format!("couldn't create a temp dir: {}", err))); - let metadata_tmpdir = MaybeTempDir::new(metadata_tmpdir, tcx.sess.opts.cg.save_temps); - let metadata_filename = emit_metadata(tcx.sess, metadata.raw_data(), &metadata_tmpdir); - if let Err(e) = util::non_durable_rename(&metadata_filename, &out_filename) { - tcx.sess.fatal(&format!("failed to write {}: {}", out_filename.display(), e)); - } - if tcx.sess.opts.json_artifact_notifications { - tcx.sess - .parse_sess - .span_diagnostic - .emit_artifact_notification(&out_filename, "metadata"); - } - } - - let need_metadata_module = metadata_kind == MetadataKind::Compressed; - - (metadata, need_metadata_module) -} - /// Runs the codegen backend, after which the AST and analysis can /// be discarded. pub fn start_codegen<'tcx>( @@ -1102,7 +1035,8 @@ pub fn start_codegen<'tcx>( ) -> Box { info!("Pre-codegen\n{:?}", tcx.debug_stats()); - let (metadata, need_metadata_module) = encode_and_write_metadata(tcx, outputs); + let (metadata, need_metadata_module) = + rustc_metadata::fs::encode_and_write_metadata(tcx, outputs); let codegen = tcx.sess.time("codegen_crate", move || { codegen_backend.codegen_crate(tcx, metadata, need_metadata_module) diff --git a/compiler/rustc_metadata/Cargo.toml b/compiler/rustc_metadata/Cargo.toml index 3ab4a8b7294..2c5db9d8b27 100644 --- a/compiler/rustc_metadata/Cargo.toml +++ b/compiler/rustc_metadata/Cargo.toml @@ -12,6 +12,7 @@ odht = { version = "0.3.1", features = ["nightly"] } snap = "1" tracing = "0.1" smallvec = { version = "1.8.1", features = ["union", "may_dangle"] } +tempfile = "3.2" rustc_middle = { path = "../rustc_middle" } rustc_attr = { path = "../rustc_attr" } rustc_data_structures = { path = "../rustc_data_structures" } diff --git a/compiler/rustc_metadata/src/fs.rs b/compiler/rustc_metadata/src/fs.rs index f57ace6f28a..b66f37d5d61 100644 --- a/compiler/rustc_metadata/src/fs.rs +++ b/compiler/rustc_metadata/src/fs.rs @@ -1,8 +1,15 @@ +use crate::{encode_metadata, EncodedMetadata}; + use rustc_data_structures::temp_dir::MaybeTempDir; +use rustc_hir::def_id::LOCAL_CRATE; +use rustc_middle::ty::TyCtxt; +use rustc_session::config::{CrateType, OutputFilenames, OutputType}; +use rustc_session::output::filename_for_metadata; use rustc_session::Session; +use tempfile::Builder as TempFileBuilder; use std::fs; -use std::path::PathBuf; +use std::path::{Path, PathBuf}; // FIXME(eddyb) maybe include the crate name in this? pub const METADATA_FILENAME: &str = "lib.rmeta"; @@ -22,3 +29,84 @@ pub fn emit_metadata(sess: &Session, metadata: &[u8], tmpdir: &MaybeTempDir) -> out_filename } + +pub fn encode_and_write_metadata( + tcx: TyCtxt<'_>, + outputs: &OutputFilenames, +) -> (EncodedMetadata, bool) { + #[derive(PartialEq, Eq, PartialOrd, Ord)] + enum MetadataKind { + None, + Uncompressed, + Compressed, + } + + let metadata_kind = tcx + .sess + .crate_types() + .iter() + .map(|ty| match *ty { + CrateType::Executable | CrateType::Staticlib | CrateType::Cdylib => MetadataKind::None, + + CrateType::Rlib => MetadataKind::Uncompressed, + + CrateType::Dylib | CrateType::ProcMacro => MetadataKind::Compressed, + }) + .max() + .unwrap_or(MetadataKind::None); + + let metadata = match metadata_kind { + MetadataKind::None => EncodedMetadata::new(), + MetadataKind::Uncompressed | MetadataKind::Compressed => encode_metadata(tcx), + }; + + let _prof_timer = tcx.sess.prof.generic_activity("write_crate_metadata"); + + let need_metadata_file = tcx.sess.opts.output_types.contains_key(&OutputType::Metadata); + if need_metadata_file { + let crate_name = tcx.crate_name(LOCAL_CRATE); + let out_filename = filename_for_metadata(tcx.sess, crate_name.as_str(), outputs); + // To avoid races with another rustc process scanning the output directory, + // we need to write the file somewhere else and atomically move it to its + // final destination, with an `fs::rename` call. In order for the rename to + // always succeed, the temporary file needs to be on the same filesystem, + // which is why we create it inside the output directory specifically. + let metadata_tmpdir = TempFileBuilder::new() + .prefix("rmeta") + .tempdir_in(out_filename.parent().unwrap()) + .unwrap_or_else(|err| tcx.sess.fatal(&format!("couldn't create a temp dir: {}", err))); + let metadata_tmpdir = MaybeTempDir::new(metadata_tmpdir, tcx.sess.opts.cg.save_temps); + let metadata_filename = emit_metadata(tcx.sess, metadata.raw_data(), &metadata_tmpdir); + if let Err(e) = non_durable_rename(&metadata_filename, &out_filename) { + tcx.sess.fatal(&format!("failed to write {}: {}", out_filename.display(), e)); + } + if tcx.sess.opts.json_artifact_notifications { + tcx.sess + .parse_sess + .span_diagnostic + .emit_artifact_notification(&out_filename, "metadata"); + } + } + + let need_metadata_module = metadata_kind == MetadataKind::Compressed; + + (metadata, need_metadata_module) +} + +#[cfg(not(target_os = "linux"))] +pub fn non_durable_rename(src: &Path, dst: &Path) -> std::io::Result<()> { + std::fs::rename(src, dst) +} + +/// This function attempts to bypass the auto_da_alloc heuristic implemented by some filesystems +/// such as btrfs and ext4. When renaming over a file that already exists then they will "helpfully" +/// write back the source file before committing the rename in case a developer forgot some of +/// the fsyncs in the open/write/fsync(file)/rename/fsync(dir) dance for atomic file updates. +/// +/// To avoid triggering this heuristic we delete the destination first, if it exists. +/// The cost of an extra syscall is much lower than getting descheduled for the sync IO. +#[cfg(target_os = "linux")] +pub fn non_durable_rename(src: &Path, dst: &Path) -> std::io::Result<()> { + let _ = std::fs::remove_file(dst); + std::fs::rename(src, dst) +}