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use crate::errors::{
FailedCreateEncodedMetadata, FailedCreateFile, FailedCreateTempdir, FailedWriteError,
};
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::{Path, PathBuf};
pub const METADATA_FILENAME: &str = "lib.rmeta";
pub fn emit_metadata(sess: &Session, metadata: &[u8], tmpdir: &MaybeTempDir) -> PathBuf {
let out_filename = tmpdir.as_ref().join(METADATA_FILENAME);
let result = fs::write(&out_filename, metadata);
if let Err(err) = result {
sess.emit_fatal(FailedWriteError { filename: out_filename, err });
}
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 crate_name = tcx.crate_name(LOCAL_CRATE);
let out_filename = filename_for_metadata(tcx.sess, crate_name.as_str(), outputs);
let metadata_tmpdir = TempFileBuilder::new()
.prefix("rmeta")
.tempdir_in(out_filename.parent().unwrap_or_else(|| Path::new("")))
.unwrap_or_else(|err| tcx.sess.emit_fatal(FailedCreateTempdir { err }));
let metadata_tmpdir = MaybeTempDir::new(metadata_tmpdir, tcx.sess.opts.cg.save_temps);
let metadata_filename = metadata_tmpdir.as_ref().join(METADATA_FILENAME);
match metadata_kind {
MetadataKind::None => {
std::fs::File::create(&metadata_filename).unwrap_or_else(|err| {
tcx.sess.emit_fatal(FailedCreateFile { filename: &metadata_filename, err });
});
}
MetadataKind::Uncompressed | MetadataKind::Compressed => {
encode_metadata(tcx, &metadata_filename);
}
};
let _prof_timer = tcx.sess.prof.generic_activity("write_crate_metadata");
let need_metadata_file = tcx.sess.opts.output_types.contains_key(&OutputType::Metadata);
let (metadata_filename, metadata_tmpdir) = if need_metadata_file {
if let Err(err) = non_durable_rename(&metadata_filename, &out_filename) {
tcx.sess.emit_fatal(FailedWriteError { filename: out_filename, err });
}
if tcx.sess.opts.json_artifact_notifications {
tcx.sess
.parse_sess
.span_diagnostic
.emit_artifact_notification(&out_filename, "metadata");
}
(out_filename, None)
} else {
(metadata_filename, Some(metadata_tmpdir))
};
let metadata =
EncodedMetadata::from_path(metadata_filename, metadata_tmpdir).unwrap_or_else(|err| {
tcx.sess.emit_fatal(FailedCreateEncodedMetadata { err });
});
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)
}
#[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)
}