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Move metadata header and version checks together
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This will make it easier to report rustc versions for older metadata formats.
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@bjorn3
bjorn3 committed Mar 8, 2024
1 parent 14fbc3c commit bdfef5b
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Showing 3 changed files with 72 additions and 47 deletions.
1 change: 1 addition & 0 deletions compiler/rustc_driver_impl/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -676,6 +676,7 @@ fn list_metadata(early_dcx: &EarlyDiagCtxt, sess: &Session, metadata_loader: &dy
metadata_loader,
&mut v,
&sess.opts.unstable_opts.ls,
sess.cfg_version,
)
.unwrap();
safe_println!("{}", String::from_utf8(v).unwrap());
Expand Down
97 changes: 56 additions & 41 deletions compiler/rustc_metadata/src/locator.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -569,31 +569,47 @@ impl<'a> CrateLocator<'a> {
debug!("skipping empty file");
continue;
}
let (hash, metadata) =
match get_metadata_section(self.target, flavor, &lib, self.metadata_loader) {
Ok(blob) => {
if let Some(h) = self.crate_matches(&blob, &lib) {
(h, blob)
} else {
info!("metadata mismatch");
continue;
}
}
Err(MetadataError::LoadFailure(err)) => {
info!("no metadata found: {}", err);
// The file was present and created by the same compiler version, but we
// couldn't load it for some reason. Give a hard error instead of silently
// ignoring it, but only if we would have given an error anyway.
self.crate_rejections
.via_invalid
.push(CrateMismatch { path: lib, got: err });
continue;
}
Err(err @ MetadataError::NotPresent(_)) => {
info!("no metadata found: {}", err);
let (hash, metadata) = match get_metadata_section(
self.target,
flavor,
&lib,
self.metadata_loader,
self.cfg_version,
) {
Ok(blob) => {
if let Some(h) = self.crate_matches(&blob, &lib) {
(h, blob)
} else {
info!("metadata mismatch");
continue;
}
};
}
Err(MetadataError::VersionMismatch { expected_version, found_version }) => {
// The file was present and created by the same compiler version, but we
// couldn't load it for some reason. Give a hard error instead of silently
// ignoring it, but only if we would have given an error anyway.
info!(
"Rejecting via version: expected {} got {}",
expected_version, found_version
);
self.crate_rejections
.via_version
.push(CrateMismatch { path: lib, got: found_version });
continue;
}
Err(MetadataError::LoadFailure(err)) => {
info!("no metadata found: {}", err);
// The file was present and created by the same compiler version, but we
// couldn't load it for some reason. Give a hard error instead of silently
// ignoring it, but only if we would have given an error anyway.
self.crate_rejections.via_invalid.push(CrateMismatch { path: lib, got: err });
continue;
}
Err(err @ MetadataError::NotPresent(_)) => {
info!("no metadata found: {}", err);
continue;
}
};
// If we see multiple hashes, emit an error about duplicate candidates.
if slot.as_ref().is_some_and(|s| s.0 != hash) {
if let Some(candidates) = err_data {
Expand Down Expand Up @@ -648,16 +664,6 @@ impl<'a> CrateLocator<'a> {
}

fn crate_matches(&mut self, metadata: &MetadataBlob, libpath: &Path) -> Option<Svh> {
let rustc_version = rustc_version(self.cfg_version);
let found_version = metadata.get_rustc_version();
if found_version != rustc_version {
info!("Rejecting via version: expected {} got {}", rustc_version, found_version);
self.crate_rejections
.via_version
.push(CrateMismatch { path: libpath.to_path_buf(), got: found_version });
return None;
}

let header = metadata.get_header();
if header.is_proc_macro_crate != self.is_proc_macro {
info!(
Expand Down Expand Up @@ -770,6 +776,7 @@ fn get_metadata_section<'p>(
flavor: CrateFlavor,
filename: &'p Path,
loader: &dyn MetadataLoader,
cfg_version: &'static str,
) -> Result<MetadataBlob, MetadataError<'p>> {
if !filename.exists() {
return Err(MetadataError::NotPresent(filename));
Expand Down Expand Up @@ -847,13 +854,12 @@ fn get_metadata_section<'p>(
}
};
let blob = MetadataBlob(raw_bytes);
if blob.is_compatible() {
Ok(blob)
} else {
Err(MetadataError::LoadFailure(format!(
"invalid metadata version found: {}",
filename.display()
)))
match blob.check_compatibility(cfg_version) {
Ok(()) => Ok(blob),
Err(version) => Err(MetadataError::VersionMismatch {
expected_version: cfg_version,
found_version: version,
}),
}
}

Expand All @@ -864,9 +870,10 @@ pub fn list_file_metadata(
metadata_loader: &dyn MetadataLoader,
out: &mut dyn Write,
ls_kinds: &[String],
cfg_version: &'static str,
) -> IoResult<()> {
let flavor = get_flavor_from_path(path);
match get_metadata_section(target, flavor, path, metadata_loader) {
match get_metadata_section(target, flavor, path, metadata_loader, cfg_version) {
Ok(metadata) => metadata.list_crate_metadata(out, ls_kinds),
Err(msg) => write!(out, "{msg}\n"),
}
Expand Down Expand Up @@ -932,6 +939,8 @@ enum MetadataError<'a> {
NotPresent(&'a Path),
/// The file was present and invalid.
LoadFailure(String),
/// The file was present, but compiled with a different rustc version.
VersionMismatch { expected_version: &'static str, found_version: String },
}

impl fmt::Display for MetadataError<'_> {
Expand All @@ -941,6 +950,12 @@ impl fmt::Display for MetadataError<'_> {
f.write_str(&format!("no such file: '{}'", filename.display()))
}
MetadataError::LoadFailure(msg) => f.write_str(msg),
MetadataError::VersionMismatch { expected_version, found_version } => {
f.write_str(&format!(
"rustc version mismatch. expected {}, found {}",
expected_version, found_version,
))
}
}
}
}
Expand Down
21 changes: 15 additions & 6 deletions compiler/rustc_metadata/src/rmeta/decoder.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -684,13 +684,22 @@ impl<'a, 'tcx, I: Idx, T> Decodable<DecodeContext<'a, 'tcx>> for LazyTable<I, T>
implement_ty_decoder!(DecodeContext<'a, 'tcx>);

impl MetadataBlob {
pub(crate) fn is_compatible(&self) -> bool {
self.blob().starts_with(METADATA_HEADER)
}
pub(crate) fn check_compatibility(&self, cfg_version: &'static str) -> Result<(), String> {
if !self.blob().starts_with(METADATA_HEADER) {
if self.blob().starts_with(b"rust") {
return Err("<unknown rustc version>".to_string());
}
return Err("<invalid metadata header>".to_string());
}

pub(crate) fn get_rustc_version(&self) -> String {
LazyValue::<String>::from_position(NonZero::new(METADATA_HEADER.len() + 8).unwrap())
.decode(self)
let found_version =
LazyValue::<String>::from_position(NonZero::new(METADATA_HEADER.len() + 8).unwrap())
.decode(self);
if rustc_version(cfg_version) != found_version {
return Err(found_version);
}

Ok(())
}

fn root_pos(&self) -> NonZero<usize> {
Expand Down

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