Auto merge of #83813 - cbeuw:remap-std, r=michaelwoerister

Fix `--remap-path-prefix` not correctly remapping `rust-src` component paths and unify handling of path mapping with virtualized paths

This PR fixes #73167 ("Binaries end up containing path to the rust-src component despite `--remap-path-prefix`") by preventing real local filesystem paths from reaching compilation output if the path is supposed to be remapped.

`RealFileName::Named` introduced in #72767 is now renamed as `LocalPath`, because this variant wraps a (most likely) valid local filesystem path.

`RealFileName::Devirtualized` is renamed as `Remapped` to be used for remapped path from a real path via `--remap-path-prefix` argument, as well as real path inferred from a virtualized (during compiler bootstrapping) `/rustc/...` path. The `local_path` field is now an `Option<PathBuf>`, as it will be set to `None` before serialisation, so it never reaches any build output. Attempting to serialise a non-`None` `local_path` will cause an assertion faliure.

When a path is remapped, a `RealFileName::Remapped` variant is created. The original path is preserved in `local_path` field and the remapped path is saved in `virtual_name` field. Previously, the `local_path` is directly modified which goes against its purpose of "suitable for reading from the file system on the local host".

`rustc_span::SourceFile`'s fields `unmapped_path` (introduced by #44940) and `name_was_remapped` (introduced by #41508 when `--remap-path-prefix` feature originally added) are removed, as these two pieces of information can be inferred from the `name` field: if it's anything other than a `FileName::Real(_)`, or if it is a `FileName::Real(RealFileName::LocalPath(_))`, then clearly `name_was_remapped` would've been false and `unmapped_path` would've been `None`. If it is a `FileName::Real(RealFileName::Remapped{local_path, virtual_name})`, then `name_was_remapped` would've been true and `unmapped_path` would've been `Some(local_path)`.

cc `@eddyb` who implemented `/rustc/...` path devirtualisation
This commit is contained in:
bors 2021-05-12 11:05:56 +00:00
commit e1ff91f439
48 changed files with 442 additions and 265 deletions

View file

@ -638,10 +638,11 @@ impl server::SourceFile for Rustc<'_> {
match file.name {
FileName::Real(ref name) => name
.local_path()
.expect("attempting to get a file path in an imported file in `proc_macro::SourceFile::path`")
.to_str()
.expect("non-UTF8 file path in `proc_macro::SourceFile::path`")
.to_string(),
_ => file.name.to_string(),
_ => file.name.prefer_local().to_string(),
}
}
fn is_real(&mut self, file: &Self::SourceFile) -> bool {
@ -785,7 +786,7 @@ fn ident_name_compatibility_hack(
if let ExpnKind::Macro { name: macro_name, .. } = orig_span.ctxt().outer_expn_data().kind {
let source_map = rustc.sess.source_map();
let filename = source_map.span_to_filename(orig_span);
if let FileName::Real(RealFileName::Named(path)) = filename {
if let FileName::Real(RealFileName::LocalPath(path)) = filename {
let matches_prefix = |prefix, filename| {
// Check for a path that ends with 'prefix*/src/<filename>'
let mut iter = path.components().rev();
@ -848,7 +849,7 @@ fn ident_name_compatibility_hack(
if macro_name == sym::tuple_from_req && matches_prefix("actix-web", "extract.rs") {
let snippet = source_map.span_to_snippet(orig_span);
if snippet.as_deref() == Ok("$T") {
if let FileName::Real(RealFileName::Named(macro_path)) =
if let FileName::Real(RealFileName::LocalPath(macro_path)) =
source_map.span_to_filename(rustc.def_site)
{
if macro_path.to_string_lossy().contains("pin-project-internal-0.") {