granite-rust/compiler/rustc_span
bors 80926fc409 Auto merge of - michaelwoerister:lexing-ice, r=davidtwco
Disambiguate between SourceFiles from different crates even if they have the same path

This PR fixes an ICE that can occur when the compiler encounters a source file that is part of both the local crate and an upstream crate:

1. While importing source files from an upstream crate the compiler creates a `SourceFile` entry for `foo.rs` in the `SourceMap`. Since this is an imported source file its `src` field is `None`.
2. At a later point the parser encounters `foo.rs` again. It tells the `SourceMap` to load the file but because we already have an entry for `foo.rs` the `SourceMap` will return the existing version with `src == None`.
3. The parser proceeds under the assumption that `src.is_some()` and panics when actually trying to use the file's contents.

This PR fixes the issue by adding the source file's associated `CrateNum` to the `SourceMap`'s interning key. As a consequence the two instances of the file will each have a separate entry in the `SourceMap`. They just happen to share the same file path. This approach seemed less problematic to me than trying to mutate the `SourceFile` after it had already been created.

Another, more involved, approach might be to merge the `src` and the `external_src` field.

Fixes 
2021-06-22 14:53:58 +00:00
..
src Auto merge of - michaelwoerister:lexing-ice, r=davidtwco 2021-06-22 14:53:58 +00:00
Cargo.toml Add support for SHA256 source file hashing for LLVM 11+. 2020-10-14 15:09:51 -07:00