Overhaul filename handling for cross-compiler consistency This PR overhauls the way we handle filenames in the compiler and `rmeta` in order to achieve achieve cross-compiler consistency (ie. having the same path no matter if the filename was created in the current compiler session or is coming from `rmeta`). This is required as some parts of the compiler rely on consistent paths for the soundness of generated code (see rust-lang/rust#148328). In order to achieved consistency multiple steps are being taken by this PR: - by making `RealFileName` immutable - by only having `SourceMap::to_real_filename` create `RealFileName` - currently `RealFileName` can be created from any `Path` and are remapped afterwards, which creates consistency issue - by also making `RealFileName` holds it's working directory, embeddable name and the remapped scopes - this removes the need for a `Session`, to know the current(!) scopes and cwd, which is invalid as they may not be equal to the scopes used when creating the filename In order for `SourceMap::to_real_filename` to know which scopes to apply `FilePathMapping` now takes the current remapping scopes to apply, which makes `FileNameDisplayPreference` and company useless and are removed. This PR is split-up in multiple commits (unfortunately not atomic), but should help review the changes. Unblocks https://github.com/rust-lang/rust/pull/147611 Fixes https://github.com/rust-lang/rust/issues/148328 |
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| Cargo.toml | ||
| messages.ftl | ||
| README.md | ||
The codegen crate contains the code to convert from MIR into LLVM IR,
and then from LLVM IR into machine code. In general it contains code
that runs towards the end of the compilation process.
For more information about how codegen works, see the rustc dev guide.