rust/compiler/rustc_driver_impl
Nicholas Nethercote 5d9dfbd08f Stop using String for error codes.
Error codes are integers, but `String` is used everywhere to represent
them. Gross!

This commit introduces `ErrCode`, an integral newtype for error codes,
replacing `String`. It also introduces a constant for every error code,
e.g. `E0123`, and removes the `error_code!` macro. The constants are
imported wherever used with `use rustc_errors::codes::*`.

With the old code, we have three different ways to specify an error code
at a use point:
```
error_code!(E0123)  // macro call

struct_span_code_err!(dcx, span, E0123, "msg");  // bare ident arg to macro call

\#[diag(name, code = "E0123")]  // string
struct Diag;
```

With the new code, they all use the `E0123` constant.
```
E0123  // constant

struct_span_code_err!(dcx, span, E0123, "msg");  // constant

\#[diag(name, code = E0123)]  // constant
struct Diag;
```

The commit also changes the structure of the error code definitions:
- `rustc_error_codes` now just defines a higher-order macro listing the
  used error codes and nothing else.
- Because that's now the only thing in the `rustc_error_codes` crate, I
  moved it into the `lib.rs` file and removed the `error_codes.rs` file.
- `rustc_errors` uses that macro to define everything, e.g. the error
  code constants and the `DIAGNOSTIC_TABLES`. This is in its new
  `codes.rs` file.
2024-01-29 07:41:41 +11:00
..
src Stop using String for error codes. 2024-01-29 07:41:41 +11:00
Cargo.toml Stop using String for error codes. 2024-01-29 07:41:41 +11:00
messages.ftl Stop telling people to submit bugs for internal feature ICEs 2023-10-25 23:23:04 +02:00
README.md Rename rustc_driver to rustc_driver_impl 2023-02-02 07:12:10 +01:00

The driver crate is effectively the "main" function for the rust compiler. It orchestrates the compilation process and "knits together" the code from the other crates within rustc. This crate itself does not contain any of the "main logic" of the compiler (though it does have some code related to pretty printing or other minor compiler options).

For more information about how the driver works, see the rustc dev guide.