Move `DIAGNOSTICS` usage to `rustc_driver`
Remove `rustc_interface`'s dependency on `rustc_error_codes` and centralize all usages of `DIAGNOSTICS` in `rustc_driver`. Once we remove all references to `rustc_error_codes` in all other crates but `rustc_driver`, this should allow for incremental recompilation of the compiler to be smoother when tweaking error codes. This works towards https://github.com/rust-lang/rust/issues/66210#issuecomment-551862528.
(May include traces of minor drive-by cleanup.)
r? @Mark-Simulacrum
Centralize panic macro documentation
This is just the main commit from #61511 (which got closed because the author didn't reply) cherry-picked on the current master. Building `core` and `std` on this branch in stage 1 succeeded, which I thinks means the issues from the previous PR should be gone (but let's see what CI says).
rustc_plugin: Remove `Registry::register_attribute`
Legacy plugins cannot register inert attributes anymore.
The preferred replacement is to use `register_tool` ([tracking issue](https://github.com/rust-lang/rust/issues/66079)).
```rust
#![register_tool(servo)]
#[servo::must_root]
struct S;
```
The more direct replacement is `register_attribute` ([tracking issue](https://github.com/rust-lang/rust/issues/66080))
```rust
#![register_attr(must_root)]
#[must_root]
struct S;
```
, but it requires registering each attribute individually rather than registering the tool once, and is more likely to be removed rather than stabilized.
Improve documentation of `Vec::split_off(...)`
The previous ordering of the sentences kept switching between the return
value and the value of `self` after execution, making it hard to follow.
Additionally, as rendered in the browser, the period in "`Self`. `self`"
was difficult to make out as being a sentence separator and not one code
block.
The previous ordering of the sentences kept switching between the return
value and the value of `self` after execution, making it hard to follow.
Additionally, as rendered in the browser, the period in "`Self`. `self`"
was difficult to make out as being a sentence separator and not one code
block.
Fully integrate derive helpers into name resolution
```rust
#[derive(Foo)]
#[foo_helper] // already goes through name resolution
struct S {
#[foo_helper] // goes through name resolution after this PR
field: u8
}
```
How name resolution normally works:
- We have an identifier we need to resolve, take its location (in some sense) and look what names are in scope in that location.
How derive helper attributes are "resolved" (before this PR):
- After resolving the derive `Foo` we visit the derive's input (`struct S { ... } `) as a piece of AST and mark attributes textually matching one of the derive's helper attributes (`foo_helper`) as "known", so they never go through name resolution.
This PR changes the rules for derive helpers, so they are not proactively marked as known (which is a big hack ignoring any ambiguities or hygiene), but go through regular name resolution instead.
This change was previously blocked by attributes not being resolved in some positions at all (fixed in https://github.com/rust-lang/rust/pull/63468).
"Where exactly are derive helpers in scope?" is an interesting question, and I need some feedback from proc macro authors to answer it, see the post below (https://github.com/rust-lang/rust/pull/64694#issuecomment-533925160).
These helpers are resolved before their respective derives through a kind of look ahead into future expansions.
Some of these will migrate to proper resolution, others will be deprecated.
```
#[trait_helper] // Deprecate
#[derive(Trait)]
#[trait_helper] // Migrate to proper resolution
```
Update cc, git2, num_cpus.
This updates the `cc` crate, bringing in better parallel building support. Also updates `git2` which enables the parallel feature. (Note: I don't expect it will have a significant impact on build time, but seems good to update anyways.)
The main thorn is that `cc` gained knowledge about RISC-V architectures (https://github.com/alexcrichton/cc-rs/pull/428, https://github.com/alexcrichton/cc-rs/pull/429, https://github.com/alexcrichton/cc-rs/pull/430), but the builders on CI do not have the riscv C compiler installed. This means that bootstraps' cc detection was finding a C compiler that isn't installed, and fails.
The solution here is to override the cc detection to `false`. The C compiler isn't actually used on riscv platforms. AFAIK, the only location would be compiler_builtins, and it currently forces C support off (a533ae9c5a/build.rs (L49-L55)).
Other possible solutions:
- Add the override in cc_detect for riscv (or any "no-C" platform like wasm32 and nvptx)
- Install and use the appropriate c compiler. I tried this the `g++-riscv64-linux-gnu` package, but it failed missing some header file.
Closes#66232
Rollup of 5 pull requests
Successful merges:
- #66350 (protect creation of destructors by a mutex)
- #66407 (Add more tests for fixed ICEs)
- #66415 (Add --force-run-in-process unstable option to libtest)
- #66427 (Move the JSON error emitter to librustc_errors)
- #66441 (libpanic_unwind for Miri: make sure we have the SEH lang items when needed)
Failed merges:
r? @ghost
Refactor integer range handling in the usefulness algorithm
Integer range handling had accumulated a lot of debt. This cleans up a lot of it.
In particular this:
- removes unnecessary conversions between `Const` and `u128`, and between `Constructor` and `IntRange`
- clearly distinguishes between on the one hand ranges of integers that may or may not be matched exhaustively, and on the other hand ranges of non-integers that are never matched exhaustively and are compared using Const-based shenanigans
- cleans up some overly complicated code paths
- generally tries to be more idiomatic.
As a nice side-effect, I measured a 10% perf increase on `unicode_normalization`.
There's one thing that I feel remains to clean up: the [overlapping range check](https://github.com/rust-lang/rust/pull/64007), which is currently quite ad-hoc. But that is intricate enough that I'm leaving it out of this PR.
There's also one little thing I'm not sure I understand: can `try_eval_bits` fail for an integer constant value in that code ? What would that mean, and how do I construct a test case for this possibility ?
libpanic_unwind for Miri: make sure we have the SEH lang items when needed
r? @oli-obk @alexcrichton This is required to fix the Miri toolstate. Turns out rustc complains when doing codegen for MSVC and these lang items do not exist. For now `cfg(miri)` needs to still be able to codegen (we [plan to change that](https://github.com/rust-lang/miri/pull/1048#issuecomment-554108470) but that's a larger project requiring improvements to xargo and maybe also cargo; that should not block fixing the toolstate). Yes, this is a hack, but it is inside `cfg(miri)` so I hope this is okay.
Cc @Aaron1011
Move the JSON error emitter to librustc_errors
This is done both as a cleanup (it makes little sense for this emitter to be in libsyntax), but also as part of broader work to decouple Session from librustc itself.
Along the way, this also moves SourceMap to syntax_pos, which is also nice for the above reasons, as well as allowing dropping the SourceMapper trait from code. This had the unfortunate side-effect of moving `FatalError` to rustc_data_structures (it's needed in syntax_pos, due to SourceMap, but putting it there feels somehow worse).
Add --force-run-in-process unstable option to libtest
When running tests with `-Zpanic_abort_tests`, it's sometimes desirable to fall back to the old behavior of only running tests in-process. This comes in handy if the system process launcher is unavailable, or the test code somehow expects all tests to be run in the same process.
For example, in Fuchsia we have unit tests that actually test the process launcher itself, in which case we can't use the process launcher to run the tests :).
r? @alexcrichton
cc @cramertj,@petrhosek
Add more tests for fixed ICEs
Closes#36122 (fixed in 1.20.0)
Closes#58094 (fixed in #66054)
Also, fix mistaken test case, from #30904 to #30906 (cc @eddyb)
r? @Centril
That condition was leftover from a refactor, and was probably not
intended. In fact it can't trigger: it would require a ConstantValue of
an integral type for which `try_eval_bits` fails. But since we only
apply `subtract_ctors` to the output of `all_ctors`, this won't happen.
