Preparatory refactorings for collector-driven trans.
This is a set of refactorings that allows to do translation item collection and partitioning before LocalCrateContext instances or LLVM modules are generated. As a consequence we can now create LocalCrateContexts already with knowledge of the codegen unit it will be used for. This is a preparation step for driving trans by the results of codegen unit partitioning.
Perform name resolution before and during ast->hir lowering
This PR performs name resolution before and during ast->hir lowering instead of in phase 3.
r? @nrc
rustc: Implement custom panic runtimes
This commit is an implementation of [RFC 1513] which allows applications to
alter the behavior of panics at compile time. A new compiler flag, `-C panic`,
is added and accepts the values `unwind` or `panic`, with the default being
`unwind`. This model affects how code is generated for the local crate, skipping
generation of landing pads with `-C panic=abort`.
[RFC 1513]: https://github.com/rust-lang/rfcs/blob/master/text/1513-less-unwinding.md
Panic implementations are then provided by crates tagged with
`#![panic_runtime]` and lazily required by crates with
`#![needs_panic_runtime]`. The panic strategy (`-C panic` value) of the panic
runtime must match the final product, and if the panic strategy is not `abort`
then the entire DAG must have the same panic strategy.
With the `-C panic=abort` strategy, users can expect a stable method to disable
generation of landing pads, improving optimization in niche scenarios,
decreasing compile time, and decreasing output binary size. With the `-C
panic=unwind` strategy users can expect the existing ability to isolate failure
in Rust code from the outside world.
Organizationally, this commit dismantles the `sys_common::unwind` module in
favor of some bits moving part of it to `libpanic_unwind` and the rest into the
`panicking` module in libstd. The custom panic runtime support is pretty similar
to the custom allocator support with the only major difference being how the
panic runtime is injected (takes the `-C panic` flag into account).
Closes#32837
Currently the compiler has two relatively critical bugs in the implementation of
MSVC unwinding:
* #33112 - faults like segfaults and illegal instructions will run destructors
in Rust, meaning we keep running code after a super-fatal exception
has happened.
* #33116 - When compiling with LTO plus `-Z no-landing-pads` (or `-C
panic=abort` with the previous commit) LLVM won't remove all `invoke`
instructions, meaning that some landing pads stick around and
cleanups may be run due to the previous bug.
These both stem from the flavor of "personality function" that Rust uses for
unwinding on MSVC. On 32-bit this is `_except_handler3` and on 64-bit this is
`__C_specific_handler`, but they both essentially are the "most generic"
personality functions for catching exceptions and running cleanups. That is,
thse two personalities will run cleanups for all exceptions unconditionally, so
when we use them we run cleanups for **all SEH exceptions** (include things like
segfaults).
Note that this also explains why LLVM won't optimize away `invoke` instructions.
These functions can legitimately still unwind (the `nounwind` attribute only
seems to apply to "C++ exception-like unwining"). Also note that the standard
library only *catches* Rust exceptions, not others like segfaults and illegal
instructions.
LLVM has support for another personality, `__CxxFrameHandler3`, which does not
run cleanups for general exceptions, only C++ exceptions thrown by
`_CxxThrowException`. This essentially ideally matches our use case, so this
commit moves us over to using this well-known personality function as well as
exception-throwing function.
This doesn't *seem* to pull in any extra runtime dependencies just yet, but if
it does we can perhaps try to work out how to implement more of it in Rust
rather than relying on MSVCRT runtime bits.
More details about how this is actually implemented can be found in the changes
itself, but this...
Closes#33112Closes#33116
rustdoc: do not strip blanket impls in crate of origin
In `impl<T> Trait for T`, the blanket type parameters `T` were recognized as "local" and "not exported", so these impls were thrown out.
Now we check if they are generic, and keep them in that case.
Fixes: #29503
book: fixup code in error handling tutorial
A few oversights happened while porting the example from docopt to getopts. I retraced all the steps, fixing code and description as necessary.
Fixes: #33422
save-analysis: use a decoupled representation for dumped data
Closes#33348
This will probably break any tool relying on the csv backend of save_analysis, for the following reasons:
1. Dumped spans don't contain extents anymore (`Dump` uses `SpanData` now instead of internal `Span`s). In case we still want to dump extents we could add them to `SpanData`.
1. `DefId`s are no longer dumped as a pair of `(ref_id, ref_crate)`. Instead, they are dumped as a single `Id`.
@nrc You said something about storing the id in a `u64`, but you didn't explain why. I kept using `u32` in this branch but I can change it if you prefer that.
r? @nrc
By the way, the fact that this breaks tools relying on CSV may be a good occasion to start dumping CSV in a different way (i.e. using the serializer like in the JSON backend).
std: Allow creating ExitStatus from raw values
Sometimes a process may be waited on externally from the standard library, in
which case it can be useful to create a raw `ExitStatus` structure to return.
This commit extends the existing Unix `ExitStatusExt` extension trait and adds a
new Windows-specific `ExitStatusExt` extension trait to do this. The methods are
currently called `ExitStatus::from_raw`.
cc #32713
std: Allow creating ExitStatus from raw values
Sometimes a process may be waited on externally from the standard library, in
which case it can be useful to create a raw `ExitStatus` structure to return.
This commit extends the existing Unix `ExitStatusExt` extension trait and adds a
new Windows-specific `ExitStatusExt` extension trait to do this. The methods are
currently called `ExitStatus::from_raw`.
cc #32713
Add integer atomic types
Tracking issue: #32976
RFC: rust-lang/rfcs#1543
The changes to AtomicBool in the RFC are not included, they are in a separate PR (#32365).
This commit is an implementation of [RFC 1513] which allows applications to
alter the behavior of panics at compile time. A new compiler flag, `-C panic`,
is added and accepts the values `unwind` or `panic`, with the default being
`unwind`. This model affects how code is generated for the local crate, skipping
generation of landing pads with `-C panic=abort`.
[RFC 1513]: https://github.com/rust-lang/rfcs/blob/master/text/1513-less-unwinding.md
Panic implementations are then provided by crates tagged with
`#![panic_runtime]` and lazily required by crates with
`#![needs_panic_runtime]`. The panic strategy (`-C panic` value) of the panic
runtime must match the final product, and if the panic strategy is not `abort`
then the entire DAG must have the same panic strategy.
With the `-C panic=abort` strategy, users can expect a stable method to disable
generation of landing pads, improving optimization in niche scenarios,
decreasing compile time, and decreasing output binary size. With the `-C
panic=unwind` strategy users can expect the existing ability to isolate failure
in Rust code from the outside world.
Organizationally, this commit dismantles the `sys_common::unwind` module in
favor of some bits moving part of it to `libpanic_unwind` and the rest into the
`panicking` module in libstd. The custom panic runtime support is pretty similar
to the custom allocator support with the only major difference being how the
panic runtime is injected (takes the `-C panic` flag into account).
In `impl<T> Trait for T`, the blanket type parameters `T` were
recognized as "local" and "not exported", so these impls were
thrown out.
Now we check if they are generic, and keep them in that case.
Fixes: #29503
trans: callee: normalize trait_ref before use
This fixes#33436 and #33461. Ran the tests and nothing else seems to be affected.
P.S. How to write the regression test for this fix? Does this qualify as run-pass or run-make, as the test only needs to be successfully compiled to be considered passed? Will add the testcase (the minimal example in #33461 seems fit) after clarifying this.
