Copy more libraries from local Rust to stage0
When bootstrapping Rust using a previously built toolchain, I noticed
a number of libraries were not copied in. As a result the copied in
rustc fails to execute because it can't find all its dependences.
Add them into the local_stage0.sh script.
Explain the meaning of the fields of the control word and provide more
details about how the relevant one (Precision Control) is updated in
the fast path.
The fast path of the float parser relies on the rounding to happen
exactly and directly to the correct number of bits. On x87, instead,
double rounding would occour as the FPU stack defaults to 80 bits of
precision.
This can be fixed by setting the precision of the FPU stack before
performing the int to float conversion. This can be achieved by
changing the value of the x87 control word. This is a somewhat common
operation that is in fact performed whenever a float needs to be
truncated to an integer, but it is undesirable to add its overhead for
code that does not rely on x87 for computations (i.e. on non-x86
architectures, or x86 architectures which perform FPU computations on
using SSE).
Fixes `num::dec2flt::fast_path_correct` (on x87).
mir: don't attempt to promote Unpromotable constant temps.
Fixes#33537. This was a non-problem in regular functions, but we also promote in `const fn`s.
There we always qualify temps so you can't depend on `Unpromotable` temps being `NOT_CONST`.
re-introduce a cache for ast-ty-to-ty
It turns out that `ast_ty_to_ty` is supposed to be updating the `def`
after it finishes, but at some point in the past it stopped doing
so. This was never noticed because of the `ast_ty_to_ty_cache`, but that
cache was recently removed. This PR fixes the code to update the def
properly, but apparently that is not quite enough to make the operation
idempotent, so for now we reintroduce the cache too.
Fixes#33586.
r? @eddyb
Make --emit dep-info work correctly with -Z no-analysis again.
Previously, it would attempt to resolve some external crates that weren't necessary for dep-info output.
Fixes#33231.
When using closures that take references with explicit lifetimes sometimes
it's required to use where F: for<..> ... syntax to express the right
lifetimes. This adds a quick note to the docs so other users can discover
it as well.
In short, this PR changes the MIR printer so that it:
* places an empty line between the MIR for each item
* does *not* write an empty line before the first BB when there are no
var decls
* aligns the "// Scope" comments 50 chars in (makes the output more
readable)
* prints the scope comments as "// scope N at ..." instead of "//
Scope(N) at ..."
* prints a prettier scope tree:
* no more unbalanced delimiters!
* no more "Parent" entry (these convey no useful information)
* drop the "Scope()" and just print scope IDs
* no braces when the scope is empty
rustbuild: Add support for crate tests + doctests
This commit adds support to rustbuild to run crate unit tests (those defined by
`#[test]`) as well as documentation tests. All tests are powered by `cargo test`
under the hood.
Each step requires the `libtest` library is built for that corresponding stage.
Ideally the `test` crate would be a dev-dependency, but for now it's just easier
to ensure that we sequence everything in the right order.
Currently no filtering is implemented, so there's not actually a method of
testing *only* libstd or *only* libcore, but rather entire swaths of crates are
tested all at once.
A few points of note here are:
* The `coretest` and `collectionstest` crates are just listed as `[[test]]`
entires for `cargo test` to naturally pick up. This mean that `cargo test -p
core` actually runs all the tests for libcore.
* Libraries that aren't tested all mention `test = false` in their `Cargo.toml`
* Crates aren't currently allowed to have dev-dependencies due to
rust-lang/cargo#860, but we can likely alleviate this restriction once
workspaces are implemented.
cc #31590
A number of trait methods like PartialEq::eq or Hash::hash don't
actually need a distinct arm for each variant, because the code within
the arm only depends on the number and types of the fields in the
variants. We can easily exploit this fact to create less and better
code for enums with multiple variants that have no fields at all, the
extreme case being C-like enums.
For nickel.rs and its by now infamous 800 variant enum, this reduces
optimized compile times by 25% and non-optimized compile times by 40%.
Also peak memory usage is down by almost 40% (310MB down to 190MB).
To be fair, most other crates don't benefit nearly as much, because
they don't have as huge enums. The crates in the Rust distribution that
I measured saw basically no change in compile times (I only tried
optimized builds) and only 1-2% reduction in peak memory usage.
It turns out that `ast_ty_to_ty` is supposed to be updating the `def`
after it finishes, but at some point in the past it stopped doing
so. This was never noticed because of the `ast_ty_to_ty_cache`, but that
cache was recently removed. This PR fixes the code to update the def
properly, but apparently that is not quite enough to make the operation
idempotent, so for now we reintroduce the cache too.
Fixes#33425.
This commit adds support to rustbuild to run crate unit tests (those defined by
`#[test]`) as well as documentation tests. All tests are powered by `cargo test`
under the hood.
Each step requires the `libtest` library is built for that corresponding stage.
Ideally the `test` crate would be a dev-dependency, but for now it's just easier
to ensure that we sequence everything in the right order.
Currently no filtering is implemented, so there's not actually a method of
testing *only* libstd or *only* libcore, but rather entire swaths of crates are
tested all at once.
A few points of note here are:
* The `coretest` and `collectionstest` crates are just listed as `[[test]]`
entires for `cargo test` to naturally pick up. This mean that `cargo test -p
core` actually runs all the tests for libcore.
* Libraries that aren't tested all mention `test = false` in their `Cargo.toml`
* Crates aren't currently allowed to have dev-dependencies due to
rust-lang/cargo#860, but we can likely alleviate this restriction once
workspaces are implemented.
cc #31590
typeck: limit number of candidates shown for a single error
No idea if 10/11 is a good limit. Are there any other such limits in rustc currently?
Fixes: #25356
const_fn: Check the terminating expression of a block for blocks in a const initializer
In a const or static initializer, the `CheckBlock` check ensures that blocks in the initializer expression are only in tail positions or in items. In this case, it didn't check the terminating expression of a block, which resulted in an ICE later in the compiler pipeline if the trailing expression was itself a block. This change fixes the ICE and ensures that the proper error is emitted. This fixes the ICE in #32829 .
