The algorithm implemented here is linear in the size of the two b-trees. It
firsts creates a `MergeIter` from the two b-trees and then builds a new b-tree
by pushing key-value pairs from the `MergeIter` into nodes at the right heights.
Three functions for stealing have been added to the implementation of `Handle` as
well as a getter for the height of a `NodeRef`.
The docs have been updated with performance information about `BTreeMap::append` and
the remark about B has been removed now that it is the same for all instances of `BTreeMap`.
Split core::iter module implementation into parts
Split core::iter module implementation into parts
split iter.rs into a directory of (implementation private) modules.
+ mod (adaptor structs whose private fields need to be available both for them and Iterator
+ iterator (Iterator trait)
+ traits (FromIterator, etc; all traits but Iterator itself)
+ range (range related)
+ sources (Repeat, Once, Empty)
rustdoc: Fix the strip-hidden `ImplStripper`
Instead of stripping impls which reference *stripped* items, we keep impls which reference *retained* items. We do this because when we strip an item we immediately return, and do not recurse into it - leaving the contained items non-stripped from the point of view of the `ImplStripper`.
fixes#33069
r? @alexcrichton
MIR: Do not require END_BLOCK to always exist
Basically, all this does, is removing restriction for END_BLOCK to exist past the first invocation of RemoveDeadBlocks pass. This way for functions whose CFG does not reach the `END_BLOCK` end up not containing the block.
As far as the implementation goes, I’m not entirely satisfied with the `BasicBlock::end_block`. I had hoped to make `new` a `const fn` and then just have a `const END_BLOCK` private to mir::build, but it turns out that constant functions don’t yet support conditionals nor a way to assert.
rustbuild: Package librustc & co for cross-hosts
Currently the `rust-std` package produced by rustbuild only contains the
standard library plus libtest, but the makefiles actually produce a `rust-std`
package with all known target libraries (including libsyntax, librustc, etc).
Tweak the behavior so the dependencies of the `dist-docs` step in rustbuild
depend on the compiler libraries as well (so that they're all packaged).
Closes#32984
doc: Update our tier support
This modifies our listing of tiered platforms a few ways:
* All lists are alphabetized based on target now
* Lots of targets are moved up to "Tier 2" as we're gating on all these builds
and official releases are provided (and installable via rustup).
* A few targets now list having a compiler + cargo now as well.
No more platforms have been moved up to Tier 1 at this time, however. The only
real candidate is ``x86_64-unknown-linux-musl`, but that's not *quite* to a tier
1 level of quality just yet so let's hold off for another release or so to iron
it out a bit.
Compute `target_feature` from LLVM
This is a work-in-progress fix for #31662.
The logic that computes the target features from the command line has been replaced with queries to the `TargetMachine`.
Compute LLVM-agnostic type layouts in rustc.
Layout for monomorphic types, and some polymorphic ones (e.g. `&T` where `T: Sized`),
can now be computed by rustc without involving LLVM in the actual process.
This gives rustc the ability to evaluate `size_of` or `align_of`, as well as obtain field offsets.
MIR-based CTFE will eventually make use of these layouts, as will MIR trans, shortly.
Layout computation also comes with a `[breaking-change]`, or two:
* `"data-layout"` is now mandatory in custom target specifications, reverting the decision from #27076.
This string is needed because it describes endianness, pointer size and alignments for various types.
We have the first two and we could allow tweaking alignments in target specifications.
Or we could also extract the data layout from LLVM and feed it back into rustc.
However, that can vary with the LLVM version, which is fragile and undermines stability.
For built-in targets, I've added a check that the hardcoded data-layout matches LLVM defaults.
* `transmute` calls are checked in a stricter fashion, which fixes#32377
To expand on `transmute`, there are only 2 allowed patterns: between types with statically known sizes and between pointers with the same potentially-unsized "tail" (which determines the type of unsized metadata they use, if any).
If you're affected, my suggestions are:
* try to use casts (and raw pointer deref) instead of transmutes
* *really* try to avoid `transmute` where possible
* if you have a structure, try working on individual fields and unpack/repack the structure instead of transmuting it whole, e.g. `transmute::<RefCell<Box<T>>, RefCell<*mut T>>(x)` doesn't work, but `RefCell::new(Box::into_raw(x.into_inner()))` does (and `Box::into_raw` is just a `transmute`)
mk: Bootstrap from stable instead of snapshots
This commit removes all infrastructure from the repository for our so-called
snapshots to instead bootstrap the compiler from stable releases. Bootstrapping
from a previously stable release is a long-desired feature of distros because
they're not fans of downloading binary stage0 blobs from us. Additionally, this
makes our own CI easier as we can decommission all of the snapshot builders and
start having a regular cadence to when we update the stage0 compiler.
A new `src/etc/get-stage0.py` script was added which shares some code with
`src/bootstrap/bootstrap.py` to read a new file, `src/stage0.txt`, which lists
the current stage0 compiler as well as cargo that we bootstrap from. This script
will download the relevant `rustc` package an unpack it into `$target/stage0` as
we do today.
One problem of bootstrapping from stable releases is that we're not able to
compile unstable code (e.g. all the `#![feature]` directives in libcore/libstd).
To overcome this we employ two strategies:
* The bootstrap key of the previous compiler is hardcoded into `src/stage0.txt`
(enabled as a result of #32731) and exported by the build system. This enables
nightly features in the compiler we download.
* The standard library and compiler are pinned to a specific stage0, which
doesn't change, so we're guaranteed that we'll continue compiling as we start
from a known fixed source.
The process for making a release will also need to be tweaked now to continue to
cadence of bootstrapping from the previous release. This process looks like:
1. Merge `beta` to `stable`
2. Produce a new stable compiler.
3. Change `master` to bootstrap from this new stable compiler.
4. Merge `master` to `beta`
5. Produce a new beta compiler
6. Change `master` to bootstrap from this new beta compiler.
Step 3 above should involve very few changes as `master` was previously
bootstrapping from `beta` which is the same as `stable` at that point in time.
Step 6, however, is where we benefit from removing lots of `#[cfg(stage0)]` and
get to use new features. This also shouldn't slow the release too much as steps
1-5 requires little work other than waiting and step 6 just needs to happen at
some point during a release cycle, it's not time sensitive.
Closes#29555Closes#29557
Assert that the feature strings are NUL terminated, so that they will
be well-formed as C strings.
This is a safety check to ease the maintaninace and update of the
feature lists.
rustbuild: Fix --enable-rpath usage
This commit fixes the `--enable-rpath` configure flag in rustbuild to work
despite the compile-time directories being different than the runtime
directories. This unfortunately means that we can't use `-C rpath` out of the
box but hopefully the portability story here isn't too bad as
`src/librustc_back/rpath.rs` isn't *too* complicated.
Closes#32886
Improve computation of offset in `EscapeUnicode`
Unify the computation of `offset` and use `leading_zeros` instead of manually scanning the bits.
This PR removes some duplicated code and makes it a little simpler .
The computation of `offset` is also faster, but it is unlikely to have an impact on actual code.
(split from #31049)
This test checks that all of the x86 architectures (both `x86` and
`x86_64`) have the `sse2` feature. This is currently true for all of
the targets whose target CPU is `pentium4` (or better), but it might
fail on other targets (for example on `i586`).
This commit removes all infrastructure from the repository for our so-called
snapshots to instead bootstrap the compiler from stable releases. Bootstrapping
from a previously stable release is a long-desired feature of distros because
they're not fans of downloading binary stage0 blobs from us. Additionally, this
makes our own CI easier as we can decommission all of the snapshot builders and
start having a regular cadence to when we update the stage0 compiler.
A new `src/etc/get-stage0.py` script was added which shares some code with
`src/bootstrap/bootstrap.py` to read a new file, `src/stage0.txt`, which lists
the current stage0 compiler as well as cargo that we bootstrap from. This script
will download the relevant `rustc` package an unpack it into `$target/stage0` as
we do today.
One problem of bootstrapping from stable releases is that we're not able to
compile unstable code (e.g. all the `#![feature]` directives in libcore/libstd).
To overcome this we employ two strategies:
* The bootstrap key of the previous compiler is hardcoded into `src/stage0.txt`
(enabled as a result of #32731) and exported by the build system. This enables
nightly features in the compiler we download.
* The standard library and compiler are pinned to a specific stage0, which
doesn't change, so we're guaranteed that we'll continue compiling as we start
from a known fixed source.
The process for making a release will also need to be tweaked now to continue to
cadence of bootstrapping from the previous release. This process looks like:
1. Merge `beta` to `stable`
2. Produce a new stable compiler.
3. Change `master` to bootstrap from this new stable compiler.
4. Merge `master` to `beta`
5. Produce a new beta compiler
6. Change `master` to bootstrap from this new beta compiler.
Step 3 above should involve very few changes as `master` was previously
bootstrapping from `beta` which is the same as `stable` at that point in time.
Step 6, however, is where we benefit from removing lots of `#[cfg(stage0)]` and
get to use new features. This also shouldn't slow the release too much as steps
1-5 requires little work other than waiting and step 6 just needs to happen at
some point during a release cycle, it's not time sensitive.
Closes#29555Closes#29557
The different generations of ARM floating point VFP correspond to the
LLVM CPU features named `vfp2`, `vfp3`, and `vfp4`; they are now
exposed in Rust under the same names.
This commit fixes some crashes that would occour when checking if the
`vfp` feature exists (the crash occurs because the linear scan of the
LLVM feature goes past the end of the features whenever it searches
for a feature that does not exist in the LLVM tables).
rustdoc: refine cross-crate impl inlining
This changes the current rule that impls within `doc(hidden)` modules aren't inlined, to only inlining impls where the implemented trait and type are reachable in documentation.
fixes#14586fixes#31948
.. and also applies the reachability checking to cross-crate links.
fixes#28480
r? @alexcrichton
rustbuild: Add support for compiletest test suites
This commit adds support in rustbuild for running all of the compiletest test
suites as part of `make check`. The `compiletest` program was moved to
`src/tools` (like `rustbook` and others) and is now just compiled like any other
old tool. Each test suite has a pretty standard set of dependencies and just
tweaks various parameters to the final compiletest executable.
Note that full support is lacking in terms of:
* Once a test suite has passed, that's not remembered. When a test suite is
requested to be run, it's always run.
* The arguments to compiletest probably don't work for every possible
combination of platforms and testing environments just yet. There will likely
need to be future updates to tweak various pieces here and there.
* Cross compiled test suites probably don't work just yet, support for that will
come in a follow-up patch.
This commit adds support in rustbuild for running all of the compiletest test
suites as part of `make check`. The `compiletest` program was moved to
`src/tools` (like `rustbook` and others) and is now just compiled like any other
old tool. Each test suite has a pretty standard set of dependencies and just
tweaks various parameters to the final compiletest executable.
Note that full support is lacking in terms of:
* Once a test suite has passed, that's not remembered. When a test suite is
requested to be run, it's always run.
* The arguments to compiletest probably don't work for every possible
combination of platforms and testing environments just yet. There will likely
need to be future updates to tweak various pieces here and there.
* Cross compiled test suites probably don't work just yet, support for that will
come in a follow-up patch.
grammar: fix
Reading this, one item stood out a bit. Small improvements here.
1. ‘Compile-time’ is not a noun, ‘compilation time’ was meant;
1. Mathematical formulas are best not rendered as code;
1. Use the same tense as in other items.
Reword explanation of 'size' types.
Do not reference machine 'pointers' in explanation of 'size' types.
I think the number of elements that can be directly addressed is a fundamental feature of a machine architecture in its own right. The fact that it coincides with the ‘size’ of a pointer should be viewed as an ‘implementation detail’ ;)
split iter.rs into a directory of (implementation private) modules.
+ mod Adaptor structs
- Private fields need to be available both for them and Iterator
+ iterator (Iterator trait)
+ traits (FromIterator, traits but Iterator itself)
+ range (range related)
+ sources (Repeat, Once, Empty)
rustbuild: Clean more as part of `make clean`
Clean out old documentation as well as the new test/tools directories. Should
prevent a problem that happened this morning where a PR bounced and then it left
docs with "broken links" so all future PRs bounced.
Instead of stripping impls which reference *stripped* items, we keep impls
which reference *retained* items. We do this because when we strip an
item we immediately return, and do not recurse into it - leaving the
contained items non-stripped from the point of view of the `ImplStripper`.
resolve: Improve performance
This fixes#33061 by speeding up searchs through all traits in scope, a bottleneck in `resolve`.
According to my measurements, this PR improves resolution performance by a factor of 3.4x on `librustc`, which almost completely reverses the 3.75x performance regression reported in #33061.
r? @eddyb
This changes the current rule that impls within `doc(hidden)` modules
aren't inlined, to only inlining impls where the implemented
trait and type are reachable in documentation.
