Create a directory for --out-dir if it does not already exist
Currently if `--out-dir` is set to a non-existent directory, the compiler will throw unfriendly messages like `error: could not write output to subdir/example.crate.allocator.rcgu.o: No such file or
directory`, which, while not completely unreadable, isn’t very user-friendly either. This change creates the directory automatically if it does not yet exist.
rustc: Upgrade to LLVM 6
The following submodules have been updated for a new version of LLVM:
- `src/llvm`
- `src/libcompiler_builtins` - transitively contains compiler-rt
- `src/dlmalloc`
This also updates the docker container for dist-i686-freebsd as the old 16.04
container is no longer capable of building LLVM. The
compiler-rt/compiler-builtins and dlmalloc updates are pretty routine without
much interesting happening, but the LLVM update here is of particular note.
Unlike previous updates I haven't cherry-picked all existing patches we had on
top of our LLVM branch as we have a [huge amount][patches4] and have at this
point forgotten what most of them are for. Instead I started from the current
`release_60` branch in LLVM and only applied patches that were necessary to get
our tests working and building.
The [current set of custom rustc-specific patches](f1286127b7...rust-llvm-release-6-0-0) included in this LLVM update are:
* rust-lang/llvm@1187443 - this is how we actually implement
`cfg(target_feature)` for now and continues to not be upstreamed. While a
hazard for SIMD stabilization this commit is otherwise keeping the status
quo of a small rustc-specific feature.
* rust-lang/llvm@013f2ec - this is a rustc-specific optimization that we haven't
upstreamed, notably teaching LLVM about our allocation-related routines (which
aren't malloc/free). Once we stabilize the global allocator routines we will
likely want to upstream this patch, but for now it seems reasonable to keep it
on our fork.
* rust-lang/llvm@a65bbfd - I found this necessary to fix compilation of LLVM in
our 32-bit linux container. I'm not really sure why it's necessary but my
guess is that it's because of the absolutely ancient glibc that we're using.
In any case it's only updating pieces we're not actually using in LLVM so I'm
hoping it'll turn out alright. This doesn't seem like something we'll want to
upstream.c
* rust-lang/llvm@77ab1f0 - this is what's actually enabling LLVM to build in our
i686-freebsd container, I'm not really sure what's going on but we for sure
probably don't want to upstream this and otherwise it seems not too bad for
now at least.
* rust-lang/llvm@9eb9267 - we currently suffer on MSVC from an [upstream bug]
which although diagnosed to a particular revision isn't currently fixed
upstream (and the bug itself doesn't seem too active). This commit is a
partial revert of the suspected cause of this regression (found via a
bisection). I'm sort of hoping that this eventually gets fixed upstream with a
similar fix (which we can replace in our branch), but for now I'm also hoping
it's a relatively harmless change to have.
After applying these patches (plus one [backport] which should be [backported
upstream][llvm-back]) I believe we should have all tests working on all
platforms in our current test suite. I'm like 99% sure that we'll need some more
backports as issues are reported for LLVM 6 when this propagates through
nightlies, but that's sort of just par for the course nowadays!
In any case though some extra scrutiny of the patches here would definitely be
welcome, along with scrutiny of the "missing patches" like a [change to pass
manager order](rust-lang/llvm@2717444), [another change to pass manager
order](rust-lang/llvm@c782feb), some [compile fixes for
sparc](rust-lang/llvm@1a83de6), and some [fixes for
solaris](rust-lang/llvm@c2bfe0a).
[patches4]: rust-lang/llvm@5401fdf...rust-llvm-release-4-0-1
[backport]: rust-lang/llvm@5c54c25
[llvm-back]: https://bugs.llvm.org/show_bug.cgi?id=36114
[upstream bug]: https://bugs.llvm.org/show_bug.cgi?id=36096
---
The update to LLVM 6 is desirable for a number of reasons, notably:
* This'll allow us to keep up with the upstream wasm backend, picking up new
features as they start landing.
* Upstream LLVM has fixed a number of SIMD-related compilation errors,
especially around AVX-512 and such.
* There's a few assorted known bugs which are fixed in LLVM 5 and aren't fixed
in the LLVM 4 branch we're using.
* Overall it's not a great idea to stagnate with our codegen backend!
This update is mostly powered by #47730 which is allowing us to update LLVM
*independent* of the version of LLVM that Emscripten is locked to. This means
that when compiling code for Emscripten we'll still be using the old LLVM 4
backend, but when compiling code for any other target we'll be using the new
LLVM 6 target. Once Emscripten updates we may no longer need this distinction,
but we're not sure when that will happen!
Closes#43370Closes#43418Closes#47015Closes#47683Closesrust-lang-nursery/stdsimd#157Closesrust-lang-nursery/rust-wasm#3
The following submodules have been updated for a new version of LLVM:
- `src/llvm`
- `src/libcompiler_builtins` - transitively contains compiler-rt
- `src/dlmalloc`
This also updates the docker container for dist-i686-freebsd as the old 16.04
container is no longer capable of building LLVM. The
compiler-rt/compiler-builtins and dlmalloc updates are pretty routine without
much interesting happening, but the LLVM update here is of particular note.
Unlike previous updates I haven't cherry-picked all existing patches we had on
top of our LLVM branch as we have a [huge amount][patches4] and have at this
point forgotten what most of them are for. Instead I started from the current
`release_60` branch in LLVM and only applied patches that were necessary to get
our tests working and building.
The current set of custom rustc-specific patches included in this LLVM update are:
* rust-lang/llvm@1187443 - this is how we actually implement
`cfg(target_feature)` for now and continues to not be upstreamed. While a
hazard for SIMD stabilization this commit is otherwise keeping the status
quo of a small rustc-specific feature.
* rust-lang/llvm@013f2ec - this is a rustc-specific optimization that we haven't
upstreamed, notably teaching LLVM about our allocation-related routines (which
aren't malloc/free). Once we stabilize the global allocator routines we will
likely want to upstream this patch, but for now it seems reasonable to keep it
on our fork.
* rust-lang/llvm@a65bbfd - I found this necessary to fix compilation of LLVM in
our 32-bit linux container. I'm not really sure why it's necessary but my
guess is that it's because of the absolutely ancient glibc that we're using.
In any case it's only updating pieces we're not actually using in LLVM so I'm
hoping it'll turn out alright. This doesn't seem like something we'll want to
upstream.c
* rust-lang/llvm@77ab1f0 - this is what's actually enabling LLVM to build in our
i686-freebsd container, I'm not really sure what's going on but we for sure
probably don't want to upstream this and otherwise it seems not too bad for
now at least.
* rust-lang/llvm@9eb9267 - we currently suffer on MSVC from an [upstream bug]
which although diagnosed to a particular revision isn't currently fixed
upstream (and the bug itself doesn't seem too active). This commit is a
partial revert of the suspected cause of this regression (found via a
bisection). I'm sort of hoping that this eventually gets fixed upstream with a
similar fix (which we can replace in our branch), but for now I'm also hoping
it's a relatively harmless change to have.
After applying these patches (plus one [backport] which should be [backported
upstream][llvm-back]) I believe we should have all tests working on all
platforms in our current test suite. I'm like 99% sure that we'll need some more
backports as issues are reported for LLVM 6 when this propagates through
nightlies, but that's sort of just par for the course nowadays!
In any case though some extra scrutiny of the patches here would definitely be
welcome, along with scrutiny of the "missing patches" like a [change to pass
manager order](rust-lang/llvm@2717444753), [another change to pass manager
order](rust-lang/llvm@c782febb7b), some [compile fixes for
sparc](rust-lang/llvm@1a83de63c4), and some [fixes for
solaris](rust-lang/llvm@c2bfe0abb).
[patches4]: https://github.com/rust-lang/llvm/compare/5401fdf23...rust-llvm-release-4-0-1
[backport]: https://github.com/rust-lang/llvm/commit/5c54c252db
[llvm-back]: https://bugs.llvm.org/show_bug.cgi?id=36114
[upstream bug]: https://bugs.llvm.org/show_bug.cgi?id=36096
---
The update to LLVM 6 is desirable for a number of reasons, notably:
* This'll allow us to keep up with the upstream wasm backend, picking up new
features as they start landing.
* Upstream LLVM has fixed a number of SIMD-related compilation errors,
especially around AVX-512 and such.
* There's a few assorted known bugs which are fixed in LLVM 5 and aren't fixed
in the LLVM 4 branch we're using.
* Overall it's not a great idea to stagnate with our codegen backend!
This update is mostly powered by #47730 which is allowing us to update LLVM
*independent* of the version of LLVM that Emscripten is locked to. This means
that when compiling code for Emscripten we'll still be using the old LLVM 4
backend, but when compiling code for any other target we'll be using the new
LLVM 6 target. Once Emscripten updates we may no longer need this distinction,
but we're not sure when that will happen!
Closes#43370Closes#43418Closes#47015Closes#47683Closesrust-lang-nursery/stdsimd#157Closesrust-lang-nursery/rust-wasm#3
Right now the `--build` option was accidentally omitted, so we're bootstraping
from `x86_64` to `i686`. In addition to being slower (more compiles) that's not
actually bootstrapping!
[NLL] Add false edges out of infinite loops
Resolves#46036 by adding a `cleanup` member to the `FalseEdges` terminator kind. There's also a small doc fix to one of the other comments in `into.rs` which I can pull out in to another PR if desired =)
This PR should pass CI but the test suite has been relatively unstable on my system so I'm not 100% sure.
r? @nikomatsakis
During the RFC, it was discussed that figuring out whether a range is empty was subtle, and thus there should be a clear and obvious way to do it. It can't just be ExactSizeIterator::is_empty (also unstable) because not all ranges are ExactSize -- not even Range<i32> or RangeInclusive<usize>.
NLL: Limit two-phase borrows to autoref-introduced borrows
This imposes a restriction on two-phase borrows so that it only applies to autoref-introduced borrows.
The goal is to ensure that our initial deployment of two-phase borrows is very conservative. We want it to still cover the `v.push(v.len());` example, but we do not want it to cover cases like `let imm = &v; let mu = &mut v; mu.push(imm.len());`
(Why do we want it to be conservative? Because when you are not conservative, then the results you get, at least with the current analysis, are tightly coupled to details of the MIR construction that we would rather remain invisible to the end user.)
Fix#46747
I decided, for this PR, to add a debug-flag `-Z two-phase-beyond-autoref`, to re-enable the more general approach. But my intention here is *not* that we would eventually turn on that debugflag by default; the main reason I added it was that I thought it was useful for writing tests to be able to write source that looks like desugared MIR.
Right now the ccache setting is only used for LLVM, but this tweaks it to also
be used for build scripts so C++ builds like `librustc_llvm` can be a bit
speedier.
This commit disallows acquiring a function pointer to functions tagged as
`#[rustc_args_required_const]`. This is intended to be used as future-proofing
for the stdsimd crate to avoid taking a function pointer to any intrinsic which
has a hard requirement that one of the arguments is a constant value.
Unfortunately left out it means that when the `#![feature(proc_macro)]` flag is
in effect it fails to find `rustc_args_required_const` for expansion. This
version, however, is verified to work with stdsimd's requirements!
The x86_64 SysV ABI should use exact sizes for small structs passed in
registers, i.e. a struct that occupies 3 bytes should use an i24,
instead of the i32 it currently uses.
Refs #45543
Namely, the mutable borrows also carries a flag indicating whether
they should support two-phase borrows.
This allows us to thread down, from the point of the borrow's
introduction, whether the particular adjustment that created it is one
that yields two-phase mutable borrows.
Added `-Z two-phase-beyond-autoref` to bring back old behavior (mainly
to allow demonstration of desugared examples).
Updated tests to use aforementioned flag when necessary. (But in each
case where I added the flag, I made sure to also include a revision
without the flag so that one can readily see what the actual behavior
we expect is for the initial deployment of NLL.)
