Add -mrelax-relocations=no hacks to fix musl build
* this is just a start, dunno if it will work, but I'll just push it out to get feedback (my rust is still building 😢)
* I don't know much about rustbuild, so i just added that flag in there. it's a total hack, don't judge me
* I suspect the places in the musl .mk files are sufficient (but we may also need it present when building std), I'm not sure, needs more testing.
LLVM upgrade
As discussed in https://internals.rust-lang.org/t/need-help-with-emscripten-port/3154/46 I'm trying to update the used LLVM checkout in Rust.
I basically took @shepmaster's code and applied it on top (though I did the commits manually, the [original commits have better descriptions](https://github.com/rust-lang/rust/compare/master...avr-rust:avr-support).
With these changes I was able to build rustc. `make check` throws one last error on `run-pass/issue-28950.rs`. Output: https://gist.github.com/badboy/bcdd3bbde260860b6159aa49070a9052
I took the metadata changes as is and they seem to work, though it now uses the module in another step. I'm not sure if this is the best and correct way.
Things to do:
* [x] ~~Make `run-pass/issue-28950.rs` pass~~ unrelated
* [x] Find out how the `PositionIndependentExecutable` setting is now used
* [x] Is the `llvm::legacy` still the right way to do these things?
cc @brson @alexcrichton
Add ARM MUSL targets
Rebase of #33189.
I tested this by producing a std for `arm-unknown-linux-musleabi` then I cross compiled Hello world to said target. Checked that the produced binary was statically linked and verified that the binary worked under QEMU.
This depends on rust-lang/libc#341. I'll have to update this PR after that libc PR is merged.
I'm also working on generating ARM musl cross toolchain via crosstool-ng. Once I verified those work, I'll send a PR to rust-buildbot.
r? @alexcrichton
cc @timonvo
The targets are:
- `arm-unknown-linux-musleabi`
- `arm-unknown-linux-musleabihf`
- `armv7-unknown-linux-musleabihf`
These mirror the existing `gnueabi` targets.
All of these targets produce fully static binaries, similar to the
x86 MUSL targets.
For now these targets can only be used with `--rustbuild` builds, as
https://github.com/rust-lang/compiler-rt/pull/22 only made the
necessary compiler-rt changes in the CMake configs, not the plain
GNU Make configs.
I've tested these targets GCC 5.3.0 compiled again musl-1.1.12
(downloaded from http://musl.codu.org/). An example `./configure`
invocation is:
```
./configure \
--enable-rustbuild
--target=arm-unknown-linux-musleabi \
--musl-root="$MUSL_ROOT"
```
where `MUSL_ROOT` points to the `arm-linux-musleabi` prefix.
Usually that path will be of the form
`/foobar/arm-linux-musleabi/arm-linux-musleabi`.
Usually the cross-compile toolchain will live under
`/foobar/arm-linux-musleabi/bin`. That path should either by added
to your `PATH` variable, or you should add a section to your
`config.toml` as follows:
```
[target.arm-unknown-linux-musleabi]
cc = "/foobar/arm-linux-musleabi/bin/arm-linux-musleabi-gcc"
cxx = "/foobar/arm-linux-musleabi/bin/arm-linux-musleabi-g++"
```
As a prerequisite you'll also have to put a cross-compiled static
`libunwind.a` library in `$MUSL_ROOT/lib`. This is similar to [how
the x86_64 MUSL targets are built]
(https://doc.rust-lang.org/book/advanced-linking.html).
Add MIR Optimization Tests
I've starting working on the infrastructure for testing MIR optimizations.
The plan now is to have a set of test cases (written in Rust), compile them with -Z dump-mir, and check the MIR before and after each pass.
The compiler-rt build system has been a never ending cause of pain for Rust
unfortunately:
* The build system is very difficult to invoke and configure to only build
compiler-rt, especially across platforms.
* The standard build system doesn't actually do what we want, not working for
some of our platforms and requiring a significant number of patches on our end
which are difficult to apply when updating compiler-rt.
* Compiling compiler-rt requires LLVM to be compiled, which... is a big
dependency! This also means that over time compiler-rt is not guaranteed to
build against older versions of LLVM (or newer versions), and we often want to
work with multiple versions of LLVM simultaneously.
The makefiles and rustbuild already know how to compile C code, the code here is
far from the *only* C code we're compiling. This patch jettisons all logic to
work with compiler-rt's build system and just goes straight to the source. We
just list all files manually (copied from compiler-rt's
lib/builtins/CMakeLists.txt) and compile them into an archive.
It's likely that this means we'll fail to pick up new files when we upgrade
compiler-rt, but that seems like a much less significant cost to pay than what
we're currently paying.
cc #34400, first steps towards that
llvm, rt: build using the Ninja generator if available
The Ninja generator generally builds much faster than make. It may also
be used on Windows to have a vast speed improvement over the Visual
Studio generators.
Currently hidden behind an `--enable-ninja` flag because it does not
obey the top-level `-j` or `-l` flags given to `make`.
If local-rust is the same as the current version, then force a local-rebuild
In Debian, we would like the option to build/rebuild the current release from
*either* the current or previous stable release. So we use enable-local-rust
instead of enable-local-rebuild, and read the bootstrap key dynamically from
whatever is installed locally.
In general, it does not make much sense to allow enable-local-rust without also
setting the bootstrap key, since the build would fail otherwise.
(The way I detect "the bootstrap key of [the local] rustc installation" is a bit hacky, suggestions welcome.)
Soon the LLVM upgrade (#34743) will require an updated CMake installation, and
the easiest way to do this was to upgrade the Ubuntu version of the bots to
16.04. This in turn brings in a new MIPS compiler on the linux-cross builder,
which is now from the "official" ubuntu repositories. Unfortunately these
new compilers don't support compiling with the `-msoft-float` flag like we're
currently passing, causing compiles to fail.
This commit removes these flags as it's not clear *why* they're being passed, as
the mipsel targets also don't have it. At least if it's not supported by a
debian default compiler, perhaps it's not too relevant to support?
The Ninja generator generally builds much faster than make. It may also
be used on Windows to have a vast speed improvement over the Visual
Studio generators.
Currently hidden behind an `--enable-ninja` flag because it does not
obey the top-level `-j` or `-l` flags given to `make`.
mk: Request -march=i686 on i686 Linux
Apparently the gcc on our dist bot is so old and/or obscure that the default
`-m32` switch doesn't think it can generate i686 code (or something like that).
The compiler-rt build system probes for the `__i686__` define in GCC to compile
for an i686 (vs i386) target, so this was failing on the bots.
This tweaks instead to pass `-march=i686` on i686-unknown-linux-gnu to C code to
ensure that we're compiling for i686 instead of i386. This should hopefully not
actually have an impact other than maybe doing some random optimization it
wasn't able to do so before. In theory this isn't making the target less
compatible as all Rust code is already compiled for i686.
Hopefully closes#34572
Apparently the gcc on our dist bot is so old and/or obscure that the default
`-m32` switch doesn't think it can generate i686 code (or something like that).
The compiler-rt build system probes for the `__i686__` define in GCC to compile
for an i686 (vs i386) target, so this was failing on the bots.
This tweaks instead to pass `-march=i686` on i686-unknown-linux-gnu to C code to
ensure that we're compiling for i686 instead of i386. This should hopefully not
actually have an impact other than maybe doing some random optimization it
wasn't able to do so before. In theory this isn't making the target less
compatible as all Rust code is already compiled for i686.
Hopefully closes#34572
Currently if an LLVM build is interrupted *after* it creates the llvm-config
binary but before it's done it puts us in an inconsistent state where we think
LLVM is compiled but it's not actually. This tweaks our logic to only consider
LLVM done building once it's actually done building.
This should hopefully alleviate problems on the bots where if we interrupt at
the wrong time it doesn't corrupt the build directory.
Try to fix the nightlies
They look to be failing right after the CMake PR landed. I've diagnosed and confirmed the first issue fixed, the second is a bit of a shot in the dark to see if it fixes things.
* Implement the clean-llvm target for those cases where makefiles are being used
* Have all cross-compiled LLVMs depend on the **host** LLVM as they'll require
the llvm-tablegen executable from there
This PR refactors the 'errors' part of libsyntax into its own crate (librustc_errors). This is the first part of a few refactorings to simplify error reporting and potentially support more output formats (like a standardized JSON output and possibly an --explain mode that can work with the user's code), though this PR stands on its own and doesn't assume further changes.
As part of separating out the errors crate, I have also refactored the code position portion of codemap into its own crate (libsyntax_pos). While it's helpful to have the common code positions in a separate crate for the new errors crate, this may also enable further simplifications in the future.
mk: Fix bootstrapping cross-hosts on beta
The beta builds are currently failing, unfortunately, due to what is presumably
some odd behavior with our makefiles. The wrong bootstrap key is being used to
generate the stage1 cross-compiled libraries, which fails the build.
Interestingly enough if the targets are directly specified as part of the build
then it works just fine! Just a bare `make` fails...
Instead of trying to understand what's happening in the makefiles instead just
tweak how we configure the bootstrap key in a way that's more likely to work.
The beta builds are currently failing, unfortunately, due to what is presumably
some odd behavior with our makefiles. The wrong bootstrap key is being used to
generate the stage1 cross-compiled libraries, which fails the build.
Interestingly enough if the targets are directly specified as part of the build
then it works just fine! Just a bare `make` fails...
Instead of trying to understand what's happening in the makefiles instead just
tweak how we configure the bootstrap key in a way that's more likely to work.
In Linux distributions, it is often necessary to rebuild packages for
cases like applying new patches or linking against new system libraries.
In this scenario, the rustc in the distro build environment may already
match the current release that we're trying to rebuild. Thus we don't
want to use the prior release's bootstrap key, nor `--cfg stage0` for
the prior unstable features.
The new `configure --enable-local-rebuild` option specifies that we are
rebuilding from the current release. The current bootstrap key is used
for the local rustc, and current stage1 features are also assumed.
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).
Add armv7-linux-androideabi target
This PR adds `armv7-linux-androideabi` target that matches `armeabi-v7a` Android ABI, ~~downscales `arm-linux-androideabi` target to match `armeabi` Android ABI~~ (TBD later if needed).
This should allow us to get the best performance from every [Android ABI level](http://developer.android.com/ndk/guides/abis.html).
Currently existing target `arm-linux-androideabi` started gaining features out of the supported range of [android `armeabi`](http://developer.android.com/ndk/guides/abis.html). While android compiler does not use a different target for later supported `armv7` architecture, it has distinct ABI name `armeabi-v7a`. We decided to add rust target `armv7-linux-androideabi` to match it.
Note that `NEON`, `VFPv3-D32`, and `ThumbEE` instruction sets are not added, because not all android devices are guaranteed to support all or some of these, and [their availability should be checked at runtime](http://developer.android.com/ndk/guides/abis.html#v7a).
~~This reduces performance of existing `arm-linux-androideabi` and may make it _much_ slower (we are talking more than order of magnitude in some random ad-hoc fp benchmark that I did).~~
Part of #33278.
make dist: specify the archive file as stdout
If the `-f` option isn't given, GNU tar will use environment variable
`TAPE` first, and next use the compiled-in default, which isn't
necessary `stdout` (it is the tape device `/dev/rst0` under OpenBSD for
example).
Implement constant support in MIR.
All of the intended features in `trans::consts` are now supported by `mir::constant`.
The implementation is considered a temporary measure until `miri` replaces it.
A `-Z orbit` bootstrap build will only translate LLVM IR from AST for `#[rustc_no_mir]` functions.
Furthermore, almost all checks of constant expressions have been moved to MIR.
In non-`const` functions, trees of temporaries are promoted, as per RFC 1414 (rvalue promotion).
Promotion before MIR borrowck would allow reasoning about promoted values' lifetimes.
The improved checking comes at the cost of four `[breaking-change]`s:
* repeat counts must contain a constant expression, e.g.:
`let arr = [0; { println!("foo"); 5 }];` used to be allowed (it behaved like `let arr = [0; 5];`)
* dereference of a reference to a `static` cannot be used in another `static`, e.g.:
`static X: [u8; 1] = [1]; static Y: u8 = (&X)[0];` was unintentionally allowed before
* the type of a `static` *must* be `Sync`, irrespective of the initializer, e.g.
`static FOO: *const T = &BAR;` worked as `&T` is `Sync`, but it shouldn't because `*const T` isn't
* a `static` cannot wrap `UnsafeCell` around a type that *may* need drop, e.g.
`static X: MakeSync<UnsafeCell<Option<String>>> = MakeSync(UnsafeCell::new(None));`
was previously allowed based on the fact `None` alone doesn't need drop, but in `UnsafeCell`
it can be later changed to `Some(String)` which *does* need dropping
The drop restrictions are relaxed by RFC 1440 (#33156), which is implemented, but feature-gated.
However, creating `UnsafeCell` from constants is unstable, so users can just enable the feature gate.
mk: Fix building with --enable-ccache
We will no longer use `ccache` in the makefiles for our local dependencies like
miniz, but they're so small anyway it doesn't really matter.
Closes#33285
