Just like DragonFlyBSD, using the same symbols as the system allocator will
result in a segmentation fault at runtime due to allocator mismatches.
As such, prefix the jemalloc symbols instead.
This hides symbols from various unstable and implementation-detail
crates of the standard library. Although typically transitive exported
`pub extern` functions are exported from cdylibs, these crates aren't
necessary as they're all implementation details.
Closes#34493
Redox Cross Compilation
I will admit - there are things here that I wish I did not have to do. This completes the ability to create a cross compiler from the rust repository for `x86_64-unknown-redox`. I will document this PR with inline comments explaining some things.
[View this gist to see how a cross compiler is built](https://gist.github.com/jackpot51/6680ad973986e84d69c79854249f2b7e)
Prior discussion of a smaller change is here: https://github.com/rust-lang/rust/pull/38366
This commit switches the default build system for Rust from the makefiles to
rustbuild. The rustbuild build system has been in development for almost a year
now and has become quite mature over time. This commit is an implementation of
the proposal on [internals] which slates deletion of the makefiles on
2016-01-02.
[internals]: https://internals.rust-lang.org/t/proposal-for-promoting-rustbuild-to-official-status/4368
This commit also updates various documentation in `README.md`,
`CONTRIBUTING.md`, `src/bootstrap/README.md`, and throughout the source code of
rustbuild itself.
Closes#37858
the .git directory is modified by `bootstrap` when it updates this git
submodule; this triggered rebuilds every time `bootstrap` was called.
likely fixes#38094
This is a hack to support building targets that don't support jemalloc
alongside hosts that do. The jemalloc build is controlled by a feature
of the std crate, and if that feature changes between targets, it
invalidates the fingerprint of std's build script (this is a cargo
bug); so we must ensure that the feature set used by std is the same
across all targets, which means we have to build the alloc_jemalloc
crate for targets like emscripten, even if we don't use it.
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).
Now that we properly only link in jemalloc when building executables, we have
far less to worry about in terms of polluting the global namespace with the
`free` and `malloc` symbols on Linux. This commit will primarily allow LLVM to
use jemalloc so the compiler will only be using one allocator overall.
Locally this took compile time for libsyntax from 95 seconds to 89 (a 6%
improvement).
Have all Cargo-built crates pass `--cfg cargobuild` and then add appropriate
`#[cfg]` definitions to all crates to avoid linking anything if this is passed.
This should help allow libstd to compile with both the makefiles and with Cargo.
This commits adds build scripts to the necessary Rust crates for all the native
dependencies. This is currently a duplication of the support found in mk/rt.mk
and is my best effort at representing the logic twice, but there may be some
unfortunate-and-inevitable divergence.
As a summary:
* alloc_jemalloc - build script to compile jemallocal
* flate - build script to compile miniz.c
* rustc_llvm - build script to run llvm-config and learn about how to link it.
Note that this crucially (and will not ever) compile LLVM as that would take
far too long.
* rustdoc - build script to compile hoedown
* std - script to determine lots of libraries/linkages as well as compile
libbacktrace
