This commit works around the newly-introduced LLVM shared library.
This is needed such that llvm-config run from
librustc_llvm's build script can correctly locate it's own LLVM, not the
one in stage0/lib. The LLVM build system uses the DT_RUNPATH/RUNPATH
header within the llvm-config binary, which we want to use, but because
Cargo always adds the host compiler's "libdir" (stage0/lib in our
case) to the dynamic linker's search path, we weren't properly finding
the freshly-built LLVM in llvm/lib. By restoring the environment
variable setting the search path to what bootstrap sees, the problem is
resolved and librustc_llvm correctly links and finds the appropriate
LLVM.
Several run-make-fulldeps tests are also updated with similar handling.
Ever since we added a Cargo-based build system for the compiler the
standard library has always been a little special, it's never been able
to depend on crates.io crates for runtime dependencies. This has been a
result of various limitations, namely that Cargo doesn't understand that
crates from crates.io depend on libcore, so Cargo tries to build crates
before libcore is finished.
I had an idea this afternoon, however, which lifts the strategy
from #52919 to directly depend on crates.io crates from the standard
library. After all is said and done this removes a whopping three
submodules that we need to manage!
The basic idea here is that for any crate `std` depends on it adds an
*optional* dependency on an empty crate on crates.io, in this case named
`rustc-std-workspace-core`. This crate is overridden via `[patch]` in
this repository to point to a local crate we write, and *that* has a
`path` dependency on libcore.
Note that all `no_std` crates also depend on `compiler_builtins`, but if
we're not using submodules we can publish `compiler_builtins` to
crates.io and all crates can depend on it anyway! The basic strategy
then looks like:
* The standard library (or some transitive dep) decides to depend on a
crate `foo`.
* The standard library adds
```toml
[dependencies]
foo = { version = "0.1", features = ['rustc-dep-of-std'] }
```
* The crate `foo` has an optional dependency on `rustc-std-workspace-core`
* The crate `foo` has an optional dependency on `compiler_builtins`
* The crate `foo` has a feature `rustc-dep-of-std` which activates these
crates and any other necessary infrastructure in the crate.
A sample commit for `dlmalloc` [turns out to be quite simple][commit].
After that all `no_std` crates should largely build "as is" and still be
publishable on crates.io! Notably they should be able to continue to use
stable Rust if necessary, since the `rename-dependency` feature of Cargo
is soon stabilizing.
As a proof of concept, this commit removes the `dlmalloc`,
`libcompiler_builtins`, and `libc` submodules from this repository. Long
thorns in our side these are now gone for good and we can directly
depend on crates.io! It's hoped that in the long term we can bring in
other crates as necessary, but for now this is largely intended to
simply make it easier to manage these crates and remove submodules.
This should be a transparent non-breaking change for all users, but one
possible stickler is that this almost for sure breaks out-of-tree
`std`-building tools like `xargo` and `cargo-xbuild`. I think it should
be relatively easy to get them working, however, as all that's needed is
an entry in the `[patch]` section used to build the standard library.
Hopefully we can work with these tools to solve this problem!
[commit]: 28ee12db81
This commit deletes the `alloc_system` crate from the standard
distribution. This unstable crate is no longer needed in the modern
stable global allocator world, but rather its functionality is folded
directly into the standard library. The standard library was already the
only stable location to access this crate, and as a result this should
not affect any stable code.
This commit is an attempted fix at #50887. It was noticed that on that issue
we're building both x86_64 and i386 versions of libraries, but we only actually
need the x86_64 versions! This hopes that the build race condition exhibited
in #50887 is connected to building both architectures and/or building a lot of
libraries, so this should help us build precisely what we need and no more.
This PR is an implementation of [RFC 1974] which specifies a new method of
defining a global allocator for a program. This obsoletes the old
`#![allocator]` attribute and also removes support for it.
[RFC 1974]: https://github.com/rust-lang/rfcs/pull/197
The new `#[global_allocator]` attribute solves many issues encountered with the
`#![allocator]` attribute such as composition and restrictions on the crate
graph itself. The compiler now has much more control over the ABI of the
allocator and how it's implemented, allowing much more freedom in terms of how
this feature is implemented.
cc #27389
ASan and TSan are supported on macOS, and this commit enables their
support.
The sanitizers are always built as *.dylib on Apple platforms, so they
cannot be statically linked into the corresponding `rustc_?san.rlib`. The
dylibs are directly copied to `lib/rustlib/x86_64-apple-darwin/lib/`
instead.
Note, although Xcode also ships with their own copies of ASan/TSan dylibs,
we cannot use them due to version mismatch.
There is a caveat: the sanitizer libraries are linked as @rpath, so the
user needs to additionally pass `-C rpath`:
rustc -Z sanitizer=address -C rpath file.rs
^~~~~~~~
Otherwise there will be a runtime error:
dyld: Library not loaded: @rpath/libclang_rt.asan_osx_dynamic.dylib
Referenced from: /path/to/executable
Reason: image not found
Abort trap: 6
The next commit includes a temporary change in compiler to force the linker
to emit a usable @rpath.
Now that we've also updated cargo's release process this commit also changes the
download location of Cargo from Cargos archives back to the static.r-l.o
archives. This should ensure that the Cargo download is the exact Cargo paired
with the rustc that we release.
