Limit dylib symbols
This makes `windows-gnu` match the behavior of `windows-msvc`. It probably doesn't make sense to export these symbols on other platforms either.
Include frame pointer for bare metal RISC-V targets
This changes the default setting to enable the use of the frame pointer register when targeting RISC-V. On that architecture there is a dedicated frame pointer register which LLVM would otherwise never use so there is no increase in register pressure. Further, since these are bare metal targets, getting backtraces without the frame pointer is considerably more difficult (you can't just ask the OS to load the ELF executable and parse DWARF symbols). It is true that this setting can also be changed with the `-C force-frame-pointers` flag but that won't impact the compilation of the standard library, meaning that backtraces from, say, a panic handler would be useless.
Remove bitrig support from rust
Resolves#60743
using `find` and `rg` I delete every occurence of "bitrig" in the sources, expect for the llvm submodule (is this correct?).
There's also this file 5b8e99bb61/rls-analysis/test_data/rust-analysis/libstd-af9bacceee784405.json which contains a bitrig string in it. What to do with that?
Over in #60378, we made `rustc` switch LLVM target triples dynamically
based on the `MACOSX_DEPLOYMENT_TARGET` environment variable. This
change was made to align with `clang`'s behavior, and therefore make
cross-language LTO feasible on OS X. Otherwise, `rustc` would produce
LLVM bitcode files with a target triple of `x86_64-apple-darwin`,
`clang` would produce LLVM bitcode files with a target triple of
`x86_64-apple-macosx$VERSION`, and the linker would complain.
This change worked fine, except for one corner case: if you didn't have
`MACOSX_DEPLOYMENT_TARGET` set, and you wanted to do LTO on just Rust
code, you'd get warning messages similar to:
```
warning: Linking two modules of different target triples: ' is 'x86_64-apple-macosx10.7.0' whereas 'main.7rcbfp3g-cgu.4' is 'x86_64-apple-darwin'
```
This message occurs because libstd is compiled with
`MACOSX_DEPLOYMENT_TARGET` set to 10.7. The LLVM bitcode distributed in
libstd's rlibs, then, is tagged with the target triple of
`x86_64-apple-macosx10.7.0`, while the bitcode `rustc` produces for
"user" code is tagged with the target triple of `x86_64-apple-darwin`.
It's not good to have LTO on just Rust code (probably much more common
than cross-language LTO) warn by default. These warnings also break
Cargo's testsuite.
This change defaults to acting as though `MACOSX_DEPLOYMENT_TARGET` was
set to 10.7. "user" code will then be given a target triple that is
equivalent to the target triple libstd bitcode is already using. The
above warning will therefore go away.
`rustc` already assumes that compiling without
`MACOSX_DEPLOYMENT_TARGET` means that we're compiling for a target
compatible with OS X 10.7 (e.g. that things like TLS work properly). So
this change is really just making things conform more closely to the
status quo.
(It's also worth noting that before and after this patch, compiling with
`MACOSX_DEPLOYMENT_TARGET` set to, say, 10.9, works just fine: target
triples with an "apple" version ignore OS versions when checking
compatibility, so bitcode with a `x86_64-apple-macosx10.7.0` triple works just
fine with bitcode with a `x86_64-apple-macosx10.9.0` triple.)
This renames wasm32-unknown-wasi to wasm32-wasi, omitting the vendor
component. This follows aarch64-linux-android, x86_64-fuchsia, and others in
omitting the vendor field, which has the advantage of aligning with the
[multiarch tuple](https://wiki.debian.org/Multiarch/Tuples), and of being
less noisy.
conditionally modify darwin targets to macosx targets with versions
We need this behavior so that Rust LLVM IR objects match the target triple for Clang LLVM IR objects. This matching then convinces the linker that yes, you really can do cross-language LTO with objects from different compilers.
The newly-added tests seem to pass locally on x86_64-unknown-linux-gnu. I haven't done a full test run or tried the new compiler in an cross-language LTO setup yet.
Move pointee_info_at from rustc_codegen_llvm to rustc_target.
Makes progress towards #56166.
This is a continuation of https://github.com/rust-lang/rust/pull/57150.
@oli-obk Should I close the older PR?
This distinction is fairly abstract, but in practice, the main advantage
here is that LLVM's triple code considers WASI to be an OS, so this
makes rustc agree with that.
LLVM 9 is adding support for a "pic" relocation model for wasm code,
which is quite different than the current model. In order to preserve
the mode of compilation that we have today default to "static" to ensure
that we don't accidentally start creating experimental relocatable
binaries.
rustc_target: factor out common fields of non-Single Variants.
@tmandry and I were discussing ways to generalize the current variants/discriminant layout to allow more fields in the "`enum`" (or another multi-variant types, such as potentially generator state, in the future), shared by all variants, than just the tag/niche discriminant.
This refactor should make it easier to extend multi-variant layouts, as nothing is duplicating anymore between "tagged enums" and "niche-filling enums".
r? @oli-obk
This commit adds a new wasm32-based target distributed through rustup,
supported in the standard library, and implemented in the compiler. The
`wasm32-unknown-wasi` target is intended to be a WebAssembly target
which matches the [WASI proposal recently announced.][LINK]. In summary
the WASI target is an effort to define a standard set of syscalls for
WebAssembly modules, allowing WebAssembly modules to not only be
portable across architectures but also be portable across environments
implementing this standard set of system calls.
The wasi target in libstd is still somewhat bare bones. This PR does not
fill out the filesystem, networking, threads, etc. Instead it only
provides the most basic of integration with the wasi syscalls, enabling
features like:
* `Instant::now` and `SystemTime::now` work
* `env::args` is hooked up
* `env::vars` will look up environment variables
* `println!` will print to standard out
* `process::{exit, abort}` should be hooked up appropriately
None of these APIs can work natively on the `wasm32-unknown-unknown`
target, but with the assumption of the WASI set of syscalls we're able
to provide implementations of these syscalls that engines can implement.
Currently the primary engine implementing wasi is [wasmtime], but more
will surely emerge!
In terms of future development of libstd, I think this is something
we'll probably want to discuss. The purpose of the WASI target is to
provide a standardized set of syscalls, but it's *also* to provide a
standard C sysroot for compiling C/C++ programs. This means it's
intended that functions like `read` and `write` are implemented for this
target with a relatively standard definition and implementation. It's
unclear, therefore, how we want to expose file descriptors and how we'll
want to implement system primitives. For example should `std::fs::File`
have a libc-based file descriptor underneath it? The raw wasi file
descriptor? We'll see! Currently these details are all intentionally
hidden and things we can change over time.
A `WasiFd` sample struct was added to the standard library as part of
this commit, but it's not currently used. It shows how all the wasi
syscalls could be ergonomically bound in Rust, and they offer a possible
implementation of primitives like `std::fs::File` if we bind wasi file
descriptors exactly.
Apart from the standard library, there's also the matter of how this
target is integrated with respect to its C standard library. The
reference sysroot, for example, provides managment of standard unix file
descriptors and also standard APIs like `open` (as opposed to the
relative `openat` inspiration for the wasi ssycalls). Currently the
standard library relies on the C sysroot symbols for operations such as
environment management, process exit, and `read`/`write` of stdio fds.
We want these operations in Rust to be interoperable with C if they're
used in the same process. Put another way, if Rust and C are linked into
the same WebAssembly binary they should work together, but that requires
that the same C standard library is used.
We also, however, want the `wasm32-unknown-wasi` target to be
usable-by-default with the Rust compiler without requiring a separate
toolchain to get downloaded and configured. With that in mind, there's
two modes of operation for the `wasm32-unknown-wasi` target:
1. By default the C standard library is statically provided inside of
`liblibc.rlib` distributed as part of the sysroot. This means that
you can `rustc foo.wasm --target wasm32-unknown-unknown` and you're
good to go, a fully workable wasi binary pops out. This is
incompatible with linking in C code, however, which may be compiled
against a different sysroot than the Rust code was previously
compiled against. In this mode the default of `rust-lld` is used to
link binaries.
2. For linking with C code, the `-C target-feature=-crt-static` flag
needs to be passed. This takes inspiration from the musl target for
this flag, but the idea is that you're no longer using the provided
static C runtime, but rather one will be provided externally. This
flag is intended to also get coupled with an external `clang`
compiler configured with its own sysroot. Therefore you'll typically
use this flag with `-C linker=/path/to/clang-script-wrapper`. Using
this mode the Rust code will continue to reference standard C
symbols, but the definition will be pulled in by the linker configured.
Alright so that's all the current state of this PR. I suspect we'll
definitely want to discuss this before landing of course! This PR is
coupled with libc changes as well which I'll be posting shortly.
[LINK]:
[wasmtime]:
This commit adds support code for using `clang` directly to link the
wasm32-unknown-unknown target. Currently the target is only really
configured to link with LLD directly, but this ensures that `clang` can
be configured as well.
While not immediately useful in the near term it's likely that more
wasm32 targets will pop up over time with Clang's new native support for
WebAssembly in the 8.0.0 release. Getting support into rustc early
should make it easier to experiment with these targets and try out
various changes here and there.
Default to integrated `rust-lld` linker for UEFI targets
The `x86_64-unknown-uefi` target was added in https://github.com/rust-lang/rust/pull/56769 with the linker defaulting to `lld-link`. This means that a system linker with that name is required for linking.
I think defaulting to `rust-lld`, which is shipped with Rust, is a better default for the following reasons:
- Most systems don't have `lld-link` installed, so it forces users to install it first.
- The naming of LLD executables is not standarized, so users often need to create an additional symlink before things work. For example, on Ubuntu `apt install lld` leads to an executable named `lld-link-6.0`.
- We already default to `rust-lld` for [many targets](https://github.com/rust-lang/rust/search?utf8=%E2%9C%93&q=rust-lld&type=), including embedded and WASM targets, so doing the same for UEFI crates seems consistent to me. (It even seems like `x86_64-unknown-uefi` is the [only target](https://github.com/rust-lang/rust/search?q=lld-link&unscoped_q=lld-link) that uses `lld-link`.)
cc @dvdhrm who added the target and @kkk669 who [proposed to use `rust-lld`](https://github.com/rust-lang/rust/pull/56769#issuecomment-461119648).
MIPS: add r6 support
MIPS r6 is quite different with the previous version.
It use some new target triples:
mipsisa32r6-unknown-linux-gnu
mipsisa32r6el-unknown-linux-gnu
mipsisa64r6-unknown-linux-gnuabi64
mipsisa64r6el-unknown-linux-gnuabi64
This patch has been tested with Debian Port for mips64r6el,
and the support of these triples also is included in llvm:
https://reviews.llvm.org/rGe58c45a695f39004710b6ce940d489fee800dbd3
MIPS r6 is quite different with the previous version.
It use some new target triples:
mipsisa32r6-unknown-linux-gnu
mipsisa32r6el-unknown-linux-gnu
mipsisa64r6-unknown-linux-gnuabi64
mipsisa64r6el-unknown-linux-gnuabi64
This patch has been tested with Debian Port for mips64r6el,
and the support of these triples also is included in llvm:
https://reviews.llvm.org/rGe58c45a695f39004710b6ce940d489fee800dbd3
Function signatures with the `variadic` member set are actually
C-variadic functions. Make this a little more explicit by renaming the
`variadic` boolean value, `c_variadic`.
Before this commit, if the builtin target was found, but an error
happened when instantiating it (e.g. validating the target
specification file failed, etc.), then we ignored those errors
and proceeded to try to find a `target_triple.json` file, and if
that failed, reported that as an error.
With this commit, if rustc is supposed to provide the builtin target,
and something fails while instantiating it, that error will
get properly propagated.
This clarifies why FP-units are disabled on UEFI targets, as well as
why we must opt into the NXCOMPAT feature.
I did find some time to investigate why GRUB and friends disable FP on
UEFI. The specification explicitly allows using MMX/SSE/AVX, but as it
turns out it does not mandate enabling the instruction sets explicitly.
Hence, any use of these instructions will trigger CPU exceptions,
unless an application explicitly enables them (which is not an option,
as these are global flags that better be controlled by the
kernel/firmware).
Furthermore, UEFI systems are allowed to mark any non-code page as
non-executable. Hence, we must make sure to never place code on the
stack or heap. So we better pass /NXCOMPAT to the linker for it to
complain if it ever places code in non-code pages.
Lastly, this fixes some typos in related comments.
