These aren't really used for anything any more, so there doesn't seem to be much
reason to leave them around in the `rt` directory. There was some limiting of
threads spawned or tests when run under valgrind, but very little is run under
valgrind nowadays so there's also no real use keeping these around.
These aren't really used for anything any more, so there doesn't seem to be much
reason to leave them around in the `rt` directory. There was some limiting of
threads spawned or tests when run under valgrind, but very little is run under
valgrind nowadays so there's also no real use keeping these around.
Makes the lint a bit more accurate, and improves the quality of the diagnostic
messages by explicitly returning an error message.
The new lint is also a little more aggressive: specifically, it now
rejects tuples, and it recurses into function pointers.
This commit moves the IR files in the distribution, rust_try.ll,
rust_try_msvc_64.ll, and rust_try_msvc_32.ll into the compiler from the main
distribution. There's a few reasons for this change:
* LLVM changes its IR syntax from time to time, so it's very difficult to
have these files build across many LLVM versions simultaneously. We'll likely
want to retain this ability for quite some time into the future.
* The implementation of these files is closely tied to the compiler and runtime
itself, so it makes sense to fold it into a location which can do more
platform-specific checks for various implementation details (such as MSVC 32
vs 64-bit).
* This removes LLVM as a build-time dependency of the standard library. This may
end up becoming very useful if we move towards building the standard library
with Cargo.
In the immediate future, however, this commit should restore compatibility with
LLVM 3.5 and 3.6.
This commit moves the IR files in the distribution, rust_try.ll,
rust_try_msvc_64.ll, and rust_try_msvc_32.ll into the compiler from the main
distribution. There's a few reasons for this change:
* LLVM changes its IR syntax from time to time, so it's very difficult to
have these files build across many LLVM versions simultaneously. We'll likely
want to retain this ability for quite some time into the future.
* The implementation of these files is closely tied to the compiler and runtime
itself, so it makes sense to fold it into a location which can do more
platform-specific checks for various implementation details (such as MSVC 32
vs 64-bit).
* This removes LLVM as a build-time dependency of the standard library. This may
end up becoming very useful if we move towards building the standard library
with Cargo.
In the immediate future, however, this commit should restore compatibility with
LLVM 3.5 and 3.6.
This can fail on linux for various reasons, such as the /proc filesystem not
being mounted. There are already many cases where we can't set up stack guards,
so just don't worry about this case and communicate that no guard was enabled.
I've confirmed that this allows the compiler to run in a chroot without /proc
mounted.
Closes#22642
This PR was originally going to be a "let's start running tests on MSVC" PR, but it didn't quite get to that point. It instead gets us ~80% of the way there! The steps taken in this PR are:
* Landing pads are turned on by default for 64-bit MSVC. The LLVM support is "good enough" with the caveat the destructor glue is now marked noinline. This was recommended [on the associated bug](https://llvm.org/bugs/show_bug.cgi?id=23884) as a stopgap until LLVM has a better representation for exception handling in MSVC. The consequence of this is that MSVC will have a bit of a perf hit, but there are possible routes we can take if this workaround sticks around for too long.
* The linker (`link.exe`) is now looked up in the Windows Registry if it's not otherwise available in the environment. This improves using the compiler outside of a VS shell (e.g. in a MSYS shell or in a vanilla cmd.exe shell). This also makes cross compiles via Cargo "just work" when crossing between 32 and 64 bit!
* TLS destructors were fixed to start running on MSVC (they previously weren't running at all)
* A few assorted `run-pass` tests were fixed.
* The dependency on the `rust_builtin` library was removed entirely for MSVC to try to prevent any `cl.exe` compiled objects get into the standard library. This should help us later remove any dependence on the CRT by the standard library.
* I re-added `rust_try_msvc_32.ll` for 32-bit MSVC and ensured that landing pads were turned off by default there as well.
Despite landing pads being enabled, there are still *many* failing tests on MSVC. The two major classes I've identified so far are:
* Spurious aborts. It appears that when optimizations are enabled that landing pads aren't always lined up properly, and sometimes an exception being thrown can't find the catch block down the stack, causing the program to abort. I've been working to reduce this test case but haven't been met with great success just yet.
* Parallel codegen does not work on MSVC. Our current strategy is to take the N object files emitted by the N codegen threads and use `ld -r` to assemble them into *one* object file. The MSVC linker, however, does not have this ability, and this will need to be rearchitected to work on MSVC.
I will fix parallel codegen in a future PR, and I'll also be watching LLVM closely to see if the aborts... disappear!
This library has no shims which are actually needed on Windows now, so translate
that last easy one into Rust and then don't link it at all on Windows.
Now that LLVM has been updated, the only remaining roadblock to implementing
unwinding for MSVC is to fill out the runtime support in `std::rt::unwind::seh`.
This commit does precisely that, fixing up some other bits and pieces along the
way:
* The `seh` unwinding module now uses `RaiseException` to initiate a panic.
* The `rust_try.ll` file was rewritten for MSVC (as it's quite different) and is
located at `rust_try_msvc_64.ll`, only included on MSVC builds for now.
* The personality function for all landing pads generated by LLVM is hard-wired
to `__C_specific_handler` instead of the standard `rust_eh_personality` lang
item. This is required to get LLVM to emit SEH unwinding information instead
of DWARF unwinding information. This also means that on MSVC the
`rust_eh_personality` function is entirely unused (but is defined as it's a
lang item).
More details about how panicking works on SEH can be found in the
`rust_try_msvc_64.ll` or `seh.rs` files, but I'm always open to adding more
comments!
A key aspect of this PR is missing, however, which is that **unwinding is still
turned off by default for MSVC**. There is a [bug in llvm][llvm-bug] which
causes optimizations to inline enough landing pads that LLVM chokes. If the
compiler is optimized at `-O1` (where inlining isn't enabled) then it can
bootstrap with unwinding enabled, but when optimized at `-O2` (inlining is
enabled) then it hits a fatal LLVM error.
[llvm-bug]: https://llvm.org/bugs/show_bug.cgi?id=23884
Closes#25977
The various `stdfoo_raw` methods in std::io now return `io::Result`s,
since they may not exist on Windows. They will always return `Ok` on
Unix-like platforms.
[breaking-change]
This commit adds a small non-generic non-inlineable shim function to
`rt::unwind::try` which the compiler can take care of for managing the exported
symbol instead of having to edit `src/rt/rust_try.ll`
At this time unwinding support is not implemented for MSVC as
`libgcc_s_seh-1.dll` is not available by default (and this is used on MinGW),
but this should be investigated soon. For now this change is just aimed at
getting the compiler far enough to bootstrap everything instead of successfully
running tests.
This commit refactors the `std::rt::unwind` module a bit to prepare for SEH
support eventually by moving all GCC-specific functionality to its own submodule
and defining the interface needed.
An automated script was run against the `.rs` and `.md` files,
subsituting every occurrence of `task` with `thread`. In the `.rs`
files, only the texts in the comment blocks were affected.
This commit modifies the standard library and its dependencies to link correctly
when built against MUSL. This primarily ensures that the right libraries are
linked against and when they're linked against they're linked against
statically.
Changes the style guidelines regarding unit tests to recommend using a
sub-module named "tests" instead of "test" for unit tests as "test"
might clash with imports of libtest.
It's just as convenient, but it's much faster. Using write! requires an
extra call to fmt::write and a extra dynamically dispatched call to
Arguments' Display format function.
Now that we have a `#[allow_internal_unstable]` attribute for macros there's no
need for these two `begin_unwind` functions to be stable. Right now the `panic!`
interface is the only one we wish to stabilize, so remove the stability markers
from these functions.
While this is a breaking change, it is highly unlikely to break any actual code.
It is recommended to use the `panic!` macro instead if it breaks explicit calls
into `std::rt`.
[breaking-change]
cc #24208
for `Box<FnBox()>`. I found the alias was still handy because it is
shorter than the fully written type.
This is a [breaking-change]: convert code using `Invoke` to use `FnBox`,
which is usually pretty straight-forward. Code using thunk mostly works
if you change `Thunk::new => Box::new` and `foo.invoke(arg)` to
`foo(arg)`.
This commit cleans out a large amount of deprecated APIs from the standard
library and some of the facade crates as well, updating all users in the
compiler and in tests as it goes along.
This permits all coercions to be performed in casts, but adds lints to warn in those cases.
Part of this patch moves cast checking to a later stage of type checking. We acquire obligations to check casts as part of type checking where we previously checked them. Once we have type checked a function or module, then we check any cast obligations which have been acquired. That means we have more type information available to check casts (this was crucial to making coercions work properly in place of some casts), but it means that casts cannot feed input into type inference.
[breaking change]
* Adds two new lints for trivial casts and trivial numeric casts, these are warn by default, but can cause errors if you build with warnings as errors. Previously, trivial numeric casts and casts to trait objects were allowed.
* The unused casts lint has gone.
* Interactions between casting and type inference have changed in subtle ways. Two ways this might manifest are:
- You may need to 'direct' casts more with extra type information, for example, in some cases where `foo as _ as T` succeeded, you may now need to specify the type for `_`
- Casts do not influence inference of integer types. E.g., the following used to type check:
```
let x = 42;
let y = &x as *const u32;
```
Because the cast would inform inference that `x` must have type `u32`. This no longer applies and the compiler will fallback to `i32` for `x` and thus there will be a type error in the cast. The solution is to add more type information:
```
let x: u32 = 42;
let y = &x as *const u32;
```
There have been some recent panics on the bots and this commit is an attempt to
appease them. Previously it was considered invalid to run `rt::at_exit` after
the handlers had already started running. Due to the multithreaded nature of
applications, however, it is not always possible to guarantee this. For example
[this program][ex] will show off the abort.
[ex]: https://gist.github.com/alexcrichton/56300b87af6fa554e52d
The semantics of the `rt::at_exit` function have been modified as such:
* It is now legal to call `rt::at_exit` at any time. The return value now
indicates whether the closure was successfully registered or not. Callers must
now decide what to do with this information.
* The `rt::at_exit` handlers will now be run for a fixed number of iterations.
Common cases (such as the example shown) may end up registering a new handler
while others are running perhaps once or twice, so this common condition is
covered by re-running the handlers a fixed number of times, after which new
registrations are forbidden.
Some usage of `rt::at_exit` was updated to handle these new semantics, but
deprecated or unstable libraries calling `rt::at_exit` were not updated.
This commit removes the reexports of `old_io` traits as well as `old_path` types
and traits from the prelude. This functionality is now all deprecated and needs
to be removed to make way for other functionality like `Seek` in the `std::io`
module (currently reexported as `NewSeek` in the io prelude).
Closes#23377Closes#23378
This reverts commit aec67c2.
Closes#20012
This is temporarily rebased on #23245 as it would otherwise conflict, the last commit is the only one relevant to this PR though.
As @alexcrichton says, this was really a libgreen thing, and isn't
relevant now.
As this removes a technically-public function, this is a
[breaking-change]
Conflicts:
src/libtest/lib.rs
Many of the modifications putting in `Box::new` calls also include a
pointer to Issue 22405, which tracks going back to `box <expr>` if
possible in the future.
(Still tried to use `Box<_>` where it sufficed; thus some tests still
have `box_syntax` enabled, as they use a mix of `box` and `Box::new`.)
Precursor for overloaded-`box` and placement-`in`; see Issue 22181.
