This pull request extracts all scheduling functionality from libstd, moving it into its own separate crates. The new libnative and libgreen will be the new way in which 1:1 and M:N scheduling is implemented. The standard library still requires an interface to the runtime, however, (think of things like `std::comm` and `io::println`). The interface is now defined by the `Runtime` trait inside of `std::rt`.
The booting process is now that libgreen defines the start lang-item and that's it. I want to extend this soon to have libnative also have a "start lang item" but also allow libgreen and libnative to be linked together in the same process. For now though, only libgreen can be used to start a program (unless you define the start lang item yourself). Again though, I want to change this soon, I just figured that this pull request is large enough as-is.
This certainly wasn't a smooth transition, certain functionality has no equivalent in this new separation, and some functionality is now better enabled through this new system. I did my best to separate all of the commits by topic and keep things fairly bite-sized, although are indeed larger than others.
As a note, this is currently rebased on top of my `std::comm` rewrite (or at least an old copy of it), but none of those commits need reviewing (that will all happen in another pull request).
For now, this moves the following modules to std::sync
* UnsafeArc (also removed unwrap method)
* mpsc_queue
* spsc_queue
* atomics
* mpmc_bounded_queue
* deque
We may want to remove some of the queues, but for now this moves things out of
std::rt into std::sync
This uses quite a bit of unsafe code for speed and failure safety, and allocates `2*n` temporary storage.
[Performance](https://gist.github.com/huonw/5547f2478380288a28c2):
| n | new | priority_queue | quick3 |
|-------:|---------:|---------------:|---------:|
| 5 | 200 | 155 | 106 |
| 100 | 6490 | 8750 | 5810 |
| 10000 | 1300000 | 1790000 | 1060000 |
| 100000 | 16700000 | 23600000 | 12700000 |
| sorted | 520000 | 1380000 | 53900000 |
| trend | 1310000 | 1690000 | 1100000 |
(The times are in nanoseconds, having subtracted the set-up time (i.e. the `just_generate` bench target).)
I imagine that there is still significant room for improvement, particularly because both priority_queue and quick3 are doing a static call via `Ord` or `TotalOrd` for the comparisons, while this is using a (boxed) closure.
Also, this code does not `clone`, unlike `quick_sort3`; and is stable, unlike both of the others.
Right now the --crate-id and related flags are all process *after* the entire
crate is parsed. This is less than desirable when used with makefiles because it
means that just to learn the output name of the crate you have to parse the
entire crate (unnecessary).
This commit changes the behavior to lift the handling of these flags much sooner
in the compilation process. This allows us to not have to parse the entire crate
and only have to worry about parsing the crate attributes themselves. The
related methods have all been updated to take an array of attributes rather than
a crate.
Additionally, this ceases duplication of the "what output are we producing"
logic in order to correctly handle things in the case of --test.
Finally, this adds tests for all of this functionality to ensure that it does
not regress.
For `str.as_mut_buf`, un-closure-ification is achieved by outright removal (see commit message). The others are replaced by `.as_ptr`, `.as_mut_ptr` and `.len`
As the title says. The trans changes will lead to an auxiliary alloca being created that allows debug info to track the `self` argument. This alloca is only created in debug builds however. Otherwise very little had to be done after I managed to navigate to some degree the jungle that is self-argument handling `:P`
Closes#10549
This code in resolve accidentally forced all types with an impl to become
public. This fixes it by default inheriting the privacy of what was previously
there and then becoming `true` if nothing else exits.
Closes#10545
When performing LTO, the rust compiler has an opportunity to completely strip
all landing pads in all dependent libraries. I've modified the LTO pass to
recognize the -Z no-landing-pads option when also running an LTO pass to flag
everything in LLVM as nothrow. I've verified that this prevents any and all
invoke instructions from being emitted.
I believe that this is one of our best options for moving forward with
accomodating use-cases where unwinding doesn't really make sense. This will
allow libraries to be built with landing pads by default but allow usage of them
in contexts where landing pads aren't necessary.
When performing LTO, the rust compiler has an opportunity to completely strip
all landing pads in all dependent libraries. I've modified the LTO pass to
recognize the -Z no-landing-pads option when also running an LTO pass to flag
everything in LLVM as nothrow. I've verified that this prevents any and all
invoke instructions from being emitted.
I believe that this is one of our best options for moving forward with
accomodating use-cases where unwinding doesn't really make sense. This will
allow libraries to be built with landing pads by default but allow usage of them
in contexts where landing pads aren't necessary.
cc #10780
This replaces the link meta attributes with a pkgid attribute and uses a hash
of this as the crate hash. This makes the crate hash computable by things
other than the Rust compiler. It also switches the hash function ot SHA1 since
that is much more likely to be available in shell, Python, etc than SipHash.
Fixes#10188, #8523.
This commit implements LTO for rust leveraging LLVM's passes. What this means
is:
* When compiling an rlib, in addition to insdering foo.o into the archive, also
insert foo.bc (the LLVM bytecode) of the optimized module.
* When the compiler detects the -Z lto option, it will attempt to perform LTO on
a staticlib or binary output. The compiler will emit an error if a dylib or
rlib output is being generated.
* The actual act of performing LTO is as follows:
1. Force all upstream libraries to have an rlib version available.
2. Load the bytecode of each upstream library from the rlib.
3. Link all this bytecode into the current LLVM module (just using llvm
apis)
4. Run an internalization pass which internalizes all symbols except those
found reachable for the local crate of compilation.
5. Run the LLVM LTO pass manager over this entire module
6a. If assembling an archive, then add all upstream rlibs into the output
archive. This ignores all of the object/bitcode/metadata files rust
generated and placed inside the rlibs.
6b. If linking a binary, create copies of all upstream rlibs, remove the
rust-generated object-file, and then link everything as usual.
As I have explained in #10741, this process is excruciatingly slow, so this is
*not* turned on by default, and it is also why I have decided to hide it behind
a -Z flag for now. The good news is that the binary sizes are about as small as
they can be as a result of LTO, so it's definitely working.
Closes#10741Closes#10740
Right now whenever an rlib file is linked against, all of the metadata from the
rlib is pulled in to the final staticlib or binary. The reason for this is that
the metadata is currently stored in a section of the object file. Note that this
is intentional for dynamic libraries in order to distribute metadata bundled
with static libraries.
This commit alters the situation for rlib libraries to instead store the
metadata in a separate file in the archive. In doing so, when the archive is
passed to the linker, none of the metadata will get pulled into the result
executable. Furthermore, the metadata file is skipped when assembling rlibs into
an archive.
The snag in this implementation comes with multiple output formats. When
generating a dylib, the metadata needs to be in the object file, but when
generating an rlib this needs to be separate. In order to accomplish this, the
metadata variable is inserted into an entirely separate LLVM Module which is
then codegen'd into a different location (foo.metadata.o). This is then linked
into dynamic libraries and silently ignored for rlib files.
While changing how metadata is inserted into archives, I have also stopped
compressing metadata when inserted into rlib files. We have wanted to stop
compressing metadata, but the sections it creates in object file sections are
apparently too large. Thankfully if it's just an arbitrary file it doesn't
matter how large it is.
I have seen massive reductions in executable sizes, as well as staticlib output
sizes (to confirm that this is all working).
The main one removed is rust_upcall_reset_stack_limit (continuation of #10156),
and this also removes the upcall_trace function. The was hidden behind a
`-Z trace` flag, but if you attempt to use this now you'll get a linker error
because there is no implementation of the 'upcall_trace' function. Due to this
no longer working, I decided to remove it entirely from the compiler (I'm also a
little unsure on what it did in the first place).
* Don't flag any address_insignificant statics as reachable because the whole
point of the address_insignificant optimization is that the static is not
reachable. Additionally, there's no need for it to be reachable because LLVM
optimizes it away.
* Be sure to not leak external node ids into our reachable set, this can
spuriously cause local items to be considered reachable if the node ids just
happen to line up
