This commit changes drop glue generated for structs to use the invoke LLVM
instruction instead of call. What this means is that if the user destructor
triggers an unwinding, then the fields of the struct will still ge dropped.
This is not an attempt to support failing while failing, as that's mostly a
problem of runtime support. This is more of an issue of soundness in making sure
that destructors are appropriately run. The test included fails before this
commit, and only has one call to fail!(), yet it doesn't destroy its struct
fields.
New standards have arisen in recent months, mostly for the use of
rustpkg, but the main Rust codebase has not been altered to match these
new specifications. This changeset rectifies most of these issues.
- Renamed the crate source files `src/libX/X.rs` to `lib.rs`, for
consistency with current styles; this affects extra, rustc, rustdoc,
rustpkg, rustuv, std, syntax.
- Renamed `X/X.rs` to `X/mod.rs,` as is now recommended style, for
`std::num` and `std::terminfo`.
- Shifted `src/libstd/str/ascii.rs` out of the otherwise unused `str`
directory, to be consistent with its import path of `std::ascii`;
libstd is flat at present so it's more appropriate thus.
While this removes some `#[path = "..."]` directives, it does not remove
all of them, and leaves certain other inconsistencies, such as `std::u8`
et al. which are actually stored in `src/libstd/num/` (one subdirectory
down). No quorum has been reached on this issue, so I felt it best to
leave them all alone at present. #9208 deals with the possibility of
making libstd more hierarchical (such as changing the crate to match the
current filesystem structure, which would make the module path
`std::num::u8`).
There is one thing remaining in which this repository is not
rustpkg-compliant: rustpkg would have `src/std/` et al. rather than
`src/libstd/` et al. I have not endeavoured to change that at this point
as it would guarantee prompt bitrot and confusion. A change of that
magnitude needs to be discussed first.
This commit removes the propagation of `link_args` attributes across crates. The first commit message has the reasons as to why. Additionally, this starts statically linking some C/C++ helper libraries that we have to their respective crates instead of throwing then in librustrt and then having everything depend on librustrt.
The major downside of this movement is that we're losing the ability to control visible symbols. I couldn't figure out a way to internalize symbols from a static library during the linking process, so everyone who links to librustdoc will be able to use its sundown implementation (not exactly ideal). I'm not entirely sure how to fix this (beyond generating a list of all public symbols, including rust ones, and passing that to the linker), but we may have a much easier time with this once we start using llvm's linker toolchain.
There's certainly a lot more possibilities in where this can go, but I didn't want to go too deep just yet. The main idea here is to stop propagating linker arguments and then see how we're able to start statically linking libraries as a result.
r? @catamorphism, you're going to be working on linking soon, so feel free to completely throw this away for something else!
Similarly to the previous commit, libuv is only used by this library, so there's
no need for it to be linked into librustrt and available to all crates by
default.
Previously, all functions called by a reachable function were considered
reachable, but this is only the case if the original function was possibly
inlineable (if it's type generic or #[inline]-flagged).
This is a fairly brittle modle that doesn't scale well across many crates. It's
unlikely that all of the downstream crates will have all of the original native
dependencies of all the upstream crates. In the case that FFI functions are
reachable, then it should be the responsibility of the downstream crate to link
against the correct library, or the upstream crate should prevent the functions
from being reachable.
Cleaned up the source in a few places
Renamed `map_move` to `map`, removed other `map` methods
Added `as_ref` and `as_mut` adapters to `Result`
Added `fmt::Default` impl
This commit changes drop glue generated for structs to use the invoke LLVM
instruction instead of call. What this means is that if the user destructor
triggers an unwinding, then the fields of the struct will still ge dropped.
This is not an attempt to support failing while failing, as that's mostly a
problem of runtime support. This is more of an issue of soundness in making sure
that destructors are appropriately run. The test included fails before this
commit, and only has one call to fail!(), yet it doesn't destroy its struct
fields.
Previously, all functions called by a reachable function were considered
reachable, but this is only the case if the original function was possibly
inlineable (if it's type generic or #[inline]-flagged).
Allows an enum with a discriminant to use any of the primitive integer types to store it. By default the smallest usable type is chosen, but this can be overridden with an attribute: `#[repr(int)]` etc., or `#[repr(C)]` to match the target's C ABI for the equivalent C enum.
Also adds a lint pass for using non-FFI safe enums in extern declarations, checks that specified discriminants can be stored in the specified type if any, and fixes assorted code that was assuming int.
This is one of the final steps needed to complete #9128. It still needs a little bit of polish before closing that issue, but it's in a pretty much "done" state now.
The idea here is that the entire event loop implementation using libuv is now housed in `librustuv` as a completely separate library. This library is then injected (via `extern mod rustv`) into executable builds (similarly to how libstd is injected, tunable via `#[no_uv]`) to bring in the "rust blessed event loop implementation."
Codegen-wise, there is a new `event_loop_factory` language item which is tagged on a function with 0 arguments returning `~EventLoop`. This function's symbol is then inserted into the crate map for an executable crate, and if there is no definition of the `event_loop_factory` language item then the value is null.
What this means is that embedding rust as a library in another language just got a little harder. Libraries don't have crate maps, which means that there's no way to find the event loop implementation to spin up the runtime. That being said, it's always possible to build the runtime manually. This request also makes more runtime components public which should probably be public anyway. This new public-ness should allow custom scheduler setups everywhere regardless of whether you follow the `rt::start `path.
The previous implementation, when combined with small discriminants and
immediate types, caused problems for types like `Either<u8, i16>` which
are now small enough to be immediate and can have fields intersecting
the highest-alignment variant's alignment padding (which LLVM doesn't
preserve). So let's not do that.
Not only can discriminants be smaller than int now, but they can be
larger than int on 32-bit targets. This has obvious implications for the
reflection interface. Without this change, things fail with LLVM
assertions when we try to "extend" i64 to i32.
Note that raising an error during trans doesn't stop the compile or cause
rustc to exit with a failure status, currently, so this is of more than
cosmetic importance.
Allows an enum with a discriminant to use any of the primitive integer
types to store it. By default the smallest usable type is chosen, but
this can be overridden with an attribute: `#[repr(int)]` etc., or
`#[repr(C)]` to match the target's C ABI for the equivalent C enum.
This commit breaks a few things, due to transmutes that now no longer
match in size, or u8 enums being passed to C that expects int, or
reflection; later commits on this branch fix them.
There are a few reasons that this is a desirable move to take:
1. Proof of concept that a third party event loop is possible
2. Clear separation of responsibility between rt::io and the uv-backend
3. Enforce in the future that the event loop is "pluggable" and replacable
Here's a quick summary of the points of this pull request which make this
possible:
* Two new lang items were introduced: event_loop, and event_loop_factory.
The idea of a "factory" is to define a function which can be called with no
arguments and will return the new event loop as a trait object. This factory
is emitted to the crate map when building an executable. The factory doesn't
have to exist, and when it doesn't then an empty slot is in the crate map and
a basic event loop with no I/O support is provided to the runtime.
* When building an executable, then the rustuv crate will be linked by default
(providing a default implementation of the event loop) via a similar method to
injecting a dependency on libstd. This is currently the only location where
the rustuv crate is ever linked.
* There is a new #[no_uv] attribute (implied by #[no_std]) which denies
implicitly linking to rustuv by default
Closes#5019
