Macro desugaring of `in PLACE { BLOCK }` into "simpler" expressions following the in-development "Placer" protocol.
Includes Placer API that one can override to integrate support for `in` into one's own type. (See [RFC 809].)
[RFC 809]: https://github.com/rust-lang/rfcs/blob/master/text/0809-box-and-in-for-stdlib.md
Part of #22181
Replaced PR #26180.
Turns on the `in PLACE { BLOCK }` syntax, while leaving in support for the old `box (PLACE) EXPR` syntax (since we need to support that at least until we have a snapshot with support for `in PLACE { BLOCK }`.
(Note that we are not 100% committed to the `in PLACE { BLOCK }` syntax. In particular I still want to play around with some other alternatives. Still, I want to get the fundamental framework for the protocol landed so we can play with implementing it for non `Box` types.)
----
Also, this PR leaves out support for desugaring-based `box EXPR`. We will hopefully land that in the future, but for the short term there are type-inference issues injected by that change that we want to resolve separately.
is being used now before the final regionck stage and in some cases SOME
amount of unresolved inference is OK. In fact, we could probably just
allow inference variables as well with only minimal pain.
TyClosure variant; thread this through wherever closure substitutions
are expected, which leads to a net simplification. Simplify trans
treatment of closures in particular.
Currently, `rustc` generates nondeterministic archives, which contain system timestamps. These don't really serve any useful purpose, and enabling deterministic archives moves us a little closer to completely deterministic builds. For a small toy library using `std::ops::{Deref,DerefMut}`, this change actually results in a bit-for-bit identical build every time.
Currently you can hit a link error on MSVC by only referencing static items from
a crate (no functions for example) and then link to the crate statically (as all
Rust crates do 99% of the time). A detailed investigation can be found [on
github][details], but the tl;dr is that we need to stop applying dllimport so
aggressively.
This commit alters the application of dllimport on constants to only cases where
the crate the constant originated from will be linked as a dylib in some output
crate type. That way if we're just linking rlibs (like the motivation for this
issue) we won't use dllimport. For the compiler, however, (which has lots of
dylibs) we'll use dllimport.
[details]: https://github.com/rust-lang/rust/issues/26591#issuecomment-123513631
cc #26591
Adds support to the configure script for detecting Visual Studio 2015 being
installed and builds LLVM/uses cl with that compiler. The compiler will
automatically use this MSVC linker anyway because it's the highest version.
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.
The LTO pass in the compiler forgot to call the `LLVMRustAddBuilderLibraryInfo`
function and configure other options such as merge_functions, vectorize_slp,
etc. This ended up causing linker errors on MSVC targets because the optimizer
didn't have the right knowledge that some system functions are missing on these
platforms.
This commit consolidates creation of PassManagerBuilder instances to one
function which is then called when needed. This ensures that the pass manager is
always correctly configured with the various target-specific information that
LLVM needs.
Overall, this fixes `-C lto -C opt-level=3` on 32-bit MSVC targets.
When compiling libsyntax this removes about 30k basic blocks that only
contain a single unconditional jump and reduces the peak memory usage by
about 10MB (from 681MB down to 671MB).
