Add Pass manager for MIR
A new PR, since rebasing the original one (https://github.com/rust-lang/rust/pull/31448) properly was a pain. Since then there has been several changes most notable of which:
1. Removed the pretty-printing with `#[rustc_mir(graphviz/pretty)]`, mostly because we now have `--unpretty=mir`, IMHO that’s the direction we should expand this functionality into;
2. Reverted the infercx change done for typeck, because typeck can make an infercx for itself by being a `MirMapPass`
r? @nikomatsakis
Distinguish fn item types to allow reification from nothing to fn pointers.
The first commit is a rebase of #26284, except for files that have moved since.
This is a [breaking-change], due to:
* each FFI function has a distinct type, like all other functions currently do
* all generic parameters on functions are recorded in their item types, e.g.:
`size_of::<u8>` & `size_of::<i8>`'s types differ despite their identical signature.
* function items are zero-sized, which will stop transmutes from working on them
The first two cases are handled in most cases with the new coerce-unify logic,
which will combine incompatible function item types into function pointers,
at the outer-most level of if-else chains, match arms and array literals.
The last case is specially handled during type-checking such that transmutes
from a function item type to a pointer or integer type will continue to work for
another release cycle, but are being linted against. To get rid of warnings and
ensure your code will continue to compile, cast to a pointer before transmuting.
Fix incorrect trait privacy error
This PR fixes#21670 by using the crate metadata instead of `ExternalExports` to determine if an external item is public.
r? @nikomatsakis
There's a lot of stuff wrong with the representation of these types:
TyFnDef doesn't actually uniquely identify a function, TyFnPtr is used to
represent method calls, TyFnDef in the sub-expression of a cast isn't
correctly reified, and probably some other stuff I haven't discovered yet.
Splitting them seems like the right first step, though.
Show `cfg` as possible argument to `--print` and make it so that `--print cfg` also outputs the `target_feature`s.
Should I also extend `src/test/run-make/print-cfg/Makefile` to check that `target_feature`s are actually printed?
Gated cfg attributes are not available on the stable and beta release
channels, therefore they should not be presented to users of those
channels in order to avoid confusion.
The configuration returned by `config::build_configuration` needs to
be modified with `target_features::add_configuration` in order to also
contain the target features. This is already done for the
configuration used when compiling and when creating the documentation,
but was missing in the `cfg` printing code.
This commit adds support for *truly* unstable options in the compiler, as well
as adding warnings for the start of the deprecation path of
unstable-but-not-really options. Specifically, the following behavior is now in
place for handling unstable options:
* As before, an unconditional error is emitted if an unstable option is passed
and the `-Z unstable-options` flag is not present. Note that passing another
`-Z` flag does not require passing `-Z unstable-options` as well.
* New flags added to the compiler will be in the `Unstable` category as opposed
to the `UnstableButNotReally` category which means they will unconditionally
emit an error when used on stable.
* All current flags are in a category where they will emit warnings when used
that the option will soon be a hard error.
Also as before, it is intended that `-Z` is akin to `#![feature]` in a crate
where it is required to unlock unstable functionality. A nightly compiler which
is used without any `-Z` flags should only be exercising stable behavior.
r? @brson
cc @alexcrichton
I still need to add error code explanation test with this, but I can't figure out a way to generate the `.md` files in order to test example source codes.
Will fix#27328.
A spec like `#[cfg(foo(bar))]` is not allowed as an attribute. This
makes the same spec be rejected by the compiler if passed in as a
`--cfg` argument.
Fixes#31495
This commit is an implementation of the new compiler flags required by [RFC
1361][rfc]. This specifically adds a new `cfg` option to the `--print` flag to
the compiler. This new directive will print the defined `#[cfg]` directives by
the compiler for the target in question.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1361-cargo-cfg-dependencies.md
A spec like `#[cfg(foo(bar))]` is not allowed as an attribute. This
makes the same spec be rejected by the compiler if passed in as a
`--cfg` argument.
Fixes#31495
