Add `#[rustc_error]` annotation, which causes trans to signal an error
if found on the `main()` function. This lets you write tests that live
in `compile-fail` but are expected to compile successfully. This is
handy when you have many small variations on a theme that you want to
keep together, and you are just testing the type checker, not the
runtime semantics.
r? @pnkfelix
This is super black magic internals at the moment, but having it
somewhere semi-public seems good. The current versions weren't being
rendered, and they'll be useful for some people.
Fixes#21281
r? @nikomatsakis @kmcallister
if found on the `main()` function. This lets you write tests that live
in `compile-fail` but are expected to compile successfully. This is
handy when you have many small variations on a theme that you want to
keep together, and you are just testing the type checker, not the
runtime semantics.
immediately surrounding a node that is a terminating_scope
(e.g. statements, looping forms) during which the destructors run (the
destructors for temporaries from the execution of that node, that is).
Introduced DestructionScopeData newtype wrapper around ast::NodeId, to
preserve invariant that FreeRegion and ScopeChain::BlockScope carry
destruction scopes (rather than arbitrary CodeExtents).
Insert DestructionScope and block Remainder into enclosing CodeExtents
hierarchy.
Add more doc for DestructionScope, complete with ASCII art.
Switch to constructing DestructionScope rather than Misc in a number
of places, mostly related to `ty::ReFree` creation, and use
destruction-scopes of node-ids at various calls to
liberate_late_bound_regions.
middle::resolve_lifetime: Map BlockScope to DestructionScope in `fn resolve_free_lifetime`.
Add the InnermostDeclaringBlock and InnermostEnclosingExpr enums that
are my attempt to clarify the region::Context structure, and that
later commmts build upon.
Improve the debug output for `CodeExtent` attached to `ty::Region::ReScope`.
Loosened an assertion in `rustc_trans::trans::cleanup` to account for
`DestructionScope`. (Perhaps this should just be switched entirely
over to `DestructionScope`, rather than allowing for either `Misc` or
`DestructionScope`.)
----
Even though the DestructionScope is new, this particular commit should
not actually change the semantics of any current code.
This is super black magic internals at the moment, but having it
somewhere semi-public seems good. The current versions weren't being
rendered, and they'll be useful for some people.
Fixes#21281
As the function comment already says, the types generated in the
foreign_signture function don't necessarily match the types used for a
corresponding rust function. Therefore we can't just use these types to
guide the translation of the wrapper function that bridges between the
external ABI and the rust ABI. Instead, we can query LLVM about the
types used in the rust function and use those to generate an appropriate
wrapper.
Fixes#21454
This was particularly helpful in the time just after OIBIT's
implementation to make sure things that were supposed to be Copy
continued to be, but it's now creates a lot of noise for types that
intentionally don't want to be Copy.
r? @alexcrichton
Currently \"k / 2\" generates one (k: uint) or two (k: int) \"br false,
...\" instructions and the corresponding basic blocks, producing quite
some noise and making the code unnecessarily hard to read.
Additionally we can skip translation if the code would end up
unreachable anyway.
This can be considered partial work on #8256.
The main observable change: macro expansion sometimes results in spans where `lo > hi`; so for now, when we have such a span, do not attempt to return a snippet result.
(Longer term, we might think about whether we could still present a snippet for the cases where this arises, e.g. perhaps by showing the whole macro as the snippet, assuming that is the sole cause of such spans; or by somehow looking up the closest AST node that holds both `lo` and `hi`, and showing that.)
As a drive-by, revised the API to return a `Result` rather than an `Option`, with better information-packed error value that should help us (and maybe also our users) identify the causes of such problems in the future. Ideally the call-sites that really want an actual snippet would be updated to catch the newly added `Err` case and print something meaningful about it, but that is not part of this PR.
This can be considered partial work on #8256.
The main observable change: macro expansion sometimes results in spans
where `lo > hi`; so for now, when we have such a span, do not attempt
to return a snippet result.
(Longer term, we might think about whether we could still present a
snippet for the cases where this arises, e.g. perhaps by showing the
whole macro as the snippet, assuming that is the sole cause of such
spans; or by somehow looking up the closest AST node that holds both
`lo` and `hi`, and showing that.)
As a drive-by, revised the API to return a `Result` rather than an
`Option`, with better information-packed error value that should help
us (and maybe also our users) identify the causes of such problems in
the future. Ideally the call-sites that really want an actual snippet
would be updated to catch the newly added `Err` case and print
something meaningful about it, but that is not part of this PR.
Currently "k / 2" generates one (k: uint) or two (k: int) "br false,
..." instructions and the corresponding basic blocks, producing quite
some noise and making the code unnecessarily hard to read.
Additionally we can skip translation if the code would end up
unreachable anyway.
This was particularly helpful in the time just after OIBIT's
implementation to make sure things that were supposed to be Copy
continued to be, but it's now creates a lot of noise for types that
intentionally don't want to be Copy.
This *almost* completes the job for #16440. The idea is that even if we do not know whether some closure type `C` implements `Fn` or `FnMut` (etc), we still know its argument and return types. So if we see an obligation `C : Fn(_0)`, we can unify `_0` with those argument types while still considering the obligation ambiguous and unsatisfied. This helps to make a lot of progress with type inference even before closure kind inference is done.
As part of this PR, the explicit `:` syntax is removed from the AST and completely ignored. We still infer the closure kind based on the expected type if that is available. There are several reasons for this. First, deciding the closure kind earlier is always better, as it allows us to make more progress. Second, this retains a (admittedly obscure) way for users to manually specify the closure kind, which is useful for writing tests if nothing else. Finally, there are still some cases where inference can fail, so it may be useful to have this manual override. (The expectation is that we will eventually revisit an explicit syntax for specifying the closure kind, but it will not be `:` and may be some sort of generalization of the `||` syntax to handle other traits as well.)
This commit does not *quite* fix#16640 because a snapshot is still needed to enable the obsolete syntax errors for explicit `&mut:` and friends.
r? @eddyb as he reviewed the prior patch in this direction
As part of [RFC 474](https://github.com/rust-lang/rfcs/pull/474), this
commit renames `std::path` to `std::old_path`, leaving the existing path
API in place to ease migration to the new one. Updating should be as
simple as adjusting imports, and the prelude still maps to the old path
APIs for now.
[breaking-change]
upgrade the inference based on expected type so that it is able to
infer the fn kind in isolation even if the full signature is not
available (and we could perhaps do better still in some cases, such as
extracting just the types of the arguments but not the return value).
Now that associated types are fully implemented the iterator adaptors only need
type parameters which are associated with actual storage. All other type
parameters can either be derived from these (e.g. they are an associated type)
or can be bare on the `impl` block itself.
This is a breaking change due to the removal of type parameters on these
iterator adaptors, but code can fairly easily migrate by just deleting the
relevant type parameters for each adaptor. Other behavior should not be
affected.
Closes#21839
[breaking-change]
Now that associated types are fully implemented the iterator adaptors only need
type parameters which are associated with actual storage. All other type
parameters can either be derived from these (e.g. they are an associated type)
or can be bare on the `impl` block itself.
This is a breaking change due to the removal of type parameters on these
iterator adaptors, but code can fairly easily migrate by just deleting the
relevant type parameters for each adaptor. Other behavior should not be
affected.
Closes#21839
[breaking-change]
