More work on opt-in built in traits. `Send` and `Sync` are not opt-in, `OwnedPtr` renamed to `UniquePtr` and the `Send` and `Sync` traits are now unsafe.
NOTE: This likely needs to be rebased on top of the yet-to-land snapshot.
r? @nikomatsakis
cc #13231
Various refactorings simplifying the mem-categorization and regionck interface. This is working towards an improvement for closure-and-upvar-mode inference.
r? @eddyb
There is also some work here to make resolve a bit more stable - it no longer overwrites a specific import with a glob import.
[breaking-change]
Import shadowing of single/list imports by globs is now forbidden. An interesting case is where a glob import imports a re-export (`pub use`) of a single import. This still counts as a single import for the purposes of shadowing .You can usually fix any bustage by re-ordering such imports. A single import may still shadow (override) a glob import or the prelude.
... really this time `:)`
I went for the simpler fix after all since it turned out to become a bit too complicated to extract the current iteration value from its containing `Option` with the different memory layouts it can have. It's also what we already do for match bindings.
I also extended the new test case to include the "simple identifier" case.
Fixes#20127, fixes#19732
The previous behaviour of using the smallest type possible caused LLVM
to treat padding too conservatively, causing poor codegen. This commit
changes the behaviour to use an alignment-sized integer as the
discriminant. This keeps types the same size, but helps LLVM understand
the data structure a little better, resulting in better codegen.
This commit adds support for the compiler to distinguish between different forms
of lookup paths in the compiler itself. Issue #19767 has some background on this
topic, as well as some sample bugs which can occur if these lookup paths are not
separated.
This commits extends the existing command line flag `-L` with the same trailing
syntax as the `-l` flag. Each argument to `-L` can now have a trailing `:all`,
`:native`, `:crate`, or `:dependency`. This suffix indicates what form of lookup
path the compiler should add the argument to. The `dependency` lookup path is
used when looking up crate dependencies, the `crate` lookup path is used when
looking for immediate dependencies (`extern crate` statements), and the `native`
lookup path is used for probing for native libraries to insert into rlibs. Paths
with `all` are used for all of these purposes (the default).
The default compiler lookup path (the rustlib libdir) is by default added to all
of these paths. Additionally, the `RUST_PATH` lookup path is added to all of
these paths.
Closes#19767
The previous behaviour of using the smallest type possible caused LLVM
to treat padding too conservatively, causing poor codegen. This commit
changes the behaviour to use an type-alignment-sized integer as the
discriminant. This keeps types the same size, but helps LLVM understand
the data structure a little better, resulting in better codegen.
post-unboxed-closure-conversion. This requires a fair amount of
annoying coercions because all the `map` etc types are defined
generically over the `F`, so the automatic coercions don't propagate;
this is compounded by the need to use `let` and not `as` due to
stage0. That said, this pattern is to a large extent temporary and
unusual.
Back when for-loop iteration variables were just de-sugared into `let` bindings, debuginfo for them was created like for any other `let` binding. When the implementation approach for for-loops changed, we ceased having debuginfo for the iteration variable. This PR fixes this omission and adds a more prominent test case for it.
Also contains some minor, general cleanup of the debuginfo module.
Fixes#19732
#16081 fixed an issue where a nested return statement would cause incorrect behaviour due to the inner return writing over the return stack slot that had already been written too. However, the check was very broad and picked many cases that wouldn't ever be affected by this issue.
As a result, the number of allocas increased dramatically and therefore stack-size increased. LLVM is not able to remove all of the extraneous allocas. Any code that had multiple return values in a compound expression at the end of a function (including loops) would be hit by the issue.
The check now uses a control-flow graph to only consider the case when the inner return is executed conditionally. By itself, this narrowed definition causes #15763 to return, so the control-flow graph is also used to avoid passing the return slot as a destination when the result won't be used.
This change allows the stack-size of the main rustc task to be reduced to 8MB from 32MB.
This commit shuffles around some CLI flags of the compiler to some more stable
locations with some renamings. The changes made were:
* The `-v` flag has been repurposes as the "verbose" flag. The version flag has
been renamed to `-V`.
* The `-h` screen has been split into two parts. Most top-level options (not
all) show with `-h`, and the remaining options (generally obscure) can be
shown with `--help -v` which is a "verbose help screen"
* The `-V` flag (version flag now) has lost its argument as it is now requested
with `rustc -vV` "verbose version".
* The `--emit` option has had its `ir` and `bc` variants renamed to `llvm-ir`
and `llvm-bc` to emphasize that they are LLVM's IR/bytecode.
* The `--emit` option has grown a new variant, `dep-info`, which subsumes the
`--dep-info` CLI argument. The `--dep-info` flag is now deprecated.
* The `--parse-only`, `--no-trans`, `--no-analysis`, and `--pretty` flags have
moved behind the `-Z` family of flags.
* The `--debuginfo` and `--opt-level` flags were moved behind the top-level `-C`
flag.
* The `--print-file-name` and `--print-crate-name` flags were moved behind one
global `--print` flag which now accepts one of `crate-name`, `file-names`, or
`sysroot`. This global `--print` flag is intended to serve as a mechanism for
learning various metadata about the compiler itself.
* The top-level `--pretty` flag was moved to a number of `-Z` options.
No warnings are currently enabled to allow tools like Cargo to have time to
migrate to the new flags before spraying warnings to all users.
cc https://github.com/rust-lang/rust/issues/19051
This commit shuffles around some CLI flags of the compiler to some more stable
locations with some renamings. The changes made were:
* The `-v` flag has been repurposes as the "verbose" flag. The version flag has
been renamed to `-V`.
* The `-h` screen has been split into two parts. Most top-level options (not
all) show with `-h`, and the remaining options (generally obscure) can be
shown with `--help -v` which is a "verbose help screen"
* The `-V` flag (version flag now) has lost its argument as it is now requested
with `rustc -vV` "verbose version".
* The `--emit` option has had its `ir` and `bc` variants renamed to `llvm-ir`
and `llvm-bc` to emphasize that they are LLVM's IR/bytecode.
* The `--emit` option has grown a new variant, `dep-info`, which subsumes the
`--dep-info` CLI argument. The `--dep-info` flag is now deprecated.
* The `--parse-only`, `--no-trans`, and `--no-analysis` flags have
moved behind the `-Z` family of flags.
* The `--debuginfo` and `--opt-level` flags were moved behind the top-level `-C`
flag.
* The `--print-file-name` and `--print-crate-name` flags were moved behind one
global `--print` flag which now accepts one of `crate-name`, `file-names`, or
`sysroot`. This global `--print` flag is intended to serve as a mechanism for
learning various metadata about the compiler itself.
No warnings are currently enabled to allow tools like Cargo to have time to
migrate to the new flags before spraying warnings to all users.
Rewrite how the HRTB algorithm matches impls against obligations. Instead of impls providing higher-ranked trait-references, impls now once again only have early-bound regions. The skolemization checks are thus moved out into trait matching itself. This allows to implement "perfect forwarding" impls like those described in #19730. This PR builds on a previous PR that was already reviewed by @pnkfelix.
r? @pnkfelix
Fixes#19730
