I needed it in `RawVec`, `Vec`, and `TypedArena` for `rustc` to
bootstrap; but of course that alone was not sufficient for `make
check`.
Later I added `unsafe_destructor_blind_to_params` to collections, in
particular `LinkedList` and `RawTable` (the backing representation for
`HashMap` and `HashSet`), to get the regression tests exercising
cyclic structure from PR #27185 building.
----
Note that the feature is `dropck_parametricity` (which is not the same
as the attribute's name). We will almost certainly vary our strategy
here in the future, so it makes some sense to have a not-as-ugly name
for the feature gate. (The attribute name was deliberately selected to
be ugly looking.)
Implement cannot-assume-parametricity (CAP) from RFC 1238, and add the
UGEH attribute.
----
Note that we check for the attribute attached to the dtor method, not
the Drop impl.
(This is just to match the specification of RFC and the tests; I am
not wedded to this approach.)
paths, and construct paths for all definitions. Also, stop rewriting
DefIds for closures, and instead just load the closure data from
the original def-id, which may be in another crate.
This PR removes random remaining `Ident`s outside of libsyntax and performs general cleanup
In particular, interfaces of `Name` and `Ident` are tidied up, `Name`s and `Ident`s being small `Copy` aggregates are always passed to functions by value, and `Ident`s are never used as keys in maps, because `Ident` comparisons are tricky.
Although this PR closes https://github.com/rust-lang/rust/issues/6993 there's still work related to it:
- `Name` can be made `NonZero` to compress numerous `Option<Name>`s and `Option<Ident>`s but it requires const unsafe functions.
- Implementation of `PartialEq` on `Ident` should be eliminated and replaced with explicit hygienic, non-hygienic or member-wise comparisons.
- Finally, large parts of AST can potentially be converted to `Name`s in the same way as HIR to clearly separate identifiers used in hygienic and non-hygienic contexts.
r? @nrc
This adds a new target property, `target_vendor`. It is to be be used as a matcher for conditional compilation. The vendor is part of the [autoconf target triple](http://llvm.org/docs/doxygen/html/classllvm_1_1Triple.html#details): `<arch><sub>-<vendor>-<os>-<env>`. `arch`, `target_os` and `target_env` are already supported by Rust.
This change was suggested in PR #28593. It enables conditional compilation based on the vendor. This is needed for the rumprun target, which needs to match against both, target_os and target_vendor.
The default value for `target_vendor` is "unknown", "apple" and "pc" are other common values.
Matching against the `target_vendor` is introduced behind the feature gate `#![feature(cfg_target_vendor)]`.
This is the first time I messed around with rustc internals. I just added the my code where I found the existing `target_*` variables, hopefully I haven't missed anything. Please review with care. :)
r? @alexcrichton
Make sure Name, SyntaxContext and Ident are passed by value
Make sure Idents don't serve as keys (or parts of keys) in maps, Ident comparison is not well defined
This adds a new target property, `target_vendor` which can be used as a
matcher for conditional compilation. The vendor is part of the autoconf
target triple: <arch><sub>-<vendor>-<os>-<env>
The default value for `target_vendor` is "unknown".
Matching against the `target_vendor` with `#[cfg]` is currently feature
gated as `cfg_target_vendor`.
This reduces some clones of `Vec`s. These are not deep copies since the
token tree is made using `Rc`s, so this won't be a major improvement.
r? @eddyb
The second commit in this PR will stop printing the macro definition site in backtraces, which cuts their length in half and increases readability (the definition site was only correct for local macros).
The third commit will not print an invocation if the last one printed occurred at the same place (span). This will make backtraces caused by a self-recursive macro much shorter.
(A possible alternative would be to capture the backtrace first, then limit it to a few frames at the start and end of the chain and print `...` inbetween. This would also work with multiple macros calling each other, which is not addressed by this PR - although the backtrace will still be halved)
Example:
```rust
macro_rules! m {
( 0 $($t:tt)* ) => ( m!($($t)*); );
() => ( fn main() {0} );
}
m!(0 0 0 0 0 0 0 0 0 0 0 0 0 0 0);
```
On a semi-recent nightly, this yields:
```
test.rs:3:21: 3:22 error: mismatched types:
expected `()`,
found `_`
(expected (),
found integral variable) [E0308]
test.rs:3 () => ( fn main() {0} );
^
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:2:23: 2:34 note: expansion site
test.rs:1:1: 4:2 note: in expansion of m!
test.rs:6:1: 6:35 note: expansion site
test.rs:3:21: 3:22 help: run `rustc --explain E0308` to see a detailed explanation
error: aborting due to previous error
```
After this patch:
```
test.rs:3:21: 3:22 error: mismatched types:
expected `()`,
found `_`
(expected (),
found integral variable) [E0308]
test.rs:3 () => ( fn main() {0} );
^
test.rs:2:23: 2:34 note: in this expansion of m!
test.rs:6:1: 6:35 note: in this expansion of m!
test.rs:3:21: 3:22 help: run `rustc --explain E0308` to see a detailed explanation
error: aborting due to previous error
```
This allows to skip the codegen for all the unneeded landing pads, reducing code size across the board by about 2-5%, depending on the crate. Compile times seem to be pretty unaffected though :-/
There is a dead code in libsyntax/parser/parse.rs, when parsing structs.
Two functions are involved:
* [parse_item_struct](cd9c9f048f/src/libsyntax/parse/parser.rs (L4691))
* [parse_tuple_struct_body](cd9c9f048f/src/libsyntax/parse/parser.rs (L4769))
The problem is that both functions handle the case with unit structs. But because
`parse_tuple_struct_body` is called from `parse_item_struct`, it never faces
this case.
This PR removes unit struct case from `parse_tuple_struct_body` function. I tested with `make -j8 check-statge1`.
This halves the backtrace length. The definition site wasn't very useful
anyways, since it may be invalid (for compiler expansions) or located in
another crate. Since the macro name is still printed, grepping for it is
still an easy way of finding the definition.
Both `parse_tuple_struct_body` and `parse_item_struct` handled the case
of unit like struct. The redundancy is removed,
`parse_tuple_struct_body` now handles only real tuple structs.
This commit is an implementation of [RFC 1212][rfc] which tweaks the behavior of
the `str::lines` and `BufRead::lines` iterators. Both iterators now account for
`\r\n` sequences in addition to `\n`, allowing for less surprising behavior
across platforms (especially in the `BufRead` case). Splitting *only* on the
`\n` character can still be achieved with `split('\n')` in both cases.
The `str::lines_any` function is also now deprecated as `str::lines` is a
drop-in replacement for it.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1212-line-endings.mdCloses#28032
This commit is an implementation of [RFC 1212][rfc] which tweaks the behavior of
the `str::lines` and `BufRead::lines` iterators. Both iterators now account for
`\r\n` sequences in addition to `\n`, allowing for less surprising behavior
across platforms (especially in the `BufRead` case). Splitting *only* on the
`\n` character can still be achieved with `split('\n')` in both cases.
The `str::lines_any` function is also now deprecated as `str::lines` is a
drop-in replacement for it.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1212-line-endings.mdCloses#28032
r? @nikomatsakis
Trying to land this first stab, which basically just duplicates the AST. Will file issues for the various things I've got in mind to improve.
This is a [breaking-change] for syntax extension authors. The fix is to use MultiModifier or MultiDecorator, which have the same functionality but are more flexible. Users of syntax extensions are unaffected.
This is a [breaking-change] for syntax extension authors. The fix is to use MultiModifier or MultiDecorator, which have the same functionality but are more flexible. Users of syntax extensions are unaffected.
We were using them for every expansion, instead of using `Name`.
Also converted `CompilerExpansion` into an enum so its nicer to use and takes up less space.
Will profile later, but this should be a small improvement in memory usage.
r? @eddyb
This handles the case where the #[main] function is buried deeper in
the ast than we search for #[test] functions. I'm not sure why one
would want to do that, but since it works in standard compilation it
should also work for tests.
Since enums are namespaced now, should we also remove the `Fk` prefixes from `FnKind` and remove the reexport? (The reexport must be removed because otherwise it clashes with glob imports containing `ItemFn`). IMO writing `FnKind::Method` is much clearer than `FkMethod`.
The methods gave wrong results for TyIs and TyUs, whose suffix len
should be 5 nowadays. But since they were only used for parsing,
and unneeded for that since 606a309d, remove them rather than fixing.
I hope this is ok to do, since all of rustc is considered unstable...
In the case where there are no paren in the AST, the pretty printer doesn't correctly print binary operations where precedence is concerned. Parenthesis may be missing due to some kind of expansion or manipulation of the AST.
Example:
Pretty printer prints Expr(*, Expr(+, 1, 1), 2) as 1 + 1 * 2, as opposed to (1 + 1) * 2
r? @nrc
The methods gave wrong results for TyIs and TyUs, whose suffix len
should be 5 nowadays. But since they were only used for parsing,
and unneeded for that since 606a309d, remove them rather than fixing.
This is purposely separate to the "rust-intrinsic" ABI, because these
intrinsics are theoretically going to become stable, and should be fine
to be independent of the compiler/language internals since they're
intimately to the platform.
This is theoretically a breaking change, but GitHub search turns up no
uses of it, and most non-built-in cfg's are passed via cargo features,
which look like `feature = "..."`, and hence can't overlap.
This commit turns `#[unstable]` attributes missing an `issue` annotation into a hard error. This will require the libs team to ensure that there's a tracking issue for all unstable features in the standard library.
All existing unstable features have had issues created and they've all been updated. Yay!
Closes#26868
Just a little code cleanup I was doing as part of another refactoring (which may turn out not to be needed). The main thrust of this is to cleanup the interface to `tydecode.rs` to be less ridiculously repetitive. I also purged the generic "def-id conversion" parameter in favor of a trait object, just to reduce code duplication a bit and make the signatures a bit less messy. I measured the bootstrapping time to build stage2 with these changes, it was identical. (But it'd be easy enough to restore the unboxed closure if we wanted it.)
This turns an `#[unstable]` tag without an `issue` annotation into a hard error
to ensure that we've always got a tracking issue for unstable features in the
standard library.
Current behaviour demo: http://is.gd/l3FEgo
(The span is printed at the start of the source code)
This patch moves the span to the use of `$i` in the macro rhs (as the code comment already claims)
This commit is an implementation of [RFC 1183][rfc] which allows swapping out
the default allocator on nightly Rust. No new stable surface area should be
added as a part of this commit.
[rfc]: https://github.com/rust-lang/rfcs/pull/1183
Two new attributes have been added to the compiler:
* `#![needs_allocator]` - this is used by liballoc (and likely only liballoc) to
indicate that it requires an allocator crate to be in scope.
* `#![allocator]` - this is a indicator that the crate is an allocator which can
satisfy the `needs_allocator` attribute above.
The ABI of the allocator crate is defined to be a set of symbols that implement
the standard Rust allocation/deallocation functions. The symbols are not
currently checked for exhaustiveness or typechecked. There are also a number of
restrictions on these crates:
* An allocator crate cannot transitively depend on a crate that is flagged as
needing an allocator (e.g. allocator crates can't depend on liballoc).
* There can only be one explicitly linked allocator in a final image.
* If no allocator is explicitly requested one will be injected on behalf of the
compiler. Binaries and Rust dylibs will use jemalloc by default where
available and staticlibs/other dylibs will use the system allocator by
default.
Two allocators are provided by the distribution by default, `alloc_system` and
`alloc_jemalloc` which operate as advertised.
Closes#27389
This PR implements the majority of RFC 1214. In particular, it implements:
- the new outlives relation
- comprehensive WF checking
For the most part, new code receives warnings, not errors, though 3 regressions were found via a crater run.
There are some deviations from RFC 1214. Most notably:
- we still consider implied bounds from fn ret; this intersects other soundness issues that I intend to address in detail in a follow-up RFC. Fixing this without breaking a lot of code probably requires rewriting compare-method somewhat (which is probably a good thing).
- object types do not check trait bounds for fear of encountering `Self`; this was left as an unresolved question in RFC 1214, but ultimately feels inconsistent.
Both of those two issues are highlighted in the tracking issue, https://github.com/rust-lang/rust/issues/27579. #27579 also includes a testing matrix with new tests that I wrote -- these probably duplicate some existing tests, I tried to check but wasn't quite sure what to look for. I tried to be thorough in testing the WF relation, at least, but would welcome suggestions for missing tests.
r? @nrc (or perhaps someone else?)
This commit removes all unstable and deprecated functions in the standard
library. A release was recently cut (1.3) which makes this a good time for some
spring cleaning of the deprecated functions.
This commit removes all unstable and deprecated functions in the standard
library. A release was recently cut (1.3) which makes this a good time for some
spring cleaning of the deprecated functions.
To correctly reexport statically included libraries from a DLL on Windows, the
compiler will soon need to have knowledge about what symbols are statically
included and which are not. To solve this problem a new unstable
`#[linked_from]` attribute is being added and recognized on `extern` blocks to
indicate which native library the symbols are coming from.
The compiler then keeps track of what the set of FFI symbols are that are
included statically. This information will be used in a future commit to
configure how we invoke the linker on Windows.
This commit removes all morestack support from the compiler which entails:
* Segmented stacks are no longer emitted in codegen.
* We no longer build or distribute libmorestack.a
* The `stack_exhausted` lang item is no longer required
The only current use of the segmented stack support in LLVM is to detect stack
overflow. This is no longer really required, however, because we already have
guard pages for all threads and registered signal handlers watching for a
segfault on those pages (to print out a stack overflow message). Additionally,
major platforms (aka Windows) already don't use morestack.
This means that Rust is by default less likely to catch stack overflows because
if a function takes up more than one page of stack space it won't hit the guard
page. This is what the purpose of morestack was (to catch this case), but it's
better served with stack probes which have more cross platform support and no
runtime support necessary. Until LLVM supports this for all platform it looks
like morestack isn't really buying us much.
cc #16012 (still need stack probes)
Closes#26458 (a drive-by fix to help diagnostics on stack overflow)
r? @brson
This commit removes all morestack support from the compiler which entails:
* Segmented stacks are no longer emitted in codegen.
* We no longer build or distribute libmorestack.a
* The `stack_exhausted` lang item is no longer required
The only current use of the segmented stack support in LLVM is to detect stack
overflow. This is no longer really required, however, because we already have
guard pages for all threads and registered signal handlers watching for a
segfault on those pages (to print out a stack overflow message). Additionally,
major platforms (aka Windows) already don't use morestack.
This means that Rust is by default less likely to catch stack overflows because
if a function takes up more than one page of stack space it won't hit the guard
page. This is what the purpose of morestack was (to catch this case), but it's
better served with stack probes which have more cross platform support and no
runtime support necessary. Until LLVM supports this for all platform it looks
like morestack isn't really buying us much.
cc #16012 (still need stack probes)
Closes#26458 (a drive-by fix to help diagnostics on stack overflow)
