Refactored code so that the drop-flag values for initialized
(`DTOR_NEEDED`) versus dropped (`DTOR_DONE`) are given explicit names.
Add `mem::dropped()` (which with `DTOR_DONE == 0` is semantically the
same as `mem::zeroed`, but the point is that it abstracts away from
the particular choice of value for `DTOR_DONE`).
Filling-drop needs to use something other than `ptr::read_and_zero`,
so I added such a function: `ptr::read_and_drop`. But, libraries
should not use it if they can otherwise avoid it.
Fixes to tests to accommodate filling-drop.
For the rust-call ABI, the last function argument is a tuple that gets
untupled for the actual call. For bare functions using this ABI, the
code has access to the tuple, so we need to tuple the arguments again.
But closures can't actually access the tuple. Their arguments map to the
elements in the tuple. So what we currently do is to tuple the arguments
and then immediately untuple them again, which is pretty useless and we
can just omit it.
This is a [breaking-change]. When indexing a generic map (hashmap, etc) using the `[]` operator, it is now necessary to borrow explicitly, so change `map[key]` to `map[&key]` (consistent with the `get` routine). However, indexing of string-valued maps with constant strings can now be written `map["abc"]`.
r? @japaric
cc @aturon @Gankro
For the rust-call ABI, the last function argument is a tuple that gets
untupled for the actual call. For bare functions using this ABI, the
code has access to the tuple, so we need to tuple the arguments again.
But closures can't actually access the tuple. Their arguments map to the
elements in the tuple. So what we currently do is to tuple the arguments
and then immediately untuple them again, which is pretty useless and we
can just omit it.
Boolean values and small aggregates have a different type in
args/allocas than in SSA values but the intrinsics for volatile and
atomic ops were missing the necessary casts to handle that.
Fixes#23550
This includes a slight refactoring of the `cast_shift_rhs` and related
functions in `trans::base`, so that I can call them from much later in
the compiler's control flow (so that we can clearly dilineate where
automatic conversions of the RHS occur, versus where we check it).
The rhs-checking and fallback-masking is generalized to 8- and 16-bit
values, and the fallback-masking is turned on unconditionally.
Fix#10183.
Is this a [breaking-change]? I would argue it is not; it only adds a
strict definition to what was previously undefined behavior; however,
there might be code that was e.g. assuming that `1_i8 << 17` yields 0.
(This happens in certain contexts and at certain optimization levels.)
* no_split_stack was renamed to no_stack_check
* deriving was renamed to derive
* `use foo::mod` was renamed to `use foo::self`;
* legacy lifetime definitions in closures have been replaced with `for` syntax
* `fn foo() -> &A + B` has been deprecated for some time (needs parens)
* Obsolete `for Sized?` syntax
* Obsolete `Sized? Foo` syntax
* Obsolete `|T| -> U` syntax
This removes the error case of the compression functions, the only errors that
can occur are incorrect parameters or an out-of-memory condition, both of which
are handled with panics in Rust.
Also introduces an extensible `Error` type instead of returning an `Option`.
When this attribute is applied to a function, its return value gets the
noalias attribute, which is how you tell LLVM that the function returns
a \"new\" pointer that doesn't alias anything accessible to the caller,
i.e. it acts like a memory allocator.
Plain malloc doesn't need this attribute because LLVM already knows
about malloc and adds the attribute itself.
When this attribute is applied to a function, its return value gets the
noalias attribute, which is how you tell LLVM that the function returns
a "new" pointer that doesn't alias anything accessible to the caller,
i.e. it acts like a memory allocator.
Plain malloc doesn't need this attribute because LLVM already knows
about malloc and adds the attribute itself.
This commit is an implementation of [RFC 563][rfc] which adds a new
`cfg(debug_assertions)` directive which is specially recognized and calculated
by the compiler. The flag is turned off at any optimization level greater than 1
and may also be explicitly controlled through the `-C debug-assertions`
flag.
[rfc]: https://github.com/rust-lang/rfcs/pull/563
The `debug_assert!` and `debug_assert_eq!` macros now respect this instead of
the `ndebug` variable and `ndebug` no longer holds any meaning to the standard
library.
Code which was previously relying on `not(ndebug)` to gate expensive code should
be updated to rely on `debug_assertions` instead.
Closes#22492
[breaking-change]
This commit is an implementation of [RFC 563][rfc] which adds a new
`cfg(debug_assertions)` directive which is specially recognized and calculated
by the compiler. The flag is turned off at any optimization level greater than 1
and may also be explicitly controlled through the `-C debug-assertions`
flag.
[rfc]: https://github.com/rust-lang/rfcs/pull/563
The `debug_assert!` and `debug_assert_eq!` macros now respect this instead of
the `ndebug` variable and `ndebug` no longer holds any meaning to the standard
library.
Code which was previously relying on `not(ndebug)` to gate expensive code should
be updated to rely on `debug_assertions` instead.
Closes#22492
[breaking-change]
Many of the modifications putting in `Box::new` calls also include a
pointer to Issue 22405, which tracks going back to `box <expr>` if
possible in the future.
(Still tried to use `Box<_>` where it sufficed; thus some tests still
have `box_syntax` enabled, as they use a mix of `box` and `Box::new`.)
Precursor for overloaded-`box` and placement-`in`; see Issue 22181.
Rebase and follow-through on work done by @cmr and @aatch.
Implements most of rust-lang/rfcs#560. Errors encountered from the checks during building were fixed.
The checks for division, remainder and bit-shifting have not been implemented yet.
See also PR #20795
cc @Aatch ; cc @nikomatsakis
Adds overflow checking to integer addition, multiplication, and subtraction
when `-Z force-overflow-checks` is true, or if `--cfg ndebug` is not passed to
the compiler. On overflow, it panics with `arithmetic operation overflowed`.
Also adds `overflowing_add`, `overflowing_sub`, and `overflowing_mul`
intrinsics for doing unchecked arithmetic.
[breaking-change]
type-outlives works for closure types so that it ensures that all upvars
outlive the region in question. This gives the same guarantees but
without introducing artificial regions (and gives better error messages
to boot).
static_assert is documented as working on static with type `bool`, but
we currently accept it on any const static and crash when the const has
an non-integral type.
This is a breaking-change for anyone who used static_assert on types
likes i32, which happened to work but seems like an unintended
consequence of the missing error checking.
[breaking-change]
Fixes#22056
static_assert is documented as working on static with type `bool`, but
we currently accept it on any const static and crash when the const has
an non-integral type.
This is a breaking-change for anyone who used static_assert on types
likes i32, which happened to work but seems like an unintended
consequence of the missing error checking.
[breaking-change]
Fixes#22056
aatch's cfg revisions, namely to match expressions
Revise handling of match expressions so that arms branch to next arm.
Update the graphviz tests accordingly.
Fixes#22073. (Includes regression test for the issue.)
This commit is an implementation of [RFC 592][r592] and [RFC 840][r840]. These
two RFCs tweak the behavior of `CString` and add a new `CStr` unsized slice type
to the module.
[r592]: https://github.com/rust-lang/rfcs/blob/master/text/0592-c-str-deref.md
[r840]: https://github.com/rust-lang/rfcs/blob/master/text/0840-no-panic-in-c-string.md
The new `CStr` type is only constructable via two methods:
1. By `deref`'ing from a `CString`
2. Unsafely via `CStr::from_ptr`
The purpose of `CStr` is to be an unsized type which is a thin pointer to a
`libc::c_char` (currently it is a fat pointer slice due to implementation
limitations). Strings from C can be safely represented with a `CStr` and an
appropriate lifetime as well. Consumers of `&CString` should now consume `&CStr`
instead to allow producers to pass in C-originating strings instead of just
Rust-allocated strings.
A new constructor was added to `CString`, `new`, which takes `T: IntoBytes`
instead of separate `from_slice` and `from_vec` methods (both have been
deprecated in favor of `new`). The `new` method returns a `Result` instead of
panicking. The error variant contains the relevant information about where the
error happened and bytes (if present). Conversions are provided to the
`io::Error` and `old_io::IoError` types via the `FromError` trait which
translate to `InvalidInput`.
This is a breaking change due to the modification of existing `#[unstable]` APIs
and new deprecation, and more detailed information can be found in the two RFCs.
Notable breakage includes:
* All construction of `CString` now needs to use `new` and handle the outgoing
`Result`.
* Usage of `CString` as a byte slice now explicitly needs a `.as_bytes()` call.
* The `as_slice*` methods have been removed in favor of just having the
`as_bytes*` methods.
Closes#22469Closes#22470
[breaking-change]
