* The lint visitor's visit_ty method did not recurse, and had a
reference to the now closed#10894
* The newly enabled recursion has only affected the `deprectated` lint
which now detects uses of deprecated items in trait impls and
function return types
* Renamed some references to `CowString` and `CowVec` to `Cow<str>` and
`Cow<[T]>`, respectively, which appear outside of the crate which
defines them
* Replaced a few instances of `InvariantType<T>` with
`PhantomData<Cell<T>>`
* Disabled the `deprecated` lint in several places that
reference/implement traits on deprecated items which will get cleaned
up in the future
* Unfortunately, this means that if a library declares
`#![deny(deprecated)]` and marks anything as deprecated, it will have
to disable the lint for any uses of said item, e.g. any impl the now
deprecated item
For any library that denies deprecated items but has deprecated items
of its own, this is a [breaking-change]
I had originally intended for the lint to ignore uses of deprecated items that are declared in the same crate, but this goes against some previous test cases that expect the lint to capture *all* uses of deprecated items, so I maintained the previous approach to avoid changing the expected behavior of the lint.
Tested locally on OS X, so hopefully there aren't any deprecated item uses behind a `cfg` that I may have missed.
1. Detect and report arithmetic overflow during const-expr eval.
2. Instead `eval_const_expr_partial` returning `Err(String)`, it now
has a dedicated enum of different cases. The main benefit of this
is the ability to pass along an interpretable payload, namely the
two inputs that caused an overlfow.
I attempted to minimize fallout to error output in tests, but some was
unavoidable. Those changes are in a follow-on commit.
This only replaces the conditional arith-overflow asserts with
unconditional errors from the guts of const-eval; it does *not*
attempt to sanely handle such errors e.g. with a nice error message
from `rustc`. So the same test that led me to add this commit are
still failing, and must be addressed.
During my clean-up of rebase errors, I took the opportunity to implement
parse_opt_bool so that it isn't identical to parse_bool wrapped in
`Some`.
parse_opt_bool considers no value to be true, a value of 'y', 'yes' or
'on' to be true and 'n', 'no' or 'off' to be false. All other values are
an error.
Many of the core rust libraries have places that rely on integer
wrapping behaviour. These places have been altered to use the wrapping_*
methods:
* core:#️⃣:sip - A number of macros
* core::str - The `maximal_suffix` method in `TwoWaySearcher`
* rustc::util::nodemap - Implementation of FnvHash
* rustc_back::sha2 - A number of macros and other places
* rand::isaac - Isaac64Rng, changed to use the Wrapping helper type
Some places had "benign" underflow. This is when underflow or overflow
occurs, but the unspecified value is not used due to other conditions.
* collections::bit::Bitv - underflow when `self.nbits` is zero.
* collections:#️⃣:{map,table} - Underflow when searching an empty
table. Did cause undefined behaviour in this case due to an
out-of-bounds ptr::offset based on the underflowed index. However the
resulting pointers would never be read from.
* syntax::ext::deriving::encodable - Underflow when calculating the
index of the last field in a variant with no fields.
These cases were altered to avoid the underflow, often by moving the
underflowing operation to a place where underflow could not happen.
There was one case that relied on the fact that unsigned arithmetic and
two's complement arithmetic are identical with wrapping semantics. This
was changed to use the wrapping_* methods.
Finally, the calculation of variant discriminants could overflow if the
preceeding discriminant was `U64_MAX`. The logic in `rustc::middle::ty`
for this was altered to avoid the overflow completely, while the
remaining places were changed to use wrapping methods. This is because
`rustc::middle::ty::enum_variants` now throws an error when the
calculated discriminant value overflows a `u64`.
This behaviour can be triggered by the following code:
```
enum Foo {
A = U64_MAX,
B
}
```
This commit also implements the remaining integer operators for
Wrapped<T>.
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]
This is a series of individual but correlated changes to the metadata format. The changes are significant enough that it (finally) bumps the metadata encoding version. In brief, they altogether reduce the total size of stage1 binaries by 27% (!!!!). Almost every low-hanging fruit has been considered and fixed; see the individual commits for details.
Detailed library (not just metadata) size changes for x86_64-unknown-linux-gnu stage1 binaries (baseline being 3a96d6a9818fe2affc98a187fb1065120458cee9):
````
before after delta path
--------- --------- ------ --------------------------------
1706146 1050412 38.4% liballoc-4e7c5e5c.rlib
398576 152454 61.8% libarena-4e7c5e5c.rlib
71441 56892 20.4% libarena-4e7c5e5c.so
14424754 5084102 64.8% libcollections-4e7c5e5c.rlib
39143186 14743118 62.3% libcore-4e7c5e5c.rlib
195574 188150 3.8% libflate-4e7c5e5c.rlib
153123 152603 0.3% libflate-4e7c5e5c.so
477152 215262 54.9% libfmt_macros-4e7c5e5c.rlib
77728 66601 14.3% libfmt_macros-4e7c5e5c.so
1216936 684104 43.8% libgetopts-4e7c5e5c.rlib
207846 181116 12.9% libgetopts-4e7c5e5c.so
349722 147530 57.8% libgraphviz-4e7c5e5c.rlib
60196 49197 18.3% libgraphviz-4e7c5e5c.so
729842 259906 64.4% liblibc-4e7c5e5c.rlib
349358 247014 29.3% liblog-4e7c5e5c.rlib
88878 83163 6.4% liblog-4e7c5e5c.so
1968508 732840 62.8% librand-4e7c5e5c.rlib
1968204 696326 64.6% librbml-4e7c5e5c.rlib
283207 206589 27.1% librbml-4e7c5e5c.so
72369394 46401230 35.9% librustc-4e7c5e5c.rlib
11941372 10498483 12.1% librustc-4e7c5e5c.so
2717894 1983272 27.0% librustc_back-4e7c5e5c.rlib
501900 464176 7.5% librustc_back-4e7c5e5c.so
15058 12588 16.4% librustc_bitflags-4e7c5e5c.rlib
4008268 2961912 26.1% librustc_borrowck-4e7c5e5c.rlib
837550 785633 6.2% librustc_borrowck-4e7c5e5c.so
6473348 6095470 5.8% librustc_driver-4e7c5e5c.rlib
1448785 1433945 1.0% librustc_driver-4e7c5e5c.so
95483688 94779704 0.7% librustc_llvm-4e7c5e5c.rlib
43516815 43487809 0.1% librustc_llvm-4e7c5e5c.so
938140 817236 12.9% librustc_privacy-4e7c5e5c.rlib
182653 176563 3.3% librustc_privacy-4e7c5e5c.so
4390288 3543284 19.3% librustc_resolve-4e7c5e5c.rlib
872981 831824 4.7% librustc_resolve-4e7c5e5c.so
18176426 14795426 18.6% librustc_trans-4e7c5e5c.rlib
3657354 3480026 4.8% librustc_trans-4e7c5e5c.so
16815076 13868862 17.5% librustc_typeck-4e7c5e5c.rlib
3274439 3123898 4.6% librustc_typeck-4e7c5e5c.so
21372308 14890582 30.3% librustdoc-4e7c5e5c.rlib
4501971 4172202 7.3% librustdoc-4e7c5e5c.so
8055028 2951044 63.4% libserialize-4e7c5e5c.rlib
958101 710016 25.9% libserialize-4e7c5e5c.so
30810208 15160648 50.8% libstd-4e7c5e5c.rlib
6819003 5967485 12.5% libstd-4e7c5e5c.so
58850950 31949594 45.7% libsyntax-4e7c5e5c.rlib
9060154 7882423 13.0% libsyntax-4e7c5e5c.so
1474310 1062102 28.0% libterm-4e7c5e5c.rlib
345577 323952 6.3% libterm-4e7c5e5c.so
2827854 1643056 41.9% libtest-4e7c5e5c.rlib
517811 452519 12.6% libtest-4e7c5e5c.so
2274106 1761240 22.6% libunicode-4e7c5e5c.rlib
--------- --------- ------ --------------------------------
499359187 363465583 27.2% total
````
Some notes:
* Uncompressed metadata compacts very well. It is less visible for compressed metadata but still it achieves about 5~10% reduction.
* *Every* commit is designed to reduce the metadata in one way. There is absolutely no negative impact associated to changes (that's why the table above doesn't contain a minus delta).
* I've confirmed that this compiles through `make all`, making it almost correct. Other platforms have to be tested though.
* Oh, I'll rebase this as soon as I have spare time, but I guess this needs an extensive review anyway.
* I haven't rigorously checked the encoder and decoder performance. I tried to minimize the impact (some encodings are actually simpler than the original), but I'm not sure.
Fixes#2743, #9303 (partially) and #21482.
This avoids a biggish eight-byte `tag_table_id` tag in favor of
autoserialized integer tags, which are smaller and can be later
used to encode them in the optimal number of bytes. `NodeId` was
u32 after all.
Previously:
<------------- len1 -------------->
tag_table_* <len1> tag_table_id 88 <nodeid in 8 bytes>
tag_table_val <len2> <actual data>
<-- len2 --->
Now:
<--------------- len --------------->
tag_table_* <len> U32 <nodeid in 4 bytes> <actual data>
We try to move the data when the length can be encoded in
the much smaller number of bytes. This interferes with indices and
type abbreviations however, so this commit introduces a public
interface to get and mark a "stable" (i.e. not affected by
relaxation) position of the current pointer.
The relaxation logic only moves a small data, currently at most
256 bytes, as moving the data can be costly. There might be
further opportunities to allow more relaxation by moving fields
around, which I didn't seriously try.
EBML tags are encoded in a variable-length unsigned int (vuint),
which is clever but causes some tags to be encoded in two bytes
while there are really about 180 tags or so. Assuming that there
wouldn't be, say, over 1,000 tags in the future, we can use much
more efficient encoding scheme. The new scheme should support
at most 4,096 tags anyway.
This also flattens a scattered tag namespace (did you know that
0xa9 is followed by 0xb0?) and makes a room for autoserialized tags
in 0x00 through 0x1f.
They are, with a conjunction of `start_tag` and `end_tag`, commonly
used to write a document with a binary data of known size. However
the use of `start_tag` makes the length always 4 bytes long, which
is almost not optimal (requiring the relaxation step to remedy).
Directly using `wr_tagged_*` methods is better for both readability
and resulting metadata size.
* count_ones/zeros, trailing_ones/zeros return u32, not usize
* rotate_left/right take u32, not usize
* RADIX, MANTISSA_DIGITS, DIGITS, BITS, BYTES are u32, not usize
Doesn't touch pow because there's another PR for it.
[breaking-change]
* The lint visitor's visit_ty method did not recurse, and had a
reference to the now closed#10894
* The newly enabled recursion has only affected the `deprectated` lint
which now detects uses of deprecated items in trait impls and
function return types
* Renamed some references to `CowString` and `CowVec` to `Cow<str>` and
`Cow<[T]>`, respectively, which appear outside of the crate which
defines them
* Replaced a few instances of `InvariantType<T>` with
`PhantomData<Cell<T>>`
* Disabled the `deprecated` lint in several places that
reference/implement traits on deprecated items which will get cleaned
up in the future
* Disabled the `exceeding_bitshifts` lint for
compile-fail/huge-array-simple test so it doesn't shadow the expected
error on 32bit systems
* Unfortunately, this means that if a library declares
`#![deny(deprecated)]` and marks anything as deprecated, it will have
to disable the lint for any uses of said item, e.g. any impl the now
deprecated item
For any library that denies deprecated items but has deprecated items
of its own, this is a [breaking-change]
This changes the type of some public constants/statics in libunicode.
Notably some `&'static &'static [(char, char)]` have changed
to `&'static [(char, char)]`. The regexp crate seems to be the
sole user of these, yet this is technically a [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).
Now that the `std::env` module has had some time to bake this commit marks most
of its APIs as `#[stable]`. Some notable APIs that are **not** stable (and still
use the same `env` feature gate) are:
* `{set,get}_exit_status` - there are still questions about whether this is the
right interface for setting/getting the exit status of a process.
* `page_size` - this may change location in the future or perhaps name as well.
This also effectively closes#22122 as the variants of `VarError` are
`#[stable]` now. (this is done intentionally)
This pulls out the implementations of most built-in lints into a
separate crate, to reduce edit-compile-test iteration times with
librustc_lint and increase parallelism. This should enable lints to be
refactored, added and deleted much more easily as it slashes the
edit-compile cycle to get a minimal working compiler to test with (`make
rustc-stage1`) from
librustc -> librustc_typeck -> ... -> librustc_driver ->
libcore -> ... -> libstd
to
librustc_lint -> librustc_driver -> libcore -> ... libstd
which is significantly faster, mainly due to avoiding the librustc build
itself.
The intention would be to move as much as possible of the infrastructure
into the crate too, but the plumbing is deeply intertwined with librustc
itself at the moment. Also, there are lints for which diagnostics are
registered directly in the compiler code, not in their own crate
traversal, and their definitions have to remain in librustc.
This is a [breaking-change] for direct users of the compiler APIs:
callers of `rustc::session::build_session` or
`rustc::session::build_session_` need to manually call
`rustc_lint::register_builtins` on their return value.
This should make #22206 easier.
Now that the `std::env` module has had some time to bake this commit marks most
of its APIs as `#[stable]`. Some notable APIs that are **not** stable (and still
use the same `env` feature gate) are:
* `{set,get}_exit_status` - there are still questions about whether this is the
right interface for setting/getting the exit status of a process.
* `page_size` - this may change location in the future or perhaps name as well.
This also effectively closes#22122 as the variants of `VarError` are
`#[stable]` now. (this is done intentionally)
We were recording stability attributes applied to fields in the
compiler, and even annotating it in the libs, but the compiler didn't
actually do the checks to give errors/warnings in user crates.
This commit moves `std::env` away from the `std::old_io` error type as well as
the `std::old_path` module. Methods returning an error now return `io::Error`
and methods consuming or returning paths use `std::path` instead of
`std::old_path`. This commit does not yet mark these APIs as `#[stable]`.
This commit also migrates `std::old_io::TempDir` to `std::fs::TempDir` with
essentially the exact same API. This type was added to interoperate with the new
path API and has its own `tempdir` feature.
Finally, this commit reverts the deprecation of `std::os` APIs returning the old
path API types. This deprecation can come back once the entire `std::old_path`
module is deprecated.
[breaking-change]
Two changes:
1. Make traits with assoc types invariant w/r/t their inputs.
2. Fully normalize parameter environments, including any region variables (which were being overlooked).
The former supports the latter, but also just seems like a reasonably good idea.
Fixes#21750
cc @edwardw
r? @pnkfelix
This commit moves `std::env` away from the `std::old_io` error type as well as
the `std::old_path` module. Methods returning an error now return `io::Error`
and methods consuming or returning paths use `std::path` instead of
`std::old_path`. This commit does not yet mark these APIs as `#[stable]`.
This commit also migrates `std::old_io::TempDir` to `std::fs::TempDir` with
essentially the exact same API. This type was added to interoperate with the new
path API and has its own `tempdir` feature.
Finally, this commit reverts the deprecation of `std::os` APIs returning the old
path API types. This deprecation can come back once the entire `std::old_path`
module is deprecated.
[breaking-change]
I tried to follow [the style guide][1] as much as possible. This is just from some random readings of the code, so no guarantees on completeness, even in the edited files.
[1]: http://aturon.github.io/style/README.html
