Alex Crichton [Wed, 1 Nov 2017 20:04:03 +0000 (13:04 -0700)]
std: Avoid use of `libc` in portable modules
This commit removes usage of the `libc` crate in "portable" modules like
those at the top level and `sys_common`. Instead common types like `*mut
u8` or `u32` are used instead of `*mut c_void` or `c_int` as well as
switching to platform-specific functions like `sys::strlen` instead of
`libc::strlen`.
Alex Crichton [Wed, 1 Nov 2017 19:59:40 +0000 (12:59 -0700)]
std: Move the `cmath` module into the `sys` module
This commit moves the `f32::cmath` and `f64::cmath` modules into the
`sys` module. Note that these are not publicly exported modules, simply
implementation details. These modules are already platform-specific with
shims on MSVC and this is mostly just a reflection of that reality. This
should also help cut down on `#[cfg]` traffic if platforms are brought on
which don't directly support these functions.
Alex Crichton [Wed, 1 Nov 2017 19:50:13 +0000 (12:50 -0700)]
std: Change how EBADF is handled in `sys`
This commit removes the reexport of `EBADF_ERR` as a constant from
libstd's portability facade, instead opting for a platform-specific
function that specifically queries an `io::Error`. Not all platforms may
have a constant for this, so it makes the intent a little more clear
that a code need not be supplied, just an answer to a query.
Alex Crichton [Wed, 1 Nov 2017 19:32:13 +0000 (12:32 -0700)]
std: Remove `rand` crate and module
This commit removes the `rand` crate from the standard library facade as
well as the `__rand` module in the standard library. Neither of these
were used in any meaningful way in the standard library itself. The only
need for randomness in libstd is to initialize the thread-local keys of
a `HashMap`, and that unconditionally used `OsRng` defined in the
standard library anyway.
The cruft of the `rand` crate and the extra `rand` support in the
standard library makes libstd slightly more difficult to port to new
platforms, namely WebAssembly which doesn't have any randomness at all
(without interfacing with JS). The purpose of this commit is to clarify
and streamline randomness in libstd, focusing on how it's only required
in one location, hashmap seeds.
Note that the `rand` crate out of tree has almost always been a drop-in
replacement for the `rand` crate in-tree, so any usage (accidental or
purposeful) of the crate in-tree should switch to the `rand` crate on
crates.io. This then also has the further benefit of avoiding
duplication (mostly) between the two crates!
bors [Thu, 9 Nov 2017 00:50:56 +0000 (00:50 +0000)]
Auto merge of #45688 - Gankro:layout-tests, r=alexcrichton
Add reftest that checks the layout of repr(int) on non-c-like enums
This verifies the first layout specified in https://github.com/rust-lang/rfcs/pull/2195
The second (`repr(C)`) layout isn't included here because it doesn't actually exist today. However if/when that's implemented a second test could be fairly easily derived from this one.
bors [Wed, 8 Nov 2017 22:27:06 +0000 (22:27 +0000)]
Auto merge of #45867 - michaelwoerister:check-ich-stability, r=nikomatsakis
incr.comp.: Verify stability of incr. comp. hashes and clean up various other things.
The main contribution of this PR is that it adds the `-Z incremental-verify-ich` functionality. Normally, when the red-green tracking system determines that a certain query result has not changed, it does not re-compute the incr. comp. hash (ICH) for that query result because that hash is already known. `-Z incremental-verify-ich` tells the compiler to re-hash the query result and compare the new hash against the cached hash. This is a rather thorough way of
- testing hashing implementation stability,
- finding missing `[input]` annotations on `DepNodes`, and
- finding missing read-edges,
since both a missed read and a missing `[input]` annotation can lead to something being marked as green instead of red and thus will have a different hash than it should have.
Case in point, implementing this verification logic and activating it for all `src/test/incremental` tests has revealed several such oversights, all of which are fixed in this PR.
bors [Wed, 8 Nov 2017 20:00:41 +0000 (20:00 +0000)]
Auto merge of #45452 - estebank:colon-typo, r=nikomatsakis
Detect `=` -> `:` typo in let bindings
When encountering a let binding type error, attempt to parse as
initializer instead. If successful, it is likely just a typo:
```rust
fn main() {
let x: Vec::with_capacity(10);
}
```
```
error: expected type, found `10`
--> file.rs:3:31
|
3 | let x: Vec::with_capacity(10, 20);
| -- ^^
| ||
| |help: did you mean assign here?: `=`
| while parsing the type for `x`
```
bors [Wed, 8 Nov 2017 17:27:56 +0000 (17:27 +0000)]
Auto merge of #45205 - rkruppe:saturating-casts, r=eddyb
Saturating casts between integers and floats
Introduces a new flag, `-Z saturating-float-casts`, which makes code generation for int->float and float->int casts safe (`undef`-free), implementing [the saturating semantics laid out by](https://github.com/rust-lang/rust/issues/10184#issuecomment-299229143) @jorendorff for float->int casts and overflowing to infinity for `u128::MAX` -> `f32`.
Constant evaluation in trans was changed to behave like HIR const eval already did, i.e., saturate for u128->f32 and report an error for problematic float->int casts.
Many thanks to @eddyb, whose APFloat port simplified many parts of this patch, and made HIR constant evaluation recognize dangerous float casts as mentioned above.
Also thanks to @ActuallyaDeviloper whose branchless implementation served as inspiration for this implementation.
bors [Wed, 8 Nov 2017 14:54:03 +0000 (14:54 +0000)]
Auto merge of #45866 - JohnColanduoni:issue-45731, r=alexcrichton
Disable `mmap` in `libbacktrace` on Apple platforms
Fixes #45731
libbacktrace uses mmap if available to map ranges of the files containing debug information. On macOS `mmap` will succeed even if the mapped range does not exist, and a SIGBUS (with an unusual EXC_BAD_ACCESS code 10) will occur when the program attempts to page in the memory. To combat this we force `libbacktrace` to be built with the simple `read` based fallback on Apple platforms.
bors [Wed, 8 Nov 2017 12:23:34 +0000 (12:23 +0000)]
Auto merge of #45575 - michaelwoerister:tweak-inline-trans-items, r=nikomatsakis
Only instantiate inline- and const-fns if they are referenced (again).
It seems that we have regressed on not translating `#[inline]` functions unless they are actually used. This should bring back this optimization. I also added a regression test this time so it doesn't happen again accidentally.
Fixes #40392.
r? @alexcrichton
UPDATE & PSA
---------------------
This patch **makes translation very lazy** -- in general this is a good thing (we don't want the compiler to do unnecessary work) but it has two consequences:
1. Some error messages are only generated when an item is actually translated. Consequently, this patch will lead to more cases where the compiler will only start emitting errors when the erroneous function is actually used. This has always been true to some extend (e.g. when passing generic values to an intrinsic) but since this is something user-facing it's worth mentioning.
2. When writing tests, one has to make sure that the functions in question are actually generated. In other words, it must not be dead code. This can usually be achieved by either
1. making sure the function is exported from the resulting binary or
2. by making sure the function is called from something that is exported (or `main()`).
Note that it depends on the crate type what functions are exported:
1. For rlibs and dylibs everything that is reachable from the outside is exported.
2. For executables, cdylibs, and staticlibs, items are only exported if they are additionally `#[no_mangle]` or have an `#[export_name]`.
The commits in this PR contain many examples of how tests can be updated to comply to the new requirements.
John Colanduoni [Wed, 8 Nov 2017 10:28:17 +0000 (02:28 -0800)]
Disable `mmap` in `libbacktrace` on Apple platforms
Fixes #45731
libbacktrace uses mmap if available to map ranges of the files containing debug information. On macOS `mmap` will succeed even if the mapped range does not exist, and a SIGBUS (with an unusual EXC_BAD_ACCESS code 10) will occur when the program attempts to page in the memory. To combat this we force `libbacktrace` to be built with the simple `read` based fallback on Apple platforms.
Guillaume Gomez [Wed, 8 Nov 2017 09:09:17 +0000 (10:09 +0100)]
Rollup merge of #45830 - pornel:dosglobs, r=dtolnay
Warn about lack of args glob expansion in Windows shell
Because all shells on Linux/macOS expand globs, and even MinGW on Windows emulates this behavior, it's easy to forget that Windows by itself doesn't support glob expansion. This PR documents this cross-platform difference.
bors [Wed, 8 Nov 2017 01:32:12 +0000 (01:32 +0000)]
Auto merge of #45379 - cuviper:unit_from_iter, r=alexcrichton
impl FromIterator<()> for ()
This just collapses all unit items from an iterator into one. This is
more useful when combined with higher-level abstractions, like
collecting to a `Result<(), E>` where you only care about errors:
```rust
use std::io::*;
data = vec![1, 2, 3, 4, 5];
let res: Result<()> = data.iter()
.map(|x| writeln!(stdout(), "{}", x))
.collect();
assert!(res.is_ok());
```
bors [Tue, 7 Nov 2017 20:55:01 +0000 (20:55 +0000)]
Auto merge of #44932 - cuviper:unsized-ptr-is_null, r=alexcrichton
Remove `T: Sized` on pointer `as_ref()` and `as_mut()`
`NonZero::is_zero()` was already casting all pointers to thin `*mut u8` to check for null. The same test on unsized fat pointers can also be used with `as_ref()` and `as_mut()` to get fat references.
(This PR formerly changed `is_null()` too, but checking just the data pointer is not obviously correct for trait objects, especially if `*const self` sorts of methods are ever allowed.)
Robin Kruppe [Mon, 9 Oct 2017 00:14:00 +0000 (02:14 +0200)]
Saturating casts between integers and floats (both directions).
This affects regular code generation as well as constant evaluation in trans,
but not the HIR constant evaluator because that one returns an error for
overflowing casts and NaN-to-int casts. That error is conservatively
correct and we should be careful to not accept more code in constant
expressions.
The changes to code generation are guarded by a new -Z flag, to be able
to evaluate the performance impact. The trans constant evaluation changes
are unconditional because they have no run time impact and don't affect
type checking either.
kennytm [Tue, 7 Nov 2017 07:52:15 +0000 (15:52 +0800)]
Rollup merge of #45784 - harpocrates:fix/print-parens-cast-lt, r=kennytm
Pretty print parens around casts on the LHS of `<`/`<<`
When pretty printing a cast expression occuring on the LHS of a `<` or `<<` expression, we should add parens around the cast. Otherwise, the `<`/`<<` gets interpreted as the beginning of the generics for the type on the RHS of the cast.
Before this PR, the output of the following is not valid Rust:
$ rustc -Z unstable-options --pretty=expanded parens_cast.rs
#![feature(prelude_import)]
#![no_std]
#[prelude_import]
use std::prelude::v1::*;
#[macro_use]
extern crate std as std;
macro_rules! negative(( $ e : expr ) => { $ e < 0 });
fn main() { 1 as i32 < 0; }
After this PR, the output of the following is valid Rust:
$ rustc -Z unstable-options --pretty=expanded parens_cast.rs
#![feature(prelude_import)]
#![no_std]
#[prelude_import]
use std::prelude::v1::*;
#[macro_use]
extern crate std as std;
macro_rules! negative(( $ e : expr ) => { $ e < 0 });
fn main() { (1 as i32) < 0; }
I've gone through several README/wiki style documents but I'm still not sure where to test this though. I'm not even sure if this sort of thing is tested...
kennytm [Tue, 7 Nov 2017 07:52:12 +0000 (15:52 +0800)]
Rollup merge of #45764 - QuietMisdreavus:rustdoc-doctest-lints, r=GuillaumeGomez
rustdoc: add #[allow(unused)] to every doctest
More information in #45750 - this is behavior that was documented but not actually implemented.
I also reordered how outer attributes are applied to doctests. Previously, attributes from `#![doc(test(attr(...)))]` would be applied *after* attributes from within the test itself, meaning if a doctest tried to override lints that would be set crate-wide, it wouldn't work at all. This gives a better scope of how lints can be applied.
kennytm [Tue, 7 Nov 2017 07:52:11 +0000 (15:52 +0800)]
Rollup merge of #45751 - estebank:issue-44684, r=nikomatsakis
Handle anon lifetime arg being returned with named lifetime return type
When there's a lifetime mismatch between an argument with an anonymous
lifetime being returned in a method with a return type that has a named
lifetime, show specialized lifetime error pointing at argument with a
hint to give it an explicit lifetime matching the return type.
```
error[E0621]: explicit lifetime required in the type of `other`
--> file2.rs:21:21
|
17 | fn bar(&self, other: Foo) -> Foo<'a> {
| ----- consider changing the type of `other` to `Foo<'a>`
...
21 | other
| ^^^^^ lifetime `'a` required
```
kennytm [Tue, 7 Nov 2017 07:52:10 +0000 (15:52 +0800)]
Rollup merge of #45682 - RalfJung:rwlock-guards, r=alexcrichton
RwLock guards are Sync if T is
Currently, the compiler requires `T` to also be `Send`. There is no reason for
that. `&Rw{Read,Write}LockGuard` only provides a shared referenced to `T`, sending
that across threads is safe if `T` is `Sync`.
bors [Tue, 7 Nov 2017 14:24:15 +0000 (14:24 +0000)]
Auto merge of #45666 - Amanieu:tls-model, r=alexcrichton
Allow overriding the TLS model
This PR adds the ability to override the default "global-dynamic" TLS model with a more specific one through a target json option or a command-line option. This allows for better code generation in certain situations.
This is similar to the `-ftls-model=` option in GCC and Clang.
bors [Tue, 7 Nov 2017 02:07:34 +0000 (02:07 +0000)]
Auto merge of #45571 - zackmdavis:regenerate_char_private, r=alexcrichton
regenerate libcore/char_private.rs
(filed separately from the work in #45569, because of this matter of the updated Unicode data; see also #45567)
char_private.rs is generated programmatically by char_private.py, using data retrieved from the Unicode Consortium's website.
The motivation here was to make `is_printable` crate-visible (with `pub(crate)`), but it would seem that the Unicode data has changed slightly since char_private.rs was last generated.
bors [Mon, 6 Nov 2017 23:30:57 +0000 (23:30 +0000)]
Auto merge of #45668 - nikomatsakis:nll-free-region, r=arielb1
extend NLL with preliminary support for free regions on functions
This PR extends https://github.com/rust-lang/rust/pull/45538 with support for free regions. This is pretty preliminary and will no doubt want to change in various ways, particularly as we add support for closures, but it's enough to get the basic idea in place:
- We now create specific regions to represent each named lifetime declared on the function.
- Region values can contain references to these regions (represented for now as a `BTreeSet<RegionIndex>`).
- If we wind up trying to infer that `'a: 'b` must hold, but no such relationship was declared, we report an error.
bors [Mon, 6 Nov 2017 20:43:46 +0000 (20:43 +0000)]
Auto merge of #45811 - DSpeckhals:update-rustfmt-rls, r=nikomatsakis
tools: Fix rustfmt and the RLS
These tools have been corrected in their upstream repo's, and the submodules have been updated here to reflect that. I also had to update Cargo to match what the RLS is expecting.
The tool states for `rustfmt` and `rls` where both changed from "Broken" to "Testing" in this commit, thus enabling testing and distribution again.
bors [Mon, 6 Nov 2017 18:04:13 +0000 (18:04 +0000)]
Auto merge of #45322 - infinity0:master, r=alexcrichton
When cross-compiling, also build target-arch tarballs for libstd. (Closes: #42320)
Half of the logic is actually in there already in install.rs:install_std but it fails with an error like:
sh: 0: Can't open /<<BUILDDIR>>/rustc-1.21.0+dfsg1/build/tmp/dist/rust-std-1.21.0-powerpc64le-unknown-linux-gnu/install.sh
because the target-arch dist tarball wasn't built as well. This commit fixes that so the overall install works.
There is one minor bug in the existing code which this commit doesn't fix - the install.log from multiple runs of the installer gets clobbered, which seems like it might interfere with the uninstall process (I didn't look very deeply into this, because it doesn't affect what I need to do.) The actual installed files under DESTDIR seem fine though - either they are installed under an arch-specific path, or the multiple runs will clobber the same path with the same arch-independent file.
These tools have been corrected in their upstream repo's, and the
submodules have been updated here to reflect that. I also had to update
Cargo to match what the RLS is expecting.
The tool states for `rustfmt` and `rls` where both changed from "Broken"
to "Testing" in this commit, thus enabling testing and distribution
again.
bors [Mon, 6 Nov 2017 15:19:48 +0000 (15:19 +0000)]
Auto merge of #45369 - fintelia:patch-1, r=BurntSushi
Implement is_empty() for BufReader
Simple implementation of `is_empty` method for BufReader so it is possible to tell whether there is any data in its buffer.
I didn't know correct stability annotation to place on the function. Presumably there is no reason to place this feature behind a feature flag, but I wasn't sure how to tag it as an unstable feature without that.
bors [Sun, 5 Nov 2017 22:06:15 +0000 (22:06 +0000)]
Auto merge of #45770 - spastorino:newtype_index, r=nikomatsakis
Make last structs indexes definitions use newtype_index macro
This PR makes the last two index structs not using newtype_index macro to use it and also fixes this https://github.com/rust-lang/rust/issues/45763 issue.
bors [Sun, 5 Nov 2017 19:19:59 +0000 (19:19 +0000)]
Auto merge of #45723 - sinkuu:ice_45493, r=arielb1
Fix MIR inlining panic in generic function
MIR inlining calls `Instance::resolve` with a substs containing param, and `trans_apply_param_substs` panics. ~~This PR fixes it by making `Instance::resolve` return `None` if `substs.has_param_types()`, though I'm not sure if this is a right fix.~~
Esteban Küber [Sat, 4 Nov 2017 00:30:14 +0000 (17:30 -0700)]
Handle anon lifetime arg being returned with named lifetime return type
When there's a lifetime mismatch between an argument with an anonymous
lifetime being returned in a method with a return type that has a named
lifetime, show specialized lifetime error pointing at argument with a
hint to give it an explicit lifetime matching the return type.
```
error[E0621]: explicit lifetime required in the type of `other`
--> file2.rs:21:21
|
17 | fn bar(&self, other: Foo) -> Foo<'a> {
| ----- consider changing the type of `other` to `Foo<'a>`
...
21 | other
| ^^^^^ lifetime `'a` required
```
Alec Theriault [Sun, 5 Nov 2017 17:28:00 +0000 (09:28 -0800)]
Pretty print parens around casts on the LHS of '<'
When pretty printing a cast expression occuring on the LHS of a '<'
or '<<' expression, we should add parens around the cast. Otherwise,
the '<'/'<<' gets interpreted as the beginning of the generics for
the type on the RHS of the cast.
bors [Sun, 5 Nov 2017 16:49:08 +0000 (16:49 +0000)]
Auto merge of #45072 - nikomatsakis:issue-38714, r=arielb1
new rules for merging expected and supplied types in closure signatures
As uncovered in #38714, we currently have some pretty bogus code for combining the "expected signature" of a closure with the "supplied signature". To set the scene, consider a case like this:
```rust
fn foo<F>(f: F)
where
F: for<'a> FnOnce(&'a u32) -> &'a u32
// ^ *expected* signature comes from this where-clause
{
...
}
fn main() {
foo(|x: &u32| -> &u32 { .. }
// ^^^^^^^^^^^^^^^^^ supplied signature
// comes from here
}
```
In this case, the supplied signature (a) includes all the parts and (b) is the same as the expected signature, modulo the names used for the regions. But often people supply only *some* parts of the signature. For example, one might write `foo(|x| ..)`, leaving *everything* to be inferred, or perhaps `foo(|x: &u32| ...)`, which leaves the return type to be inferred.
In the current code, we use the expected type to supply the types that are not given, but otherwise use the type the user gave, except for one case: if the user writes `fn foo(|x: _| ..)` (i.e., an underscore at the outermost level), then we will take the expected type (rather than instantiating a fresh type variable). This can result in nonsensical situations, particularly with bound regions that link the types of parameters to one another or to the return type. Consider `foo(|x: &u32| ...)` -- if we *literally* splice the expected return type of `&'a u32` together with what the user gave, we wind up with a signature like `for<'a> fn(&u32) -> &'a u32`. This is not even permitted as a type, because bound regions like `'a` must appear also in the arguments somewhere, which is why #38714 leads to an ICE.
This PR institutes some new rules. These are not meant to be the *final* set of rules, but they are a kind of "lower bar" for what kind of code we accept (i.e., we can extend these rules in the future to be smarter in some cases, but -- as we will see -- these rules do accept some things that we then would not be able to back off from).
These rules are derived from a few premises:
- First and foremost, anonymous regions in closure annotation are mostly requests for the code to "figure out the right lifetime" and shouldn't be read too closely. So for example when people write a closure signature like `|x: &u32|`, they are really intended for us to "figure out" the right region for `x`.
- In contrast, the current code treats this supplied type as being more definitive. In particular, writing `|x: &u32|` would always result in the region of `x` being bound in the closure type. In other words, the signature would be something like `for<'a> fn(&'a u32)` -- this is derived from the fact that `fn(&u32)` expands to a type where the region is bound in the fn type.
- This PR takes a different approach. The "binding level" for reference types appearing in closure signatures can be informed in some cases by the expected signature. So, for example, if the expected signature is something like `(&'f u32)`, where the region of the first argument appears free, then for `|x: &u32|`, the new code would infer `x` to also have the free region `'f`.
- This inference has some limits. We don't do this for bindings that appear within the selected types themselves. So e.g. `|x: fn(&u32)|`, when combined with an expected type of `fn(fn(&'f u32))`, would still result in a closure that expects `for<'a> fn(&'a u32)`. Such an annotation will ultimately result in an error, as it happens, since `foo` is supplying a `fn(&'f u32)` to the closure, but the closure signature demands a `for<'a> fn(&'a u32)`. But still we choose to trust it and have the user change it.
- I wanted to preserve the rough intuition that one can copy-and-paste a type out of the fn signature and into the fn body without dramatically changing its meaning. Interestingly, if one has `|x: &u32|`, then regardless of whether the region of `x` is bound or free in the closure signature, it is also free in the region body, and that is also true when one writes `let x: &u32`, so that intuition holds here. But the same would not be true for `fn(&u32)`, hence the different behavior.
- Second, we must take either **all** the references to bound regions from the expected type or **none**. The current code, as we saw, will happily take a bound region in the return type but drop the other place where it is used, in the parameters. Since bound regions are all about linking multiple things together, I think it's important not to do that. (That said, we could conceivably be a bit less strict here, since the subtyping rules will get our back, but we definitely don't want any bound regions that appear only in the return type.)
- Finally, we cannot take the bound region names from the supplied types and "intermix" them with the names from the expected types.
- We *could* potentially do some alpha renaming, but I didn't do that.
- Ultimately, if the types the user supplied do not match expectations in some way that we cannot recover from, we fallback to deriving the closure signature solely from those expected types.
- For example, if the expected type is `u32` but the user wrote `i32`.
- Or, more subtle, if the user wrote e.g. `&'x u32` for some named lifetime `'x`, but the expected type includes a bound lifetime (`for<'a> (&'a u32)`). In that case, preferring the type that the user explicitly wrote would hide an appearance of a bound name from the expected type, and we try to never do that.
The detailed rules that I came up with are found in the code, but for ease of reading I've also [excerpted them into a gist](https://gist.github.com/nikomatsakis/e69252a2b57e6d97d044c2f254c177f1). I am not convinced they are correct and would welcome feedback for alternative approaches.
(As an aside, the way I think I would ultimately *prefer* to think about this is that the conversion from HIR types to internal types could be parameterized by an "expected type" that it uses to guide itself. However, since that would be a pain, I opted *in the code* to first instantiate the supplied types as `Ty<'tcx>` and then "merge" those types with the `Ty<'tcx>` from the expected signature.)
I think we should probably FCP this before landing.