Allow rustc data structures compile to android
flock structure is defined in asm*/fcntl.h. This file on android is
generated from the linux kernel source, so they are the same.
Explicitly mention that `Vec::reserve` is based on len not capacity
I spent a good chunk of time tracking down a buffer overrun bug that
resulted from me mistakenly thinking that `reserve` was based on the
current capacity not the current length. It would be helpful if this
were called out explicitly in the docs.
remove wrong packed struct test
This UB was found by running the test under [Miri](https://github.com/solson/miri) which rejects these unsafe unaligned loads. 😄
Actually fix manifest generation
The previous fix contained an error where `toml::encode` returned a runtime
error, so this version just constructs a literal `toml::Value`.
Don't include directory names in shasums
Right now we just run `shasum` on an absolute path but right now the shasum
files only include filenames, so let's use `current_dir` and just the file name
to only have the file name emitted.
Fix a misleading statement in `Iterator.nth()`
The `Iterator.nth()` documentation says "Note that all preceding elements will be consumed". I assumed from that that the preceding elements would be the *only* ones that were consumed, but in fact the returned element is consumed as well.
The way I read the documentation, I assumed that `nth(0)` would not discard anything (there are 0 preceding elements, and maybe it just peeks at the start of the iterator somehow), so I added a sentence clarifying that it does. I also rephrased it to avoid the stunted "i.e." phrasing.
Specialize `PartialOrd<A> for [A] where A: Ord`
This way we can call `cmp` instead of `partial_cmp` in the loop, removing some burden of optimizing `Option`s away from the compiler.
PR #39538 introduced a regression where sorting slices suddenly became slower, since `slice1.lt(slice2)` was much slower than `slice1.cmp(slice2) == Less`. This problem is now fixed.
To verify, I benchmarked this simple program:
```rust
fn main() {
let mut v = (0..2_000_000).map(|x| x * x * x * 18913515181).map(|x| vec![x, x ^ 3137831591]).collect::<Vec<_>>();
v.sort();
}
```
Before this PR, it would take 0.95 sec, and now it takes 0.58 sec.
I also tried changing the `is_less` lambda to use `cmp` and `partial_cmp`. Now all three versions (`lt`, `cmp`, `partial_cmp`) are equally performant for sorting slices - all of them take 0.58 sec on the
benchmark.
Tangentially, as soon as we get `default impl`, it might be a good idea to implement a blanket default impl for `lt`, `gt`, `le`, `ge` in terms of `cmp` whenever possible. Today, those four functions by default are only implemented in terms of `partial_cmp`.
r? @alexcrichton
Add Emscripten-specific linker
Emscripten claims to accept most GNU linker options, but in fact most of `-Wl,...` are useless for it and instead it requires some additional special options which are easier to handle in a separate trait.
Currently added:
- `export_symbols`: works on executables as special Emscripten case since staticlibs/dylibs aren't compiled to JS, while exports are required to be accessible from JS.
Fixes#39171.
- `optimize` - translates Rust's optimization level to Emscripten optimization level (whether passed via `-C opt-level=...` or `-O...`).
Fixes#36899.
- `debuginfo` - translates debug info; Emscripten has 5 debug levels while Rust has 3, so chose to translate `-C debuginfo=1` to `-g3` (preserves whitespace, variable and function names for easy debugging).
Fixes#36901.
- `no_default_libraries` - tells Emscripten to exclude `memcpy` and co.
TODO (in future PR): dynamic linking via `SIDE_MODULE` / `MAIN_MODULE` mechanism.
Conversions between slices and boxes
This allows conversion for `Copy` slices, `str`, and `CStr` into their boxed counterparts.
This also adds the method `CString::into_boxed_c_str`.
I would like to add similar implementations for `OsStr` as well, but I have not figured out how.
It claims to accept most GNU linker options, but in fact most of them
have no effect and instead it requires some special options which are
easier to handle in a separate trait.
Currently added:
- `export_symbols`: works on executables as special Emscripten case
since staticlibs/dylibs aren't compiled to JS, while exports are
required to be accessible from JS.
Fixes#39171.
- `optimize` - translates Rust's optimization level to Emscripten
optimization level (whether passed via `-C opt-level=...` or `-O...`).
Fixes#36899.
- `debuginfo` - translates debug info; Emscripten has 5 debug levels
while Rust has 3, so chose to translate `-C debuginfo=1` to `-g3`
(preserves whitespace, variable and function names for easy debugging).
Fixes#36901.
- `no_default_libraries` - tells Emscripten to exlude `memcpy` and co.
The `Iterator.nth()` documentation says "Note that all preceding elements will be consumed". I assumed from that that the preceding elements would be the *only* ones that were consumed, but in fact the returned element is consumed as well.
The way I read the documentation, I assumed that `nth(0)` would not discard anything (as there are 0 preceding elements), so I added a sentence clarifying that it does. I also rephrased it to avoid the stunted "i.e." phrasing.
name anonymous fn parameters in libcore traits
This follows the discussion in rust-lang/rfcs#1685. The patch gives names to anonymous parameters in libcore traits. It would have two benefits I can think of: firstly it would provide names to tools that can use the names from the traits, and secondly core/std can serve as an example when writing traits; this change helps by not encouraging the use of anonymous parameters.
rustbuild: support setting verbosity in config.toml
Most if not all the configuration is settable trhough config.toml but the verbosity isn't yet.
This avoids having to pass -v to x.py on each command if you want verbosity to be always on.
I spent a good chunk of time tracking down a buffer overrun bug that
resulted from me mistakenly thinking that `reserve` was based on the
current capacity not the current length. It would be helpful if this
were called out explicitly in the docs.
Fix unsafe unaligned loads in test.
r? @eddyb
cc @Aatch @nikomatsakis
The `#[derive(PartialEq, Debug)]` impls on a packed struct contain undefined behaviour. Both generated impls take references to unaligned fields, which will fail to compile once we correctly treat that as unsafe (see https://github.com/rust-lang/rust/issues/27060).
This UB was found by running the test under [Miri](https://github.com/solson/miri/) which rejects these unsafe unaligned loads. 😄
Here's a simpler example:
```rust
struct Packed {
a: u8,
b: u64,
}
```
It expands to:
```rust
fn fmt(&self, __arg_0: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
match *self {
Packed { a: ref __self_0_0, b: ref __self_0_1 } => { // BAD: these patterns are unsafe
let mut builder = __arg_0.debug_struct("Packed");
let _ = builder.field("a", &&(*__self_0_0));
let _ = builder.field("b", &&(*__self_0_1));
builder.finish()
}
}
}
```
and
```rust
fn eq(&self, __arg_0: &Packed) -> bool {
match *__arg_0 {
Packed { a: ref __self_1_0, b: ref __self_1_1 } => // BAD: these patterns are unsafe
match *self {
Packed { a: ref __self_0_0, b: ref __self_0_1 } => // BAD: these patterns are unsafe
true && (*__self_0_0) == (*__self_1_0) &&
(*__self_0_1) == (*__self_1_1),
},
}
}
```
Exclude top-level macro expansions from source location override.
It occurred to me that a simple heuristic can address the issue #36382: any macros that expand into items (including `include!()`) don't need to be stepped over because there's not code to step through above a function scope level.
r? @michaelwoerister
Choose different name for metadata obj-file to avoid clashes with user-chosen names.
Fixes#39585 and probably https://github.com/rust-lang/rust/issues/39508.
Incremental compilation assigns different names to obj-files than regular compilation. If a crate is called "metadata" this can lead to a clash between the root module's obj-file and the obj-file containing crate-metadata. This PR assigns a name to the metadata obj-file that cannot clash with other obj-file because it contains a `.` which is not allowed in a Rust module identifier.
r? @alexcrichton
cc @nikomatsakis
Emit DW_AT_main_subprogram
This changes rustc to emit DW_AT_main_subprogram on the "main" program.
This lets gdb suitably stop at the user's main in response to
"start" (rather than the library's main, which is what happens
currently).
Fixes#32620
r? michaelwoerister
