Travis CI has new infrastructure using the Google Compute Engine which has both
faster CPUs and more memory, and we've been encouraged to switch as it should
help our build times! The only downside currently, however, is that IPv6 is
disabled, causing a number of standard library tests to fail.
Consequently this commit tweaks our travis config in a few ways:
* ccache is disabled as it's not working on GCE just yet
* Docker is used to run tests inside which reportedly will get IPv6 working
* A system LLVM installation is used instead of building LLVM itself. This is
primarily done to reduce build times, but we want automation for this sort of
behavior anyway and we can extend this in the future with building from source
as well if needed.
* gcc-specific logic is removed as the docker image for Ubuntu gives us a
recent-enough gcc by default.
- Expand the first paragraph
- Improve readability by partitioning the chapter into the following
sections: "Patterns", "Type annotations", "Mutability", and
"Initializing bindings"
- Add "Scope and shadowing" section (fix#28177)
Travis CI has new infrastructure using the Google Compute Engine which has both
faster CPUs and more memory, and we've been encouraged to switch as it should
help our build times! The only downside currently, however, is that IPv6 is
disabled, causing a number of standard library tests to fail.
Consequently this commit tweaks our travis config in a few ways:
* ccache is disabled as it's not working on GCE just yet
* Docker is used to run tests inside which reportedly will get IPv6 working
* A system LLVM installation is used instead of building LLVM itself. This is
primarily done to reduce build times, but we want automation for this sort of
behavior anyway and we can extend this in the future with building from source
as well if needed.
* gcc-specific logic is removed as the docker image for Ubuntu gives us a
recent-enough gcc by default.
This prevents ICEs when old crates are used with a new version of
rustc. Currently, the linking of crates compiled with different
versions of rustc is completely unsupported.
Fixes#28700
r? @nrc
Some minor parts of AST and HIR were not visited by the `visit::walk_xxx` methods - some identifiers, lifetimes, loop labels, attributes of exported macros - but nothing as serious as in, for example, https://github.com/rust-lang/rust/pull/28364.
\+ Added a convenience macro for visiting lists (including Options)
\+ Removed some pre-Deref-coersions `&**` noise from visitors
r? @nrc
I just removed the num_cpus dependency (because we don't want that in there), using 4 threads instead.
I should add that Veedrac asked me to submit this here in his name.
This prevents ICEs when old crates are used with a new version of
rustc. Currently, the linking of crates compiled with different
versions of rustc is completely unsupported.
Fixes#28700
Especially when documenting the use of `0`, since zero looks very
similar to `O` in fonts not meant for displaying code.
Other literal characters, traits, etc should also use code formatting.
This change makes this documentation more internally consistent.
Before this change, circled is the character I was using this documentation to find out about and that confused me when it wasn't immediately clear what character it was:
<img width="1013" alt="screen shot 2015-09-28 at 10 13 31 pm" src="https://cloud.githubusercontent.com/assets/193874/10154708/c70815fe-6638-11e5-9acc-57c73a524203.png">
After this change:
<img width="981" alt="screen shot 2015-09-28 at 11 26 35 pm" src="https://cloud.githubusercontent.com/assets/193874/10154710/ce73eeb2-6638-11e5-98f7-902f58679316.png">
I ran `make check-docs` and didn't break anything ⭐
Especially when documenting the use of `0`, since zero looks very
similar to `O` in fonts not meant for displaying code.
Other literal characters, traits, etc should also use code formatting.
This change makes this documentation more internally consistent.
This commit updates the compiler to not attempt to use jemalloc for platforms
where jemalloc is never enabled. Currently the compiler attempts to link in
jemalloc based on whether `--disable-jemalloc` was specified at build time for
the compiler itself, but this is only the right decision for the host target,
not for other targets.
This still leaves a hole open where a set of target libraries are downloaded
which were built with `--disable-jemalloc` and the compiler is unaware of that,
but this is a pretty rare case so it can always be fixed later.
By putting an "unreachable" instruction into the default arm of a switch
instruction we can let LLVM know that the match is exhaustive, allowing
for better optimizations.
For example, this match:
```rust
pub enum Enum {
One,
Two,
Three,
}
impl Enum {
pub fn get_disc(self) -> u8 {
match self {
Enum::One => 0,
Enum::Two => 1,
Enum::Three => 2,
}
}
}
```
Currently compiles to this on x86_64:
```asm
.cfi_startproc
movzbl %dil, %ecx
cmpl $1, %ecx
setne %al
testb %cl, %cl
je .LBB0_2
incb %al
movb %al, %dil
.LBB0_2:
movb %dil, %al
retq
.Lfunc_end0:
```
But with this change we get:
```asm
.cfi_startproc
movb %dil, %al
retq
.Lfunc_end0:
```
This was non-obvious to me: with no example, I assumed `Electron {}` and
didn't know what else to try when it didn't work. The correct form is
weird because it looks like you're assigning the struct name rather than
an instance of the struct.
r? @steveklabnik
the example for `find` was misleading in that it fails to mention the result is either `None` or `Some` containing only the first match. Further confusing the issue is the `println!` statement, "We got some numbers!"
