Currently the compiler has no knowledge of `#[thread_local]` which forces users
to take on two burdens of unsafety:
* The lifetime of the borrow of a `#[thread_local]` static is **not** `'static`
* Types in `static`s are required to be `Sync`
The thread-local modules mostly curb these facets of unsafety by only allowing
very limited scopes of borrows as well as allowing all types to be stored in a
thread-local key (regardless of whether they are `Sync`) through an `unsafe
impl`.
Unfortunately these measures have the consequence of being able to take the
address of the key itself and send it to another thread, allowing the same key
to be accessed from two different threads. This is clearly unsafe, and this
commit fixes this problem with the same trick used by `LocalKey`, which is to
have an indirect function call to find the address of the *current thread's*
thread local. This way the address of thread local keys can safely be sent among
threads as their lifetime truly is `'static`.
This commit will reduce the performance of cross-crate scoped thread locals as
it now requires an indirect function call, but this can likely be overcome in a
future commit.
Closes#25894
The "unit value" is a value of the "unit type," not the "unit value type." Regardless of correctness, this straight syntax is easier to grok.
Part of #16676
Sorry if something's off here, it's my first pull request to rust!
Because these structures are created by a macro, the doc comments
don't quite work: the leading /// isn't stripped. Instead, just
use #[doc] so that they render correctly.
Use result of the computation to prevent the compiler from optimising
too much. Change `_x` to `x` and therefore remove the paragraph about
the underscore.
Fixes#25855.
r? @steveklabnik
In https://github.com/rust-lang/rust/pull/23289, I did not include the type information for searching for orphan methods (methods that are defined in a module and implemented in another - doing this causes rustdoc sometimes to first find the impl before the actual type).
This PR fixes this. By merging this, searches for `char -> bool` will also find `is_alphabetic`, for example (which otherwise was only found for `charext -> bool`).
cc @alexcrichton
Use result of the computation to prevent the compiler from optimising
too much. Change `_x` to `x` and therefore remove the paragraph about
the underscore.
Fixes#25855.
Because these structures are created by a macro, the doc comments
don't quite work: the leading /// isn't stripped. Instead, just
use #[doc] so that they render correctly.
musl may not be available on the target user's machine, and even if it is, we may not be able to find it because of how static libraries are searched for.
Instead, use the liblibc archive created at rust compile time which already contains libc.a.
---
To be honest, my brain is bending a bit at this point and I wonder if I'm doing something a bit stupid.
Problem: building the libc crate with target musl. It says "could not find native static library `c`, perhaps an -L flag is missing?".
Some pondering: the key problem is the way static archives are searched for (note that a musl build attempts to statically link to libc) - they aren't. There are three locations which are checked (including `$PREFIX/lib/rustlib/x86_64-unknown-linux-musl/lib`), but this does not include `$PREFIX/lib`...and it probably shouldn't - rustc is mimicking the way native lib generation works by forcing you to provide the path yourself. You can make it work `cargo rustc` with `-L native=/path/to/musl/lib`, but even if this went in a build script for the libc crate, it wouldn't work if musl isn't installed by the end user.
I've sprinkled `not(test)` around but I've no idea if I've done it right.
This patch allows `cargo build --target x86_64-unknown-linux-musl` to work on a crate with a dependency on libc, where the musl-enabled rust was compiled before this patch. I've not yet kicked off the long process to build a musl-enabled rust with this patch, so it might be broken there.
Sorry for the rambling.
r? @alexcrichton
musl may not be available on the target user's machine, and even if
it is, we may not be able to find it because of how static libraries
are searched for.
Instead, use the transitively included liblibc which includes libc.a.
Closes#25977
The various `stdfoo_raw` methods in std::io now return `io::Result`s,
since they may not exist on Windows. They will always return `Ok` on
Unix-like platforms.
[breaking-change]
As it says in the title. I've added an `expect` method to `Result` that allows printing both an error message (e.g. what operation was attempted), and the error value. This is separate from the `unwrap` and `ok().expect("message")` behaviours.
Closes#25977
The various `stdfoo_raw` methods in std::io now return `io::Result`s,
since they may not exist on Windows. They will always return `Ok` on
Unix-like platforms.
[breaking-change]
The plugin that enforces error explanation line-length is a bit restrictive, particularly when attempting to use URLs in explanations (cf #26163).
Jashank will still have to do some mucking around with `#[cfg(not(stage0))]` attributes or else wait until a snapshot with this commit lands.
don't try to bind __morestack symbol under OpenBSD as the platform don't
have morestack support.
r? @alexcrichton
it unbreak build under OpenBSD. Does some others platforms don't have morestack too ? They should be impacted by this problem too.
`assert_eq!` has better diagnostics than `assert!` and is more helpful when something actually breaks, but the diagnostics has it's price - `assert_eq!` generate some formatting code which is slower to compile and possibly run.
[My measurements](https://internals.rust-lang.org/t/assert-a-b-or-assert-eq-a-b/1367/12?u=petrochenkov) show that presence of this formatting code doesn't affect compilation + execution time of the test suite significantly, so `assert_eq!` can be used instead of `assert!` consistently.
(Some tests doesn't reside in src/test, they are not affected by these changes, I'll probably open a separate PR for them later)
musl only creates rlib files for stdlib linking so we need to ignore the `CFG_LIB_GLOB_` setting, otherwise we an error:
```
$ make --debug VERBOSE=1 dist-tar-bins
[...]
Successfully remade target file `prepare-target-x86_64-unknown-linux-gnu-host-x86_64-unknown-linux-gnu-2-dir-x86_64-unknown-linux-gnu'.
File `prepare-target-x86_64-unknown-linux-musl-host-x86_64-unknown-linux-gnu-2-dir-x86_64-unknown-linux-gnu' does not exist.
Must remake target `prepare-target-x86_64-unknown-linux-musl-host-x86_64-unknown-linux-gnu-2-dir-x86_64-unknown-linux-gnu'.
umask 022 && mkdir -p tmp/dist/rustc-1.2.0-dev-x86_64-unknown-linux-gnu-image/lib/rustlib/x86_64-unknown-linux-musl/lib
umask 022 && mkdir -p tmp/dist/rustc-1.2.0-dev-x86_64-unknown-linux-gnu-image/lib/rustlib/x86_64-unknown-linux-gnu/bin
LIB_NAME="liblibc-d8ace771.rlib"; MATCHES=""; if [ -n "$MATCHES" ]; then echo "warning: one or libraries matching Rust library 'liblibc-*.rlib'" && echo " (other than '$LIB_NAME' itself) alre
ady present" && echo " at destination tmp/dist/rustc-1.2.0-dev-x86_64-unknown-linux-gnu-image/lib/rustlib/x86_64-unknown-linux-musl/lib:" && echo $MATCHES ; fi
install -m644 `ls -drt1 x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-musl/lib/liblibc-*.rlib` tmp/dist/rustc-1.2.0-dev-x86_64-unknown-linux-gnu-image/lib/rustlib/x86_64-unk
nown-linux-musl/lib/
LIB_NAME=""; MATCHES=""; if [ -n "$MATCHES" ]; then echo "warning: one or libraries matching Rust library 'libstd-*.so'" && echo " (other than '$LIB_NAME' itself) already present" && echo
" at destination tmp/dist/rustc-1.2.0-dev-x86_64-unknown-linux-gnu-image/lib/rustlib/x86_64-unknown-linux-musl/lib:" && echo $MATCHES ; fi
install -m644 `ls -drt1 x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-musl/lib/libstd-*.so` tmp/dist/rustc-1.2.0-dev-x86_64-unknown-linux-gnu-image/lib/rustlib/x86_64-unknow
n-linux-musl/lib/
ls: cannot access x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-musl/lib/libstd-*.so: No such file or directory
install: missing destination file operand after ‘tmp/dist/rustc-1.2.0-dev-x86_64-unknown-linux-gnu-image/lib/rustlib/x86_64-unknown-linux-musl/lib/’
Try 'install --help' for more information.
make: *** [prepare-target-x86_64-unknown-linux-musl-host-x86_64-unknown-linux-gnu-2-dir-x86_64-unknown-linux-gnu] Error 1
```
`CFG_INSTALL_ONLY_RLIB_` is provided for this reason and fixes `make install` and `make dist`.
mk: Build crates with relative source file paths
The path we pass to rustc will be visible in panic messages and
backtraces: they will be user visible!
Avoid junk in these paths by passing relative paths to rustc.
For most advanced users, `libcore` or `libstd` in the path will be
a clue to the location -- inside our code, not theirs.
Store both the relative path to the source as well as the absolute.
Use the relative path where it matters, compiling the main crates,
instead of changing all of the build process to cope with relative
paths.
Example output after this patch:
```
$ ./testunwrap
thread '<main>' panicked at 'called `Option::unwrap()` on a `None` value', ../src/libcore/option.rs:362
$ RUST_BACKTRACE=1 ./testunwrap
thread '<main>' panicked at 'called `Option::unwrap()` on a `None` value', ../src/libcore/option.rs:362
stack backtrace:
1: 0x7ff59c1e9956 - sys::backtrace::write::h67a542fd2b201576des
at ../src/libstd/sys/unix/backtrace.rs:158
2: 0x7ff59c1ed5b6 - panicking::on_panic::h3d21c41cdd5c12d41Xw
at ../src/libstd/panicking.rs:58
3: 0x7ff59c1e7b6e - rt::unwind::begin_unwind_inner::h9f3a5440cebb8baeLDw
at ../src/libstd/rt/unwind/mod.rs:273
4: 0x7ff59c1e7f84 - rt::unwind::begin_unwind_fmt::h4fe8a903e0c296b0RCw
at ../src/libstd/rt/unwind/mod.rs:212
5: 0x7ff59c1eced7 - rust_begin_unwind
6: 0x7ff59c22c11a - panicking::panic_fmt::h00b0cd49c98a9220i5B
at ../src/libcore/panicking.rs:64
7: 0x7ff59c22b9e0 - panicking::panic::hf549420c0ee03339P3B
at ../src/libcore/panicking.rs:45
8: 0x7ff59c1e621d - option::Option<T>::unwrap::h501963526474862829
9: 0x7ff59c1e61b1 - main::hb5c91ce92347d1e6eaa
10: 0x7ff59c1f1c18 - rust_try_inner
11: 0x7ff59c1f1c05 - rust_try
12: 0x7ff59c1ef374 - rt::lang_start::h7e51e19c6677cffe5Sw
at ../src/libstd/rt/unwind/mod.rs:147
at ../src/libstd/rt/unwind/mod.rs:130
at ../src/libstd/rt/mod.rs:128
13: 0x7ff59c1e628e - main
14: 0x7ff59b3f6b44 - __libc_start_main
15: 0x7ff59c1e6078 - <unknown>
16: 0x0 - <unknown>
```
instead of enumerate the (long) list of platforms to exclude, use only
the short list of platforms to include.
should fixes __morestack symbol problem under openbsd
This test has an interesting history, because of fail -> panic. It was
originally called extern-fail.rs:
https://github.com/rust-lang/rust/commits/master/src/test/run-fail/extern-fail.rs
It lived for a while, but was disabled in August 2013:
ce95b01014
As you can see, that failure was not specific to this test, however,
this code does stuff with the runtime, which was removed. Given that
it hasn't even been able to compile in a long time, we should just
remove it.
r? @brson
