Refine lifetimes in signature for graph node/edge iteration methods.
Added `pub` `node_id` and `edge_id` methods that correspond to
NodeIndex and EdgeIndex `get` methods (note that the inner index is
already `pub` in the struct definitions). (I decided that `get()`,
used internally, just looks too generic and that client code is
clearer with more explicit method names.)
Add `EntryPat` and `NodePat` variants to ast_map, so that lookups for
id 1 in `let S{val: _x /* pat 2 */} /* pat 1 */ = ...` will actually
resolve to the pattern `S{ ... }`, rather than "unknown node", in a
function like `node_id_to_str`.
The core library in theory has 0 dependencies, but in practice it has some in
order for it to be efficient. These dependencies are in the form of the basic
memory operations provided by libc traditionally, such as memset, memcmp, etc.
These functions are trivial to implement and themselves have 0 dependencies.
This commit adds a new crate, librlibc, which will serve the purpose of
providing these dependencies. The crate is never linked to by default, but is
available to be linked to by downstream consumers. Normally these functions are
provided by the system libc, but in other freestanding contexts a libc may not
be available. In these cases, librlibc will suffice for enabling execution with
libcore.
cc #10116
pthread_yield is non-standard, while sched_yield is POSIX
The Linux documentation recommends using the standard function. This is
the only feature we're currently using that's present in glibc but not
in musl.
Previously, the `from_bits` function in the `std::bitflags::bitflags`
macro was marked as unsafe, as it did not check that the bits being
converted actually corresponded to flags.
This patch changes the function to check against the full set of
possible flags and return an `Option` which is `None` if a non-flag bit
is set. It also adds a `from_bits_truncate` function which simply zeros
any bits not corresponding to a flag.
This addresses the concern raised in https://github.com/mozilla/rust/pull/13897
After discussion with Alex, we think the proper policy is for dtors
to not fail. This is consistent with C++. BufferedWriter already
does this, so this patch modifies TempDir to not fail in the dtor,
adding a `close` method for handling errors on destruction.
The current suite of benchmarks for the standard distribution take a significant
amount of time to run, but it's unclear whether we're gaining any benefit from
running them. Some specific pain points:
* No one is looking at the data generated by the benchmarks. We have no graphs
or analysis of what's happening, so all the data is largely being cast into
the void.
* No benchmark has ever uncovered a bug, they have always run successfully.
* Benchmarks not only take a significant amount of time to run, but also take a
significant amount of time to compile. I don't think we should mitigate this
for now because it's useful to ensure that they do indeed still compile.
This commit disables --bench test runs by default as part of `make check`,
flipping the NO_BENCH environment variable to a PLEASE_BENCH variable which will
manually enable benchmarking. If and when a dedicated bot is set up for
benchmarking, this flag can be enabled on that bot.
This pull request fixes#12881.
Two caveats:
1. As explained in the commit message, this doesn't include a regression test. If this is unacceptable, please let me know, I'll see what I can do.
1. I'm getting some test failures on make check, all from debuginfo. I suspect this is due to #13680 and not related to my changes (I have GDB 7.7). This is the list of failed tests:
> [debuginfo-gdb] debuginfo/basic-types-globals.rs
> [debuginfo-gdb] debuginfo/basic-types-mut-globals.rs
> [debuginfo-gdb] debuginfo/basic-types.rs
> [debuginfo-gdb] debuginfo/borrowed-basic.rs
> [debuginfo-gdb] debuginfo/borrowed-managed-basic.rs
> [debuginfo-gdb] debuginfo/borrowed-struct.rs
> [debuginfo-gdb] debuginfo/borrowed-unique-basic.rs
> [debuginfo-gdb] debuginfo/box.rs
> [debuginfo-gdb] debuginfo/by-value-non-immediate-argument.rs
> [debuginfo-gdb] debuginfo/by-value-self-argument-in-trait-impl.rs
> [debuginfo-gdb] debuginfo/closure-in-generic-function.rs
> [debuginfo-gdb] debuginfo/evec-in-struct.rs
> [debuginfo-gdb] debuginfo/function-arg-initialization.rs
> [debuginfo-gdb] debuginfo/function-prologue-stepping-no-split-stack.rs
> [debuginfo-gdb] debuginfo/generic-function.rs
> [debuginfo-gdb] debuginfo/generic-functions-nested.rs
> [debuginfo-gdb] debuginfo/generic-method-on-generic-struct.rs
> [debuginfo-gdb] debuginfo/generic-static-method-on-struct-and-enum.rs
> [debuginfo-gdb] debuginfo/generic-struct.rs
> [debuginfo-gdb] debuginfo/lexical-scope-in-stack-closure.rs
> [debuginfo-gdb] debuginfo/lexical-scope-in-unique-closure.rs
> [debuginfo-gdb] debuginfo/method-on-generic-struct.rs
> [debuginfo-gdb] debuginfo/method-on-tuple-struct.rs
> [debuginfo-gdb] debuginfo/name-shadowing-and-scope-nesting.rs
> [debuginfo-gdb] debuginfo/recursive-struct.rs
> [debuginfo-gdb] debuginfo/self-in-generic-default-method.rs
> [debuginfo-gdb] debuginfo/shadowed-argument.rs
> [debuginfo-gdb] debuginfo/shadowed-variable.rs
> [debuginfo-gdb] debuginfo/simd.rs
> [debuginfo-gdb] debuginfo/simple-lexical-scope.rs
> [debuginfo-gdb] debuginfo/simple-struct.rs
> [debuginfo-gdb] debuginfo/simple-tuple.rs
> [debuginfo-gdb] debuginfo/static-method-on-struct-and-enum.rs
> [debuginfo-gdb] debuginfo/tuple-struct.rs
> [debuginfo-gdb] debuginfo/var-captured-in-nested-closure.rs
> [debuginfo-gdb] debuginfo/var-captured-in-sendable-closure.rs
> [debuginfo-gdb] debuginfo/var-captured-in-stack-closure.rs
I can provide the full output on request.
This allows writing a regex to filter tests more precisely, rather than having to list long paths e.g.
```
$ ./stdtest-x86_64-unknown-linux-gnu 'vec.*clone'
running 2 tests
test vec::tests::test_clone ... ok
test vec::tests::test_clone_from ... ok
test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured
```
The regex change is fully backwards compatible, since test names are Rust
identifiers + `:`, and hence not special regex characters.
(See commits for details.)
## Process API
The existing APIs for spawning processes took strings for the command
and arguments, but the underlying system may not impose utf8 encoding,
so this is overly limiting.
The assumption we actually want to make is just that the command and
arguments are viewable as [u8] slices with no interior NULLs, i.e., as
CStrings. The ToCStr trait is a handy bound for types that meet this
requirement (such as &str and Path).
However, since the commands and arguments are often a mixture of
strings and paths, it would be inconvenient to take a slice with a
single T: ToCStr bound. So this patch revamps the process creation API
to instead use a builder-style interface, called `Command`, allowing
arguments to be added one at a time with differing ToCStr
implementations for each.
The initial cut of the builder API has some drawbacks that can be
addressed once issue #13851 (libstd as a facade) is closed. These are
detailed as FIXMEs.
## Dynamic library API
`std::unstable::dynamic_library::open_external` currently takes a
`Path`, but because `Paths` produce normalized strings, this can
change the semantics of lookups in a given environment. This patch
generalizes the function to take a `ToCStr`-bounded type, which
includes both `Path`s and `str`s.
## ToCStr API
Adds ToCStr impl for &Path and ~str. This is a stopgap until DST (#12938) lands.
Until DST lands, we cannot decompose &str into & and str, so we cannot
usefully take ToCStr arguments by reference (without forcing an
additional & around &str). So we are instead temporarily adding an
instance for &Path and ~str, so that we can take ToCStr as owned. When
DST lands, the &Path instance should be removed, the string instances
should be revisted, and arguments bound by ToCStr should be passed by
reference.
FIXMEs have been added accordingly.
## Tickets closed
Closes#11650.
Closes#7928.
This adds the flag --color, which allows the user to force coloring or
turn it off. The default behavior stays the same as before (colorize, if
output goes to tty).
Why this is beneficial is explained in issue #12881.
Please note that this commit doesn't include any regression tests. I
thought about how I'd write a test for this and it doesn't seem to be
worth the effort to me for a UI change like this.
Fixes#12881.
Previously the longer hand-written usage string was never being printed:
theoretically it was trying to detect when precisely `--help` was
passed (but not `-h`), but the getopts framework was considering a check
for the presence of `-h` to be a check for that of `--help` too,
i.e. the code was always going through the `-h` path.
This changes it to print the extended usage for both `-h` and `--help`,
meaning that it does actually appear correctly.
Submitting PR again, because I cannot reopen#13349, and github does not attach new patch to that PR.
=======
Optimize `Once::doit`: perform optimistic check that initializtion is
already completed. `load` is much cheaper than `fetch_add` at least
on x86_64.
Verified with this test:
```
static mut o: one::Once = one::ONCE_INIT;
unsafe {
loop {
let start = time::precise_time_ns();
let iters = 50000000u64;
for _ in range(0, iters) {
o.doit(|| { println!("once!"); });
}
let end = time::precise_time_ns();
let ps_per_iter = 1000 * (end - start) / iters;
println!("{} ps per iter", ps_per_iter);
// confuse the optimizer
o.doit(|| { println!("once!"); });
}
}
```
Test executed on Mac, Intel Core i7 2GHz. Result is:
* 20ns per iteration without patch
* 4ns per iteration with this patch applied
Once.doit could be even faster (800ps per iteration), if `doit` function
was split into a pair of `doit`/`doit_slow`, and `doit` marked as
`#[inline]` like this:
```
#[inline(always)]
pub fn doit(&self, f: ||) {
if self.cnt.load(atomics::SeqCst) < 0 {
return
}
self.doit_slow(f);
}
fn doit_slow(&self, f: ||) { ... }
```
Teach SVH computation to ignore more implementation artifacts.
In particular, this version of strict version hash (SVH) works much
like the deriving(Hash)-based implementation did, except that it
deliberately:
1. skips over content known not affect the generated crates, and,
2. uses a content-based hash for names instead of using the value of
the `Name` index itself, which can differ depending on the order
in which strings are interned (which in turn is affected by
e.g. the presence of `--cfg` options on the command line).
Fix#14132.
(Only after adding the tests did I realize that this is not really a
special case at the AST level; as far as the visitor is concerned,
`int` and `i32` and `i64` are just idents.)
Namely: non-pub `use` declarations *are* significant to the SVH
computation, since they can change which traits are part of the method
resolution step, and thus affect which methods get called from the
(potentially inlined) code.
In particular, this version of strict version hash (SVH) works much
like the deriving(Hash)-based implementation did, except that uses a
content-based hash that filters rustc implementation artifacts and
surface syntax artifacts.
Fix#14132.
`std::unstable::dynamic_library::open_external` currently takes a
`Path`, but because `Paths` produce normalized strings, this can
change the semantics of lookups in a given environment. This patch
generalizes the function to take a `ToCStr`-bounded type, which
includes both `Path`s and `str`s.
Closes#11650.
The existing APIs for spawning processes took strings for the command
and arguments, but the underlying system may not impose utf8 encoding,
so this is overly limiting.
The assumption we actually want to make is just that the command and
arguments are viewable as [u8] slices with no interior NULLs, i.e., as
CStrings. The ToCStr trait is a handy bound for types that meet this
requirement (such as &str and Path).
However, since the commands and arguments are often a mixture of
strings and paths, it would be inconvenient to take a slice with a
single T: ToCStr bound. So this patch revamps the process creation API
to instead use a builder-style interface, called `Command`, allowing
arguments to be added one at a time with differing ToCStr
implementations for each.
The initial cut of the builder API has some drawbacks that can be
addressed once issue #13851 (libstd as a facade) is closed. These are
detailed as FIXMEs.
Closes#11650.
[breaking-change]
This is a stopgap until DST (#12938) lands.
Until DST lands, we cannot decompose &str into & and str, so we cannot
usefully take ToCStr arguments by reference (without forcing an
additional & around &str). So we are instead temporarily adding an
instance for &Path and StrBuf, so that we can take ToCStr as owned. When
DST lands, the &Path instance should be removed, the string instances
should be revisted, and arguments bound by ToCStr should be passed by
reference.
FIXMEs have been added accordingly.
