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Update licenseck.py to not check for copyright #2

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Update licenseck.py to not check for copyright #2

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iKevinY
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@iKevinY iKevinY commented Jan 21, 2015

This should fix make tidy and also implements some changes I was going to make in a separate PR.

@iKevinY
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iKevinY commented Jan 22, 2015

Ugh, it just dawned on me that the two PRs can be merged simultaneously with no break in continuity for Travis builds. Making this PR against the main repository instead; sorry for the notification noise!

@iKevinY iKevinY closed this Jan 22, 2015
steveklabnik pushed a commit that referenced this pull request Aug 3, 2015
steveklabnik pushed a commit that referenced this pull request Aug 10, 2016
rustc_trans: don't Assert(Overflow(Neg)) when overflow checks are off.

Generic functions using `Neg` on primitive types would panic even in release mode, with MIR trans.
The solution is a bit hacky, as I'm checking the message, since there's no dedicated `CheckedUnOp`.

Blocks Servo rustup ([failure #1](http://build.servo.org/builders/linux-rel/builds/2477/steps/test_3/logs/stdio), [failure #2](http://build.servo.org/builders/mac-rel-css/builds/2364/steps/test/logs/stdio)) - this should be the last hurdle, it affects only one test.
steveklabnik pushed a commit that referenced this pull request Jan 23, 2017
For a given file

```rust
trait A { fn foo(&self) {} }
trait B : A { fn foo(&self) {} }

fn bar<T: B>(a: &T) {
  a.foo()
}
```

provide the following output

```
error[E0034]: multiple applicable items in scope
 --> file.rs:6:5
  |
6 |   a.foo(1)
  |     ^^^ multiple `foo` found
  |
note: candidate #1 is defined in the trait `A`
 --> file.rs:2:11
  |
2 | trait A { fn foo(&self, a: usize) {} }
  |           ^^^^^^^^^^^^^^^^^^^^^^^^^^
help: to use it here write `A::foo(&a, 1)` instead
 --> file.rs:6:5
  |
6 |   a.foo(1)
  |     ^^^
note: candidate #2 is defined in the trait `B`
 --> file.rs:3:15
  |
3 | trait B : A { fn foo(&self, a: usize) {} }
  |               ^^^^^^^^^^^^^^^^^^^^^^^^^^
help: to use it here write `B::foo(&a, 1)` instead
 --> file.rs:6:5
  |
6 |   a.foo(1)
  |     ^^^
```
steveklabnik pushed a commit that referenced this pull request Jan 23, 2017
E0034: provide disambiguated syntax for candidates

For a given file

```rust
trait A { fn foo(&self) {} }
trait B : A { fn foo(&self) {} }

fn bar<T: B>(a: &T) {
  a.foo()
}
```

provide the following output

```
error[E0034]: multiple applicable items in scope
 --> file.rs:6:5
  |
6 |   a.foo(1)
  |     ^^^ multiple `foo` found
  |
note: candidate #1 is defined in the trait `A`
 --> file.rs:2:11
  |
2 | trait A { fn foo(&self, a: usize) {} }
  |           ^^^^^^^^^^^^^^^^^^^^^^^^^^
help: to use it here write `A::foo(&a, 1)` instead
 --> file.rs:6:5
  |
6 |   a.foo(1)
  |     ^^^
note: candidate #2 is defined in the trait `B`
 --> file.rs:3:15
  |
3 | trait B : A { fn foo(&self, a: usize) {} }
  |               ^^^^^^^^^^^^^^^^^^^^^^^^^^
help: to use it here write `B::foo(&a, 1)` instead
 --> file.rs:6:5
  |
6 |   a.foo(1)
  |     ^^^
```

Fix rust-lang#37767.
steveklabnik pushed a commit that referenced this pull request Feb 9, 2017
LeakSanitizer, ThreadSanitizer, AddressSanitizer and MemorySanitizer support

```
$ cargo new --bin leak && cd $_

$ edit Cargo.toml && tail -n3 $_
```

``` toml
[profile.dev]
opt-level = 1
```

```
$ edit src/main.rs && cat $_
```

``` rust
use std::mem;

fn main() {
    let xs = vec![0, 1, 2, 3];
    mem::forget(xs);
}
```

```
$ RUSTFLAGS="-Z sanitizer=leak" cargo run --target x86_64-unknown-linux-gnu; echo $?
    Finished dev [optimized + debuginfo] target(s) in 0.0 secs
     Running `target/debug/leak`

=================================================================
==10848==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 16 byte(s) in 1 object(s) allocated from:
    #0 0x557c3488db1f in __interceptor_malloc /shared/rust/checkouts/lsan/src/compiler-rt/lib/lsan/lsan_interceptors.cc:55
    #1 0x557c34888aaa in alloc::heap::exchange_malloc::h68f3f8b376a0da42 /shared/rust/checkouts/lsan/src/liballoc/heap.rs:138
    #2 0x557c34888afc in leak::main::hc56ab767de6d653a $PWD/src/main.rs:4
    #3 0x557c348c0806 in __rust_maybe_catch_panic ($PWD/target/debug/leak+0x3d806)

SUMMARY: LeakSanitizer: 16 byte(s) leaked in 1 allocation(s).
23
```

```
$ cargo new --bin racy && cd $_

$ edit src/main.rs && cat $_
```

``` rust
use std::thread;

static mut ANSWER: i32 = 0;

fn main() {
    let t1 = thread::spawn(|| unsafe { ANSWER = 42 });
    unsafe {
        ANSWER = 24;
    }
    t1.join().ok();
}
```

```
$ RUSTFLAGS="-Z sanitizer=thread" cargo run --target x86_64-unknown-linux-gnu; echo $?
==================
WARNING: ThreadSanitizer: data race (pid=12019)
  Write of size 4 at 0x562105989bb4 by thread T1:
    #0 racy::main::_$u7b$$u7b$closure$u7d$$u7d$::hbe13ea9e8ac73f7e $PWD/src/main.rs:6 (racy+0x000000010e3f)
    #1 _$LT$std..panic..AssertUnwindSafe$LT$F$GT$$u20$as$u20$core..ops..FnOnce$LT$$LP$$RP$$GT$$GT$::call_once::h2e466a92accacc78 /shared/rust/checkouts/lsan/src/libstd/panic.rs:296 (racy+0x000000010cc5)
    #2 std::panicking::try::do_call::h7f4d2b38069e4042 /shared/rust/checkouts/lsan/src/libstd/panicking.rs:460 (racy+0x00000000c8f2)
    #3 __rust_maybe_catch_panic <null> (racy+0x0000000b4e56)
    #4 std::panic::catch_unwind::h31ca45621ad66d5a /shared/rust/checkouts/lsan/src/libstd/panic.rs:361 (racy+0x00000000b517)
    #5 std::thread::Builder::spawn::_$u7b$$u7b$closure$u7d$$u7d$::hccfc37175dea0b01 /shared/rust/checkouts/lsan/src/libstd/thread/mod.rs:357 (racy+0x00000000c226)
    #6 _$LT$F$u20$as$u20$alloc..boxed..FnBox$LT$A$GT$$GT$::call_box::hd880bbf91561e033 /shared/rust/checkouts/lsan/src/liballoc/boxed.rs:605 (racy+0x00000000f27e)
    #7 std::sys::imp::thread::Thread::new::thread_start::hebdfc4b3d17afc85 <null> (racy+0x0000000abd40)

  Previous write of size 4 at 0x562105989bb4 by main thread:
    #0 racy::main::h23e6e5ca46d085c3 $PWD/src/main.rs:8 (racy+0x000000010d7c)
    #1 __rust_maybe_catch_panic <null> (racy+0x0000000b4e56)
    #2 __libc_start_main <null> (libc.so.6+0x000000020290)

  Location is global 'racy::ANSWER::h543d2b139f819b19' of size 4 at 0x562105989bb4 (racy+0x0000002f8bb4)

  Thread T1 (tid=12028, running) created by main thread at:
    #0 pthread_create /shared/rust/checkouts/lsan/src/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc:902 (racy+0x00000001aedb)
    #1 std::sys::imp::thread::Thread::new::hce44187bf4a36222 <null> (racy+0x0000000ab9ae)
    #2 std::thread::spawn::he382608373eb667e /shared/rust/checkouts/lsan/src/libstd/thread/mod.rs:412 (racy+0x00000000b5aa)
    #3 racy::main::h23e6e5ca46d085c3 $PWD/src/main.rs:6 (racy+0x000000010d5c)
    #4 __rust_maybe_catch_panic <null> (racy+0x0000000b4e56)
    #5 __libc_start_main <null> (libc.so.6+0x000000020290)

SUMMARY: ThreadSanitizer: data race $PWD/src/main.rs:6 in racy::main::_$u7b$$u7b$closure$u7d$$u7d$::hbe13ea9e8ac73f7e
==================
ThreadSanitizer: reported 1 warnings
66
```

```
$ cargo new --bin oob && cd $_

$ edit src/main.rs && cat $_
```

``` rust
fn main() {
    let xs = [0, 1, 2, 3];
    let y = unsafe { *xs.as_ptr().offset(4) };
}
```

```
$ RUSTFLAGS="-Z sanitizer=address" cargo run --target x86_64-unknown-linux-gnu; echo $?
=================================================================
==13328==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fff29f3ecd0 at pc 0x55802dc6bf7e bp 0x7fff29f3ec90 sp 0x7fff29f3ec88
READ of size 4 at 0x7fff29f3ecd0 thread T0
    #0 0x55802dc6bf7d in oob::main::h0adc7b67e5feb2e7 $PWD/src/main.rs:3
    #1 0x55802dd60426 in __rust_maybe_catch_panic ($PWD/target/debug/oob+0xfe426)
    #2 0x55802dd58dd9 in std::rt::lang_start::hb2951fc8a59d62a7 ($PWD/target/debug/oob+0xf6dd9)
    #3 0x55802dc6c002 in main ($PWD/target/debug/oob+0xa002)
    #4 0x7fad8c3b3290 in __libc_start_main (/usr/lib/libc.so.6+0x20290)
    #5 0x55802dc6b719 in _start ($PWD/target/debug/oob+0x9719)

Address 0x7fff29f3ecd0 is located in stack of thread T0 at offset 48 in frame
    #0 0x55802dc6bd5f in oob::main::h0adc7b67e5feb2e7 $PWD/src/main.rs:1

  This frame has 1 object(s):
    [32, 48) 'xs' <== Memory access at offset 48 overflows this variable
HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext
      (longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-buffer-overflow $PWD/src/main.rs:3 in oob::main::h0adc7b67e5feb2e7
Shadow bytes around the buggy address:
  0x1000653dfd40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000653dfd50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000653dfd60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000653dfd70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000653dfd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x1000653dfd90: 00 00 00 00 f1 f1 f1 f1 00 00[f3]f3 00 00 00 00
  0x1000653dfda0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000653dfdb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000653dfdc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000653dfdd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000653dfde0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Heap right redzone:      fb
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack partial redzone:   f4
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
==13328==ABORTING
1
```

```
$ cargo new --bin uninit && cd $_

$ edit src/main.rs && cat $_
```

``` rust
use std::mem;

fn main() {
    let xs: [u8; 4] = unsafe { mem::uninitialized() };
    let y = xs[0] + xs[1];
}
```

```
$ RUSTFLAGS="-Z sanitizer=memory" cargo run; echo $?
==30198==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x563f4b6867da in uninit::main::hc2731cd4f2ed48f8 $PWD/src/main.rs:5
    #1 0x563f4b7033b6 in __rust_maybe_catch_panic ($PWD/target/debug/uninit+0x873b6)
    #2 0x563f4b6fbd69 in std::rt::lang_start::hb2951fc8a59d62a7 ($PWD/target/debug/uninit+0x7fd69)
    #3 0x563f4b6868a9 in main ($PWD/target/debug/uninit+0xa8a9)
    #4 0x7fe844354290 in __libc_start_main (/usr/lib/libc.so.6+0x20290)
    #5 0x563f4b6864f9 in _start ($PWD/target/debug/uninit+0xa4f9)

SUMMARY: MemorySanitizer: use-of-uninitialized-value $PWD/src/main.rs:5 in uninit::main::hc2731cd4f2ed48f8
Exiting
77
```
steveklabnik pushed a commit that referenced this pull request Feb 28, 2017
steveklabnik pushed a commit that referenced this pull request Mar 8, 2017
Group "missing variable bind" spans in `or` matches and clarify wording
for the two possible cases: when a variable from the first pattern is
not in any of the subsequent patterns, and when a variable in any of the
other patterns is not in the first one.

Before:

```
error[E0408]: variable `a` from pattern #1 is not bound in pattern #2
  --> file.rs:10:23
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                       ^^^^^^^^^^^ pattern doesn't bind `a`

error[E0408]: variable `b` from pattern #2 is not bound in pattern #1
  --> file.rs:10:32
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                                ^ pattern doesn't bind `b`

error[E0408]: variable `a` from pattern #1 is not bound in pattern #3
  --> file.rs:10:37
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                                     ^^^^^^^^ pattern doesn't bind `a`

error[E0408]: variable `d` from pattern #1 is not bound in pattern #3
  --> file.rs:10:37
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                                     ^^^^^^^^ pattern doesn't bind `d`

error[E0408]: variable `c` from pattern #3 is not bound in pattern #1
  --> file.rs:10:43
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                                           ^ pattern doesn't bind `c`

error[E0408]: variable `d` from pattern #1 is not bound in pattern #4
  --> file.rs:10:48
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                                                ^^^^^^^^ pattern doesn't bind `d`

error: aborting due to 6 previous errors
```

After:

```
error[E0408]: variable `a` is not bound in all patterns
  --> file.rs:20:37
   |
20 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => {
intln!("{:?}", a); }
   |               -       ^^^^^^^^^^^   ^^^^^^^^         - variable
t in all patterns
   |               |       |             |
   |               |       |             pattern doesn't bind `a`
   |               |       pattern doesn't bind `a`
   |               variable not in all patterns

error[E0408]: variable `d` is not bound in all patterns
  --> file.rs:20:37
   |
20 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => {
intln!("{:?}", a); }
   |                  -          -       ^^^^^^^^   ^^^^^^^^ pattern
esn't bind `d`
   |                  |          |       |
   |                  |          |       pattern doesn't bind `d`
   |                  |          variable not in all patterns
   |                  variable not in all patterns

error[E0408]: variable `b` is not bound in all patterns
  --> file.rs:20:37
   |
20 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => {
intln!("{:?}", a); }
   |         ^^^^^^^^^^^            -    ^^^^^^^^   ^^^^^^^^ pattern
esn't bind `b`
   |         |                      |    |
   |         |                      |    pattern doesn't bind `b`
   |         |                      variable not in all patterns
   |         pattern doesn't bind `b`

error[E0408]: variable `c` is not bound in all patterns
  --> file.rs:20:48
   |
20 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => {
intln!("{:?}", a); }
   |         ^^^^^^^^^^^   ^^^^^^^^^^^         -    ^^^^^^^^ pattern
esn't bind `c`
   |         |             |                   |
   |         |             |                   variable not in all
tterns
   |         |             pattern doesn't bind `c`
   |         pattern doesn't bind `c`

error: aborting due to 4 previous errors
```

* Have only one presentation for binding consistency errors
* Point to same binding in multiple patterns when possible
* Check inconsistent bindings in all arms
* Simplify wording of diagnostic message
* Sort emition and spans of binding errors for deterministic output
steveklabnik pushed a commit that referenced this pull request Mar 8, 2017
Clean up "pattern doesn't bind x" messages

Group "missing variable bind" spans in `or` matches and clarify wording
for the two possible cases: when a variable from the first pattern is
not in any of the subsequent patterns, and when a variable in any of the
other patterns is not in the first one.

Before:

```rust
error[E0408]: variable `a` from pattern #1 is not bound in pattern #2
  --> file.rs:10:23
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                       ^^^^^^^^^^^ pattern doesn't bind `a`

error[E0408]: variable `b` from pattern #2 is not bound in pattern #1
  --> file.rs:10:32
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                                ^ pattern doesn't bind `b`

error[E0408]: variable `a` from pattern #1 is not bound in pattern #3
  --> file.rs:10:37
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                                     ^^^^^^^^ pattern doesn't bind `a`

error[E0408]: variable `d` from pattern #1 is not bound in pattern #3
  --> file.rs:10:37
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                                     ^^^^^^^^ pattern doesn't bind `d`

error[E0408]: variable `c` from pattern #3 is not bound in pattern #1
  --> file.rs:10:43
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                                           ^ pattern doesn't bind `c`

error[E0408]: variable `d` from pattern #1 is not bound in pattern #4
  --> file.rs:10:48
   |
10 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                                                ^^^^^^^^ pattern doesn't bind `d`

error: aborting due to 6 previous errors
```

After:

```rust
error[E0408]: variable `d` is not bound in all patterns
  --> $DIR/issue-39698.rs:20:37
   |
20 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                  -          -       ^^^^^^^^   ^^^^^^^^ pattern doesn't bind `d`
   |                  |          |       |
   |                  |          |       pattern doesn't bind `d`
   |                  |          variable not in all patterns
   |                  variable not in all patterns

error[E0408]: variable `c` is not bound in all patterns
  --> $DIR/issue-39698.rs:20:48
   |
20 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |         ^^^^^^^^^^^   ^^^^^^^^^^^         -    ^^^^^^^^ pattern doesn't bind `c`
   |         |             |                   |
   |         |             |                   variable not in all patterns
   |         |             pattern doesn't bind `c`
   |         pattern doesn't bind `c`

error[E0408]: variable `a` is not bound in all patterns
  --> $DIR/issue-39698.rs:20:37
   |
20 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |               -       ^^^^^^^^^^^   ^^^^^^^^         - variable not in all patterns
   |               |       |             |
   |               |       |             pattern doesn't bind `a`
   |               |       pattern doesn't bind `a`
   |               variable not in all patterns

error[E0408]: variable `b` is not bound in all patterns
  --> $DIR/issue-39698.rs:20:37
   |
20 |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |         ^^^^^^^^^^^            -    ^^^^^^^^   ^^^^^^^^ pattern doesn't bind `b`
   |         |                      |    |
   |         |                      |    pattern doesn't bind `b`
   |         |                      variable not in all patterns
   |         pattern doesn't bind `b`

error: aborting due to 4 previous errors
```

Fixes rust-lang#39698.
steveklabnik pushed a commit that referenced this pull request Jun 5, 2017
Without that flag, LLVM generates unaligned memory access instructions, which are not allowed on ARMv5.

For example, the 'hello world' example from `cargo --new` failed with:
```
$ ./hello
Hello, world!
thread 'main' panicked at 'assertion failed: end <= len', src/libcollections/vec.rs:1113
note: Run with `RUST_BACKTRACE=1` for a backtrace.
```

I traced this error back to the following assembler code in `BufWriter::flush_buf`:
```
    6f44:       e28d0018        add     r0, sp, rust-lang#24
[...]
    6f54:       e280b005        add     fp, r0, #5
[...]
    7018:       e5cd001c        strb    r0, [sp, rust-lang#28]
    701c:       e1a0082a        lsr     r0, sl, rust-lang#16
    7020:       03a01001        moveq   r1, #1
    7024:       e5cb0002        strb    r0, [fp, #2]
    7028:       e1cba0b0        strh    sl, [fp]
```

Note that `fp` points to `sp + 29`, so the three `str*`-instructions should fill up a 32bit - value at `sp + 28`, which is later used as the value `n` in `Ok(n) => written += n`. This doesn't work on ARMv5 as the `strh` can't write to the unaligned contents of `fp`, so the upper bits of `n` won't get cleared, leading to the assertion failure in Vec::drain.

With `+strict-align`, the code works as expected.
steveklabnik pushed a commit that referenced this pull request Jun 5, 2017
ARMv5 needs +strict-align

Without that flag, LLVM generates unaligned memory access instructions, which are not allowed on ARMv5.

For example, the 'hello world' example from `cargo --new` failed with:
```
$ ./hello
Hello, world!
thread 'main' panicked at 'assertion failed: end <= len', src/libcollections/vec.rs:1113
note: Run with `RUST_BACKTRACE=1` for a backtrace.
```

I traced this error back to the following assembler code in `BufWriter::flush_buf`:
```
    6f44:       e28d0018        add     r0, sp, rust-lang#24
[...]
    6f54:       e280b005        add     fp, r0, #5
[...]
    7018:       e5cd001c        strb    r0, [sp, rust-lang#28]
    701c:       e1a0082a        lsr     r0, sl, rust-lang#16
    7020:       03a01001        moveq   r1, #1
    7024:       e5cb0002        strb    r0, [fp, #2]
    7028:       e1cba0b0        strh    sl, [fp]
```

Note that `fp` points to `sp + 29`, so the three `str*`-instructions should fill up a 32bit - value at `sp + 28`, which is later used as the value `n` in `Ok(n) => written += n`. This doesn't work on ARMv5 as the `strh` can't write to the unaligned contents of `fp`, so the upper bits of `n` won't get cleared, leading to the assertion failure in Vec::drain.

With `+strict-align`, the code works as expected.
steveklabnik pushed a commit that referenced this pull request Dec 30, 2017
…r=michaelwoerister

Set the dwarf linkage_name to the mangled name

ref rust-lang#46453

@michaelwoerister or anyone else who knows, i'm not sure if this is the correct instance to pass here (or how to get the correct one precisely): https://github.com//m4b/rust/blob/5a94a48678ec0a20ea6a63a783e63546bf9459b1/src/librustc_trans/debuginfo/namespace.rs#L36

So don't merge this yet, I'd like to learn about correct instance first; however, I think this already fixes a bunch of weirdness i'm seeing debugging from time to time, not to mention backtraces in gdb via `bt` are now ~readable~ meaningful 🎉

E.g.:

new:
```
(gdb) bt
#0  <inline::Foo as core::convert::From<()>>::from () at /home/m4b/tmp/bad_debug/inline.rs:11
#1  0x000055555555a35d in inline::deadbeef () at /home/m4b/tmp/bad_debug/inline.rs:16
#2  0x000055555555a380 in inline::main () at /home/m4b/tmp/bad_debug/inline.rs:20
```

old:
```
(gdb) bt
#0  inline::{{impl}}::from () at /home/m4b/tmp/bad_debug/inline.rs:11
#1  0x000055555555b0ed in inline::deadbeef () at /home/m4b/tmp/bad_debug/inline.rs:16
#2  0x000055555555b120 in inline::main () at /home/m4b/tmp/bad_debug/inline.rs:20
```
steveklabnik pushed a commit that referenced this pull request Jan 25, 2018
When given the following code:

```rust
fn give_any<F: for<'r> FnOnce(&'r ())>(f: F) {
    f(&());
}

fn main() {
    let mut x = None;
    give_any(|y| x = Some(y));
}
```

provide a custom error:

```
error: borrowed data cannot be moved outside of its closure
 --> file.rs:7:27
  |
6 |     let mut x = None;
  |         ----- binding declared outside of closure
7 |     give_any(|y| x = Some(y));
  |              ---          ^ cannot be assigned to binding outside of its closure
  |              |
  |              closure you can't escape
```

instead of the generic lifetime error:

```
error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
 --> file.rs:7:27
  |
7 |     give_any(|y| x = Some(y));
  |                           ^
  |
note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the body at 7:14...
 --> file.rs:7:14
  |
7 |     give_any(|y| x = Some(y));
  |              ^^^^^^^^^^^^^^^
note: ...so that expression is assignable (expected &(), found &())
 --> file.rs:7:27
  |
7 |     give_any(|y| x = Some(y));
  |                           ^
note: but, the lifetime must be valid for the block suffix following statement 0 at 6:5...
 --> file.rs:6:5
  |
6 | /     let mut x = None;
7 | |     give_any(|y| x = Some(y));
8 | | }
  | |_^
note: ...so that variable is valid at time of its declaration
 --> file.rs:6:9
  |
6 |     let mut x = None;
  |         ^^^^^
```
steveklabnik pushed a commit that referenced this pull request Jan 25, 2018
…sakis

Custom error when moving arg outside of its closure

When given the following code:

```rust
fn give_any<F: for<'r> FnOnce(&'r ())>(f: F) {
    f(&());
}

fn main() {
    let mut x = None;
    give_any(|y| x = Some(y));
}
```

provide a custom error:

```
error: borrowed data cannot be moved outside of its closure
 --> file.rs:7:27
  |
6 |     let mut x = None;
  |         ----- borrowed data cannot be moved into here...
7 |     give_any(|y| x = Some(y));
  |              ---          ^ cannot be moved outside of its closure
  |              |
  |              ...because it cannot outlive this closure
```

instead of the generic lifetime error:

```
error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
 --> file.rs:7:27
  |
7 |     give_any(|y| x = Some(y));
  |                           ^
  |
note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the body at 7:14...
 --> file.rs:7:14
  |
7 |     give_any(|y| x = Some(y));
  |              ^^^^^^^^^^^^^^^
note: ...so that expression is assignable (expected &(), found &())
 --> file.rs:7:27
  |
7 |     give_any(|y| x = Some(y));
  |                           ^
note: but, the lifetime must be valid for the block suffix following statement 0 at 6:5...
 --> file.rs:6:5
  |
6 | /     let mut x = None;
7 | |     give_any(|y| x = Some(y));
8 | | }
  | |_^
note: ...so that variable is valid at time of its declaration
 --> file.rs:6:9
  |
6 |     let mut x = None;
  |         ^^^^^
```

Fix rust-lang#45983.
steveklabnik pushed a commit that referenced this pull request May 3, 2018
Building for x86_64-unknown-linux-musl currently results in an executable lacking debug information for musl libc itself. If you request a backtrace in GDB while control flow is within musl – including sycalls made by musl – the result looks like:

#0  0x0000000000434b46 in __cp_end ()
#1  0x0000000000432dbd in __syscall_cp_c ()
#2  0x0000000000000000 in ?? ()

i.e. not very helpful. Adding --enable-debug resolves this, and --enable-optimize re-enables optimisations which default to off given the previous flag.
steveklabnik pushed a commit that referenced this pull request May 3, 2018
Add --enable-debug flag to musl CI build script

Building for x86_64-unknown-linux-musl currently results in an executable lacking debug information for musl libc itself. If you request a backtrace in GDB while control flow is within musl – including sycalls made by musl – the result looks like:

```
#0  0x0000000000434b46 in __cp_end ()
#1  0x0000000000432dbd in __syscall_cp_c ()
#2  0x0000000000000000 in ?? ()
```

i.e. not very helpful. Adding --enable-debug resolves this, and --enable-optimize re-enables optimisations which default to off given the previous flag.
steveklabnik pushed a commit that referenced this pull request May 21, 2018
There is a hot path through `opt_normalize_projection_type`:
- `try_start` does a cache lookup (#1).
- The result is a `NormalizedTy`.
- There are no unresolved type vars, so we call `complete`.
- `complete` does *another* cache lookup (#2), then calls
  `SnapshotMap::insert`.
- `insert` does *another* cache lookup (#3), inserting the same value
  that's already in the cache.

This patch optimizes this hot path by introducing `complete_normalized`,
for use when the value is known in advance to be a `NormalizedTy`. It
always avoids lookup #2. Furthermore, if the `NormalizedTy`'s
obligations are empty (the common case), we know that lookup #3 would be
a no-op, so we avoid it, while inserting a Noop into the `SnapshotMap`'s
undo log.
steveklabnik pushed a commit that referenced this pull request Oct 29, 2018
steveklabnik pushed a commit that referenced this pull request Jun 16, 2020
fix comment


add newline for tidy fmt error...


edit suggestion message


change the suggestion message to better handle cases with binding modes


Apply suggestions from estebank code review

Co-authored-by: Esteban Kuber <estebank@users.noreply.github.com>
edits to address source review


Apply suggestions from estebank code review #2

Co-authored-by: Esteban Kuber <estebank@users.noreply.github.com>
update test files
steveklabnik pushed a commit that referenced this pull request Jul 16, 2020
steveklabnik pushed a commit that referenced this pull request Jul 16, 2020
Stabilize `#[track_caller]`.

# Stabilization Report

RFC: [2091]
Tracking issue: rust-lang#47809

## Summary

From the [rustc-dev-guide chapter][dev-guide]:

> Take this example program:

```rust
fn main() {
    let foo: Option<()> = None;
    foo.unwrap(); // this should produce a useful panic message!
}
```

> Prior to Rust 1.42, panics like this `unwrap()` printed a location in libcore:

```
$ rustc +1.41.0 example.rs; example.exe
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value',...core\macros\mod.rs:15:40
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
```

> As of 1.42, we get a much more helpful message:

```
$ rustc +1.42.0 example.rs; example.exe
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', example.rs:3:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

> These error messages are achieved through a combination of changes to `panic!` internals to make use of `core::panic::Location::caller` and a number of `#[track_caller]` annotations in the standard library which propagate caller information.

The attribute adds an implicit caller location argument to the ABI of annotated functions, but does not affect the type or MIR of the function. We implement the feature entirely in codegen and in the const evaluator.

## Bottom Line

This PR stabilizes the use of `#[track_caller]` everywhere, including traits and extern blocks. It also stabilizes `core::panic::Location::caller`, although the use of that function in a const context remains gated by `#![feature(const_caller_location)]`.

The implementation for the feature already changed the output of panic messages for a number of std functions, as described in the [1.42 release announcement]. The attribute's use in `Index` and `IndexMut` traits is visible to users since 1.44.

## Tests

All of the tests for this feature live under [src/test/ui/rfc-2091-track-caller][tests] in the repo.

Noteworthy cases:

* [use of attr in std]
  * validates user-facing benefit of the feature
* [trait attribute inheritance]
  * covers subtle behavior designed during implementation and not RFC'd
* [const/codegen equivalence]
  * this was the result of a suspected edge case and investigation
* [diverging function support]
  * covers an unresolved question from the RFC
* [fn pointers and shims]
  * covers important potential sources of unsoundness

## Documentation

The rustc-dev-guide now has a chapter on [Implicit Caller Location][dev-guide].

I have an [open PR to the reference][attr-reference-pr] documenting the attribute.

The intrinsic's [wrapper] includes some examples as well.

## Implementation History

* 2019-10-02: [`#[track_caller]` feature gate (RFC 2091 1/N) rust-lang#65037](rust-lang#65037)
  * Picked up the patch that @ayosec had started on the feature gate.
* 2019-10-13: [Add `Instance::resolve_for_fn_ptr` (RFC 2091 #2/N) rust-lang#65182](rust-lang#65182)
* 2019-10-20: ~~[WIP Add MIR argument for #[track_caller] (RFC 2091 3/N) rust-lang#65258](rust-lang#65258
  * Abandoned approach to send location as a MIR argument.
* 2019-10-28: [`std::panic::Location` is a lang_item, add `core::intrinsics::caller_location` (RFC 2091 3/N) rust-lang#65664](rust-lang#65664)
* 2019-12-07: [Implement #[track_caller] attribute. (RFC 2091 4/N) rust-lang#65881](rust-lang#65881)
* 2020-01-04: [libstd uses `core::panic::Location` where possible. rust-lang#67137](rust-lang#67137)
* 2020-01-08: [`Option::{expect,unwrap}` and `Result::{expect, expect_err, unwrap, unwrap_err}` have `#[track_caller]` rust-lang#67887](rust-lang#67887)
* 2020-01-20: [Fix #[track_caller] and function pointers rust-lang#68302](rust-lang#68302) (fixed rust-lang#68178)
* 2020-03-23: [#[track_caller] in traits rust-lang#69251](rust-lang#69251)
* 2020-03-24: [#[track_caller] on core::ops::{Index, IndexMut}. rust-lang#70234](rust-lang#70234)
* 2020-04-08 [Support `#[track_caller]` on functions in `extern "Rust" { ... }` rust-lang#70916](rust-lang#70916)

## Unresolveds

### From the RFC

> Currently the RFC simply prohibit applying #[track_caller] to trait methods as a future-proofing
> measure.

**Resolved.** See the dev-guide documentation and the tests section above.

> Diverging functions should be supported.

**Resolved.** See the tests section above.

> The closure foo::{{closure}} should inherit most attributes applied to the function foo, ...

**Resolved.** This unknown was related to specifics of the implementation which were made irrelevant by the final implementation.

### Binary Size

I [instrumented track_caller to use custom sections][measure-size] in a local build and discovered relatively minor binary size usage for the feature overall. I'm leaving the issue open to discuss whether we want to upstream custom section support.

There's an [open issue to discuss mitigation strategies][mitigate-size]. Some decisions remain about the "right" strategies to reduce size without overly constraining the compiler implementation. I'd be excited to see someone carry that work forward but my opinion is that we shouldn't block stabilization on implementing compiler flags for redaction.

### Specialization

There's an [open issue][specialization] on the semantics of the attribute in specialization chains. I'm inclined to move forward with stabilization without an exact resolution here given that specialization is itself unstable, but I also think it should be an easy question to resolve.

### Location only points to the start of a call span

rust-lang#69977 was resolved by rust-lang#73182, and the next step should probably be to [extend `Location` with a notion of the end of a call](rust-lang#73554).

### Regression of std's panic messages

rust-lang#70963 should be resolved by serializing span hygeine to crate metadata: rust-lang#68686.

[2091]: https://github.com/rust-lang/rfcs/blob/master/text/2091-inline-semantic.md
[dev-guide]: https://rustc-dev-guide.rust-lang.org/codegen/implicit-caller-location.html
[specialization]: rust-lang#70293
[measure-size]: rust-lang#70579
[mitigate-size]: rust-lang#70580
[attr-reference-pr]: rust-lang/reference#742
[wrapper]: https://doc.rust-lang.org/nightly/core/panic/struct.Location.html#method.caller
[tests]: https://github.com/rust-lang/rust/tree/master/src/test/ui/rfc-2091-track-caller
[const/codegen equivalence]: https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2091-track-caller/caller-location-fnptr-rt-ctfe-equiv.rs
[diverging function support]: https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2091-track-caller/diverging-caller-location.rs
[use of attr in std]: https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2091-track-caller/std-panic-locations.rs
[fn pointers and shims]: https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2091-track-caller/tracked-fn-ptr-with-arg.rs
[trait attribute inheritance]: https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2091-track-caller/tracked-trait-impls.rs
[1.42 release announcement]: https://blog.rust-lang.org/2020/03/12/Rust-1.42.html#useful-line-numbers-in-option-and-result-panic-messages
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