Add support for elision in structured error messages #1

sophiajt · 2016-04-01T00:26:05Z

No description provided.

nikomatsakis · 2016-04-01T11:49:29Z

Looks good.

Save ids fix

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.

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) | ^^^ ```

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.

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 ```

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

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.

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, #24 [...] 6f54: e280b005 add fp, r0, #5 [...] 7018: e5cd001c strb r0, [sp, #28] 701c: e1a0082a lsr r0, sl, #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.

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, #24 [...] 6f54: e280b005 add fp, r0, #5 [...] 7018: e5cd001c strb r0, [sp, #28] 701c: e1a0082a lsr r0, sl, #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.

…crichton Allow atomic operations up to 32 bits The ARMv5te platform does not have instruction-level support for atomics, however the kernel provides [user space helpers] which can be used to perform atomic operations. When linked with `libgcc`, the atomic symbols needed by Rust will be provided, rather than CPU level intrinsics. [user space helpers]: https://www.kernel.org/doc/Documentation/arm/kernel_user_helpers.txt 32-bit versions of these kernel level helpers were introduced in Linux Kernel 2.6.12, and 64-bit version of these kernel level helpers were introduced in Linux Kernel 3.1. I have selected 32 bit versions as std currently only requires Linux version 2.6.18 and above as far as I am aware. As this target is specifically linux and gnueabi, it is reasonable to assume the Linux Kernel and libc will be available for the target. There is a large performance penalty, as we are not using CPU level intrinsics, however this penalty is likely preferable to not having the target at all. I have used this change in a custom target (along with xargo) to build std, as well as a number of higher level crates. ## Additional information For reference, here is what a a code snippet decompiles to: ```rust use std::sync::atomic::{AtomicIsize, Ordering}; #[no_mangle] pub extern fn foo(a: &AtomicIsize) -> isize { a.fetch_add(1, Ordering::SeqCst) } ``` ``` Disassembly of section .text.foo: 00000000 <foo>: 0: e92d4800 push {fp, lr} 4: e3a01001 mov r1, #1 8: ebfffffe bl 0 <__sync_fetch_and_add_4> c: e8bd8800 pop {fp, pc} ``` Which in turn is provided by `libgcc.a`, which has code which looks like this: ``` Disassembly of section .text: 00000000 <__sync_fetch_and_add_4>: 0: e92d40f8 push {r3, r4, r5, r6, r7, lr} 4: e1a05000 mov r5, r0 8: e1a07001 mov r7, r1 c: e59f6028 ldr r6, [pc, rust-lang#40] ; 3c <__sync_fetch_and_add_4+0x3c> 10: e5954000 ldr r4, [r5] 14: e1a02005 mov r2, r5 18: e1a00004 mov r0, r4 1c: e0841007 add r1, r4, r7 20: e1a0e00f mov lr, pc 24: e12fff16 bx r6 28: e3500000 cmp r0, #0 2c: 1afffff7 bne 10 <__sync_fetch_and_add_4+0x10> 30: e1a00004 mov r0, r4 34: e8bd40f8 pop {r3, r4, r5, r6, r7, lr} 38: e12fff1e bx lr 3c: ffff0fc0 .word 0xffff0fc0 ``` Where you can see the reference to `0xffff0fc0`, which is provided by the [user space helpers].

Fixup function_pointers2

@michaelwoerister

…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 ```

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.

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.

Merge upstream changes

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.

When encountering an unexisting method for a given trait where an associated function has the same name, suggest using the appropriate syntax, instead of using `help` text. When only one candidate is found, do not call it "candidate #1", just call it "the candidate".

Tweak output on E0599 for assoc fn used as method - Use suggestion instead of `help` when possible - Add primary span label - Remove incorrect `help` suggestion using incorrect syntax - Do not refer to only one possible candidate as `candidate #1`, refer to it as `the candidate`

Suggestion for 'static impl Trait return When encountering a named or anonymous sup requirement (for example, `&'a self`) and a `'static` impl Trait return type, suggest adding the `'_` lifetime constraing to the return type. Fix rust-lang#43719, rust-lang#51282. ``` error: cannot infer an appropriate lifetime --> $DIR/static-return-lifetime-infered.rs:17:16 | LL | fn iter_values_anon(&self) -> impl Iterator<Item=u32> { | ----------------------- this return type evaluates to the `'static` lifetime... LL | self.x.iter().map(|a| a.0) | ------ ^^^^ | | | ...but this borrow... | note: ...can't outlive the anonymous lifetime #1 defined on the method body at 16:5 --> $DIR/static-return-lifetime-infered.rs:16:5 | LL | / fn iter_values_anon(&self) -> impl Iterator<Item=u32> { LL | | self.x.iter().map(|a| a.0) LL | | } | |_____^ help: you can add a constraint to the return type to make it last less than `'static` and match the anonymous lifetime #1 defined on the method body at 16:5 | LL | fn iter_values_anon(&self) -> impl Iterator<Item=u32> + '_ { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ```

@matthewjasper

…-box, r=eddyb [NLL] Dangly paths for box Special-case `Box` in `rustc_mir::borrow_check`. Since we know dropping a box will not access any `&mut` or `&` references, it is safe to model its destructor as only touching the contents *owned* by the box. ---- There are three main things going on here: 1. The first main thing, this PR is fixing a bug in NLL where `rustc` previously would issue a diagnostic error in a case like this: ```rust fn foo(x: Box<&mut i32>) -> &mut i32 { &mut **x } ``` such code was accepted by the AST-borrowck in the past, but NLL was rejecting it with the following message ([playground](https://play.rust-lang.org/?gist=13c5560f73bfb16d6dab3ceaad44c0f8&version=nightly&mode=release&edition=2015)) ``` error[E0597]: `**x` does not live long enough --> src/main.rs:3:40 | 3 | fn foo(x: Box<&mut i32>) -> &mut i32 { &mut **x } | ^^^^^^^^ - `**x` dropped here while still borrowed | | | borrowed value does not live long enough | note: borrowed value must be valid for the anonymous lifetime #1 defined on the function body at 3:1... --> src/main.rs:3:1 | 3 | fn foo(x: Box<&mut i32>) -> &mut i32 { &mut **x } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to previous error ``` 2. The second main thing: The reason such code was previously rejected was because NLL (MIR-borrowck) incorporates a fix for issue rust-lang#31567, where it models a destructor's execution as potentially accessing any borrows held by the thing being destructed. The tests with `Scribble` model this, showing that the compiler now catches such unsoundness. However, that fix for issue rust-lang#31567 is too strong, in that NLL (MIR-borrowck) includes `Box` as one of the types with a destructor that potentially accesses any borrows held by the box. This thus was the cause of the main remaining discrepancy between AST-borrowck and MIR-borrowck, as documented in issue rust-lang#45696, specifically in [the last example of this comment](rust-lang#45696 (comment)), which I have adapted into the `fn foo` shown above. We did close issue rust-lang#45696 back in December of 2017, but AFAICT that example was not fixed by PR rust-lang#46268. (And we did not include a test, etc etc.) This PR fixes that case, by trying to model the so-called `DerefPure` semantics of `Box<T>` when we traverse the type of the input to `visit_terminator_drop`. 3. The third main thing is that during a review of the first draft of this PR, @matthewjasper pointed out that the new traversal of `Box<T>` could cause the compiler to infinite loop. I have adjusted the PR to avoid this (by tracking what types we have previously seen), and added a much needed test of this somewhat odd scenario. (Its an odd scenario because the particular case only arises for things like `struct A(Box<A>);`, something which cannot be constructed in practice.) Fix rust-lang#45696.

fix typos

sync fork with upstream (master)

Explain safety for `vec.set_len(0)`

Merge recent changes into master

update for vxWorks

Pull from newest repo

…ing opaque return type Go from ``` error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements --> file8.rs:22:5 | 22 | / move || { 23 | | *dest = g.get(); 24 | | } | |_____^ | note: first, the lifetime cannot outlive the anonymous lifetime #1 defined on the function body at 18:1... --> file8.rs:18:1 | 18 | / fn bat<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ + 'a 19 | | where 20 | | G: Get<T> 21 | | { ... | 24 | | } 25 | | } | |_^ note: ...so that the types are compatible --> file8.rs:22:5 | 22 | / move || { //~ ERROR cannot infer an appropriate lifetime 23 | | *dest = g.get(); 24 | | } | |_____^ = note: expected `&mut T` found `&mut T` note: but, the lifetime must be valid for the lifetime `'a` as defined on the function body at 18:8... --> file8.rs:18:8 | 18 | fn bat<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ + 'a | ^^ note: ...so that return value is valid for the call --> file8.rs:18:45 | 18 | fn bat<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ + 'a | ^^^^^^^^^^^^^^^^^^^^^^^ ``` to ``` error[E0621]: explicit lifetime required in the type of `dest` --> file8.rs:18:45 | 18 | fn bat<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ + 'a | ------ ^^^^^^^^^^^^^^^^^^^^^^^ lifetime `'a` required | | | help: add explicit lifetime `'a` to the type of `dest`: `&'a mut T` ```

update from upstream

…nt, r=Mark-Simulacrum Show nicer error when an 'unstable fingerprints' error occurs An example of the error produced by this PR: ``` error: internal compiler error: encountered incremental compilation error with evaluate_obligation(9f2ad55260c30262-c36667639674ad83) | = help: This is a known issue with the compiler. Run `cargo clean -p syn` or `cargo clean` to allow your project to compile = note: Please follow the instructions below to create a bug report with the provided information thread 'rustc' panicked at 'Found unstable fingerprints for evaluate_obligation(9f2ad55260c30262-c36667639674ad83): Ok(EvaluatedToOk)', /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:595:9 stack backtrace: 0: rust_begin_unwind at /home/aaron/repos/rust/library/std/src/panicking.rs:493:5 1: std::panicking::begin_panic_fmt at /home/aaron/repos/rust/library/std/src/panicking.rs:435:5 2: rustc_query_system::query::plumbing::incremental_verify_ich at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:595:9 3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:557:9 4: rustc_query_system::query::plumbing::try_execute_query::{{closure}}::{{closure}} at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:473:21 5: core::option::Option<T>::map at /home/aaron/repos/rust/library/core/src/option.rs:487:29 6: rustc_query_system::query::plumbing::try_execute_query::{{closure}} at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:471:13 7: stacker::maybe_grow at /home/aaron/.cargo/registry/src/github.com-1ecc6299db9ec823/stacker-0.1.12/src/lib.rs:55:9 8: rustc_data_structures::stack::ensure_sufficient_stack at /home/aaron/repos/rust/compiler/rustc_data_structures/src/stack.rs:16:5 9: <rustc_query_impl::plumbing::QueryCtxt as rustc_query_system::query::QueryContext>::start_query::{{closure}}::{{closure}} at /home/aaron/repos/rust/compiler/rustc_query_impl/src/plumbing.rs:169:17 10: rustc_middle::ty::context::tls::enter_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1736:50 11: rustc_middle::ty::context::tls::set_tlv at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1720:9 12: rustc_middle::ty::context::tls::enter_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1736:9 13: <rustc_query_impl::plumbing::QueryCtxt as rustc_query_system::query::QueryContext>::start_query::{{closure}} at /home/aaron/repos/rust/compiler/rustc_query_impl/src/plumbing.rs:168:13 14: rustc_middle::ty::context::tls::with_related_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1780:13 15: rustc_middle::ty::context::tls::with_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1764:40 16: rustc_middle::ty::context::tls::with_context_opt at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1753:22 17: rustc_middle::ty::context::tls::with_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1764:9 18: rustc_middle::ty::context::tls::with_related_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1777:9 19: <rustc_query_impl::plumbing::QueryCtxt as rustc_query_system::query::QueryContext>::start_query at /home/aaron/repos/rust/compiler/rustc_query_impl/src/plumbing.rs:157:9 20: rustc_query_system::query::plumbing::try_execute_query at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:469:22 21: rustc_query_system::query::plumbing::get_query_impl at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:674:5 22: rustc_query_system::query::plumbing::get_query at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:785:9 23: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::evaluate_obligation at /home/aaron/repos/rust/compiler/rustc_query_impl/src/plumbing.rs:603:17 24: rustc_middle::ty::query::TyCtxtAt::evaluate_obligation at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/query/mod.rs:204:17 25: rustc_middle::ty::query::<impl rustc_middle::ty::context::TyCtxt>::evaluate_obligation at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/query/mod.rs:185:17 26: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation at /home/aaron/repos/rust/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs:72:9 27: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation_no_overflow at /home/aaron/repos/rust/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs:82:15 28: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt>::predicate_must_hold_modulo_regions at /home/aaron/repos/rust/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs:58:9 29: rustc_trait_selection::traits::type_known_to_meet_bound_modulo_regions at /home/aaron/repos/rust/compiler/rustc_trait_selection/src/traits/mod.rs:146:18 30: rustc_ty_utils::common_traits::is_item_raw::{{closure}} at /home/aaron/repos/rust/compiler/rustc_ty_utils/src/common_traits.rs:33:9 31: rustc_infer::infer::InferCtxtBuilder::enter at /home/aaron/repos/rust/compiler/rustc_infer/src/infer/mod.rs:582:9 32: rustc_ty_utils::common_traits::is_item_raw at /home/aaron/repos/rust/compiler/rustc_ty_utils/src/common_traits.rs:32:5 33: rustc_query_system::query::config::QueryVtable<CTX,K,V>::compute at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/config.rs:44:9 34: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory::{{closure}} at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:544:67 35: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps::{{closure}}::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/dep_graph/mod.rs:77:46 36: rustc_middle::ty::context::tls::enter_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1736:50 37: rustc_middle::ty::context::tls::set_tlv at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1720:9 38: rustc_middle::ty::context::tls::enter_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1736:9 39: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/dep_graph/mod.rs:77:13 40: rustc_middle::ty::context::tls::with_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1764:40 41: rustc_middle::ty::context::tls::with_context_opt at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1753:22 42: rustc_middle::ty::context::tls::with_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1764:9 43: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps at /home/aaron/repos/rust/compiler/rustc_middle/src/dep_graph/mod.rs:74:9 44: rustc_query_system::dep_graph::graph::DepGraph<K>::with_ignore at /home/aaron/repos/rust/compiler/rustc_query_system/src/dep_graph/graph.rs:167:9 45: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:544:22 46: rustc_query_system::query::plumbing::try_execute_query::{{closure}}::{{closure}} at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:473:21 47: core::option::Option<T>::map at /home/aaron/repos/rust/library/core/src/option.rs:487:29 48: rustc_query_system::query::plumbing::try_execute_query::{{closure}} at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:471:13 49: stacker::maybe_grow at /home/aaron/.cargo/registry/src/github.com-1ecc6299db9ec823/stacker-0.1.12/src/lib.rs:55:9 50: rustc_data_structures::stack::ensure_sufficient_stack at /home/aaron/repos/rust/compiler/rustc_data_structures/src/stack.rs:16:5 51: <rustc_query_impl::plumbing::QueryCtxt as rustc_query_system::query::QueryContext>::start_query::{{closure}}::{{closure}} at /home/aaron/repos/rust/compiler/rustc_query_impl/src/plumbing.rs:169:17 52: rustc_middle::ty::context::tls::enter_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1736:50 53: rustc_middle::ty::context::tls::set_tlv at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1720:9 54: rustc_middle::ty::context::tls::enter_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1736:9 55: <rustc_query_impl::plumbing::QueryCtxt as rustc_query_system::query::QueryContext>::start_query::{{closure}} at /home/aaron/repos/rust/compiler/rustc_query_impl/src/plumbing.rs:168:13 56: rustc_middle::ty::context::tls::with_related_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1780:13 57: rustc_middle::ty::context::tls::with_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1764:40 58: rustc_middle::ty::context::tls::with_context_opt at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1753:22 59: rustc_middle::ty::context::tls::with_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1764:9 60: rustc_middle::ty::context::tls::with_related_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1777:9 61: <rustc_query_impl::plumbing::QueryCtxt as rustc_query_system::query::QueryContext>::start_query at /home/aaron/repos/rust/compiler/rustc_query_impl/src/plumbing.rs:157:9 62: rustc_query_system::query::plumbing::try_execute_query at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:469:22 63: rustc_query_system::query::plumbing::get_query_impl at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:674:5 64: rustc_query_system::query::plumbing::get_query at /home/aaron/repos/rust/compiler/rustc_query_system/src/query/plumbing.rs:785:9 65: rustc_middle::ty::query::TyCtxtAt::is_unpin_raw at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/query/mod.rs:204:17 66: rustc_middle::ty::util::<impl rustc_middle::ty::TyS>::is_unpin at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/util.rs:727:38 67: rustc_middle::ty::layout::<impl rustc_target::abi::TyAndLayoutMethods<C> for &rustc_middle::ty::TyS>::pointee_info_at at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/layout.rs:2341:32 68: rustc_target::abi::TyAndLayout<Ty>::pointee_info_at at /home/aaron/repos/rust/compiler/rustc_target/src/abi/mod.rs:1164:9 69: <rustc_target::abi::call::FnAbi<&rustc_middle::ty::TyS> as rustc_middle::ty::layout::FnAbiExt<C>>::new_internal::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/layout.rs:2781:36 70: <rustc_target::abi::call::FnAbi<&rustc_middle::ty::TyS> as rustc_middle::ty::layout::FnAbiExt<C>>::new_internal::{{closure}}::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/layout.rs:2840:17 71: rustc_target::abi::call::ArgAbi<Ty>::new at /home/aaron/repos/rust/compiler/rustc_target/src/abi/call/mod.rs:457:53 72: <rustc_target::abi::call::FnAbi<&rustc_middle::ty::TyS> as rustc_middle::ty::layout::FnAbiExt<C>>::new_internal::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/layout.rs:2838:27 73: <rustc_target::abi::call::FnAbi<&rustc_middle::ty::TyS> as rustc_middle::ty::layout::FnAbiExt<C>>::new_internal::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/layout.rs:2870:32 74: core::iter::adapters::map::map_fold::{{closure}} at /home/aaron/repos/rust/library/core/src/iter/adapters/map.rs:82:28 75: <core::iter::adapters::enumerate::Enumerate<I> as core::iter::traits::iterator::Iterator>::fold::enumerate::{{closure}} at /home/aaron/repos/rust/library/core/src/iter/adapters/enumerate.rs:104:27 76: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut at /home/aaron/repos/rust/library/core/src/ops/function.rs:269:13 77: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut at /home/aaron/repos/rust/library/core/src/ops/function.rs:269:13 78: core::iter::adapters::map::map_fold::{{closure}} at /home/aaron/repos/rust/library/core/src/iter/adapters/map.rs:82:21 79: core::iter::traits::iterator::Iterator::fold at /home/aaron/repos/rust/library/core/src/iter/traits/iterator.rs:2146:21 80: <core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::fold at /home/aaron/repos/rust/library/core/src/iter/adapters/map.rs:122:9 81: <core::iter::adapters::cloned::Cloned<I> as core::iter::traits::iterator::Iterator>::fold at /home/aaron/repos/rust/library/core/src/iter/adapters/cloned.rs:58:9 82: <core::iter::adapters::chain::Chain<A,B> as core::iter::traits::iterator::Iterator>::fold at /home/aaron/repos/rust/library/core/src/iter/adapters/chain.rs:119:19 83: <core::iter::adapters::chain::Chain<A,B> as core::iter::traits::iterator::Iterator>::fold at /home/aaron/repos/rust/library/core/src/iter/adapters/chain.rs:119:19 84: <core::iter::adapters::enumerate::Enumerate<I> as core::iter::traits::iterator::Iterator>::fold at /home/aaron/repos/rust/library/core/src/iter/adapters/enumerate.rs:110:9 85: <core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::fold at /home/aaron/repos/rust/library/core/src/iter/adapters/map.rs:122:9 86: core::iter::traits::iterator::Iterator::for_each at /home/aaron/repos/rust/library/core/src/iter/traits/iterator.rs:776:9 87: <alloc::vec::Vec<T,A> as alloc::vec::spec_extend::SpecExtend<T,I>>::spec_extend at /home/aaron/repos/rust/library/alloc/src/vec/spec_extend.rs:40:17 88: <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter at /home/aaron/repos/rust/library/alloc/src/vec/spec_from_iter_nested.rs:56:9 89: <alloc::vec::Vec<T> as alloc::vec::spec_from_iter::SpecFromIter<T,I>>::from_iter at /home/aaron/repos/rust/library/alloc/src/vec/spec_from_iter.rs:36:9 90: <alloc::vec::Vec<T> as core::iter::traits::collect::FromIterator<T>>::from_iter at /home/aaron/repos/rust/library/alloc/src/vec/mod.rs:2448:9 91: core::iter::traits::iterator::Iterator::collect at /home/aaron/repos/rust/library/core/src/iter/traits/iterator.rs:1788:9 92: <rustc_target::abi::call::FnAbi<&rustc_middle::ty::TyS> as rustc_middle::ty::layout::FnAbiExt<C>>::new_internal at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/layout.rs:2864:19 93: <rustc_target::abi::call::FnAbi<&rustc_middle::ty::TyS> as rustc_middle::ty::layout::FnAbiExt<C>>::of_instance at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/layout.rs:2670:9 94: rustc_codegen_llvm::mono_item::<impl rustc_codegen_ssa::traits::declare::PreDefineMethods for rustc_codegen_llvm::context::CodegenCx>::predefine_fn at /home/aaron/repos/rust/compiler/rustc_codegen_llvm/src/mono_item.rs:57:22 95: <rustc_middle::mir::mono::MonoItem as rustc_codegen_ssa::mono_item::MonoItemExt>::predefine at /home/aaron/repos/rust/compiler/rustc_codegen_ssa/src/mono_item.rs:76:17 96: rustc_codegen_llvm::base::compile_codegen_unit::module_codegen at /home/aaron/repos/rust/compiler/rustc_codegen_llvm/src/base.rs:122:17 97: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl::{{closure}} at /home/aaron/repos/rust/compiler/rustc_query_system/src/dep_graph/graph.rs:235:62 98: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps::{{closure}}::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/dep_graph/mod.rs:77:46 99: rustc_middle::ty::context::tls::enter_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1736:50 100: rustc_middle::ty::context::tls::set_tlv at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1720:9 101: rustc_middle::ty::context::tls::enter_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1736:9 102: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/dep_graph/mod.rs:77:13 103: rustc_middle::ty::context::tls::with_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1764:40 104: rustc_middle::ty::context::tls::with_context_opt at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1753:22 105: rustc_middle::ty::context::tls::with_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1764:9 106: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps at /home/aaron/repos/rust/compiler/rustc_middle/src/dep_graph/mod.rs:74:9 107: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl at /home/aaron/repos/rust/compiler/rustc_query_system/src/dep_graph/graph.rs:235:26 108: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task at /home/aaron/repos/rust/compiler/rustc_query_system/src/dep_graph/graph.rs:205:9 109: rustc_codegen_llvm::base::compile_codegen_unit at /home/aaron/repos/rust/compiler/rustc_codegen_llvm/src/base.rs:103:9 110: <rustc_codegen_llvm::LlvmCodegenBackend as rustc_codegen_ssa::traits::backend::ExtraBackendMethods>::compile_codegen_unit at /home/aaron/repos/rust/compiler/rustc_codegen_llvm/src/lib.rs:109:9 111: rustc_codegen_ssa::base::codegen_crate at /home/aaron/repos/rust/compiler/rustc_codegen_ssa/src/base.rs:655:38 112: <rustc_codegen_llvm::LlvmCodegenBackend as rustc_codegen_ssa::traits::backend::CodegenBackend>::codegen_crate at /home/aaron/repos/rust/compiler/rustc_codegen_llvm/src/lib.rs:270:18 113: rustc_interface::passes::start_codegen::{{closure}} at /home/aaron/repos/rust/compiler/rustc_interface/src/passes.rs:1021:9 114: rustc_data_structures::profiling::VerboseTimingGuard::run at /home/aaron/repos/rust/compiler/rustc_data_structures/src/profiling.rs:573:9 115: rustc_session::utils::<impl rustc_session::session::Session>::time at /home/aaron/repos/rust/compiler/rustc_session/src/utils.rs:16:9 116: rustc_interface::passes::start_codegen at /home/aaron/repos/rust/compiler/rustc_interface/src/passes.rs:1020:19 117: rustc_interface::queries::Queries::ongoing_codegen::{{closure}}::{{closure}} at /home/aaron/repos/rust/compiler/rustc_interface/src/queries.rs:296:20 118: rustc_interface::passes::QueryContext::enter::{{closure}} at /home/aaron/repos/rust/compiler/rustc_interface/src/passes.rs:755:42 119: rustc_middle::ty::context::tls::enter_context::{{closure}} at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1736:50 120: rustc_middle::ty::context::tls::set_tlv at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1720:9 121: rustc_middle::ty::context::tls::enter_context at /home/aaron/repos/rust/compiler/rustc_middle/src/ty/context.rs:1736:9 122: rustc_interface::passes::QueryContext::enter at /home/aaron/repos/rust/compiler/rustc_interface/src/passes.rs:755:9 123: rustc_interface::queries::Queries::ongoing_codegen::{{closure}} at /home/aaron/repos/rust/compiler/rustc_interface/src/queries.rs:287:13 124: rustc_interface::queries::Query<T>::compute at /home/aaron/repos/rust/compiler/rustc_interface/src/queries.rs:40:28 125: rustc_interface::queries::Queries::ongoing_codegen at /home/aaron/repos/rust/compiler/rustc_interface/src/queries.rs:285:9 126: rustc_driver::run_compiler::{{closure}}::{{closure}} at /home/aaron/repos/rust/compiler/rustc_driver/src/lib.rs:442:13 127: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter at /home/aaron/repos/rust/compiler/rustc_interface/src/queries.rs:428:19 128: rustc_driver::run_compiler::{{closure}} at /home/aaron/repos/rust/compiler/rustc_driver/src/lib.rs:337:22 129: rustc_interface::interface::create_compiler_and_run::{{closure}} at /home/aaron/repos/rust/compiler/rustc_interface/src/interface.rs:208:13 130: rustc_span::with_source_map at /home/aaron/repos/rust/compiler/rustc_span/src/lib.rs:788:5 131: rustc_interface::interface::create_compiler_and_run at /home/aaron/repos/rust/compiler/rustc_interface/src/interface.rs:202:5 132: rustc_interface::interface::run_compiler::{{closure}} at /home/aaron/repos/rust/compiler/rustc_interface/src/interface.rs:224:12 133: rustc_interface::util::setup_callbacks_and_run_in_thread_pool_with_globals::{{closure}}::{{closure}} at /home/aaron/repos/rust/compiler/rustc_interface/src/util.rs:155:13 134: scoped_tls::ScopedKey<T>::set at /home/aaron/.cargo/registry/src/github.com-1ecc6299db9ec823/scoped-tls-1.0.0/src/lib.rs:137:9 135: rustc_span::with_session_globals at /home/aaron/repos/rust/compiler/rustc_span/src/lib.rs:105:5 136: rustc_interface::util::setup_callbacks_and_run_in_thread_pool_with_globals::{{closure}} at /home/aaron/repos/rust/compiler/rustc_interface/src/util.rs:153:9 137: rustc_interface::util::scoped_thread::{{closure}} at /home/aaron/repos/rust/compiler/rustc_interface/src/util.rs:128:24 note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace. error: internal compiler error: unexpected panic note: the compiler unexpectedly panicked. this is a bug. note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md note: rustc 1.54.0-dev running on x86_64-unknown-linux-gnu note: compiler flags: -C opt-level=3 -C embed-bitcode=no -C incremental --crate-type lib note: some of the compiler flags provided by cargo are hidden query stack during panic: #0 [evaluate_obligation] evaluating trait selection obligation `quote::Tokens: std::marker::Unpin` #1 [is_unpin_raw] computing whether `quote::Tokens` is `Unpin` end of query stack error: aborting due to previous error error: could not compile `syn` To learn more, run the command again with --verbose. ``` I've left in the panic and ICE following the pretty error, so that we still have all of the debug information available in a bug report. This message can be reproduced by cloning the repository `https://github.com/Aaron1011/syn-crash`, and running the following shell script (with a `rustup override` set in the directory): ``` set -xe cargo clean -p syn cargo clean --release -p syn git checkout minimize cargo build --release -j 1 git checkout minimize-change cargo build --release -j 1 ``` r? ``@Mark-Simulacrum``

Otherwise, we can get into a situation where you have a subtype obligation `#1 <: #2` pending, #1 is constrained by `check_casts`, but #2` is unaffected. Co-authored-by: Niko Matsakis <niko@alum.mit.edu>

author Preston From <prestonfrom@gmail.com> 1645164142 -0600 committer Preston From <prestonfrom@gmail.com> 1650005351 -0600

Jonathan Turner added 2 commits March 31, 2016 17:19

Add support for elision in structured error messages

ae54121

Remove commented out code and reorder for readability

ff2868d

nikomatsakis merged commit c6ab068 into nikomatsakis:borrowck-snippet Apr 1, 2016

nikomatsakis pushed a commit that referenced this pull request May 10, 2016

Merge pull request #1 from nrc/save-ids-fix

192e336

Save ids fix

nikomatsakis pushed a commit that referenced this pull request Feb 27, 2017

Fix tests on Windows (#1)

227eab0

nikomatsakis pushed a commit that referenced this pull request Dec 14, 2017

Merge pull request #1 from solson/fixup-function_pointers2

4ae77b7

Fixup function_pointers2

nikomatsakis pushed a commit that referenced this pull request Apr 19, 2018

Merge pull request #1 from rust-lang/master

5e94d54

Merge upstream changes

nikomatsakis pushed a commit that referenced this pull request Sep 25, 2018

Merge pull request #1 from ubsan/ptr-docs

c44e88c

fix typos

nikomatsakis pushed a commit that referenced this pull request Nov 14, 2018

Merge pull request #1 from rust-lang/master

fa76d42

sync fork with upstream (master)

nikomatsakis pushed a commit that referenced this pull request Jan 22, 2019

Merge pull request #1 from Centril/redo-vec-set_len-docs-adjust

986e49d

Explain safety for `vec.set_len(0)`

nikomatsakis pushed a commit that referenced this pull request Aug 8, 2019

Avoid cloning Place in assign #1

b490032

nikomatsakis pushed a commit that referenced this pull request Aug 12, 2019

Merge pull request #1 from rust-lang/master

fb3a013

Merge recent changes into master

nikomatsakis pushed a commit that referenced this pull request Aug 19, 2019

Merge pull request #1 from Wind-River/vxworks_bpang_static

403e672

update for vxWorks

nikomatsakis pushed a commit that referenced this pull request Aug 27, 2019

Merge pull request #1 from rust-lang/master

92f08b7

Pull from newest repo

nikomatsakis pushed a commit that referenced this pull request Jun 22, 2020

Merge pull request #1 from rust-lang/master

a6127e3

update from upstream

nikomatsakis pushed a commit that referenced this pull request May 27, 2022

Lint for significant drops who may have surprising lifetimes #1

d9e963f

author Preston From <prestonfrom@gmail.com> 1645164142 -0600 committer Preston From <prestonfrom@gmail.com> 1650005351 -0600

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Add support for elision in structured error messages #1

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Add support for elision in structured error messages #1

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