LLVM error when optimizations are turned off #1

dylanmckay · 2014-11-11T12:01:32Z

When using rustc to compile for the AVR target, an LLVM error is generated:

LLVM ERROR: regalloc=... not currently supported with -O0

Which can be tracked back to llvm/lib/CodeGen/LiveVariables.cpp:635. There is a note at this line mentioning that this bug is an artifact of 'bizarre pass dependencies' and that it should be fixed. This leads me to believe that this error can be solved by either writing the fix specified on the aforementioned line, or simply changing the order in which Rust adds LLVM passes.

The AVR LLVM backend can successfully generate executables on its own (using llc), and so this bug must lay in Rust itself.

The text was updated successfully, but these errors were encountered:

dylanmckay · 2014-11-11T12:08:21Z

The issue can be fixed by changing the optimisation level. This error will occur when compiling an AVR target with no optimisations (the default), but passing the -O' or--opt-level=2` flags will lead to a successful compilation.

Update from original

dylanmckay · 2015-04-05T02:56:37Z

The issue is described in avr-llvm/llvm issue #15, and has now been fixed.

The bug no longer persists in avr-rust because we updated LLVM.

fix double "however"

Save ids fix

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.

…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` ```

dylanmckay changed the title ~~AVR compilation~~ LLVM error when optimizations are turned off Nov 12, 2014

dylanmckay mentioned this issue Nov 12, 2014

Link error in stage1 #2

Closed

dylanmckay pushed a commit that referenced this issue Nov 25, 2014

Merge pull request #1 from rust-lang/master

46bdb45

Update from original

dylanmckay added the bug label Nov 25, 2014

This was referenced Nov 25, 2014

Register access is optimised away #7

Closed

Support different target features avr-llvm/llvm#9

Closed

Compilation failure if optimisations are turned off avr-llvm/llvm#15

Closed

dylanmckay closed this as completed Apr 5, 2015

dylanmckay pushed a commit that referenced this issue Aug 11, 2015

Merge pull request #1 from Manishearth/patch-1

9997a6e

fix double "however"

shepmaster pushed a commit that referenced this issue May 31, 2016

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

192e336

Save ids fix

shepmaster pushed a commit that referenced this issue Apr 19, 2017

Fix tests on Windows (#1)

227eab0

carlos4242 mentioned this issue Jun 2, 2017

Indirect call address is possibly being loaded incorrectly #65

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dylanmckay mentioned this issue Aug 23, 2017

Assertion failed: (!SplitVirtReg->empty() && "expecting non-empty interval"), function allocatePhysRegs #36

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carlos4242 mentioned this issue Oct 22, 2017

The order of assembly code output from attached IL is broken when optimisation is O1 or greater #83

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dylanmckay mentioned this issue Mar 7, 2018

[LLVM 6.0] core::fmt::Debug implementations causing 'error: ran out of registers' #95

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LLVM error when optimizations are turned off #1

LLVM error when optimizations are turned off #1

dylanmckay commented Nov 11, 2014

dylanmckay commented Nov 11, 2014

dylanmckay commented Apr 5, 2015

LLVM error when optimizations are turned off #1

LLVM error when optimizations are turned off #1

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dylanmckay commented Nov 11, 2014

dylanmckay commented Nov 11, 2014

dylanmckay commented Apr 5, 2015