Inline Assembly cause segmentation fault when define label.

[iseki-masaya]

OS: OS X 10.8.5
Architecture: x86_64

$ rustc -v
rustc 0.11.0-pre-nightly (6291955 2014-05-19 23:41:20 -0700)
host: x86_64-apple-darwin

fn main() {
    unsafe {
        asm!("label:");
    }
}

This code pass the compiler but cause segmentation fault.
Inline Assembly in LLVM is called at https://github.com/mozilla/rust/blob/master/src/rustllvm/RustWrapper.cpp#l173
The description of module level inline assembly about LLVM is here(http://llvm.org/docs/LangRef.html#module-level-inline-assembly)

[iseki-masaya]

LLDB says EXC_BAD_ACCESS (code=EXC_I386_GPFLT) and this segmentation fault is not caused on x86_64 linux.

[alexcrichton]

This appears to have been fixed in more recent versions of LLVM (and the currently bundled one)

[ghost]

@alexcrichton This doesn't seem to be fixed on OS X, or at least it's happening again. Using labels seems to cause SIGILL or SIGSEGV. Seems to be the same thing noted here.

[alexcrichton]

Aha I missed the OSX part of this!

[steveklabnik]

Triage: a year and a half later, I'm not sure if this is fixed, as I don't have a mac. We've upgraded LLVM a number of times....

[Mark-Simulacrum]

Verified as still broken today.

[Mark-Simulacrum]

Appears to be fixed today... E-needstest.

[Mark-Simulacrum]

This isn't actually fixed.

[steveklabnik]

Triage: don't have a mac, so I can't reproduce, but that doesn't mean that it has been fixed.

[Dylan-DPC-zz]

I can reproduce this bug. Still exists

[stevecheckoway]

See #63977 (comment)

[Amanieu]

You should only use local labels in inline assembly. This is stated in the documentation for the new asm! macro.