Unexpected non-scalars in outputs of `asm!` cause rustc to dump core

[cbiffle]

Unexpected non-scalars in outputs of asm! cause rustc to dump core. (Doing this inputs causes a different problem; see #37433).

To reproduce:

#![feature(asm)]

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

I get:

rustc: /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/src/llvm/lib/IR/InlineAsm.cpp:46: llvm::InlineAsm::InlineAsm(llvm::FunctionType*, const string&, const string&, bool, bool, llvm::InlineAsm::AsmDialect): Assertion `Verify(getFunctionType(), constraints) && "Function type not legal for constraints!"' failed.
Aborted (core dumped)

Meta

rustc --version --verbose:
rustc 1.14.0-nightly (c59cb71 2016-10-26)
binary: rustc
commit-hash: c59cb71
commit-date: 2016-10-26
host: x86_64-unknown-linux-gnu
release: 1.14.0-nightly
LLVM version: 3.9

No backtrace was produced (core dumped).

[arielb1]

This is an LLVM assertion:

rustc: /home/ariel/Rust/rust-master/src/llvm/lib/IR/InlineAsm.cpp:46: llvm::InlineAsm::InlineAsm(llvm::FunctionType*, const string&, const string&, bool, bool, llvm::InlineAsm::AsmDialect): Assertion `Verify(getFunctionType(), constraints) && "Function type not legal for constraints!"' failed.
Aborted

[levex]

No longer reproduces on nightly: https://play.rust-lang.org/?gist=ff40c68f35055c97aaa471149cc23e37&version=nightly&mode=debug&edition=2015

(Fixed by PR #54568)

[Amanieu]

This issue does not apply to the new asm! (RFC 2850) which has stricter checks on the types that can be used as asm operands.

The legacy llvm_asm! is deprecated and is no longer maintained.