LLVM assertion "Ptr must be a pointer to Val type!" failed.

[ILyoan]

Compiling this code yield LLVM assertion "Ptr must be a pointer to Val type!"

pub mod Bar {
    pub struct Foo {
        v: int,
    }

    extern {
        #[rust_stack]
        pub fn foo(v: *Foo) -> Foo;
    }
}

fn main() { }

rustc: /home/ilyoan/project/rust/rust/src/llvm/lib/IR/Instructions.cpp:1084: void llvm::StoreInst::AssertOK(): Assertion `getOperand(0)->getType() == cast(getOperand(1)->getType())->getElementType() && "Ptr must be a pointer to Val type!"' failed.

[ILyoan]

#4653, #4760 and #6390 produce the same error message, but I'm not sure if those are the same issue.

[catamorphism]

Reproduced 93c270c -- nominating for milestone 5, production-ready

[catamorphism]

Note that #4653, #4760, and #6390 are all fixed, so this is a different bug (this is a common error message with many different causes).

[graydon]

Reproduced. Slight minimization: if you switch the return value to a *Foo it gets through translation. So I think it's just the unhandled combination of #[rust_stack], extern and return-by-structure.

[catamorphism]

0266172 added a test (run-pass/issue-6470.rs)

[catamorphism]

accepted for production-ready

[nikomatsakis]

I am a bit surprised this doesn't work; it will probably depend on the specific ABI we test

[alexcrichton]

This code now compiles, looks like the test just needs to be un-xfail'd. Flagging as needstest