trait that omits & on self type signals LLVM assertion failure

[jbclements]

Compiling this program:

trait BogusTrait {
  fn its1(self) -> int;
}

impl BogusTrait for int {
  fn its1(self) -> int {1}
}

#[test] fn t1 () {assert! ((13).its1() == 1);}

produces this error message:

% ./x86_64-apple-darwin/stage2/bin/rustc --test /tmp/bug4.rs
Assertion failed: (S->getType()->isPtrOrPtrVectorTy() && "Invalid cast"), function CreatePointerCast, file /Users/fklock/Dev/Mozilla/rust.git/src/llvm/lib/IR/Instructions.cpp, line 2394.
Abort trap: 6

(Original bug report follows)

Compiling this program:

trait BogusTrait {
  fn its1(self) -> int;
}

impl int: BogusTrait {
  fn its1(self) -> int {1}
}

#[test] fn t1 () {assert 13.its1() == 1;}

Produces this error message:

jclements-09740:rust-experimenting clements$ rustc --test trait-testing.rs
Assertion failed: (S->getType()->isPointerTy() && "Invalid cast"), function CreatePointerCast, file /Users/clements/rust/src/llvm/lib/VMCore/Instructions.cpp, line 2383.
Abort trap: 6

[pnkfelix]

I just ran into this. I don't think your trait is bogus, just in case that was implied by its name; by-value Self is part of the language (see #5086). (Though the fact that we assert-fail obviously is bogus.)

[nikomatsakis]

I agree, nothing bogus about this, just a bug.

[nikomatsakis]

Not critical for 0.6; de-milestoning

[jdm]

Probably the same problem as #5321.

[pnkfelix]

I believe I just ran into this again (while attempting to double-check if the ICE for Issue #4776 has indeed gone away), though the assertion error message has changed slightly.

% cat /tmp/bug2.rs
trait Op<T> { fn call(self, T, T) -> T; }

impl<T> Op<T> for int   { fn call(self,  x:T, _y:T) -> T { x } }
impl<T> Op<T> for float { fn call(self, _x:T,  y:T) -> T { y } }

fn main() {
    let a : int   = 3i;
    let b : float = 4f;
    io::println(fmt!("a: %d", a.call(4,5)));
    io::println(fmt!("b: %d", b.call(4,5)));
}
% ./x86_64-apple-darwin/stage2/bin/rustc /tmp/bug2.rs
Assertion failed: (S->getType()->isPtrOrPtrVectorTy() && "Invalid cast"), function CreatePointerCast, file /Users/fklock/Dev/Mozilla/rust.git/src/llvm/lib/IR/Instructions.cpp, line 2394.
Abort trap: 6

(yes, actually, by porting John's original test forward to modernized syntax, I confirmed that the error message has changed on the LLVM side, it seems).