ICE when trying to assign to unsafe pointer

[toffaletti]

use std::ptr::{mut_null, to_mut_unsafe_ptr};

struct Foo {
    priv data: *mut Foo,
}

impl Foo {
    fn get_foo(&mut self) -> *mut Foo {
        self.data
    }
}

fn main() {
    let mut f = Foo{data: mut_null()};
    f.get_foo() = to_mut_unsafe_ptr(&mut f);
}

$ rustc ice.rs 
ice.rs:15:4: 15:17 error: internal compiler error: trans_lvalue reached fall-through case: ExprMethodCall(33, @syntax::ast::Expr{id: 34, node: ExprPath(syntax::ast::Path{span: syntax::codemap::Span{lo: syntax::codemap::BytePos(220u), hi: syntax::codemap::BytePos(221u), expn_info: None}, global: false, segments: ~[syntax::ast::PathSegment{identifier: syntax::ast::Ident{name: 78u, ctxt: 29u}, lifetime: None, types: Empty}]}), span: syntax::codemap::Span{lo: syntax::codemap::BytePos(220u), hi: syntax::codemap::BytePos(221u), expn_info: None}}, syntax::ast::Ident{name: 77u, ctxt: 29u}, ~[], ~[], NoSugar)
ice.rs:15     f.get_foo() = to_mut_unsafe_ptr(&mut f);

[bmaxa]

I think this is not related to unsafe pointer,rather to assigning to a value, eg return anything
not assignable and you will get ICE.

[alexcrichton]

It appears that @bmaxa is correct, this code also ICEs

fn foo() -> int { 3 }

fn main() {          
    foo() = 3;       
}                    

It appears the typechecker ensures that the lhs and rhs have the same type, but not that the lhs is actually an assignable location...

[alexcrichton]

cc @nikomatsakis

[klutzy]

Seems like dup of #7507.

[toffaletti]

Agreed.