Reordering type parameters bounds in trait vs impl causes ICE during trans

[nikomatsakis]

The following test causes an ICE in trans:

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// Tests that everything still compiles and runs fine even when
// we reorder the bounds.

trait A {
    fn a(&self) -> uint;
}

trait B {
    fn b(&self) -> uint;
}

trait C {
    fn combine<T:A+B>(&self, t: &T) -> uint;
}

struct Foo;

impl A for Foo {
    fn a(&self) -> uint { 1 }
}

impl B for Foo {
    fn b(&self) -> uint { 2 }
}

struct Bar;

impl C for Bar {
    // Note below: bounds in impl decl are in reverse order.
    fn combine<T:B+A>(&self, t: &T) -> uint {
        (t.a() * 100) + t.b()
    }
}

fn use_c<S:C, T:B+A>(s: &S, t: &T) -> uint {
    s.combine(t)
}

fn main() {
    let foo = Foo;
    let bar = Bar;
    let r = use_c(&bar, &foo);
    assert_eq!(r, 102);
}

[emberian]

What a silly bug! Backtrace:

[16:36:30]/tmp> RUST_LOG=rustc=1,::rt::backtrace rustc foo.rs 
rust: task failed at 'could not find method while translating', /home/cmr/hacking/rust/src/libstd/option.rs:307
/home/cmr/.local/bin/../lib/librustrt.so(+0x1aacd)[0x7f47e3776acd]
/home/cmr/.local/bin/../lib/librustrt.so(+0x1b7c9)[0x7f47e37777c9]
/home/cmr/.local/bin/../lib/librustrt.so(+0x2bb45)[0x7f47e3787b45]
/home/cmr/.local/bin/../lib/librustrt.so(_ZN9rust_task15call_on_c_stackEPvS0_+0xc3)[0x7f47e3778573]
/home/cmr/.local/bin/../lib/librustrt.so(upcall_fail+0xa8)[0x7f47e3778fd8]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(_ZN3sys13begin_unwind_16_89e154cd09156713_07E+0x3cc)[0x7f47e51e3eac]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0xfaad2)[0x7f47e51e3ad2]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0xfaa01)[0x7f47e51e3a01]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0xfaa8c)[0x7f47e51e3a8c]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0xfaa01)[0x7f47e51e3a01]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(_ZN3sys14__extensions__10meth_100689fail_with17_d96679812a86c3673_07E+0x7b)[0x7f47e514df1b]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4meth27method_with_name_or_default17_586b8c59672e62f03_07E+0x1171)[0x7f47e3c4b661]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4meth26trans_monomorphized_callee17_284f2277bb6b9a303_07E+0x2e5)[0x7f47e3c4bdc5]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4meth19trans_method_callee16_f3a28ef97c4b0fd3_07E+0x1382)[0x7f47e3b547b2]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x1a98d8)[0x7f47e3b528d8]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x1bc271)[0x7f47e3b65271]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base10with_scope16_d9e61de1d578ab63_07E+0x426)[0x7f47e3b18176]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee16trans_call_inner17_9a834a73d699b4b03_07E+0x119)[0x7f47e3b51639]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee17trans_method_call16_2b4bb88edf82b763_07E+0x69c)[0x7f47e3b51dec]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr27trans_rvalue_dps_unadjusted17_6aa5384cec43b96a3_07E+0x694)[0x7f47e3b74e24]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr25trans_to_datum_unadjusted16_637a329f6de24423_07E+0x72e)[0x7f47e3b6c47e]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr14trans_to_datum16_637a329f6de24423_07E+0x1d1)[0x7f47e3b0fee1]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr12trans_binary16_cb549c773a7ffc23_07E+0x12a)[0x7f47e3b7b78a]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr29trans_rvalue_datum_unadjusted16_637a329f6de24423_07E+0xa24)[0x7f47e3b73d44]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr29trans_rvalue_datum_unadjusted16_637a329f6de24423_07E+0x3a7)[0x7f47e3b736c7]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr25trans_to_datum_unadjusted16_637a329f6de24423_07E+0x407)[0x7f47e3b6c157]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr14trans_to_datum16_637a329f6de24423_07E+0x1d1)[0x7f47e3b0fee1]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr12trans_binary16_cb549c773a7ffc23_07E+0x12a)[0x7f47e3b7b78a]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr29trans_rvalue_datum_unadjusted16_637a329f6de24423_07E+0xa24)[0x7f47e3b73d44]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr10trans_into17_6aa5384cec43b96a3_07E+0x8f9)[0x7f47e3b0d209]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans11controlflow11trans_block16_a1a3d8a7623fa0c3_07E+0x265)[0x7f47e3b09d45]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base13trans_closure17_b8db6d925d34efc33_07E+0x90c)[0x7f47e3c0af7c]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base8trans_fn17_c81fea88312b9e293_07E+0x452)[0x7f47e3acdde2]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4meth12trans_method17_4928db1bbbbde6fa3_07E+0x234)[0x7f47e3b02aa4]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans12monomorphize14monomorphic_fn17_1e195717afcc97653_07E+0x3724)[0x7f47e3ad1b64]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee25trans_fn_ref_with_vtables16_bbb222c1e45d8583_07E+0x1e95)[0x7f47e3b4c0a5]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4meth26trans_monomorphized_callee17_284f2277bb6b9a303_07E+0x582)[0x7f47e3c4c062]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4meth19trans_method_callee16_f3a28ef97c4b0fd3_07E+0x1382)[0x7f47e3b547b2]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x1a98d8)[0x7f47e3b528d8]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x1bc271)[0x7f47e3b65271]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base10with_scope16_d9e61de1d578ab63_07E+0x426)[0x7f47e3b18176]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee16trans_call_inner17_9a834a73d699b4b03_07E+0x119)[0x7f47e3b51639]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee17trans_method_call16_2b4bb88edf82b763_07E+0x69c)[0x7f47e3b51dec]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr27trans_rvalue_dps_unadjusted17_6aa5384cec43b96a3_07E+0x694)[0x7f47e3b74e24]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr10trans_into17_6aa5384cec43b96a3_07E+0x864)[0x7f47e3b0d174]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans11controlflow11trans_block16_a1a3d8a7623fa0c3_07E+0x265)[0x7f47e3b09d45]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base13trans_closure17_b8db6d925d34efc33_07E+0x90c)[0x7f47e3c0af7c]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base8trans_fn17_c81fea88312b9e293_07E+0x452)[0x7f47e3acdde2]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans12monomorphize14monomorphic_fn17_1e195717afcc97653_07E+0x2178)[0x7f47e3ad05b8]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee25trans_fn_ref_with_vtables16_bbb222c1e45d8583_07E+0x1e95)[0x7f47e3b4c0a5]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee12trans_fn_ref16_8aacd8dad6533683_07E+0x638)[0x7f47e3b45cc8]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee5trans9trans_def17_1564f81c20c381583_07E+0x15f)[0x7f47e3b4444f]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee5trans16_b2108e8dda6cee33_07E+0x34e)[0x7f47e3b43dfe]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x1a8701)[0x7f47e3b51701]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x1bc271)[0x7f47e3b65271]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base10with_scope16_d9e61de1d578ab63_07E+0x426)[0x7f47e3b18176]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee16trans_call_inner17_9a834a73d699b4b03_07E+0x119)[0x7f47e3b51639]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans6callee10trans_call17_5ece37fa7d438db63_07E+0x32b)[0x7f47e3b512db]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr27trans_rvalue_dps_unadjusted17_6aa5384cec43b96a3_07E+0x615)[0x7f47e3b74da5]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4expr10trans_into17_6aa5384cec43b96a3_07E+0x864)[0x7f47e3b0d174]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base10init_local16_daf992f2bcbfbc43_07E+0x5ad)[0x7f47e3c02bbd]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base10trans_stmt17_3ab12d54e9382a393_07E+0x608)[0x7f47e3b0c258]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans11controlflow11trans_block16_a1a3d8a7623fa0c3_07E+0x156)[0x7f47e3b09c36]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base13trans_closure17_b8db6d925d34efc33_07E+0x6f2)[0x7f47e3c0ad62]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base8trans_fn17_c81fea88312b9e293_07E+0x452)[0x7f47e3acdde2]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base10trans_item17_abfeb2c733807abd3_07E+0xa78)[0x7f47e3ac6df8]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base9trans_mod16_d54da25032113143_07E+0x8d)[0x7f47e3c0eb2d]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6middle5trans4base11trans_crate15_56f0fc14e447483_07E+0x469)[0x7f47e3c1d669]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x7a91ad)[0x7f47e41521ad]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6driver6driver12compile_rest16_a7e075f89b93d633_07E+0x24d5)[0x7f47e414fed5]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x7dad74)[0x7f47e4183d74]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6driver6driver12compile_upto17_c68c1e2085f3205e3_07E+0x13c)[0x7f47e41524dc]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN6driver6driver13compile_input17_8fb49a3d65db4a823_07E+0xd5)[0x7f47e4152875]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN12run_compiler17_7449a6c8ce5854633_07E+0x1b13)[0x7f47e4171cb3]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x7daa9e)[0x7f47e4183a9e]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x7d8547)[0x7f47e4181547]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x7cfe5b)[0x7f47e4178e5b]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x7dad74)[0x7f47e4183d74]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0xcd961)[0x7f47e51b6961]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0x143d6c)[0x7f47e522cd6c]
/home/cmr/.local/bin/../lib/librustrt.so(_Z18task_start_wrapperP10spawn_args+0x23)[0x7f47e3776e43]
error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. this is a bug
note: try running with RUST_LOG=rustc=1,::rt::backtrace to get further details and report the results to github.com/mozilla/rust/issues
rust: task failed at 'explicit failure', /home/cmr/hacking/rust/src/librustc/rustc.rs:354
/home/cmr/.local/bin/../lib/librustrt.so(+0x1aacd)[0x7f47e3776acd]
/home/cmr/.local/bin/../lib/librustrt.so(+0x1b7c9)[0x7f47e37777c9]
/home/cmr/.local/bin/../lib/librustrt.so(+0x2bb45)[0x7f47e3787b45]
/home/cmr/.local/bin/../lib/librustrt.so(_ZN9rust_task15call_on_c_stackEPvS0_+0xc3)[0x7f47e3778573]
/home/cmr/.local/bin/../lib/librustrt.so(upcall_fail+0xa8)[0x7f47e3778fd8]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(_ZN3sys13begin_unwind_16_89e154cd09156713_07E+0x3cc)[0x7f47e51e3eac]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0xfb032)[0x7f47e51e4032]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0xfaa01)[0x7f47e51e3a01]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0xfafec)[0x7f47e51e3fec]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0xfaa01)[0x7f47e51e3a01]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0x79d64)[0x7f47e5162d64]
/home/cmr/.local/bin/../lib/libstd-6c65cf4b443341b1-0.7.so(+0x143d6c)[0x7f47e522cd6c]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN7monitor17_bd33c0a4efdb3aac3_07E+0x2295)[0x7f47e4174b95]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(+0x7dad74)[0x7f47e4183d74]
/home/cmr/.local/bin/../lib/librustc-d3cb8c2ccd84a7a7-0.7.so(_ZN4main15_f3d16eaf7d57383_07E+0x87)[0x7f47e41839c7]
/home/cmr/.local/bin/../lib/librustrt.so(_Z18task_start_wrapperP10spawn_args+0x23)[0x7f47e3776e43]
rust: domain main @0x1d19030 root task failed
leaked memory in rust main loop (1 objects)
rustc: ../src/rt/memory_region.cpp:192: memory_region::~memory_region(): Assertion `false' failed.
zsh: abort (core dumped)  RUST_LOG=rustc=1,::rt::backtrace rustc foo.rs

[catamorphism]

Still fails with the same ICE as of b477f7a . Doesn't seem like a release blocker, though.