ICE with unannotated literals

[r10r]

[ruben@MacBook-Pro src]$ rustc --version=verbose
rustc 0.13.0-nightly (40fb87d40 2014-11-10 23:01:57 +0000)
binary: rustc
commit-hash: 40fb87d40f681f5356af42175fc7b85da387f037
commit-date: 2014-11-10 23:01:57 +0000
host: x86_64-apple-darwin
release: 0.13.0-nightly

trait Adder<Number> {
  fn sum(&self, summands: &[Number]) -> Number;
}

struct Calculator {
  foo: int,
}

impl Adder<int> for Calculator {

  fn sum(&self, summands: &[int]) -> int {
    println!("sum int");
    let mut result = 0i;
    for num in summands.iter() {
      result += *num;
    }
    result
  }
}

impl Adder<f32> for Calculator {

  fn sum(&self, summands: &[f32]) -> f32 {
    println!("sum f32");
    let mut result = 0f32;
    for num in summands.iter() {
      result += *num;
    }
    result
  }
}


fn main() {
  let calc = Calculator { foo: 4711 };
  println!("1 + 1 = {}", calc.sum([1,1].as_slice()));

  // raises the compiler error
  println!("1.0 + 2.3 = {}", calc.sum([1.0,2.3].as_slice()));
  // compiles and runs properly
  //println!("1.0 + 2.3 = {}", calc.sum([1.0f32,2.3f32].as_slice()));
}

error: internal compiler error: Impl DefId { krate: 0, node: 26 }:Calculator.Adder<int> was matchable against Obligation(trait_ref=<_ : Adder<_>>,depth=0) but now is not
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' panicked at 'Box<Any>', /Users/rustbuild/src/rust-buildbot/slave/nightly-mac/build/src/libsyntax/diagnostic.rs:175

stack backtrace:
   1:        0x11011e01f - rt::backtrace::imp::write::h37f6e30fade15cb76mt
   2:        0x1101211a7 - failure::on_fail::h4075de659ea4adb9VDt
   3:        0x1103a4415 - unwind::begin_unwind_inner::h9e12d6856ac2af42j1c
   4:        0x10e086757 - unwind::begin_unwind::h887212781071489879
   5:        0x10e086f93 - diagnostic::Handler::bug::he58e2d0573e8d5d4L5F
   6:        0x10d105271 - middle::traits::select::SelectionContext<'cx, 'tcx>::rematch_impl::h35320cfc53204d2fFbZ
   7:        0x10d0f3607 - middle::traits::select::SelectionContext<'cx, 'tcx>::confirm_candidate::hb7278faaf8bd08bdDRY
   8:        0x10d0ea1b7 - middle::traits::select::SelectionContext<'cx, 'tcx>::select::h20d24e63da941032znX
   9:        0x10d0e8e86 - middle::traits::fulfill::FulfillmentContext::select::h4f9eb03bbb3d4aa6gUW
  10:        0x10d0e8656 - middle::traits::fulfill::FulfillmentContext::select_where_possible::h212cad5c41e6ff5evTW
  11:        0x10d0014d2 - middle::traits::fulfill::FulfillmentContext::select_all_or_error::ha09a57d720916db7iRW
  12:        0x10d26dc78 - middle::typeck::check::vtable::select_all_fcx_obligations_or_error::h4291cb6f90f0ee15K7N
  13:        0x10d2c5ccb - middle::typeck::check::check_bare_fn::hec13c0cf792a848da8V
  14:        0x10d2c1e1d - middle::typeck::check::check_item::h7dd222d42ec19845jsW
  15:        0x10d2c5b10 - middle::typeck::check::check_item_types::hdbb49e408a7799c1k7V
  16:        0x10cdd1156 - util::common::time::h3942551398258420223
  17:        0x10d5d1eee - middle::typeck::check_crate::hcb0ab152bef1200chup
  18:        0x10d639d9f - driver::driver::phase_3_run_analysis_passes::hc02fc7265031485eIdC
  19:        0x10d634bd8 - driver::driver::compile_input::h2ba3685ec9df4f6btUB
  20:        0x10d6b23ed - driver::run_compiler::h6e93cd8bbb72fd50KKF
  21:        0x10d6b092e - driver::run::closure.146334
  22:        0x10cde940b - task::TaskBuilder<S>::try_future::closure.104770
  23:        0x10cde9303 - task::TaskBuilder<S>::spawn_internal::closure.104741
  24:        0x10cda27bd - task::NativeSpawner.Spawner::spawn::closure.2551
  25:        0x110402a0c - rust_try_inner
  26:        0x1104029f6 - rust_try
  27:        0x1103a1be7 - unwind::try::h009a35089a5882701Pc
  28:        0x1103a1a7c - task::Task::run::h4878cb7b665069bf61b
  29:        0x10cda25e3 - task::NativeSpawner.Spawner::spawn::closure.2475
  30:        0x1103a32a7 - thread::thread_start::h8e83ad43ae75daab3mc
  31:     0x7fff914642fc - _pthread_body
  32:     0x7fff91464279 - _pthread_body

[yuriks]

rustc 0.13.0-nightly (d91a015ab 2014-11-14 23:37:27 +0000)
Here's another testcase for this bug:

trait Num {}

impl Num for i32 {}
impl Num for f32 {}

fn vec2s<T: Num>(a: T) {}

fn main() {
    // Removing either of these lines, or explicitly typing one of the literals stops the ICE from happening
    vec2s(0.0);
    vec2s(0);
}

error: internal compiler error: Impl DefId { krate: 0, node: 12 }:f32.Num was matchable against Obligation(trait_ref=<_ : Num>,depth=0) but now is not
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' panicked at 'Box<Any>', /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/libsyntax/diagnostic.rs:175

stack backtrace:
   1:     0x7f915ce993e0 - rt::backtrace::imp::write::h50b71c7573aa44d5Bgt
   2:     0x7f915ce9c460 - failure::on_fail::hc49a9332645beb08cCt
   3:     0x7f915d650c60 - unwind::begin_unwind_inner::hfe5348fa0e613e77E9c
   4:     0x7f915bdefa40 - unwind::begin_unwind::h2013521801281920279
   5:     0x7f915bdf01e0 - diagnostic::Handler::bug::h5ffb209701b06176C5F
   6:     0x7f915dd81300 - middle::traits::select::SelectionContext<'cx, 'tcx>::rematch_impl::h2e796c80b6b7b2d1RbZ
   7:     0x7f915dd6e380 - middle::traits::select::SelectionContext<'cx, 'tcx>::confirm_candidate::hcd9eb474da2b9af3PRY
   8:     0x7f915dd652c0 - middle::traits::select::SelectionContext<'cx, 'tcx>::select::hc07798a8a63189c7LnX
   9:     0x7f915dd63f30 - middle::traits::fulfill::FulfillmentContext::select::h38f1482e9e3d7175sUW
  10:     0x7f915deec9b0 - middle::typeck::check::vtable::select_new_fcx_obligations::h14c7bd91cbe892c8elO
  11:     0x7f915df81820 - middle::typeck::check::check_argument_types::h6b677199ffbdfaa2w4Y
  12:     0x7f915df83230 - middle::typeck::check::check_expr_with_unifier::h3fbf149ddd449935CDZ
  13:     0x7f915dfdcd30 - middle::typeck::check::check_stmt::h697d8a2a54580689zK1
  14:     0x7f915df47e50 - middle::typeck::check::check_block_with_expected::h4705ff96e614d629IO1
  15:     0x7f915df448e0 - middle::typeck::check::check_fn::he598dd4226ca32f92fW
  16:     0x7f915df44620 - middle::typeck::check::check_bare_fn::ha7a99d35a2a226a0h5V
  17:     0x7f915df40730 - middle::typeck::check::check_item::h6dc4c4f79498f002qpW
  18:     0x7f915df443e0 - middle::typeck::check::check_item_types::hae2bcc56566542e1r4V
  19:     0x7f915da3a4d0 - util::common::time::h9758243045951098006
  20:     0x7f915e2682d0 - middle::typeck::check_crate::he3aeb73f13b2d5c7lrp
  21:     0x7f915e2d0940 - driver::driver::phase_3_run_analysis_passes::h2dd06c2b56df9fc3M9B
  22:     0x7f915e2cb7d0 - driver::driver::compile_input::h0eb7d13e493860ffxQB
  23:     0x7f915e352fd0 - driver::run_compiler::hfef7578eee798d05OGF
  24:     0x7f915e352ec0 - driver::run::closure.146242
  25:     0x7f915da53d70 - task::TaskBuilder<S>::try_future::closure.104747
  26:     0x7f915da53b60 - task::TaskBuilder<S>::spawn_internal::closure.104718
  27:     0x7f915ebacb00 - task::NativeSpawner.Spawner::spawn::closure.2456
  28:     0x7f915d6a5bc0 - rust_try_inner
  29:     0x7f915d6a5bb0 - rust_try
  30:     0x7f915d64e5e0 - unwind::try::he984010f47153659mYc
  31:     0x7f915d64e470 - task::Task::run::had29636eca7af1a3u4b
  32:     0x7f915ebac840 - task::NativeSpawner.Spawner::spawn::closure.2382
  33:     0x7f915d64fc80 - thread::thread_start::h1833ce4dca7b1a7erpc
  34:     0x7f915868f250 - start_thread
  35:     0x7f915d32a3b9 - clone
  36:                0x0 - <unknown>

[yuriks]

It seems this bug is specifically triggered by using untyped literals, so perhaps the issue title should be changed.

[steveklabnik]

can confirm this is still present in rustc 1.0.0-nightly (07560d233 2015-04-20) (built 2015-04-20)

[arielb1]

Yet another duplicate of #24352.

[alexcrichton]

Thanks for finding all these duplicates @arielb1!