ICE: Unexpected non-scalars in register inputs of `asm!`

[cbiffle]

Unexpected non-scalars in register inputs of asm! can ICE the compiler.

To reproduce:

#![feature(asm)]

fn main() {
    unsafe {
        asm!("" :: "r"(""));
    }
}

This mistake goes uncaught until it reaches this line of code where it bug!s. I would expect it to have been caught earlier, during asm! argument validation.

I've found a similar case which dumps core, which will be the subject of a separate bug.

Meta

rustc --version --verbose:
rustc 1.14.0-nightly (c59cb71 2016-10-26)
binary: rustc
commit-hash: c59cb71
commit-date: 2016-10-26
host: x86_64-unknown-linux-gnu
release: 1.14.0-nightly
LLVM version: 3.9

Backtrace:

thread 'rustc' panicked at 'Box<Any>', ../src/librustc_errors/lib.rs:655
stack backtrace:
   1:     0x7eff0357f908 - std::sys::backtrace::tracing::imp::write::h22f199c1dbb72ba2
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:42
   2:     0x7eff0358efbf - std::panicking::default_hook::{{closure}}::h9a389c462b6a22dd
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/panicking.rs:247
   3:     0x7eff0358c2d5 - std::panicking::default_hook::h852b4223c1c00c59
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/panicking.rs:257
   4:     0x7eff0358c9e7 - std::panicking::rust_panic_with_hook::hcd9d05f53fa0dafc
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/panicking.rs:451
   5:     0x7efeffa1c5fa - std::panicking::begin_panic::h2f463d37998ebeba
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/panicking.rs:413
   6:     0x7efeffa2c22a - rustc_errors::Handler::bug::haca77c19c882b432
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_errors/lib.rs:655
   7:     0x7eff00a752a1 - rustc::session::opt_span_bug_fmt::{{closure}}::hfeb850fbe828b399
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/session/mod.rs:727
   8:     0x7eff009b038e - rustc::session::opt_span_bug_fmt::h46e45438a860a75e
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/ty/context.rs:978
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/session/mod.rs:723
   9:     0x7eff009b01d2 - rustc::session::bug_fmt::hde22f071bf5a80ea
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/session/mod.rs:707
  10:     0x7eff02138c58 - <collections::vec::Vec<T> as core::iter::traits::FromIterator<T>>::from_iter::hc5cbb62358ceb057
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/mir/operand.rs:82
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/mir/rvalue.rs:168
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libcore/ops.rs:2648
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libcore/option.rs:383
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libcore/iter/mod.rs:960
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libcollections/vec.rs:1632
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libcollections/vec.rs:1540
  11:     0x7eff021d8e65 - rustc_trans::mir::rvalue::<impl rustc_trans::mir::MirContext<'bcx, 'tcx>>::trans_rvalue::h2a14de75e2fd4285
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libcore/iter/iterator.rs:1196
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/mir/rvalue.rs:167
  12:     0x7eff021c7a16 - rustc_trans::mir::block::<impl rustc_trans::mir::MirContext<'bcx, 'tcx>>::trans_block::he67d3259f79e4177
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/mir/statement.rs:36
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/mir/block.rs:103
  13:     0x7eff021c5e26 - rustc_trans::mir::trans_mir::h2fb44ecb31cfdffa
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/mir/mod.rs:319
  14:     0x7eff02169d8d - rustc_trans::base::trans_closure::h941de14309416d66
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/base.rs:1041
  15:     0x7eff021e50a9 - rustc_trans::trans_item::TransItem::define::h2e690ccd1ee22f95
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/base.rs:1061
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/trans_item.rs:85
  16:     0x7eff0216d08b - rustc_trans::base::trans_crate::h9b06de31ed8799d1
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/base.rs:1641
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/dep_graph/graph.rs:77
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_trans/base.rs:1639
  17:     0x7eff039132a8 - rustc_driver::driver::phase_4_translate_to_llvm::hc3883ea2c4750179
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_driver/driver.rs:1046
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/util/common.rs:38
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_driver/driver.rs:1044
  18:     0x7eff03948f77 - rustc_driver::driver::compile_input::{{closure}}::h9162a2fa292aeb3f
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_driver/driver.rs:206
  19:     0x7eff03940774 - rustc_driver::driver::phase_3_run_analysis_passes::{{closure}}::h1928c4704cfe9c61
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_driver/driver.rs:1000
  20:     0x7eff03911011 - rustc_driver::driver::phase_3_run_analysis_passes::he578df6b8805151c
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/ty/context.rs:949
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/thread/local.rs:245
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/ty/context.rs:946
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/ty/context.rs:933
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/thread/local.rs:245
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/ty/context.rs:930
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc/ty/context.rs:719
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_driver/driver.rs:869
  21:     0x7eff038fa2d6 - rustc_driver::driver::compile_input::h5b63ccd49eeeb98b
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_driver/driver.rs:172
  22:     0x7eff03923109 - rustc_driver::run_compiler::h98c7274e7cb1d11d
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_driver/lib.rs:224
  23:     0x7eff03865018 - std::panicking::try::do_call::h99ed0da044e497c3
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_driver/lib.rs:1148
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_driver/lib.rs:137
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/librustc_driver/lib.rs:1082
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/panic.rs:255
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/panicking.rs:356
  24:     0x7eff03596eca - __rust_maybe_catch_panic
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libpanic_unwind/lib.rs:97
  25:     0x7eff03883028 - <F as alloc::boxed::FnBox<A>>::call_box::hbdd5a14cd8e33b97
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/panicking.rs:332
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/panic.rs:311
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/thread/mod.rs:278
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/liballoc/boxed.rs:595
  26:     0x7eff0358ac84 - std::sys::thread::Thread::new::thread_start::h50b05608a499d2b2
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/liballoc/boxed.rs:605
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/sys/common/thread.rs:21
                        at /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/obj/../src/libstd/sys/unix/thread.rs:84
  27:     0x7efefb8b7453 - start_thread
  28:     0x7eff0325a7de - __GI___clone
  29:                0x0 - <unknown>

[Mark-Simulacrum]

Got an updated backtrace:

error: internal compiler error: src/librustc_trans/mir/operand.rs:111: not immediate: OperandRef(Pair((i8*:i8* getelementptr inbounds ([0 x i8], [0 x i8]* @str.0, i32 0, i32 0)), (i64:i64 0)) @ &str)

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: run with `RUST_BACKTRACE=1` for a backtrace

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:473
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
...
  13: rustc_trans::mir::operand::OperandRef::immediate
             at /rust/src/librustc_trans/mir/operand.rs:111
  14: core::ops::impls::<impl core::ops::FnOnce<A> for &'a mut F>::call_once
             at /rust/src/librustc_trans/mir/statement.rs:83
             at /rust/src/libcore/ops.rs:2710
  15: <collections::vec::Vec<T> as collections::vec::SpecExtend<T, I>>::spec_extend
             at /rust/src/libcore/option.rs:392
             at /rust/src/libcore/iter/mod.rs:1011
             at /rust/src/libcollections/vec.rs:1760
  16: <collections::vec::Vec<T> as collections::vec::SpecExtend<T, I>>::from_iter
             at /rust/src/libcollections/vec.rs:1743
  17: rustc_trans::mir::statement::<impl rustc_trans::mir::MirContext<'a, 'tcx>>::trans_statement
             at /rust/src/libcollections/vec.rs:1630
             at /rust/src/libcore/iter/iterator.rs:1222
             at /rust/src/librustc_trans/mir/statement.rs:82
  18: rustc_trans::mir::block::<impl rustc_trans::mir::MirContext<'a, 'tcx>>::trans_block
             at /rust/src/librustc_trans/mir/block.rs:109
  19: rustc_trans::mir::trans_mir
             at /rust/src/librustc_trans/mir/mod.rs:330
  20: rustc_trans::base::trans_instance
             at /rust/src/librustc_trans/base.rs:606
  21: rustc_trans::trans_item::TransItem::define
             at /rust/src/librustc_trans/trans_item.rs:104
  22: rustc_trans::base::trans_crate::module_translation
             at /rust/src/librustc_trans/base.rs:1182
  23: rustc::dep_graph::graph::DepGraph::with_task
             at /rust/src/librustc/dep_graph/graph.rs:111
  24: core::ops::impls::<impl core::ops::FnOnce<A> for &'a mut F>::call_once
             at /rust/src/librustc_trans/base.rs:1116
             at /rust/src/libcore/ops.rs:2710
  25: <collections::vec::Vec<T> as collections::vec::SpecExtend<T, I>>::spec_extend
             at /rust/src/libcore/option.rs:392
             at /rust/src/libcore/iter/mod.rs:1011
             at /rust/src/libcollections/vec.rs:1760
  26: <collections::vec::Vec<T> as collections::vec::SpecExtend<T, I>>::from_iter
             at /rust/src/libcollections/vec.rs:1743
  27: rustc_trans::base::trans_crate
             at /rust/src/libcollections/vec.rs:1630
             at /rust/src/libcore/iter/iterator.rs:1222
             at /rust/src/librustc_trans/base.rs:1111
  28: rustc::util::common::time
             at /rust/src/librustc_driver/driver.rs:1051
             at /rust/src/librustc/util/common.rs:48
  29: rustc_driver::driver::phase_4_translate_to_llvm
             at /rust/src/librustc_driver/driver.rs:1049
  30: rustc_driver::driver::compile_input::{{closure}}
             at /rust/src/librustc_driver/driver.rs:206
  31: <std::thread::local::LocalKey<T>>::with
             at /rust/src/librustc_driver/driver.rs:1032
             at /rust/src/librustc/ty/context.rs:915
             at /rust/src/libstd/thread/local.rs:253
  32: rustc::ty::context::tls::enter
             at /rust/src/librustc/ty/context.rs:912
  33: <std::thread::local::LocalKey<T>>::with
             at /rust/src/librustc/ty/context.rs:899
             at /rust/src/libstd/thread/local.rs:253
  34: rustc::ty::context::tls::enter_global
             at /rust/src/librustc/ty/context.rs:896
  35: rustc::ty::context::TyCtxt::create_and_enter
             at /rust/src/librustc/ty/context.rs:706
  36: rustc_driver::driver::phase_3_run_analysis_passes
             at /rust/src/librustc_driver/driver.rs:940
  37: rustc_driver::driver::compile_input
             at /rust/src/librustc_driver/driver.rs:172
  38: rustc_driver::run_compiler
             at /rust/src/librustc_driver/lib.rs:224

[gmorenz]

Ran into this with

#![feature(asm)]

#[repr(C)]
struct MyPtr(usize);

fn main() {
    unsafe {
        let target = MyPtr(0);
        asm!( "ret" : : "{rdi}"(target) );
    }
}

which I would sort of hope would just work. Backtrace is identical (at least as far as a compiler without debugging information outputs).

[istankovic]

Still reproducible with rustc 1.26.0-nightly (adf2135ad 2018-03-17).

[levex]

No longer reproduces:

$ rustc +nightly 37433.rs
error[E0669]: invalid value for constraint in inline assembly
 --> 37433.rs:5:9
  |
5 |         asm!("" :: "r"(""));
  |         ^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0669`.
$ rustc +nightly 37433-2.rs 
error[E0669]: invalid value for constraint in inline assembly
 --> 37433-2.rs:9:9
  |
9 |         asm!( "ret" : : "{rdi}"(target) );
  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0669`.
$ rustc +nightly -vV
rustc 1.31.0-nightly (77af31408 2018-10-11)
binary: rustc
commit-hash: 77af314083e5acabf9ba5335e47271f35eef2e99
commit-date: 2018-10-11
host: x86_64-unknown-linux-gnu
release: 1.31.0-nightly
LLVM version: 8.0