internal compiler error: unexpected panic for issue #35896

[gasabr]

I'm learning rust and diesel, while trying to get the diesel::association::BelongTo working on my table, I tried this code:

#[derive(Queryable, Identifiable, BelongsTo::User, Clone)]
pub struct Game {
    pub id: i32,
    pub name: String,
    pub admin: i32,
    pub pwd: Option<String>,
    pub messages_enabled: bool,
    pub private: bool,
    pub n_players: i32,
    pub status: String,
}

I expected to see this happen: Nothing, to be honest, I thought BelongsTo::<User> should work, and BelongsTo::User does not make any sense to me.

Instead, this happened: I got the error message telling me to report this bug.

Meta

rustc --version --verbose:

rustc 1.21.0 (3b72af97e 2017-10-09)
binary: rustc
commit-hash: 3b72af97e42989b2fe104d8edbaee123cdf7c58f
commit-date: 2017-10-09
host: x86_64-apple-darwin
release: 1.21.0
LLVM version: 4.0

Backtrace:

   Compiling gotgame v0.1.0 (file:///Users/gasabr/Coding/gotgame)
error: non-ident macro paths are experimental (see issue #35896)
  --> src/models.rs:47:35
   |
47 | #[derive(Queryable, Identifiable, BelongsTo::User, Clone)]
   |                                   ^^^^^^^^^^^^^^^

error: internal compiler error: unexpected panic

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: rustc 1.21.0 (3b72af97e 2017-10-09) running on x86_64-apple-darwin

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

thread 'rustc' panicked at 'Expected Def::Macro(..)', src/librustc_resolve/build_reduced_graph.rs:555:17
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace
   1: std::panicking::default_hook::{{closure}}
   2: std::panicking::default_hook
   3: std::panicking::rust_panic_with_hook
   4: std::panicking::begin_panic
   5: rustc_resolve::build_reduced_graph::<impl rustc_resolve::Resolver<'a>>::get_macro
   6: rustc_resolve::macros::<impl syntax::ext::base::Resolver for rustc_resolve::Resolver<'a>>::resolve_invoc
   7: syntax::ext::expand::MacroExpander::expand
   8: syntax::ext::expand::MacroExpander::expand_crate
   9: rustc_driver::driver::phase_2_configure_and_expand::{{closure}}
  10: rustc_driver::driver::phase_2_configure_and_expand
  11: rustc_driver::driver::compile_input
  12: rustc_driver::run_compiler

[kennytm]

Repro with 1.23-nightly on playground. Smaller test case:

#![feature(use_extern_macros)]
trait Foo {}
#[derive(Foo::Anything)]
struct S;

The input still ICE without #![feature(use_extern_macros)], but with a different stack trace.

error: non-ident macro paths are experimental (see issue #35896)
 --> 1.rs:3:10
  |
3 | #[derive(Foo::Anything)]
  |          ^^^^^^^^^^^^^
  |
  = help: add #![feature(use_extern_macros)] to the crate attributes to enable

error: internal compiler error: unexpected panic

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: rustc 1.23.0-nightly (aabfed5e0 2017-11-17) running on x86_64-apple-darwin

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

thread 'rustc' panicked at 'no entry found for key', src/libcore/option.rs:874:4
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace
   1: std::sys_common::backtrace::_print
   2: std::panicking::default_hook::{{closure}}
   3: std::panicking::default_hook
   4: std::panicking::rust_panic_with_hook
   5: std::panicking::begin_panic
   6: std::panicking::begin_panic_fmt
   7: rust_begin_unwind
   8: core::panicking::panic_fmt
   9: core::option::expect_failed
  10: rustc_resolve::build_reduced_graph::<impl rustc_resolve::Resolver<'a>>::macro_def_scope
  11: rustc_resolve::macros::<impl syntax::ext::base::Resolver for rustc_resolve::Resolver<'a>>::resolve_invoc
  12: _ZN6syntax3ext6expand13MacroExpander6expand17h0e8dd401d8088c1eE.llvm.BAEFEFD9
  13: syntax::ext::expand::MacroExpander::expand_crate
  14: _ZN12rustc_driver6driver28phase_2_configure_and_expand28_$u7b$$u7b$closure$u7d$$u7d$17h519a719775ba2532E.llvm.E320C00D
  15: rustc::util::common::time
  16: rustc_driver::driver::compile_input
  17: rustc_driver::run_compiler

[arielb1]

cc @jseyfried

ICE backtrace without the #![feature]:

$ RUST_BACKTRACE=1 ./build/x86_64-unknown-linux-gnu/stage1/bin/rustc ice.rs 2>&1 | sed 's@/home/ariel/Rust/rust-master@rust:/@g'error: non-ident macro paths are experimental (see issue #35896)
 --> ice.rs:3:10
  |
3 | #[derive(Foo::Anything)]                                                                                                                                                                         
  |          ^^^^^^^^^^^^^                                                                                                                                                                           
  |                                                                                                                                                                                                  
  = help: add #![feature(use_extern_macros)] to the crate attributes to enable                                                                                                                       
                                                                                                                                                                                                     
error: internal compiler error: unexpected panic                                                                                                                                                     
                                                                                                                                                                                                     
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: rustc 1.23.0-dev running on x86_64-unknown-linux-gnu                                                                                                                                           
                                                                                                                                                                                                     
note: run with `RUST_BACKTRACE=1` for a backtrace                                                                                                                                                    
                                                                                                                                                                                                     
thread 'rustc' panicked at 'no entry found for key', rust://src/libcore/option.rs:874:4                                                                                                              
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.                                                                                                              
stack backtrace:                                                                                                                                                                                     
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace                                                                                                                                       
             at rust://src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49                                                                                                                             
   1: std::sys_common::backtrace::_print                                                                                                                                                             
             at rust://src/libstd/sys_common/backtrace.rs:68                                                                                                                                         
   2: std::panicking::default_hook::{{closure}}                                                                                                                                                      
             at rust://src/libstd/sys_common/backtrace.rs:57                                                                                                                                         
             at rust://src/libstd/panicking.rs:381                                                                                                                                                   
   3: std::panicking::default_hook                                                                                                                                                                   
             at rust://src/libstd/panicking.rs:391                                                                                                                                                   
   4: std::panicking::rust_panic_with_hook                                                                                                                                                           
             at rust://src/libstd/panicking.rs:577                                                                                                                                                   
   5: std::panicking::begin_panic                                                                                                                                                                    
             at rust://src/libstd/panicking.rs:538                                                                                                                                                   
   6: std::panicking::begin_panic_fmt                                                                                                                                                                
             at rust://src/libstd/panicking.rs:522                                                                                                                                                   
   7: rust_begin_unwind                                                                                                                                                                              
             at rust://src/libstd/panicking.rs:498                                                                                                                                                   
   8: core::panicking::panic_fmt                                                                                                                                                                     
             at rust://src/libcore/panicking.rs:71                                                                                                                                                   
   9: core::option::expect_failed                                                                                                                                                                    
             at rust://src/libcore/option.rs:874                                                                                                                                                     
  10: rustc_resolve::build_reduced_graph::<impl rustc_resolve::Resolver<'a>>::macro_def_scope                                                                                                        
             at rust://src/librustc_resolve/build_reduced_graph.rs:0                                                                                                                                 
  11: rustc_resolve::macros::<impl syntax::ext::base::Resolver for rustc_resolve::Resolver<'a>>::resolve_invoc                                                                                       
             at rust://src/librustc_resolve/macros.rs:295                                                                                                                                            
  12: syntax::ext::expand::MacroExpander::expand                                                                                                                                                     
             at rust://src/libsyntax/ext/expand.rs:285                                                                                                                                               
  13: syntax::ext::expand::MacroExpander::expand_crate                                                                                                                                               
             at rust://src/libsyntax/ext/expand.rs:240                                                                                                                                               
  14: rustc_driver::driver::phase_2_configure_and_expand::{{closure}}
             at rust://src/librustc_driver/driver.rs:783
  15: rustc_driver::driver::phase_2_configure_and_expand
             at rust://src/librustc/util/common.rs:120
             at rust://src/librustc_driver/driver.rs:742
  16: rustc_driver::driver::compile_input
             at rust://src/librustc_driver/driver.rs:145
  17: rustc_driver::run_compiler
             at rust://src/librustc_driver/lib.rs:253

With the #![feature]:

error: internal compiler error: unexpected panic

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: rustc 1.23.0-dev running on x86_64-unknown-linux-gnu

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

thread 'rustc' panicked at 'Expected Def::Macro(..)', rust://src/librustc_resolve/build_reduced_graph.rs:571:17
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace
             at rust://src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::_print
             at rust://src/libstd/sys_common/backtrace.rs:68
   2: std::panicking::default_hook::{{closure}}
             at rust://src/libstd/sys_common/backtrace.rs:57
             at rust://src/libstd/panicking.rs:381
   3: std::panicking::default_hook
             at rust://src/libstd/panicking.rs:391
   4: std::panicking::rust_panic_with_hook
             at rust://src/libstd/panicking.rs:577
   5: std::panicking::begin_panic
             at rust://src/libstd/panicking.rs:538
   6: rustc_resolve::build_reduced_graph::<impl rustc_resolve::Resolver<'a>>::get_macro
             at rust://src/librustc_resolve/build_reduced_graph.rs:571
   7: rustc_resolve::macros::<impl syntax::ext::base::Resolver for rustc_resolve::Resolver<'a>>::resolve_macro
             at rust://src/librustc_resolve/macros.rs:310
             at rust://src/libcore/result.rs:468
             at rust://src/librustc_resolve/macros.rs:308
   8: syntax::ext::expand::MacroExpander::expand
             at rust://src/libsyntax/ext/expand.rs:340
   9: syntax::ext::expand::MacroExpander::expand_crate
             at rust://src/libsyntax/ext/expand.rs:240
  10: rustc_driver::driver::phase_2_configure_and_expand::{{closure}}
             at rust://src/librustc_driver/driver.rs:783
  11: rustc_driver::driver::phase_2_configure_and_expand
             at rust://src/librustc/util/common.rs:120
             at rust://src/librustc_driver/driver.rs:742
  12: rustc_driver::driver::compile_input
             at rust://src/librustc_driver/driver.rs:145
  13: rustc_driver::run_compiler
             at rust://src/librustc_driver/lib.rs:253

[arielb1]

Looks like we have some debuginfo corruption:

  10: rustc_resolve::build_reduced_graph::<impl rustc_resolve::Resolver<'a>>::macro_def_scope                                                                                                        
             at rust://src/librustc_resolve/build_reduced_graph.rs:0                                                                                                                                 

[arielb1]

cc @michaelwoerister - could you try to figure out why we have debuginfo corruption in librustc_resolve?

[michaelwoerister]

@arielb1 Looks like #44465 (which might be related to libbacktrace not fully supporting debuginfo for inlined functions). As far as I know nobody is looking into this issue at the moment.

[arielb1]

@michaelwoerister

The bugzilla looks like rustc is injecting line number 0 for some reason. I'll investigate.

[arielb1]

It looks like the "bad" line number comes from an unreachable following the call to expect_failed. I thought our unwinder was smart enough to use the line number of 1 byte before the return address (which should be within the call instruction) rather than the line number of the return address, but apparently libbacktrace doesn't do that.

        .loc    12 302 0
        leaq    str.k.llvm.133BC46B(%rip), %rdi
.Ltmp34:
        movl    $22, %esi
        callq   _ZN4core6option13expect_failed17hfad3c6cc869d0a50E@PLT
.Ltmp35:
        .loc    12 0 0 is_stmt 0
        ud2

[arielb1]

Nope, that's not the problem. The LLVM IR above works with libbacktrace (this was generated using LTO, which massages the IR in a way it does not encounter the problem).

[estebank]

Can't repro on stable or nightly.