[macOS] Lldb crashes while debugging rustc

[bjorn3]

$ lldb -n rustc -w
(lldb) process attach --name "rustc" --waitfor
Process 61982 stopped
* thread #1, stop reason = signal SIGSTOP
    frame #0: 0x000000011367419c dyld`_dyld_start
dyld`_dyld_start:
->  0x11367419c <+0>: popq   %rdi
    0x11367419d <+1>: pushq  $0x0
    0x11367419f <+3>: movq   %rsp, %rbp
    0x1136741a2 <+6>: andq   $-0x10, %rsp
Target 0: (rustc) stopped.

Executable module set to "/Users/bjorn/Documents/rust-fork/build/x86_64-apple-darwin/stage2/bin/rustc".
Architecture set to: x86_64h-apple-macosx.
(lldb) continue 
Process 61982 resuming
librustc_driver-dcdd823ad86bd03e.dylib was compiled with optimization - stepping may behave oddly; variables may not be available.
Process 61982 stopped
* thread #2, name = 'rustc', stop reason = EXC_BAD_ACCESS (code=1, address=0x105ee3078)
    frame #0: 0x0000000105b55a87 librustc_driver-dcdd823ad86bd03e.dylib`core::ptr::drop_in_place::hdc80d0e2f0000db2 [inlined] core::ptr::drop_in_place::h070b89da4f520733 at ptr.rs:59 [opt]
   56  	#[stable(feature = "drop_in_place", since = "1.8.0")]
   57  	#[lang = "drop_in_place"]
   58  	#[allow(unconditional_recursion)]
-> 59  	pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
   60  	    // Code here does not matter - this is replaced by the
   61  	    // real drop glue by the compiler.
   62  	    drop_in_place(to_drop);
Target 0: (rustc) stopped.
(lldb) bt
error: librustc_driver-dcdd823ad86bd03e.dylib DWARF DIE at 0x002af064 (class closure) has a member variable 0x002af06b (__0) whose type is a forward declaration, not a complete definition.
Try compiling the source file with -fno-limit-debug-info
Illegal instruction: 4
$

[rust]
debuginfo = true
debuginfo-lines = true

[king6cong]

similar here:

(lldb) t 16
* thread #16, name = 't:tokio'
    frame #0: 0x00007fff7d5d3bf2 libsystem_kernel.dylib`kevent + 10
libsystem_kernel.dylib`kevent:
->  0x7fff7d5d3bf2 <+10>: jae    0x7fff7d5d3bfc            ; <+20>
    0x7fff7d5d3bf4 <+12>: movq   %rax, %rdi
    0x7fff7d5d3bf7 <+15>: jmp    0x7fff7d5c9b00            ; cerror_nocancel
    0x7fff7d5d3bfc <+20>: retq
(lldb) list
(lldb) bt
warning: (x86_64) /xxx/target/debug/deps/libmio-8461a2db86d1af74.rlib(mio-8461a2db86d1af74.mio8.rcgu.o) 0xfdc00000d4d: DW_TAG_member bitfield named "(null)" has invalid bit offset (0x100000000) member will be ignored. Please file a bug against the compiler and include the preprocessed output for /Users/cong/.cargo/registry/src/github.com-1ecc6299db9ec823/mio-0.6.9/src/lib.rs/@/mio8

error: liblib_net-22a2ad34bc598d14.rlib(lib_net-22a2ad34bc598d14.35a0x8f7rhy3adti.rcgu.o) DWARF DIE at 0x0000195f (class Option<core::result::Result<(), ()>>) has a member variable 0x00001966 (RUST$ENCODED$ENUM$0$None) whose type is a forward declaration, not a complete definition.
Try compiling the source file with -fstandalone-debug
Segmentation fault: 11

seems to be related to: #41193

[fanzeyi]

Same issue here. It works fine before when I was using standard lldb. (Then I discovered rust-lldb and decided to give it a try and run into this bug.)

What I did:

> attach <PID>
> thread list
> thread select 2
> bt
..Segmentation Fault...

error: xxx DWARF DIE at 0x000283c3 (class closure) has a member variable 0x000283ca (__0) whose type is a forward declaration, not a complete definition.
Try compiling the source file with -fno-limit-debug-info
$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rust-lldb: line 41: 98247 Segmentation fault: 11  lldb --source-before-file="$TMPFILE" "$@"

$ rustc --version
rustc 1.30.0-nightly (73c78734b 2018-08-05)
$ rust-lldb --version
lldb-902.0.79.7
  Swift-4.1

[jasonwilliams]

I think (the DWARF DIE error) is a duplicate of #29154
This issue was also raised in vadimcn/codelldb#127

[tromey]

I think this is the same as #41193, and since there is more analysis there, I am closing this one.