test/CodeGen/MIR/X86/undefined-virtual-register.mir

# RUN: not llc -march=x86-64 -start-after machine-sink -stop-after machine-sink -o /dev/null %s 2>&1 | FileCheck %s
# This test ensures that the MIR parser reports an error when parsing a
# reference to an undefined virtual register.

--- |

  define i32 @test(i32 %a) {
  entry:
    ret i32 %a
  }

...
---
name:            test
isSSA:           true
tracksRegLiveness: true
registers:
  - { id: 0, class: gr32 }
body:
  - id:          0
    name:        entry
    instructions:
      - '%0 = COPY %edi'
      # CHECK: [[@LINE+1]]:22: use of undefined virtual register '%10'
      - '%eax = COPY %10'
      - 'RETQ %eax'
...