llvm/test/MC/ELF/subtraction-error.s - llvm-project - Git at Google

 // RUN: not llvm-mc -filetype=obj -triple x86_64-pc-linux < %s 2>&1 | FileCheck %s

 a:
     .section foo
 b:
 c = b - a

 ; CHECK: symbol 'a' could not be evaluated in a subtraction expression
	// RUN: not llvm-mc -filetype=obj -triple x86_64-pc-linux < %s 2>&1 \| FileCheck %s

	a:
	.section foo
	b:
	c = b - a

	; CHECK: symbol 'a' could not be evaluated in a subtraction expression