tldr/pages/common/filecheck.md

FileCheck

Flexible pattern matching file verifier. It is typically used from LLVM regression tests and forms a part of a lit test. More information: https://llvm.org/docs/CommandGuide/FileCheck.html.

• Match input_file content with pattern file check_file:

FileCheck --input-file={{path/to/input_file}} {{path/to/check_file}}

• Match input from the stdin with pattern file check_file:

echo "{{some_text}}" | FileCheck {{path/to/check_file}}

• Match with the specified custom check prefix (Note: the default prefix is CHECK):

echo "{{some_text}}" | FileCheck --check-prefix={{prefix}} {{path/to/check_file}}

• Print good directive pattern matches:

echo "{{some_text}}" | FileCheck -v {{path/to/check_file}}

• Input llvm_code.ll into llvm-as, then pipe the output into FileCheck to match:

llvm-as {{path/to/llvm_code.ll}} | FileCheck {{path/to/check_file}}