llvm/llvm/test/FileCheck/bad-char.txt

# This file contains characters that render as spaces (at least for me in vim)
# but are encoded as 160.  Each is indicated with a "^" on the following line.
# FileCheck used to call functions like isalnum on each without casting to
# unsigned char first, so it sign-extended beyond what unsigned char or EOF can
# represent.  C says that has undefined behavior, and it has caused stack dumps
# under Windows.

//------------------------------------------------
RUN: %ProtectFileCheckOutput \
RUN: not FileCheck -check-prefix=BEFORE-PREFIX %s < /dev/null 2>&1 | \
RUN:   FileCheck -check-prefix=ERR-EMPTY-CHECK %s

 BEFORE-PREFIX:
^
ERR-EMPTY-CHECK: error: found empty check string

//------------------------------------------------
RUN: %ProtectFileCheckOutput \
RUN: not FileCheck -check-prefix=AFTER-PREFIX %s < /dev/null 2>&1 | \
RUN:   FileCheck -check-prefix=ERR-NO-CHECK %s

AFTER-PREFIX :
            ^
ERR-NO-CHECK: error: no check strings found

//------------------------------------------------
RUN: %ProtectFileCheckOutput \
RUN: not FileCheck -check-prefix=BEFORE-VAR %s < /dev/null 2>&1 | \
RUN:   FileCheck -check-prefix=ERR-BAD-VAR %s

BEFORE-VAR: [[ VAR:]]
              ^
ERR-BAD-VAR: error: invalid variable name

//------------------------------------------------
RUN: %ProtectFileCheckOutput \
RUN: not FileCheck -check-prefix=AFTER-VAR %s < /dev/null 2>&1 | \
RUN:   FileCheck -check-prefix=ERR-BAD-STRING-VAR %s

AFTER-VAR: [[VAR :]]
                ^
ERR-BAD-STRING-VAR: error: invalid name in string variable definition