Check commands¶

If you are new to FileCheck, please make sure you have read the tutorials: Tutorial: Hello World and Tutorial: LIT and FileCheck because they show how FileCheck is used: standalone and in combination with LIT.

For all of the examples below, please note:

.check extension is chosen arbitrarily. FileCheck can work with any file names.

CHECK¶

CHECK command means that a given string or a regular expression must be present in input provided to FileCheck.

Create a new file CHECK.check with the following contents:

CHECK: String1
CHECK: String2
CHECK: String3

Valid input results in the exit code 0 that indicates success:

printf "String1\nString2\nString3" | filecheck CHECK.check
/Users/Stanislaw/.pyenv/versions/3.5.0/bin/filecheck

Invalid input results in the exit code 1 and error message:

echo "String1" | filecheck CHECK.check
/Users/Stanislaw/.pyenv/versions/3.5.0/bin/filecheck
CHECK.check:2:8: error: CHECK: expected string not found in input
CHECK: String2
       ^
<stdin>:1:8: note: scanning from here
String1
       ^

Order of matching¶

CHECK commands are checked one after another. If a CHECK string is not found in output, FileCheck exits with error immediately.

Create a new file order-of-matching.check with the following contents:

CHECK: String1
CHECK: String2
CHECK: String3

And run with invalid input:

echo "String1" | filecheck order-of-matching.check
...
order-of-matching.check:2:8: error: CHECK: expected string not found in input
CHECK: String2
       ^
<stdin>:1:8: note: scanning from here
String1
       ^

CHECK-NOT¶

CHECK-NOT is the opposite of CHECK: a given string or a regular expression must not be present in input provided to FileCheck.

Example¶

CHECK-NOT.check file:

CHECK-NOT: String1
CHECK-NOT: String2
CHECK-NOT: String3

$ echo "String3" | filecheck CHECK-NOT.check
filecheck
CHECK-NOT.check:3:12: error: CHECK-NOT: excluded string found in input
CHECK-NOT: String3
           ^
<stdin>:1:1: note: found here
String3
^~~~~~~

CHECK-NEXT¶

CHECK-NEXT command means that a given string or a regular expression must be present in input provided to FileCheck. Additionally, there must be another check right before CHECK-NEXT, that has passed on the input line just before the current input line. CHECK-NEXT cannot be the first check in the check file.

Check file CHECK-NEXT.check:

CHECK: String1
CHECK-NEXT: String2

$ printf "String1\nString2" | filecheck CHECK-NEXT.check
...filecheck
$ echo $?
0

$ printf "String1\nfoo\nString2" | filecheck CHECK-NEXT.check
...filecheck
CHECK-NEXT.check:2:13: error: CHECK-NEXT: is not on the line after the previous match
CHECK-NEXT: String2
            ^
<stdin>:3:1: note: 'next' match was here
String2
^
<stdin>:1:8: note: previous match ended here
String1
       ^
<stdin>:2:1: note: non-matching line after previous match is here
foo
^

CHECK-EMPTY¶

CHECK-EMPTY command is used to match empty lines.

Consider the following check file:

CHECK: String1
CHECK-EMPTY:
CHECK: String2

In the following example, there is an empty line so the test will pass:

$ printf "String1\n\nString2" | filecheck CHECK-EMPTY.check
...filecheck
$ echo $?
0

If the empty line is removed, the test will fail:

$ printf "String1\nString2" | filecheck CHECK-EMPTY.check
...filecheck
...CHECK-EMPTY.check:2:13: error: CHECK-EMPTY: expected string not found in input
CHECK-EMPTY:
            ^
<stdin>:2:1: note: scanning from here
String2
^
$ echo $?
1

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