Why would you grep for the emoji? The actual pattern you want to match is the standard format of the error message that proceeds it, which hasn’t changed in eons:
my $line = "infinite-loop-linked-list.c:30:10: warning: infinite loop [CWE-835] [-Wanalyzer-infinite-loop]";
grammar gcc {
token filename { + };
token linenumber { \d+ };
token colnumber { \d+ };
token severity { info|warning|error };
token message { .* $$ };
regex diagnostic {
[\:]
[\:]
[\:]\s
[\:]\s
};
token TOP { };
}
say gcc.parse($line);
which when run produces the obvious output:
｢infinite-loop-linked-list.c:30:10: warning: infinite loop [CWE-835] [-Wanalyzer-infinite-loop]｣
diagnostic => ｢infinite-loop-linked-list.c:30:10: warning: infinite loop [CWE-835] [-Wanalyzer-infinite-loop]｣
filename => ｢infinite-loop-linked-list.c｣
linenumber => ｢30｣
colnumber => ｢10｣
severity => ｢warning｣
message => ｢infinite loop [CWE-835] [-Wanalyzer-infinite-loop]｣
I’ll leave handling filenames containing colons as an exercise for the reader.
The emoji just focus the reader’s eye on the most critical line of the explanation.