perf tools: Complete tracepoint event names

Currently tracepoint events cannot be completed because they contain a
colon (:) character.  The colon is considered as a word separator when
bash completion is done - variable COMP_WORDBREAKS contains colon - so
if a word being completed contains a colon it can be a problem.

Recent versions of bash completion provide -n switch to
_get_comp_words_by_ref and __ltrim_colon_completions functions in order
to resolve this issue.  Copy the latter in case not exists.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1349328234-16995-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/bash_completion

@@ -6,16 +6,29 @@ function_exists()
 	return $?
 }
 
+function_exists __ltrim_colon_completions ||
+__ltrim_colon_completions()
+{
+	if [[ "$1" == *:* && "$COMP_WORDBREAKS" == *:* ]]; then
+		# Remove colon-word prefix from COMPREPLY items
+		local colon_word=${1%${1##*:}}
+		local i=${#COMPREPLY[*]}
+		while [[ $((--i)) -ge 0 ]]; do
+			COMPREPLY[$i]=${COMPREPLY[$i]#"$colon_word"}
+		done
+	fi
+}
+
 have perf &&
 _perf()
 {
 	local cur prev cmd
 
 	COMPREPLY=()
 	if function_exists _get_comp_words_by_ref; then
-		_get_comp_words_by_ref cur prev
+		_get_comp_words_by_ref -n : cur prev
 	else
-		cur=$(_get_cword)
+		cur=$(_get_cword :)
 		prev=${COMP_WORDS[COMP_CWORD-1]}
 	fi
 
@@ -35,6 +48,7 @@ _perf()
 	elif [[ $prev == "-e" && "${COMP_WORDS[1]}" == @(record|stat|top) ]]; then
 		evts=$($cmd list --raw-dump)
 		COMPREPLY=( $( compgen -W '$evts' -- "$cur" ) )
+		__ltrim_colon_completions $cur
 	# List long option names
 	elif [[ $cur == --* ]];  then
 		subcmd=${COMP_WORDS[1]}