perf tools: Fix the bash completion for listing subsubcommands of perf subcommand

The bash completion does not support listing subsubcommands for 'perf
kvm|kmem|mem|lock|sched --<long option> <TAB>', where 'kvm|kmem|mem|
lock|sched' are all subcommands of perf.

Example:

Before this patch:

 $ perf kvm --verbose <TAB>
 $

As shown above, the subsubcommands of perf kvm does not come out.

After this patch:

 $ perf kvm --verbose <TAB>
 buildid-list  diff          record        report        stat
 top

As shown above, the subsubcommands of perf kvm can come out now.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1426685758-25488-3-git-send-email-yunlong.song@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/perf-completion.sh b/tools/perf/perf-completion.sh
index 4822ed3..bbb61d0 100644 (file)
--- a/tools/perf/perf-completion.sh
+++ b/tools/perf/perf-completion.sh
@@ -100,6 +100,23 @@ __perfcomp_colon ()
        __ltrim_colon_completions $cur
 }
 
+__perf_prev_skip_opts ()
+{
+       local i cmd_ cmds_
+
+       let i=cword-1
+       cmds_=$($cmd --list-cmds)
+       prev_skip_opts=()
+       while [ $i -ge 0 ]; do
+               for cmd_ in $cmds_; do
+                       if [[ ${words[i]} == $cmd_ ]]; then
+                               prev_skip_opts=${words[i]}
+                               return
+                       fi
+               done
+               ((i--))
+       done
+}
 __perf_main ()
 {
        local cmd
@@ -107,6 +124,8 @@ __perf_main ()
        cmd=${words[0]}
        COMPREPLY=()
 
+       # Skip options backward and find the last perf command
+       __perf_prev_skip_opts
        # List perf subcommands or long options
        if [ $cword -eq 1 ]; then
                if [[ $cur == --* ]]; then
@@ -121,8 +140,8 @@ __perf_main ()
                __perfcomp_colon "$evts" "$cur"
        else
                # List subcommands for perf commands
-               if [[ $prev == @(kvm|kmem|mem|lock|sched) ]]; then
-                       subcmds=$($cmd $prev --list-cmds)
+               if [[ $prev_skip_opts == @(kvm|kmem|mem|lock|sched) ]]; then
+                       subcmds=$($cmd $prev_skip_opts --list-cmds)
                        __perfcomp_colon "$subcmds" "$cur"
                fi
                # List long option names