linux-stable/tools/perf/perf-completion.sh
Yunlong Song 1312c8a8fb perf tools: Avoid confusion with preloaded bash function for perf bash completion
Since some functions (e.g. '_get_comp_words_by_ref()') in perf bash
completion script are originally taken from git bash completion script,
these functions may be preloaded before perf bash completion script
runs.

In order to avoid repeating loading the same function twice, some test
constraints are used before these function definitions in the perf bash
completion script (e.g. 'type _get_comp_words_by_ref &>/dev/null ||').

The problem is that, if these functions in perf bash completion script
are changed for some reason, perf will still use the preloaded bash
functions rather than the customized functions of its own.

As a result, the perf bash completion will behave incorrectly. To get
rid of this problem, a flag can be defined to determine the proper
situation.

And to avoid overwriting the preloaded functions, the names of these
functions in perf bash completion script should be renamed to the
perf-customized ones.

Example:

Before this patch:

 $ type _get_comp_words_by_ref
 _get_comp_words_by_ref is a function
 _get_comp_words_by_ref ()
 {
     local exclude flag i OPTIND=1;
     local cur cword words=();
     local upargs=() upvars=() vcur vcword vprev vwords;
     while getopts "c:i:n:p:w:" flag "$@"; do
         case $flag in
             c)
                 vcur=$OPTARG
             ;;
             i)
                 vcword=$OPTARG
             ;;
             n)
                 exclude=$OPTARG
             ;;
             p)
                 vprev=$OPTARG
             ;;
             w)
                 vwords=$OPTARG
             ;;
         esac;
     done;
     while [[ $# -ge $OPTIND ]]; do
         case ${!OPTIND} in
             cur)
                 vcur=cur
             ;;
             prev)
                 vprev=prev
             ;;
             cword)
                 vcword=cword
             ;;
             words)
                 vwords=words
             ;;
             *)
                 echo "bash: $FUNCNAME(): \`${!OPTIND}': unknown argument" 1>&2;
                 return 1
             ;;
         esac;
         let "OPTIND += 1";
     done;
     __get_cword_at_cursor_by_ref "$exclude" words cword cur;
     [[ -n $vcur ]] && {
         upvars+=("$vcur");
         upargs+=(-v $vcur "$cur")
     };
     [[ -n $vcword ]] && {
         upvars+=("$vcword");
         upargs+=(-v $vcword "$cword")
     };
     [[ -n $vprev && $cword -ge 1 ]] && {
         upvars+=("$vprev");
         upargs+=(-v $vprev "${words[cword - 1]}")
     };
     [[ -n $vwords ]] && {
         upvars+=("$vwords");
         upargs+=(-a${#words[@]} $vwords "${words[@]}")
     };
     (( ${#upvars[@]} )) && local "${upvars[@]}" && _upvars "${upargs[@]}"
 }

As shown above, the _get_comp_words_by_ref is the preloaded function in
fact, rather than the function defined in perf-completion.sh. So if we
happen to change the function for some reason, the result will behave in
a wrong state.

After this patch:

We can set preload_get_comp_words_by_ref="false" to not use the preloaded
function. Instead, it will use the function defined in perf-completion.sh,
which is renamed as __perf_get_comp_words_by_ref to avoid overwriting
the preloaded function _get_comp_words_by_ref.

 $ type __perf_get_comp_words_by_ref
 __perf_get_comp_words_by_ref is a function
 __perf_get_comp_words_by_ref ()
 {
     local exclude cur_ words_ cword_;
     if [ "$1" = "-n" ]; then
         exclude=$2;
         shift 2;
     fi;
     __my_reassemble_comp_words_by_ref "$exclude";
     cur_=${words_[cword_]};
     while [ $# -gt 0 ]; do
         case "$1" in
             cur)
                 cur=$cur_
             ;;
             prev)
                 prev=${words_[$cword_-1]}
             ;;
             words)
                 words=("${words_[@]}")
             ;;
             cword)
                 cword=$cword_
             ;;
         esac;
         shift;
     done
 }

As shown above, the function __perf_get_comp_words_by_ref is loaded and
can work this time.

Note that we do not change the original behavior when those functions are
not preloaded before perf bash completion script runs. In this case,
although the flag is set to "true", the code will still change it to
"false" to use the function defined in perf-completion.sh.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1426685758-25488-14-git-send-email-yunlong.song@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-03-19 13:53:27 -03:00

258 lines
5.3 KiB
Bash

# perf bash and zsh completion
# Taken from git.git's completion script.
__my_reassemble_comp_words_by_ref()
{
local exclude i j first
# Which word separators to exclude?
exclude="${1//[^$COMP_WORDBREAKS]}"
cword_=$COMP_CWORD
if [ -z "$exclude" ]; then
words_=("${COMP_WORDS[@]}")
return
fi
# List of word completion separators has shrunk;
# re-assemble words to complete.
for ((i=0, j=0; i < ${#COMP_WORDS[@]}; i++, j++)); do
# Append each nonempty word consisting of just
# word separator characters to the current word.
first=t
while
[ $i -gt 0 ] &&
[ -n "${COMP_WORDS[$i]}" ] &&
# word consists of excluded word separators
[ "${COMP_WORDS[$i]//[^$exclude]}" = "${COMP_WORDS[$i]}" ]
do
# Attach to the previous token,
# unless the previous token is the command name.
if [ $j -ge 2 ] && [ -n "$first" ]; then
((j--))
fi
first=
words_[$j]=${words_[j]}${COMP_WORDS[i]}
if [ $i = $COMP_CWORD ]; then
cword_=$j
fi
if (($i < ${#COMP_WORDS[@]} - 1)); then
((i++))
else
# Done.
return
fi
done
words_[$j]=${words_[j]}${COMP_WORDS[i]}
if [ $i = $COMP_CWORD ]; then
cword_=$j
fi
done
}
# Define preload_get_comp_words_by_ref="false", if the function
# __perf_get_comp_words_by_ref() is required instead.
preload_get_comp_words_by_ref="true"
if [ $preload_get_comp_words_by_ref = "true" ]; then
type _get_comp_words_by_ref &>/dev/null ||
preload_get_comp_words_by_ref="false"
fi
[ $preload_get_comp_words_by_ref = "true" ] ||
__perf_get_comp_words_by_ref()
{
local exclude cur_ words_ cword_
if [ "$1" = "-n" ]; then
exclude=$2
shift 2
fi
__my_reassemble_comp_words_by_ref "$exclude"
cur_=${words_[cword_]}
while [ $# -gt 0 ]; do
case "$1" in
cur)
cur=$cur_
;;
prev)
prev=${words_[$cword_-1]}
;;
words)
words=("${words_[@]}")
;;
cword)
cword=$cword_
;;
esac
shift
done
}
# Define preload__ltrim_colon_completions="false", if the function
# __perf__ltrim_colon_completions() is required instead.
preload__ltrim_colon_completions="true"
if [ $preload__ltrim_colon_completions = "true" ]; then
type __ltrim_colon_completions &>/dev/null ||
preload__ltrim_colon_completions="false"
fi
[ $preload__ltrim_colon_completions = "true" ] ||
__perf__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
}
__perfcomp ()
{
COMPREPLY=( $( compgen -W "$1" -- "$2" ) )
}
__perfcomp_colon ()
{
__perfcomp "$1" "$2"
if [ $preload__ltrim_colon_completions = "true" ]; then
__ltrim_colon_completions $cur
else
__perf__ltrim_colon_completions $cur
fi
}
__perf_prev_skip_opts ()
{
local i cmd_ cmds_
let i=cword-1
cmds_=$($cmd $1 --list-cmds)
prev_skip_opts=()
while [ $i -ge 0 ]; do
if [[ ${words[i]} == $1 ]]; then
return
fi
for cmd_ in $cmds_; do
if [[ ${words[i]} == $cmd_ ]]; then
prev_skip_opts=${words[i]}
return
fi
done
((i--))
done
}
__perf_main ()
{
local cmd
cmd=${words[0]}
COMPREPLY=()
# Skip options backward and find the last perf command
__perf_prev_skip_opts
# List perf subcommands or long options
if [ -z $prev_skip_opts ]; then
if [[ $cur == --* ]]; then
cmds=$($cmd --list-opts)
else
cmds=$($cmd --list-cmds)
fi
__perfcomp "$cmds" "$cur"
# List possible events for -e option
elif [[ $prev == @("-e"|"--event") &&
$prev_skip_opts == @(record|stat|top) ]]; then
evts=$($cmd list --raw-dump)
__perfcomp_colon "$evts" "$cur"
else
# List subcommands for perf commands
if [[ $prev_skip_opts == @(kvm|kmem|mem|lock|sched|
|data|help|script|test|timechart|trace) ]]; then
subcmds=$($cmd $prev_skip_opts --list-cmds)
__perfcomp_colon "$subcmds" "$cur"
fi
# List long option names
if [[ $cur == --* ]]; then
subcmd=$prev_skip_opts
__perf_prev_skip_opts $subcmd
subcmd=$subcmd" "$prev_skip_opts
opts=$($cmd $subcmd --list-opts)
__perfcomp "$opts" "$cur"
fi
fi
}
if [[ -n ${ZSH_VERSION-} ]]; then
autoload -U +X compinit && compinit
__perfcomp ()
{
emulate -L zsh
local c IFS=$' \t\n'
local -a array
for c in ${=1}; do
case $c in
--*=*|*.) ;;
*) c="$c " ;;
esac
array[${#array[@]}+1]="$c"
done
compset -P '*[=:]'
compadd -Q -S '' -a -- array && _ret=0
}
__perfcomp_colon ()
{
emulate -L zsh
local cur_="${2-$cur}"
local c IFS=$' \t\n'
local -a array
if [[ "$cur_" == *:* ]]; then
local colon_word=${cur_%"${cur_##*:}"}
fi
for c in ${=1}; do
case $c in
--*=*|*.) ;;
*) c="$c " ;;
esac
array[$#array+1]=${c#"$colon_word"}
done
compset -P '*[=:]'
compadd -Q -S '' -a -- array && _ret=0
}
_perf ()
{
local _ret=1 cur cword prev
cur=${words[CURRENT]}
prev=${words[CURRENT-1]}
let cword=CURRENT-1
emulate ksh -c __perf_main
let _ret && _default && _ret=0
return _ret
}
compdef _perf perf
return
fi
type perf &>/dev/null &&
_perf()
{
local cur words cword prev
if [ $preload_get_comp_words_by_ref = "true" ]; then
_get_comp_words_by_ref -n =: cur words cword prev
else
__perf_get_comp_words_by_ref -n =: cur words cword prev
fi
__perf_main
} &&
complete -o bashdefault -o default -o nospace -F _perf perf 2>/dev/null \
|| complete -o default -o nospace -F _perf perf