Re: [PATCH] perf kvm: introduce --list-cmds for use by scripts

From: David Ahern
Date: Tue Mar 04 2014 - 20:00:41 EST


On 3/3/14, 6:26 PM, Ramkumar Ramachandra wrote:
Introduce

$ perf kvm --list-cmds

to dump a raw list of commands for use by the completion script. In
order to do this, introduce parse_options_subcommand() for handling
subcommands as a special case in the parse-options machinery.

Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Ramkumar Ramachandra <artagnon@xxxxxxxxx>

Looks ok to me. Jiri?

David

---
Does this example justify the creation of parse_options_subcommand()?
Initializing the usagestr to { NULL, NULL } and passing it to
parse_options_subcommand() isn't intuitive -- what can we do about
that?

tools/perf/builtin-kvm.c | 12 +++++-------
tools/perf/perf-completion.sh | 2 +-
tools/perf/util/parse-options.c | 37 +++++++++++++++++++++++++++++++++----
tools/perf/util/parse-options.h | 8 +++++++-
4 files changed, 46 insertions(+), 13 deletions(-)

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index a735051..21c164b 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -1691,17 +1691,15 @@ int cmd_kvm(int argc, const char **argv, const char *prefix __maybe_unused)
OPT_END()
};

-
- const char * const kvm_usage[] = {
- "perf kvm [<options>] {top|record|report|diff|buildid-list|stat}",
- NULL
- };
+ const char *const kvm_subcommands[] = { "top", "record", "report", "diff",
+ "buildid-list", "stat", NULL };
+ const char *kvm_usage[] = { NULL, NULL };

perf_host = 0;
perf_guest = 1;

- argc = parse_options(argc, argv, kvm_options, kvm_usage,
- PARSE_OPT_STOP_AT_NON_OPTION);
+ argc = parse_options_subcommand(argc, argv, kvm_options, kvm_subcommands, kvm_usage,
+ PARSE_OPT_STOP_AT_NON_OPTION);
if (!argc)
usage_with_options(kvm_usage, kvm_options);

diff --git a/tools/perf/perf-completion.sh b/tools/perf/perf-completion.sh
index 496e2ab..ae3a576 100644
--- a/tools/perf/perf-completion.sh
+++ b/tools/perf/perf-completion.sh
@@ -123,7 +123,7 @@ __perf_main ()
__perfcomp_colon "$evts" "$cur"
# List subcommands for 'perf kvm'
elif [[ $prev == "kvm" ]]; then
- subcmds="top record report diff buildid-list stat"
+ subcmds=$($cmd $prev --list-cmds)
__perfcomp_colon "$subcmds" "$cur"
# List long option names
elif [[ $cur == --* ]]; then
diff --git a/tools/perf/util/parse-options.c b/tools/perf/util/parse-options.c
index d22e3f8..bf48092 100644
--- a/tools/perf/util/parse-options.c
+++ b/tools/perf/util/parse-options.c
@@ -407,7 +407,9 @@ int parse_options_step(struct parse_opt_ctx_t *ctx,
if (internal_help && !strcmp(arg + 2, "help"))
return usage_with_options_internal(usagestr, options, 0);
if (!strcmp(arg + 2, "list-opts"))
- return PARSE_OPT_LIST;
+ return PARSE_OPT_LIST_OPTS;
+ if (!strcmp(arg + 2, "list-cmds"))
+ return PARSE_OPT_LIST_SUBCMDS;
switch (parse_long_opt(ctx, arg + 2, options)) {
case -1:
return parse_options_usage(usagestr, options, arg + 2, 0);
@@ -433,25 +435,45 @@ int parse_options_end(struct parse_opt_ctx_t *ctx)
return ctx->cpidx + ctx->argc;
}

-int parse_options(int argc, const char **argv, const struct option *options,
- const char * const usagestr[], int flags)
+int parse_options_subcommand(int argc, const char **argv, const struct option *options,
+ const char *const subcommands[], const char *usagestr[], int flags)
{
struct parse_opt_ctx_t ctx;

perf_header__set_cmdline(argc, argv);

+ /* build usage string if it's not provided */
+ if (subcommands && !usagestr[0]) {
+ struct strbuf buf = STRBUF_INIT;
+
+ strbuf_addf(&buf, "perf %s [<options>] {", argv[0]);
+ for (int i = 0; subcommands[i]; i++) {
+ if (i)
+ strbuf_addstr(&buf, "|");
+ strbuf_addstr(&buf, subcommands[i]);
+ }
+ strbuf_addstr(&buf, "}");
+
+ usagestr[0] = strdup(buf.buf);
+ strbuf_release(&buf);
+ }
+
parse_options_start(&ctx, argc, argv, flags);
switch (parse_options_step(&ctx, options, usagestr)) {
case PARSE_OPT_HELP:
exit(129);
case PARSE_OPT_DONE:
break;
- case PARSE_OPT_LIST:
+ case PARSE_OPT_LIST_OPTS:
while (options->type != OPTION_END) {
printf("--%s ", options->long_name);
options++;
}
exit(130);
+ case PARSE_OPT_LIST_SUBCMDS:
+ for (int i = 0; subcommands[i]; i++)
+ printf("%s ", subcommands[i]);
+ exit(130);
default: /* PARSE_OPT_UNKNOWN */
if (ctx.argv[0][1] == '-') {
error("unknown option `%s'", ctx.argv[0] + 2);
@@ -464,6 +486,13 @@ int parse_options(int argc, const char **argv, const struct option *options,
return parse_options_end(&ctx);
}

+int parse_options(int argc, const char **argv, const struct option *options,
+ const char * const usagestr[], int flags)
+{
+ return parse_options_subcommand(argc, argv, options, NULL,
+ (const char **) usagestr, flags);
+}
+
#define USAGE_OPTS_WIDTH 24
#define USAGE_GAP 2

diff --git a/tools/perf/util/parse-options.h b/tools/perf/util/parse-options.h
index cbf0149..d8dac8a 100644
--- a/tools/perf/util/parse-options.h
+++ b/tools/perf/util/parse-options.h
@@ -140,6 +140,11 @@ extern int parse_options(int argc, const char **argv,
const struct option *options,
const char * const usagestr[], int flags);

+extern int parse_options_subcommand(int argc, const char **argv,
+ const struct option *options,
+ const char *const subcommands[],
+ const char *usagestr[], int flags);
+
extern NORETURN void usage_with_options(const char * const *usagestr,
const struct option *options);

@@ -148,7 +153,8 @@ extern NORETURN void usage_with_options(const char * const *usagestr,
enum {
PARSE_OPT_HELP = -1,
PARSE_OPT_DONE,
- PARSE_OPT_LIST,
+ PARSE_OPT_LIST_OPTS,
+ PARSE_OPT_LIST_SUBCMDS,
PARSE_OPT_UNKNOWN,
};



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/