Re: [PATCH v7 1/4] perf check: introduce check subcommand

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Fri, Nov 17, 2023 at 03:04:32AM +0530, Aditya Gupta escreveu:
> Currently the presence of a feature is checked with a combination of
> perf version --build-options and greps, such as:
> 
>     perf version --build-options | grep " on .* HAVE_FEATURE"
> 
> Instead of this, introduce a subcommand "perf check --feature", with which
> scripts can test for presence of a feature, such as:
> 
>     perf check --feature HAVE_FEATURE
> 
> 'perf check --feature' command is expected to have exit status of 0 if
> feature is built-in, and 1 if it's not built-in or if feature is not known.
> 
> Multiple features can also be passed as a comma-separated list, in which
> case the exit status will be 1 only if all of the passed features are
> built-in. For example, with below command, it will have exit status of 1 only
> if both libtraceevent and libbpf_support are enabled, else 0 in all other cases
> 
>     perf check --feature libtraceevent,libbpf_support
> 
> An array 'supported_features' has also been introduced that can be used by
> other commands like 'perf version --build-options', so that new features
> can be added in one place, with the array
> 
> Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
> ---
>  tools/perf/Build                        |   1 +
>  tools/perf/Documentation/perf-check.txt |  65 +++++++++++
>  tools/perf/builtin-check.c              | 146 ++++++++++++++++++++++++
>  tools/perf/builtin.h                    |  18 +++
>  tools/perf/perf.c                       |   1 +
>  5 files changed, 231 insertions(+)
>  create mode 100644 tools/perf/Documentation/perf-check.txt
>  create mode 100644 tools/perf/builtin-check.c
> 
> diff --git a/tools/perf/Build b/tools/perf/Build
> index aa7623622834..a55a797c1b5f 100644
> --- a/tools/perf/Build
> +++ b/tools/perf/Build
> @@ -1,5 +1,6 @@
>  perf-y += builtin-bench.o
>  perf-y += builtin-annotate.o
> +perf-y += builtin-check.o
>  perf-y += builtin-config.o
>  perf-y += builtin-diff.o
>  perf-y += builtin-evlist.o
> diff --git a/tools/perf/Documentation/perf-check.txt b/tools/perf/Documentation/perf-check.txt
> new file mode 100644
> index 000000000000..dfb1dddd0ac3
> --- /dev/null
> +++ b/tools/perf/Documentation/perf-check.txt
> @@ -0,0 +1,65 @@
> +perf-check(1)
> +===============
> +
> +NAME
> +----
> +perf-check - check features in perf
> +
> +SYNOPSIS
> +--------
> +'perf check' [<options>]
> +
> +DESCRIPTION
> +-----------
> +With no options given, the 'perf check' just prints the perf version
> +on the standard output.
> +
> +If the option '--feature' is given, then status of feature is printed
> +on the standard output (unless '-q' is also passed), ie. whether it is
> +compiled-in/built-in or not.
> +Also, 'perf check --feature' returns with exit status 0 if the feature
> +is built-in, otherwise returns with exit status 1.
> +
> +OPTIONS
> +-------
> +-q::
> +		Do not print any messages or warnings
> +
> +--feature::
> +        Print whether feature(s) is compiled-in or not. A feature name/macro is
> +        required to be passed after this flag
> +
> +        Multiple features can also be passed as a comma-separated list, in which
> +        case the exit status will be 1 only if all of the passed features are
> +        compiled-in.
> +
> +        Example Usage:
> +                perf check --feature libtraceevent
> +                perf check --feature HAVE_LIBTRACEEVENT
> +                perf check --feature libtraceevent,libbpf_support
> +
> +        Supported feature names/macro:
> +                dwarf      /  HAVE_DWARF_SUPPORT
> +                dwarf_getlocations  /  HAVE_DWARF_GETLOCATIONS_SUPPORT
> +                libaudit   /  HAVE_LIBAUDIT_SUPPORT
> +                syscall_table       /  HAVE_SYSCALL_TABLE_SUPPORT
> +                libbfd     /  HAVE_LIBBFD_SUPPORT
> +                debuginfod /  HAVE_DEBUGINFOD_SUPPORT
> +                libelf     /  HAVE_LIBELF_SUPPORT
> +                libnuma    /  HAVE_LIBNUMA_SUPPORT
> +                numa_num_possible_cpus  /  HAVE_LIBNUMA_SUPPORT
> +                libperl    /  HAVE_LIBPERL_SUPPORT
> +                libpython  /  HAVE_LIBPYTHON_SUPPORT
> +                libslang   /  HAVE_SLANG_SUPPORT
> +                libcrypto  /  HAVE_LIBCRYPTO_SUPPORT
> +                libunwind  /  HAVE_LIBUNWIND_SUPPORT
> +                libdw-dwarf-unwind  /  HAVE_DWARF_SUPPORT
> +                zlib       /  HAVE_ZLIB_SUPPORT
> +                lzma       /  HAVE_LZMA_SUPPORT
> +                get_cpuid  /  HAVE_AUXTRACE_SUPPORT
> +                bpf        /  HAVE_LIBBPF_SUPPORT
> +                aio        /  HAVE_AIO_SUPPORT
> +                zstd       /  HAVE_ZSTD_SUPPORT
> +                libpfm4    /  HAVE_LIBPFM
> +                libtraceevent      /  HAVE_LIBTRACEEVENT
> +                bpf_skeletons      /  HAVE_BPF_SKEL
> diff --git a/tools/perf/builtin-check.c b/tools/perf/builtin-check.c
> new file mode 100644
> index 000000000000..25373f055121
> --- /dev/null
> +++ b/tools/perf/builtin-check.c
> @@ -0,0 +1,146 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include "builtin.h"
> +#include "color.h"
> +#include "util/debug.h"
> +#include "util/header.h"
> +#include <tools/config.h>
> +#include <stdbool.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <subcmd/parse-options.h>
> +
> +struct check {
> +	const char *feature;
> +};
> +
> +static struct check check;
> +
> +static struct option check_options[] = {
> +	OPT_STRING(0, "feature", &check.feature, NULL, "check if feature(s) is built in"),
> +	OPT_BOOLEAN('q', "quiet", &quiet, "do not show any warnings or messages"),
> +	OPT_END(),
> +};
> +
> +static const char * const check_usage[] = {
> +	"perf check [<options>]",
> +	NULL
> +};
> +
> +struct feature_support supported_features[] = {
> +	FEATURE_SUPPORT("dwarf", HAVE_DWARF_SUPPORT),
> +	FEATURE_SUPPORT("dwarf_getlocations", HAVE_DWARF_GETLOCATIONS_SUPPORT),
> +	FEATURE_SUPPORT("libaudit", HAVE_LIBAUDIT_SUPPORT),
> +	FEATURE_SUPPORT("syscall_table", HAVE_SYSCALL_TABLE_SUPPORT),
> +	FEATURE_SUPPORT("libbfd", HAVE_LIBBFD_SUPPORT),
> +	FEATURE_SUPPORT("debuginfod", HAVE_DEBUGINFOD_SUPPORT),
> +	FEATURE_SUPPORT("libelf", HAVE_LIBELF_SUPPORT),
> +	FEATURE_SUPPORT("libnuma", HAVE_LIBNUMA_SUPPORT),
> +	FEATURE_SUPPORT("numa_num_possible_cpus", HAVE_LIBNUMA_SUPPORT),
> +	FEATURE_SUPPORT("libperl", HAVE_LIBPERL_SUPPORT),
> +	FEATURE_SUPPORT("libpython", HAVE_LIBPYTHON_SUPPORT),
> +	FEATURE_SUPPORT("libslang", HAVE_SLANG_SUPPORT),
> +	FEATURE_SUPPORT("libcrypto", HAVE_LIBCRYPTO_SUPPORT),
> +	FEATURE_SUPPORT("libunwind", HAVE_LIBUNWIND_SUPPORT),
> +	FEATURE_SUPPORT("libdw-dwarf-unwind", HAVE_DWARF_SUPPORT),
> +	FEATURE_SUPPORT("zlib", HAVE_ZLIB_SUPPORT),
> +	FEATURE_SUPPORT("lzma", HAVE_LZMA_SUPPORT),
> +	FEATURE_SUPPORT("get_cpuid", HAVE_AUXTRACE_SUPPORT),
> +	FEATURE_SUPPORT("bpf", HAVE_LIBBPF_SUPPORT),
> +	FEATURE_SUPPORT("aio", HAVE_AIO_SUPPORT),
> +	FEATURE_SUPPORT("zstd", HAVE_ZSTD_SUPPORT),
> +	FEATURE_SUPPORT("libpfm4", HAVE_LIBPFM),
> +	FEATURE_SUPPORT("libtraceevent", HAVE_LIBTRACEEVENT),
> +	FEATURE_SUPPORT("bpf_skeletons", HAVE_BPF_SKEL),
> +
> +	/* this should remain at end, to know the array end */
> +	FEATURE_SUPPORT(NULL, _)
> +};
> +
> +static void on_off_print(const char *status)
> +{
> +	printf("[ ");
> +
> +	if (!strcmp(status, "OFF"))
> +		color_fprintf(stdout, PERF_COLOR_RED, "%-3s", status);
> +	else
> +		color_fprintf(stdout, PERF_COLOR_GREEN, "%-3s", status);
> +
> +	printf(" ]");
> +}
> +
> +static void status_print(const char *name, const char *macro,
> +			 const char *status)
> +{
> +	printf("%22s: ", name);
> +	on_off_print(status);
> +	printf("  # %s\n", macro);
> +}
> +
> +#define STATUS(feature)                                   \
> +do {                                                      \
> +	if (feature.is_builtin)                               \
> +		status_print(feature.name, feature.macro, "on");  \
> +	else                                                  \
> +		status_print(feature.name, feature.macro, "OFF"); \
> +} while (0)
> +
> +/**
> + * check whether "feature" is built-in with perf
> + *
> + * returns:
> + *    0: NOT built-in or Feature not known
> + *    1: Built-in
> + */
> +static int has_support(const char *feature)
> +{
> +	for (int i = 0; supported_features[i].name; ++i) {
> +		if ((strcmp(feature, supported_features[i].name) == 0) ||
> +		    (strcmp(feature, supported_features[i].macro) == 0)) {
> +			if (!quiet)
> +				STATUS(supported_features[i]);
> +			return supported_features[i].is_builtin;
> +		}
> +	}
> +
> +	if (!quiet)
> +		color_fprintf(stdout, PERF_COLOR_RED, "Feature not known: '%s'\n", feature);
> +
> +	return 0;
> +}
> +
> +int cmd_check(int argc, const char **argv)
> +{
> +	char *feature_list;
> +	char *feature_name;
> +	int feature_enabled;
> +
> +	argc = parse_options(argc, argv, check_options, check_usage,
> +			     PARSE_OPT_STOP_AT_NON_OPTION);
> +
> +	if (check.feature) {
> +		/* check.feature can be a single feature name, or a comma-separated list
> +		 * of feature names.
> +		 * eg. check.feature can be "libtraceevent" or
> +		 * "libtraceevent,libbpf_support" etc
> +		 *
> +		 * In case of a comma-separated list, feature_enabled will be 1, only if
> +		 * all features passed in the string are supported
> +		 * Note that check.feature will get modified due to strtok and str_trim
> +		 */
> +		feature_enabled = 1;
> +		feature_list = malloc((strlen(check.feature)+1) * sizeof(char));

malloc can fail, do error checking here.

> +		strncpy(feature_list, check.feature, strlen(check.feature)+1);


> +		feature_name = strtok(feature_list, ",");
> +
> +		while (feature_name) {
> +			feature_enabled &= has_support(feature_name);
> +			feature_name = strtok(NULL, ",");
> +		}
> +
> +		free(feature_list);
> +
> +		return !feature_enabled;
> +	}
> +
> +	return 0;
> +}
> diff --git a/tools/perf/builtin.h b/tools/perf/builtin.h
> index f2ab5bae2150..9f895981bc9e 100644
> --- a/tools/perf/builtin.h
> +++ b/tools/perf/builtin.h
> @@ -2,6 +2,23 @@
>  #ifndef BUILTIN_H
>  #define BUILTIN_H
>  
> +#include <stddef.h>
> +#include <linux/compiler.h>
> +#include <tools/config.h>
> +
> +struct feature_support {
> +	const char *name;
> +	const char *macro;
> +	int is_builtin;
> +};
> +
> +#define FEATURE_SUPPORT(name_, macro_) { \
> +	.name = name_,                       \
> +	.macro = #macro_,                    \
> +	.is_builtin = IS_BUILTIN(macro_) }
> +
> +extern struct feature_support supported_features[];
> +
>  void list_common_cmds_help(void);
>  const char *help_unknown_cmd(const char *cmd);
>  
> @@ -9,6 +26,7 @@ int cmd_annotate(int argc, const char **argv);
>  int cmd_bench(int argc, const char **argv);
>  int cmd_buildid_cache(int argc, const char **argv);
>  int cmd_buildid_list(int argc, const char **argv);
> +int cmd_check(int argc, const char **argv);
>  int cmd_config(int argc, const char **argv);
>  int cmd_c2c(int argc, const char **argv);
>  int cmd_diff(int argc, const char **argv);
> diff --git a/tools/perf/perf.c b/tools/perf/perf.c
> index d3fc8090413c..6514f4121c49 100644
> --- a/tools/perf/perf.c
> +++ b/tools/perf/perf.c
> @@ -50,6 +50,7 @@ static struct cmd_struct commands[] = {
>  	{ "archive",	NULL,	0 },
>  	{ "buildid-cache", cmd_buildid_cache, 0 },
>  	{ "buildid-list", cmd_buildid_list, 0 },
> +	{ "check",	cmd_check,	0 },
>  	{ "config",	cmd_config,	0 },
>  	{ "c2c",	cmd_c2c,	0 },
>  	{ "diff",	cmd_diff,	0 },
> -- 
> 2.41.0
> 

-- 

- Arnaldo