android13/external/bcc/libbpf-tools/android/argp.cpp

122 lines
4.1 KiB
C++

/*
* Copyright 2022 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "argp.h"
#include <getopt.h>
#include <stdio.h>
#include <sysexits.h>
#include <algorithm>
#include <sstream>
#include <string>
#include <vector>
extern "C" error_t argp_parse(const struct argp *argp, int argc, char **argv, int /*unused*/,
void * /* unused */, void *input) {
int longindex;
std::string optstring;
std::vector<struct option> optvec;
// process argp_option array for use with getopt_long
for (const struct argp_option *opt = argp->options; opt->name || opt->docstring; ++opt) {
if (opt->key && isprint(opt->key)) {
optstring += opt->key;
if (opt->argname) optstring += ':';
}
if (opt->name) {
optvec.push_back({ .name = opt->name, .has_arg = opt->argname ? 1 : 0,
.flag = opt->key ? nullptr : &longindex, .val = opt->key });
}
}
int longhelp = 0;
optvec.push_back({ .name = "help", .has_arg = 0, .flag = &longhelp, .val = 1 });
optvec.push_back({});
int opt;
while ((opt = getopt_long(argc, argv, optstring.c_str(), optvec.data(), &longindex)) != -1) {
struct argp_state state = { .input = input, .argp = argp };
if (!opt) {
if (longhelp) argp_state_help(&state, stdout, ARGP_HELP_STD_HELP);
return EINVAL;
}
error_t ret = argp->parser(opt, optarg, &state);
if (ret) return ret;
}
// Handle positional arguments
if (optind < argc) {
for (int idx = optind; idx < argc; idx++) {
struct argp_state state = { .input = input, .argp = argp, .arg_num = idx - optind };
const error_t ret = argp->parser(ARGP_KEY_ARG, argv[idx], &state);
if (ret) return ret;
}
}
struct argp_state state = {.input = input, .argp = argp};
const error_t ret = argp->parser(ARGP_KEY_END, 0, &state);
// Not all tools expect ARGP_KEY_END, so ARGP_ERR_UNKNOWN here is benign
if (ret && ret != ARGP_ERR_UNKNOWN) return ret;
return 0;
}
extern "C" void argp_usage(struct argp_state* state) {
fprintf(stderr, "%s", state->argp->doc);
exit(EX_USAGE);
}
extern "C" void argp_state_help(struct argp_state* state, FILE *fd, int /* unused */) {
constexpr size_t kFlagOffset = 2, kNameOffset = 6, kDocstringOffset = 29;
fprintf(fd, "%s\n", state->argp->doc);
for (const struct argp_option *opt = state->argp->options; opt->name || opt->docstring; ++opt) {
// Skip hidden arguments and empty entries in the argp_option array
if (opt->n == OPTION_HIDDEN || (opt->docstring && opt->docstring[0] == '\0')) continue;
std::string s(kFlagOffset, ' ');
// Append short argument form (e.g. "-p,") if applicable, then whitespace
if (opt->key && isprint(opt->key)) {
s.append("-");
s.append(1, (char)opt->key);
s.append(",");
}
s.append(kNameOffset - s.length(), ' ');
// Append long argument form (e.g. "--pid=PID") or whitespace
if (opt->name) {
s.append("--");
s.append(opt->name);
if (opt->argname) {
s.append("=");
s.append(opt->argname);
}
}
if (s.length() < kDocstringOffset) {
s.append(kDocstringOffset - s.length(), ' ');
} else {
s.append(" ");
}
// Append docstring
s.append(opt->docstring);
s.append("\n");
fprintf(fd, "%s", s.c_str());
}
exit(EX_OK);
}