1 /*
2 * Copyright 2022 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "argp.h"
18
19 #include <getopt.h>
20 #include <stdio.h>
21 #include <sysexits.h>
22
23 #include <algorithm>
24 #include <sstream>
25 #include <string>
26 #include <vector>
27
argp_parse(const struct argp * argp,int argc,char ** argv,int,void *,void * input)28 extern "C" error_t argp_parse(const struct argp *argp, int argc, char **argv, int /*unused*/,
29 void * /* unused */, void *input) {
30 int longindex;
31 std::string optstring;
32 std::vector<struct option> optvec;
33
34 // process argp_option array for use with getopt_long
35 for (const struct argp_option *opt = argp->options; opt->name || opt->docstring; ++opt) {
36 if (opt->key && isprint(opt->key)) {
37 optstring += opt->key;
38 if (opt->argname) optstring += ':';
39 }
40
41 if (opt->name) {
42 optvec.push_back({ .name = opt->name, .has_arg = opt->argname ? 1 : 0,
43 .flag = opt->key ? nullptr : &longindex, .val = opt->key });
44 }
45 }
46 int longhelp = 0;
47 optvec.push_back({ .name = "help", .has_arg = 0, .flag = &longhelp, .val = 1 });
48 optvec.push_back({});
49
50 int opt;
51 while ((opt = getopt_long(argc, argv, optstring.c_str(), optvec.data(), &longindex)) != -1) {
52 struct argp_state state = { .input = input, .argp = argp };
53 if (!opt) {
54 if (longhelp) argp_state_help(&state, stdout, ARGP_HELP_STD_HELP);
55 return EINVAL;
56 }
57 error_t ret = argp->parser(opt, optarg, &state);
58 if (ret) return ret;
59 }
60
61 // Handle positional arguments
62 if (optind < argc) {
63 for (int idx = optind; idx < argc; idx++) {
64 struct argp_state state = { .input = input, .argp = argp, .arg_num = idx - optind };
65 const error_t ret = argp->parser(ARGP_KEY_ARG, argv[idx], &state);
66 if (ret) return ret;
67 }
68 }
69 struct argp_state state = {.input = input, .argp = argp};
70 const error_t ret = argp->parser(ARGP_KEY_END, 0, &state);
71 // Not all tools expect ARGP_KEY_END, so ARGP_ERR_UNKNOWN here is benign
72 if (ret && ret != ARGP_ERR_UNKNOWN) return ret;
73 return 0;
74 }
75
76
argp_usage(struct argp_state * state)77 extern "C" void argp_usage(struct argp_state* state) {
78 fprintf(stderr, "%s", state->argp->doc);
79 exit(EX_USAGE);
80 }
81
argp_state_help(struct argp_state * state,FILE * fd,int)82 extern "C" void argp_state_help(struct argp_state* state, FILE *fd, int /* unused */) {
83 constexpr size_t kFlagOffset = 2, kNameOffset = 6, kDocstringOffset = 29;
84
85 fprintf(fd, "%s\n", state->argp->doc);
86 for (const struct argp_option *opt = state->argp->options; opt->name || opt->docstring; ++opt) {
87 // Skip hidden arguments and empty entries in the argp_option array
88 if (opt->n == OPTION_HIDDEN || (opt->docstring && opt->docstring[0] == '\0')) continue;
89
90 std::string s(kFlagOffset, ' ');
91
92 // Append short argument form (e.g. "-p,") if applicable, then whitespace
93 if (opt->key && isprint(opt->key)) {
94 s.append("-");
95 s.append(1, (char)opt->key);
96 s.append(",");
97 }
98 s.append(kNameOffset - s.length(), ' ');
99
100 // Append long argument form (e.g. "--pid=PID") or whitespace
101 if (opt->name) {
102 s.append("--");
103 s.append(opt->name);
104 if (opt->argname) {
105 s.append("=");
106 s.append(opt->argname);
107 }
108 }
109 if (s.length() < kDocstringOffset) {
110 s.append(kDocstringOffset - s.length(), ' ');
111 } else {
112 s.append(" ");
113 }
114
115 // Append docstring
116 s.append(opt->docstring);
117 s.append("\n");
118 fprintf(fd, "%s", s.c_str());
119 }
120 exit(EX_OK);
121 }
122