src/cdecl99.c

   1 #include <config.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <getopt.h>
   6 #include "readline.h"
   7 #include "cdecl.h"
   8
   9 static const char *progname = "cdecl99";
  10 static const char sopts[] = "VH";
  11 static const struct option lopts[] = {
  12         { "version", 0, NULL, 'V' },
  13         { "help",    0, NULL, 'H' },
  14         { 0 }
  15 };
  16
  17 static void print_version(void)
  18 {
  19         puts(PACKAGE_STRING);
  20         puts("Copyright (C) 2011 Nick Bowler.");
  21         puts("License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.");
  22         puts("This is free software: you are free to change and redistribute it.");
  23         puts("There is NO WARRANTY, to the extent permitted by law.");
  24 }
  25
  26 static void print_usage(FILE *f)
  27 {
  28         fprintf(f, "Usage: %s [options]\n", progname);
  29 }
  30
  31 static void print_help(void)
  32 {
  33         print_usage(stdout);
  34         puts("Detailed help coming soon.");
  35 }
  36
  37 static int cmd_explain(char *cmd, char *arg)
  38 {
  39         static size_t bufsz;
  40         static char *buf;
  41
  42         struct cdecl *decl;
  43         struct cdecl_declarator *d;
  44         size_t rc;
  45
  46         decl = cdecl_parse_decl(arg);
  47         if (!decl)
  48                 goto out;
  49
  50         for (d = decl->declarators; d; d = d->next) {
  51                 struct cdecl decl_tmp = {
  52                         .specifiers  = decl->specifiers,
  53                         .declarators = d,
  54                 };
  55
  56 retry:
  57                 rc = cdecl_explain(buf, bufsz, &decl_tmp);
  58                 if (rc >= bufsz) {
  59                         char *tmp;
  60
  61                         tmp = realloc(buf, rc + 1);
  62                         if (!tmp) {
  63                                 fprintf(stderr, "failed to allocate memory\n");
  64                                 goto out;
  65                         }
  66
  67                         buf = tmp;
  68                         bufsz = rc + 1;
  69                         goto retry;
  70                 }
  71
  72                 printf("%s\n", buf);
  73         }
  74 out:
  75         cdecl_free(decl);
  76         return 1;
  77 }
  78
  79 static int cmd_quit(char *cmd, char *arg)
  80 {
  81         return 0;
  82 }
  83
  84 static int cmd_help(char *cmd, char *arg);
  85
  86 static const struct command {
  87         char name[16];
  88         int (*func)(char *cmd, char *arg);
  89         const char *blurb;
  90 } commands[] = {
  91         { "explain", cmd_explain, "Explain a C declaration." },
  92         { "help",    cmd_help,    "Print this list of commands." },
  93         { "quit",    cmd_quit,    "Quit the program." },
  94         { "exit",    cmd_quit,    NULL }
  95 };
  96 static const size_t ncommands = sizeof commands / sizeof commands[0];
  97
  98 static int cmd_help(char *cmd, char *arg)
  99 {
 100         for (size_t i = 0; i < ncommands; i++) {
 101                 if (!commands[i].blurb)
 102                         continue;
 103
 104                 printf("%s -- %s\n", commands[i].name, commands[i].blurb);
 105         }
 106
 107         return 1;
 108 }
 109
 110 static int repl(void)
 111 {
 112         char *line;
 113         int ret;
 114
 115         print_version();
 116
 117         for (; (line = readline("> ")); free(line)) {
 118                 char *cmd = line + strspn(line, " \t");
 119                 char *arg = cmd  + strcspn(cmd, " \t");
 120
 121                 if (cmd[0] == '\0')
 122                         continue;
 123                 if (arg[0] != '\0')
 124                         *arg++ = '\0';
 125
 126                 for (size_t i = 0; i < ncommands; i++) {
 127                         if (strcmp(cmd, commands[i].name) != 0)
 128                                 continue;
 129
 130                         ret = commands[i].func(cmd, arg);
 131                         if (ret <= 0)
 132                                 goto out;
 133                         goto next;
 134                 }
 135
 136                 fprintf(stderr, "Undefined command: %s\n", cmd);
 137         next:
 138                 ;
 139         }
 140
 141         ret = 0;
 142 out:
 143         free(line);
 144         return ret;
 145 }
 146
 147 int main(int argc, char **argv)
 148 {
 149         int opt;
 150
 151         if (argc > 0)
 152                 progname = argv[0];
 153
 154         while ((opt = getopt_long(argc, argv, sopts, lopts, NULL)) != -1) {
 155                 switch (opt) {
 156                 case 'V':
 157                         print_version();
 158                         return EXIT_SUCCESS;
 159                 case 'H':
 160                         print_help();
 161                         return EXIT_SUCCESS;
 162                 default:
 163                         print_usage(stderr);
 164                         return EXIT_FAILURE;
 165                 }
 166         }
 167
 168         if (repl() != 0)
 169                 return EXIT_FAILURE;
 170
 171         return EXIT_SUCCESS;
 172 }