git.ozlabs.org Git - ccan/blob - tools/configurator/configurator.c

   1 /* Simple tool to create config.h.
   2  * Would be much easier with ccan modules, but deliberately standalone. */
   3 #include <stdio.h>
   4 #include <stdbool.h>
   5 #include <stdlib.h>
   6 #include <unistd.h>
   7 #include <err.h>
   8 #include <sys/types.h>
   9 #include <sys/wait.h>
  10 #include <sys/stat.h>
  11 #include <fcntl.h>
  12 #include <string.h>
  13
  14 #define DEFAULT_COMPILER "cc"
  15 #define DEFAULT_FLAGS "-g -Wall -Wundef -Wmissing-prototypes -Wmissing-declarations -Wstrict-prototypes -Wold-style-definition"
  16
  17 #define OUTPUT_FILE "configurator.out"
  18 #define INPUT_FILE "configuratortest.c"
  19
  20 static int verbose;
  21
  22 enum test_style {
  23         OUTSIDE_MAIN            = 0x1,
  24         DEFINES_FUNC            = 0x2,
  25         INSIDE_MAIN             = 0x4,
  26         DEFINES_EVERYTHING      = 0x8,
  27         EXECUTE                 = 0x8000
  28 };
  29
  30 struct test {
  31         const char *name;
  32         enum test_style style;
  33         const char *depends;
  34         const char *fragment;
  35         bool done;
  36         bool answer;
  37 };
  38
  39 static struct test tests[] = {
  40         { "HAVE_ALIGNOF", INSIDE_MAIN, NULL,
  41           "return __alignof__(double) > 0 ? 0 : 1;" },
  42         { "HAVE_ASPRINTF", DEFINES_FUNC, NULL,
  43           "#define _GNU_SOURCE\n"
  44           "#include <stdio.h>\n"
  45           "static char *func(int x) {"
  46           "     char *p;\n"
  47           "     if (asprintf(&p, \"%u\", x) == -1) p = NULL;"
  48           "     return p;\n"
  49           "}" },
  50         { "HAVE_ATTRIBUTE_COLD", DEFINES_FUNC, NULL,
  51           "static int __attribute__((cold)) func(int x) { return x; }" },
  52         { "HAVE_ATTRIBUTE_CONST", DEFINES_FUNC, NULL,
  53           "static int __attribute__((const)) func(int x) { return x; }" },
  54         { "HAVE_ATTRIBUTE_MAY_ALIAS", OUTSIDE_MAIN, NULL,
  55           "typedef short __attribute__((__may_alias__)) short_a;" },
  56         { "HAVE_ATTRIBUTE_NORETURN", DEFINES_FUNC, NULL,
  57           "#include <stdlib.h>\n"
  58           "static void __attribute__((noreturn)) func(int x) { exit(x); }" },
  59         { "HAVE_ATTRIBUTE_PRINTF", DEFINES_FUNC, NULL,
  60           "static void __attribute__((format(__printf__, 1, 2))) func(const char *fmt, ...) { }" },
  61         { "HAVE_ATTRIBUTE_UNUSED", OUTSIDE_MAIN, NULL,
  62           "static int __attribute__((unused)) func(int x) { return x; }" },
  63         { "HAVE_ATTRIBUTE_USED", OUTSIDE_MAIN, NULL,
  64           "static int __attribute__((used)) func(int x) { return x; }" },
  65         { "HAVE_BIG_ENDIAN", INSIDE_MAIN|EXECUTE, NULL,
  66           "union { int i; char c[sizeof(int)]; } u;\n"
  67           "u.i = 0x01020304;\n"
  68           "return u.c[0] == 0x01 && u.c[1] == 0x02 && u.c[2] == 0x03 && u.c[3] == 0x04 ? 0 : 1;" },
  69         { "HAVE_BSWAP_64", DEFINES_FUNC, "HAVE_BYTESWAP_H",
  70           "#include <byteswap.h>\n"
  71           "static int func(int x) { return bswap_64(x); }" },
  72         { "HAVE_BUILTIN_CHOOSE_EXPR", INSIDE_MAIN, NULL,
  73           "return __builtin_choose_expr(1, 0, \"garbage\");" },
  74         { "HAVE_BUILTIN_CLZ", INSIDE_MAIN, NULL,
  75           "return __builtin_clz(1) == (sizeof(int)*8 - 1) ? 0 : 1;" },
  76         { "HAVE_BUILTIN_CLZL", INSIDE_MAIN, NULL,
  77           "return __builtin_clzl(1) == (sizeof(long)*8 - 1) ? 0 : 1;" },
  78         { "HAVE_BUILTIN_CLZLL", INSIDE_MAIN, NULL,
  79           "return __builtin_clzll(1) == (sizeof(long long)*8 - 1) ? 0 : 1;" },
  80         { "HAVE_BUILTIN_CONSTANT_P", INSIDE_MAIN, NULL,
  81           "return __builtin_constant_p(1) ? 0 : 1;" },
  82         { "HAVE_BUILTIN_EXPECT", INSIDE_MAIN, NULL,
  83           "return __builtin_expect(argc == 1, 1) ? 0 : 1;" },
  84         { "HAVE_BUILTIN_FFSL", INSIDE_MAIN, NULL,
  85           "return __builtin_ffsl(0L) == 0 ? 0 : 1;" },
  86         { "HAVE_BUILTIN_FFSLL", INSIDE_MAIN, NULL,
  87           "return __builtin_ffsll(0LL) == 0 ? 0 : 1;" },
  88         { "HAVE_BUILTIN_POPCOUNTL", INSIDE_MAIN, NULL,
  89           "return __builtin_popcountl(255L) == 8 ? 0 : 1;" },
  90         { "HAVE_BUILTIN_TYPES_COMPATIBLE_P", INSIDE_MAIN, NULL,
  91           "return __builtin_types_compatible_p(char *, int) ? 1 : 0;" },
  92         { "HAVE_BYTESWAP_H", OUTSIDE_MAIN, NULL,
  93           "#include <byteswap.h>\n" },
  94         { "HAVE_COMPOUND_LITERALS", INSIDE_MAIN, NULL,
  95           "char **foo = (char *[]) { \"x\", \"y\", \"z\" };\n"
  96           "return foo[0] ? 0 : 1;" },
  97         { "HAVE_FOR_LOOP_DECLARATION", INSIDE_MAIN, NULL,
  98           "for (int i = 0; i < argc; i++) { return 0; };\n"
  99           "return 1;" },
 100         { "HAVE_FLEXIBLE_ARRAY_MEMBER", OUTSIDE_MAIN, NULL,
 101           "struct foo { unsigned int x; int arr[]; };" },
 102         { "HAVE_GETPAGESIZE", DEFINES_FUNC, NULL,
 103           "#include <unistd.h>\n"
 104           "static int func(void) { return getpagesize(); }" },
 105         { "HAVE_LITTLE_ENDIAN", INSIDE_MAIN|EXECUTE, NULL,
 106           "union { int i; char c[sizeof(int)]; } u;\n"
 107           "u.i = 0x01020304;\n"
 108           "return u.c[0] == 0x04 && u.c[1] == 0x03 && u.c[2] == 0x02 && u.c[3] == 0x01 ? 0 : 1;" },
 109         { "HAVE_MMAP", DEFINES_FUNC, NULL,
 110           "#include <sys/mman.h>\n"
 111           "static void *func(int fd) {\n"
 112           "     return mmap(0, 65536, PROT_READ, MAP_SHARED, fd, 0);\n"
 113           "}" },
 114         { "HAVE_NESTED_FUNCTIONS", DEFINES_FUNC, NULL,
 115           "void (*func(int val))(int);\n"
 116           "void (*func(int val))(int) {\n"
 117           "     auto void add(int val2);\n"
 118           "     void add(int val2) { val += val2; }\n"
 119           "     return add;\n"
 120           "}\n" },
 121         { "HAVE_STACK_GROWS_UPWARDS", DEFINES_EVERYTHING|EXECUTE, NULL,
 122           "static long nest(const void *base, unsigned int i)\n"
 123           "{\n"
 124           "     if (i == 0)\n"
 125           "             return (const char *)&i - (const char *)base;\n"
 126           "     return nest(base, i-1);\n"
 127           "}\n"
 128           "int main(int argc, char *argv[]) {\n"
 129           "     return (nest(&argc, argc) > 0) ? 0 : 1\n;"
 130           "}\n" },
 131         { "HAVE_STATEMENT_EXPR", INSIDE_MAIN, NULL,
 132           "return ({ int x = argc; x == argc ? 0 : 1; });" },
 133         { "HAVE_TYPEOF", INSIDE_MAIN, NULL,
 134           "__typeof__(argc) i; i = argc; return i == argc ? 0 : 1;" },
 135         { "HAVE_UTIME", DEFINES_FUNC, NULL,
 136           "#include <sys/types.h>\n"
 137           "#include <utime.h>\n"
 138           "static int func(const char *filename) {\n"
 139           "     struct utimbuf times = { 0 };\n"
 140           "     return utime(filename, &times);\n"
 141           "}" },
 142         { "HAVE_WARN_UNUSED_RESULT", DEFINES_FUNC, NULL,
 143           "#include <sys/types.h>\n"
 144           "#include <utime.h>\n"
 145           "static __attribute__((warn_unused_result)) int func(int i) {\n"
 146           "     return i + 1;\n"
 147           "}" },
 148 };
 149
 150 static char *grab_fd(int fd)
 151 {
 152         int ret;
 153         size_t max, size = 0;
 154         char *buffer;
 155
 156         max = 16384;
 157         buffer = malloc(max+1);
 158         while ((ret = read(fd, buffer + size, max - size)) > 0) {
 159                 size += ret;
 160                 if (size == max)
 161                         buffer = realloc(buffer, max *= 2);
 162         }
 163         if (ret < 0)
 164                 err(1, "reading from command");
 165         buffer[size] = '\0';
 166         return buffer;
 167 }
 168
 169 static char *run(const char *cmd, int *exitstatus)
 170 {
 171         pid_t pid;
 172         int p[2];
 173         char *ret;
 174         int status;
 175
 176         if (pipe(p) != 0)
 177                 err(1, "creating pipe");
 178
 179         pid = fork();
 180         if (pid == -1)
 181                 err(1, "forking");
 182
 183         if (pid == 0) {
 184                 if (dup2(p[1], STDOUT_FILENO) != STDOUT_FILENO
 185                     || dup2(p[1], STDERR_FILENO) != STDERR_FILENO
 186                     || close(p[0]) != 0
 187                     || close(STDIN_FILENO) != 0
 188                     || open("/dev/null", O_RDONLY) != STDIN_FILENO)
 189                         exit(128);
 190
 191                 status = system(cmd);
 192                 if (WIFEXITED(status))
 193                         exit(WEXITSTATUS(status));
 194                 /* Here's a hint... */
 195                 exit(128 + WTERMSIG(status));
 196         }
 197
 198         close(p[1]);
 199         ret = grab_fd(p[0]);
 200         /* This shouldn't fail... */
 201         if (waitpid(pid, &status, 0) != pid)
 202                 err(1, "Failed to wait for child");
 203         close(p[0]);
 204         if (WIFEXITED(status))
 205                 *exitstatus = WEXITSTATUS(status);
 206         else
 207                 *exitstatus = -WTERMSIG(status);
 208         return ret;
 209 }
 210
 211 static char *connect_args(char *argv[], const char *extra)
 212 {
 213         unsigned int i, len = strlen(extra) + 1;
 214         char *ret;
 215
 216         for (i = 1; argv[i]; i++)
 217                 len += 1 + strlen(argv[i]);
 218
 219         ret = malloc(len);
 220         len = 0;
 221         for (i = 1; argv[i]; i++) {
 222                 strcpy(ret + len, argv[i]);
 223                 len += strlen(argv[i]);
 224                 ret[len++] = ' ';
 225         }
 226         strcpy(ret + len, extra);
 227         return ret;
 228 }
 229
 230 static struct test *find_test(const char *name)
 231 {
 232         unsigned int i;
 233
 234         for (i = 0; i < sizeof(tests)/sizeof(tests[0]); i++) {
 235                 if (strcmp(tests[i].name, name) == 0)
 236                         return &tests[i];
 237         }
 238         abort();
 239 }
 240
 241 #define PRE_BOILERPLATE "/* Test program generated by configurator. */\n"
 242 #define MAIN_START_BOILERPLATE "int main(int argc, char *argv[]) {\n"
 243 #define USE_FUNC_BOILERPLATE "(void)func;\n"
 244 #define MAIN_BODY_BOILERPLATE "return 0;\n"
 245 #define MAIN_END_BOILERPLATE "}\n"
 246
 247 static bool run_test(const char *cmd, struct test *test)
 248 {
 249         char *output;
 250         FILE *outf;
 251         int status;
 252
 253         if (test->done)
 254                 return test->answer;
 255
 256         if (test->depends && !run_test(cmd, find_test(test->depends))) {
 257                 test->answer = false;
 258                 test->done = true;
 259                 return test->answer;
 260         }
 261
 262         outf = fopen(INPUT_FILE, "w");
 263         if (!outf)
 264                 err(1, "creating %s", INPUT_FILE);
 265
 266         fprintf(outf, "%s", PRE_BOILERPLATE);
 267         switch (test->style & ~EXECUTE) {
 268         case INSIDE_MAIN:
 269                 fprintf(outf, "%s", MAIN_START_BOILERPLATE);
 270                 fprintf(outf, "%s", test->fragment);
 271                 fprintf(outf, "%s", MAIN_END_BOILERPLATE);
 272                 break;
 273         case OUTSIDE_MAIN:
 274                 fprintf(outf, "%s", test->fragment);
 275                 fprintf(outf, "%s", MAIN_START_BOILERPLATE);
 276                 fprintf(outf, "%s", MAIN_BODY_BOILERPLATE);
 277                 fprintf(outf, "%s", MAIN_END_BOILERPLATE);
 278                 break;
 279         case DEFINES_FUNC:
 280                 fprintf(outf, "%s", test->fragment);
 281                 fprintf(outf, "%s", MAIN_START_BOILERPLATE);
 282                 fprintf(outf, "%s", USE_FUNC_BOILERPLATE);
 283                 fprintf(outf, "%s", MAIN_BODY_BOILERPLATE);
 284                 fprintf(outf, "%s", MAIN_END_BOILERPLATE);
 285                 break;
 286         case DEFINES_EVERYTHING:
 287                 fprintf(outf, "%s", test->fragment);
 288                 break;
 289         default:
 290                 abort();
 291
 292         }
 293         fclose(outf);
 294
 295         if (verbose > 1)
 296                 if (system("cat " INPUT_FILE) == -1);
 297
 298         output = run(cmd, &status);
 299         if (status != 0 || strstr(output, "warning")) {
 300                 if (verbose)
 301                         printf("Compile %s for %s, status %i: %s\n",
 302                                status ? "fail" : "warning",
 303                                test->name, status, output);
 304                 if (test->style & EXECUTE)
 305                         errx(1, "Test for %s did not compile:\n%s",
 306                              test->name, output);
 307                 test->answer = false;
 308                 free(output);
 309         } else {
 310                 /* Compile succeeded. */
 311                 free(output);
 312                 /* We run INSIDE_MAIN tests for sanity checking. */
 313                 if ((test->style & EXECUTE) || (test->style & INSIDE_MAIN)) {
 314                         output = run("./" OUTPUT_FILE, &status);
 315                         if (!(test->style & EXECUTE) && status != 0)
 316                                 errx(1, "Test for %s failed with %i:\n%s",
 317                                      test->name, status, output);
 318                         if (verbose && status)
 319                                 printf("%s exited %i\n", test->name, status);
 320                         free(output);
 321                 }
 322                 test->answer = (status == 0);
 323         }
 324         test->done = true;
 325         return test->answer;
 326 }
 327
 328 int main(int argc, char *argv[])
 329 {
 330         char *cmd;
 331         char *default_args[] = { "", DEFAULT_COMPILER, DEFAULT_FLAGS, NULL };
 332         unsigned int i;
 333
 334         if (argc > 1) {
 335                 if (strcmp(argv[1], "--help") == 0) {
 336                         printf("Usage: configurator [-v] [<compiler> <flags>...]\n"
 337                                "  <compiler> <flags> will have \"-o <outfile> <infile.c>\" appended\n"
 338                                "Default: %s %s\n",
 339                                DEFAULT_COMPILER, DEFAULT_FLAGS);
 340                         exit(0);
 341                 }
 342                 if (strcmp(argv[1], "-v") == 0) {
 343                         argc--;
 344                         argv++;
 345                         verbose = 1;
 346                 } else if (strcmp(argv[1], "-vv") == 0) {
 347                         argc--;
 348                         argv++;
 349                         verbose = 2;
 350                 }
 351         }
 352
 353         if (argc == 1)
 354                 argv = default_args;
 355
 356         cmd = connect_args(argv, "-o " OUTPUT_FILE " " INPUT_FILE);
 357         for (i = 0; i < sizeof(tests)/sizeof(tests[0]); i++)
 358                 run_test(cmd, &tests[i]);
 359
 360         unlink(OUTPUT_FILE);
 361         unlink(INPUT_FILE);
 362
 363         cmd[strlen(cmd) - strlen(" -o " OUTPUT_FILE " " INPUT_FILE)] = '\0';
 364         printf("/* Generated by CCAN configurator */\n"
 365                "#ifndef CCAN_CONFIG_H\n"
 366                "#define CCAN_CONFIG_H\n");
 367         printf("#define _GNU_SOURCE /* Always use GNU extensions. */\n");
 368         printf("#define CCAN_COMPILER \"%s\"\n", argv[1]);
 369         printf("#define CCAN_CFLAGS \"%s\"\n\n", cmd + strlen(argv[1]) + 1);
 370         for (i = 0; i < sizeof(tests)/sizeof(tests[0]); i++)
 371                 printf("#define %s %u\n", tests[i].name, tests[i].answer);
 372         printf("#endif /* CCAN_CONFIG_H */\n");
 373         return 0;
 374 }