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