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