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