toolchain/toolchain-external/ext-toolchain-wrapper.c

   1 /**
   2  * Buildroot wrapper for external toolchains. This simply executes the real
   3  * toolchain with a number of arguments (sysroot/arch/..) hardcoded,
   4  * to ensure the external toolchain uses the correct configuration.
   5  * The hardcoded path arguments are defined relative to the actual location
   6  * of the binary.
   7  *
   8  * (C) 2011 Peter Korsgaard <jacmet@sunsite.dk>
   9  * (C) 2011 Daniel Nyström <daniel.nystrom@timeterminal.se>
  10  * (C) 2012 Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
  11  * (C) 2013 Spenser Gilliland <spenser@gillilanding.com>
  12  *
  13  * This file is licensed under the terms of the GNU General Public License
  14  * version 2.  This program is licensed "as is" without any warranty of any
  15  * kind, whether express or implied.
  16  */
  17
  18 #include <stdio.h>
  19 #include <string.h>
  20 #include <limits.h>
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23
  24 static char path[PATH_MAX];
  25 static char sysroot[PATH_MAX];
  26
  27 /**
  28  * GCC errors out with certain combinations of arguments (examples are
  29  * -mfloat-abi={hard|soft} and -m{little|big}-endian), so we have to ensure
  30  * that we only pass the predefined one to the real compiler if the inverse
  31  * option isn't in the argument list.
  32  * This specifies the worst case number of extra arguments we might pass
  33  * Currently, we have:
  34  *      -mfloat-abi=
  35  *      -march=
  36  *      -mtune=
  37  *      -mcpu=
  38  */
  39 #define EXCLUSIVE_ARGS  4
  40
  41 static char *predef_args[] = {
  42         path,
  43         "--sysroot", sysroot,
  44 #ifdef BR_ABI
  45         "-mabi=" BR_ABI,
  46 #endif
  47 #ifdef BR_FPU
  48         "-mfpu=" BR_FPU,
  49 #endif
  50 #ifdef BR_SOFTFLOAT
  51         "-msoft-float",
  52 #endif /* BR_SOFTFLOAT */
  53 #ifdef BR_MODE
  54         "-m" BR_MODE,
  55 #endif
  56 #ifdef BR_64
  57         "-m64",
  58 #endif
  59 #ifdef BR_BINFMT_FLAT
  60         "-Wl,-elf2flt",
  61 #endif
  62 #ifdef BR_MIPS_TARGET_LITTLE_ENDIAN
  63         "-EL",
  64 #endif
  65 #ifdef BR_MIPS_TARGET_BIG_ENDIAN
  66         "-EB",
  67 #endif
  68 #ifdef BR_ADDITIONAL_CFLAGS
  69         BR_ADDITIONAL_CFLAGS
  70 #endif
  71 };
  72
  73 int main(int argc, char **argv)
  74 {
  75         char **args, **cur;
  76         char *relbasedir, *absbasedir;
  77         char *progpath = argv[0];
  78         char *basename;
  79         char *env_debug;
  80         int ret, i, count = 0, debug;
  81
  82         /* Calculate the relative paths */
  83         basename = strrchr(progpath, '/');
  84         if (basename) {
  85                 *basename = '\0';
  86                 basename++;
  87                 relbasedir = malloc(strlen(progpath) + 7);
  88                 if (relbasedir == NULL) {
  89                         perror(__FILE__ ": malloc");
  90                         return 2;
  91                 }
  92                 sprintf(relbasedir, "%s/../..", argv[0]);
  93                 absbasedir = realpath(relbasedir, NULL);
  94         } else {
  95                 basename = progpath;
  96                 absbasedir = malloc(PATH_MAX + 1);
  97                 ret = readlink("/proc/self/exe", absbasedir, PATH_MAX);
  98                 if (ret < 0) {
  99                         perror(__FILE__ ": readlink");
 100                         return 2;
 101                 }
 102                 absbasedir[ret] = '\0';
 103                 for (i = ret; i > 0; i--) {
 104                         if (absbasedir[i] == '/') {
 105                                 absbasedir[i] = '\0';
 106                                 if (++count == 3)
 107                                         break;
 108                         }
 109                 }
 110         }
 111         if (absbasedir == NULL) {
 112                 perror(__FILE__ ": realpath");
 113                 return 2;
 114         }
 115
 116         /* Fill in the relative paths */
 117 #ifdef BR_CROSS_PATH_REL
 118         ret = snprintf(path, sizeof(path), "%s/" BR_CROSS_PATH_REL "/%s", absbasedir, basename);
 119 #else /* BR_CROSS_PATH_ABS */
 120         ret = snprintf(path, sizeof(path), BR_CROSS_PATH_ABS "/%s", basename);
 121 #endif
 122         if (ret >= sizeof(path)) {
 123                 perror(__FILE__ ": overflow");
 124                 return 3;
 125         }
 126         ret = snprintf(sysroot, sizeof(sysroot), "%s/" BR_SYSROOT, absbasedir);
 127         if (ret >= sizeof(sysroot)) {
 128                 perror(__FILE__ ": overflow");
 129                 return 3;
 130         }
 131
 132         cur = args = malloc(sizeof(predef_args) +
 133                             (sizeof(char *) * (argc + EXCLUSIVE_ARGS)));
 134         if (args == NULL) {
 135                 perror(__FILE__ ": malloc");
 136                 return 2;
 137         }
 138
 139         /* start with predefined args */
 140         memcpy(cur, predef_args, sizeof(predef_args));
 141         cur += sizeof(predef_args) / sizeof(predef_args[0]);
 142
 143 #ifdef BR_FLOAT_ABI
 144         /* add float abi if not overridden in args */
 145         for (i = 1; i < argc; i++) {
 146                 if (!strncmp(argv[i], "-mfloat-abi=", strlen("-mfloat-abi=")) ||
 147                     !strcmp(argv[i], "-msoft-float") ||
 148                     !strcmp(argv[i], "-mhard-float"))
 149                         break;
 150         }
 151
 152         if (i == argc)
 153                 *cur++ = "-mfloat-abi=" BR_FLOAT_ABI;
 154 #endif
 155
 156 #if defined(BR_ARCH) || \
 157     defined(BR_TUNE) || \
 158     defined(BR_CPU)
 159         /* Add our -march/cpu/tune/abi flags, but only if none are
 160          * already specified on the commandline
 161          */
 162         for (i = 1; i < argc; i++) {
 163                 if (!strncmp(argv[i], "-march=", strlen("-march=")) ||
 164                     !strncmp(argv[i], "-mtune=", strlen("-mtune=")) ||
 165                     !strncmp(argv[i], "-mcpu=",  strlen("-mcpu=" )))
 166                         break;
 167         }
 168         if (i == argc) {
 169 #ifdef BR_ARCH
 170                 *cur++ = "-march=" BR_ARCH;
 171 #endif
 172 #ifdef BR_TUNE
 173                 *cur++ = "-mtune=" BR_TUNE;
 174 #endif
 175 #ifdef BR_CPU
 176                 *cur++ = "-mcpu=" BR_CPU;
 177 #endif
 178         }
 179 #endif /* ARCH || TUNE || CPU */
 180
 181         /* append forward args */
 182         memcpy(cur, &argv[1], sizeof(char *) * (argc - 1));
 183         cur += argc - 1;
 184
 185         /* finish with NULL termination */
 186         *cur = NULL;
 187
 188         /* Debug the wrapper to see actual arguments passed to
 189          * the compiler:
 190          * unset, empty, or 0: do not trace
 191          * set to 1          : trace all arguments on a single line
 192          * set to 2          : trace one argument per line
 193          */
 194         if ((env_debug = getenv("BR2_DEBUG_WRAPPER"))) {
 195                 debug = atoi(env_debug);
 196                 if (debug > 0) {
 197                         fprintf(stderr, "Toolchain wrapper executing:");
 198                         for (i = 0; args[i]; i++)
 199                                 fprintf(stderr, "%s'%s'",
 200                                         (debug == 2) ? "\n    " : " ", args[i]);
 201                         fprintf(stderr, "\n");
 202                 }
 203         }
 204
 205         if (execv(path, args))
 206                 perror(path);
 207
 208         free(args);
 209
 210         return 2;
 211 }