static StgBool loadFatArchive()

in rts/linker/LoadArchive.c [41:105]

• 58 lines of code
• 10 McCabe index (conditional complexity)

static StgBool loadFatArchive(char tmp[static 20], FILE* f, pathchar* path)
{
    uint32_t nfat_arch, nfat_offset, cputype, cpusubtype;
#if defined(i386_HOST_ARCH)
    const uint32_t mycputype = CPU_TYPE_X86;
    const uint32_t mycpusubtype = CPU_SUBTYPE_X86_ALL;
#elif defined(x86_64_HOST_ARCH)
    const uint32_t mycputype = CPU_TYPE_X86_64;
    const uint32_t mycpusubtype = CPU_SUBTYPE_X86_64_ALL;
#elif defined(aarch64_HOST_ARCH)
    const uint32_t mycputype = CPU_TYPE_ARM64;
    const uint32_t mycpusubtype = CPU_SUBTYPE_ARM64_ALL;
#elif defined(powerpc_HOST_ARCH) || defined(powerpc64_HOST_ARCH)
#error No Darwin support on PowerPC
#else
#error Unknown Darwin architecture
#endif

    nfat_arch = read4Bytes(tmp + 4);
    DEBUG_LOG("found a fat archive containing %d architectures\n", nfat_arch);
    nfat_offset = 0;
    for (uint32_t i = 0; i < nfat_arch; i++) {
        /* search for the right arch */
        int n = fread(tmp, 1, 12, f);
        if (n != 12) {
            errorBelch("Failed reading arch from `%" PATH_FMT "'", path);
            return false;
        }
        cputype = read4Bytes(tmp);
        cpusubtype = read4Bytes(tmp + 4);
        if (cputype == mycputype && cpusubtype == mycpusubtype) {
            DEBUG_LOG("found my archive in a fat archive\n");
            nfat_offset = read4Bytes(tmp + 8);
            break;
        }
    }
    if (nfat_offset == 0) {
        errorBelch("Fat archive contains %d architectures, "
                   "but none of them are compatible with the host",
                   (int)nfat_arch);
        return false;
    } else {
        /* Seek to the correct architecture */
        int n = fseek(f, nfat_offset, SEEK_SET);
        if (n != 0) {
            errorBelch("Failed to seek to arch in `%" PATH_FMT "'", path);
            return false;
        }

        /* Read the header */
        n = fread(tmp, 1, 8, f);
        if (n != 8) {
            errorBelch("Failed reading header from `%" PATH_FMT "'", path);
            return false;
        }

        /* Check the magic number */
        if (strncmp(tmp, "!<arch>\n", 8) != 0) {
            errorBelch("couldn't find archive in `%" PATH_FMT "'"
                       "at offset %d", path, nfat_offset);
            return false;
        }
    }
    return true;
}