std::string Environment::system_prefix() {
if(!system_prefix_.empty()) return system_prefix_;
// 1. Check if our configure prefix is overridden by the environment.
const char* path = getenv("RBX_PREFIX_PATH");
if(path && verify_paths(path)) {
system_prefix_ = path;
return path;
}
// 2. Check if our configure prefix is valid.
path = RBX_PREFIX_PATH;
if(verify_paths(path)) {
system_prefix_ = path;
return path;
}
// 3. Check if we can derive paths from the executable name.
// TODO: For Windows, substitute '/' for '\\'
std::string name = executable_name();
size_t exe = name.rfind('/');
if(exe != std::string::npos) {
std::string prefix = name.substr(0, exe - strlen(RBX_BIN_PATH));
if(verify_paths(prefix)) {
system_prefix_ = prefix;
return prefix;
}
}
throw MissingRuntime("FATAL ERROR: unable to find Rubinius runtime directories.");
}
TEST(dlfcn, dladdr) {
dlerror(); // Clear any pending errors.
void* self = dlopen(NULL, RTLD_NOW);
ASSERT_TRUE(self != NULL);
ASSERT_TRUE(dlerror() == NULL);
void* sym = dlsym(self, "DlSymTestFunction");
ASSERT_TRUE(sym != NULL);
// Deliberately ask dladdr for an address inside a symbol, rather than the symbol base address.
void* addr = reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(sym) + 2);
Dl_info info;
int rc = dladdr(addr, &info);
ASSERT_NE(rc, 0); // Zero on error, non-zero on success.
// Get the name of this executable.
char executable_path[PATH_MAX];
rc = readlink("/proc/self/exe", executable_path, sizeof(executable_path));
ASSERT_NE(rc, -1);
executable_path[rc] = '\0';
std::string executable_name(basename(executable_path));
// The filename should be that of this executable.
// Note that we don't know whether or not we have the full path, so we want an "ends_with" test.
std::string dli_fname(info.dli_fname);
dli_fname = basename(&dli_fname[0]);
ASSERT_EQ(dli_fname, executable_name);
// The symbol name should be the symbol we looked up.
ASSERT_STREQ(info.dli_sname, "DlSymTestFunction");
// The address should be the exact address of the symbol.
ASSERT_EQ(info.dli_saddr, sym);
// Look in /proc/pid/maps to find out what address we were loaded at.
// TODO: factor /proc/pid/maps parsing out into a class and reuse all over bionic.
void* base_address = NULL;
char path[PATH_MAX];
snprintf(path, sizeof(path), "/proc/%d/maps", getpid());
char line[BUFSIZ];
FILE* fp = fopen(path, "r");
ASSERT_TRUE(fp != NULL);
while (fgets(line, sizeof(line), fp) != NULL) {
uintptr_t start = strtoul(line, 0, 16);
line[strlen(line) - 1] = '\0'; // Chomp the '\n'.
char* path = strchr(line, '/');
if (path != NULL && strcmp(executable_path, path) == 0) {
base_address = reinterpret_cast<void*>(start);
break;
}
}
fclose(fp);
// The base address should be the address we were loaded at.
ASSERT_EQ(info.dli_fbase, base_address);
ASSERT_EQ(0, dlclose(self));
}
bstring
resolve_path(STATE, bstring path)
{
char *absolute_path = malloc(PATH_MAX);
bstring h = executable_name(state->binary);
struct bstrList *x = bsplit(h, '/');
bdestroy(h);
bstring slash = bfromcstr("/");
x->qty--;
h = bjoin(x, slash);
x->qty++;
bstrListDestroy(x);
bconcat(h, slash);
bconcat(h, path);
bdestroy(slash);
realpath(bdata(h), absolute_path);
bstring bpath = bfromcstr(absolute_path);
bdestroy(h);
free(absolute_path);
return bpath;
}
std::string Environment::system_prefix() {
if(!system_prefix_.empty()) return system_prefix_;
std::string failure_reason;
// 1. Check if our configure prefix is overridden by the environment.
const char* path = getenv("RBX_PREFIX_PATH");
if(path && verify_paths(path, failure_reason)) {
system_prefix_ = path;
return path;
}
// 2. Check if our configure prefix is valid.
path = RBX_PREFIX_PATH;
if(verify_paths(path, failure_reason)) {
system_prefix_ = path;
return path;
}
// 3. Check if we can derive paths from the executable name.
// TODO: For Windows, substitute '/' for '\\'
std::string name = executable_name();
size_t exe = name.rfind('/');
if(exe != std::string::npos) {
std::string prefix = name.substr(0, exe - strlen(RBX_BIN_PATH));
if(verify_paths(prefix, failure_reason)) {
system_prefix_ = prefix;
return prefix;
}
}
std::string error("Unable to find Rubinius runtime directories: ");
error.append(failure_reason);
missing_core(error.c_str());
}
