lix/src/resolve-system-dependencies/resolve-system-dependencies.cc
2016-08-16 12:52:49 -07:00

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#include "derivations.hh"
#include "globals.hh"
#include "shared.hh"
#include "store-api.hh"
#include <sys/utsname.h>
#include <algorithm>
#include <iostream>
#include <fstream>
#include <sys/mman.h>
#include <fcntl.h>
#include <mach-o/loader.h>
#include <mach-o/swap.h>
#define DO_SWAP(x, y) ((x) ? OSSwapInt32(y) : (y))
using namespace nix;
static auto cacheDir = Path{};
Path resolveCacheFile(Path lib) {
std::replace(lib.begin(), lib.end(), '/', '%');
return cacheDir + "/" + lib;
}
std::set<string> readCacheFile(const Path & file) {
return tokenizeString<set<string>>(readFile(file), "\n");
}
void writeCacheFile(const Path & file, std::set<string> & deps) {
std::ofstream fp;
fp.open(file);
for (auto & d : deps) {
fp << d << "\n";
}
fp.close();
}
std::string findDylibName(bool should_swap, ptrdiff_t dylib_command_start) {
struct dylib_command *dylc = (struct dylib_command*)dylib_command_start;
return std::string((char*)(dylib_command_start + DO_SWAP(should_swap, dylc->dylib.name.offset)));
}
std::set<std::string> runResolver(const Path & filename) {
int fd = open(filename.c_str(), O_RDONLY);
struct stat s;
fstat(fd, &s);
void *obj = mmap(NULL, s.st_size, PROT_READ, MAP_SHARED, fd, 0);
ptrdiff_t mach64_offset = 0;
uint32_t magic = ((struct mach_header_64*)obj)->magic;
if(magic == FAT_CIGAM || magic == FAT_MAGIC) {
bool should_swap = magic == FAT_CIGAM;
uint32_t narches = DO_SWAP(should_swap, ((struct fat_header*)obj)->nfat_arch);
for(uint32_t iter = 0; iter < narches; iter++) {
ptrdiff_t header_offset = (ptrdiff_t)obj + sizeof(struct fat_header);
struct fat_arch* arch = (struct fat_arch*)header_offset;
if(DO_SWAP(should_swap, arch->cputype) == CPU_TYPE_X86_64) {
mach64_offset = (ptrdiff_t)DO_SWAP(should_swap, arch->offset);
break;
}
}
if (mach64_offset == 0) {
printMsg(lvlError, format("Could not find any mach64 blobs in file %1%, continuing...") % filename);
return std::set<string>();
}
} else if (magic == MH_MAGIC_64 || magic == MH_CIGAM_64) {
mach64_offset = 0;
} else {
printMsg(lvlError, format("Object file has unknown magic number %1%, skipping it...") % magic);
return std::set<string>();
}
struct mach_header_64 *m_header = (struct mach_header_64 *)((ptrdiff_t)obj + mach64_offset);
bool should_swap = magic == MH_CIGAM_64;
ptrdiff_t cmd_offset = (ptrdiff_t)m_header + sizeof(struct mach_header_64);
std::set<string> libs;
for(uint32_t i = 0; i < DO_SWAP(should_swap, m_header->ncmds); i++) {
struct load_command *cmd = (struct load_command*)cmd_offset;
switch(DO_SWAP(should_swap, cmd->cmd)) {
case LC_LOAD_UPWARD_DYLIB:
case LC_LOAD_DYLIB:
case LC_REEXPORT_DYLIB:
libs.insert(findDylibName(should_swap, cmd_offset));
break;
}
cmd_offset += DO_SWAP(should_swap, cmd->cmdsize);
}
return libs;
}
bool isSymlink(const Path & path) {
struct stat st;
if(lstat(path.c_str(), &st))
throw SysError(format("getting attributes of path %1%") % path);
return S_ISLNK(st.st_mode);
}
Path resolveSymlink(const Path & path) {
char buf[PATH_MAX];
ssize_t len = readlink(path.c_str(), buf, sizeof(buf) - 1);
if(len != -1) {
buf[len] = 0;
return Path(buf);
} else {
throw SysError(format("readlink('%1%')") % path);
}
}
std::set<string> resolveTree(const Path & path, PathSet & deps) {
std::set<string> results;
if(deps.find(path) != deps.end()) {
return std::set<string>();
}
deps.insert(path);
for (auto & lib : runResolver(path)) {
results.insert(lib);
for (auto & p : resolveTree(lib, deps)) {
results.insert(p);
}
}
return results;
}
std::set<string> getPath(const Path & path) {
Path cacheFile = resolveCacheFile(path);
if(pathExists(cacheFile)) {
return readCacheFile(cacheFile);
}
std::set<string> deps;
std::set<string> paths;
paths.insert(path);
Path next_path = Path(path);
while(isSymlink(next_path)) {
next_path = resolveSymlink(next_path);
paths.insert(next_path);
}
for(auto & t : resolveTree(next_path, deps)) {
paths.insert(t);
}
writeCacheFile(cacheFile, paths);
return paths;
}
int main(int argc, char ** argv) {
return handleExceptions(argv[0], [&]() {
initNix();
struct utsname _uname;
uname(&_uname);
auto cacheParentDir = (format("%1%/dependency-maps") % settings.nixStateDir).str();
cacheDir = (format("%1%/%2%-%3%-%4%")
% cacheParentDir
% _uname.machine
% _uname.sysname
% _uname.release).str();
mkdir(cacheParentDir.c_str(), 0755);
mkdir(cacheDir.c_str(), 0755);
auto store = openStore();
auto drv = store->derivationFromPath(Path(argv[1]));
Strings impurePaths = tokenizeString<Strings>(get(drv.env, "__impureHostDeps"));
std::set<string> all_paths;
for (auto & path : impurePaths) {
for(auto & p : getPath(path)) {
all_paths.insert(p);
}
}
std::cout << "extra-chroot-dirs" << std::endl;
for(auto & path : all_paths) {
std::cout << path << std::endl;
}
std::cout << std::endl;
});
}