switch to mmap strategy

This commit is contained in:
Jude Taylor 2016-08-16 12:45:55 -07:00
parent 7b006122ae
commit 90516c5a7b

View file

@ -6,9 +6,13 @@
#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{};
@ -31,76 +35,59 @@ void writeCacheFile(const Path & file, std::set<string> & deps) {
fp.close();
}
std::string findDylibName(FILE *obj_file, struct load_command cmd) {
fpos_t pos;
fgetpos(obj_file, &pos);
struct dylib_command dylc;
dylc.cmd = cmd.cmd;
dylc.cmdsize = cmd.cmdsize;
fread(&dylc.dylib, sizeof(struct dylib), 1, obj_file);
std::string findDylibName(bool should_swap, ptrdiff_t dylib_command_start) {
struct dylib_command *dylc = (struct dylib_command*)dylib_command_start;
char *dylib_name = (char*)calloc(cmd.cmdsize, sizeof(char));
fseek(obj_file,
// offset is calculated from the beginning of the load command, which is two
// uint32_t's backwards
dylc.dylib.name.offset - (sizeof(uint32_t) * 2) + pos,
SEEK_SET);
fread(dylib_name, sizeof(char), cmd.cmdsize, obj_file);
fseek(obj_file, pos, SEEK_SET);
return std::string(dylib_name);
}
bool seekMach64Blob(FILE *obj_file, enum NXByteOrder end) {
struct fat_header head;
fread(&head, sizeof(struct fat_header), 1, obj_file);
swap_fat_header(&head, end);
for(uint32_t narches = 0; narches < head.nfat_arch; narches++) {
struct fat_arch arch;
fread(&arch, sizeof(struct fat_arch), 1, obj_file);
swap_fat_arch(&arch, 1, end);
if(arch.cputype == CPU_TYPE_X86_64) {
fseek(obj_file, arch.offset, SEEK_SET);
return true;
}
}
return false;
return std::string((char*)(dylib_command_start + DO_SWAP(should_swap, dylc->dylib.name.offset)));
}
std::set<std::string> runResolver(const Path & filename) {
FILE *obj_file = fopen(filename.c_str(), "rb");
uint32_t magic;
fread(&magic, sizeof(uint32_t), 1, obj_file);
fseek(obj_file, 0, SEEK_SET);
enum NXByteOrder endianness;
if(magic == 0xBEBAFECA) {
endianness = NX_BigEndian;
if(!seekMach64Blob(obj_file, endianness)) {
std::cerr << "Could not find any mach64 blobs in file " << filename << ", continuing..." << std::endl;
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;
}
struct mach_header_64 header;
fread(&header, sizeof(struct mach_header_64), 1, obj_file);
if(!(header.magic == MH_MAGIC_64 || header.magic == MH_CIGAM_64)) {
std::cerr << "Not a mach-o object file: " << filename << std::endl;
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 < header.ncmds; i++) {
struct load_command cmd;
fread(&cmd.cmd, sizeof(cmd.cmd), 1, obj_file);
fread(&cmd.cmdsize, sizeof(cmd.cmdsize), 1, obj_file);
switch(cmd.cmd) {
case LC_LOAD_DYLIB:
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(obj_file, cmd));
libs.insert(findDylibName(should_swap, cmd_offset));
break;
}
fseek(obj_file, cmd.cmdsize - (sizeof(uint32_t) * 2), SEEK_CUR);
cmd_offset += DO_SWAP(should_swap, cmd->cmdsize);
}
fclose(obj_file);
libs.erase(filename);
return libs;
}
@ -165,40 +152,40 @@ std::set<string> getPath(const Path & path) {
int main(int argc, char ** argv) {
return handleExceptions(argv[0], [&]() {
initNix();
initNix();
struct utsname _uname;
struct utsname _uname;
uname(&_uname);
uname(&_uname);
auto cacheParentDir = (format("%1%/dependency-maps") % settings.nixStateDir).str();
auto cacheParentDir = (format("%1%/dependency-maps") % settings.nixStateDir).str();
cacheDir = (format("%1%/%2%-%3%-%4%")
% cacheParentDir
% _uname.machine
% _uname.sysname
% _uname.release).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);
mkdir(cacheParentDir.c_str(), 0755);
mkdir(cacheDir.c_str(), 0755);
auto store = openStore();
auto store = openStore();
auto drv = store->derivationFromPath(Path(argv[1]));
Strings impurePaths = tokenizeString<Strings>(get(drv.env, "__impureHostDeps"));
auto drv = store->derivationFromPath(Path(argv[1]));
Strings impurePaths = tokenizeString<Strings>(get(drv.env, "__impureHostDeps"));
std::set<string> all_paths;
std::set<string> all_paths;
for (auto & path : impurePaths) {
for(auto & p : getPath(path)) {
all_paths.insert(p);
}
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;
std::cout << "extra-chroot-dirs" << std::endl;
for(auto & path : all_paths) {
std::cout << path << std::endl;
}
std::cout << std::endl;
});
}