Add 'third_party/nix/' from commit 'be66c7a6b24e3c3c6157fd37b86c7203d14acf10' r/724

git-subtree-dir: third_party/nix
git-subtree-mainline: cf8cd640c1adf74a3706efbcb0ea4625da106fb2
git-subtree-split: be66c7a6b24e3c3c6157fd37b86c7203d14acf10

1 files changed, 200 insertions, 0 deletions

diff --git a/third_party/nix/src/resolve-system-dependencies/resolve-system-dependencies.cc b/third_party/nix/src/resolve-system-dependencies/resolve-system-dependencies.cc
new file mode 100644
index 000000000000..e02cfc03ec97
--- /dev/null
+++ b/third_party/nix/src/resolve-system-dependencies/resolve-system-dependencies.cc
@@ -0,0 +1,200 @@
+#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");
+}
+
+std::set<std::string> runResolver(const Path & filename)
+{
+    AutoCloseFD fd = open(filename.c_str(), O_RDONLY);
+    if (!fd)
+        throw SysError("opening '%s'", filename);
+
+    struct stat st;
+    if (fstat(fd.get(), &st))
+        throw SysError("statting '%s'", filename);
+
+    if (!S_ISREG(st.st_mode)) {
+        printError("file '%s' is not a regular file", filename);
+        return {};
+    }
+
+    if (st.st_size < sizeof(mach_header_64)) {
+        printError("file '%s' is too short for a MACH binary", filename);
+        return {};
+    }
+
+    char* obj = (char*) mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd.get(), 0);
+    if (!obj)
+        throw SysError("mmapping '%s'", filename);
+
+    ptrdiff_t mach64_offset = 0;
+
+    uint32_t magic = ((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, ((fat_header *) obj)->nfat_arch);
+        for (uint32_t i = 0; i < narches; i++) {
+            fat_arch* arch = (fat_arch*) (obj + sizeof(fat_header) + sizeof(fat_arch) * i);
+            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) {
+            printError(format("Could not find any mach64 blobs in file '%1%', continuing...") % filename);
+            return {};
+        }
+    } else if (magic == MH_MAGIC_64 || magic == MH_CIGAM_64) {
+        mach64_offset = 0;
+    } else {
+        printError(format("Object file has unknown magic number '%1%', skipping it...") % magic);
+        return {};
+    }
+
+    mach_header_64 * m_header = (mach_header_64 *) (obj + mach64_offset);
+
+    bool should_swap = magic == MH_CIGAM_64;
+    ptrdiff_t cmd_offset = mach64_offset + sizeof(mach_header_64);
+
+    std::set<string> libs;
+    for (uint32_t i = 0; i < DO_SWAP(should_swap, m_header->ncmds); i++) {
+        load_command * cmd = (load_command *) (obj + cmd_offset);
+        switch(DO_SWAP(should_swap, cmd->cmd)) {
+            case LC_LOAD_UPWARD_DYLIB:
+            case LC_LOAD_DYLIB:
+            case LC_REEXPORT_DYLIB:
+                libs.insert(std::string((char *) cmd + ((dylib_command*) cmd)->dylib.name.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) == -1)
+        throw SysError("getting attributes of path '%1%'", path);
+
+    return S_ISLNK(st.st_mode);
+}
+
+Path resolveSymlink(const Path & path)
+{
+    auto target = readLink(path);
+    return hasPrefix(target, "/")
+        ? target
+        : dirOf(path) + "/" + target;
+}
+
+std::set<string> resolveTree(const Path & path, PathSet & deps)
+{
+    std::set<string> results;
+    if (deps.count(path))
+        return {};
+    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)
+{
+    if (hasPrefix(path, "/dev")) return {};
+
+    Path cacheFile = resolveCacheFile(path);
+    if (pathExists(cacheFile))
+        return readCacheFile(cacheFile);
+
+    std::set<string> deps, paths;
+    paths.insert(path);
+
+    Path nextPath(path);
+    while (isSymlink(nextPath)) {
+        nextPath = resolveSymlink(nextPath);
+        paths.insert(nextPath);
+    }
+
+    for (auto & t : resolveTree(nextPath, deps))
+        paths.insert(t);
+
+    writeFile(cacheFile, concatStringsSep("\n", 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();
+
+        StringSet impurePaths;
+
+        if (std::string(argv[1]) == "--test")
+            impurePaths.insert(argv[2]);
+        else {
+            auto drv = store->derivationFromPath(Path(argv[1]));
+            impurePaths = tokenizeString<StringSet>(get(drv.env, "__impureHostDeps"));
+            impurePaths.insert("/usr/lib/libSystem.dylib");
+        }
+
+        std::set<string> allPaths;
+
+        for (auto & path : impurePaths)
+            for (auto & p : getPath(path))
+                allPaths.insert(p);
+
+        std::cout << "extra-chroot-dirs" << std::endl;
+        for (auto & path : allPaths)
+            std::cout << path << std::endl;
+        std::cout << std::endl;
+    });
+}