Remove dependencies from Utility to Core and Target.

With this patch, the only dependency left is from Utility
to Host.  After this is broken, Utility will finally be
standalone.

Differential Revision: https://reviews.llvm.org/D29909

llvm-svn: 295088

1 files changed, 336 insertions, 0 deletions

diff --git a/lldb/source/Target/ModuleCache.cpp b/lldb/source/Target/ModuleCache.cpp
new file mode 100644
index 00000000000..de02b984f4c
--- /dev/null
+++ b/lldb/source/Target/ModuleCache.cpp
@@ -0,0 +1,336 @@
+//===--------------------- ModuleCache.cpp ----------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Target/ModuleCache.h"
+
+#include "lldb/Core/Log.h"
+#include "lldb/Core/Module.h"
+#include "lldb/Core/ModuleList.h"
+#include "lldb/Core/ModuleSpec.h"
+#include "lldb/Host/File.h"
+#include "lldb/Host/FileSystem.h"
+#include "lldb/Host/LockFile.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FileUtilities.h"
+
+#include <assert.h>
+
+#include <cstdio>
+
+using namespace lldb;
+using namespace lldb_private;
+
+namespace {
+
+const char *kModulesSubdir = ".cache";
+const char *kLockDirName = ".lock";
+const char *kTempFileName = ".temp";
+const char *kTempSymFileName = ".symtemp";
+const char *kSymFileExtension = ".sym";
+const char *kFSIllegalChars = "\\/:*?\"<>|";
+
+std::string GetEscapedHostname(const char *hostname) {
+  if (hostname == nullptr)
+    hostname = "unknown";
+  std::string result(hostname);
+  size_t size = result.size();
+  for (size_t i = 0; i < size; ++i) {
+    if ((result[i] >= 1 && result[i] <= 31) ||
+        strchr(kFSIllegalChars, result[i]) != nullptr)
+      result[i] = '_';
+  }
+  return result;
+}
+
+class ModuleLock {
+private:
+  File m_file;
+  std::unique_ptr<lldb_private::LockFile> m_lock;
+  FileSpec m_file_spec;
+
+public:
+  ModuleLock(const FileSpec &root_dir_spec, const UUID &uuid, Error &error);
+  void Delete();
+};
+
+FileSpec JoinPath(const FileSpec &path1, const char *path2) {
+  FileSpec result_spec(path1);
+  result_spec.AppendPathComponent(path2);
+  return result_spec;
+}
+
+Error MakeDirectory(const FileSpec &dir_path) {
+  if (dir_path.Exists()) {
+    if (!dir_path.IsDirectory())
+      return Error("Invalid existing path");
+
+    return Error();
+  }
+
+  return FileSystem::MakeDirectory(dir_path, eFilePermissionsDirectoryDefault);
+}
+
+FileSpec GetModuleDirectory(const FileSpec &root_dir_spec, const UUID &uuid) {
+  const auto modules_dir_spec = JoinPath(root_dir_spec, kModulesSubdir);
+  return JoinPath(modules_dir_spec, uuid.GetAsString().c_str());
+}
+
+FileSpec GetSymbolFileSpec(const FileSpec &module_file_spec) {
+  return FileSpec(module_file_spec.GetPath() + kSymFileExtension, false);
+}
+
+void DeleteExistingModule(const FileSpec &root_dir_spec,
+                          const FileSpec &sysroot_module_path_spec) {
+  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_MODULES));
+  UUID module_uuid;
+  {
+    auto module_sp =
+        std::make_shared<Module>(ModuleSpec(sysroot_module_path_spec));
+    module_uuid = module_sp->GetUUID();
+  }
+
+  if (!module_uuid.IsValid())
+    return;
+
+  Error error;
+  ModuleLock lock(root_dir_spec, module_uuid, error);
+  if (error.Fail()) {
+    if (log)
+      log->Printf("Failed to lock module %s: %s",
+                  module_uuid.GetAsString().c_str(), error.AsCString());
+  }
+
+  auto link_count = FileSystem::GetHardlinkCount(sysroot_module_path_spec);
+  if (link_count == -1)
+    return;
+
+  if (link_count > 2) // module is referred by other hosts.
+    return;
+
+  const auto module_spec_dir = GetModuleDirectory(root_dir_spec, module_uuid);
+  FileSystem::DeleteDirectory(module_spec_dir, true);
+  lock.Delete();
+}
+
+void DecrementRefExistingModule(const FileSpec &root_dir_spec,
+                                const FileSpec &sysroot_module_path_spec) {
+  // Remove $platform/.cache/$uuid folder if nobody else references it.
+  DeleteExistingModule(root_dir_spec, sysroot_module_path_spec);
+
+  // Remove sysroot link.
+  FileSystem::Unlink(sysroot_module_path_spec);
+
+  FileSpec symfile_spec = GetSymbolFileSpec(sysroot_module_path_spec);
+  if (symfile_spec.Exists()) // delete module's symbol file if exists.
+    FileSystem::Unlink(symfile_spec);
+}
+
+Error CreateHostSysRootModuleLink(const FileSpec &root_dir_spec,
+                                  const char *hostname,
+                                  const FileSpec &platform_module_spec,
+                                  const FileSpec &local_module_spec,
+                                  bool delete_existing) {
+  const auto sysroot_module_path_spec =
+      JoinPath(JoinPath(root_dir_spec, hostname),
+               platform_module_spec.GetPath().c_str());
+  if (sysroot_module_path_spec.Exists()) {
+    if (!delete_existing)
+      return Error();
+
+    DecrementRefExistingModule(root_dir_spec, sysroot_module_path_spec);
+  }
+
+  const auto error = MakeDirectory(
+      FileSpec(sysroot_module_path_spec.GetDirectory().AsCString(), false));
+  if (error.Fail())
+    return error;
+
+  return FileSystem::Hardlink(sysroot_module_path_spec, local_module_spec);
+}
+
+} // namespace
+
+ModuleLock::ModuleLock(const FileSpec &root_dir_spec, const UUID &uuid,
+                       Error &error) {
+  const auto lock_dir_spec = JoinPath(root_dir_spec, kLockDirName);
+  error = MakeDirectory(lock_dir_spec);
+  if (error.Fail())
+    return;
+
+  m_file_spec = JoinPath(lock_dir_spec, uuid.GetAsString().c_str());
+  m_file.Open(m_file_spec.GetCString(), File::eOpenOptionWrite |
+                                            File::eOpenOptionCanCreate |
+                                            File::eOpenOptionCloseOnExec);
+  if (!m_file) {
+    error.SetErrorToErrno();
+    return;
+  }
+
+  m_lock.reset(new lldb_private::LockFile(m_file.GetDescriptor()));
+  error = m_lock->WriteLock(0, 1);
+  if (error.Fail())
+    error.SetErrorStringWithFormat("Failed to lock file: %s",
+                                   error.AsCString());
+}
+
+void ModuleLock::Delete() {
+  if (!m_file)
+    return;
+
+  m_file.Close();
+  FileSystem::Unlink(m_file_spec);
+}
+
+/////////////////////////////////////////////////////////////////////////
+
+Error ModuleCache::Put(const FileSpec &root_dir_spec, const char *hostname,
+                       const ModuleSpec &module_spec, const FileSpec &tmp_file,
+                       const FileSpec &target_file) {
+  const auto module_spec_dir =
+      GetModuleDirectory(root_dir_spec, module_spec.GetUUID());
+  const auto module_file_path =
+      JoinPath(module_spec_dir, target_file.GetFilename().AsCString());
+
+  const auto tmp_file_path = tmp_file.GetPath();
+  const auto err_code =
+      llvm::sys::fs::rename(tmp_file_path, module_file_path.GetPath());
+  if (err_code)
+    return Error("Failed to rename file %s to %s: %s", tmp_file_path.c_str(),
+                 module_file_path.GetPath().c_str(),
+                 err_code.message().c_str());
+
+  const auto error = CreateHostSysRootModuleLink(
+      root_dir_spec, hostname, target_file, module_file_path, true);
+  if (error.Fail())
+    return Error("Failed to create link to %s: %s",
+                 module_file_path.GetPath().c_str(), error.AsCString());
+  return Error();
+}
+
+Error ModuleCache::Get(const FileSpec &root_dir_spec, const char *hostname,
+                       const ModuleSpec &module_spec,
+                       ModuleSP &cached_module_sp, bool *did_create_ptr) {
+  const auto find_it =
+      m_loaded_modules.find(module_spec.GetUUID().GetAsString());
+  if (find_it != m_loaded_modules.end()) {
+    cached_module_sp = (*find_it).second.lock();
+    if (cached_module_sp)
+      return Error();
+    m_loaded_modules.erase(find_it);
+  }
+
+  const auto module_spec_dir =
+      GetModuleDirectory(root_dir_spec, module_spec.GetUUID());
+  const auto module_file_path = JoinPath(
+      module_spec_dir, module_spec.GetFileSpec().GetFilename().AsCString());
+
+  if (!module_file_path.Exists())
+    return Error("Module %s not found", module_file_path.GetPath().c_str());
+  if (module_file_path.GetByteSize() != module_spec.GetObjectSize())
+    return Error("Module %s has invalid file size",
+                 module_file_path.GetPath().c_str());
+
+  // We may have already cached module but downloaded from an another host - in
+  // this case let's create a link to it.
+  auto error = CreateHostSysRootModuleLink(root_dir_spec, hostname,
+                                           module_spec.GetFileSpec(),
+                                           module_file_path, false);
+  if (error.Fail())
+    return Error("Failed to create link to %s: %s",
+                 module_file_path.GetPath().c_str(), error.AsCString());
+
+  auto cached_module_spec(module_spec);
+  cached_module_spec.GetUUID().Clear(); // Clear UUID since it may contain md5
+                                        // content hash instead of real UUID.
+  cached_module_spec.GetFileSpec() = module_file_path;
+  cached_module_spec.GetPlatformFileSpec() = module_spec.GetFileSpec();
+
+  error = ModuleList::GetSharedModule(cached_module_spec, cached_module_sp,
+                                      nullptr, nullptr, did_create_ptr, false);
+  if (error.Fail())
+    return error;
+
+  FileSpec symfile_spec = GetSymbolFileSpec(cached_module_sp->GetFileSpec());
+  if (symfile_spec.Exists())
+    cached_module_sp->SetSymbolFileFileSpec(symfile_spec);
+
+  m_loaded_modules.insert(
+      std::make_pair(module_spec.GetUUID().GetAsString(), cached_module_sp));
+
+  return Error();
+}
+
+Error ModuleCache::GetAndPut(const FileSpec &root_dir_spec,
+                             const char *hostname,
+                             const ModuleSpec &module_spec,
+                             const ModuleDownloader &module_downloader,
+                             const SymfileDownloader &symfile_downloader,
+                             lldb::ModuleSP &cached_module_sp,
+                             bool *did_create_ptr) {
+  const auto module_spec_dir =
+      GetModuleDirectory(root_dir_spec, module_spec.GetUUID());
+  auto error = MakeDirectory(module_spec_dir);
+  if (error.Fail())
+    return error;
+
+  ModuleLock lock(root_dir_spec, module_spec.GetUUID(), error);
+  if (error.Fail())
+    return Error("Failed to lock module %s: %s",
+                 module_spec.GetUUID().GetAsString().c_str(),
+                 error.AsCString());
+
+  const auto escaped_hostname(GetEscapedHostname(hostname));
+  // Check local cache for a module.
+  error = Get(root_dir_spec, escaped_hostname.c_str(), module_spec,
+              cached_module_sp, did_create_ptr);
+  if (error.Success())
+    return error;
+
+  const auto tmp_download_file_spec = JoinPath(module_spec_dir, kTempFileName);
+  error = module_downloader(module_spec, tmp_download_file_spec);
+  llvm::FileRemover tmp_file_remover(tmp_download_file_spec.GetPath());
+  if (error.Fail())
+    return Error("Failed to download module: %s", error.AsCString());
+
+  // Put downloaded file into local module cache.
+  error = Put(root_dir_spec, escaped_hostname.c_str(), module_spec,
+              tmp_download_file_spec, module_spec.GetFileSpec());
+  if (error.Fail())
+    return Error("Failed to put module into cache: %s", error.AsCString());
+
+  tmp_file_remover.releaseFile();
+  error = Get(root_dir_spec, escaped_hostname.c_str(), module_spec,
+              cached_module_sp, did_create_ptr);
+  if (error.Fail())
+    return error;
+
+  // Fetching a symbol file for the module
+  const auto tmp_download_sym_file_spec =
+      JoinPath(module_spec_dir, kTempSymFileName);
+  error = symfile_downloader(cached_module_sp, tmp_download_sym_file_spec);
+  llvm::FileRemover tmp_symfile_remover(tmp_download_sym_file_spec.GetPath());
+  if (error.Fail())
+    // Failed to download a symfile but fetching the module was successful. The
+    // module might
+    // contain the necessary symbols and the debugging is also possible without
+    // a symfile.
+    return Error();
+
+  error = Put(root_dir_spec, escaped_hostname.c_str(), module_spec,
+              tmp_download_sym_file_spec,
+              GetSymbolFileSpec(module_spec.GetFileSpec()));
+  if (error.Fail())
+    return Error("Failed to put symbol file into cache: %s", error.AsCString());
+
+  tmp_symfile_remover.releaseFile();
+
+  FileSpec symfile_spec = GetSymbolFileSpec(cached_module_sp->GetFileSpec());
+  cached_module_sp->SetSymbolFileFileSpec(symfile_spec);
+  return Error();
+}