Add Utility/ModuleCache class and integrate it with PlatformGDBRemoteServer - in order to allow modules caching from remote targets.

http://reviews.llvm.org/D8037

llvm-svn: 231734

lldb/source/Utility/ModuleCache.cpp

@@ -0,0 +1,132 @@
+//===--------------------- 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 "ModuleCache.h"
+
+#include "lldb/Core/Module.h"
+#include "lldb/Host/FileSystem.h"
+#include "llvm/Support/FileSystem.h"
+
+#include <assert.h>
+
+#include <cstdio>
+#
+using namespace lldb;
+using namespace lldb_private;
+
+namespace {
+
+const char* kModulesSubdir = ".cache";
+
+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.GetPath ().c_str (),
+                                      eFilePermissionsDirectoryDefault);
+}
+
+}  // namespace
+
+Error
+ModuleCache::Put (const FileSpec &root_dir_spec,
+                  const char *hostname,
+                  const UUID &uuid,
+                  const FileSpec &platform_module_spec,
+                  const FileSpec &tmp_file)
+{
+    const auto module_spec_dir = GetModuleDirectory (root_dir_spec, uuid);
+    auto error = MakeDirectory (module_spec_dir);
+    if (error.Fail ())
+        return error;
+
+    const auto module_file_path = JoinPath (module_spec_dir, platform_module_spec.GetFilename ().AsCString ());
+
+    const auto tmp_file_path = tmp_file.GetPath ();
+    const auto err_code = llvm::sys::fs::copy_file (tmp_file_path.c_str (), module_file_path.GetPath ().c_str ());
+    if (err_code)
+    {
+        error.SetErrorStringWithFormat ("failed to copy file %s to %s: %s",
+                                        tmp_file_path.c_str (),
+                                        module_file_path.GetPath ().c_str (),
+                                        err_code.message ().c_str ());
+    }
+
+    // Create sysroot link to a module.
+    const auto sysroot_module_path_spec = GetHostSysRootModulePath (root_dir_spec, hostname, platform_module_spec);
+    return CreateHostSysRootModuleSymLink (sysroot_module_path_spec, module_file_path);
+}
+
+Error
+ModuleCache::Get (const FileSpec &root_dir_spec,
+                  const char *hostname,
+                  const UUID &uuid,
+                  const FileSpec &platform_module_spec,
+                  FileSpec &cached_module_spec)
+{
+    cached_module_spec.Clear ();
+
+    const auto module_spec_dir = GetModuleDirectory (root_dir_spec, uuid);
+    const auto module_file_path = JoinPath (module_spec_dir, platform_module_spec.GetFilename ().AsCString ());
+
+    Error error;
+    if (!module_file_path.Exists ())
+    {
+        error.SetErrorStringWithFormat ("module %s not found", module_file_path.GetPath ().c_str ());
+        return error;
+    }
+    cached_module_spec = module_file_path;
+
+    // We may have already cached module but downloaded from an another host - in this case let's create a symlink to it.
+    const auto sysroot_module_path_spec = GetHostSysRootModulePath (root_dir_spec, hostname, platform_module_spec);
+    if (!sysroot_module_path_spec.Exists ())
+        CreateHostSysRootModuleSymLink (sysroot_module_path_spec, cached_module_spec);
+
+    return error;
+}
+
+FileSpec
+ModuleCache::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
+ModuleCache::GetHostSysRootModulePath (const FileSpec &root_dir_spec, const char *hostname, const FileSpec &platform_module_spec)
+{
+    const auto sysroot_dir = JoinPath (root_dir_spec, hostname);
+    return JoinPath (sysroot_dir, platform_module_spec.GetPath ().c_str ());
+}
+
+Error
+ModuleCache::CreateHostSysRootModuleSymLink (const FileSpec &sysroot_module_path_spec, const FileSpec &module_file_path)
+{
+    const auto error = MakeDirectory (FileSpec (sysroot_module_path_spec.GetDirectory ().AsCString (), false));
+    if (error.Fail ())
+        return error;
+
+    return FileSystem::Symlink (sysroot_module_path_spec.GetPath ().c_str (),
+                                module_file_path.GetPath ().c_str ());
+}