Files
clang-p2996/lldb/source/Plugins/Platform/MacOSX/PlatformRemoteMacOSX.cpp
Jonas Devlieghere 8faca2ed6a [lldb] Fix platform selection on Apple Silicon
Currently, when connecting to a remote iOS device from the command line
on Apple Silicon, we end up using the host platform (PlatfromMacOSX)
instead of remote-ios (PlatformRemoteiOS). This happens because
PlatfromMacOSX includes arm64-apple-ios and arm64e-apple-ios as
compatible architectures, presumably to support debugging iOS Apps on
Apple Silicon [1].

This is a problem for debugging remote ios devices, because the host
platform doesn't look for an expanded shared cache on disk and as a
result we end up reading everything from memory, incurring a significant
performance hit.

The crux of this patch is to make PlatfromMacOSX *not* compatible with
arm64(e)-apple-ios. This also means that we now use remote-ios
(PlatformRemoteiOS) as the platform for debugging iOS apps on Apple
Silicon. This has the (unintended) side effect that unlike we do for the
host platform, we no longer check our local shared cache, and incur a
performance hit on debugging these apps.

To avoid that, PlatformRemoteiOS now also check the local cache to
support this use case, which is cheap enough to do unconditionally for
PlatformRemoteiOS.

[1] https://support.apple.com/guide/app-store/iphone-ipad-apps-mac-apple-silicon-fird2c7092da/mac

Differential revision: https://reviews.llvm.org/D117340
2022-01-14 16:03:49 -08:00

199 lines
6.2 KiB
C++

//===-- PlatformRemoteMacOSX.cpp -------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include <memory>
#include <string>
#include <vector>
#include "PlatformRemoteMacOSX.h"
#include "lldb/Breakpoint/BreakpointLocation.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/ModuleList.h"
#include "lldb/Core/ModuleSpec.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Host/Host.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/Target.h"
#include "lldb/Utility/ArchSpec.h"
#include "lldb/Utility/FileSpec.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/StreamString.h"
using namespace lldb;
using namespace lldb_private;
/// Default Constructor
PlatformRemoteMacOSX::PlatformRemoteMacOSX() : PlatformRemoteDarwinDevice() {}
// Static Variables
static uint32_t g_initialize_count = 0;
// Static Functions
void PlatformRemoteMacOSX::Initialize() {
PlatformDarwin::Initialize();
if (g_initialize_count++ == 0) {
PluginManager::RegisterPlugin(PlatformRemoteMacOSX::GetPluginNameStatic(),
PlatformRemoteMacOSX::GetDescriptionStatic(),
PlatformRemoteMacOSX::CreateInstance);
}
}
void PlatformRemoteMacOSX::Terminate() {
if (g_initialize_count > 0) {
if (--g_initialize_count == 0) {
PluginManager::UnregisterPlugin(PlatformRemoteMacOSX::CreateInstance);
}
}
PlatformDarwin::Terminate();
}
PlatformSP PlatformRemoteMacOSX::CreateInstance(bool force,
const ArchSpec *arch) {
Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PLATFORM));
if (log) {
const char *arch_name;
if (arch && arch->GetArchitectureName())
arch_name = arch->GetArchitectureName();
else
arch_name = "<null>";
const char *triple_cstr =
arch ? arch->GetTriple().getTriple().c_str() : "<null>";
LLDB_LOGF(log, "PlatformMacOSX::%s(force=%s, arch={%s,%s})", __FUNCTION__,
force ? "true" : "false", arch_name, triple_cstr);
}
bool create = force;
if (!create && arch && arch->IsValid()) {
const llvm::Triple &triple = arch->GetTriple();
switch (triple.getVendor()) {
case llvm::Triple::Apple:
create = true;
break;
#if defined(__APPLE__)
// Only accept "unknown" for vendor if the host is Apple and it "unknown"
// wasn't specified (it was just returned because it was NOT specified)
case llvm::Triple::UnknownVendor:
create = !arch->TripleVendorWasSpecified();
break;
#endif
default:
break;
}
if (create) {
switch (triple.getOS()) {
case llvm::Triple::Darwin: // Deprecated, but still support Darwin for
// historical reasons
case llvm::Triple::MacOSX:
break;
#if defined(__APPLE__)
// Only accept "vendor" for vendor if the host is Apple and it "unknown"
// wasn't specified (it was just returned because it was NOT specified)
case llvm::Triple::UnknownOS:
create = !arch->TripleOSWasSpecified();
break;
#endif
default:
create = false;
break;
}
}
}
if (create) {
LLDB_LOGF(log, "PlatformRemoteMacOSX::%s() creating platform",
__FUNCTION__);
return std::make_shared<PlatformRemoteMacOSX>();
}
LLDB_LOGF(log, "PlatformRemoteMacOSX::%s() aborting creation of platform",
__FUNCTION__);
return PlatformSP();
}
std::vector<ArchSpec> PlatformRemoteMacOSX::GetSupportedArchitectures() {
// macOS for ARM64 support both native and translated x86_64 processes
std::vector<ArchSpec> result;
ARMGetSupportedArchitectures(result, llvm::Triple::MacOSX);
// We can't use x86GetSupportedArchitectures() because it uses
// the system architecture for some of its return values and also
// has a 32bits variant.
result.push_back(ArchSpec("x86_64-apple-macosx"));
result.push_back(ArchSpec("x86_64-apple-ios-macabi"));
result.push_back(ArchSpec("arm64-apple-ios"));
result.push_back(ArchSpec("arm64e-apple-ios"));
return result;
}
lldb_private::Status PlatformRemoteMacOSX::GetFileWithUUID(
const lldb_private::FileSpec &platform_file,
const lldb_private::UUID *uuid_ptr, lldb_private::FileSpec &local_file) {
if (m_remote_platform_sp) {
std::string local_os_build;
#if !defined(__linux__)
local_os_build = HostInfo::GetOSBuildString().getValueOr("");
#endif
llvm::Optional<std::string> remote_os_build =
m_remote_platform_sp->GetOSBuildString();
if (local_os_build == remote_os_build) {
// same OS version: the local file is good enough
local_file = platform_file;
return Status();
} else {
// try to find the file in the cache
std::string cache_path(GetLocalCacheDirectory());
std::string module_path(platform_file.GetPath());
cache_path.append(module_path);
FileSpec module_cache_spec(cache_path);
if (FileSystem::Instance().Exists(module_cache_spec)) {
local_file = module_cache_spec;
return Status();
}
// bring in the remote module file
FileSpec module_cache_folder =
module_cache_spec.CopyByRemovingLastPathComponent();
// try to make the local directory first
Status err(
llvm::sys::fs::create_directory(module_cache_folder.GetPath()));
if (err.Fail())
return err;
err = GetFile(platform_file, module_cache_spec);
if (err.Fail())
return err;
if (FileSystem::Instance().Exists(module_cache_spec)) {
local_file = module_cache_spec;
return Status();
} else
return Status("unable to obtain valid module file");
}
}
local_file = platform_file;
return Status();
}
llvm::StringRef PlatformRemoteMacOSX::GetDescriptionStatic() {
return "Remote Mac OS X user platform plug-in.";
}
llvm::StringRef PlatformRemoteMacOSX::GetDeviceSupportDirectoryName() {
return "macOS DeviceSupport";
}
llvm::StringRef PlatformRemoteMacOSX::GetPlatformName() {
return "MacOSX.platform";
}