[lldb] Move UnixSignals creation into Platform plugins

The high level goal of this change is to remove lldbTarget's dependency
on lldbPluginProcessUtility. The reason for this existing dependency is
so that we can create the appropriate UnixSignals object based on an
ArchSpec. Instead of using the ArchSpec, we can instead take advantage
of the Platform associated with the current Target.

This is accomplished by adding a new method to Platform,
CreateUnixSignals, which will create the correct UnixSignals object for
us. We then can use `Platform::GetUnixSignals` and rely on that to give
us the correct signals as needed.

Differential Revision: https://reviews.llvm.org/D146263

Author: bulbazord

lldb/include/lldb/Target/Platform.h

@@ -619,10 +619,12 @@ class Platform : public PluginInterface {
     return 1;
   }
 
-  virtual const lldb::UnixSignalsSP &GetRemoteUnixSignals();
+  virtual lldb::UnixSignalsSP GetRemoteUnixSignals();
 
   lldb::UnixSignalsSP GetUnixSignals();
 
+  virtual lldb::UnixSignalsSP CreateUnixSignals() = 0;
+
   /// Locate a queue name given a thread's qaddr
   ///
   /// On a system using libdispatch ("Grand Central Dispatch") style queues, a

lldb/include/lldb/Target/UnixSignals.h

@@ -22,7 +22,6 @@ namespace lldb_private {
 
 class UnixSignals {
 public:
-  static lldb::UnixSignalsSP Create(const ArchSpec &arch);
   static lldb::UnixSignalsSP CreateForHost();
 
   // Constructors and Destructors

lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/CMakeLists.txt

@@ -19,6 +19,7 @@ add_lldb_library(lldbPluginAppleObjCRuntime PLUGIN
     lldbUtility
     lldbPluginExpressionParserClang
     lldbPluginCPPRuntime
+    lldbPluginProcessUtility
     lldbPluginTypeSystemClang
   CLANG_LIBS
     clangAST

lldb/source/Plugins/Platform/FreeBSD/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_lldb_library(lldbPluginPlatformFreeBSD PLUGIN
+  FreeBSDSignals.cpp
   PlatformFreeBSD.cpp
 
    LINK_LIBS

lldb/source/Plugins/Process/Utility/FreeBSDSignals.cpp renamed to lldb/source/Plugins/Platform/FreeBSD/FreeBSDSignals.cpp

@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "PlatformFreeBSD.h"
+#include "FreeBSDSignals.h"
 #include "lldb/Host/Config.h"
 
 #include <cstdio>
@@ -282,3 +283,7 @@ CompilerType PlatformFreeBSD::GetSiginfoType(const llvm::Triple &triple) {
   ast->CompleteTagDeclarationDefinition(siginfo_type);
   return siginfo_type;
 }
+
+lldb::UnixSignalsSP PlatformFreeBSD::CreateUnixSignals() {
+  return std::make_shared<FreeBSDSignals>();
+}

lldb/source/Plugins/Process/Utility/FreeBSDSignals.h renamed to lldb/source/Plugins/Platform/FreeBSD/FreeBSDSignals.h

@@ -59,6 +59,8 @@ class PlatformFreeBSD : public PlatformPOSIX {
 
   std::vector<ArchSpec> m_supported_architectures;
 
+  lldb::UnixSignalsSP CreateUnixSignals() override;
+
 private:
   std::mutex m_mutex;
   std::shared_ptr<TypeSystemClang> m_type_system;

lldb/source/Plugins/Platform/FreeBSD/PlatformFreeBSD.cpp

@@ -1,4 +1,5 @@
 add_lldb_library(lldbPluginPlatformLinux PLUGIN
+  LinuxSignals.cpp
   PlatformLinux.cpp
 
    LINK_LIBS

lldb/source/Plugins/Platform/FreeBSD/PlatformFreeBSD.h

@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "PlatformLinux.h"
+#include "LinuxSignals.h"
 #include "lldb/Host/Config.h"
 
 #include <cstdio>
@@ -480,3 +481,7 @@ CompilerType PlatformLinux::GetSiginfoType(const llvm::Triple &triple) {
   ast->CompleteTagDeclarationDefinition(siginfo_type);
   return siginfo_type;
 }
+
+lldb::UnixSignalsSP PlatformLinux::CreateUnixSignals() {
+  return std::make_shared<LinuxSignals>();
+}

lldb/source/Plugins/Platform/Linux/CMakeLists.txt

@@ -64,6 +64,8 @@ class PlatformLinux : public PlatformPOSIX {
 
   std::vector<ArchSpec> m_supported_architectures;
 
+  lldb::UnixSignalsSP CreateUnixSignals() override;
+
 private:
   std::mutex m_mutex;
   std::shared_ptr<TypeSystemClang> m_type_system;

lldb/source/Plugins/Process/Utility/LinuxSignals.cpp renamed to lldb/source/Plugins/Platform/Linux/LinuxSignals.cpp

@@ -1,4 +1,5 @@
 add_lldb_library(lldbPluginPlatformNetBSD PLUGIN
+  NetBSDSignals.cpp
   PlatformNetBSD.cpp
 
    LINK_LIBS

lldb/source/Plugins/Process/Utility/LinuxSignals.h renamed to lldb/source/Plugins/Platform/Linux/LinuxSignals.h

@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "PlatformNetBSD.h"
+#include "NetBSDSignals.h"
 #include "lldb/Host/Config.h"
 
 #include <cstdio>
@@ -348,3 +349,7 @@ CompilerType PlatformNetBSD::GetSiginfoType(const llvm::Triple &triple) {
   ast->CompleteTagDeclarationDefinition(siginfo_type);
   return siginfo_type;
 }
+
+lldb::UnixSignalsSP PlatformNetBSD::CreateUnixSignals() {
+  return std::make_shared<NetBSDSignals>();
+}

lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp

@@ -61,6 +61,8 @@ class PlatformNetBSD : public PlatformPOSIX {
 
   std::vector<ArchSpec> m_supported_architectures;
 
+  lldb::UnixSignalsSP CreateUnixSignals() override;
+
 private:
   std::mutex m_mutex;
   std::shared_ptr<TypeSystemClang> m_type_system;

lldb/source/Plugins/Platform/Linux/PlatformLinux.h

@@ -27,6 +27,7 @@
 #include "lldb/Target/ExecutionContext.h"
 #include "lldb/Target/Process.h"
 #include "lldb/Target/Thread.h"
+#include "lldb/Target/UnixSignals.h"
 #include "lldb/Utility/DataBufferHeap.h"
 #include "lldb/Utility/FileSpec.h"
 #include "lldb/Utility/LLDBLog.h"
@@ -294,9 +295,13 @@ std::string PlatformPOSIX::GetPlatformSpecificConnectionInformation() {
     return "";
 }
 
-const lldb::UnixSignalsSP &PlatformPOSIX::GetRemoteUnixSignals() {
-  if (IsRemote() && m_remote_platform_sp)
-    return m_remote_platform_sp->GetRemoteUnixSignals();
+lldb::UnixSignalsSP PlatformPOSIX::GetRemoteUnixSignals() {
+  if (IsRemote() && m_remote_platform_sp) {
+    if (auto unix_signals_sp = m_remote_platform_sp->GetRemoteUnixSignals())
+      return unix_signals_sp;
+  }
+  if (auto unix_signals_sp = CreateUnixSignals())
+    return unix_signals_sp;
   return Platform::GetRemoteUnixSignals();
 }
 
@@ -989,3 +994,7 @@ ConstString PlatformPOSIX::GetFullNameForDylib(ConstString basename) {
   stream.Printf("lib%s.so", basename.GetCString());
   return ConstString(stream.GetString());
 }
+
+lldb::UnixSignalsSP PlatformPOSIX::CreateUnixSignals() {
+  return std::make_shared<UnixSignals>();
+}

lldb/source/Plugins/Platform/NetBSD/CMakeLists.txt

@@ -35,7 +35,7 @@ class PlatformPOSIX : public lldb_private::RemoteAwarePlatform {
   GetFile(const lldb_private::FileSpec &source,
           const lldb_private::FileSpec &destination) override;
 
-  const lldb::UnixSignalsSP &GetRemoteUnixSignals() override;
+  lldb::UnixSignalsSP GetRemoteUnixSignals() override;
 
   lldb::ProcessSP Attach(lldb_private::ProcessAttachInfo &attach_info,
                          lldb_private::Debugger &debugger,
@@ -69,6 +69,8 @@ class PlatformPOSIX : public lldb_private::RemoteAwarePlatform {
 
   lldb_private::ConstString GetFullNameForDylib(lldb_private::ConstString basename) override;
 
+  lldb::UnixSignalsSP CreateUnixSignals() override;
+
 protected:
   std::unique_ptr<lldb_private::OptionGroupPlatformRSync>
       m_option_group_platform_rsync;

lldb/source/Plugins/Process/Utility/NetBSDSignals.cpp renamed to lldb/source/Plugins/Platform/NetBSD/NetBSDSignals.cpp

@@ -69,6 +69,12 @@ class PlatformQemuUser : public Platform {
         arch, addr, length, prot, flags, fd, offset);
   }
 
+  lldb::UnixSignalsSP CreateUnixSignals() override {
+    // PlatformQemuUser shouldn't create its own UnixSignals. It should defer to
+    // other platforms.
+    return lldb::UnixSignalsSP();
+  }
+
 private:
   static lldb::PlatformSP CreateInstance(bool force, const ArchSpec *arch);
   static void DebuggerInitialize(Debugger &debugger);

lldb/source/Plugins/Process/Utility/NetBSDSignals.h renamed to lldb/source/Plugins/Platform/NetBSD/NetBSDSignals.h

@@ -82,6 +82,10 @@ class PlatformWindows : public RemoteAwarePlatform {
 
   std::vector<ArchSpec> m_supported_architectures;
 
+  lldb::UnixSignalsSP CreateUnixSignals() override {
+    return lldb::UnixSignalsSP();
+  }
+
 private:
   std::unique_ptr<lldb_private::UtilityFunction>
   MakeLoadImageUtilityFunction(lldb_private::ExecutionContext &context,

lldb/source/Plugins/Platform/NetBSD/PlatformNetBSD.cpp

@@ -1,11 +1,11 @@
 add_lldb_library(lldbPluginPlatformGDB PLUGIN
+  GDBRemoteSignals.cpp
   PlatformRemoteGDBServer.cpp
 
    LINK_LIBS
     lldbBreakpoint
     lldbCore
     lldbHost
     lldbTarget
-    lldbPluginProcessUtility
     lldbPluginProcessGDBRemote
   )

lldb/source/Plugins/Platform/NetBSD/PlatformNetBSD.h

@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "PlatformRemoteGDBServer.h"
+#include "GDBRemoteSignals.h"
 #include "lldb/Host/Config.h"
 
 #include "lldb/Breakpoint/BreakpointLocation.h"
@@ -31,7 +32,6 @@
 #include "lldb/Utility/UriParser.h"
 #include "llvm/Support/FormatAdapters.h"
 
-#include "Plugins/Process/Utility/GDBRemoteSignals.h"
 #include "Plugins/Process/gdb-remote/ProcessGDBRemote.h"
 #include <optional>
 
@@ -680,17 +680,13 @@ void PlatformRemoteGDBServer::CalculateTrapHandlerSymbolNames() {
   m_trap_handlers.push_back(ConstString("_sigtramp"));
 }
 
-const UnixSignalsSP &PlatformRemoteGDBServer::GetRemoteUnixSignals() {
+UnixSignalsSP PlatformRemoteGDBServer::GetRemoteUnixSignals() {
   if (!IsConnected())
-    return Platform::GetRemoteUnixSignals();
+    return UnixSignalsSP();
 
   if (m_remote_signals_sp)
     return m_remote_signals_sp;
 
-  // If packet not implemented or JSON failed to parse, we'll guess the signal
-  // set based on the remote architecture.
-  m_remote_signals_sp = UnixSignals::Create(GetRemoteSystemArchitecture());
-
   StringExtractorGDBRemote response;
   auto result =
       m_gdb_client_up->SendPacketAndWaitForResponse("jSignalsInfo", response);

lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp

@@ -13,7 +13,6 @@
 #include <optional>
 #include <string>
 
-#include "Plugins/Process/Utility/GDBRemoteSignals.h"
 #include "Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h"
 #include "lldb/Target/Platform.h"
 
@@ -146,14 +145,19 @@ class PlatformRemoteGDBServer : public Platform, private UserIDResolver {
 
   void CalculateTrapHandlerSymbolNames() override;
 
-  const lldb::UnixSignalsSP &GetRemoteUnixSignals() override;
+  lldb::UnixSignalsSP GetRemoteUnixSignals() override;
 
   size_t ConnectToWaitingProcesses(lldb_private::Debugger &debugger,
                                    lldb_private::Status &error) override;
 
   virtual size_t
   GetPendingGdbServerList(std::vector<std::string> &connection_urls);
 
+  lldb::UnixSignalsSP CreateUnixSignals() override {
+    // PlatformRemoteGDBServer should defer to other platforms.
+    return lldb::UnixSignalsSP();
+  }
+
 protected:
   std::unique_ptr<process_gdb_remote::GDBRemoteCommunicationClient>
       m_gdb_client_up;

lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.h

@@ -1,18 +1,14 @@
 add_lldb_library(lldbPluginProcessUtility
   AuxVector.cpp
-  FreeBSDSignals.cpp
-  GDBRemoteSignals.cpp
   HistoryThread.cpp
   HistoryUnwind.cpp
   InferiorCallPOSIX.cpp
   LinuxProcMaps.cpp
-  LinuxSignals.cpp
   MemoryTagManagerAArch64MTE.cpp
   NativeProcessSoftwareSingleStep.cpp
   NativeRegisterContextDBReg_arm64.cpp
   NativeRegisterContextDBReg_x86.cpp
   NativeRegisterContextRegisterInfo.cpp
-  NetBSDSignals.cpp
   RegisterContext_x86.cpp
   RegisterContextDarwin_arm.cpp
   RegisterContextDarwin_arm64.cpp

lldb/source/Plugins/Platform/QemuUser/PlatformQemuUser.h

@@ -18,6 +18,7 @@
 #include "lldb/Target/ABI.h"
 #include "lldb/Target/DynamicLoader.h"
 #include "lldb/Target/MemoryRegionInfo.h"
+#include "lldb/Target/Platform.h"
 #include "lldb/Target/Target.h"
 #include "lldb/Target/UnixSignals.h"
 #include "lldb/Utility/DataBufferHeap.h"
@@ -223,9 +224,10 @@ Status ProcessElfCore::DoLoadCore() {
   ArchSpec target_arch = GetTarget().GetArchitecture();
   ArchSpec core_arch(m_core_module_sp->GetArchitecture());
   target_arch.MergeFrom(core_arch);
-  GetTarget().SetArchitecture(target_arch);
- 
-  SetUnixSignals(UnixSignals::Create(GetArchitecture()));
+  GetTarget().SetArchitecture(target_arch, /* set_platform = */ true);
+
+  if (auto platform_sp = GetTarget().GetPlatform())
+    SetUnixSignals(platform_sp->GetUnixSignals());
 
   // Ensure we found at least one thread that was stopped on a signal.
   bool siginfo_signal_found = false;

lldb/source/Plugins/Platform/Windows/PlatformWindows.h

@@ -74,7 +74,7 @@
 
 #include "GDBRemoteRegisterContext.h"
 #include "GDBRemoteRegisterFallback.h"
-#include "Plugins/Process/Utility/GDBRemoteSignals.h"
+#include "Plugins/Platform/gdb-server/GDBRemoteSignals.h"
 #include "Plugins/Process/Utility/InferiorCallPOSIX.h"
 #include "Plugins/Process/Utility/StopInfoMachException.h"
 #include "ProcessGDBRemote.h"
@@ -967,15 +967,13 @@ void ProcessGDBRemote::DidLaunchOrAttach(ArchSpec &process_arch) {
     MapSupportedStructuredDataPlugins(*supported_packets);
 
   // If connected to LLDB ("native-signals+"), use signal defs for
-  // the remote platform.  If connected to GDB, just use the standard set.
-  if (!m_gdb_comm.UsesNativeSignals()) {
+  // the remote platform (assuming it's available).  If connected to GDB, just
+  // use the standard set.
+  auto platform_sp = GetTarget().GetPlatform();
+  if (!platform_sp || !m_gdb_comm.UsesNativeSignals())
     SetUnixSignals(std::make_shared<GDBRemoteSignals>());
-  } else {
-    PlatformSP platform_sp = GetTarget().GetPlatform();
-    if (platform_sp && platform_sp->IsConnected())
-      SetUnixSignals(platform_sp->GetUnixSignals());
-    else
-      SetUnixSignals(UnixSignals::Create(GetTarget().GetArchitecture()));
+  else {
+    SetUnixSignals(platform_sp->GetUnixSignals());
   }
 }
 

lldb/source/Plugins/Platform/gdb-server/CMakeLists.txt

@@ -206,12 +206,14 @@ Status ProcessMinidump::DoLoadCore() {
                                    arch.GetArchitectureName());
     return error;
   }
-  GetTarget().SetArchitecture(arch, true /*set_platform*/);
+  GetTarget().SetArchitecture(arch, /*set_platform = */ true);
 
   m_thread_list = m_minidump_parser->GetThreads();
   m_active_exception = m_minidump_parser->GetExceptionStream();
 
-  SetUnixSignals(UnixSignals::Create(GetArchitecture()));
+  auto platform_sp = GetTarget().GetPlatform();
+  if (platform_sp)
+    SetUnixSignals(platform_sp->GetUnixSignals());
 
   ReadModuleList();
   if (ModuleSP module = GetTarget().GetExecutableModule())

lldb/source/Plugins/Process/Utility/GDBRemoteSignals.cpp renamed to lldb/source/Plugins/Platform/gdb-server/GDBRemoteSignals.cpp

@@ -85,7 +85,6 @@ add_lldb_library(lldbTarget
     lldbInterpreter
     lldbSymbol
     lldbUtility
-    lldbPluginProcessUtility
 
   LINK_COMPONENTS
     Support

lldb/source/Plugins/Process/Utility/GDBRemoteSignals.h renamed to lldb/source/Plugins/Platform/gdb-server/GDBRemoteSignals.h

@@ -1672,7 +1672,7 @@ FileSpec Platform::GetModuleCacheRoot() {
 
 const char *Platform::GetCacheHostname() { return GetHostname(); }
 
-const UnixSignalsSP &Platform::GetRemoteUnixSignals() {
+UnixSignalsSP Platform::GetRemoteUnixSignals() {
   static const auto s_default_unix_signals_sp = std::make_shared<UnixSignals>();
   return s_default_unix_signals_sp;
 }