[Target] Decouple ObjCLanguageRuntime from LanguageRuntime

Summary:
ObjCLanguageRuntime was being pulled into LanguageRuntime because of
Breakpoint Preconditions. If we move BreakpointPrecondition out of Breakpoint,
we can extend the LanguageRuntime plugin interface so that LanguageRuntimes
can give us a BreakpointPrecondition for exceptions.

Differential Revision: https://reviews.llvm.org/D63181

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@364098 91177308-0d34-0410-b5e6-96231b3b80d8

16 files changed, 135 insertions, 65 deletions

diff --git a/include/lldb/Breakpoint/Breakpoint.h b/include/lldb/Breakpoint/Breakpoint.h
index 7e25d9ff9..f561b6d90 100644
--- a/include/lldb/Breakpoint/Breakpoint.h
+++ b/include/lldb/Breakpoint/Breakpoint.h
@@ -140,19 +140,6 @@ public:
     DISALLOW_COPY_AND_ASSIGN(BreakpointEventData);
   };
 
-  class BreakpointPrecondition {
-  public:
-    virtual ~BreakpointPrecondition() = default;
-
-    virtual bool EvaluatePrecondition(StoppointCallbackContext &context);
-
-    virtual Status ConfigurePrecondition(Args &options);
-
-    virtual void GetDescription(Stream &stream, lldb::DescriptionLevel level);
-  };
-
-  typedef std::shared_ptr<BreakpointPrecondition> BreakpointPreconditionSP;
-
   // Saving & restoring breakpoints:
   static lldb::BreakpointSP CreateFromStructuredData(
       Target &target, StructuredData::ObjectSP &data_object_sp, Status &error);
@@ -558,14 +545,14 @@ public:
   /// The Precondition should not continue the target, it should return true
   /// if the condition says to stop and false otherwise.
   ///
-  void SetPrecondition(BreakpointPreconditionSP precondition_sp) {
+  void SetPrecondition(lldb::BreakpointPreconditionSP precondition_sp) {
     m_precondition_sp = precondition_sp;
   }
 
   bool EvaluatePrecondition(StoppointCallbackContext &context);
 
-  BreakpointPreconditionSP GetPrecondition() { return m_precondition_sp; }
-  
+  lldb::BreakpointPreconditionSP GetPrecondition() { return m_precondition_sp; }
+
   // Produces the OR'ed values for all the names assigned to this breakpoint.
   const BreakpointName::Permissions &GetPermissions() const { 
       return m_permissions; 
@@ -659,9 +646,9 @@ private:
       m_filter_sp; // The filter that constrains the breakpoint's domain.
   lldb::BreakpointResolverSP
       m_resolver_sp; // The resolver that defines this breakpoint.
-  BreakpointPreconditionSP m_precondition_sp; // The precondition is a
-                                              // breakpoint-level hit filter
-                                              // that can be used
+  lldb::BreakpointPreconditionSP m_precondition_sp; // The precondition is a
+                                                    // breakpoint-level hit
+                                                    // filter that can be used
   // to skip certain breakpoint hits.  For instance, exception breakpoints use
   // this to limit the stop to certain exception classes, while leaving the
   // condition & callback free for user specification.
diff --git a/include/lldb/Breakpoint/BreakpointPrecondition.h b/include/lldb/Breakpoint/BreakpointPrecondition.h
new file mode 100644
index 000000000..2a9461b52
--- /dev/null
+++ b/include/lldb/Breakpoint/BreakpointPrecondition.h
@@ -0,0 +1,30 @@
+//===-- BreakpointPrecondition.h --------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_BreakpointPrecondition_h_
+#define liblldb_BreakpointPrecondition_h_
+
+#include "lldb/lldb-enumerations.h"
+
+namespace lldb_private {
+
+class Args;
+class Status;
+class StoppointCallbackContext;
+class Stream;
+
+class BreakpointPrecondition {
+public:
+  virtual ~BreakpointPrecondition() = default;
+  virtual bool EvaluatePrecondition(StoppointCallbackContext &context);
+  virtual Status ConfigurePrecondition(Args &args);
+  virtual void GetDescription(Stream &stream, lldb::DescriptionLevel level);
+};
+} // namespace lldb_private
+
+#endif
diff --git a/include/lldb/Core/PluginManager.h b/include/lldb/Core/PluginManager.h
index b21b5cf14..1bac1e5df 100644
--- a/include/lldb/Core/PluginManager.h
+++ b/include/lldb/Core/PluginManager.h
@@ -134,10 +134,11 @@ public:
   GetLanguageCreateCallbackForPluginName(ConstString name);
 
   // LanguageRuntime
-  static bool
-  RegisterPlugin(ConstString name, const char *description,
-                 LanguageRuntimeCreateInstance create_callback,
-                 LanguageRuntimeGetCommandObject command_callback = nullptr);
+  static bool RegisterPlugin(
+      ConstString name, const char *description,
+      LanguageRuntimeCreateInstance create_callback,
+      LanguageRuntimeGetCommandObject command_callback = nullptr,
+      LanguageRuntimeGetExceptionPrecondition precondition_callback = nullptr);
 
   static bool UnregisterPlugin(LanguageRuntimeCreateInstance create_callback);
 
@@ -147,6 +148,9 @@ public:
   static LanguageRuntimeGetCommandObject
   GetLanguageRuntimeGetCommandObjectAtIndex(uint32_t idx);
 
+  static LanguageRuntimeGetExceptionPrecondition
+  GetLanguageRuntimeGetExceptionPreconditionAtIndex(uint32_t idx);
+
   static LanguageRuntimeCreateInstance
   GetLanguageRuntimeCreateCallbackForPluginName(ConstString name);
 
diff --git a/include/lldb/Target/LanguageRuntime.h b/include/lldb/Target/LanguageRuntime.h
index 91b3b56d5..e3800616c 100644
--- a/include/lldb/Target/LanguageRuntime.h
+++ b/include/lldb/Target/LanguageRuntime.h
@@ -115,9 +115,8 @@ public:
                             bool catch_bp, bool throw_bp,
                             bool is_internal = false);
 
-  static Breakpoint::BreakpointPreconditionSP
-  CreateExceptionPrecondition(lldb::LanguageType language, bool catch_bp,
-                              bool throw_bp);
+  static lldb::BreakpointPreconditionSP
+  GetExceptionPrecondition(lldb::LanguageType language, bool throw_bp);
 
   virtual lldb::ValueObjectSP GetExceptionObjectForThread(
       lldb::ThreadSP thread_sp) {
diff --git a/include/lldb/Target/ObjCLanguageRuntime.h b/include/lldb/Target/ObjCLanguageRuntime.h
index 5b5a6cd2b..4875650d9 100644
--- a/include/lldb/Target/ObjCLanguageRuntime.h
+++ b/include/lldb/Target/ObjCLanguageRuntime.h
@@ -16,6 +16,7 @@
 
 #include "llvm/Support/Casting.h"
 
+#include "lldb/Breakpoint/BreakpointPrecondition.h"
 #include "lldb/Core/PluginInterface.h"
 #include "lldb/Core/ThreadSafeDenseMap.h"
 #include "lldb/Symbol/CompilerType.h"
@@ -154,7 +155,7 @@ public:
     std::unique_ptr<ClangASTContext> m_scratch_ast_ctx_up;
   };
 
-  class ObjCExceptionPrecondition : public Breakpoint::BreakpointPrecondition {
+  class ObjCExceptionPrecondition : public BreakpointPrecondition {
   public:
     ObjCExceptionPrecondition();
 
@@ -171,6 +172,10 @@ public:
     std::unordered_set<std::string> m_class_names;
   };
 
+  static lldb::BreakpointPreconditionSP
+  GetBreakpointExceptionPrecondition(lldb::LanguageType language,
+                                     bool throw_bp);
+
   class TaggedPointerVendor {
   public:
     virtual ~TaggedPointerVendor() = default;
diff --git a/include/lldb/lldb-forward.h b/include/lldb/lldb-forward.h
index ccb5f13e1..0cdaf1cf9 100644
--- a/include/lldb/lldb-forward.h
+++ b/include/lldb/lldb-forward.h
@@ -37,6 +37,7 @@ class BreakpointLocationList;
 class BreakpointName;
 class BreakpointOptionGroup;
 class BreakpointOptions;
+class BreakpointPrecondition;
 class BreakpointResolver;
 class BreakpointSite;
 class BreakpointSiteList;
@@ -298,6 +299,7 @@ typedef std::shared_ptr<lldb_private::BreakpointSite> BreakpointSiteSP;
 typedef std::weak_ptr<lldb_private::BreakpointSite> BreakpointSiteWP;
 typedef std::shared_ptr<lldb_private::BreakpointLocation> BreakpointLocationSP;
 typedef std::weak_ptr<lldb_private::BreakpointLocation> BreakpointLocationWP;
+typedef std::shared_ptr<lldb_private::BreakpointPrecondition> BreakpointPreconditionSP;
 typedef std::shared_ptr<lldb_private::BreakpointResolver> BreakpointResolverSP;
 typedef std::shared_ptr<lldb_private::Broadcaster> BroadcasterSP;
 typedef std::shared_ptr<lldb_private::BroadcasterManager> BroadcasterManagerSP;
diff --git a/include/lldb/lldb-private-interfaces.h b/include/lldb/lldb-private-interfaces.h
index 57b25675b..3a9f78aae 100644
--- a/include/lldb/lldb-private-interfaces.h
+++ b/include/lldb/lldb-private-interfaces.h
@@ -55,6 +55,9 @@ typedef LanguageRuntime *(*LanguageRuntimeCreateInstance)(
     Process *process, lldb::LanguageType language);
 typedef lldb::CommandObjectSP (*LanguageRuntimeGetCommandObject)(
     CommandInterpreter &interpreter);
+typedef lldb::BreakpointPreconditionSP (
+    *LanguageRuntimeGetExceptionPrecondition)(lldb::LanguageType language,
+                                              bool throw_bp);
 typedef lldb::StructuredDataPluginSP (*StructuredDataPluginCreateInstance)(
     Process &process);
 typedef Status (*StructuredDataFilterLaunchInfo)(ProcessLaunchInfo &launch_info,
diff --git a/source/Breakpoint/Breakpoint.cpp b/source/Breakpoint/Breakpoint.cpp
index 0ebba5937..3c3841949 100644
--- a/source/Breakpoint/Breakpoint.cpp
+++ b/source/Breakpoint/Breakpoint.cpp
@@ -11,6 +11,7 @@
 #include "lldb/Breakpoint/Breakpoint.h"
 #include "lldb/Breakpoint/BreakpointLocation.h"
 #include "lldb/Breakpoint/BreakpointLocationCollection.h"
+#include "lldb/Breakpoint/BreakpointPrecondition.h"
 #include "lldb/Breakpoint/BreakpointResolver.h"
 #include "lldb/Breakpoint/BreakpointResolverFileLine.h"
 #include "lldb/Core/Address.h"
@@ -995,21 +996,6 @@ bool Breakpoint::EvaluatePrecondition(StoppointCallbackContext &context) {
   return m_precondition_sp->EvaluatePrecondition(context);
 }
 
-bool Breakpoint::BreakpointPrecondition::EvaluatePrecondition(
-    StoppointCallbackContext &context) {
-  return true;
-}
-
-void Breakpoint::BreakpointPrecondition::GetDescription(
-    Stream &stream, lldb::DescriptionLevel level) {}
-
-Status
-Breakpoint::BreakpointPrecondition::ConfigurePrecondition(Args &options) {
-  Status error;
-  error.SetErrorString("Base breakpoint precondition has no options.");
-  return error;
-}
-
 void Breakpoint::SendBreakpointChangedEvent(
     lldb::BreakpointEventType eventKind) {
   if (!m_being_created && !IsInternal() &&
diff --git a/source/Breakpoint/BreakpointPrecondition.cpp b/source/Breakpoint/BreakpointPrecondition.cpp
new file mode 100644
index 000000000..a387c75c8
--- /dev/null
+++ b/source/Breakpoint/BreakpointPrecondition.cpp
@@ -0,0 +1,26 @@
+//===-- BreakpointPrecondition.cpp ------------------------------*- C++ -*-===//
+//
+// 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 "lldb/Breakpoint/BreakpointPrecondition.h"
+#include "lldb/Utility/Status.h"
+
+using namespace lldb_private;
+
+bool BreakpointPrecondition::EvaluatePrecondition(
+    StoppointCallbackContext &context) {
+  return false;
+}
+
+void BreakpointPrecondition::GetDescription(Stream &stream,
+                                            lldb::DescriptionLevel level) {}
+
+Status BreakpointPrecondition::ConfigurePrecondition(Args &args) {
+  Status error;
+  error.SetErrorString("Base breakpoint precondition has no options.");
+  return error;
+}
diff --git a/source/Breakpoint/CMakeLists.txt b/source/Breakpoint/CMakeLists.txt
index 439946ca9..a7c0baf21 100644
--- a/source/Breakpoint/CMakeLists.txt
+++ b/source/Breakpoint/CMakeLists.txt
@@ -8,6 +8,7 @@ add_lldb_library(lldbBreakpoint
   BreakpointLocationList.cpp
   BreakpointName.cpp
   BreakpointOptions.cpp
+  BreakpointPrecondition.cpp
   BreakpointResolver.cpp
   BreakpointResolverAddress.cpp
   BreakpointResolverFileLine.cpp
diff --git a/source/Core/PluginManager.cpp b/source/Core/PluginManager.cpp
index cf940dd70..24cadcd85 100644
--- a/source/Core/PluginManager.cpp
+++ b/source/Core/PluginManager.cpp
@@ -828,6 +828,7 @@ struct LanguageRuntimeInstance {
   std::string description;
   LanguageRuntimeCreateInstance create_callback;
   LanguageRuntimeGetCommandObject command_callback;
+  LanguageRuntimeGetExceptionPrecondition precondition_callback;
 };
 
 typedef std::vector<LanguageRuntimeInstance> LanguageRuntimeInstances;
@@ -845,7 +846,8 @@ static LanguageRuntimeInstances &GetLanguageRuntimeInstances() {
 bool PluginManager::RegisterPlugin(
     ConstString name, const char *description,
     LanguageRuntimeCreateInstance create_callback,
-    LanguageRuntimeGetCommandObject command_callback) {
+    LanguageRuntimeGetCommandObject command_callback,
+    LanguageRuntimeGetExceptionPrecondition precondition_callback) {
   if (create_callback) {
     LanguageRuntimeInstance instance;
     assert((bool)name);
@@ -854,6 +856,7 @@ bool PluginManager::RegisterPlugin(
       instance.description = description;
     instance.create_callback = create_callback;
     instance.command_callback = command_callback;
+    instance.precondition_callback = precondition_callback;
     std::lock_guard<std::recursive_mutex> guard(GetLanguageRuntimeMutex());
     GetLanguageRuntimeInstances().push_back(instance);
   }
@@ -895,6 +898,15 @@ PluginManager::GetLanguageRuntimeGetCommandObjectAtIndex(uint32_t idx) {
   return nullptr;
 }
 
+LanguageRuntimeGetExceptionPrecondition
+PluginManager::GetLanguageRuntimeGetExceptionPreconditionAtIndex(uint32_t idx) {
+  std::lock_guard<std::recursive_mutex> guard(GetLanguageRuntimeMutex());
+  LanguageRuntimeInstances &instances = GetLanguageRuntimeInstances();
+  if (idx < instances.size())
+    return instances[idx].precondition_callback;
+  return nullptr;
+}
+
 LanguageRuntimeCreateInstance
 PluginManager::GetLanguageRuntimeCreateCallbackForPluginName(
     ConstString name) {
diff --git a/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp b/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
index 49d18c3bb..c8884fd5c 100644
--- a/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
+++ b/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
@@ -85,7 +85,8 @@ AppleObjCRuntimeV1::CreateInstance(Process *process,
 void AppleObjCRuntimeV1::Initialize() {
   PluginManager::RegisterPlugin(
       GetPluginNameStatic(), "Apple Objective-C Language Runtime - Version 1",
-      CreateInstance);
+      CreateInstance,
+      /*command_callback = */ nullptr, GetBreakpointExceptionPrecondition);
 }
 
 void AppleObjCRuntimeV1::Terminate() {
diff --git a/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp b/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
index 64dab7e41..c849a5441 100644
--- a/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
+++ b/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
@@ -806,7 +806,8 @@ void AppleObjCRuntimeV2::Initialize() {
       CreateInstance,
       [](CommandInterpreter &interpreter) -> lldb::CommandObjectSP {
         return CommandObjectSP(new CommandObjectMultiwordObjC(interpreter));
-      });
+      },
+      GetBreakpointExceptionPrecondition);
 }
 
 void AppleObjCRuntimeV2::Terminate() {
diff --git a/source/Target/LanguageRuntime.cpp b/source/Target/LanguageRuntime.cpp
index a75f00854..dd4415810 100644
--- a/source/Target/LanguageRuntime.cpp
+++ b/source/Target/LanguageRuntime.cpp
@@ -11,7 +11,6 @@
 #include "lldb/Core/SearchFilter.h"
 #include "lldb/Interpreter/CommandInterpreter.h"
 #include "lldb/Target/Language.h"
-#include "lldb/Target/ObjCLanguageRuntime.h"
 #include "lldb/Target/Target.h"
 
 using namespace lldb;
@@ -224,19 +223,24 @@ LanguageRuntime::LanguageRuntime(Process *process) : m_process(process) {}
 
 LanguageRuntime::~LanguageRuntime() = default;
 
-Breakpoint::BreakpointPreconditionSP
-LanguageRuntime::CreateExceptionPrecondition(lldb::LanguageType language,
-                                             bool catch_bp, bool throw_bp) {
-  switch (language) {
-  case eLanguageTypeObjC:
-    if (throw_bp)
-      return Breakpoint::BreakpointPreconditionSP(
-          new ObjCLanguageRuntime::ObjCExceptionPrecondition());
-    break;
-  default:
-    break;
+BreakpointPreconditionSP
+LanguageRuntime::GetExceptionPrecondition(LanguageType language,
+                                          bool throw_bp) {
+  LanguageRuntimeCreateInstance create_callback;
+  for (uint32_t idx = 0;
+       (create_callback =
+            PluginManager::GetLanguageRuntimeCreateCallbackAtIndex(idx)) !=
+       nullptr;
+       idx++) {
+    if (auto precondition_callback =
+            PluginManager::GetLanguageRuntimeGetExceptionPreconditionAtIndex(
+                idx)) {
+      if (BreakpointPreconditionSP precond =
+              precondition_callback(language, throw_bp))
+        return precond;
+    }
   }
-  return Breakpoint::BreakpointPreconditionSP();
+  return BreakpointPreconditionSP();
 }
 
 BreakpointSP LanguageRuntime::CreateExceptionBreakpoint(
@@ -252,10 +256,8 @@ BreakpointSP LanguageRuntime::CreateExceptionBreakpoint(
       target.CreateBreakpoint(filter_sp, resolver_sp, is_internal, hardware,
                               resolve_indirect_functions));
   if (exc_breakpt_sp) {
-    Breakpoint::BreakpointPreconditionSP precondition_sp =
-        CreateExceptionPrecondition(language, catch_bp, throw_bp);
-    if (precondition_sp)
-      exc_breakpt_sp->SetPrecondition(precondition_sp);
+    if (auto precond = GetExceptionPrecondition(language, throw_bp))
+      exc_breakpt_sp->SetPrecondition(precond);
 
     if (is_internal)
       exc_breakpt_sp->SetBreakpointKind("exception");
@@ -292,4 +294,3 @@ void LanguageRuntime::InitializeCommands(CommandObject *parent) {
     }
   }
 }
-
diff --git a/source/Target/ObjCLanguageRuntime.cpp b/source/Target/ObjCLanguageRuntime.cpp
index 3084b70e5..ef059a84b 100644
--- a/source/Target/ObjCLanguageRuntime.cpp
+++ b/source/Target/ObjCLanguageRuntime.cpp
@@ -375,6 +375,18 @@ bool ObjCLanguageRuntime::GetTypeBitSize(const CompilerType &compiler_type,
   return found;
 }
 
+lldb::BreakpointPreconditionSP
+ObjCLanguageRuntime::GetBreakpointExceptionPrecondition(LanguageType language,
+                                                        bool throw_bp) {
+  if (language != eLanguageTypeObjC)
+    return lldb::BreakpointPreconditionSP();
+  if (!throw_bp)
+    return lldb::BreakpointPreconditionSP();
+  BreakpointPreconditionSP precondition_sp(
+      new ObjCLanguageRuntime::ObjCExceptionPrecondition());
+  return precondition_sp;
+}
+
 // Exception breakpoint Precondition class for ObjC:
 void ObjCLanguageRuntime::ObjCExceptionPrecondition::AddClassName(
     const char *class_name) {
diff --git a/source/Target/Target.cpp b/source/Target/Target.cpp
index 7f68b28c7..5e83ca038 100644
--- a/source/Target/Target.cpp
+++ b/source/Target/Target.cpp
@@ -11,6 +11,7 @@
 #include "Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.h"
 #include "Plugins/ExpressionParser/Clang/ClangPersistentVariables.h"
 #include "lldb/Breakpoint/BreakpointIDList.h"
+#include "lldb/Breakpoint/BreakpointPrecondition.h"
 #include "lldb/Breakpoint/BreakpointResolver.h"
 #include "lldb/Breakpoint/BreakpointResolverAddress.h"
 #include "lldb/Breakpoint/BreakpointResolverFileLine.h"
@@ -573,8 +574,7 @@ Target::CreateExceptionBreakpoint(enum lldb::LanguageType language,
   BreakpointSP exc_bkpt_sp = LanguageRuntime::CreateExceptionBreakpoint(
       *this, language, catch_bp, throw_bp, internal);
   if (exc_bkpt_sp && additional_args) {
-    Breakpoint::BreakpointPreconditionSP precondition_sp =
-        exc_bkpt_sp->GetPrecondition();
+    BreakpointPreconditionSP precondition_sp = exc_bkpt_sp->GetPrecondition();
     if (precondition_sp && additional_args) {
       if (error)
         *error = precondition_sp->ConfigurePrecondition(*additional_args);