[lldb] Allow synthetic providers in C++ and fix linking problems

- Allow the definition of synthetic formatters in C++ even when LLDB is built without python scripting support.
- Fix linking problems with the CXXSyntheticChildren

Differential Revision: https://reviews.llvm.org/D158010

Author: walter erquinigo

lldb/include/lldb/DataFormatters/TypeSynthetic.h

@@ -228,9 +228,9 @@ class SyntheticChildren {
     uint32_t m_flags = lldb::eTypeOptionCascade;
   };
 
-  SyntheticChildren(const Flags &flags) : m_flags(flags) {}
+  SyntheticChildren(const Flags &flags);
 
-  virtual ~SyntheticChildren() = default;
+  virtual ~SyntheticChildren();
 
   bool Cascades() const { return m_flags.GetCascades(); }
 
@@ -239,8 +239,8 @@ class SyntheticChildren {
   bool SkipsReferences() const { return m_flags.GetSkipReferences(); }
 
   bool NonCacheable() const { return m_flags.GetNonCacheable(); }
-  
-  bool WantsDereference() const { return m_flags.GetFrontEndWantsDereference();} 
+
+  bool WantsDereference() const { return m_flags.GetFrontEndWantsDereference();}
 
   void SetCascades(bool value) { m_flags.SetCascades(value); }
 
@@ -361,9 +361,9 @@ class CXXSyntheticChildren : public SyntheticChildren {
                                                     lldb::ValueObjectSP)>
       CreateFrontEndCallback;
   CXXSyntheticChildren(const SyntheticChildren::Flags &flags,
-                       const char *description, CreateFrontEndCallback callback)
-      : SyntheticChildren(flags), m_create_callback(std::move(callback)),
-        m_description(description ? description : "") {}
+                       const char *description, CreateFrontEndCallback callback);
+
+  virtual ~CXXSyntheticChildren();
 
   bool IsScripted() override { return false; }
 

lldb/source/Commands/CommandObjectType.cpp

@@ -2171,8 +2171,6 @@ class CommandObjectTypeFilterList
                                        "Show a list of current filters.") {}
 };
 
-#if LLDB_ENABLE_PYTHON
-
 // CommandObjectTypeSynthList
 
 class CommandObjectTypeSynthList
@@ -2184,8 +2182,6 @@ class CommandObjectTypeSynthList
             "Show a list of current synthetic providers.") {}
 };
 
-#endif
-
 // CommandObjectTypeFilterDelete
 
 class CommandObjectTypeFilterDelete : public CommandObjectTypeFormatterDelete {
@@ -2197,8 +2193,6 @@ class CommandObjectTypeFilterDelete : public CommandObjectTypeFormatterDelete {
   ~CommandObjectTypeFilterDelete() override = default;
 };
 
-#if LLDB_ENABLE_PYTHON
-
 // CommandObjectTypeSynthDelete
 
 class CommandObjectTypeSynthDelete : public CommandObjectTypeFormatterDelete {
@@ -2210,7 +2204,6 @@ class CommandObjectTypeSynthDelete : public CommandObjectTypeFormatterDelete {
   ~CommandObjectTypeSynthDelete() override = default;
 };
 
-#endif
 
 // CommandObjectTypeFilterClear
 
@@ -2222,7 +2215,6 @@ class CommandObjectTypeFilterClear : public CommandObjectTypeFormatterClear {
                                         "Delete all existing filter.") {}
 };
 
-#if LLDB_ENABLE_PYTHON
 // CommandObjectTypeSynthClear
 
 class CommandObjectTypeSynthClear : public CommandObjectTypeFormatterClear {
@@ -2393,7 +2385,6 @@ bool CommandObjectTypeSynthAdd::AddSynth(ConstString type_name,
   return true;
 }
 
-#endif
 #define LLDB_OPTIONS_type_filter_add
 #include "CommandOptions.inc"
 
@@ -2941,8 +2932,6 @@ class CommandObjectTypeFormat : public CommandObjectMultiword {
   ~CommandObjectTypeFormat() override = default;
 };
 
-#if LLDB_ENABLE_PYTHON
-
 class CommandObjectTypeSynth : public CommandObjectMultiword {
 public:
   CommandObjectTypeSynth(CommandInterpreter &interpreter)
@@ -2970,8 +2959,6 @@ class CommandObjectTypeSynth : public CommandObjectMultiword {
   ~CommandObjectTypeSynth() override = default;
 };
 
-#endif
-
 class CommandObjectTypeFilter : public CommandObjectMultiword {
 public:
   CommandObjectTypeFilter(CommandInterpreter &interpreter)
@@ -3056,10 +3043,8 @@ CommandObjectType::CommandObjectType(CommandInterpreter &interpreter)
                  CommandObjectSP(new CommandObjectTypeFormat(interpreter)));
   LoadSubCommand("summary",
                  CommandObjectSP(new CommandObjectTypeSummary(interpreter)));
-#if LLDB_ENABLE_PYTHON
   LoadSubCommand("synthetic",
                  CommandObjectSP(new CommandObjectTypeSynth(interpreter)));
-#endif
   LoadSubCommand("lookup",
                  CommandObjectSP(new CommandObjectTypeLookup(interpreter)));
 }

lldb/source/Core/ValueObject.cpp

@@ -218,10 +218,8 @@ bool ValueObject::UpdateFormatsIfNeeded() {
     SetValueFormat(DataVisualization::GetFormat(*this, eNoDynamicValues));
     SetSummaryFormat(
         DataVisualization::GetSummaryFormat(*this, GetDynamicValueType()));
-#if LLDB_ENABLE_PYTHON
     SetSyntheticChildren(
         DataVisualization::GetSyntheticChildren(*this, GetDynamicValueType()));
-#endif
   }
 
   return any_change;
@@ -1153,7 +1151,7 @@ bool ValueObject::DumpPrintableRepresentation(
     Stream &s, ValueObjectRepresentationStyle val_obj_display,
     Format custom_format, PrintableRepresentationSpecialCases special,
     bool do_dump_error) {
-    
+
   // If the ValueObject has an error, we might end up dumping the type, which
   // is useful, but if we don't even have a type, then don't examine the object
   // further as that's not meaningful, only the error is.
@@ -2766,15 +2764,15 @@ ValueObjectSP ValueObject::DoCast(const CompilerType &compiler_type) {
 
 ValueObjectSP ValueObject::Cast(const CompilerType &compiler_type) {
   // Only allow casts if the original type is equal or larger than the cast
-  // type.  We don't know how to fetch more data for all the ConstResult types, 
+  // type.  We don't know how to fetch more data for all the ConstResult types,
   // so we can't guarantee this will work:
   Status error;
   CompilerType my_type = GetCompilerType();
 
-  ExecutionContextScope *exe_scope 
+  ExecutionContextScope *exe_scope
       = ExecutionContext(GetExecutionContextRef())
           .GetBestExecutionContextScope();
-  if (compiler_type.GetByteSize(exe_scope) 
+  if (compiler_type.GetByteSize(exe_scope)
       <= GetCompilerType().GetByteSize(exe_scope)) {
         return DoCast(compiler_type);
   }

lldb/source/DataFormatters/TypeSynthetic.cpp

@@ -84,6 +84,27 @@ std::string TypeFilterImpl::GetDescription() {
   return std::string(sstr.GetString());
 }
 
+SyntheticChildren::SyntheticChildren(const Flags &flags) : m_flags(flags) {}
+
+SyntheticChildren::~SyntheticChildren() = default;
+
+CXXSyntheticChildren::CXXSyntheticChildren(
+    const SyntheticChildren::Flags &flags, const char *description,
+    CreateFrontEndCallback callback)
+    : SyntheticChildren(flags), m_create_callback(std::move(callback)),
+      m_description(description ? description : "") {}
+
+CXXSyntheticChildren::~CXXSyntheticChildren() = default;
+
+bool SyntheticChildren::IsScripted() { return false; }
+
+std::string SyntheticChildren::GetDescription() { return ""; }
+
+SyntheticChildrenFrontEnd::AutoPointer
+SyntheticChildren::GetFrontEnd(ValueObject &backend) {
+  return nullptr;
+}
+
 std::string CXXSyntheticChildren::GetDescription() {
   StreamString sstr;
   sstr.Printf("%s%s%s %s", Cascades() ? "" : " (not cascading)",