[Target] Remove Target::GetScratchClangASTContext

Target doesn't really need to know about ClangASTContext more than any
other TypeSystem. We can create a method ClangASTContext::GetScratch for
anything who needs a ClangASTContext specifically instead of just a
generic TypeSystem.

lldb/include/lldb/Symbol/ClangASTContext.h

@@ -30,7 +30,10 @@
 #include "lldb/Expression/ExpressionVariable.h"
 #include "lldb/Symbol/CompilerType.h"
 #include "lldb/Symbol/TypeSystem.h"
+#include "lldb/Target/Target.h"
 #include "lldb/Utility/ConstString.h"
+#include "lldb/Utility/Log.h"
+#include "lldb/Utility/Logging.h"
 #include "lldb/lldb-enumerations.h"
 
 class DWARFASTParserClang;
@@ -86,6 +89,18 @@ class ClangASTContext : public TypeSystem {
 
   static ClangASTContext *GetASTContext(clang::ASTContext *ast_ctx);
 
+  static ClangASTContext *GetScratch(Target &target,
+                                     bool create_on_demand = true) {
+    auto type_system_or_err = target.GetScratchTypeSystemForLanguage(
+        lldb::eLanguageTypeC, create_on_demand);
+    if (auto err = type_system_or_err.takeError()) {
+      LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_TARGET),
+                     std::move(err), "Couldn't get scratch ClangASTContext");
+      return nullptr;
+    }
+    return llvm::dyn_cast<ClangASTContext>(&type_system_or_err.get());
+  }
+
   clang::ASTContext *getASTContext();
 
   clang::Builtin::Context *getBuiltinContext();

lldb/include/lldb/Target/Target.h

@@ -1067,8 +1067,6 @@ class Target : public std::enable_shared_from_this<Target>,
                                                  const char *name,
                                                  Status &error);
 
-  ClangASTContext *GetScratchClangASTContext(bool create_on_demand = true);
-
   lldb::ClangASTImporterSP GetClangASTImporter();
 
   // Install any files through the platform that need be to installed prior to

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp

@@ -1073,7 +1073,7 @@ DynamicLoaderDarwin::GetThreadLocalData(const lldb::ModuleSP module_sp,
         StackFrameSP frame_sp = thread_sp->GetStackFrameAtIndex(0);
         if (frame_sp) {
           ClangASTContext *clang_ast_context =
-              target.GetScratchClangASTContext();
+              ClangASTContext::GetScratch(target);
 
           if (!clang_ast_context)
             return LLDB_INVALID_ADDRESS;

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOS.cpp

@@ -223,7 +223,10 @@ bool DynamicLoaderMacOS::NotifyBreakpointHit(void *baton,
     // get the values from the ABI:
 
     ClangASTContext *clang_ast_context =
-        process->GetTarget().GetScratchClangASTContext();
+        ClangASTContext::GetScratch(process->GetTarget());
+    if (!clang_ast_context)
+      return false;
+
     ValueList argument_values;
 
     Value mode_value;    // enum dyld_notify_mode { dyld_notify_adding=0,

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.cpp

@@ -342,7 +342,10 @@ bool DynamicLoaderMacOSXDYLD::NotifyBreakpointHit(
     // get the values from the ABI:
 
     ClangASTContext *clang_ast_context =
-        process->GetTarget().GetScratchClangASTContext();
+        ClangASTContext::GetScratch(process->GetTarget());
+    if (!clang_ast_context)
+      return false;
+
     ValueList argument_values;
     Value input_value;
 

lldb/source/Plugins/ExpressionParser/Clang/ASTResultSynthesizer.cpp

@@ -453,7 +453,7 @@ void ASTResultSynthesizer::CommitPersistentDecls() {
     ConstString name_cs(name.str().c_str());
 
     Decl *D_scratch = m_target.GetClangASTImporter()->DeportDecl(
-        m_target.GetScratchClangASTContext()->getASTContext(), m_ast_context,
+        ClangASTContext::GetScratch(m_target)->getASTContext(), m_ast_context,
         decl);
 
     if (!D_scratch) {

lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp

@@ -120,14 +120,17 @@ void ClangASTSource::InstallASTContext(ClangASTContext &clang_ast_context,
       // Update the scratch AST context's merger to reflect any new sources we
       // might have come across since the last time an expression was parsed.
 
-      auto scratch_ast_context = static_cast<ClangASTContextForExpressions*>(
-          m_target->GetScratchClangASTContext());
+      if (auto *clang_ast_context = ClangASTContext::GetScratch(*m_target)) {
 
-      scratch_ast_context->GetMergerUnchecked().AddSources(sources);
+        auto scratch_ast_context =
+            static_cast<ClangASTContextForExpressions *>(clang_ast_context);
 
-      sources.push_back({*scratch_ast_context->getASTContext(),
-                         *scratch_ast_context->getFileManager(),
-                         scratch_ast_context->GetOriginMap()});
+        scratch_ast_context->GetMergerUnchecked().AddSources(sources);
+
+        sources.push_back({*scratch_ast_context->getASTContext(),
+                           *scratch_ast_context->getFileManager(),
+                           scratch_ast_context->GetOriginMap()});
+      }
     }
 
     m_merger_up =
@@ -145,7 +148,7 @@ ClangASTSource::~ClangASTSource() {
   // demand by passing false to
   // Target::GetScratchClangASTContext(create_on_demand).
   ClangASTContext *scratch_clang_ast_context =
-      m_target->GetScratchClangASTContext(false);
+      ClangASTContext::GetScratch(*m_target, false);
 
   if (!scratch_clang_ast_context)
     return;

lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp

@@ -108,7 +108,7 @@ bool ClangExpressionDeclMap::WillParse(ExecutionContext &exe_ctx,
     m_parser_vars->m_persistent_vars = llvm::cast<ClangPersistentVariables>(
         target->GetPersistentExpressionStateForLanguage(eLanguageTypeC));
 
-    if (!target->GetScratchClangASTContext())
+    if (!ClangASTContext::GetScratch(*target))
       return false;
   }
 
@@ -201,7 +201,7 @@ static clang::QualType ExportAllDeclaredTypes(
 TypeFromUser ClangExpressionDeclMap::DeportType(ClangASTContext &target,
                                                 ClangASTContext &source,
                                                 TypeFromParser parser_type) {
-  assert(&target == m_target->GetScratchClangASTContext());
+  assert(&target == ClangASTContext::GetScratch(*m_target));
   assert((TypeSystem *)&source == parser_type.GetTypeSystem());
   assert(source.getASTContext() == m_ast_context);
 
@@ -215,7 +215,7 @@ TypeFromUser ClangExpressionDeclMap::DeportType(ClangASTContext &target,
         source.getASTContext()->getSourceManager().getFileID(
             source.getASTContext()->getTranslationUnitDecl()->getLocation());
     auto scratch_ast_context = static_cast<ClangASTContextForExpressions *>(
-        m_target->GetScratchClangASTContext());
+        ClangASTContext::GetScratch(*m_target));
     clang::QualType exported_type = ExportAllDeclaredTypes(
         *m_merger_up.get(), scratch_ast_context->GetMergerUnchecked(),
         *source.getASTContext(), *source.getFileManager(),
@@ -248,8 +248,11 @@ bool ClangExpressionDeclMap::AddPersistentVariable(const NamedDecl *decl,
     if (target == nullptr)
       return false;
 
-    TypeFromUser user_type =
-        DeportType(*target->GetScratchClangASTContext(), *ast, parser_type);
+    auto *clang_ast_context = ClangASTContext::GetScratch(*target);
+    if (!clang_ast_context)
+      return false;
+
+    TypeFromUser user_type = DeportType(*clang_ast_context, *ast, parser_type);
 
     uint32_t offset = m_parser_vars->m_materializer->AddResultVariable(
         user_type, is_lvalue, m_keep_result_in_memory, m_result_delegate, err);
@@ -284,7 +287,9 @@ bool ClangExpressionDeclMap::AddPersistentVariable(const NamedDecl *decl,
   if (target == nullptr)
     return false;
 
-  ClangASTContext *context(target->GetScratchClangASTContext());
+  ClangASTContext *context = ClangASTContext::GetScratch(*target);
+  if (!context)
+    return false;
 
   TypeFromUser user_type = DeportType(*context, *ast, parser_type);
 
@@ -777,7 +782,7 @@ void ClangExpressionDeclMap::SearchPersistenDecls(NameSearchContext &context,
     return;
 
   ClangASTContext *scratch_clang_ast_context =
-      target->GetScratchClangASTContext();
+      ClangASTContext::GetScratch(*target);
 
   if (!scratch_clang_ast_context)
     return;
@@ -1714,7 +1719,9 @@ void ClangExpressionDeclMap::AddOneGenericVariable(NameSearchContext &context,
   if (target == nullptr)
     return;
 
-  ClangASTContext *scratch_ast_context = target->GetScratchClangASTContext();
+  ClangASTContext *scratch_ast_context = ClangASTContext::GetScratch(*target);
+  if (!scratch_ast_context)
+    return;
 
   TypeFromUser user_type(scratch_ast_context->GetBasicType(eBasicTypeVoid)
                              .GetPointerType()

lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp

@@ -572,10 +572,13 @@ bool lldb_private::formatters::LibcxxWStringSummaryProvider(
   location_sp->GetPointeeData(extractor, 0, size);
 
   // std::wstring::size() is measured in 'characters', not bytes
-  auto wchar_t_size = valobj.GetTargetSP()
-                          ->GetScratchClangASTContext()
-                          ->GetBasicType(lldb::eBasicTypeWChar)
-                          .GetByteSize(nullptr);
+  ClangASTContext *ast_context =
+      ClangASTContext::GetScratch(*valobj.GetTargetSP());
+  if (!ast_context)
+    return false;
+
+  auto wchar_t_size =
+      ast_context->GetBasicType(lldb::eBasicTypeWChar).GetByteSize(nullptr);
   if (!wchar_t_size)
     return false;
 

lldb/source/Plugins/Language/ObjC/NSArray.cpp

@@ -461,9 +461,8 @@ lldb_private::formatters::NSArrayMSyntheticFrontEndBase::NSArrayMSyntheticFrontE
     : SyntheticChildrenFrontEnd(*valobj_sp), m_exe_ctx_ref(), m_ptr_size(8),
       m_id_type() {
   if (valobj_sp) {
-    auto *clang_ast_context = valobj_sp->GetExecutionContextRef()
-                                  .GetTargetSP()
-                                  ->GetScratchClangASTContext();
+    auto *clang_ast_context = ClangASTContext::GetScratch(
+        *valobj_sp->GetExecutionContextRef().GetTargetSP());
     if (clang_ast_context)
       m_id_type = CompilerType(
           clang_ast_context,
@@ -610,9 +609,8 @@ lldb_private::formatters::GenericNSArrayISyntheticFrontEnd<D32, D64, Inline>::
   if (valobj_sp) {
     CompilerType type = valobj_sp->GetCompilerType();
     if (type) {
-      auto *clang_ast_context = valobj_sp->GetExecutionContextRef()
-                                    .GetTargetSP()
-                                    ->GetScratchClangASTContext();
+      auto *clang_ast_context = ClangASTContext::GetScratch(
+          *valobj_sp->GetExecutionContextRef().GetTargetSP());
       if (clang_ast_context)
         m_id_type = CompilerType(clang_ast_context,
                                  clang_ast_context->getASTContext()
@@ -780,11 +778,15 @@ lldb_private::formatters::NSArray1SyntheticFrontEnd::GetChildAtIndex(
   static const ConstString g_zero("[0]");
 
   if (idx == 0) {
-    CompilerType id_type(
-        m_backend.GetTargetSP()->GetScratchClangASTContext()->GetBasicType(
-            lldb::eBasicTypeObjCID));
-    return m_backend.GetSyntheticChildAtOffset(
-        m_backend.GetProcessSP()->GetAddressByteSize(), id_type, true, g_zero);
+    auto *clang_ast_context =
+        ClangASTContext::GetScratch(*m_backend.GetTargetSP());
+    if (clang_ast_context) {
+      CompilerType id_type(
+          clang_ast_context->GetBasicType(lldb::eBasicTypeObjCID));
+      return m_backend.GetSyntheticChildAtOffset(
+          m_backend.GetProcessSP()->GetAddressByteSize(), id_type, true,
+          g_zero);
+    }
   }
   return lldb::ValueObjectSP();
 }

lldb/source/Plugins/Language/ObjC/NSDictionary.cpp

@@ -65,7 +65,7 @@ NSDictionary_Additionals::GetAdditionalSynthetics() {
 static CompilerType GetLLDBNSPairType(TargetSP target_sp) {
   CompilerType compiler_type;
 
-  ClangASTContext *target_ast_context = target_sp->GetScratchClangASTContext();
+  ClangASTContext *target_ast_context = ClangASTContext::GetScratch(*target_sp);
 
   if (target_ast_context) {
     ConstString g___lldb_autogen_nspair("__lldb_autogen_nspair");

lldb/source/Plugins/Language/ObjC/NSError.cpp

@@ -86,10 +86,10 @@ bool lldb_private::formatters::NSError_SummaryProvider(
 
   ValueObjectSP domain_str_sp = ValueObject::CreateValueObjectFromData(
       "domain_str", isw.GetAsData(process_sp->GetByteOrder()),
-      valobj.GetExecutionContextRef(), process_sp->GetTarget()
-                                           .GetScratchClangASTContext()
-                                           ->GetBasicType(lldb::eBasicTypeVoid)
-                                           .GetPointerType());
+      valobj.GetExecutionContextRef(),
+      ClangASTContext::GetScratch(process_sp->GetTarget())
+          ->GetBasicType(lldb::eBasicTypeVoid)
+          .GetPointerType());
 
   if (!domain_str_sp)
     return false;
@@ -156,8 +156,8 @@ class NSErrorSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
     m_child_sp = CreateValueObjectFromData(
         "_userInfo", isw.GetAsData(process_sp->GetByteOrder()),
         m_backend.GetExecutionContextRef(),
-        process_sp->GetTarget().GetScratchClangASTContext()->GetBasicType(
-            lldb::eBasicTypeObjCID));
+        ClangASTContext::GetScratch(process_sp->GetTarget())
+            ->GetBasicType(lldb::eBasicTypeObjCID));
     return false;
   }
 

lldb/source/Plugins/Language/ObjC/NSException.cpp

@@ -69,10 +69,12 @@ static bool ExtractFields(ValueObject &valobj, ValueObjectSP *name_sp,
   InferiorSizedWord userinfo_isw(userinfo, *process_sp);
   InferiorSizedWord reserved_isw(reserved, *process_sp);
 
-  CompilerType voidstar = process_sp->GetTarget()
-                              .GetScratchClangASTContext()
-                              ->GetBasicType(lldb::eBasicTypeVoid)
-                              .GetPointerType();
+  auto *clang_ast_context = ClangASTContext::GetScratch(process_sp->GetTarget());
+  if (!clang_ast_context)
+    return false;
+
+  CompilerType voidstar =
+      clang_ast_context->GetBasicType(lldb::eBasicTypeVoid).GetPointerType();
 
   if (name_sp)
     *name_sp = ValueObject::CreateValueObjectFromData(

lldb/source/Plugins/Language/ObjC/NSIndexPath.cpp

@@ -53,9 +53,8 @@ class NSIndexPathSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
     if (!type_system)
       return false;
 
-    ClangASTContext *ast = m_backend.GetExecutionContextRef()
-                               .GetTargetSP()
-                               ->GetScratchClangASTContext();
+    ClangASTContext *ast = ClangASTContext::GetScratch(
+        *m_backend.GetExecutionContextRef().GetTargetSP());
     if (!ast)
       return false;
 

lldb/source/Plugins/Language/ObjC/NSString.cpp

@@ -35,7 +35,7 @@ NSString_Additionals::GetAdditionalSummaries() {
 static CompilerType GetNSPathStore2Type(Target &target) {
   static ConstString g_type_name("__lldb_autogen_nspathstore2");
 
-  ClangASTContext *ast_ctx = target.GetScratchClangASTContext();
+  ClangASTContext *ast_ctx = ClangASTContext::GetScratch(target);
 
   if (!ast_ctx)
     return CompilerType();

lldb/source/Plugins/LanguageRuntime/CPlusPlus/ItaniumABI/ItaniumABILanguageRuntime.cpp

@@ -537,7 +537,10 @@ ValueObjectSP ItaniumABILanguageRuntime::GetExceptionObjectForThread(
     return {};
 
   ClangASTContext *clang_ast_context =
-      m_process->GetTarget().GetScratchClangASTContext();
+      ClangASTContext::GetScratch(m_process->GetTarget());
+  if (!clang_ast_context)
+    return {};
+
   CompilerType voidstar =
       clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
 

lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.cpp

@@ -111,7 +111,10 @@ bool AppleObjCRuntime::GetObjectDescription(Stream &strm, Value &value,
     }
   } else {
     // If it is not a pointer, see if we can make it into a pointer.
-    ClangASTContext *ast_context = target->GetScratchClangASTContext();
+    ClangASTContext *ast_context = ClangASTContext::GetScratch(*target);
+    if (!ast_context)
+      return false;
+
     CompilerType opaque_type = ast_context->GetBasicType(eBasicTypeObjCID);
     if (!opaque_type)
       opaque_type = ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
@@ -123,7 +126,9 @@ bool AppleObjCRuntime::GetObjectDescription(Stream &strm, Value &value,
   arg_value_list.PushValue(value);
 
   // This is the return value:
-  ClangASTContext *ast_context = target->GetScratchClangASTContext();
+  ClangASTContext *ast_context = ClangASTContext::GetScratch(*target);
+  if (!ast_context)
+    return false;
 
   CompilerType return_compiler_type = ast_context->GetCStringType(true);
   Value ret;
@@ -494,9 +499,12 @@ ThreadSP AppleObjCRuntime::GetBacktraceThreadFromException(
   reserved_dict = reserved_dict->GetSyntheticValue();
   if (!reserved_dict) return ThreadSP();
 
+  ClangASTContext *clang_ast_context =
+      ClangASTContext::GetScratch(*exception_sp->GetTargetSP());
+  if (!clang_ast_context)
+    return ThreadSP();
   CompilerType objc_id =
-      exception_sp->GetTargetSP()->GetScratchClangASTContext()->GetBasicType(
-          lldb::eBasicTypeObjCID);
+      clang_ast_context->GetBasicType(lldb::eBasicTypeObjCID);
   ValueObjectSP return_addresses;
 
   auto objc_object_from_address = [&exception_sp, &objc_id](uint64_t addr,