I made the ClangASTImporter owned by the target

rather than individually on behalf of each
ASTContext.  This allows the ASTImporter to know
about all containers of types, which will let it
be smarter about forwarding information about
type origins.  That means that the following
sequence of steps will be possible (after a few
more changes):

- Import a type from a Module's ASTContext into
  an expression parser ASTContext, tracking its
  origin information -- this works now.

- Because the result of the expression uses that
  type, import it from the expression parser
  ASTContext into the Target's scratch AST
  context, forwarding the origin information --
  this needs to be added.

- For a later expression that uses the result,
  import the type from the Target's scratch AST
  context, still forwarding origin information
  -- this also needs to be added.

- Use the intact origin information to complete
  the type as needed -- this works now if the
  origin information is present.

To this end, I made the following changes:

- ASTImporter top-level copy functions now
  require both a source and a destination AST
  context parameter.

- The ASTImporter now knows how to purge
  records related to an ASTContext that is
  going away.

- The Target now owns and creates the ASTImporter
  whenever the main executable changes or (in the
  absence of a main executable) on demand.

llvm-svn: 144802

3 files changed, 47 insertions, 14 deletions

diff --git a/lldb/source/Expression/ClangASTSource.cpp b/lldb/source/Expression/ClangASTSource.cpp
index bfdab164ff9..678504646a6 100644
--- a/lldb/source/Expression/ClangASTSource.cpp
+++ b/lldb/source/Expression/ClangASTSource.cpp
@@ -24,6 +24,7 @@ using namespace lldb_private;
 
 ClangASTSource::~ClangASTSource() 
 {
+    m_ast_importer->PurgeMaps(m_ast_context);
 }
 
 void
@@ -249,7 +250,7 @@ ClangASTSource::FindExternalLexicalDecls (const DeclContext *decl_context,
                     log->Printf("  FELD[%d] Adding lexical decl %s", current_id, ast_dumper.GetCString());
             }
             
-            Decl *copied_decl = m_ast_importer->CopyDecl(original_ctx, decl);
+            Decl *copied_decl = m_ast_importer->CopyDecl(m_ast_context, original_ctx, decl);
             
             decls.push_back(copied_decl);
         }
@@ -551,7 +552,7 @@ ClangASTSource::FindObjCMethodDecls (NameSearchContext &context)
         
         if (found_interface_decl->getName() == interface_decl->getName())
         {
-            Decl *copied_decl = m_ast_importer->CopyDecl(&method_decl->getASTContext(), method_decl);
+            Decl *copied_decl = m_ast_importer->CopyDecl(m_ast_context, &method_decl->getASTContext(), method_decl);
             
             if (!copied_decl)
                 continue;
@@ -610,7 +611,7 @@ ClangASTSource::FindObjCPropertyDecls (NameSearchContext &context)
     if (!property_decl)
         return;
     
-    Decl *copied_decl = m_ast_importer->CopyDecl(orig_ast_ctx, property_decl);
+    Decl *copied_decl = m_ast_importer->CopyDecl(m_ast_context, orig_ast_ctx, property_decl);
     
     if (!copied_decl)
         return;
@@ -734,7 +735,7 @@ ClangASTSource::AddNamespace (NameSearchContext &context, ClangASTImporter::Name
         
     const ClangNamespaceDecl &namespace_decl = namespace_decls->begin()->second;
     
-    Decl *copied_decl = m_ast_importer->CopyDecl(namespace_decl.GetASTContext(), namespace_decl.GetNamespaceDecl());
+    Decl *copied_decl = m_ast_importer->CopyDecl(m_ast_context, namespace_decl.GetASTContext(), namespace_decl.GetNamespaceDecl());
     
     NamespaceDecl *copied_namespace_decl = dyn_cast<NamespaceDecl>(copied_decl);
     
@@ -750,7 +751,7 @@ ClangASTSource::GuardedCopyType (ASTContext *dest_context,
 {    
     SetImportInProgress(true);
     
-    QualType ret_qual_type = m_ast_importer->CopyType (source_context, QualType::getFromOpaquePtr(clang_type));
+    QualType ret_qual_type = m_ast_importer->CopyType (m_ast_context, source_context, QualType::getFromOpaquePtr(clang_type));
     
     void *ret = ret_qual_type.getAsOpaquePtr();
     
diff --git a/lldb/source/Symbol/ClangASTImporter.cpp b/lldb/source/Symbol/ClangASTImporter.cpp
index 92c2325dd40..93ce2adba03 100644
--- a/lldb/source/Symbol/ClangASTImporter.cpp
+++ b/lldb/source/Symbol/ClangASTImporter.cpp
@@ -19,10 +19,11 @@ using namespace lldb_private;
 using namespace clang;
 
 clang::QualType 
-ClangASTImporter::CopyType (clang::ASTContext *src_ast,
+ClangASTImporter::CopyType (clang::ASTContext *dst_ast,
+                            clang::ASTContext *src_ast,
                             clang::QualType type)
 {
-    MinionSP minion_sp (GetMinion(src_ast, false));
+    MinionSP minion_sp (GetMinion(dst_ast, src_ast));
     
     if (minion_sp)
         return minion_sp->Import(type);
@@ -31,15 +32,13 @@ ClangASTImporter::CopyType (clang::ASTContext *src_ast,
 }
 
 clang::Decl *
-ClangASTImporter::CopyDecl (clang::ASTContext *src_ast,
+ClangASTImporter::CopyDecl (clang::ASTContext *dst_ast,
+                            clang::ASTContext *src_ast,
                             clang::Decl *decl)
 {
     MinionSP minion_sp;
     
-    if (isa<clang::NamespaceDecl>(decl)) 
-        minion_sp = GetMinion(src_ast, true);
-    else
-        minion_sp = GetMinion(src_ast, false);
+    minion_sp = GetMinion(dst_ast, src_ast);
     
     if (minion_sp)
     {
@@ -77,7 +76,7 @@ ClangASTImporter::CompleteTagDecl (clang::TagDecl *decl)
     if (!ClangASTContext::GetCompleteDecl(decl_origin.ctx, decl_origin.decl))
         return;
     
-    MinionSP minion_sp (GetMinion(decl_origin.ctx, false));
+    MinionSP minion_sp (GetMinion(&decl->getASTContext(), decl_origin.ctx));
     
     if (minion_sp)
         minion_sp->ImportDefinition(decl_origin.decl);
@@ -98,7 +97,7 @@ ClangASTImporter::CompleteObjCInterfaceDecl (clang::ObjCInterfaceDecl *interface
     if (!ClangASTContext::GetCompleteDecl(decl_origin.ctx, decl_origin.decl))
         return;
     
-    MinionSP minion_sp (GetMinion(decl_origin.ctx, false));
+    MinionSP minion_sp (GetMinion(&interface_decl->getASTContext(), decl_origin.ctx));
     
     if (minion_sp)
         minion_sp->ImportDefinition(decl_origin.decl);
@@ -148,6 +147,18 @@ ClangASTImporter::BuildNamespaceMap(const clang::NamespaceDecl *decl)
     RegisterNamespaceMap (decl, new_map);
 }
 
+void 
+ClangASTImporter::PurgeMaps (clang::ASTContext *dst_ast)
+{
+    for (MinionMap::iterator i = m_minions.begin(); i != m_minions.end(); )
+    {
+        if ((*i).first.dst == dst_ast)
+            m_minions.erase(i++);
+        else
+            ++i;
+    }
+}
+
 ClangASTImporter::NamespaceMapCompleter::~NamespaceMapCompleter ()
 {
     return;
diff --git a/lldb/source/Target/Target.cpp b/lldb/source/Target/Target.cpp
index e06f11580b5..53e8ccfdac6 100644
--- a/lldb/source/Target/Target.cpp
+++ b/lldb/source/Target/Target.cpp
@@ -61,6 +61,8 @@ Target::Target(Debugger &debugger, const ArchSpec &target_arch, const lldb::Plat
     m_search_filter_sp (),
     m_image_search_paths (ImageSearchPathsChanged, this),
     m_scratch_ast_context_ap (NULL),
+    m_scratch_ast_source_ap (NULL),
+    m_ast_importer_ap (NULL),
     m_persistent_variables (),
     m_source_manager(*this),
     m_stop_hooks (),
@@ -173,6 +175,7 @@ Target::Destroy()
     m_image_search_paths.Clear(notify);
     m_scratch_ast_context_ap.reset();
     m_scratch_ast_source_ap.reset();
+    m_ast_importer_ap.reset();
     m_persistent_variables.Clear();
     m_stop_hooks.clear();
     m_stop_hook_next_id = 0;
@@ -797,6 +800,7 @@ Target::SetExecutableModule (ModuleSP& executable_sp, bool get_dependent_files)
     m_images.Clear();
     m_scratch_ast_context_ap.reset();
     m_scratch_ast_source_ap.reset();
+    m_ast_importer_ap.reset();
     
     if (executable_sp.get())
     {
@@ -837,6 +841,7 @@ Target::SetExecutableModule (ModuleSP& executable_sp, bool get_dependent_files)
             }
         }
         
+        m_ast_importer_ap.reset(new ClangASTImporter());
     }
 
     UpdateInstanceName();
@@ -865,6 +870,8 @@ Target::SetArchitecture (const ArchSpec &arch_spec)
         ModuleSP executable_sp = GetExecutableModule ();
         m_images.Clear();
         m_scratch_ast_context_ap.reset();
+        m_scratch_ast_source_ap.reset();
+        m_ast_importer_ap.reset();
         // Need to do something about unsetting breakpoints.
         
         if (executable_sp)
@@ -1342,6 +1349,20 @@ Target::GetScratchClangASTContext()
     return m_scratch_ast_context_ap.get();
 }
 
+ClangASTImporter *
+Target::GetClangASTImporter()
+{
+    ClangASTImporter *ast_importer = m_ast_importer_ap.get();
+    
+    if (!ast_importer)
+    {
+        ast_importer = new ClangASTImporter();
+        m_ast_importer_ap.reset(ast_importer);
+    }
+    
+    return ast_importer;
+}
+
 void
 Target::SettingsInitialize ()
 {