Now that we get types from modules, we occasionally

encounter clang::ExternalASTSources that are not instances
of ClangExternalASTSourceCommon.  We used to blithely
assume that all are, and so we could use static_cast<>.
That's no longer the case, so we have to have these AST
sources register themselves.

llvm-svn: 223560

lldb/include/lldb/Symbol/ClangExternalASTSourceCommon.h

@@ -169,10 +169,13 @@ public:
     ClangExternalASTSourceCommon();
     ~ClangExternalASTSourceCommon();
 
-    virtual ClangASTMetadata *GetMetadata(const void *object);
-    virtual void SetMetadata(const void *object, ClangASTMetadata &metadata);
-    virtual bool HasMetadata(const void *object);
-private:
+    ClangASTMetadata *GetMetadata(const void *object);
+    void SetMetadata(const void *object, ClangASTMetadata &metadata);
+    bool HasMetadata(const void *object);
+    
+    static ClangExternalASTSourceCommon *
+    Lookup(clang::ExternalASTSource *source);
+private:    
     typedef llvm::DenseMap<const void *, ClangASTMetadata> MetadataMap;
     
     MetadataMap m_metadata;

lldb/source/Symbol/ClangASTContext.cpp

@@ -2106,7 +2106,7 @@ ClangASTContext::SetMetadata (clang::ASTContext *ast,
                               ClangASTMetadata &metadata)
 {
     ClangExternalASTSourceCommon *external_source =
-        static_cast<ClangExternalASTSourceCommon*>(ast->getExternalSource());
+        ClangExternalASTSourceCommon::Lookup(ast->getExternalSource());
     
     if (external_source)
         external_source->SetMetadata(object, metadata);
@@ -2117,7 +2117,7 @@ ClangASTContext::GetMetadata (clang::ASTContext *ast,
                               const void *object)
 {
     ClangExternalASTSourceCommon *external_source =
-        static_cast<ClangExternalASTSourceCommon*>(ast->getExternalSource());
+        ClangExternalASTSourceCommon::Lookup(ast->getExternalSource());
     
     if (external_source && external_source->HasMetadata(object))
         return external_source->GetMetadata(object);

lldb/source/Symbol/ClangExternalASTSourceCommon.cpp

@@ -9,30 +9,52 @@
 
 #include "lldb/Symbol/ClangExternalASTSourceCommon.h"
 #include "lldb/Core/Stream.h"
+#include "lldb/Host/Mutex.h"
 
 using namespace lldb_private;
 
-#define ClangExternalASTSourceCommon_MAGIC  (0x00112233aabbccddull)
-
 uint64_t g_TotalSizeOfMetadata = 0;
 
+typedef llvm::DenseMap<clang::ExternalASTSource *, ClangExternalASTSourceCommon *> ASTSourceMap;
+
+static ASTSourceMap &GetSourceMap()
+{
+    static ASTSourceMap s_source_map;
+    return s_source_map;
+}
+
+ClangExternalASTSourceCommon *
+ClangExternalASTSourceCommon::Lookup(clang::ExternalASTSource *source)
+{
+    ASTSourceMap &source_map = GetSourceMap();
+    
+    ASTSourceMap::iterator iter = source_map.find(source);
+    
+    if (iter == source_map.end())
+    {
+        return iter->second;
+    }
+    else
+    {
+        return nullptr;
+    }
+}
+
 ClangExternalASTSourceCommon::ClangExternalASTSourceCommon() : clang::ExternalASTSource()
 {
-    m_magic = ClangExternalASTSourceCommon_MAGIC;
-    
     g_TotalSizeOfMetadata += m_metadata.size();
+    GetSourceMap()[this] = this;
 }
 
 ClangExternalASTSourceCommon::~ClangExternalASTSourceCommon()
 {
+    GetSourceMap().erase(this);
     g_TotalSizeOfMetadata -= m_metadata.size();
 }
 
 ClangASTMetadata *
 ClangExternalASTSourceCommon::GetMetadata (const void *object)
 {
-    assert (m_magic == ClangExternalASTSourceCommon_MAGIC);
-    
     if (HasMetadata (object))
         return &m_metadata[object];
     else
@@ -42,8 +64,6 @@ ClangExternalASTSourceCommon::GetMetadata (const void *object)
 void
 ClangExternalASTSourceCommon::SetMetadata (const void *object, ClangASTMetadata &metadata)
 {
-    assert (m_magic == ClangExternalASTSourceCommon_MAGIC);
-    
     uint64_t orig_size = m_metadata.size();
     m_metadata[object] = metadata;
     uint64_t new_size = m_metadata.size();
@@ -53,8 +73,6 @@ ClangExternalASTSourceCommon::SetMetadata (const void *object, ClangASTMetadata
 bool
 ClangExternalASTSourceCommon::HasMetadata (const void *object)
 {
-    assert (m_magic == ClangExternalASTSourceCommon_MAGIC);
-
     return m_metadata.find(object) != m_metadata.end();
 }