1 files changed, 70 insertions, 1 deletions
diff --git a/CodeGen/CodeGenTypes.h b/CodeGen/CodeGenTypes.h
index 1f6cbd8701..998175537b 100644
--- a/CodeGen/CodeGenTypes.h
+++ b/CodeGen/CodeGenTypes.h
@@ -15,6 +15,7 @@
 #define CODEGEN_CODEGENTYPES_H
 
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
 #include <vector>
 
 namespace llvm {
@@ -28,8 +29,57 @@ namespace clang {
   class TargetInfo;
   class QualType;
   class FunctionTypeProto;
-  
+ class FieldDecl;
+
 namespace CodeGen {
+  class CodeGenTypes;
+
+  /// RecordOrganizer - This helper class, used by RecordLayoutInfo, layouts 
+  /// structs and unions. It manages transient information used during layout.
+  /// FIXME : At the moment assume 
+  ///    - one to one mapping between AST FieldDecls and 
+  ///      llvm::StructType elements.
+  ///    - Ignore bit fields
+  ///    - Ignore field aligments
+  ///    - Ignore packed structs
+  class RecordOrganizer {
+  public:
+    RecordOrganizer() : STy(NULL) {}
+    
+    /// addField - Add new field.
+    void addField(const FieldDecl *FD);
+
+    /// layoutFields - Do the actual work and lay out all fields. Create
+    /// corresponding llvm struct type.  This should be invoked only after
+    /// all fields are added.
+    void layoutFields(CodeGenTypes &CGT);
+
+    /// getLLVMType - Return associated llvm struct type. This may be NULL
+    /// if fields are not laid out.
+    llvm::Type *getLLVMType() {
+      return STy;
+    }
+
+  private:
+    llvm::Type *STy;
+    llvm::SmallVector<const FieldDecl *, 8> FieldDecls;
+  };
+
+  /// RecordLayoutInfo - This class handles struct and union layout info while 
+  /// lowering AST types to LLVM types.
+  class RecordLayoutInfo {
+    RecordLayoutInfo(); // DO NOT IMPLEMENT
+  public:
+    RecordLayoutInfo(RecordOrganizer *RO);
+
+    /// getLLVMType - Return llvm type associated with this record.
+    llvm::Type *getLLVMType() {
+      return STy;
+    }
+
+  private:
+    llvm::Type *STy;
+  };
   
 /// CodeGenTypes - This class organizes the cross-module state that is used
 /// while lowering AST types to LLVM types.
@@ -39,14 +89,33 @@ class CodeGenTypes {
   llvm::Module& TheModule;
   
   llvm::DenseMap<const TagDecl*, llvm::Type*> TagDeclTypes;
+
+  /// RecordLayouts - This maps llvm struct type with corresponding 
+  /// record layout info. 
+  llvm::DenseMap<const llvm::Type*, RecordLayoutInfo *> RecordLayouts;
+
+  /// FieldInfo - This maps struct field with corresponding llvm struct type
+  /// field no. This info is populated by record organizer.
+  llvm::DenseMap<const FieldDecl *, unsigned> FieldInfo;
+
 public:
   CodeGenTypes(ASTContext &Ctx, llvm::Module &M);
+  ~CodeGenTypes();
   
   TargetInfo &getTarget() const { return Target; }
   
   const llvm::Type *ConvertType(QualType T);
   void DecodeArgumentTypes(const FunctionTypeProto &FTP, 
                            std::vector<const llvm::Type*> &ArgTys);
+
+  RecordLayoutInfo *getRecordLayoutInfo(const llvm::Type*);
+  
+  /// getLLVMFieldNo - Return llvm::StructType element number
+  /// that corresponds to the field FD.
+  unsigned getLLVMFieldNo(const FieldDecl *FD);
+
+  /// addFieldInfo - Assign field number to field FD.
+  void addFieldInfo(const FieldDecl *FD, unsigned No);
 };
 
 }  // end namespace CodeGen