Add llvm::Metadata to manage metadata used in a context.

This interface will be used to attach metadata with an instruction.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82060 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 51 insertions, 1 deletions

diff --git a/include/llvm/LLVMContext.h b/include/llvm/LLVMContext.h
index 56a640e..5e8cd1a 100644
--- a/include/llvm/LLVMContext.h
+++ b/include/llvm/LLVMContext.h
@@ -18,7 +18,7 @@
 namespace llvm {
 
 class LLVMContextImpl;
-
+class Metadata;
 /// This is an important class for using LLVM in a threaded context.  It
 /// (opaquely) owns and manages the core "global" data of LLVM's core 
 /// infrastructure, including the type and constant uniquing tables.
@@ -30,6 +30,7 @@ class LLVMContext {
   void operator=(LLVMContext&);
 public:
   LLVMContextImpl* pImpl;
+  Metadata &getMetadata();
   bool RemoveDeadMetadata();
   LLVMContext();
   ~LLVMContext();
diff --git a/include/llvm/Metadata.h b/include/llvm/Metadata.h
index 0844006..66a10a8 100644
--- a/include/llvm/Metadata.h
+++ b/include/llvm/Metadata.h
@@ -22,12 +22,16 @@
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/ilist_node.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ValueHandle.h"
 
 namespace llvm {
 class Constant;
+class Instruction;
 class LLVMContext;
 
 //===----------------------------------------------------------------------===//
@@ -300,6 +304,48 @@ public:
   }
 };
 
+//===----------------------------------------------------------------------===//
+/// Metadata -
+/// Metadata manages metadata used in a context.
+
+/// MDKindID - This id identifies metadata kind the metadata store. Valid
+/// ID values are 1 or higher. This ID is set by RegisterMDKind.
+typedef unsigned MDKindID;
+class Metadata {
+private:
+  typedef std::pair<MDKindID, WeakVH> MDPairTy;
+  typedef SmallVector<MDPairTy, 2> MDMapTy;
+  typedef DenseMap<const Instruction *, MDMapTy> MDStoreTy;
+
+  /// MetadataStore - Collection of metadata used in this context.
+  MDStoreTy MetadataStore;
+
+  /// MDHandlerNames - Map to hold metadata handler names.
+  StringMap<unsigned> MDHandlerNames;
+
+public:
+
+  /// RegisterMDKind - Register a new metadata kind and return its ID.
+  /// A metadata kind can be registered only once. 
+  MDKindID RegisterMDKind(const char *Name);
+
+  /// getMDKind - Return metadata kind. If the requested metadata kind
+  /// is not registered then return 0.
+  MDKindID getMDKind(const char *Name);
+
+  /// getMD - Get the metadata of given kind attached with an Instruction.
+  /// If the metadata is not found then return 0.
+  MDNode *getMD(MDKindID Kind, const Instruction *Inst);
+
+  /// setMD - Attach the metadata of given kind with an Instruction.
+  void setMD(MDKindID Kind, MDNode *Node, Instruction *Inst);
+  
+  /// ValueIsDeleted - This handler is used to update metadata store
+  /// when a value is deleted.
+  void ValueIsDeleted(Value *V) {}
+  void ValueIsDeleted(const Instruction *Inst);
+};
+
 } // end llvm namespace
 
 #endif
diff --git a/include/llvm/Value.h b/include/llvm/Value.h
index 5aa2ea0..87c4dc2 100644
--- a/include/llvm/Value.h
+++ b/include/llvm/Value.h
@@ -42,6 +42,7 @@ class raw_ostream;
 class AssemblyAnnotationWriter;
 class ValueHandleBase;
 class LLVMContext;
+class Metadata;
 
 //===----------------------------------------------------------------------===//
 //                                 Value Class
@@ -63,6 +64,7 @@ class LLVMContext;
 class Value {
   const unsigned char SubclassID;   // Subclass identifier (for isa/dyn_cast)
   unsigned char HasValueHandle : 1; // Has a ValueHandle pointing to this?
+  unsigned char HasMetadata : 1;    // Has a metadata attached to this ?
 protected:
   /// SubclassOptionalData - This member is similar to SubclassData, however it
   /// is for holding information which may be used to aid optimization, but
@@ -81,6 +83,7 @@ private:
   friend class ValueSymbolTable; // Allow ValueSymbolTable to directly mod Name.
   friend class SymbolTable;      // Allow SymbolTable to directly poke Name.
   friend class ValueHandleBase;
+  friend class Metadata;
   friend class AbstractTypeUser;
   ValueName *Name;