Move a few more convenience factory functions from Constant to LLVMContext.

[oota-llvm.git] / include / llvm / Constant.h

diff --git a/include/llvm/Constant.h b/include/llvm/Constant.h
index b0a130f81e4773e8aa80f6dd53a783c95c802860..3dc5881bdf4bf4f37fc9c4a8f0afc34448e0278f 100644 (file)
--- a/include/llvm/Constant.h
+++ b/include/llvm/Constant.h
@@ -18,6 +18,21 @@
 
 namespace llvm {
   template<typename T> class SmallVectorImpl;
+  class LLVMContext;
+
+  /// If object contains references to other objects, then relocations are
+  /// usually required for emission of such object (especially in PIC mode). One
+  /// usually distinguishes local and global relocations. Local relocations are
+  /// made wrt objects in the same module and these objects have local (internal
+  /// or private) linkage. Global relocations are made wrt externally visible
+  /// objects. In most cases local relocations can be resolved via so-called
+  /// 'pre-link' technique.
+  namespace Reloc {
+    const unsigned None   = 0;
+    const unsigned Local  = 1 << 0; ///< Local relocations are required
+    const unsigned Global = 1 << 1; ///< Global relocations are required
+    const unsigned LocalOrGlobal = Local | Global;
+  }
 
 /// This is an important base class in LLVM. It provides the common facilities
 /// of all constant values in an LLVM program. A constant is a value that is
@@ -45,26 +60,23 @@ protected:
 
   void destroyConstantImpl();
 public:
-  /// Static constructor to get a '0' constant of arbitrary type...
-  ///
-  static Constant *getNullValue(const Type *Ty);
-
-  /// Static constructor to get a '-1' constant.  This supports integers and
-  /// vectors.
-  ///
-  static Constant *getAllOnesValue(const Type *Ty);
-  
   /// isNullValue - Return true if this is the value that would be returned by
   /// getNullValue.
   virtual bool isNullValue() const = 0;
 
+  /// isNegativeZeroValue - Return true if the value is what would be returned 
+  /// by getZeroValueForNegation.
+  virtual bool isNegativeZeroValue() const { return isNullValue(); }
+
   /// canTrap - Return true if evaluation of this constant could trap.  This is
   /// true for things like constant expressions that could divide by zero.
   bool canTrap() const;
 
-  /// ContaintsRelocations - Return true if the constant value contains
-  /// relocations which cannot be resolved at compile time.
-  bool ContainsRelocations() const;
+  /// ContainsRelocations - Return true if the constant value contains
+  /// relocations which cannot be resolved at compile time. Note that answer is
+  /// not exclusive: there can be possibility that relocations of other kind are
+  /// required as well.
+  bool ContainsRelocations(unsigned Kind = Reloc::LocalOrGlobal) const;
 
   // Specialize get/setOperand for Constants as their operands are always
   // constants as well.
@@ -82,7 +94,8 @@ public:
   /// type, returns the elements of the vector in the specified smallvector.
   /// This handles breaking down a vector undef into undef elements, etc.  For
   /// constant exprs and other cases we can't handle, we return an empty vector.
-  void getVectorElements(SmallVectorImpl<Constant*> &Elts) const;
+  void getVectorElements(LLVMContext &Context, 
+                         SmallVectorImpl<Constant*> &Elts) const;
 
   /// destroyConstant - Called if some element of this constant is no longer
   /// valid.  At this point only other constants may be on the use_list for this