constify some methods and add a new Constant::getAggregateElement

helper method for the common operation of extracting an element
out of a constant aggregate.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148931 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 15 insertions, 8 deletions

diff --git a/include/llvm/Constant.h b/include/llvm/Constant.h
index 3ce8d2c243..f7d4dd2d32 100644
--- a/include/llvm/Constant.h
+++ b/include/llvm/Constant.h
@@ -97,6 +97,13 @@ public:
   /// constant exprs and other cases we can't handle, we return an empty vector.
   void getVectorElements(SmallVectorImpl<Constant*> &Elts) const;
 
+  /// getAggregateElement - For aggregates (struct/array/vector) return the
+  /// constant that corresponds to the specified element if possible, or null if
+  /// not.  This can return null if the element index is a ConstantExpr, or if
+  /// 'this' is a constant expr.
+  Constant *getAggregateElement(unsigned Elt) const;
+  Constant *getAggregateElement(Constant *Elt) 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
   /// constant.  Any constants on our Use list must also be destroy'd.  The
diff --git a/include/llvm/Constants.h b/include/llvm/Constants.h
index 1823f1d49e..a685ccc31c 100644
--- a/include/llvm/Constants.h
+++ b/include/llvm/Constants.h
@@ -316,19 +316,19 @@ public:
 
   /// getSequentialElement - If this CAZ has array or vector type, return a zero
   /// with the right element type.
-  Constant *getSequentialElement();
+  Constant *getSequentialElement() const;
 
   /// getStructElement - If this CAZ has struct type, return a zero with the
   /// right element type for the specified element.
-  Constant *getStructElement(unsigned Elt);
+  Constant *getStructElement(unsigned Elt) const;
 
   /// getElementValue - Return a zero of the right value for the specified GEP
   /// index.
-  Constant *getElementValue(Constant *C);
+  Constant *getElementValue(Constant *C) const;
 
   /// getElementValue - Return a zero of the right value for the specified GEP
   /// index.
-  Constant *getElementValue(unsigned Idx);
+  Constant *getElementValue(unsigned Idx) const;
 
   /// Methods for support type inquiry through isa, cast, and dyn_cast:
   ///
@@ -1157,19 +1157,19 @@ public:
 
   /// getSequentialElement - If this Undef has array or vector type, return a
   /// undef with the right element type.
-  UndefValue *getSequentialElement();
+  UndefValue *getSequentialElement() const;
   
   /// getStructElement - If this undef has struct type, return a undef with the
   /// right element type for the specified element.
-  UndefValue *getStructElement(unsigned Elt);
+  UndefValue *getStructElement(unsigned Elt) const;
   
   /// getElementValue - Return an undef of the right value for the specified GEP
   /// index.
-  UndefValue *getElementValue(Constant *C);
+  UndefValue *getElementValue(Constant *C) const;
 
   /// getElementValue - Return an undef of the right value for the specified GEP
   /// index.
-  UndefValue *getElementValue(unsigned Idx);
+  UndefValue *getElementValue(unsigned Idx) const;
 
   virtual void destroyConstant();