Change getConstantValue to throw an exception on error, not return null

llvm-svn: 8988

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/Bytecode/Reader/Reader.cpp b/llvm/lib/Bytecode/Reader/Reader.cpp
index c515c1575c5..bf2b0118a35 100644
--- a/llvm/lib/Bytecode/Reader/Reader.cpp
+++ b/llvm/lib/Bytecode/Reader/Reader.cpp
@@ -164,7 +164,10 @@ BasicBlock *BytecodeParser::getBasicBlock(unsigned ID) {
 ///
 Constant *BytecodeParser::getConstantValue(const Type *Ty, unsigned Slot) {
   if (Value *V = getValue(Ty, Slot, false))
-    return dyn_cast<Constant>(V);      // If we already have the value parsed...
+    if (Constant *C = dyn_cast<Constant>(V))
+      return C;   // If we already have the value parsed, just return it
+    else
+      throw std::string("Reference of a value is expected to be a constant!");
 
   std::pair<const Type*, unsigned> Key(Ty, Slot);
   GlobalRefsType::iterator I = GlobalRefs.lower_bound(Key);