Add support for fopen/fclose. Specifically with fopen, we were marking all of the

operands as incomplete, though fopen is known to only read them.  This just adds
fclose for symmetry, though it doesn't gain anything.  This makes the dsgraphs for
181.mcf much more precise.

llvm-svn: 11390

lib/Analysis/DataStructure/Local.cpp

@@ -493,6 +493,33 @@ void GraphBuilder::visitCallSite(CallSite CS) {
           if (DSNode *N = H.getNode())
             N->setModifiedMarker();
           return;
+        } else if (F->getName() == "fopen" && CS.arg_end()-CS.arg_begin() == 2){
+          // fopen reads the mode argument strings.
+          CallSite::arg_iterator AI = CS.arg_begin();
+          DSNodeHandle Path = getValueDest(**AI);
+          DSNodeHandle Mode = getValueDest(**++AI);
+          if (DSNode *N = Path.getNode()) N->setReadMarker();
+          if (DSNode *N = Mode.getNode()) N->setReadMarker();
+          
+          // fopen allocates in an unknown way and writes to the file
+          // descriptor.  Also, merge the allocated type into the node.
+          DSNodeHandle Result = getValueDest(*CS.getInstruction());
+          Result.getNode()->setModifiedMarker()->setUnknownNodeMarker();
+          const Type *RetTy = F->getFunctionType()->getReturnType();
+          if (const PointerType *PTy = dyn_cast<PointerType>(RetTy))
+            Result.getNode()->mergeTypeInfo(PTy->getElementType(),
+                                            Result.getOffset());
+          return;
+        } else if (F->getName() == "fclose" && CS.arg_end()-CS.arg_begin() ==1){
+          // fclose reads and deallocates the memory in an unknown way for the
+          // file descriptor.  It merges the FILE type into the descriptor.
+          DSNodeHandle H = getValueDest(**CS.arg_begin());
+          H.getNode()->setReadMarker()->setUnknownNodeMarker();
+          
+          const Type *ArgTy = *F->getFunctionType()->param_begin();
+          if (const PointerType *PTy = dyn_cast<PointerType>(ArgTy))
+            H.getNode()->mergeTypeInfo(PTy->getElementType(), H.getOffset());
+          return;
         }
       }