Implemented linking to a dummy ASan runtime

src/IceASanInstrumentation.cpp

 //===- subzero/src/IceASanInstrumentation.cpp - ASan ------------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
 /// \brief Implements the AddressSanitizer instrumentation class.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "IceASanInstrumentation.h"
 
 #include "IceBuildDefs.h"
+#include "IceCfgNode.h"
 #include "IceGlobalInits.h"
+#include "IceInst.h"
 
 #include <sstream>
 
 namespace Ice {
 
 namespace {
 constexpr SizeT RzSize = 32;
 const std::string RzPrefix = "__$rz";
 const llvm::NaClBitcodeRecord::RecordVector RzContents =
     llvm::NaClBitcodeRecord::RecordVector(RzSize, 'R');
@@ skipping 73 matching lines @@
     Rz->addInitializer(
         VariableDeclaration::ZeroInitializer::create(List, RzSize));
   }
   Rz->setIsConstant(Global->getIsConstant());
   RzArray->addInitializer(VariableDeclaration::RelocInitializer::create(
       List, Rz, RelocOffsetArray(0)));
   ++RzArraySize;
   return Rz;
 }
 
+void ASanInstrumentation::instrumentStart(Cfg *Func) {
+  Constant *ShadowMemInit =
+      Ctx->getConstantExternSym(Ctx->getGlobalString("__asan_init"));
+  constexpr SizeT NumArgs = 0;
+  constexpr Variable *Void = nullptr;
+  constexpr bool NoTailCall = false;
+
+  auto *Call = InstCall::create(Func, NumArgs, Void, ShadowMemInit, NoTailCall);
+  Func->getEntryNode()->getInsts().push_front(Call);
+}
+
 } // end of namespace Ice