Add passes for applying SFI sandboxing at the LLVM IR level

lib/Transforms/NaCl/FlattenGlobals.cpp

 //===- FlattenGlobals.cpp - Flatten global variable initializers-----------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This pass converts initializers for global variables into a
@@ skipping 118 matching lines @@
     *ResultOffset = 0;
   } else if (ConstantInt *CI = dyn_cast<ConstantInt>(Val)) {
     *ResultGlobal = NULL;
     *ResultOffset = CI->getZExtValue();
   } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Val)) {
     ExpandConstant(DL, CE->getOperand(0), ResultGlobal, ResultOffset);
     if (CE->getOpcode() == Instruction::GetElementPtr) {
       SmallVector<Value *, 8> Indexes(CE->op_begin() + 1, CE->op_end());
       *ResultOffset += DL->getIndexedOffset(CE->getOperand(0)->getType(),
                                             Indexes);
+    } else if (CE->getOpcode() == Instruction::Add &&
+               isa<ConstantInt>(CE->getOperand(1))) {
+      *ResultOffset += cast<ConstantInt>(CE->getOperand(1))->getZExtValue();
     } else if (CE->getOpcode() == Instruction::BitCast ||
                CE->getOpcode() == Instruction::IntToPtr) {
       // Nothing more to do.
     } else if (CE->getOpcode() == Instruction::PtrToInt) {
       if (Val->getType()->getIntegerBitWidth() < DL->getPointerSizeInBits()) {
         errs() << "Not handled: " << *CE << "\n";
         report_fatal_error("FlattenGlobals: a ptrtoint that truncates "
                            "a pointer is not allowed");
       }
     } else {
@@ skipping 144 matching lines @@
           ConstantExpr::getBitCast(NewGlobal, Global->getType()));
     Global->eraseFromParent();
   }
   return Modified;
 
 }
 
 ModulePass *llvm::createFlattenGlobalsPass() {
   return new FlattenGlobals();
 }