Subzero, MIPS32: Sandbox initial patch

src/IceTargetLoweringMIPS32.h

 //===- subzero/src/IceTargetLoweringMIPS32.h - MIPS32 lowering ---*- C++-*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 562 matching lines @@
   void _xor(Variable *Dest, Variable *Src0, Variable *Src1) {
     Context.insert<InstMIPS32Xor>(Dest, Src0, Src1);
   }
 
   void _xori(Variable *Dest, Variable *Src, uint32_t Imm) {
     Context.insert<InstMIPS32Xori>(Dest, Src, Imm);
   }
 
   void lowerArguments() override;
 
+  class Sandboxer {
+    Sandboxer() = delete;
+    Sandboxer(const Sandboxer &) = delete;
+    Sandboxer &operator=(const Sandboxer &) = delete;
+
+  public:
+    explicit Sandboxer(
+        TargetMIPS32 *Target,
+        InstBundleLock::Option BundleOption = InstBundleLock::Opt_None);
+    ~Sandboxer();
+
+    void addiu_sp(uint32_t StackOffset);
+    void lw(Variable *Dest, OperandMIPS32Mem *Mem);
+    void sw(Variable *Dest, OperandMIPS32Mem *Mem);
+    void ret(Variable *RetAddr, Variable *RetValue);
+    void reset_sp(Variable *Src);
+    InstMIPS32Call *jal(Variable *ReturnReg, Operand *CallTarget);
+
+  private:
+    TargetMIPS32 *const Target;
+    const InstBundleLock::Option BundleOption;
+    std::unique_ptr<AutoBundle> Bundler;
+
+    void createAutoBundle();
+  };
+
+  const bool NeedSandboxing;
+
   /// Make a pass through the SortedSpilledVariables and actually assign stack
   /// slots. SpillAreaPaddingBytes takes into account stack alignment padding.
   /// The SpillArea starts after that amount of padding. This matches the scheme
   /// in getVarStackSlotParams, where there may be a separate multi-block global
   /// var spill area and a local var spill area.
   void assignVarStackSlots(VarList &SortedSpilledVariables,
                            size_t SpillAreaPaddingBytes,
                            size_t SpillAreaSizeBytes,
                            size_t GlobalsAndSubsequentPaddingSize);
 
@@ skipping 407 matching lines @@
   uint32_t Flags1 = AFL_FLAGS1_ODDSPREG;
   uint32_t Flags2 = AFL_FLAGS2_NONE;
 
   MipsABIFlagsSection() = default;
 };
 
 } // end of namespace MIPS32
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGMIPS32_H