Ian/instruction carry lifter (#615)

* add lifter field

* arch has intrinsics

* use insn lifter in trace lifter

* limit default lifters to ops only

* init lifters

* pass arch in tests

* fix bug in swap

* stop using archbase decode in sleigh arches

Author: 2over12

bin/lift/Lift.cpp

@@ -269,7 +269,7 @@ int main(int argc, char *argv[]) {
 
   auto inst_lifter = arch->DefaultLifter(intrinsics);
 
-  remill::TraceLifter trace_lifter(*inst_lifter.get(), manager);
+  remill::TraceLifter trace_lifter(arch.get(), manager);
 
   // Lift all discoverable traces starting from `--entry_address` into
   // `module`.

include/remill/Arch/Arch.h

@@ -29,6 +29,7 @@
 #include <llvm/IR/DataLayout.h>
 #include <llvm/IR/IRBuilder.h>
 #include <remill/BC/InstructionLifter.h>
+#include <remill/BC/IntrinsicTable.h>
 
 #pragma clang diagnostic pop
 
@@ -200,6 +201,8 @@ class Arch {
   virtual llvm::StructType *RegisterWindowType(void) const = 0;
 
 
+  virtual const IntrinsicTable *GetInstrinsicTable(void) const = 0;
+
   virtual unsigned RegMdID(void) const = 0;
 
   // Apply `cb` to every register.
@@ -257,9 +260,9 @@ class Arch {
   void PrepareModuleDataLayout(llvm::Module *mod) const;
 
 
-  // TODO(Ian): This is kinda messy but only an arch currently knows if it is
-  //            sleigh or not and sleigh needs different lifting context etc.
-  virtual InstructionLifter::LifterPtr
+  // A default lifter does not know how to lift instructions. The default lifter allows
+  // the user to perform instruction/context independent lifting operations.
+  virtual OperandLifter::OpLifterPtr
   DefaultLifter(const remill::IntrinsicTable &intrinsics) const = 0;
 
   inline void

include/remill/Arch/ArchBase.h

@@ -33,6 +33,11 @@ struct Register;
 
 // Internal base architecture for all Remill-internal architectures.
 class ArchBase : public remill::Arch {
+ protected:
+  virtual bool ArchDecodeInstruction(uint64_t address,
+                                     std::string_view instr_bytes,
+                                     Instruction &inst) const = 0;
+
  public:
   using ArchPtr = std::unique_ptr<const Arch>;
 
@@ -64,11 +69,14 @@ class ArchBase : public remill::Arch {
   // Return information about a register, given its name.
   const Register *RegisterByName(std::string_view name) const final;
 
+  const IntrinsicTable *GetInstrinsicTable(void) const final;
+
   unsigned RegMdID(void) const final;
 
-  // TODO(Ian): This is kinda messy but only an arch currently knows if it is
-  //            sleigh or not and sleigh needs different lifting context etc.
-  InstructionLifter::LifterPtr
+  virtual bool DecodeInstruction(uint64_t address, std::string_view instr_bytes,
+                                 Instruction &inst) const override;
+
+  OperandLifter::OpLifterPtr
   DefaultLifter(const remill::IntrinsicTable &intrinsics) const override;
 
   // Get the state pointer and various other types from the `llvm::LLVMContext`
@@ -103,6 +111,7 @@ class ArchBase : public remill::Arch {
   mutable std::vector<std::unique_ptr<Register>> registers;
   mutable std::vector<const Register *> reg_by_offset;
   mutable std::unordered_map<std::string, const Register *> reg_by_name;
+  mutable std::unique_ptr<IntrinsicTable> instrinsics{nullptr};
 };
 
 }  // namespace remill

include/remill/Arch/Instruction.h

@@ -16,6 +16,8 @@
 
 #pragma once
 
+#include <remill/BC/InstructionLifter.h>
+
 #include <string>
 #include <variant>
 #include <vector>
@@ -349,7 +351,13 @@ class Instruction {
   Operand &EmplaceOperand(const Operand::ShiftRegister &op);
   Operand &EmplaceOperand(const Operand::Address &op);
 
+
+  const InstructionLifter::LifterPtr &GetLifter();
+
+  void SetLifter(InstructionLifter::LifterPtr lifter);
+
  private:
+  InstructionLifter::LifterPtr lifter;
   static constexpr auto kMaxNumExpr = 64u;
   OperandExpression exprs[kMaxNumExpr];
   unsigned next_expr_index{0};

include/remill/BC/InstructionLifter.h

@@ -51,12 +51,30 @@ enum LiftStatus {
   kLiftedInstruction
 };
 
+// Instruction independent lifting
+class OperandLifter {
+ public:
+  using OpLifterPtr = std::shared_ptr<OperandLifter>;
+
+  // Load the address of a register.
+  virtual std::pair<llvm::Value *, llvm::Type *>
+  LoadRegAddress(llvm::BasicBlock *block, llvm::Value *state_ptr,
+                 std::string_view reg_name) const = 0;
+
+  // Load the value of a register.
+  virtual llvm::Value *LoadRegValue(llvm::BasicBlock *block,
+                                    llvm::Value *state_ptr,
+                                    std::string_view reg_name) const = 0;
+
+  virtual llvm::Type *GetMemoryType() = 0;
+};
+
 // Wraps the process of lifting an instruction into a block. This resolves
 // the intended instruction target to a function, and ensures that the function
 // is called with the appropriate arguments.
-class InstructionLifter {
+class InstructionLifter : public OperandLifter {
  public:
-  using LifterPtr = std::unique_ptr<InstructionLifter>;
+  using LifterPtr = std::shared_ptr<InstructionLifter>;
 
   virtual ~InstructionLifter(void);
 
@@ -83,17 +101,17 @@ class InstructionLifter {
   // Load the address of a register.
   std::pair<llvm::Value *, llvm::Type *>
   LoadRegAddress(llvm::BasicBlock *block, llvm::Value *state_ptr,
-                 std::string_view reg_name) const;
+                 std::string_view reg_name) const override final;
 
   // Load the value of a register.
   llvm::Value *LoadRegValue(llvm::BasicBlock *block, llvm::Value *state_ptr,
-                            std::string_view reg_name) const;
+                            std::string_view reg_name) const override final;
 
   // Clear out the cache of the current register values/addresses loaded.
   void ClearCache(void) const;
 
 
-  llvm::Type *GetMemoryType();
+  virtual llvm::Type *GetMemoryType() override final;
 
  protected:
   // Lift an operand to an instruction.

include/remill/BC/TraceLifter.h

@@ -86,10 +86,10 @@ class TraceLifter {
  public:
   ~TraceLifter(void);
 
-  inline TraceLifter(InstructionLifter &inst_lifter_, TraceManager &manager_)
-      : TraceLifter(&inst_lifter_, &manager_) {}
+  inline TraceLifter(const Arch *arch_, TraceManager &manager_)
+      : TraceLifter(arch_, &manager_) {}
 
-  TraceLifter(InstructionLifter *inst_lifter_, TraceManager *manager_);
+  TraceLifter(const Arch *arch_, TraceManager *manager_);
 
   static void NullCallback(uint64_t, llvm::Function *);
 

lib/Arch/AArch32/Arch.h

@@ -26,8 +26,8 @@ class AArch32Arch final : public AArch32ArchBase {
 
   virtual ~AArch32Arch(void);
 
-  bool DecodeInstruction(uint64_t address, std::string_view inst_bytes,
-                         Instruction &inst) const override;
+  bool ArchDecodeInstruction(uint64_t address, std::string_view inst_bytes,
+                             Instruction &inst) const override;
 
  private:
   AArch32Arch(void) = delete;