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//===-- IRToDWARF.h ---------------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef liblldb_IRToDWARF_h_
#define liblldb_IRToDWARF_h_
#include "llvm/Pass.h"
#include "llvm/IR/LegacyPassManager.h"
#include "lldb/lldb-public.h"
class Relocator;
//----------------------------------------------------------------------
/// @class IRToDWARF IRToDWARF.h "lldb/Expression/IRToDWARF.h"
/// @brief Transforms the IR for a function into a DWARF location expression
///
/// Once an expression has been parsed and converted to IR, it can run
/// in two contexts: interpreted by LLDB as a DWARF location expression,
/// or compiled by the JIT and inserted into the target process for
/// execution.
///
/// IRToDWARF makes the first possible, by traversing the control flow
/// graph and writing the code for each basic block out as location
/// expression bytecode. To ensure that the links between the basic blocks
/// remain intact, it uses a relocator that records the location of every
/// location expression instruction that has a relocatable operand, the
/// target of that operand (as a basic block), and the mapping of each basic
/// block to an actual location. After all code has been written out, the
/// relocator post-processes it and performs all necessary relocations.
//----------------------------------------------------------------------
class IRToDWARF : public llvm::ModulePass
{
public:
//------------------------------------------------------------------
/// Constructor
///
/// @param[in] local_vars
/// A list of variables to populate with the local variables this
/// expression uses.
///
/// @param[in] decl_map
/// The list of externally-referenced variables for the expression,
/// for use in looking up globals.
///
/// @param[in] stream
/// The stream to dump DWARF bytecode onto.
///
/// @param[in] func_name
/// The name of the function to translate to DWARF.
//------------------------------------------------------------------
IRToDWARF(lldb_private::ClangExpressionVariableList &local_vars,
lldb_private::ClangExpressionDeclMap *decl_map,
lldb_private::StreamString &strm,
const char* func_name = "$__lldb_expr");
//------------------------------------------------------------------
/// Destructor
//------------------------------------------------------------------
virtual ~IRToDWARF();
//------------------------------------------------------------------
/// Run this IR transformer on a single module
///
/// @param[in] M
/// The module to run on. This module is searched for the function
/// $__lldb_expr, and that function is converted to a location
/// expression.
///
/// @return
/// True on success; false otherwise
//------------------------------------------------------------------
bool runOnModule(llvm::Module &M);
//------------------------------------------------------------------
/// Interface stub
//------------------------------------------------------------------
void assignPassManager(llvm::PMStack &PMS,
llvm::PassManagerType T = llvm::PMT_ModulePassManager);
//------------------------------------------------------------------
/// Returns PMT_ModulePassManager
//------------------------------------------------------------------
llvm::PassManagerType getPotentialPassManagerType() const;
private:
//------------------------------------------------------------------
/// Run this IR transformer on a single basic block
///
/// @param[in] BB
/// The basic block to transform.
///
/// @param[in] Relocator
/// The relocator to use when registering branches.
///
/// @return
/// True on success; false otherwise
//------------------------------------------------------------------
bool runOnBasicBlock(llvm::BasicBlock &BB, Relocator &Relocator);
std::string m_func_name; ///< The name of the function to translate
lldb_private::ClangExpressionVariableList &m_local_vars; ///< The list of local variables to populate while transforming
lldb_private::ClangExpressionDeclMap *m_decl_map; ///< The list of external variables
lldb_private::StreamString &m_strm; ///< The stream to write bytecode to
};
#endif
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