lldb/Expression/Expression.h

0001 //===-- Expression.h --------------------------------------------*- C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef LLDB_EXPRESSION_EXPRESSION_H
0010 #define LLDB_EXPRESSION_EXPRESSION_H
0011
0012 #include <map>
0013 #include <string>
0014 #include <vector>
0015
0016
0017 #include "lldb/Expression/ExpressionTypeSystemHelper.h"
0018 #include "lldb/lldb-forward.h"
0019 #include "lldb/lldb-private.h"
0020
0021 namespace lldb_private {
0022
0023 /// \class Expression Expression.h "lldb/Expression/Expression.h" Encapsulates
0024 /// a single expression for use in lldb
0025 ///
0026 /// LLDB uses expressions for various purposes, notably to call functions
0027 /// and as a backend for the expr command.  Expression encapsulates the
0028 /// objects needed to parse and interpret or JIT an expression.  It uses the
0029 /// expression parser appropriate to the language of the expression to produce
0030 /// LLVM IR from the expression.
0031 class Expression {
0032 public:
0033   enum ResultType { eResultTypeAny, eResultTypeId };
0034
0035   Expression(Target &target);
0036
0037   Expression(ExecutionContextScope &exe_scope);
0038
0039   /// Destructor
0040   virtual ~Expression() = default;
0041
0042   /// Return the string that the parser should parse.  Must be a full
0043   /// translation unit.
0044   virtual const char *Text() = 0;
0045
0046   /// Return the function name that should be used for executing the
0047   /// expression.  Text() should contain the definition of this function.
0048   virtual const char *FunctionName() = 0;
0049
0050   /// Return the language that should be used when parsing.
0051   virtual SourceLanguage Language() const { return {}; }
0052
0053   /// Return the Materializer that the parser should use when registering
0054   /// external values.
0055   virtual Materializer *GetMaterializer() { return nullptr; }
0056
0057   /// Return the desired result type of the function, or eResultTypeAny if
0058   /// indifferent.
0059   virtual ResultType DesiredResultType() const { return eResultTypeAny; }
0060
0061   /// Flags
0062
0063   /// Return true if validation code should be inserted into the expression.
0064   virtual bool NeedsValidation() = 0;
0065
0066   /// Return true if external variables in the expression should be resolved.
0067   virtual bool NeedsVariableResolution() = 0;
0068
0069   virtual EvaluateExpressionOptions *GetOptions() { return nullptr; };
0070
0071   /// Return the address of the function's JIT-compiled code, or
0072   /// LLDB_INVALID_ADDRESS if the function is not JIT compiled
0073   lldb::addr_t StartAddress() { return m_jit_start_addr; }
0074
0075   /// Called to notify the expression that it is about to be executed.
0076   virtual void WillStartExecuting() {}
0077
0078   /// Called to notify the expression that its execution has finished.
0079   virtual void DidFinishExecuting() {}
0080
0081   virtual ExpressionTypeSystemHelper *GetTypeSystemHelper() { return nullptr; }
0082
0083   // LLVM RTTI support
0084   virtual bool isA(const void *ClassID) const = 0;
0085
0086 protected:
0087   lldb::TargetWP m_target_wp; /// Expression's always have to have a target...
0088   lldb::ProcessWP m_jit_process_wp; /// An expression might have a process, but
0089                                     /// it doesn't need to (e.g. calculator
0090                                     /// mode.)
0091   lldb::addr_t m_jit_start_addr; ///< The address of the JITted function within
0092                                  ///the JIT allocation.  LLDB_INVALID_ADDRESS if
0093                                  ///invalid.
0094   lldb::addr_t m_jit_end_addr;   ///< The address of the JITted function within
0095                                  ///the JIT allocation.  LLDB_INVALID_ADDRESS if
0096                                  ///invalid.
0097 };
0098
0099 } // namespace lldb_private
0100
0101 #endif // LLDB_EXPRESSION_EXPRESSION_H