| //===-- DWARFExpression.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_DWARFExpression_h_ |
| #define liblldb_DWARFExpression_h_ |
| |
| #include "lldb/Core/Address.h" |
| #include "lldb/Core/Disassembler.h" |
| #include "lldb/Core/Scalar.h" |
| #include "lldb/Utility/DataExtractor.h" |
| #include "lldb/Utility/Status.h" |
| #include "lldb/lldb-private.h" |
| #include <functional> |
| |
| class DWARFUnit; |
| |
| namespace lldb_private { |
| |
| //---------------------------------------------------------------------- |
| /// @class DWARFExpression DWARFExpression.h |
| /// "lldb/Expression/DWARFExpression.h" Encapsulates a DWARF location |
| /// expression and interprets it. |
| /// |
| /// DWARF location expressions are used in two ways by LLDB. The first |
| /// use is to find entities specified in the debug information, since their |
| /// locations are specified in precisely this language. The second is to |
| /// interpret expressions without having to run the target in cases where the |
| /// overhead from copying JIT-compiled code into the target is too high or |
| /// where the target cannot be run. This class encapsulates a single DWARF |
| /// location expression or a location list and interprets it. |
| //---------------------------------------------------------------------- |
| class DWARFExpression { |
| public: |
| enum LocationListFormat : uint8_t { |
| NonLocationList, // Not a location list |
| RegularLocationList, // Location list format used in non-split dwarf files |
| SplitDwarfLocationList, // Location list format used in split dwarf files |
| }; |
| |
| //------------------------------------------------------------------ |
| /// Constructor |
| //------------------------------------------------------------------ |
| explicit DWARFExpression(DWARFUnit *dwarf_cu); |
| |
| //------------------------------------------------------------------ |
| /// Constructor |
| /// |
| /// @param[in] data |
| /// A data extractor configured to read the DWARF location expression's |
| /// bytecode. |
| /// |
| /// @param[in] data_offset |
| /// The offset of the location expression in the extractor. |
| /// |
| /// @param[in] data_length |
| /// The byte length of the location expression. |
| //------------------------------------------------------------------ |
| DWARFExpression(lldb::ModuleSP module, const DataExtractor &data, |
| DWARFUnit *dwarf_cu, lldb::offset_t data_offset, |
| lldb::offset_t data_length); |
| |
| //------------------------------------------------------------------ |
| /// Copy constructor |
| //------------------------------------------------------------------ |
| DWARFExpression(const DWARFExpression &rhs); |
| |
| //------------------------------------------------------------------ |
| /// Destructor |
| //------------------------------------------------------------------ |
| virtual ~DWARFExpression(); |
| |
| //------------------------------------------------------------------ |
| /// Print the description of the expression to a stream |
| /// |
| /// @param[in] s |
| /// The stream to print to. |
| /// |
| /// @param[in] level |
| /// The level of verbosity to use. |
| /// |
| /// @param[in] location_list_base_addr |
| /// If this is a location list based expression, this is the |
| /// address of the object that owns it. NOTE: this value is |
| /// different from the DWARF version of the location list base |
| /// address which is compile unit relative. This base address |
| /// is the address of the object that owns the location list. |
| /// |
| /// @param[in] abi |
| /// An optional ABI plug-in that can be used to resolve register |
| /// names. |
| //------------------------------------------------------------------ |
| void GetDescription(Stream *s, lldb::DescriptionLevel level, |
| lldb::addr_t location_list_base_addr, ABI *abi) const; |
| |
| //------------------------------------------------------------------ |
| /// Return true if the location expression contains data |
| //------------------------------------------------------------------ |
| bool IsValid() const; |
| |
| //------------------------------------------------------------------ |
| /// Return true if a location list was provided |
| //------------------------------------------------------------------ |
| bool IsLocationList() const; |
| |
| //------------------------------------------------------------------ |
| /// Search for a load address in the location list |
| /// |
| /// @param[in] process |
| /// The process to use when resolving the load address |
| /// |
| /// @param[in] addr |
| /// The address to resolve |
| /// |
| /// @return |
| /// True if IsLocationList() is true and the address was found; |
| /// false otherwise. |
| //------------------------------------------------------------------ |
| // bool |
| // LocationListContainsLoadAddress (Process* process, const Address &addr) |
| // const; |
| // |
| bool LocationListContainsAddress(lldb::addr_t loclist_base_addr, |
| lldb::addr_t addr) const; |
| |
| //------------------------------------------------------------------ |
| /// If a location is not a location list, return true if the location |
| /// contains a DW_OP_addr () opcode in the stream that matches \a file_addr. |
| /// If file_addr is LLDB_INVALID_ADDRESS, the this function will return true |
| /// if the variable there is any DW_OP_addr in a location that (yet still is |
| /// NOT a location list). This helps us detect if a variable is a global or |
| /// static variable since there is no other indication from DWARF debug |
| /// info. |
| /// |
| /// @param[in] op_addr_idx |
| /// The DW_OP_addr index to retrieve in case there is more than |
| /// one DW_OP_addr opcode in the location byte stream. |
| /// |
| /// @param[out] error |
| /// If the location stream contains unknown DW_OP opcodes or the |
| /// data is missing, \a error will be set to \b true. |
| /// |
| /// @return |
| /// LLDB_INVALID_ADDRESS if the location doesn't contain a |
| /// DW_OP_addr for \a op_addr_idx, otherwise a valid file address |
| //------------------------------------------------------------------ |
| lldb::addr_t GetLocation_DW_OP_addr(uint32_t op_addr_idx, bool &error) const; |
| |
| bool Update_DW_OP_addr(lldb::addr_t file_addr); |
| |
| bool ContainsThreadLocalStorage() const; |
| |
| bool LinkThreadLocalStorage( |
| lldb::ModuleSP new_module_sp, |
| std::function<lldb::addr_t(lldb::addr_t file_addr)> const |
| &link_address_callback); |
| |
| //------------------------------------------------------------------ |
| /// Make the expression parser read its location information from a given |
| /// data source. Does not change the offset and length |
| /// |
| /// @param[in] data |
| /// A data extractor configured to read the DWARF location expression's |
| /// bytecode. |
| //------------------------------------------------------------------ |
| void SetOpcodeData(const DataExtractor &data); |
| |
| //------------------------------------------------------------------ |
| /// Make the expression parser read its location information from a given |
| /// data source |
| /// |
| /// @param[in] module_sp |
| /// The module that defines the DWARF expression. |
| /// |
| /// @param[in] data |
| /// A data extractor configured to read the DWARF location expression's |
| /// bytecode. |
| /// |
| /// @param[in] data_offset |
| /// The offset of the location expression in the extractor. |
| /// |
| /// @param[in] data_length |
| /// The byte length of the location expression. |
| //------------------------------------------------------------------ |
| void SetOpcodeData(lldb::ModuleSP module_sp, const DataExtractor &data, |
| lldb::offset_t data_offset, lldb::offset_t data_length); |
| |
| //------------------------------------------------------------------ |
| /// Copy the DWARF location expression into a local buffer. |
| /// |
| /// It is a good idea to copy the data so we don't keep the entire object |
| /// file worth of data around just for a few bytes of location expression. |
| /// LLDB typically will mmap the entire contents of debug information files, |
| /// and if we use SetOpcodeData, it will get a shared reference to all of |
| /// this data for the and cause the object file to have to stay around. Even |
| /// worse, a very very large ".a" that contains one or more .o files could |
| /// end up being referenced. Location lists are typically small so even |
| /// though we are copying the data, it shouldn't amount to that much for the |
| /// variables we end up parsing. |
| /// |
| /// @param[in] module_sp |
| /// The module that defines the DWARF expression. |
| /// |
| /// @param[in] data |
| /// A data extractor configured to read and copy the DWARF |
| /// location expression's bytecode. |
| /// |
| /// @param[in] data_offset |
| /// The offset of the location expression in the extractor. |
| /// |
| /// @param[in] data_length |
| /// The byte length of the location expression. |
| //------------------------------------------------------------------ |
| void CopyOpcodeData(lldb::ModuleSP module_sp, const DataExtractor &data, |
| lldb::offset_t data_offset, lldb::offset_t data_length); |
| |
| void CopyOpcodeData(const void *data, lldb::offset_t data_length, |
| lldb::ByteOrder byte_order, uint8_t addr_byte_size); |
| |
| void CopyOpcodeData(uint64_t const_value, |
| lldb::offset_t const_value_byte_size, |
| uint8_t addr_byte_size); |
| |
| //------------------------------------------------------------------ |
| /// Tells the expression that it refers to a location list. |
| /// |
| /// @param[in] slide |
| /// This value should be a slide that is applied to any values |
| /// in the location list data so the values become zero based |
| /// offsets into the object that owns the location list. We need |
| /// to make location lists relative to the objects that own them |
| /// so we can relink addresses on the fly. |
| //------------------------------------------------------------------ |
| void SetLocationListSlide(lldb::addr_t slide); |
| |
| //------------------------------------------------------------------ |
| /// Return the call-frame-info style register kind |
| //------------------------------------------------------------------ |
| int GetRegisterKind(); |
| |
| //------------------------------------------------------------------ |
| /// Set the call-frame-info style register kind |
| /// |
| /// @param[in] reg_kind |
| /// The register kind. |
| //------------------------------------------------------------------ |
| void SetRegisterKind(lldb::RegisterKind reg_kind); |
| |
| //------------------------------------------------------------------ |
| /// Wrapper for the static evaluate function that accepts an |
| /// ExecutionContextScope instead of an ExecutionContext and uses member |
| /// variables to populate many operands |
| //------------------------------------------------------------------ |
| bool Evaluate(ExecutionContextScope *exe_scope, |
| lldb::addr_t loclist_base_load_addr, |
| const Value *initial_value_ptr, const Value *object_address_ptr, |
| Value &result, Status *error_ptr) const; |
| |
| //------------------------------------------------------------------ |
| /// Wrapper for the static evaluate function that uses member variables to |
| /// populate many operands |
| //------------------------------------------------------------------ |
| bool Evaluate(ExecutionContext *exe_ctx, RegisterContext *reg_ctx, |
| lldb::addr_t loclist_base_load_addr, |
| const Value *initial_value_ptr, const Value *object_address_ptr, |
| Value &result, Status *error_ptr) const; |
| |
| //------------------------------------------------------------------ |
| /// Evaluate a DWARF location expression in a particular context |
| /// |
| /// @param[in] exe_ctx |
| /// The execution context in which to evaluate the location |
| /// expression. The location expression may access the target's |
| /// memory, especially if it comes from the expression parser. |
| /// |
| /// @param[in] opcode_ctx |
| /// The module which defined the expression. |
| /// |
| /// @param[in] opcodes |
| /// This is a static method so the opcodes need to be provided |
| /// explicitly. |
| /// |
| /// @param[in] expr_locals |
| /// If the location expression was produced by the expression parser, |
| /// the list of local variables referenced by the DWARF expression. |
| /// This list should already have been populated during parsing; |
| /// the DWARF expression refers to variables by index. Can be NULL if |
| /// the location expression uses no locals. |
| /// |
| /// @param[in] decl_map |
| /// If the location expression was produced by the expression parser, |
| /// the list of external variables referenced by the location |
| /// expression. Can be NULL if the location expression uses no |
| /// external variables. |
| /// |
| /// @param[in] reg_ctx |
| /// An optional parameter which provides a RegisterContext for use |
| /// when evaluating the expression (i.e. for fetching register values). |
| /// Normally this will come from the ExecutionContext's StackFrame but |
| /// in the case where an expression needs to be evaluated while building |
| /// the stack frame list, this short-cut is available. |
| /// |
| /// @param[in] offset |
| /// The offset of the location expression in the data extractor. |
| /// |
| /// @param[in] length |
| /// The length in bytes of the location expression. |
| /// |
| /// @param[in] reg_set |
| /// The call-frame-info style register kind. |
| /// |
| /// @param[in] initial_value_ptr |
| /// A value to put on top of the interpreter stack before evaluating |
| /// the expression, if the expression is parametrized. Can be NULL. |
| /// |
| /// @param[in] result |
| /// A value into which the result of evaluating the expression is |
| /// to be placed. |
| /// |
| /// @param[in] error_ptr |
| /// If non-NULL, used to report errors in expression evaluation. |
| /// |
| /// @return |
| /// True on success; false otherwise. If error_ptr is non-NULL, |
| /// details of the failure are provided through it. |
| //------------------------------------------------------------------ |
| static bool Evaluate(ExecutionContext *exe_ctx, RegisterContext *reg_ctx, |
| lldb::ModuleSP opcode_ctx, const DataExtractor &opcodes, |
| DWARFUnit *dwarf_cu, const lldb::offset_t offset, |
| const lldb::offset_t length, |
| const lldb::RegisterKind reg_set, |
| const Value *initial_value_ptr, |
| const Value *object_address_ptr, Value &result, |
| Status *error_ptr); |
| |
| bool GetExpressionData(DataExtractor &data) const { |
| data = m_data; |
| return data.GetByteSize() > 0; |
| } |
| |
| bool DumpLocationForAddress(Stream *s, lldb::DescriptionLevel level, |
| lldb::addr_t loclist_base_load_addr, |
| lldb::addr_t address, ABI *abi); |
| |
| static size_t LocationListSize(const DWARFUnit *dwarf_cu, |
| const DataExtractor &debug_loc_data, |
| lldb::offset_t offset); |
| |
| static bool PrintDWARFExpression(Stream &s, const DataExtractor &data, |
| int address_size, int dwarf_ref_size, |
| bool location_expression); |
| |
| static void PrintDWARFLocationList(Stream &s, const DWARFUnit *cu, |
| const DataExtractor &debug_loc_data, |
| lldb::offset_t offset); |
| |
| bool MatchesOperand(StackFrame &frame, const Instruction::Operand &op); |
| |
| protected: |
| //------------------------------------------------------------------ |
| /// Pretty-prints the location expression to a stream |
| /// |
| /// @param[in] stream |
| /// The stream to use for pretty-printing. |
| /// |
| /// @param[in] offset |
| /// The offset into the data buffer of the opcodes to be printed. |
| /// |
| /// @param[in] length |
| /// The length in bytes of the opcodes to be printed. |
| /// |
| /// @param[in] level |
| /// The level of detail to use in pretty-printing. |
| /// |
| /// @param[in] abi |
| /// An optional ABI plug-in that can be used to resolve register |
| /// names. |
| //------------------------------------------------------------------ |
| void DumpLocation(Stream *s, lldb::offset_t offset, lldb::offset_t length, |
| lldb::DescriptionLevel level, ABI *abi) const; |
| |
| bool GetLocation(lldb::addr_t base_addr, lldb::addr_t pc, |
| lldb::offset_t &offset, lldb::offset_t &len); |
| |
| static bool AddressRangeForLocationListEntry( |
| const DWARFUnit *dwarf_cu, const DataExtractor &debug_loc_data, |
| lldb::offset_t *offset_ptr, lldb::addr_t &low_pc, lldb::addr_t &high_pc); |
| |
| bool GetOpAndEndOffsets(StackFrame &frame, lldb::offset_t &op_offset, |
| lldb::offset_t &end_offset); |
| |
| //------------------------------------------------------------------ |
| /// Classes that inherit from DWARFExpression can see and modify these |
| //------------------------------------------------------------------ |
| |
| lldb::ModuleWP m_module_wp; ///< Module which defined this expression. |
| DataExtractor m_data; ///< A data extractor capable of reading opcode bytes |
| DWARFUnit *m_dwarf_cu; ///< The DWARF compile unit this expression |
| ///belongs to. It is used |
| ///< to evaluate values indexing into the .debug_addr section (e.g. |
| ///< DW_OP_GNU_addr_index, DW_OP_GNU_const_index) |
| lldb::RegisterKind |
| m_reg_kind; ///< One of the defines that starts with LLDB_REGKIND_ |
| lldb::addr_t m_loclist_slide; ///< A value used to slide the location list |
| ///offsets so that |
| ///< they are relative to the object that owns the location list |
| ///< (the function for frame base and variable location lists) |
| }; |
| |
| } // namespace lldb_private |
| |
| #endif // liblldb_DWARFExpression_h_ |
