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llvm / llvm-project / a259686db1c5f3f9904f266cbb084a8baeaf86d7 / . / lldb / include / lldb / Symbol / ObjectFile.h
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//===-- ObjectFile.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_ObjectFile_h_
#define liblldb_ObjectFile_h_
#include "lldb/lldb-private.h"
#include "lldb/Core/DataExtractor.h"
#include "lldb/Host/FileSpec.h"
#include "lldb/Core/ModuleChild.h"
#include "lldb/Core/PluginInterface.h"
#include "lldb/Host/Endian.h"
#include "lldb/Symbol/Symtab.h"
#include "lldb/Symbol/UnwindTable.h"
namespace lldb_private {
//----------------------------------------------------------------------
/// @class ObjectFile ObjectFile.h "lldb/Symbol/ObjectFile.h"
/// @brief A plug-in interface definition class for object file parsers.
///
/// Object files belong to Module objects and know how to extract
/// information from executable, shared library, and object (.o) files
/// used by operating system runtime. The symbol table and section list
/// for an object file.
///
/// Object files can be represented by the entire file, or by part of a
/// file. Examples of object files that are part of a file include
/// object files that contain information for multiple architectures in
/// the same file, or archive files that contain multiple objects
/// (ranlib archives) (possibly for multiple architectures as well).
///
/// Object archive files (e.g. ranlib archives) can contain
/// multiple .o (object) files that must be selected by index or by name.
/// The number of objects that an ObjectFile contains can be determined
/// using the ObjectFile::GetNumObjects() const
/// function, and followed by a call to
/// ObjectFile::SelectObjectAtIndex (uint32_t) to change the currently
/// selected object. Objects can also be selected by name using the
/// ObjectFile::SelectObject(const char *) function.
///
/// Once an architecture is selected (and an object is selected for
/// for archives), the object file information can be extracted from
/// this abstract class.
//----------------------------------------------------------------------
class ObjectFile:
public PluginInterface,
public ModuleChild
{
friend class lldb_private::Module;
public:
//------------------------------------------------------------------
/// Construct with a parent module, offset, and header data.
///
/// Object files belong to modules and a valid module must be
/// supplied upon construction. The at an offset within a file for
/// objects that contain more than one architecture or object.
//------------------------------------------------------------------
ObjectFile (Module* module, const FileSpec *file_spec_ptr, lldb::addr_t offset, lldb::addr_t length, lldb::DataBufferSP& headerDataSP) :
ModuleChild (module),
m_file (), // This file could be different from the original module's file
m_offset (offset),
m_length (length),
m_data (headerDataSP, lldb::endian::InlHostByteOrder(), 4),
m_unwind_table (*this)
{
if (file_spec_ptr)
m_file = *file_spec_ptr;
}
//------------------------------------------------------------------
/// Destructor.
///
/// The destructor is virtual since this class is designed to be
/// inherited from by the plug-in instance.
//------------------------------------------------------------------
virtual
~ObjectFile()
{
}
//------------------------------------------------------------------
/// Dump a description of this object to a Stream.
///
/// Dump a description of the current contents of this object
/// to the supplied stream \a s. The dumping should include the
/// section list if it has been parsed, and the symbol table
/// if it has been parsed.
///
/// @param[in] s
/// The stream to which to dump the object descripton.
//------------------------------------------------------------------
virtual void
Dump (Stream *s) = 0;
//------------------------------------------------------------------
/// Find a ObjectFile plug-in that can parse \a file_spec.
///
/// Scans all loaded plug-in interfaces that implement versions of
/// the ObjectFile plug-in interface and returns the first
/// instance that can parse the file.
///
/// @param[in] module
/// The parent module that owns this object file.
///
/// @param[in] file_spec
/// A file specification that indicates which file to use as the
/// object file.
///
/// @param[in] file_offset
/// The offset into the file at which to start parsing the
/// object. This is for files that contain multiple
/// architectures or objects.
///
/// @param[in] file_size
/// The size of the current object file if it can be determined
/// or if it is known. This can be zero.
///
/// @see ObjectFile::ParseHeader()
//------------------------------------------------------------------
static ObjectFile*
FindPlugin (Module* module,
const FileSpec* file_spec,
lldb::addr_t file_offset,
lldb::addr_t file_size);
//------------------------------------------------------------------
/// Gets the address size in bytes for the current object file.
///
/// @return
/// The size of an address in bytes for the currently selected
/// architecture (and object for archives). Returns zero if no
/// architecture or object has been selected.
//------------------------------------------------------------------
virtual size_t
GetAddressByteSize () const = 0;
//------------------------------------------------------------------
/// Extract the dependent modules from an object file.
///
/// If an object file has information about which other images it
/// depends on (such as shared libraries), this function will
/// provide the list. Since many executables or shared libraries
/// may depend on the same files,
/// FileSpecList::AppendIfUnique(const FileSpec &) should be
/// used to make sure any files that are added are not already in
/// the list.
///
/// @param[out] file_list
/// A list of file specification objects that gets dependent
/// files appended to.
///
/// @return
/// The number of new files that were appended to \a file_list.
///
/// @see FileSpecList::AppendIfUnique(const FileSpec &)
//------------------------------------------------------------------
virtual uint32_t
GetDependentModules (FileSpecList& file_list) = 0;
//------------------------------------------------------------------
/// Tells whether this object file is capable of being the main executable
/// for a process.
///
/// @return
/// \b true if it is, \b false otherwise.
//------------------------------------------------------------------
virtual bool
IsExecutable () const = 0;
//------------------------------------------------------------------
/// Returns the offset into a file at which this object resides.
///
/// Some files contain many object files, and this function allows
/// access to an object's offset within the file.
///
/// @return
/// The offset in bytes into the file. Defaults to zero for
/// simple object files that a represented by an entire file.
//------------------------------------------------------------------
virtual lldb::addr_t
GetOffset () const
{ return m_offset; }
virtual lldb::addr_t
GetByteSize () const
{ return m_length; }
//------------------------------------------------------------------
/// Get accessor to the object file specification.
///
/// @return
/// The file specification object pointer if there is one, or
/// NULL if this object is only from memory.
//------------------------------------------------------------------
virtual FileSpec&
GetFileSpec() { return m_file; }
//------------------------------------------------------------------
/// Get const accessor to the object file specification.
///
/// @return
/// The const file specification object pointer if there is one,
/// or NULL if this object is only from memory.
//------------------------------------------------------------------
virtual const FileSpec&
GetFileSpec() const { return m_file; }
//------------------------------------------------------------------
/// Get the name of the cpu, vendor and OS for this object file.
///
/// This value is a string that represents the target triple where
/// the cpu type, the vendor and the OS are encoded into a string.
///
/// @param[out] target_triple
/// The string value of the target triple.
///
/// @return
/// \b True if the target triple was able to be computed, \b
/// false otherwise.
//------------------------------------------------------------------
virtual bool
GetArchitecture (ArchSpec &arch) = 0;
//------------------------------------------------------------------
/// Gets the section list for the currently selected architecture
/// (and object for archives).
///
/// Section list parsing can be deferred by ObjectFile instances
/// until this accessor is called the first time.
///
/// @return
/// The list of sections contained in this object file.
//------------------------------------------------------------------
virtual SectionList *
GetSectionList () = 0;
//------------------------------------------------------------------
/// Gets the symbol table for the currently selected architecture
/// (and object for archives).
///
/// Symbol table parsing can be deferred by ObjectFile instances
/// until this accessor is called the first time.
///
/// @return
/// The symbol table for this object file.
//------------------------------------------------------------------
virtual Symtab *
GetSymtab () = 0;
//------------------------------------------------------------------
/// Gets the UUID for this object file.
///
/// If the object file format contains a UUID, the value should be
/// returned. Else ObjectFile instances should return the MD5
/// checksum of all of the bytes for the object file (or memory for
/// memory based object files).
///
/// @return
/// Returns \b true if a UUID was successfully extracted into
/// \a uuid, \b false otherwise.
//------------------------------------------------------------------
virtual bool
GetUUID (lldb_private::UUID* uuid) = 0;
//------------------------------------------------------------------
/// Gets whether endian swapping should occur when extracting data
/// from this object file.
///
/// @return
/// Returns \b true if endian swapping is needed, \b false
/// otherwise.
//------------------------------------------------------------------
virtual lldb::ByteOrder
GetByteOrder () const = 0;
//------------------------------------------------------------------
/// Attempts to parse the object header.
///
/// This function is used as a test to see if a given plug-in
/// instance can parse the header data already contained in
/// ObjectFile::m_data. If an object file parser does not
/// recognize that magic bytes in a header, false should be returned
/// and the next plug-in can attempt to parse an object file.
///
/// @return
/// Returns \b true if the header was parsed succesfully, \b
/// false otherwise.
//------------------------------------------------------------------
virtual bool
ParseHeader () = 0;
//------------------------------------------------------------------
/// Returns a reference to the UnwindTable for this ObjectFile
///
/// The UnwindTable contains FuncUnwinders objects for any function in
/// this ObjectFile. If a FuncUnwinders object hasn't been created yet
/// (i.e. the function has yet to be unwound in a stack walk), it
/// will be created when requested. Specifically, we do not create
/// FuncUnwinders objects for functions until they are needed.
///
/// @return
/// Returns the unwind table for this object file.
//------------------------------------------------------------------
virtual lldb_private::UnwindTable&
GetUnwindTable () { return m_unwind_table; }
//------------------------------------------------------------------
/// Similar to Process::GetImageInfoAddress().
///
/// Some platforms embed auxiliary structures useful to debuggers in the
/// address space of the inferior process. This method returns the address
/// of such a structure if the information can be resolved via entries in
/// the object file. ELF, for example, provides a means to hook into the
/// runtime linker so that a debugger may monitor the loading and unloading
/// of shared libraries.
///
/// @return
/// The address of any auxiliary tables, or an invalid address if this
/// object file format does not support or contain such information.
virtual lldb_private::Address
GetImageInfoAddress () { return Address(); }
//------------------------------------------------------------------
/// Returns the address of the Entry Point in this object file - if
/// the object file doesn't have an entry point (because it is not an
/// executable file) then an invalid address is returned.
///
/// @return
/// Returns the entry address for this module.
//------------------------------------------------------------------
virtual lldb_private::Address
GetEntryPointAddress () { return Address();}
protected:
//------------------------------------------------------------------
// Member variables.
//------------------------------------------------------------------
FileSpec m_file;
lldb::addr_t m_offset; ///< The offset in bytes into the file, or the address in memory
lldb::addr_t m_length; ///< The length of this object file if it is known (can be zero if length is unknown or can't be determined).
DataExtractor m_data; ///< The data for this object file so things can be parsed lazily.
lldb_private::UnwindTable m_unwind_table; /// < Table of FuncUnwinders objects created for this ObjectFile's functions
//------------------------------------------------------------------
/// Sets the architecture for a module. At present the architecture
/// can only be set if it is invalid. It is not allowed to switch from
/// one concrete architecture to another.
///
/// @param[in] new_arch
/// The architecture this module will be set to.
///
/// @return
/// Returns \b true if the architecture was changed, \b
/// false otherwise.
//------------------------------------------------------------------
bool SetModulesArchitecture (const ArchSpec &new_arch);
private:
DISALLOW_COPY_AND_ASSIGN (ObjectFile);
};
} // namespace lldb_private
#endif // liblldb_ObjectFile_h_