Package net.fornwall.jelf

Class ElfSymbol

java.lang.Object
net.fornwall.jelf.ElfSymbol
public final class ElfSymbol extends Object
An entry in the ElfSymbolTableSection, which holds information needed to locate and relocate a program's symbolic definitions and references.

In the elf.h header file the struct definitions are: 

 typedef struct {
     uint32_t      st_name;
     Elf32_Addr    st_value;
     uint32_t      st_size;
     unsigned char st_info;
     unsigned char st_other;
     uint16_t      st_shndx;
 } Elf32_Sym;

 typedef struct {
     uint32_t      st_name;
     unsigned char st_info;
     unsigned char st_other;
     uint16_t      st_shndx;
     Elf64_Addr    st_value;
     uint64_t      st_size;
 } Elf64_Sym;

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    BINDING_GLOBAL
    Binding specifying that global symbols are visible to all object files being combined.
    static final int
    BINDING_HIPROC
    Upper bound binding values reserved for processor specific semantics.
    static final int
    BINDING_LOCAL
    Binding specifying that local symbols are not visible outside the object file that contains its definition.
    static final int
    BINDING_LOPROC
    Lower bound binding values reserved for processor specific semantics.
    static final int
    BINDING_WEAK
    Binding specifying that the symbol resembles a global symbol, but has a lower precedence.
    final long
    offset
    Offset from the beginning of the file to this symbol.
    final int
    section_type
     
    final short
    st_info
    Specifies the symbol type and binding attributes.
    final int
    st_name
    Index into the symbol string table that holds the character representation of the symbols.
    final short
    st_other
    Currently holds the value of 0 and has no meaning.
    final short
    st_shndx
    Index to the associated section header.
    final long
    st_size
    Size of the symbol.
    final long
    st_value
    Value of the associated symbol.
    static final byte
    STT_COMMON
    The symbol labels an uninitialized common block.
    static final byte
    STT_FILE
    Type defining that the symbol is associated with a file.
    static final byte
    STT_FUNC
    Type specifying that the symbol is associated with a function or other executable code.
    static final byte
    STT_HIOS
    Upper bound for range reserved for operating system-specific semantics.
    static final byte
    STT_HIPROC
    Upper bound for range reserved for processor-specific semantics.
    static final byte
    STT_LOOS
    Lower bound for range reserved for operating system-specific semantics.
    static final byte
    STT_LOPROC
    Lower bound for range reserved for processor-specific semantics.
    static final byte
    STT_NOTYPE
    Type specifying that the symbol is unspecified.
    static final byte
    STT_OBJECT
    Type specifying that the symbol is associated with an object.
    static final byte
    STT_SECTION
    Type specifying that the symbol is associated with a section.
    static final byte
    STT_TLS
    The symbol specifies a Thread-Local Storage entity.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    getBinding()
    Returns the binding for this symbol, extracted from the st_info field.
    String
    getName()
    Returns the name of the symbol or null if the symbol has no name.
    int
    getType()
    Returns the symbol type, extracted from the st_info field.
    net.fornwall.jelf.ElfSymbol.Visibility
    getVisibility()
     
    String
    toString()
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

    • BINDING_LOCAL

      public static final int BINDING_LOCAL
      Binding specifying that local symbols are not visible outside the object file that contains its definition.
      See Also:

    • BINDING_GLOBAL

      public static final int BINDING_GLOBAL
      Binding specifying that global symbols are visible to all object files being combined.
      See Also:

    • BINDING_WEAK

      public static final int BINDING_WEAK
      Binding specifying that the symbol resembles a global symbol, but has a lower precedence.
      See Also:

    • BINDING_LOPROC

      public static final int BINDING_LOPROC
      Lower bound binding values reserved for processor specific semantics.
      See Also:

    • BINDING_HIPROC

      public static final int BINDING_HIPROC
      Upper bound binding values reserved for processor specific semantics.
      See Also:

    • STT_NOTYPE

      public static final byte STT_NOTYPE
      Type specifying that the symbol is unspecified.
      See Also:

    • STT_OBJECT

      public static final byte STT_OBJECT
      Type specifying that the symbol is associated with an object.
      See Also:

    • STT_FUNC

      public static final byte STT_FUNC
      Type specifying that the symbol is associated with a function or other executable code.
      See Also:

    • STT_SECTION

      public static final byte STT_SECTION
      Type specifying that the symbol is associated with a section. Symbol table entries of this type exist for relocation and normally have the binding BINDING_LOCAL.
      See Also:

    • STT_FILE

      public static final byte STT_FILE
      Type defining that the symbol is associated with a file.
      See Also:

    • STT_COMMON

      public static final byte STT_COMMON
      The symbol labels an uninitialized common block.
      See Also:

    • STT_TLS

      public static final byte STT_TLS
      The symbol specifies a Thread-Local Storage entity.
      See Also:

    • STT_LOOS

      public static final byte STT_LOOS
      Lower bound for range reserved for operating system-specific semantics.
      See Also:

    • STT_HIOS

      public static final byte STT_HIOS
      Upper bound for range reserved for operating system-specific semantics.
      See Also:

    • STT_LOPROC

      public static final byte STT_LOPROC
      Lower bound for range reserved for processor-specific semantics.
      See Also:

    • STT_HIPROC

      public static final byte STT_HIPROC
      Upper bound for range reserved for processor-specific semantics.
      See Also:

    • st_name

      public final int st_name
      Index into the symbol string table that holds the character representation of the symbols. 0 means the symbol has no character name.

    • st_value

      public final long st_value
      Value of the associated symbol. This may be a relative address for .so or absolute address for other ELFs.

    • st_size

      public final long st_size
      Size of the symbol. 0 if the symbol has no size or the size is unknown.

    • st_info

      public final short st_info
      Specifies the symbol type and binding attributes.

    • st_other

      public final short st_other
      Currently holds the value of 0 and has no meaning.

    • st_shndx

      public final short st_shndx
      Index to the associated section header. This value will need to be read as an unsigned short if we compare it to ELFSectionHeader.NDX_LORESERVE and ELFSectionHeader.NDX_HIRESERVE.

    • section_type

      public final int section_type

    • offset

      public final long offset
      Offset from the beginning of the file to this symbol.

  • Method Details

    • getBinding

      public int getBinding()
      Returns the binding for this symbol, extracted from the st_info field.
      Returns:
      the binding for this symbol

    • getType

      public int getType()
      Returns the symbol type, extracted from the st_info field.
      Returns:
      the type of this symbol

    • getName

      public String getName() throws ElfException
      Returns the name of the symbol or null if the symbol has no name.
      Returns:
      the name of this symbol, if any
      Throws:
      ElfException

    • getVisibility

      public net.fornwall.jelf.ElfSymbol.Visibility getVisibility()

    • toString

      public String toString()
      Overrides:
      toString in class Object