com.oracle.objectfile

Class BasicProgbitsSectionImpl

java.lang.Object

com.oracle.objectfile.BasicElementImpl

com.oracle.objectfile.BasicProgbitsSectionImpl

All Implemented Interfaces:

ElementImpl, ObjectFile.ProgbitsSectionImpl, ObjectFile.RelocatableSectionImpl

public class BasicProgbitsSectionImpl
extends BasicElementImpl
implements ObjectFile.ProgbitsSectionImpl

This represents the core of a progbits/regular section, in any object file format. By default it delegates to an underlying Section object, of some format-specific class.

Constructor Summary

Constructors

Constructor and Description
BasicProgbitsSectionImpl() Create a new BasicProgbitsSectionImpl not associated with a section.
BasicProgbitsSectionImpl(byte[] content)
BasicProgbitsSectionImpl(byte[] content, ObjectFile.Section s)
BasicProgbitsSectionImpl(ObjectFile.Section s)

Method Summary

Modifier and Type	Method and Description
int	getAlignment()
byte[]	getContent()
Set<BuildDependency>	getDependencies(Map<ObjectFile.Element,LayoutDecisionMap> decisions) Implementing this method allows to declare dependencies to other Sections (i.e.
ObjectFile.Section	getElement()
List<ObjectFile.Section>	getElements()
int	getMemSize(Map<ObjectFile.Element,LayoutDecisionMap> alreadyDecided) Implement this method to provide the section size in memory (at runtime).
ObjectFile.Element	getOrCreateRelocationElement(boolean useImplicitAddend) Force the creation of a relocation section/element for this section, and return it.
byte[]	getOrDecideContent(Map<ObjectFile.Element,LayoutDecisionMap> alreadyDecided, byte[] contentHint) Implement this method to deliver the content of the section.
int	getOrDecideSize(Map<ObjectFile.Element,LayoutDecisionMap> alreadyDecided, int sizeHint) Implement this method to provide the size of this section.
boolean	isLoadable() Whether this section is loaded into memory at runtime.
ObjectFile.RelocationRecord	markRelocationSite(int offset, int length, ByteBuffer bb, ObjectFile.RelocationKind k, String symbolName, boolean useImplicitAddend, Long explicitAddend) Record (in a format-specific way) that data at the given offset in the file, for the given number of bytes, should be fixed up according to the value of the given symbol and the given kind of relocation.
ObjectFile.RelocationRecord	markRelocationSite(int offset, int length, ObjectFile.RelocationKind k, String symbolName, boolean useImplicitAddend, Long explicitAddend) This is like ObjectFile.RelocatableSectionImpl.markRelocationSite(int, int, java.nio.ByteBuffer, com.oracle.objectfile.ObjectFile.RelocationKind, java.lang.String, boolean, java.lang.Long), but doesn't need to be passed a buffer.
void	setContent(byte[] c)

Methods inherited from class com.oracle.objectfile.BasicElementImpl

getDecisions, getOrDecideOffset, getOrDecideVaddr, getOwner, isReferenceable, setElement

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.oracle.objectfile.ElementImpl

getDecisions, getOrDecideOffset, getOrDecideVaddr, isReferenceable, setElement

Constructor Detail

BasicProgbitsSectionImpl

public BasicProgbitsSectionImpl(byte[] content)

BasicProgbitsSectionImpl

public BasicProgbitsSectionImpl(ObjectFile.Section s)

BasicProgbitsSectionImpl

public BasicProgbitsSectionImpl(byte[] content,
                                ObjectFile.Section s)

BasicProgbitsSectionImpl

public BasicProgbitsSectionImpl()

Create a new BasicProgbitsSectionImpl not associated with a section. The caller must arrange that setElement is called, after constructing a section which references this -Impl.

Method Detail

getDependencies

public Set<BuildDependency> getDependencies(Map<ObjectFile.Element,LayoutDecisionMap> decisions)

Description copied from interface: ElementImpl

Implementing this method allows to declare dependencies to other Sections (i.e. information about other sections needed to construct this section). The information will be used to construct the buildOrder in ObjectFile.writeInternal(). A good example can be found at: ELFObjectFile.ProgramHeaderTable.getDependencies

Specified by:

getDependencies in interface ElementImpl

Overrides:

getDependencies in class BasicElementImpl

getOrDecideSize

public int getOrDecideSize(Map<ObjectFile.Element,LayoutDecisionMap> alreadyDecided,
                           int sizeHint)

Description copied from interface: ElementImpl

Implement this method to provide the size of this section.

Specified by:

getOrDecideSize in interface ElementImpl

Overrides:

getOrDecideSize in class BasicElementImpl

getOrDecideContent

public byte[] getOrDecideContent(Map<ObjectFile.Element,LayoutDecisionMap> alreadyDecided,
                                 byte[] contentHint)

Description copied from interface: ElementImpl

Implement this method to deliver the content of the section.

Specified by:

getOrDecideContent in interface ElementImpl

getMemSize

public int getMemSize(Map<ObjectFile.Element,LayoutDecisionMap> alreadyDecided)

Description copied from interface: ElementImpl

Implement this method to provide the section size in memory (at runtime).

Specified by:

getMemSize in interface ElementImpl

Overrides:

getMemSize in class BasicElementImpl

getAlignment

public int getAlignment()

Specified by:

getAlignment in interface ElementImpl

Overrides:

getAlignment in class BasicElementImpl

setContent

public void setContent(byte[] c)

Specified by:

setContent in interface ObjectFile.ProgbitsSectionImpl

getContent

public byte[] getContent()

Specified by:

getContent in interface ObjectFile.ProgbitsSectionImpl

getElement

public ObjectFile.Section getElement()

Specified by:

getElement in interface ElementImpl

Overrides:

getElement in class BasicElementImpl

getElements

public List<ObjectFile.Section> getElements()

markRelocationSite

public ObjectFile.RelocationRecord markRelocationSite(int offset,
                                                      int length,
                                                      ObjectFile.RelocationKind k,
                                                      String symbolName,
                                                      boolean useImplicitAddend,
                                                      Long explicitAddend)

Description copied from interface: ObjectFile.ProgbitsSectionImpl

This is like ObjectFile.RelocatableSectionImpl.markRelocationSite(int, int, java.nio.ByteBuffer, com.oracle.objectfile.ObjectFile.RelocationKind, java.lang.String, boolean, java.lang.Long), but doesn't need to be passed a buffer. It uses the byte array accessed by ObjectFile.ProgbitsSectionImpl.getContent() and ObjectFile.ProgbitsSectionImpl.setContent(byte[]).

Specified by:

markRelocationSite in interface ObjectFile.ProgbitsSectionImpl

markRelocationSite

public final ObjectFile.RelocationRecord markRelocationSite(int offset,
                                                            int length,
                                                            ByteBuffer bb,
                                                            ObjectFile.RelocationKind k,
                                                            String symbolName,
                                                            boolean useImplicitAddend,
                                                            Long explicitAddend)

Description copied from interface: ObjectFile.RelocatableSectionImpl

Record (in a format-specific way) that data at the given offset in the file, for the given number of bytes, should be fixed up according to the value of the given symbol and the given kind of relocation. Depending on the object file format, kind of file, and target architecture, the available kinds of relocation and addend modes all vary considerably. Supporting a uniform interface is therefore complicated. In particular, the implementation of these methods somehow has to tell the caller how to fix up the section content, or fix it up itself. For example, ELF uses explicit addends for dynamic linking on x86-64, but Mach-O in the same case always uses implicit (inline) addends and cannot encode explicit addends. I can see two solutions. Firstly, the Mach-O implementation could come back to the caller saying "here is what you need to add to the current section contents". Or secondly, the section implementation could take care of it somehow, but that assumes it has access to the actual contents s.t. any changes will not later be clobbered. TODO: CHECK whether this is true of our native native image code.

Specified by:

markRelocationSite in interface ObjectFile.RelocatableSectionImpl

Parameters:

offset - the offset into the section contents of the beginning of the fixed-up bytes

length - the length of byte sequence to be fixed up

bb - the byte buffer representing the encoded section contents, at least as far as offset + length bytes

k - the kind of fixup to be applied

symbolName - the name of the symbol whose value is used to compute the fixed-up bytes

useImplicitAddend - whether the current bytes are to be used as an addend

explicitAddend - a full-width addend, or null if useImplicitAddend is true

Returns:

the relocation record created (or found, if it exists already)

getOrCreateRelocationElement

public ObjectFile.Element getOrCreateRelocationElement(boolean useImplicitAddend)

Description copied from interface: ObjectFile.RelocatableSectionImpl

Force the creation of a relocation section/element for this section, and return it. This is necessary to avoid the on-demand instantiation of relocation sections at write()-time, which leads to unpredictable results (e.g. not appearing in the ELF SHT, if the SHT was written before the section was created).

Specified by:

getOrCreateRelocationElement in interface ObjectFile.RelocatableSectionImpl

Parameters:

useImplicitAddend - whether the relocation section of interest is for implicit addends

Returns:

the element which will hold relocation records (of the argument-specified kind) for this section

isLoadable

public boolean isLoadable()

Description copied from interface: ElementImpl

Whether this section is loaded into memory at runtime.

Specified by:

isLoadable in interface ElementImpl