AsmJit Project
Machine Code Generation for C++
Contains basic information about the target architecture and its options.
In addition, it holds assembled code & data (including sections, labels, and relocation information). CodeHolder can store both binary and intermediate representation of assembly, which can be generated by BaseAssembler, BaseBuilder, and BaseCompiler
CodeHolder has an ability to attach an ErrorHandler, however, the error handler is not triggered by CodeHolder itself, it's instead propagated to all emitters that attach to it. Options that can be used with copySectionData() and copyFlattenedData().
| Constant | Description |
|---|---|
| kCopyPadSectionBuffer | If virtual size of a section is greater than the size of its CodeBuffer then all bytes between the buffer size and virtual size will be zeroed. If this option is not set then those bytes would be left as is, which means that if the user didn't initialize them they would have a previous content, which may be unwanted. |
| kCopyPadTargetBuffer | Zeroes the target buffer if the flattened data is less than the destination size. This option works only with copyFlattenedData() as it processes multiple sections. It is ignored by copySectionData(). |
Creates an uninitialized CodeHolder (you must init() it before it can be used).
Destroys the CodeHolder.
Tests whether the CodeHolder has been initialized.
Emitters can be only attached to initialized CodeHolder instances.
Globals::kNoBaseAddress)noexcept¶Initializes CodeHolder to hold code described by code info.
Globals::kResetSoft)noexcept¶Detaches all code-generators attached and resets the CodeHolder.
Attaches an emitter to this CodeHolder.
Detaches an emitter from this CodeHolder.
Returns the allocator that the CodeHolder uses.
Returns the target environment information, see Environment.
Returns the target architecture.
Returns the target sub-architecture.
Tests whether a static base-address is set.
Returns a static base-address or Globals::kNoBaseAddress, if not set.
Returns a vector of attached emitters.
Returns the attached logger, see Logger.
Attaches a logger to CodeHolder and propagates it to all attached emitters.
Resets the logger to none.
Tests whether the CodeHolder has an attached error handler, see ErrorHandler.
Returns the attached error handler.
Attach an error handler to this CodeHolder.
Resets the error handler to none.
Makes sure that at least n bytes can be added to CodeHolder's buffer cb.
cb must be managed by CodeHolder - otherwise the behavior of the function is undefined. Reserves the size of cb to at least n bytes.
cb must be managed by CodeHolder - otherwise the behavior of the function is undefined. Returns an array of Section* records.
Returns the number of sections.
Tests whether the given sectionId is valid.
SIZE_MAX, uint32_t flags = 0, uint32_t alignment = 1)noexcept¶Creates a new section and return its pointer in sectionOut.
Returns Error, does not report a possible error to ErrorHandler.
Returns a section entry of the given index.
SIZE_MAX) constnoexcept¶Returns section-id that matches the given name.
If there is no such section Section::kInvalidId is returned.
Returns '.text' section (section that commonly represents code).
Tests whether '.addrtab' section exists.
Returns '.addrtab' section.
This section is used exclusively by AsmJit to store absolute 64-bit addresses that cannot be encoded in instructions like 'jmp' or 'call'.
Ensures that '.addrtab' section exists (creates it if it doesn't) and returns it.
Can return nullptr on out of memory condition.
Used to add an address to an address table.
This implicitly calls ensureAddressTableSection() and then creates AddressTableEntry that is inserted to _addressTableEntries. If the address already exists this operation does nothing as the same addresses use the same slot.
This function should be considered internal as it's used by assemblers to insert an absolute address into the address table. Inserting address into address table without creating a particula relocation entry makes no sense.
Returns array of LabelEntry* records.
Returns number of labels created.
Tests whether the label having id is valid (i.e. created by newLabelEntry()).
Tests whether the label is valid (i.e. created by newLabelEntry()).
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
Tests whether the label is already bound.
Returns false if the label is not valid.
Returns LabelEntry of the given label id.
Returns LabelEntry of the given label.
Returns offset of a Label by its labelId.
The offset returned is relative to the start of the section. Zero offset is returned for unbound labels, which is their initial offset value.
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
Returns offset of a label by it's labelId relative to the base offset.
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
Creates a new anonymous label and return its id in idOut.
Returns Error, does not report error to ErrorHandler.
Globals::kInvalidId)noexcept¶Creates a new named LabelEntry of the given label type.
| entryOut | Where to store the created LabelEntry. |
| name | The name of the label. |
| nameSize | The length of name argument, or SIZE_MAX if name is a null terminated string, which means that the CodeHolder will use strlen() to determine the length. |
| type | The type of the label to create, see Label::LabelType. |
| parentId | Parent id of a local label, otherwise it must be Globals::kInvalidId. |
| Always | returns Error, does not report a possible error to the attached ErrorHandler. |
AsmJit has a support for local labels (Label::kTypeLocal) which require a parent label id (parentId). The names of local labels can conflict with names of other local labels that have a different parent.
SIZE_MAX, uint32_t parentId = Globals::kInvalidId)noexcept¶Returns a label by name.
If the named label doesn't a default constructed Label is returned, which has its id set to Globals::kInvalidId.
SIZE_MAX, uint32_t parentId = Globals::kInvalidId)noexcept¶Returns a label id by name.
If the named label doesn't exist Globals::kInvalidId is returned.
Tests whether there are any unresolved label links.
Returns the number of label links, which are unresolved.
Creates a new label-link used to store information about yet unbound labels.
Returns null if the allocation failed.
Resolves cross-section links (LabelLink) associated with each label that was used as a destination in code of a different section.
It's only useful to people that use multiple sections as it will do nothing if the code only contains a single section in which cross-section links are not possible.
Binds a label to a given sectionId and offset (relative to start of the section).
This function is generally used by BaseAssembler::bind() to do the heavy lifting.
Tests whether the code contains relocation entries.
Returns array of RelocEntry* records.
Returns a RelocEntry of the given id.
Creates a new relocation entry of type relocType and size valueSize.
Additional fields can be set after the relocation entry was created.
Flattens all sections by recalculating their offsets, starting at 0.
Returns computed the size of code & data of all sections.
flatten() and relocateToBase(). Relocates the code to the given baseAddress.
| baseAddress | Absolute base address where the code will be relocated to. Please note that nothing is copied to such base address, it's just an absolute value used by the relocator to resolve all stored relocations. |
0)noexcept¶Copies a single section into dst.
0)noexcept¶Copies all sections into dst.
This should only be used if the data was flattened and there are no gaps between the sections. The dstSize is always checked and the copy will never write anything outside the provided buffer.
Environment information.
Base address or Globals::kNoBaseAddress.
Attached Logger, used by all consumers.
Attached ErrorHandler.
Code zone (used to allocate core structures).
Zone allocator, used to manage internal containers.
Attached emitters.
Section entries.
Label entries.
Relocation entries.
Label name -> LabelEntry (only named labels).
Count of label links, which are not resolved.
Pointer to an address table section (or null if this section doesn't exist).
Address table entries.