Class ClassReader

🏭 Constructors

constructor public

ClassReader(buffer: Uint8Array, classFileOffset: number= 0, len: number= buffer.length): ClassReader

Constructs a new ClassReader object.

Parameters

• buffer: Uint8Array
• classFileOffset: number
• len: number the length of the class data.

Return Type

• ClassReader

Defined in: packages/asm/libs/ClassReader.ts:165

🏷️ Properties

buf public

buf: Uint8Array

The class to be parsed. <i>The content of this array must not be modified. This field is intended for Attribute sub classes, and is normally not needed by class generators or adapters.</i>

Defined in: packages/asm/libs/ClassReader.ts:128

header public

header: number

Start index of the class header information (access, name...) in [#b b].

Defined in: packages/asm/libs/ClassReader.ts:156

EXPAND_ASM_INSNS static

EXPAND_ASM_INSNS: number = 256

Flag to expand the ASM pseudo instructions into an equivalent sequence of standard bytecode instructions. When resolving a forward jump it may happen that the signed 2 bytes offset reserved for it is not sufficient to store the bytecode offset. In this case the jump instruction is replaced with a temporary ASM pseudo instruction using an unsigned 2 bytes offset (see Label#resolve). This internal flag is used to re-read classes containing such instructions, in order to replace them with standard instructions. In addition, when this flag is used, GOTO_W and JSR_W are <i>not</i> converted into GOTO and JSR, to make sure that infinite loops where a GOTO_W is replaced with a GOTO in ClassReader and converted back to a GOTO_W in ClassWriter cannot occur.

Defined in: packages/asm/libs/ClassReader.ts:121

EXPAND_FRAMES static public

EXPAND_FRAMES: number = 8

Flag to expand the stack map frames. By default stack map frames are visited in their original format (i.e. "expanded" for classes whose version is less than V1_6, and "compressed" for the other classes). If this flag is set, stack map frames are always visited in expanded format (this option adds a decompression/recompression step in ClassReader and ClassWriter which degrades performances quite a lot).

Defined in: packages/asm/libs/ClassReader.ts:106

RESIZE static

RESIZE: boolean = true

True to enable JSR_W and GOTO_W support.

Defined in: packages/asm/libs/ClassReader.ts:70

SKIP_CODE static public

SKIP_CODE: number = 1

Flag to skip method code. If this class is set <code>CODE</code> attribute won't be visited. This can be used, for example, to retrieve annotations for methods and method parameters.

Defined in: packages/asm/libs/ClassReader.ts:77

SKIP_DEBUG static public

SKIP_DEBUG: number = 2

Flag to skip the debug information in the class. If this flag is set the debug information of the class is not visited, i.e. the visitLocalVariable and visitLineNumber methods will not be called.

Defined in: packages/asm/libs/ClassReader.ts:86

SKIP_FRAMES static public

SKIP_FRAMES: number = 4

Flag to skip the stack map frames in the class. If this flag is set the stack map frames of the class is not visited, i.e. the visitFrame method will not be called. This flag is useful when the [ClassWriter#COMPUTE_FRAMES] option is used: it avoids visiting frames that will be ignored and recomputed from scratch in the class writer.

Defined in: packages/asm/libs/ClassReader.ts:96

WRITER static

WRITER: boolean = true

True to enable bytecode writing support.

Defined in: packages/asm/libs/ClassReader.ts:65

🔧 Methods

accept public

accept(classVisitor: ClassVisitor, attrs: Attribute[]= [], flags: number= 0): void

Makes the given visitor visit the Java class of this ClassReader. This class is the one specified in the constructor (see [#ClassReader(byte[]) ClassReader]).

Parameters

• classVisitor: ClassVisitor the visitor that must visit this class.
• attrs: Attribute[] prototypes of the attributes that must be parsed during the visit of the class. Any attribute whose type is not equal to the type of one the prototypes will not be parsed: its byte array value will be passed unchanged to the ClassWriterConstant. <i>This may corrupt it if this value contains references to the constant pool, or has syntactic or semantic links with a class element that has been transformed by a class adapter between the reader and the writer</i>.
• flags: number option flags that can be used to modify the default behavior of this class. See [#SKIP_DEBUG], [#EXPAND_FRAMES] , [#SKIP_FRAMES], [#SKIP_CODE].

Return Type

• void

Defined in: packages/asm/libs/ClassReader.ts:288

getAccess public

getAccess(): number

Returns the class's access flags (see Opcodes). This value may not reflect Deprecated and Synthetic flags when bytecode is before 1.5 and those flags are represented by attributes.

Return Type

• number

Defined in: packages/asm/libs/ClassReader.ts:220

getClassName public

getClassName(): string

Returns the internal name of the class (see [Type#getInternalName() getInternalName]).

Return Type

• string

Defined in: packages/asm/libs/ClassReader.ts:231

getInterfaces public

getInterfaces(): string[]

Returns the internal names of the class's interfaces (see [Type#getInternalName() getInternalName]).

Return Type

• string[]

Defined in: packages/asm/libs/ClassReader.ts:256

getItem public

getItem(item: number): number

Returns the start index of the constant pool item in [#b b], plus one. <i>This method is intended for Attribute sub classes, and is normally not needed by class generators or adapters.</i>

Parameters

• item: number the index a constant pool item.

Return Type

• number

Defined in: packages/asm/libs/ClassReader.ts:1747

getItemCount public

getItemCount(): number

Returns the number of constant pool items in [#b b].

Return Type

• number

Defined in: packages/asm/libs/ClassReader.ts:1734

getMaxStringLength public

getMaxStringLength(): number

Returns the maximum length of the strings contained in the constant pool of the class.

Return Type

• number

Defined in: packages/asm/libs/ClassReader.ts:1758

getSuperName public

getSuperName(): string

Returns the internal of name of the super class (see [Type#getInternalName() getInternalName]). For interfaces, the super class is [Object].

Return Type

• string

Defined in: packages/asm/libs/ClassReader.ts:244

readByte public

readByte(index: number): number

Reads a byte value in [#b b]. <i>This method is intended for Attribute sub classes, and is normally not needed by class generators or adapters.</i>

Parameters

• index: number the start index of the value to be read in [#b b].

Return Type

• number

Defined in: packages/asm/libs/ClassReader.ts:1770

readClass public

readClass(index: number, buf: number[]): string

Reads a class constant pool item in [#b b]. <i>This method is intended for Attribute sub classes, and is normally not needed by class generators or adapters.</i>

Parameters

• index: number the start index of an unsigned short value in [#b b], whose value is the index of a class constant pool item.
• buf: number[] buffer to be used to read the item. This buffer must be sufficiently large. It is not automatically resized.

Return Type

• string

Defined in: packages/asm/libs/ClassReader.ts:1906

readConst public

readConst(item: number, buf: number[]): any

Reads a numeric or string constant pool item in [#b b]. <i>This method is intended for Attribute sub classes, and is normally not needed by class generators or adapters.</i>

Parameters

• item: number the index of a constant pool item.
• buf: number[] buffer to be used to read the item. This buffer must be sufficiently large. It is not automatically resized.

Return Type

• any

Defined in: packages/asm/libs/ClassReader.ts:1922

readInt public

readInt(index: number): number

Reads a signed int value in [#b b]. <i>This method is intended for Attribute sub classes, and is normally not needed by class generators or adapters.</i>

Parameters

• index: number the start index of the value to be read in [#b b].

Return Type

• number

Defined in: packages/asm/libs/ClassReader.ts:1810

readLabel

readLabel(offset: number, labels: Label[]): Label

Returns the label corresponding to the given offset. The default implementation of this method creates a label for the given offset if it has not been already created.

Parameters

• offset: number a bytecode offset in a method.
• labels: Label[] the already created labels, indexed by their offset. If a label already exists for offset this method must not create a new one. Otherwise it must store the new label in this array.

Return Type

• Label

Defined in: packages/asm/libs/ClassReader.ts:1664

readLong public

readLong(index: number): bigint

Reads a signed long value in [#b b]. <i>This method is intended for Attribute sub classes, and is normally not needed by class generators or adapters.</i>

Parameters

• index: number the start index of the value to be read in [#b b].

Return Type

• bigint

Defined in: packages/asm/libs/ClassReader.ts:1824

readShort public

readShort(index: number): number

Reads a signed short value in [#b b]. <i>This method is intended for Attribute sub classes, and is normally not needed by class generators or adapters.</i>

Parameters

• index: number the start index of the value to be read in [#b b].

Return Type

• number

Defined in: packages/asm/libs/ClassReader.ts:1797

readUnsignedShort public

readUnsignedShort(index: number): number

Reads an unsigned short value in [#b b]. <i>This method is intended for Attribute sub classes, and is normally not needed by class generators or adapters.</i>

Parameters

• index: number the start index of the value to be read in [#b b].

Return Type

• number

Defined in: packages/asm/libs/ClassReader.ts:1783

readUTF8 public

readUTF8(index: number, buf: number[]): string

Reads an UTF8 string constant pool item in [#b b]. <i>This method is intended for Attribute sub classes, and is normally not needed by class generators or adapters.</i>

Parameters

• index: number the start index of an unsigned short value in [#b b], whose value is the index of an UTF8 constant pool item.
• buf: number[] buffer to be used to read the item. This buffer must be sufficiently large. It is not automatically resized.

Return Type

• string

Defined in: packages/asm/libs/ClassReader.ts:1841