com.android.dx.dex.code

Class InsnFormat

java.lang.Object

com.android.dx.dex.code.InsnFormat

Direct Known Subclasses:

Form10t, Form10x, Form11n, Form11x, Form12x, Form20t, Form21c, Form21h, Form21s, Form21t, Form22b, Form22c, Form22s, Form22t, Form22x, Form23x, Form30t, Form31c, Form31i, Form31t, Form32x, Form35c, Form3rc, Form45cc, Form4rcc, Form51l, SpecialFormat

public abstract class InsnFormat
extends java.lang.Object

Base class for all instruction format handlers. Instruction format handlers know how to translate DalvInsn instances into streams of code units, as well as human-oriented listing strings representing such translations.

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	ALLOW_EXTENDED_OPCODES flag to enable/disable the new extended opcode formats; meant as a temporary measure until VM support for the salient opcodes is added.

Constructor Summary

Constructors

Constructor and Description
InsnFormat()

Method Summary

Modifier and Type	Method and Description
protected static int	argIndex(DalvInsn insn) Helper method to extract the callout-argument index from an appropriate instruction.
protected static java.lang.String	branchComment(DalvInsn insn) Helper method to return the comment for a branch.
boolean	branchFits(TargetInsn insn) Returns whether or not the given instruction's branch offset will fit in this instance's format.
protected static java.lang.String	branchString(DalvInsn insn) Helper method to return a branch address string.
abstract int	codeSize() Gets the code size of instructions that use this format.
protected static short	codeUnit(int low, int high) Helper method to combine two bytes into a code unit.
protected static short	codeUnit(int n0, int n1, int n2, int n3) Helper method to combine four nibbles into a code unit.
java.util.BitSet	compatibleRegs(DalvInsn insn) Returns which of a given instruction's registers will fit in this instance's format.
abstract java.lang.String	insnArgString(DalvInsn insn) Returns the string form of the arguments to the given instruction.
abstract java.lang.String	insnCommentString(DalvInsn insn, boolean noteIndices) Returns the associated comment for the given instruction, if any.
abstract boolean	isCompatible(DalvInsn insn) Returns whether or not the given instruction's arguments will fit in this instance's format.
protected static boolean	isRegListSequential(RegisterSpecList list) Helper method to determine if a list of registers are sequential, including degenerate cases for empty or single-element lists.
java.lang.String	listingString(DalvInsn insn, boolean noteIndices) Returns the string form, suitable for inclusion in a listing dump, of the given instruction.
protected static java.lang.String	literalBitsComment(CstLiteralBits value, int width) Helper method to return a literal bits comment string.
protected static java.lang.String	literalBitsString(CstLiteralBits value) Helper method to return a literal bits argument string.
protected static int	makeByte(int low, int high) Helper method to combine two nibbles into a byte.
protected static short	opcodeUnit(DalvInsn insn) Helper method to get an extended (16-bit) opcode out of an instruction, returning it as a code unit.
protected static short	opcodeUnit(DalvInsn insn, int arg) Helper method to combine an opcode and a second byte of data into the appropriate form for emitting into a code buffer.
protected static java.lang.String	regListString(RegisterSpecList list) Helper method to return a register list string.
protected static java.lang.String	regRangeString(RegisterSpecList list) Helper method to return a register range string.
protected static boolean	signedFitsInByte(int value) Helper method to determine if a signed int value fits in a byte.
protected static boolean	signedFitsInNibble(int value) Helper method to determine if a signed int value fits in a nibble.
protected static boolean	signedFitsInShort(int value) Helper method to determine if a signed int value fits in a short.
protected static boolean	unsignedFitsInByte(int value) Helper method to determine if an unsigned int value fits in a byte.
protected static boolean	unsignedFitsInNibble(int value) Helper method to determine if an unsigned int value fits in a nibble.
protected static boolean	unsignedFitsInShort(int value) Helper method to determine if an unsigned int value fits in a short.
protected static void	write(AnnotatedOutput out, short c0) Writes one code unit to the given output destination.
protected static void	write(AnnotatedOutput out, short c0, int c1c2) Writes three code units to the given output destination, where the second and third are represented as single int and emitted in little-endian order.
protected static void	write(AnnotatedOutput out, short c0, int c1c2, short c3) Writes four code units to the given output destination, where the second and third are represented as single int and emitted in little-endian order.
protected static void	write(AnnotatedOutput out, short c0, int c1c2, short c3, short c4) Writes five code units to the given output destination, where the second and third are represented as single int and emitted in little-endian order.
protected static void	write(AnnotatedOutput out, short c0, long c1c2c3c4) Writes five code units to the given output destination, where the second through fifth are represented as single long and emitted in little-endian order.
protected static void	write(AnnotatedOutput out, short c0, short c1) Writes two code units to the given output destination.
protected static void	write(AnnotatedOutput out, short c0, short c1, short c2) Writes three code units to the given output destination.
protected static void	write(AnnotatedOutput out, short c0, short c1, short c2, short c3) Writes four code units to the given output destination.
protected static void	write(AnnotatedOutput out, short c0, short c1, short c2, short c3, short c4) Writes five code units to the given output destination.
abstract void	writeTo(AnnotatedOutput out, DalvInsn insn) Writes the code units for the given instruction to the given output destination.

Methods inherited from class java.lang.Object

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

Field Detail

ALLOW_EXTENDED_OPCODES

public static final boolean ALLOW_EXTENDED_OPCODES

flag to enable/disable the new extended opcode formats; meant as a temporary measure until VM support for the salient opcodes is added. TODO: Remove this declaration when the VM can deal.

See Also:

Constant Field Values

Constructor Detail

InsnFormat

public InsnFormat()

Method Detail

listingString

public final java.lang.String listingString(DalvInsn insn,
                                            boolean noteIndices)

Returns the string form, suitable for inclusion in a listing dump, of the given instruction. The instruction must be of this instance's format for proper operation.

Parameters:

insn - non-null; the instruction

noteIndices - whether to include an explicit notation of constant pool indices

Returns:

non-null; the string form

insnArgString

public abstract java.lang.String insnArgString(DalvInsn insn)

Returns the string form of the arguments to the given instruction. The instruction must be of this instance's format. If the instruction has no arguments, then the result should be "", not null.

Subclasses must override this method.

Parameters:

insn - non-null; the instruction

Returns:

non-null; the string form

insnCommentString

public abstract java.lang.String insnCommentString(DalvInsn insn,
                                                   boolean noteIndices)

Returns the associated comment for the given instruction, if any. The instruction must be of this instance's format. If the instruction has no comment, then the result should be "", not null.

Subclasses must override this method.

Parameters:

insn - non-null; the instruction

noteIndices - whether to include an explicit notation of constant pool indices

Returns:

non-null; the string form

codeSize

public abstract int codeSize()

Gets the code size of instructions that use this format. The size is a number of 16-bit code units, not bytes. This should throw an exception if this format is of variable size.

Returns:

>= 0; the instruction length in 16-bit code units

isCompatible

public abstract boolean isCompatible(DalvInsn insn)

Returns whether or not the given instruction's arguments will fit in this instance's format. This includes such things as counting register arguments, checking register ranges, and making sure that additional arguments are of appropriate types and are in-range. If this format has a branch target but the instruction's branch offset is unknown, this method will simply not check the offset.

Subclasses must override this method.

Parameters:

insn - non-null; the instruction to check

Returns:

true iff the instruction's arguments are appropriate for this instance, or false if not

compatibleRegs

public java.util.BitSet compatibleRegs(DalvInsn insn)

Returns which of a given instruction's registers will fit in this instance's format.

The default implementation of this method always returns an empty BitSet. Subclasses must override this method if they have registers.

Parameters:

insn - non-null; the instruction to check

Returns:

non-null; a BitSet flagging registers in the register list that are compatible to this format

branchFits

public boolean branchFits(TargetInsn insn)

Returns whether or not the given instruction's branch offset will fit in this instance's format. This always returns false for formats that don't include a branch offset.

The default implementation of this method always returns false. Subclasses must override this method if they include branch offsets.

Parameters:

insn - non-null; the instruction to check

Returns:

true iff the instruction's branch offset is appropriate for this instance, or false if not

writeTo

public abstract void writeTo(AnnotatedOutput out,
                             DalvInsn insn)

Writes the code units for the given instruction to the given output destination. The instruction must be of this instance's format.

Subclasses must override this method.

Parameters:

out - non-null; the output destination to write to

insn - non-null; the instruction to write

regListString

protected static java.lang.String regListString(RegisterSpecList list)

Helper method to return a register list string.

Parameters:

list - non-null; the list of registers

Returns:

non-null; the string form

regRangeString

protected static java.lang.String regRangeString(RegisterSpecList list)

Helper method to return a register range string.

Parameters:

list - non-null; the list of registers (which must be sequential)

Returns:

non-null; the string form

literalBitsString

protected static java.lang.String literalBitsString(CstLiteralBits value)

Helper method to return a literal bits argument string.

Parameters:

value - the value

Returns:

non-null; the string form

literalBitsComment

protected static java.lang.String literalBitsComment(CstLiteralBits value,
                                                     int width)

Helper method to return a literal bits comment string.

Parameters:

value - the value

width - the width of the constant, in bits (used for displaying the uninterpreted bits; one of: 4 8 16 32 64

Returns:

non-null; the comment

branchString

protected static java.lang.String branchString(DalvInsn insn)

Helper method to return a branch address string.

Parameters:

insn - non-null; the instruction in question

Returns:

non-null; the string form of the instruction's branch target

branchComment

protected static java.lang.String branchComment(DalvInsn insn)

Helper method to return the comment for a branch.

Parameters:

insn - non-null; the instruction in question

Returns:

non-null; the comment

signedFitsInNibble

protected static boolean signedFitsInNibble(int value)

Helper method to determine if a signed int value fits in a nibble.

Parameters:

value - the value in question

Returns:

true iff it's in the range -8..+7

unsignedFitsInNibble

protected static boolean unsignedFitsInNibble(int value)

Helper method to determine if an unsigned int value fits in a nibble.

Parameters:

value - the value in question

Returns:

true iff it's in the range 0..0xf

signedFitsInByte

protected static boolean signedFitsInByte(int value)

Helper method to determine if a signed int value fits in a byte.

Parameters:

value - the value in question

Returns:

true iff it's in the range -0x80..+0x7f

unsignedFitsInByte

protected static boolean unsignedFitsInByte(int value)

Helper method to determine if an unsigned int value fits in a byte.

Parameters:

value - the value in question

Returns:

true iff it's in the range 0..0xff

signedFitsInShort

protected static boolean signedFitsInShort(int value)

Helper method to determine if a signed int value fits in a short.

Parameters:

value - the value in question

Returns:

true iff it's in the range -0x8000..+0x7fff

unsignedFitsInShort

protected static boolean unsignedFitsInShort(int value)

Helper method to determine if an unsigned int value fits in a short.

Parameters:

value - the value in question

Returns:

true iff it's in the range 0..0xffff

isRegListSequential

protected static boolean isRegListSequential(RegisterSpecList list)

Helper method to determine if a list of registers are sequential, including degenerate cases for empty or single-element lists.

Parameters:

list - non-null; the list of registers

Returns:

true iff the list is sequentially ordered

argIndex

protected static int argIndex(DalvInsn insn)

Helper method to extract the callout-argument index from an appropriate instruction.

Parameters:

insn - non-null; the instruction

Returns:

>= 0; the callout argument index

opcodeUnit

protected static short opcodeUnit(DalvInsn insn,
                                  int arg)

Helper method to combine an opcode and a second byte of data into the appropriate form for emitting into a code buffer.

Parameters:

insn - non-null; the instruction containing the opcode

arg - 0..255; arbitrary other byte value

Returns:

combined value

opcodeUnit

protected static short opcodeUnit(DalvInsn insn)

Helper method to get an extended (16-bit) opcode out of an instruction, returning it as a code unit. The opcode must be an extended opcode.

Parameters:

insn - non-null; the instruction containing the extended opcode

Returns:

the opcode as a code unit

codeUnit

protected static short codeUnit(int low,
                                int high)

Helper method to combine two bytes into a code unit.

Parameters:

low - 0..255; low byte

high - 0..255; high byte

Returns:

combined value

codeUnit

protected static short codeUnit(int n0,
                                int n1,
                                int n2,
                                int n3)

Helper method to combine four nibbles into a code unit.

Parameters:

n0 - 0..15; low nibble

n1 - 0..15; medium-low nibble

n2 - 0..15; medium-high nibble

n3 - 0..15; high nibble

Returns:

combined value

makeByte

protected static int makeByte(int low,
                              int high)

Helper method to combine two nibbles into a byte.

Parameters:

low - 0..15; low nibble

high - 0..15; high nibble

Returns:

0..255; combined value

write

protected static void write(AnnotatedOutput out,
                            short c0)

Writes one code unit to the given output destination.

Parameters:

out - non-null; where to write to

c0 - code unit to write

write

protected static void write(AnnotatedOutput out,
                            short c0,
                            short c1)

Writes two code units to the given output destination.

Parameters:

out - non-null; where to write to

c0 - code unit to write

c1 - code unit to write

write

protected static void write(AnnotatedOutput out,
                            short c0,
                            short c1,
                            short c2)

Writes three code units to the given output destination.

Parameters:

out - non-null; where to write to

c0 - code unit to write

c1 - code unit to write

c2 - code unit to write

write

protected static void write(AnnotatedOutput out,
                            short c0,
                            short c1,
                            short c2,
                            short c3)

Writes four code units to the given output destination.

Parameters:

out - non-null; where to write to

c0 - code unit to write

c1 - code unit to write

c2 - code unit to write

c3 - code unit to write

write

protected static void write(AnnotatedOutput out,
                            short c0,
                            short c1,
                            short c2,
                            short c3,
                            short c4)

Writes five code units to the given output destination.

Parameters:

out - non-null; where to write to

c0 - code unit to write

c1 - code unit to write

c2 - code unit to write

c3 - code unit to write

c4 - code unit to write

write

protected static void write(AnnotatedOutput out,
                            short c0,
                            int c1c2)

Writes three code units to the given output destination, where the second and third are represented as single int and emitted in little-endian order.

Parameters:

out - non-null; where to write to

c0 - code unit to write

c1c2 - code unit pair to write

write

protected static void write(AnnotatedOutput out,
                            short c0,
                            int c1c2,
                            short c3)

Writes four code units to the given output destination, where the second and third are represented as single int and emitted in little-endian order.

Parameters:

out - non-null; where to write to

c0 - code unit to write

c1c2 - code unit pair to write

c3 - code unit to write

write

protected static void write(AnnotatedOutput out,
                            short c0,
                            int c1c2,
                            short c3,
                            short c4)

Writes five code units to the given output destination, where the second and third are represented as single int and emitted in little-endian order.

Parameters:

out - non-null; where to write to

c0 - code unit to write

c1c2 - code unit pair to write

c3 - code unit to write

c4 - code unit to write

write

protected static void write(AnnotatedOutput out,
                            short c0,
                            long c1c2c3c4)

Writes five code units to the given output destination, where the second through fifth are represented as single long and emitted in little-endian order.

Parameters:

out - non-null; where to write to

c0 - code unit to write

c1c2c3c4 - code unit quad to write