Interface StackMapFrameInfo

public sealed interface StackMapFrameInfo

Models a stack map frame in a StackMapTable attribute (JVMS Â§4.7.4). A stack map frame must appear at the beginning of each basic block in a method (JVMS Â§4.10.1).

API Note:

In general, a stack map frame should be defined for each target of a BranchInstruction, or unreachable code right after an unconditional branch instruction like goto. The automatic stack map generation cannot handle unreachable code right after an unconditional jump; The ClassFile.DeadCodeOption allows substituting such code, or advanced users can provide their own stack maps for dead code.

See Java Virtual Machine Specification:

4.7.4 The StackMapTable Attribute
4.10.1 Verification by Type Checking

Since:

See Also:

Nested Class Summary

Modifier and Type	Interface	Description
`static interface`	`StackMapFrameInfo.ObjectVerificationTypeInfo`	A stack value for an object type.
`static enum`	`StackMapFrameInfo.SimpleVerificationTypeInfo`	A simple stack value.
`static interface`	`StackMapFrameInfo.UninitializedVerificationTypeInfo`	An uninitialized stack value.
`static interface`	`StackMapFrameInfo.VerificationTypeInfo`	The type of a stack or local variable value.

Method Summary

Modifier and Type	Method	Description
`int`	`frameType()`	Returns the raw `u1 frame_type`.
`List<StackMapFrameInfo.VerificationTypeInfo>`	`locals()`	Returns the expanded local variable types.
`static StackMapFrameInfo`	`of(Label target, List<StackMapFrameInfo.VerificationTypeInfo> locals, List<StackMapFrameInfo.VerificationTypeInfo> stack)`	Returns a new stack map frame.
`List<StackMapFrameInfo.VerificationTypeInfo>`	`stack()`	Returns the expanded operand stack types.
`Label`	`target()`	Returns the frame target label.

Method Details

frameType

int frameType()

Returns the raw u1 frame_type.

Returns:: the raw u1 frame_type

target

Label target()

Returns the frame target label.

Returns:: the frame target label

locals

List<StackMapFrameInfo.VerificationTypeInfo> locals()

Returns the expanded local variable types.

Returns:: the expanded local variable types

stack

List<StackMapFrameInfo.VerificationTypeInfo> stack()

Returns the expanded operand stack types.

Returns:: the expanded operand stack types

of

static StackMapFrameInfo of(Label target, List<StackMapFrameInfo.VerificationTypeInfo> locals, List<StackMapFrameInfo.VerificationTypeInfo> stack)

Returns a new stack map frame.

Parameters:: target - the location of the frame; locals - the complete list of frame locals; stack - the complete frame stack
Returns:: a new stack map frame
Throws:: IllegalArgumentException - if the number of types in locals or stack exceeds the limit of u2

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