Class WhileLoopAsmGenerator

java.lang.Object

org.ek9lang.compiler.backend.jvm.AbstractAsmGenerator

org.ek9lang.compiler.backend.jvm.AbstractControlFlowAsmGenerator

org.ek9lang.compiler.backend.jvm.WhileLoopAsmGenerator

final class WhileLoopAsmGenerator
extends AbstractControlFlowAsmGenerator

Specialized generator for EK9 while loops. Handles CONTROL_FLOW_CHAIN with chain_type: "WHILE_LOOP".

JVM Bytecode Pattern:

loop_start:
  [condition evaluation]
  iload primitive_condition
  ifeq loop_end              ; Exit if false
  [body instructions]
  goto loop_start            ; Iterate again
loop_end:

Stack Frame Invariant: Stack is empty before loop, after condition, after body, and after loop exit.

Nested Class Summary

Nested classes/interfaces inherited from class AbstractAsmGenerator

AbstractAsmGenerator.LocalVariableInfo, AbstractAsmGenerator.MethodContext, AbstractAsmGenerator.ScopeInfo, AbstractAsmGenerator.TempVariableSource

Field Summary

Fields inherited from class AbstractControlFlowAsmGenerator

context

Fields inherited from class AbstractAsmGenerator

classWriter, constructTargetTuple, outputVisitor

Constructor Summary

Constructors

Constructor	Description
WhileLoopAsmGenerator(ConstructTargetTuple constructTargetTuple, OutputVisitor outputVisitor, org.objectweb.asm.ClassWriter classWriter, BytecodeGenerationContext context)

Method Summary

Modifier and Type	Method	Description
void	generate(ControlFlowChainInstr instr)	Generate bytecode for while loop.

Methods inherited from class AbstractControlFlowAsmGenerator

branchIfFalse, branchIfTrue, copyResultVariable, createControlFlowLabel, jumpTo, placeLabel, processBodyEvaluation, processConditionCase, processConditionCaseWithoutLabelPlacement, processConditionEvaluation, processInstructions

Methods inherited from class AbstractAsmGenerator

convertBooleanToInt, convertToJvmDescriptor, convertToJvmName, generateBooleanLiteral, generateCharacterLiteral, generateDebugInfo, generateFloatLiteral, generateIntegerLiteral, generateLoadVariable, generateLocalVariableTable, generateMethodDescriptor, generateObjectLiteral, generateStackOperation, generateStoreVariable, generateStringLiteral, getCurrentMethodVisitor, getMethodContext, getOrCreateLabel, getVariableIndex, isVariableAllocated, setCurrentMethodVisitor, setSharedMethodContext, trackTempVariableFromLiteral, trackTempVariableFromLoad

Methods inherited from class Object

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

Constructor Details

WhileLoopAsmGenerator

WhileLoopAsmGenerator(ConstructTargetTuple constructTargetTuple,
 OutputVisitor outputVisitor,
 org.objectweb.asm.ClassWriter classWriter,
 BytecodeGenerationContext context)

Method Details

generate

public void generate(ControlFlowChainInstr instr)

Generate bytecode for while loop.

Control Flow:

1. Place loop start label
2. Evaluate condition (leaves stack empty)
3. Branch to loop end if condition is false
4. Execute body (leaves stack empty)
5. Jump back to loop start
6. Place loop end label

Stack Frame Invariant: Pre-condition: stack is empty Post-condition: stack is empty

Parameters:

instr - CONTROL_FLOW_CHAIN instruction with WHILE_LOOP type