Java ClassFileConstants.ATTR_VARS属性代码示例

public void exitUserScope(BlockScope currentScope) {
	// mark all the scope's locals as losing their definite assignment
	if ((this.generateAttributes & (ClassFileConstants.ATTR_VARS
			| ClassFileConstants.ATTR_STACK_MAP_TABLE
			| ClassFileConstants.ATTR_STACK_MAP)) == 0)
		return;
	int index = this.visibleLocalsCount - 1;
	while (index >= 0) {
		LocalVariableBinding visibleLocal = this.visibleLocals[index];
		if (visibleLocal == null || visibleLocal.declaringScope != currentScope) {
			// left currentScope
			index--;
			continue;
		}

		// there may be some preserved locals never initialized
		if (visibleLocal.initializationCount > 0) {
			visibleLocal.recordInitializationEndPC(this.position);
		}
		this.visibleLocals[index--] = null; // this variable is no longer visible afterwards
	}
}
 

public void addDefinitelyAssignedVariables(Scope scope, int initStateIndex) {
	// Required to fix 1PR0XVS: LFRE:WINNT - Compiler: variable table for method appears incorrect
	if ((this.generateAttributes & (ClassFileConstants.ATTR_VARS
			| ClassFileConstants.ATTR_STACK_MAP_TABLE
			| ClassFileConstants.ATTR_STACK_MAP)) == 0)
		return;
	for (int i = 0; i < this.visibleLocalsCount; i++) {
		LocalVariableBinding localBinding = this.visibleLocals[i];
		if (localBinding != null) {
			// Check if the local is definitely assigned
			if (isDefinitelyAssigned(scope, initStateIndex, localBinding)) {
				if ((localBinding.initializationCount == 0) || (localBinding.initializationPCs[((localBinding.initializationCount - 1) << 1) + 1] != -1)) {
					/* There are two cases:
					 * 1) there is no initialization interval opened ==> add an opened interval
					 * 2) there is already some initialization intervals but the last one is closed ==> add an opened interval
					 * An opened interval means that the value at localBinding.initializationPCs[localBinding.initializationCount - 1][1]
					 * is equals to -1.
					 * initializationPCs is a collection of pairs of int:
					 * 	first value is the startPC and second value is the endPC. -1 one for the last value means that the interval
					 * 	is not closed yet.
					 */
					localBinding.recordInitializationStartPC(this.position);
				}
			}
		}
	}
}
 

public void addVisibleLocalVariable(LocalVariableBinding localBinding) {
	if ((this.generateAttributes & (ClassFileConstants.ATTR_VARS
			| ClassFileConstants.ATTR_STACK_MAP_TABLE
			| ClassFileConstants.ATTR_STACK_MAP)) == 0)
		return;

	if (this.visibleLocalsCount >= this.visibleLocals.length)
		System.arraycopy(this.visibleLocals, 0, this.visibleLocals = new LocalVariableBinding[this.visibleLocalsCount * 2], 0, this.visibleLocalsCount);
	this.visibleLocals[this.visibleLocalsCount++] = localBinding;
}
 

public void record(LocalVariableBinding local) {
	if ((this.generateAttributes & (ClassFileConstants.ATTR_VARS
			| ClassFileConstants.ATTR_STACK_MAP_TABLE
			| ClassFileConstants.ATTR_STACK_MAP)) == 0)
		return;
	if (this.allLocalsCounter == this.locals.length) {
		// resize the collection
		System.arraycopy(this.locals, 0, this.locals = new LocalVariableBinding[this.allLocalsCounter + LOCALS_INCREMENT], 0, this.allLocalsCounter);
	}
	this.locals[this.allLocalsCounter++] = local;
	local.initializationPCs = new int[4];
	local.initializationCount = 0;
}
 

public void removeNotDefinitelyAssignedVariables(Scope scope, int initStateIndex) {
	// given some flow info, make sure we did not loose some variables initialization
	// if this happens, then we must update their pc entries to reflect it in debug attributes
	if ((this.generateAttributes & (ClassFileConstants.ATTR_VARS
			| ClassFileConstants.ATTR_STACK_MAP_TABLE
			| ClassFileConstants.ATTR_STACK_MAP)) == 0)
		return;
	for (int i = 0; i < this.visibleLocalsCount; i++) {
		LocalVariableBinding localBinding = this.visibleLocals[i];
		if (localBinding != null && !isDefinitelyAssigned(scope, initStateIndex, localBinding) && localBinding.initializationCount > 0) {
			localBinding.recordInitializationEndPC(this.position);
		}
	}
}
 

public void place() { // Currently lacking wide support.
//	if ((this.tagBits & USED) == 0 && this.forwardReferenceCount == 0) {
//		return;
//	}

	//TODO how can position be set already ? cannot place more than once
	if (this.position == Label.POS_NOT_SET) {
		this.position = this.codeStream.position;
		this.codeStream.addLabel(this);
		int oldPosition = this.position;
		boolean isOptimizedBranch = false;
		if (this.forwardReferenceCount != 0) {
			isOptimizedBranch = (this.forwardReferences[this.forwardReferenceCount - 1] + 2 == this.position) && (this.codeStream.bCodeStream[this.codeStream.classFileOffset - 3] == Opcodes.OPC_goto);
			if (isOptimizedBranch) {
				if (this.codeStream.lastAbruptCompletion == this.position) {
					this.codeStream.lastAbruptCompletion = -1;
				}
				this.codeStream.position = (this.position -= 3);
				this.codeStream.classFileOffset -= 3;
				this.forwardReferenceCount--;
				if (this.codeStream.lastEntryPC == oldPosition) {
					this.codeStream.lastEntryPC = this.position;
				}
				// end of new code
				if ((this.codeStream.generateAttributes & (ClassFileConstants.ATTR_VARS | ClassFileConstants.ATTR_STACK_MAP_TABLE | ClassFileConstants.ATTR_STACK_MAP)) != 0) {
					LocalVariableBinding locals[] = this.codeStream.locals;
					for (int i = 0, max = locals.length; i < max; i++) {
						LocalVariableBinding local = locals[i];
						if ((local != null) && (local.initializationCount > 0)) {
							if (local.initializationPCs[((local.initializationCount - 1) << 1) + 1] == oldPosition) {
								// we want to prevent interval of size 0 to have a negative size.
								// see PR 1GIRQLA: ITPJCORE:ALL - ClassFormatError for local variable attribute
								local.initializationPCs[((local.initializationCount - 1) << 1) + 1] = this.position;
							}
							if (local.initializationPCs[(local.initializationCount - 1) << 1] == oldPosition) {
								local.initializationPCs[(local.initializationCount - 1) << 1] = this.position;
							}
						}
					}
				}
				if ((this.codeStream.generateAttributes & ClassFileConstants.ATTR_LINES) != 0) {
					// we need to remove all entries that is beyond this.position inside the pcToSourcerMap table
					this.codeStream.removeUnusedPcToSourceMapEntries();
				}
			}
		}
		for (int i = 0; i < this.forwardReferenceCount; i++) {
			this.codeStream.writePosition(this, this.forwardReferences[i]);
		}
		// For all labels placed at that position we check if we need to rewrite the jump
		// offset. It is the case each time a label had a forward reference to the current position.
		// Like we change the current position, we have to change the jump offset. See 1F4IRD9 for more details.
		if (isOptimizedBranch) {
			this.codeStream.optimizeBranch(oldPosition, this);
		}
	}
}