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One more case for nullability: comparison to a non-null expression

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This commit is contained in:
Andrey Breslav
2011-06-12 15:32:50 +04:00
parent 70ed1f8083
commit 11c0d924a6
2 changed files with 52 additions and 16 deletions
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idea/src/org/jetbrains/jet/lang/types/JetTypeInferrer.java
+35 -16
View File
@@ -1381,24 +1381,39 @@ public class JetTypeInferrer {
|| operationToken == JetTokens.EXCLEQEQEQ) {
JetExpression left = expression.getLeft();
JetExpression right = expression.getRight();
if (left instanceof JetConstantExpression) {
if (right == null) return;
if (!(left instanceof JetSimpleNameExpression)) {
JetExpression tmp = left;
left = right;
right = tmp;
if (!(left instanceof JetSimpleNameExpression)) {
return;
}
}
if (!(left instanceof JetSimpleNameExpression)) {
return;
}
JetSimpleNameExpression nameExpression = (JetSimpleNameExpression) left;
DeclarationDescriptor declarationDescriptor = trace.getBindingContext().resolveReferenceExpression(nameExpression);
if (!(declarationDescriptor instanceof VariableDescriptor)) {
return;
}
VariableDescriptor variableDescriptor = (VariableDescriptor) declarationDescriptor;
VariableDescriptor variableDescriptor = getVariableDescriptorFromSimpleName(left);
// TODO : validate that DF makes sense for this variable: local, val, internal w/backing field, etc
// Comparison to a non-null expression
JetType rhsType = trace.getBindingContext().getExpressionType(right);
if (rhsType != null && !rhsType.isNullable()) {
extendDataFlowWithNullComparison(operationToken, variableDescriptor, !conditionValue);
return;
}
VariableDescriptor rightVariable = getVariableDescriptorFromSimpleName(right);
if (rightVariable != null) {
JetType lhsType = trace.getBindingContext().getExpressionType(left);
if (lhsType != null && !lhsType.isNullable()) {
extendDataFlowWithNullComparison(operationToken, rightVariable, !conditionValue);
return;
}
}
// Comparison to 'null'
if (!(right instanceof JetConstantExpression)) {
return;
}
@@ -1407,12 +1422,16 @@ public class JetTypeInferrer {
return;
}
if (operationToken == JetTokens.EQEQ || operationToken == JetTokens.EQEQEQ) {
result[0] = dataFlowInfo.equalsToNull(variableDescriptor, !conditionValue);
}
else if (operationToken == JetTokens.EXCLEQ || operationToken == JetTokens.EXCLEQEQEQ) {
result[0] = dataFlowInfo.equalsToNull(variableDescriptor, conditionValue);
}
extendDataFlowWithNullComparison(operationToken, variableDescriptor, conditionValue);
}
}
private void extendDataFlowWithNullComparison(IElementType operationToken, VariableDescriptor variableDescriptor, boolean equalsToNull) {
if (operationToken == JetTokens.EQEQ || operationToken == JetTokens.EQEQEQ) {
result[0] = dataFlowInfo.equalsToNull(variableDescriptor, !equalsToNull);
}
else if (operationToken == JetTokens.EXCLEQ || operationToken == JetTokens.EXCLEQEQEQ) {
result[0] = dataFlowInfo.equalsToNull(variableDescriptor, equalsToNull);
}
}
idea/testData/checker/Nullability.jet
+17
View File
@@ -255,3 +255,20 @@ fun f7(s : String?, t : String?) {
t?.get(0)
}
}
fun f8(b : String?, a : String) {
b?.get(0)
if (b == a) {
b.get(0);
}
b?.get(0)
if (a == b) {
b.get(0)
}
if (a != b) {
b?.get(0)
}
else {
b.get(0)
}
}