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KT-2223 Comparing non-null value with null might produce helpful warning

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#KT-2223 Fixed
This commit is contained in:
Alexander Udalov
2012-06-20 17:20:45 +04:00
parent aed160e02a
commit d67e22b174
12 changed files with 92 additions and 46 deletions
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compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/autocasts/DataFlowInfo.java
+1 -1
View File
@@ -64,7 +64,7 @@ public class DataFlowInfo {
}
@NotNull
private Nullability getNullability(@NotNull DataFlowValue a) {
public Nullability getNullability(@NotNull DataFlowValue a) {
if (!a.isStableIdentifier()) return a.getImmanentNullability();
Nullability nullability = nullabilityInfo.get(a);
if (nullability == null) {
compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/BasicExpressionTypingVisitor.java
+32 -10
View File
@@ -35,6 +35,7 @@ import org.jetbrains.jet.lang.resolve.calls.OverloadResolutionResultsUtil;
import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowInfo;
import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowValue;
import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowValueFactory;
import org.jetbrains.jet.lang.resolve.calls.autocasts.Nullability;
import org.jetbrains.jet.lang.resolve.constants.*;
import org.jetbrains.jet.lang.resolve.constants.StringValue;
import org.jetbrains.jet.lang.resolve.name.LabelName;
@@ -1036,29 +1037,50 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
}
private void ensureNonemptyIntersectionOfOperandTypes(JetBinaryExpression expression, ExpressionTypingContext context) {
JetSimpleNameExpression operationSign = expression.getOperationReference();
JetExpression left = expression.getLeft();
JetExpression right = expression.getRight();
// TODO : duplicated effort for == and !=
JetType leftType = facade.getTypeInfo(left, context.replaceScope(context.scope)).getType();
JetType leftType = facade.getTypeInfo(left, context).getType();
if (leftType != null && right != null) {
JetType rightType = facade.getTypeInfo(right, context.replaceScope(context.scope)).getType();
JetType rightType = facade.getTypeInfo(right, context).getType();
if (rightType != null) {
if (TypeUtils.isIntersectionEmpty(leftType, rightType)) {
context.trace.report(EQUALITY_NOT_APPLICABLE.on(expression, operationSign, leftType, rightType));
context.trace.report(EQUALITY_NOT_APPLICABLE.on(expression, expression.getOperationReference(), leftType, rightType));
}
}
if (isSenselessComparisonWithNull(leftType, right) || isSenselessComparisonWithNull(rightType, left)) {
context.trace.report(SENSELESS_COMPARISON.on(expression, expression, operationSign.getReferencedNameElementType() == JetTokens.EXCLEQ));
checkSenselessComparisonWithNull(expression, left, right, context);
}
}
}
private boolean isSenselessComparisonWithNull(@Nullable JetType firstType, @NotNull JetExpression secondExpression) {
if (firstType == null) return false;
return !firstType.isNullable() && secondExpression instanceof JetConstantExpression && secondExpression.getNode().getElementType() == JetNodeTypes.NULL;
private void checkSenselessComparisonWithNull(@NotNull JetBinaryExpression expression, @NotNull JetExpression left, @NotNull JetExpression right, @NotNull ExpressionTypingContext context) {
JetExpression expr;
if (left instanceof JetConstantExpression && left.getNode().getElementType() == JetNodeTypes.NULL) {
expr = right;
}
else if (right instanceof JetConstantExpression && right.getNode().getElementType() == JetNodeTypes.NULL) {
expr = left;
}
else return;
JetSimpleNameExpression operationSign = expression.getOperationReference();
JetType type = facade.getTypeInfo(expr, context).getType();
DataFlowValue value = DataFlowValueFactory.INSTANCE.createDataFlowValue(expr, type, context.trace.getBindingContext());
Nullability nullability = context.dataFlowInfo.getNullability(value);
boolean expressionIsAlways;
boolean equality = operationSign.getReferencedNameElementType() == JetTokens.EQEQ || operationSign.getReferencedNameElementType() == JetTokens.EQEQEQ;
if (nullability == Nullability.NULL) {
expressionIsAlways = equality;
}
else if (nullability == Nullability.NOT_NULL) {
expressionIsAlways = !equality;
}
else return;
context.trace.report(SENSELESS_COMPARISON.on(expression, expression, expressionIsAlways));
}
protected JetType visitAssignmentOperation(JetBinaryExpression expression, ExpressionTypingContext context) {
compiler/testData/diagnostics/tests/Nullability.jet
+8 -7
View File
@@ -1,4 +1,3 @@
fun test() {
val a : Int? = 0
if (a != null) {
@@ -53,7 +52,7 @@ fun test() {
out?.println();
}
if (out == null || out != null && out.println() == #()) {
if (out == null || out.println() == #()) {
out?.println();
}
else {
@@ -109,7 +108,7 @@ fun test() {
out?.println();
}
if (out == null || out != null && out.println() == #()) {
if (out == null || out.println() == #()) {
out?.println();
}
else {
@@ -134,10 +133,12 @@ fun test() {
}
out?.println();
while (out == null) {
out?.println();
val out2 : java.io.PrintStream? = null
while (out2 == null) {
out2?.println();
}
out.println()
out2.println()
}
@@ -247,7 +248,7 @@ fun f7(s : String?, t : String?) {
}
s?.get(0)
t?.get(0)
if (!(s == null && s == null)) {
if (!(s == null)) {
s.get(0)
t?.get(0)
}
compiler/testData/diagnostics/tests/dataFlowInfoTraversal/DeepIf.jet
+6 -6
View File
@@ -5,24 +5,24 @@ fun foo() {
if (x != null) {
bar(x)
if (x != null) {
if (<!SENSELESS_COMPARISON!>x != null<!>) {
bar(x)
if (1 < 2) bar(x)
if (1 > 2) bar(x)
}
if (x == null) {
if (<!SENSELESS_COMPARISON!>x == null<!>) {
bar(x)
}
if (x == null) bar(x) else bar(x)
if (<!SENSELESS_COMPARISON!>x == null<!>) bar(x) else bar(x)
bar(bar(x))
} else if (x == null) {
} else if (<!SENSELESS_COMPARISON!>x == null<!>) {
bar(<!TYPE_MISMATCH!>x<!>)
if (x != null) {
if (<!SENSELESS_COMPARISON!>x != null<!>) {
bar(x)
if (x == null) bar(x)
if (x == null) bar(x) else bar(x)
bar(bar(x) + bar(x))
} else if (x == null) {
} else if (<!SENSELESS_COMPARISON!>x == null<!>) {
bar(<!TYPE_MISMATCH!>x<!>)
}
}
compiler/testData/diagnostics/tests/dataFlowInfoTraversal/ExclExcl.jet
+17 -7
View File
@@ -1,13 +1,23 @@
fun bar(x: Int) = x + 1
fun foo() {
val x: Int? = null
fun f1(x: Int?) {
bar(<!TYPE_MISMATCH!>x<!>)
if (x != null) bar(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
if (x == null) bar(x!!)
if (x != null) else bar(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
if (x == null) else bar(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
if (x != null) bar(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>) else bar(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
if (x == null) bar(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>) else bar(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
}
fun f2(x: Int?) {
if (x != null) else bar(x!!)
}
fun f3(x: Int?) {
if (x != null) bar(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>) else bar(x!!)
}
fun f4(x: Int?) {
if (x == null) bar(x!!) else bar(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
}
fun f5(x: Int?) {
if (x == null) else bar(x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
}
compiler/testData/diagnostics/tests/dataFlowInfoTraversal/For.jet
+1 -1
View File
@@ -12,7 +12,7 @@ fun foo() {
bar(x)
for (q in a) {
bar(x)
if (x == null) bar(x)
if (<!SENSELESS_COMPARISON!>x == null<!>) bar(x)
}
}
compiler/testData/diagnostics/tests/dataFlowInfoTraversal/IfThenElse.jet
+1 -1
View File
@@ -26,5 +26,5 @@ fun foo() {
if (z != null) bar(z)
bar(<!TYPE_MISMATCH!>z<!>)
bar(z!!)
if (z != null) bar(z<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
if (<!SENSELESS_COMPARISON!>z != null<!>) bar(z<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>)
}
compiler/testData/diagnostics/tests/dataFlowInfoTraversal/IfThenElseBothInvalid.jet
+1 -1
View File
@@ -9,7 +9,7 @@ fun foo() {
2+<!SYNTAX!><!>
}
else {
if (x == null) return
if (<!SENSELESS_COMPARISON!>x == null<!>) return
2+<!SYNTAX!><!>
}
bar(x)
compiler/testData/diagnostics/tests/dataFlowInfoTraversal/Return.jet
+8 -4
View File
@@ -5,8 +5,12 @@ fun foo(): Int {
bar(<!TYPE_MISMATCH!>x<!>)
if (x != null) return x
if (x == null) return if (x != null) x else <!TYPE_MISMATCH!>x<!>
if (x == null) return x
if (x != null) return if (x == null) x else x
return x
val y: Int? = null
if (y == null) return if (<!SENSELESS_COMPARISON!>y != null<!>) y else <!TYPE_MISMATCH!>y<!>
val z: Int? = null
if (z != null) return if (<!SENSELESS_COMPARISON!>z == null<!>) z else z
return <!TYPE_MISMATCH!>z<!>
}
compiler/testData/diagnostics/tests/dataFlowInfoTraversal/Throw.jet
+1 -2
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@@ -3,8 +3,7 @@ fun bar(x: Int): RuntimeException = RuntimeException(x.toString())
fun foo() {
val x: Int? = null
if (x == null || 1 < 2) throw bar(<!TYPE_MISMATCH!>x<!>)
if (x == null) return
if (x == null) throw bar(<!TYPE_MISMATCH!>x<!>)
throw bar(x)
throw <!UNREACHABLE_CODE!>bar(x)<!>
}
compiler/testData/diagnostics/tests/nullabilityAndAutoCasts/kt2223.jet
+8
View File
@@ -0,0 +1,8 @@
//KT-2223 Comparing non-null value with null might produce helpful warning
package kt2223
fun foo() {
val x: Int? = null
if (x == null) return
if (<!SENSELESS_COMPARISON!>x == null<!>) return
}
idea/testData/checker/Nullability.jet
+8 -6
View File
@@ -52,7 +52,7 @@ fun test() {
out?.println();
}
if (out == null || out != null && out.println() == #()) {
if (out == null || out.println() == #()) {
out?.println();
}
else {
@@ -108,7 +108,7 @@ fun test() {
out?.println();
}
if (out == null || out != null && out.println() == #()) {
if (out == null || out.println() == #()) {
out?.println();
}
else {
@@ -133,10 +133,12 @@ fun test() {
}
out?.println();
while (out == null) {
out?.println();
val out2 : java.io.PrintStream? = null
while (out2 == null) {
out2?.println();
}
out.println()
out2.println()
}
@@ -246,7 +248,7 @@ fun f7(s : String?, t : String?) {
}
s?.get(0)
t?.get(0)
if (!(s == null && s == null)) {
if (!(s == null)) {
s.get(0)
t?.get(0)
}