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Support warning about useless cast on safe cast

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#KT-13348 Fixed
This commit is contained in:
Mikhail Zarechenskiy
2017-04-07 04:56:59 +03:00
parent 107879a78a
commit 7f287a4230
12 changed files with 56 additions and 23 deletions
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compiler/frontend/src/org/jetbrains/kotlin/psi/KtPsiUtil.java
+9 -1
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@@ -1,5 +1,5 @@
/*
* Copyright 2010-2016 JetBrains s.r.o.
* Copyright 2010-2017 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -541,6 +541,14 @@ public class KtPsiUtil {
((KtBinaryExpression) element).getOperationToken().equals(KtTokens.EQ);
}
public static boolean isSafeCast(@NotNull KtBinaryExpressionWithTypeRHS expression) {
return expression.getOperationReference().getReferencedNameElementType() == KtTokens.AS_SAFE;
}
public static boolean isUnsafeCast(@NotNull KtBinaryExpressionWithTypeRHS expression) {
return expression.getOperationReference().getReferencedNameElementType() == KtTokens.AS_KEYWORD;
}
public static boolean checkVariableDeclarationInBlock(@NotNull KtBlockExpression block, @NotNull String varName) {
for (KtExpression element : block.getStatements()) {
if (element instanceof KtVariableDeclaration) {
compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java
+5 -3
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@@ -26,7 +26,6 @@ import kotlin.TuplesKt;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.kotlin.KtNodeTypes;
import org.jetbrains.kotlin.builtins.FunctionTypesKt;
import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
import org.jetbrains.kotlin.config.LanguageFeature;
import org.jetbrains.kotlin.config.LanguageVersionSettings;
@@ -395,13 +394,16 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
@NotNull KotlinType actualType,
@NotNull KotlinTypeChecker typeChecker
) {
// Here: x as? Type <=> x as Type?
KotlinType refinedTargetType = KtPsiUtil.isSafeCast(expression) ? TypeUtils.makeNullable(targetType) : targetType;
Collection<KotlinType> possibleTypes = DataFlowAnalyzer.getAllPossibleTypes(expression.getLeft(), actualType, context);
KotlinType intersectedType = TypeIntersector.intersectTypes(typeChecker, possibleTypes);
if (intersectedType == null) return false;
return shouldCheckForExactType(expression, context.expectedType)
? isExactTypeCast(intersectedType, targetType)
: isUpcast(intersectedType, targetType, typeChecker);
? isExactTypeCast(intersectedType, refinedTargetType)
: isUpcast(intersectedType, refinedTargetType, typeChecker);
}
private static boolean shouldCheckForExactType(KtBinaryExpressionWithTypeRHS expression, KotlinType expectedType) {
compiler/testData/diagnostics/tests/Casts.kt
Vendored
+2 -2
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@@ -10,8 +10,8 @@ fun test() : Unit {
checkSubtype<Int>(y <!USELESS_CAST!>as Int<!>)
checkSubtype<Int?>(x as Int?)
checkSubtype<Int?>(y as Int?)
checkSubtype<Int?>(x <!USELESS_CAST!>as? Int<!>)
checkSubtype<Int?>(y <!USELESS_CAST!>as? Int<!>)
checkSubtype<Int?>(x as? Int)
checkSubtype<Int?>(y as? Int)
checkSubtype<Int?>(x as? Int?)
checkSubtype<Int?>(y as? Int?)
compiler/testData/diagnostics/tests/cast/UselessSafeCast.kt
Vendored
+22
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@@ -0,0 +1,22 @@
// !DIAGNOSTICS: -UNUSED_PARAMETER, -UNUSED_VARIABLE
fun test(x: Int?) {
val a1 = x <!USELESS_CAST!>as? Int<!>
val a2 = x <!USELESS_CAST!>as? Int?<!>
val a3 = x as? Number
val a4 = x as? Number?
val a5: Int? = x <!USELESS_CAST!>as? Int<!>
val a6: Number? = x <!USELESS_CAST!>as? Int<!>
val a7: Number? = 1 <!USELESS_CAST!>as? Number<!>
run { x <!USELESS_CAST!>as? Int<!> }
run { x as? Number }
foo(x as? Number)
if (x is Int) {
val b = x as? Int
}
}
fun foo(x: Number?) {}
compiler/testData/diagnostics/tests/cast/UselessSafeCast.txt
Vendored
+4
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@@ -0,0 +1,4 @@
package
public fun foo(/*0*/ x: kotlin.Number?): kotlin.Unit
public fun test(/*0*/ x: kotlin.Int?): kotlin.Unit
compiler/testData/diagnostics/tests/nullableTypes/uselessElvis.kt
Vendored
+1 -1
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@@ -33,7 +33,7 @@ fun test() {
if (x != null) {
takeNotNull(dependOn(x) <!USELESS_ELVIS!>?: ""<!>)
takeNotNull(dependOn(dependOn(x)) <!USELESS_ELVIS!>?: ""<!>)
takeNotNull(dependOn(dependOn(x) <!USELESS_CAST!>as? String<!>) ?: "")
takeNotNull(dependOn(dependOn(x) as? String) ?: "")
}
takeNotNull(bar()!!)
compiler/testData/diagnostics/tests/smartCasts/alwaysNull.kt
Vendored
+1 -1
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@@ -16,7 +16,7 @@ fun String?.gav() {}
fun bar(s: String?) {
if (s != null) return
<!DEBUG_INFO_CONSTANT!>s<!>.gav()
<!DEBUG_INFO_CONSTANT!>s<!> as? String
<!DEBUG_INFO_CONSTANT!>s<!> <!USELESS_CAST!>as? String<!>
<!DEBUG_INFO_CONSTANT!>s<!> <!USELESS_CAST!>as String?<!>
<!ALWAYS_NULL!>s<!> as String
}
compiler/testData/diagnostics/tests/smartCasts/extensionSafeCall.kt
Vendored
+1 -1
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@@ -7,7 +7,7 @@ fun <T> T?.let(f: (T) -> Unit) {
}
fun test(your: Your?) {
(your?.foo() as? Any)?.let {}
(your?.foo() <!USELESS_CAST!>as? Any<!>)?.let {}
// strange smart cast to 'Your' at this point
your<!UNSAFE_CALL!>.<!>hashCode()
}
compiler/testData/diagnostics/tests/smartCasts/safeAs.kt
Vendored
+2 -2
View File
@@ -1,13 +1,13 @@
// See also KT-10992: we should have no errors for all unsafe hashCode() calls
fun foo(arg: Any?) {
val x = arg as? Any ?: return
val x = arg <!USELESS_CAST!>as? Any<!> ?: return
<!DEBUG_INFO_SMARTCAST!>arg<!>.hashCode()
x.hashCode()
}
fun bar(arg: Any?) {
arg as? Any ?: return
arg <!USELESS_CAST!>as? Any<!> ?: return
<!DEBUG_INFO_SMARTCAST!>arg<!>.hashCode()
}
compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java
+6
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@@ -2974,6 +2974,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
doTest(fileName);
}
@TestMetadata("UselessSafeCast.kt")
public void testUselessSafeCast() throws Exception {
String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/cast/UselessSafeCast.kt");
doTest(fileName);
}
@TestMetadata("WhenErasedDisallowFromAny.kt")
public void testWhenErasedDisallowFromAny() throws Exception {
String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/cast/WhenErasedDisallowFromAny.kt");
idea/testData/checker/Casts.kt
Vendored
+1 -1
View File
@@ -11,7 +11,7 @@ fun test() : Unit {
checkSubtype<Int?>(x as Int?)
checkSubtype<Int?>(y as Int?)
checkSubtype<Int?>(x as Int?)
checkSubtype<Int?>(y <warning descr="[USELESS_CAST] No cast needed">as? Int</warning>)
checkSubtype<Int?>(y as? Int)
checkSubtype<Int?>(x as? Int?)
checkSubtype<Int?>(y as? Int?)
Unit
js/js.translator/src/org/jetbrains/kotlin/js/translate/expression/PatternTranslator.java
+2 -11
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@@ -1,5 +1,5 @@
/*
* Copyright 2010-2016 JetBrains s.r.o.
* Copyright 2010-2017 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -41,7 +41,6 @@ import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils;
import org.jetbrains.kotlin.js.translate.utils.BindingUtils;
import org.jetbrains.kotlin.js.translate.utils.JsAstUtils;
import org.jetbrains.kotlin.js.translate.utils.TranslationUtils;
import org.jetbrains.kotlin.lexer.KtTokens;
import org.jetbrains.kotlin.name.Name;
import org.jetbrains.kotlin.psi.KtBinaryExpressionWithTypeRHS;
import org.jetbrains.kotlin.psi.KtExpression;
@@ -59,7 +58,7 @@ import static org.jetbrains.kotlin.js.descriptorUtils.DescriptorUtilsKt.getNameI
import static org.jetbrains.kotlin.js.translate.utils.BindingUtils.getTypeByReference;
import static org.jetbrains.kotlin.js.translate.utils.JsAstUtils.equality;
import static org.jetbrains.kotlin.js.translate.utils.JsAstUtils.not;
import static org.jetbrains.kotlin.psi.KtPsiUtil.findChildByType;
import static org.jetbrains.kotlin.psi.KtPsiUtil.*;
import static org.jetbrains.kotlin.types.TypeUtils.*;
public final class PatternTranslator extends AbstractTranslator {
@@ -324,12 +323,4 @@ public final class PatternTranslator extends AbstractTranslator {
public JsExpression translateExpressionForExpressionPattern(@NotNull KtExpression patternExpression) {
return Translation.translateAsExpression(patternExpression, context());
}
private static boolean isSafeCast(@NotNull KtBinaryExpressionWithTypeRHS expression) {
return expression.getOperationReference().getReferencedNameElementType() == KtTokens.AS_SAFE;
}
private static boolean isUnsafeCast(@NotNull KtBinaryExpressionWithTypeRHS expression) {
return expression.getOperationReference().getReferencedNameElementType() == KtTokens.AS_KEYWORD;
}
}