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'Cast can never succeed' diagnostics improved

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This commit is contained in:
Andrey Breslav
2013-09-04 13:12:07 +04:00
parent 9f4beece64
commit a28d211442
6 changed files with 250 additions and 9 deletions
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compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/BasicExpressionTypingVisitor.java
+80 -8
View File
@@ -35,7 +35,9 @@ 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.calls.context.*;
import org.jetbrains.jet.lang.resolve.calls.context.CheckValueArgumentsMode;
import org.jetbrains.jet.lang.resolve.calls.context.ExpressionPosition;
import org.jetbrains.jet.lang.resolve.calls.context.TemporaryTraceAndCache;
import org.jetbrains.jet.lang.resolve.calls.model.ResolvedCall;
import org.jetbrains.jet.lang.resolve.calls.model.ResolvedCallWithTrace;
import org.jetbrains.jet.lang.resolve.calls.model.VariableAsFunctionResolvedCall;
@@ -71,7 +73,8 @@ import static org.jetbrains.jet.lang.resolve.calls.context.ContextDependency.IND
import static org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue.NO_RECEIVER;
import static org.jetbrains.jet.lang.types.TypeUtils.NO_EXPECTED_TYPE;
import static org.jetbrains.jet.lang.types.TypeUtils.noExpectedType;
import static org.jetbrains.jet.lang.types.expressions.ControlStructureTypingUtils.*;
import static org.jetbrains.jet.lang.types.expressions.ControlStructureTypingUtils.createCallForSpecialConstruction;
import static org.jetbrains.jet.lang.types.expressions.ControlStructureTypingUtils.resolveSpecialConstructionAsCall;
import static org.jetbrains.jet.lang.types.expressions.ExpressionTypingUtils.*;
@SuppressWarnings("SuspiciousMethodCalls")
@@ -190,7 +193,7 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
return DataFlowUtils.checkType(result, expression, context, dataFlowInfo);
}
private static void checkBinaryWithTypeRHS(
private void checkBinaryWithTypeRHS(
@NotNull JetBinaryExpressionWithTypeRHS expression,
@NotNull ExpressionTypingContext context,
@NotNull JetType targetType,
@@ -209,7 +212,7 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
checkForCastImpossibility(expression, actualType, targetType, context);
}
private static void checkForCastImpossibility(
private void checkForCastImpossibility(
JetBinaryExpressionWithTypeRHS expression,
JetType actualType,
JetType targetType,
@@ -217,15 +220,15 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
) {
if (actualType == null || noExpectedType(targetType)) return;
if (!isCastPossible(actualType, targetType)) {
context.trace.report(CAST_NEVER_SUCCEEDS.on(expression.getOperationReference()));
}
JetTypeChecker typeChecker = JetTypeChecker.INSTANCE;
if (!typeChecker.isSubtypeOf(targetType, actualType)) {
if (typeChecker.isSubtypeOf(actualType, targetType)) {
context.trace.report(USELESS_CAST_STATIC_ASSERT_IS_FINE.on(expression.getOperationReference()));
}
else {
// See JET-58 Make 'as never succeeds' a warning, or even never check for Java (external) types
context.trace.report(CAST_NEVER_SUCCEEDS.on(expression.getOperationReference()));
}
}
else {
if (typeChecker.isSubtypeOf(actualType, targetType)) {
@@ -239,6 +242,75 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
}
}
// As this method produces a warning, it must be _complete_ (not sound), i.e. every time it says "cast impossible",
// it must be really impossible
public boolean isCastPossible(@NotNull JetType lhsType, @NotNull JetType rhsType) {
if (isRelated(lhsType, rhsType)) return true;
// This is an oversimplification (which does not render the method incomplete):
// we consider any type parameter capable of taking any value, which may be made more precise if we considered bounds
if (isTypeParameter(lhsType) || isTypeParameter(rhsType)) return true;
if (isFinal(lhsType) || isFinal(rhsType)) return false;
if (isTrait(lhsType) || isTrait(rhsType)) return true;
return false;
}
/**
* Two types are related, roughly, when one is a subtype or supertype of the other.
*
* Note that some types have platform-specific counterparts, i.e. jet.String is mapped to java.lang.String,
* such types (and all their sub- and supertypes) are related too.
*
* Due to limitations in PlatformToKotlinClassMap, we only consider mapping of platform classes to Kotlin classed
* (i.e. java.lang.String -> jet.String) and ignore mappings that go the other way.
*/
private boolean isRelated(@NotNull JetType a, @NotNull JetType b) {
List<JetType> aTypes = mapToPlatformIndependentTypes(a);
List<JetType> bTypes = mapToPlatformIndependentTypes(b);
for (int i = 0; i < aTypes.size(); i++) {
JetType aType = aTypes.get(i);
for (int j = 0; j < bTypes.size(); j++) {
JetType bType = bTypes.get(j);
if (JetTypeChecker.INSTANCE.isSubtypeOf(aType, bType)) return true;
if (JetTypeChecker.INSTANCE.isSubtypeOf(bType, aType)) return true;
}
}
return false;
}
private List<JetType> mapToPlatformIndependentTypes(@NotNull JetType type) {
ClassifierDescriptor descriptor = type.getConstructor().getDeclarationDescriptor();
if (!(descriptor instanceof ClassDescriptor)) return Collections.singletonList(type);
ClassDescriptor originalClass = (ClassDescriptor) descriptor;
Collection<ClassDescriptor> kotlinClasses = platformToKotlinClassMap.mapPlatformClass(originalClass);
if (kotlinClasses.isEmpty()) return Collections.singletonList(type);
List<JetType> result = Lists.newArrayListWithCapacity(2);
result.add(type);
for (ClassDescriptor classDescriptor : kotlinClasses) {
JetType kotlinType = TypeUtils.substituteProjectionsForParameters(classDescriptor, type.getArguments());
result.add(kotlinType);
}
return result;
}
private static boolean isTypeParameter(@NotNull JetType type) {
return type.getConstructor().getDeclarationDescriptor() instanceof TypeParameterDescriptor;
}
private static boolean isFinal(@NotNull JetType type) {
return !TypeUtils.canHaveSubtypes(JetTypeChecker.INSTANCE, type);
}
private static boolean isTrait(@NotNull JetType type) {
ClassifierDescriptor descriptor = type.getConstructor().getDeclarationDescriptor();
return descriptor instanceof ClassDescriptor && ((ClassDescriptor) descriptor).getKind() == ClassKind.TRAIT;
}
/**
* Check if assignment from supertype to subtype is erased.
* It is an error in "is" statement and warning in "as".
compiler/testData/diagnostics/tests/cast/neverSucceeds/MappedDirect.kt
+33
View File
@@ -0,0 +1,33 @@
// !DIAGNOSTICS: -WARNING +CAST_NEVER_SUCCEEDS
import java.lang.String as JString
import java.lang.CharSequence as JCS
fun test(
s: String,
js: JString,
cs: CharSequence,
jcs: JCS
) {
s as JString
s as JCS
s as CharSequence
s as String
js as JString
js as JCS
js as CharSequence
js as String
cs as JString
cs as JCS
cs as CharSequence
cs as String
jcs as JString
jcs as JCS
jcs as CharSequence
jcs as String
jcs <!CAST_NEVER_SUCCEEDS!>as<!> Int
s <!CAST_NEVER_SUCCEEDS!>as<!> java.lang.Integer
}
compiler/testData/diagnostics/tests/cast/neverSucceeds/MappedSubtypes.kt
+21
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@@ -0,0 +1,21 @@
// !DIAGNOSTICS: -WARNING +CAST_NEVER_SUCCEEDS -ABSTRACT_MEMBER_NOT_IMPLEMENTED
import java.lang.CharSequence as JCS
class JSub: JCS
class Sub: CharSequence
fun test(
s: Sub,
js: JSub,
cs: CharSequence,
jcs: JCS
) {
// js as CharSequence // - this case is not supported due to limitation in PlatformToKotlinClassMap
js as JCS
s as CharSequence
s as JCS
js <!CAST_NEVER_SUCCEEDS!>as<!> Sub
s <!CAST_NEVER_SUCCEEDS!>as<!> JSub
}
compiler/testData/diagnostics/tests/cast/neverSucceeds/NoGenericsRelated.kt
+46
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@@ -0,0 +1,46 @@
// !DIAGNOSTICS: -WARNING +CAST_NEVER_SUCCEEDS
trait T1
trait T2
trait T3
open class OC1: T1
open class OC2: OC1(), T2
class FC1: OC2(), T3
trait T4: OC1
trait T5: T2
fun test<TP1: OC1, TP2: T2, TP3: OC2>(
t2: T2,
t4: T4,
fc1: FC1,
oc1: OC1,
oc2: OC2,
tp1: TP1,
tp2: TP2
) {
fc1 as FC1
fc1 as OC1
fc1 as T1
fc1 as TP1
oc1 as FC1
oc1 as OC2
oc2 as OC1
oc1 as T2
oc1 as T1
oc1 as TP1
oc1 as TP2
t2 as FC1
t2 as OC2
t4 as OC1
t2 as T2
t2 as T5
t2 as TP2
tp1 as FC1
tp1 as OC1
tp1 as OC2
tp2 as T2
tp2 as T5
tp1 as TP3
}
compiler/testData/diagnostics/tests/cast/neverSucceeds/NoGenericsUnrelated.kt
+34
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@@ -0,0 +1,34 @@
// !DIAGNOSTICS: -WARNING +CAST_NEVER_SUCCEEDS
trait Trait1
trait Trait2
open class OClass1
open class OClass2
class FClass1
class FClass2
fun test<TP1: OClass1, TP2: OClass2>(
t1: Trait1,
oc1: OClass1,
fc1: FClass1,
tp1: TP1
) {
t1 as Trait2
t1 as OClass2
t1 <!CAST_NEVER_SUCCEEDS!>as<!> FClass2
t1 as TP2
oc1 as Trait2
oc1 <!CAST_NEVER_SUCCEEDS!>as<!> OClass2
oc1 <!CAST_NEVER_SUCCEEDS!>as<!> FClass2
oc1 as TP2
fc1 <!CAST_NEVER_SUCCEEDS!>as<!> Trait2
fc1 <!CAST_NEVER_SUCCEEDS!>as<!> OClass2
fc1 <!CAST_NEVER_SUCCEEDS!>as<!> FClass2
fc1 as TP2
tp1 as Trait2
tp1 as OClass2
tp1 as FClass2
tp1 as TP2
}
compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
+36 -1
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@@ -954,6 +954,7 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
}
@TestMetadata("compiler/testData/diagnostics/tests/cast")
@InnerTestClasses({Cast.NeverSucceeds.class})
public static class Cast extends AbstractDiagnosticsTestWithEagerResolve {
public void testAllFilesPresentInCast() throws Exception {
JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.GenerateTests", new File("compiler/testData/diagnostics/tests/cast"), Pattern.compile("^(.+)\\.kt$"), true);
@@ -1064,6 +1065,40 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
doTest("compiler/testData/diagnostics/tests/cast/WhenWithExpression.kt");
}
@TestMetadata("compiler/testData/diagnostics/tests/cast/neverSucceeds")
public static class NeverSucceeds extends AbstractDiagnosticsTestWithEagerResolve {
public void testAllFilesPresentInNeverSucceeds() throws Exception {
JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.GenerateTests", new File("compiler/testData/diagnostics/tests/cast/neverSucceeds"), Pattern.compile("^(.+)\\.kt$"), true);
}
@TestMetadata("MappedDirect.kt")
public void testMappedDirect() throws Exception {
doTest("compiler/testData/diagnostics/tests/cast/neverSucceeds/MappedDirect.kt");
}
@TestMetadata("MappedSubtypes.kt")
public void testMappedSubtypes() throws Exception {
doTest("compiler/testData/diagnostics/tests/cast/neverSucceeds/MappedSubtypes.kt");
}
@TestMetadata("NoGenericsRelated.kt")
public void testNoGenericsRelated() throws Exception {
doTest("compiler/testData/diagnostics/tests/cast/neverSucceeds/NoGenericsRelated.kt");
}
@TestMetadata("NoGenericsUnrelated.kt")
public void testNoGenericsUnrelated() throws Exception {
doTest("compiler/testData/diagnostics/tests/cast/neverSucceeds/NoGenericsUnrelated.kt");
}
}
public static Test innerSuite() {
TestSuite suite = new TestSuite("Cast");
suite.addTestSuite(Cast.class);
suite.addTestSuite(NeverSucceeds.class);
return suite;
}
}
@TestMetadata("compiler/testData/diagnostics/tests/checkArguments")
@@ -5423,7 +5458,7 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
suite.addTestSuite(Annotations.class);
suite.addTestSuite(BackingField.class);
suite.addTestSuite(CallableReference.class);
suite.addTestSuite(Cast.class);
suite.addTest(Cast.innerSuite());
suite.addTestSuite(CheckArguments.class);
suite.addTestSuite(ControlFlowAnalysis.class);
suite.addTestSuite(ControlStructures.class);