azalea/kotlin-fork
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Make 'when' on nullable enums exhaustive if 'null' entry is present

Browse Source 
#KT-2902 Fixed
This commit is contained in:
Alexander Udalov
2014-10-16 21:38:13 +04:00
parent 91105b8183
commit fe59dc27b3
9 changed files with 241 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files
compiler/frontend/src/org/jetbrains/jet/lang/cfg/WhenChecker.java
+32 -9
View File
@@ -26,8 +26,10 @@ import org.jetbrains.jet.lang.resolve.BindingContext;
import org.jetbrains.jet.lang.resolve.BindingTrace;
import org.jetbrains.jet.lang.resolve.bindingContextUtil.BindingContextUtilPackage;
import org.jetbrains.jet.lang.types.JetType;
import org.jetbrains.jet.lang.types.TypeUtils;
import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
import static org.jetbrains.jet.lang.resolve.BindingContext.EXPRESSION_TYPE;
import static org.jetbrains.jet.lang.resolve.DescriptorUtils.isEnumEntry;
public final class WhenChecker {
@@ -44,13 +46,11 @@ public final class WhenChecker {
}
public static boolean isWhenByEnum(@NotNull JetWhenExpression expression, @NotNull BindingContext context) {
return getSubjectClassDescriptorIfEnum(expression, context) != null;
return getClassDescriptorOfTypeIfEnum(whenSubjectType(expression, context)) != null;
}
private static ClassDescriptor getSubjectClassDescriptorIfEnum(@NotNull JetWhenExpression expression, @NotNull BindingContext context) {
JetExpression subjectExpression = expression.getSubjectExpression();
if (subjectExpression == null) return null;
JetType type = context.get(BindingContext.EXPRESSION_TYPE, subjectExpression);
@Nullable
private static ClassDescriptor getClassDescriptorOfTypeIfEnum(@Nullable JetType type) {
if (type == null) return null;
DeclarationDescriptor declarationDescriptor = type.getConstructor().getDeclarationDescriptor();
if (!(declarationDescriptor instanceof ClassDescriptor)) return null;
@@ -60,10 +60,17 @@ public final class WhenChecker {
return classDescriptor;
}
private static boolean isWhenExhaustive(@NotNull JetWhenExpression expression, @NotNull BindingTrace trace) {
ClassDescriptor classDescriptor = getSubjectClassDescriptorIfEnum(expression, trace.getBindingContext());
@Nullable
private static JetType whenSubjectType(@NotNull JetWhenExpression expression, @NotNull BindingContext context) {
JetExpression subjectExpression = expression.getSubjectExpression();
return subjectExpression == null ? null : context.get(EXPRESSION_TYPE, subjectExpression);
}
if (classDescriptor == null) return false;
private static boolean isWhenExhaustive(@NotNull JetWhenExpression expression, @NotNull BindingTrace trace) {
JetType type = whenSubjectType(expression, trace.getBindingContext());
ClassDescriptor classDescriptor = getClassDescriptorOfTypeIfEnum(type);
if (type == null || classDescriptor == null) return false;
boolean isExhaust = true;
boolean notEmpty = false;
@@ -75,7 +82,7 @@ public final class WhenChecker {
}
}
}
boolean exhaustive = isExhaust && notEmpty;
boolean exhaustive = isExhaust && notEmpty && (!TypeUtils.isNullableType(type) || containsNullCase(expression, trace));
if (exhaustive) {
trace.record(BindingContext.EXHAUSTIVE_WHEN, expression);
}
@@ -101,6 +108,22 @@ public final class WhenChecker {
return false;
}
private static boolean containsNullCase(@NotNull JetWhenExpression expression, @NotNull BindingTrace trace) {
for (JetWhenEntry entry : expression.getEntries()) {
for (JetWhenCondition condition : entry.getConditions()) {
if (condition instanceof JetWhenConditionWithExpression) {
JetType type = trace.getBindingContext().get(
EXPRESSION_TYPE, ((JetWhenConditionWithExpression) condition).getExpression()
);
if (type != null && KotlinBuiltIns.getInstance().isNothingOrNullableNothing(type)) {
return true;
}
}
}
}
return false;
}
private static boolean isCheckForEnumEntry(
@NotNull JetWhenConditionWithExpression whenExpression,
@NotNull ClassDescriptor enumEntry,