DataFlowInspection: specific message for ioobe contracts, messages moved to resources

Fixes IDEA-180501 Confusing warning about list get method

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/ContractValue.java

@@ -33,6 +33,13 @@ public abstract class ContractValue {
 
   abstract DfaValue makeDfaValue(DfaValueFactory factory, DfaCallArguments arguments);
 
+  /**
+   * @return true if this contract value represents a bounds-checking condition
+   */
+  boolean isBoundCheckingCondition() {
+    return false;
+  }
+
   public static ContractValue qualifier() {
     return Qualifier.INSTANCE;
   }
@@ -160,6 +167,19 @@ public abstract class ContractValue {
       myRelationType = type;
     }
 
+    @Override
+    boolean isBoundCheckingCondition() {
+      switch (myRelationType) {
+        case LE:
+        case LT:
+        case GE:
+        case GT:
+          return true;
+        default:
+          return false;
+      }
+    }
+
     @Override
     DfaValue makeDfaValue(DfaValueFactory factory, DfaCallArguments arguments) {
       return factory.createCondition(myLeft.makeDfaValue(factory, arguments), myRelationType, myRight.makeDfaValue(factory, arguments));

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DataFlowInspectionBase.java

@@ -393,13 +393,21 @@ public class DataFlowInspectionBase extends AbstractBaseJavaLocalInspectionTool
   private static void reportAlwaysFailingCalls(ProblemsHolder holder,
                                                DataFlowInstructionVisitor visitor,
                                                HashSet<PsiElement> reportedAnchors) {
-    for (PsiCall call : visitor.getAlwaysFailingCalls()) {
-      if (TestUtils.isExceptionExpected(call)) continue;
+    visitor.getAlwaysFailingCalls().forEach((call, contracts) -> {
+      if (TestUtils.isExceptionExpected(call)) return;
       PsiMethod method = call.resolveMethod();
       if (method != null && reportedAnchors.add(call)) {
-        holder.registerProblem(getElementToHighlight(call), "The call to '#ref' always fails, according to its method contracts");
+        holder.registerProblem(getElementToHighlight(call), getContractMessage(contracts));
       }
+    });
+  }
+
+  @NotNull
+  private static String getContractMessage(List<MethodContract> contracts) {
+    if (contracts.stream().allMatch(mc -> mc.getConditions().stream().allMatch(cv -> cv.isBoundCheckingCondition()))) {
+      return InspectionsBundle.message("dataflow.message.contract.fail.index");
     }
+    return InspectionsBundle.message("dataflow.message.contract.fail");
   }
 
   @NotNull private static PsiElement getElementToHighlight(@NotNull PsiCall call) {
@@ -965,8 +973,9 @@ public class DataFlowInspectionBase extends AbstractBaseJavaLocalInspectionTool
       return myOptionalQualifiers;
     }
 
-    Collection<PsiCall> getAlwaysFailingCalls() {
-      return StreamEx.ofKeys(myFailingCalls, v -> v).map(MethodCallInstruction::getCallExpression).toList();
+    Map<PsiCall, List<MethodContract>> getAlwaysFailingCalls() {
+      return StreamEx.ofKeys(myFailingCalls, v -> v)
+        .mapToEntry(MethodCallInstruction::getCallExpression, MethodCallInstruction::getContracts).toMap();
     }
 
     boolean isAlwaysReturnsNotNull(Instruction[] instructions) {

java/java-tests/testData/inspection/dataFlow/fixture/ArrayLength.java

@@ -26,6 +26,6 @@ public final class ArrayLength {
       System.out.println("Impossible");
     }
     Arrays.fill(x, -1);
-    Arrays.<warning descr="The call to 'fill' always fails, according to its method contracts">fill</warning>(x, -1, -1, -1);
+    Arrays.<warning descr="The call to 'fill' always fails as index is out of bounds">fill</warning>(x, -1, -1, -1);
   }
 }

java/java-tests/testData/inspection/dataFlow/fixture/CustomContracts.java

@@ -1,6 +1,6 @@
 public class CustomContracts {
   public void testSubstring(String s) {
-    if (s.<warning descr="The call to 'substring' always fails, according to its method contracts">substring</warning>(-1).length() == 0) {
+    if (s.<warning descr="The call to 'substring' always fails as index is out of bounds">substring</warning>(-1).length() == 0) {
       System.out.println("Oops");
     }
   }

java/java-tests/testData/inspection/dataFlow/fixture/ForEachOverEmptyCollection.java

@@ -46,7 +46,7 @@ public class ForEachOverEmptyCollection {
     }
     if(!hasItem) {
       System.out.println(
-        list.<warning descr="The call to 'get' always fails, according to its method contracts">get</warning>(<warning descr="Condition 'max == null' is always 'true'">max == null</warning> ? 0 : 1));
+        list.<warning descr="The call to 'get' always fails as index is out of bounds">get</warning>(<warning descr="Condition 'max == null' is always 'true'">max == null</warning> ? 0 : 1));
     }
   }
 }

java/java-tests/testData/inspection/dataFlow/fixture/LongRangeKnownMethods.java

@@ -196,13 +196,13 @@ public class LongRangeKnownMethods {
 
   void testEmptyListGet(List<String> list) {
     if (list.isEmpty()) {
-      System.out.println(list.<warning descr="The call to 'get' always fails, according to its method contracts">get</warning>(0));
+      System.out.println(list.<warning descr="The call to 'get' always fails as index is out of bounds">get</warning>(0));
     }
   }
 
   void testBoundError(List<String> list) {
     if (list.size() < 10) {
-      System.out.println(list.<warning descr="The call to 'get' always fails, according to its method contracts">get</warning>(10));
+      System.out.println(list.<warning descr="The call to 'get' always fails as index is out of bounds">get</warning>(10));
     }
   }
 

platform/platform-resources-en/src/messages/InspectionsBundle.properties

@@ -64,6 +64,8 @@ dataflow.message.npe.field.access=Dereference of <code>#ref</code> #loc may prod
 dataflow.message.cce=Casting <code>{0}</code> to <code>#ref</code> #loc may produce <code>java.lang.ClassCastException</code>
 dataflow.message.arraystore=Storing element of type <code>{0}</code> to array of <code>{1}</code> elements may produce <code>java.lang.ArrayStoreException</code>
 dataflow.message.redundant.instanceof=Condition <code>#ref</code> #loc is redundant and can be replaced with <code>!= null</code>
+dataflow.message.contract.fail=The call to '#ref' always fails, according to its method contracts
+dataflow.message.contract.fail.index=The call to '#ref' always fails as index is out of bounds
 dataflow.message.constant.condition=Condition <code>#ref</code> #loc is always <code>{0}</code>
 dataflow.message.constant.condition.when.reached=Condition <code>#ref</code> #loc is always <code>{0}</code> when reached
 dataflow.message.loop.on.empty.array=Array <code>#ref</code> is always empty