IDEA-209947 CollectionSizeEquality test, better merge, better presentation of two-element ranges

GitOrigin-RevId: 3e12f5cc9f8eaf828b6ec84a393351b9cad8187e

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

@@ -156,6 +156,11 @@ public class TrackingRunner extends StandardDataFlowRunner {
     CauseItem[] findCauses(TrackingRunner runner, PsiExpression expression, MemoryStateChange history) {
       return new CauseItem[0];
     }
+
+    @Nullable
+    DfaProblemType tryMerge(DfaProblemType other) {
+      return this.toString().equals(other.toString()) ? this : null; 
+    }
   }
 
   public static class CauseItem {
@@ -163,6 +168,12 @@ public class TrackingRunner extends StandardDataFlowRunner {
     final @NotNull DfaProblemType myProblem;
     final @Nullable SmartPsiFileRange myTarget;
 
+    private CauseItem(@NotNull List<CauseItem> children, @NotNull DfaProblemType problem, @Nullable SmartPsiFileRange target) {
+      myChildren = children;
+      myProblem = problem;
+      myTarget = target;
+    }
+    
     CauseItem(@NotNull String problem, @Nullable PsiElement target) {
       this(new CustomDfaProblemType(problem), target);
     }
@@ -270,9 +281,17 @@ public class TrackingRunner extends StandardDataFlowRunner {
 
     public CauseItem merge(CauseItem other) {
       if (this.equals(other)) return this;
-      if (Objects.equals(this.myTarget, other.myTarget) && getProblemName().equals(other.getProblemName())) {
-        if(tryMergeChildren(other.myChildren)) return this;
-        if(other.tryMergeChildren(this.myChildren)) return other;
+      if (Objects.equals(this.myTarget, other.myTarget)) {
+        if (myChildren.equals(other.myChildren)) {
+          DfaProblemType mergedProblem = myProblem.tryMerge(other.myProblem);
+          if (mergedProblem != null) {
+            return new CauseItem(myChildren, mergedProblem, myTarget);
+          }
+        }
+        if (getProblemName().equals(other.getProblemName())) {
+          if (tryMergeChildren(other.myChildren)) return this;
+          if (other.tryMergeChildren(this.myChildren)) return other;
+        }
       }
       return null;
     }
@@ -350,6 +369,35 @@ public class TrackingRunner extends StandardDataFlowRunner {
       return myComplete ? "one of the following happens:" : "an execution might exist where:";
     }
   }
+
+  static class RangeDfaProblemType extends DfaProblemType {
+    final @NotNull String myTemplate;
+    final @NotNull LongRangeSet myRangeSet;
+    final @Nullable PsiPrimitiveType myType;
+
+    RangeDfaProblemType(@NotNull String template, @NotNull LongRangeSet set, @Nullable PsiPrimitiveType type) {
+      myTemplate = template;
+      myRangeSet = set;
+      myType = type;
+    }
+
+    @Nullable
+    @Override
+    DfaProblemType tryMerge(DfaProblemType other) {
+      if (other instanceof RangeDfaProblemType) {
+        RangeDfaProblemType rangeProblem = (RangeDfaProblemType)other;
+        if (myTemplate.equals(rangeProblem.myTemplate) && Objects.equals(myType, rangeProblem.myType)) {
+          return new RangeDfaProblemType(myTemplate, myRangeSet.unite(((RangeDfaProblemType)other).myRangeSet), myType);
+        }
+      }
+      return super.tryMerge(other);
+    }
+
+    @Override
+    public String toString() {
+      return String.format(myTemplate, myRangeSet.getPresentationText(myType));
+    }
+  }
   
 
   public static class ValueDfaProblemType extends DfaProblemType {
@@ -933,7 +981,7 @@ public class TrackingRunner extends StandardDataFlowRunner {
             LongRangeSet result = operandRange.castTo((PsiPrimitiveType)type);
             if (range.equals(result)) {
               CauseItem cause =
-                new CauseItem("result of '(" + type.getCanonicalText() + ")' cast is " + range.getPresentationText(null), expression);
+                new CauseItem(new RangeDfaProblemType("result of '(" + type.getCanonicalText() + ")' cast is %s", range, null), expression);
               if (!operandRange.equals(LongRangeSet.fromType(operand.getType()))) {
                 cause.addChildren(findRangeCause(operandPush, castedValue, operandRange, "cast operand is %s"));
               }
@@ -963,8 +1011,9 @@ public class TrackingRunner extends StandardDataFlowRunner {
             LongRangeSet rightRange = rightSet.getFact(fromType);
             LongRangeSet result = leftRange.binOpFromToken(binOp.getOperationTokenType(), rightRange, isLong);
             if (range.equals(result)) {
-              CauseItem cause = new CauseItem("result of '" + binOp.getOperationSign().getText() +
-                                              "' is " + range.getPresentationText(type), factUse);
+              String sign = binOp.getOperationSign().getText();
+              CauseItem cause = new CauseItem(new RangeDfaProblemType("result of '" + (sign.equals("%")?"%%":sign) + "' is %s", 
+                                                                      range, ObjectUtils.tryCast(type, PsiPrimitiveType.class)), factUse);
               CauseItem leftCause = null, rightCause = null;
               if (!leftRange.equals(fromType)) {
                 leftCause = findRangeCause(leftPush, leftVal, leftRange, "left operand is %s");
@@ -979,8 +1028,8 @@ public class TrackingRunner extends StandardDataFlowRunner {
         }
       }
     }
-    String rangeText = range.getPresentationText(expression != null ? expression.getType() : null);
-    CauseItem item = new CauseItem(String.format(template, rangeText), factUse);
+    PsiPrimitiveType type = expression != null ? ObjectUtils.tryCast(expression.getType(), PsiPrimitiveType.class) : null;
+    CauseItem item = new CauseItem(new RangeDfaProblemType(template, range, type), factUse);
     FactDefinition<LongRangeSet> info = factUse.findFact(value, DfaFactType.RANGE);
     MemoryStateChange factDef = range.equals(info.myFact) ? info.myChange : null;
     if (factDef != null) {

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/rangeSet/LongRangeSet.java

@@ -1258,6 +1258,9 @@ public abstract class LongRangeSet {
           return ">= " + LongRangeSet.formatNumber(myFrom);
         }
       }
+      if (myTo - myFrom == 1) {
+        return myFrom + " or " + myTo;
+      }
       return "in " + toString();
     }
 
@@ -2006,6 +2009,9 @@ public abstract class LongRangeSet {
           return "!= " + diff.min();
         }
       }
+      if (myRanges.length == 4 && myRanges[0] == myRanges[1] && myRanges[2] == myRanges[3]) {
+        return myRanges[0] + " or " + myRanges[2];
+      }
       return "in " + toString();
     }
 

java/java-tests/testData/inspection/dataFlow/tracker/AssignTernaryNumeric.java

@@ -1,10 +1,7 @@
 /*
-Value is always false (foo > 3; line#16)
-  One of the following happens:
-    Left operand is 1 (foo; line#16)
-      'foo' was assigned (=; line#15)
-    or left operand is 2 (foo; line#16)
-      'foo' was assigned (=; line#15)
+Value is always false (foo > 3; line#13)
+  Left operand is 1 or 2 (foo; line#13)
+    'foo' was assigned (=; line#12)
  */
 
 import org.jetbrains.annotations.Nullable;

java/java-tests/testData/inspection/dataFlow/tracker/CollectionSizeEquality.java

@@ -0,0 +1,20 @@
+/*
+Value is always false (l1 == l2; line#16)
+  Values cannot be equal because l1.size != l2.size
+    Left operand is 0 (l1; line#16)
+      Range is known from line #14 (!l1.isEmpty(); line#14)
+    and right operand is in {3..Integer.MAX_VALUE} (l2; line#16)
+      Range is known from line #15 (l2.size() < 3; line#15)
+ */
+
+import java.util.List;
+
+class Test {
+  void test(List<String> l1, List<String> l2) {
+    if (!l1.isEmpty()) return;
+    if (l2.size() < 3) return;
+    if (<selection>l1 == l2</selection>) {
+      
+    }
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTrackerTest.java

@@ -164,4 +164,5 @@ public class DataFlowInspectionTrackerTest extends LightCodeInsightFixtureTestCa
   public void testSimpleContract() { doTest(); }
   public void testSimpleContract2() { doTest(); }
   public void testEqualsContract() { doTest(); }
+  public void testCollectionSizeEquality() { doTest(); }
 }