[java-dfa] Avoid canonicalizing when flushing from LVA

GitOrigin-RevId: f1ba8fc87ede4835e98ed2aceaa792f66a9a529b

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

@@ -144,8 +144,21 @@ public interface DfaMemoryState {
 
   void flushFields();
 
+  /**
+   * Flush given variable (forget any knowledge about it). Equivalent to {@code flushVariable(variable, true)}
+   * @param variable to flush
+   */
   void flushVariable(@NotNull DfaVariableValue variable);
 
+  /**
+   * Flush given variable (forget any knowledge about it)
+   * @param variable to flush
+   * @param canonicalize whether to canonicalize the variable before flushing. Flushing canonical variable allows to forget 
+   *                     about all known aliases as well. Flushing without canonicalization could be necessary only 
+   *                     to simplify memory state, if it's known that given variable is never used anymore.
+   */
+  void flushVariable(@NotNull DfaVariableValue variable, boolean canonicalize);
+
   /**
    * Mark this state as ephemeral. See {@link #isEphemeral()} for details.
    */

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

@@ -1323,11 +1323,16 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
 
   @Override
   public void flushVariable(@NotNull DfaVariableValue variable) {
-    flushVariable(variable, false);
+    flushVariable(variable, true, false);
   }
 
-  protected void flushVariable(@NotNull DfaVariableValue variable, boolean shouldMarkFlushed) {
-    DfaVariableValue canonical = canonicalize(variable);
+  @Override
+  public void flushVariable(@NotNull DfaVariableValue variable, boolean canonicalize) {
+    flushVariable(variable, canonicalize, false);
+  }
+
+  protected void flushVariable(@NotNull DfaVariableValue variable, boolean canonicalize, boolean shouldMarkFlushed) {
+    DfaVariableValue canonical = canonicalize ? canonicalize(variable) : variable;
     EqClass eqClass = canonical.getDependentVariables().isEmpty() ? null : getEqClass(canonical);
     DfaVariableValue newCanonical =
       eqClass == null ? null : StreamEx.of(eqClass.iterator()).without(canonical).min(EqClass.CANONICAL_VARIABLE_COMPARATOR)

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

@@ -131,10 +131,10 @@ final class NullParameterConstraintChecker extends DataFlowRunner {
     }
 
     @Override
-    protected void flushVariable(@NotNull DfaVariableValue variable, boolean shouldMarkFlushed) {
+    protected void flushVariable(@NotNull DfaVariableValue variable, boolean canonicalize, boolean shouldMarkFlushed) {
       final PsiModifierListOwner psi = variable.getPsiVariable();
       if (psi instanceof PsiParameter && myPossiblyViolatedParameters.contains(psi)) return;
-      super.flushVariable(variable, shouldMarkFlushed);
+      super.flushVariable(variable, canonicalize, shouldMarkFlushed);
     }
 
     @NotNull

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/instructions/FinishElementInstruction.java

@@ -26,7 +26,7 @@ public class FinishElementInstruction extends Instruction {
   public DfaInstructionState[] accept(DataFlowRunner runner, DfaMemoryState state, InstructionVisitor visitor) {
     if (!myVarsToFlush.isEmpty()) {
       for (DfaVariableValue value : myVarsToFlush) {
-        state.flushVariable(value);
+        state.flushVariable(value, false);
       }
     }
     return nextInstruction(runner, state);

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

@@ -5,6 +5,19 @@ import java.util.Set;
 import org.jetbrains.annotations.Contract;
 
 public class StringToCharArray {
+  final String field;
+  final int[] bogus = new int[128];
+
+  StringToCharArray(String s) {
+    if (s.isEmpty()) throw new IllegalArgumentException();
+    field = s;
+    char[] chars = field.toCharArray();
+    if (<warning descr="Condition 'chars.length != field.length()' is always 'false'">chars.length != field.length()</warning>) {}
+    if (<warning descr="Condition 's.isEmpty()' is always 'false'">s.isEmpty()</warning>) {
+
+    }
+  }
+
   void test(String s) {
     if (s.startsWith("--")) {
       char[] arr = s.toCharArray();