1 files changed, 170 insertions, 0 deletions
diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaExpressionFactory.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaExpressionFactory.java
new file mode 100644
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--- /dev/null
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaExpressionFactory.java
@@ -0,0 +1,170 @@
+/*
+ * Copyright 2000-2014 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.codeInspection.dataFlow.value;
+
+import com.intellij.codeInspection.dataFlow.DfaPsiUtil;
+import com.intellij.codeInspection.dataFlow.Nullness;
+import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.openapi.util.Condition;
+import com.intellij.openapi.util.registry.Registry;
+import com.intellij.psi.*;
+import com.intellij.psi.impl.JavaConstantExpressionEvaluator;
+import com.intellij.psi.util.PropertyUtil;
+import com.intellij.psi.util.PsiUtil;
+import com.intellij.util.containers.ContainerUtil;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Map;
+import java.util.regex.Pattern;
+
+/**
+ * @author peter
+ */
+public class DfaExpressionFactory {
+  private static final Logger LOG = Logger.getInstance("#com.intellij.codeInspection.dataFlow.value.DfaExpressionFactory");
+  private static final Condition<String> FALSE_GETTERS = parseFalseGetters();
+
+  private static Condition<String> parseFalseGetters() {
+    try {
+      final Pattern pattern = Pattern.compile(Registry.stringValue("ide.dfa.getters.with.side.effects"));
+      return new Condition<String>() {
+        @Override
+        public boolean value(String s) {
+          return pattern.matcher(s).matches();
+        }
+      };
+    }
+    catch (Exception e) {
+      LOG.error(e);
+      //noinspection unchecked
+      return Condition.FALSE;
+    }
+  }
+
+  private final DfaValueFactory myFactory;
+  private Map<Integer, PsiVariable> myMockIndices = ContainerUtil.newHashMap();
+
+  public DfaExpressionFactory(DfaValueFactory factory) {
+    myFactory = factory;
+  }
+
+  @Nullable
+  public DfaValue getExpressionDfaValue(@Nullable PsiExpression expression) {
+    if (expression == null) return null;
+
+    if (expression instanceof PsiParenthesizedExpression) {
+      return getExpressionDfaValue(((PsiParenthesizedExpression)expression).getExpression());
+    }
+
+    if (expression instanceof PsiArrayAccessExpression) {
+      PsiExpression arrayExpression = ((PsiArrayAccessExpression)expression).getArrayExpression();
+      DfaValue qualifier = getExpressionDfaValue(arrayExpression);
+      if (qualifier instanceof DfaVariableValue) {
+        PsiVariable indexVar = getArrayIndexVariable(((PsiArrayAccessExpression)expression).getIndexExpression());
+        if (indexVar != null) {
+          return myFactory.getVarFactory().createVariableValue(indexVar, expression.getType(), false, (DfaVariableValue)qualifier);
+        }
+      }
+      return null;
+    }
+
+    if (expression instanceof PsiMethodCallExpression) {
+      return createReferenceValue(((PsiMethodCallExpression)expression).getMethodExpression());
+    }
+
+    if (expression instanceof PsiReferenceExpression) {
+      return createReferenceValue((PsiReferenceExpression)expression);
+    }
+
+    if (expression instanceof PsiLiteralExpression) {
+      return myFactory.createLiteralValue((PsiLiteralExpression)expression);
+    }
+
+    if (expression instanceof PsiNewExpression) {
+      return myFactory.createTypeValue(expression.getType(), Nullness.NOT_NULL);
+    }
+
+    final Object value = JavaConstantExpressionEvaluator.computeConstantExpression(expression, false);
+    PsiType type = expression.getType();
+    if (value != null && type != null) {
+      if (value instanceof String) {
+        return myFactory.createTypeValue(type, Nullness.NOT_NULL); // Non-null string literal.
+      }
+      return myFactory.getConstFactory().createFromValue(value, type, null);
+    }
+
+    return null;
+  }
+
+  private DfaValue createReferenceValue(@NotNull PsiReferenceExpression refExpr) {
+    PsiModifierListOwner var = getAccessedVariableOrGetter(refExpr.resolve());
+    if (var == null) {
+      return null;
+    }
+
+    if (!var.hasModifierProperty(PsiModifier.VOLATILE) && !var.hasModifierProperty(PsiModifier.TRANSIENT)) {
+      if (var instanceof PsiVariable && var.hasModifierProperty(PsiModifier.FINAL)) {
+        DfaValue constValue = myFactory.getConstFactory().create((PsiVariable)var);
+        if (constValue != null) return constValue;
+      }
+
+      if (DfaValueFactory.isEffectivelyUnqualified(refExpr)) {
+        return myFactory.getVarFactory().createVariableValue(var, refExpr.getType(), false, null);
+      }
+
+      DfaValue qualifierValue = getExpressionDfaValue(refExpr.getQualifierExpression());
+      if (qualifierValue instanceof DfaVariableValue) {
+        return myFactory.getVarFactory().createVariableValue(var, refExpr.getType(), false, (DfaVariableValue)qualifierValue);
+      }
+    }
+
+    PsiType type = refExpr.getType();
+    return myFactory.createTypeValue(type, DfaPsiUtil.getElementNullability(type, var));
+  }
+
+  @Nullable
+  private static PsiModifierListOwner getAccessedVariableOrGetter(final PsiElement target) {
+    if (target instanceof PsiVariable) {
+      return (PsiVariable)target;
+    }
+    if (target instanceof PsiMethod) {
+      if (PropertyUtil.isSimplePropertyGetter((PsiMethod)target)) {
+        String qName = PsiUtil.getMemberQualifiedName((PsiMethod)target);
+        if (qName == null || !FALSE_GETTERS.value(qName)) {
+          return (PsiMethod)target;
+        }
+      }
+    }
+    return null;
+  }
+
+  @Nullable
+  private PsiVariable getArrayIndexVariable(@Nullable PsiExpression indexExpression) {
+    Object constant = JavaConstantExpressionEvaluator.computeConstantExpression(indexExpression, false);
+    if (constant instanceof Integer) {
+      PsiVariable mockVar = myMockIndices.get(constant);
+      if (mockVar == null) {
+        mockVar = JavaPsiFacade.getElementFactory(indexExpression.getProject()).createField("$array$index$" + constant, PsiType.INT);
+        myMockIndices.put((Integer)constant, mockVar);
+      }
+      return mockVar;
+    }
+    return null;
+  }
+
+
+}