From 6ac3052a65cbb43ff26b5c0d25a08ec9d945f680 Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Mon, 2 Dec 2019 14:25:45 +0700
Subject: [PATCH] CustomMethodHandlers: evaluate enum name()

GitOrigin-RevId: 2172db0a3c0355359d9e0f822409483b8f3c35e7
---
 .../dataFlow/CustomMethodHandlers.java              | 13 +++++++++++++
 .../inspection/dataFlow/fixture/EnumName.java       | 13 +++++++++++++
 .../java/codeInspection/DataFlowInspectionTest.java |  1 +
 3 files changed, 27 insertions(+)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/EnumName.java

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/CustomMethodHandlers.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/CustomMethodHandlers.java
index b0250dc15bae..5ed5c7fe1cef 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/CustomMethodHandlers.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/CustomMethodHandlers.java
@@ -88,6 +88,8 @@ class CustomMethodHandlers {
               (args, memState, factory, method) -> numberAsString(args, memState, factory, 3, Long.SIZE))
     .register(staticCall(JAVA_LANG_LONG, "toBinaryString").parameterCount(1),
               (args, memState, factory, method) -> numberAsString(args, memState, factory, 1, Long.SIZE))
+    .register(instanceCall(JAVA_LANG_ENUM, "name").parameterCount(0),
+              (args, memState, factory, method) -> enumName(args.myQualifier, memState, factory, method.getReturnType()))
     .register(anyOf(
       staticCall(JAVA_UTIL_COLLECTIONS, "emptyList", "emptySet", "emptyMap", "singleton", "singletonList", "singletonMap"),
       staticCall(JAVA_UTIL_LIST, "of"),
@@ -341,6 +343,17 @@ class CustomMethodHandlers {
     return factory.getFactFactory().createValue(map);
   }
 
+  private static DfaValue enumName(DfaValue qualifier, DfaMemoryState state, DfaValueFactory factory, PsiType type) {
+    DfaConstValue constant = state.getConstantValue(qualifier);
+    if (constant != null) {
+      Object value = constant.getValue();
+      if (value instanceof PsiEnumConstant) {
+        return factory.getConstFactory().createFromValue(((PsiEnumConstant)value).getName(), type);
+      }
+    }
+    return null;
+  }
+
   private static Object getConstantValue(DfaMemoryState memoryState, DfaValue value) {
     if (value != null) {
       LongRangeSet fact = memoryState.getValueFact(value, DfaFactType.RANGE);
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/EnumName.java b/java/java-tests/testData/inspection/dataFlow/fixture/EnumName.java
new file mode 100644
index 000000000000..1d29a5987de4
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/EnumName.java
@@ -0,0 +1,13 @@
+enum X {
+  FOO, BAR, BAZ
+}
+
+class C {
+  void test(X x) {
+    if (x == X.FOO) {
+      if (<warning descr="Condition 'x.name().equals(\"FOO\")' is always 'true'">x.name().equals("FOO")</warning>) {
+        
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
index d92181e8fac1..5e98c724e827 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
@@ -671,4 +671,5 @@ public class DataFlowInspectionTest extends DataFlowInspectionTestCase {
   public void testCellsComplex() { doTest(); }
   public void testArraysAsList() { doTest(); }
   public void testArraycopy() { doTest(); }
+  public void testEnumName() { doTest(); }
 }