contract checker: relax fail result validation to accept every call as a potential hazard

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

@@ -17,6 +17,7 @@ package com.intellij.codeInspection.dataFlow;
 
 import com.intellij.codeInspection.dataFlow.instructions.CheckReturnValueInstruction;
 import com.intellij.codeInspection.dataFlow.instructions.Instruction;
+import com.intellij.codeInspection.dataFlow.instructions.MethodCallInstruction;
 import com.intellij.codeInspection.dataFlow.instructions.ReturnInstruction;
 import com.intellij.codeInspection.dataFlow.value.DfaConstValue;
 import com.intellij.codeInspection.dataFlow.value.DfaValue;
@@ -37,6 +38,7 @@ class ContractChecker extends DataFlowRunner {
   private final Set<PsiElement> myViolations = ContainerUtil.newHashSet();
   private final Set<PsiElement> myNonViolations = ContainerUtil.newHashSet();
   private final Set<PsiElement> myFailures = ContainerUtil.newHashSet();
+  private final Set<PsiElement> myCalls = ContainerUtil.newHashSet();
 
   ContractChecker(PsiMethod method, PsiCodeBlock body, MethodContract contract, final boolean onTheFly) {
     super(body);
@@ -102,7 +104,12 @@ class ContractChecker extends DataFlowRunner {
       }
     }
 
-    return super.acceptInstruction(visitor, instructionState);
+    if (instruction instanceof MethodCallInstruction &&
+        ((MethodCallInstruction)instruction).getMethodType() == MethodCallInstruction.MethodType.REGULAR_METHOD_CALL) {
+      ContainerUtil.addIfNotNull(myCalls, ((MethodCallInstruction)instruction).getCallExpression());
+    }
+
+      return super.acceptInstruction(visitor, instructionState);
   }
 
 
@@ -118,7 +125,7 @@ class ContractChecker extends DataFlowRunner {
       for (PsiElement element : myFailures) {
         errors.put(element, "Contract clause '" + myContract + "' is violated: exception might be thrown instead of returning " + myContract.returnValue);
       }
-    } else if (myFailures.isEmpty() && errors.isEmpty()) {
+    } else if (myFailures.isEmpty() && errors.isEmpty() && myCalls.isEmpty()) {
       PsiIdentifier nameIdentifier = myMethod.getNameIdentifier();
       errors.put(nameIdentifier != null ? nameIdentifier : myMethod,
                  "Contract clause '" + myContract + "' is violated: no exception is thrown");

java/java-tests/testData/inspection/dataFlow/contractCheck/NestedCallsMayThrow.java

@@ -0,0 +1,31 @@
+/*
+ * 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.
+ */
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+class Foo {
+
+  @Contract("true->fail")
+  void assertFalse(boolean fail) {
+    if (fail) {
+      failNatively();
+    }
+  }
+  
+  native void failNatively();
+
+}

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

@@ -37,6 +37,7 @@ public class ContractCheckTest extends LightCodeInsightFixtureTestCase {
   public void testEqualsUnknownValue() { doTest(); }
   public void testMissingFail() { doTest(); }
   public void testCheckSuperContract() { doTest(); }
+  public void testNestedCallsMayThrow() { doTest(); }
 
   public void testSignatureIssues() { doTest(); }
 }