PY-1209 Unused local variable inspection doesn't handle name conflicts correctly

python/src/com/jetbrains/python/codeInsight/controlflow/PyControlFlowBuilder.java

@@ -560,4 +560,28 @@ public class PyControlFlowBuilder extends PyRecursiveElementVisitor {
     node.acceptChildren(evaluator);
     InstructionBuilder.addAssertInstructions(myBuilder, evaluator);
   }
+
+  @Override
+  public void visitPyLambdaExpression(final PyLambdaExpression node) {
+    myBuilder.startNode(node);
+    for (PyParameter parameter : node.getParameterList().getParameters()){
+      final PyExpression value = parameter.getDefaultValue();
+      if (value != null){
+        value.accept(this);
+      }
+      final PyNamedParameter namedParameter = parameter.getAsNamed();
+      if (namedParameter != null){
+        final PsiElement paramName = namedParameter.getFirstChild();
+        final ReadWriteInstruction instruction = ReadWriteInstruction.newInstruction(myBuilder, paramName,
+                                                                                     parameter.getName(),
+                                                                                     ReadWriteInstruction.ACCESS.WRITE);
+        myBuilder.addNode(instruction);
+        myBuilder.checkPending(instruction);
+      }
+    }
+    final PyExpression body = node.getBody();
+    if (body != null){
+      body.accept(this);
+    }
+  }
 }

python/src/com/jetbrains/python/codeInsight/controlflow/ReadWriteInstruction.java

@@ -2,6 +2,7 @@ package com.jetbrains.python.codeInsight.controlflow;
 
 import com.intellij.codeInsight.controlflow.ControlFlowBuilder;
 import com.intellij.codeInsight.controlflow.impl.InstructionImpl;
+import com.intellij.psi.PsiElement;
 import com.jetbrains.python.psi.PyElement;
 import org.jetbrains.annotations.NonNls;
 
@@ -32,7 +33,7 @@ public class ReadWriteInstruction extends InstructionImpl {
   private final ACCESS myAccess;
 
   private ReadWriteInstruction(final ControlFlowBuilder builder,
-                              final PyElement element,
+                              final PsiElement element,
                               final String name,
                               final ACCESS access) {
     super(builder, element);
@@ -73,7 +74,7 @@ public class ReadWriteInstruction extends InstructionImpl {
   }
 
   public static ReadWriteInstruction newInstruction(final ControlFlowBuilder builder,
-                              final PyElement element,
+                              final PsiElement element,
                               final String name,
                               final ACCESS access) {
     return new ReadWriteInstruction(builder, element, name, access);

python/src/com/jetbrains/python/inspections/PyUnusedLocalVariableInspectionVisitor.java

@@ -200,7 +200,7 @@ class PyUnusedLocalVariableInspectionVisitor extends PyInspectionVisitor {
     // Register problems
     for (PsiElement element : myUnusedElements) {
       final String name = element.getText();
-      if (element instanceof PyNamedParameter) {
+      if (element instanceof PyNamedParameter || element.getParent() instanceof PyNamedParameter) {
         // Ignore unused self parameters as obligatory
         if ("self".equals(name) && PyPsiUtils.isMethodContext(element)) {
           continue;

python/src/com/jetbrains/python/psi/PyLambdaExpression.java

@@ -1,7 +1,11 @@
 package com.jetbrains.python.psi;
 
+import org.jetbrains.annotations.Nullable;
+
 /**
  * @author yole
  */
 public interface PyLambdaExpression extends PyExpression, Callable {
+  @Nullable
+  public PyExpression getBody();
 }

python/src/com/jetbrains/python/psi/impl/PyLambdaExpressionImpl.java

@@ -10,6 +10,7 @@ import com.jetbrains.python.psi.*;
 import com.jetbrains.python.psi.types.PyType;
 import com.jetbrains.python.psi.types.TypeEvalContext;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * @author yole
@@ -33,11 +34,16 @@ public class PyLambdaExpressionImpl extends PyElementImpl implements PyLambdaExp
   }
 
   public PyType getReturnType() {
-    PyExpression body = PsiTreeUtil.getChildOfType(this, PyExpression.class);
+    final PyExpression body = getBody();
     if (body != null) return body.getType(TypeEvalContext.fast()); // or slow?
     else return null;
   }
 
+  @Nullable
+  public PyExpression getBody() {
+    return PsiTreeUtil.getChildOfType(this, PyExpression.class);
+  }
+
   public PyFunction asMethod() {
     return null; // we're never a method
   }

python/testData/codeInsight/controlflow/function.txt

@@ -18,20 +18,22 @@
 17(18) WRITE ACCESS: methodList
 18(19) element: PyAssignmentStatement
 19(20) READ ACCESS: collapse
-20(21) WRITE ACCESS: s
-21(22) READ ACCESS: s
-22(23) WRITE ACCESS: s
-23(24) READ ACCESS: s
-24(25) WRITE ACCESS: processFunc
-25(26) element: PyPrintStatement
-26(27) element: PyListCompExpression
-27(28) READ ACCESS: methodList
-28(29) WRITE ACCESS: method
-29(30) READ ACCESS: method
-30(31) READ ACCESS: spacing
-31(32) READ ACCESS: processFunc
-32(33) READ ACCESS: str
-33(34) READ ACCESS: getattr
-34(35) READ ACCESS: object
-35(36) READ ACCESS: method
-36() element: null
+20(21) element: PyLambdaExpression
+21(22) WRITE ACCESS: s
+22(23) READ ACCESS: s
+23(24) element: PyLambdaExpression
+24(25) WRITE ACCESS: s
+25(26) READ ACCESS: s
+26(27) WRITE ACCESS: processFunc
+27(28) element: PyPrintStatement
+28(29) element: PyListCompExpression
+29(30) READ ACCESS: methodList
+30(31) WRITE ACCESS: method
+31(32) READ ACCESS: method
+32(33) READ ACCESS: spacing
+33(34) READ ACCESS: processFunc
+34(35) READ ACCESS: str
+35(36) READ ACCESS: getattr
+36(37) READ ACCESS: object
+37(38) READ ACCESS: method
+38() element: null

python/testData/codeInsight/controlflow/lambda.py

@@ -0,0 +1 @@
+{(lambda i=i: i) for i in range(4)}

python/testData/codeInsight/controlflow/lambda.txt

@@ -0,0 +1,10 @@
+0(1) element: null
+1(2) element: PyExpressionStatement
+2(3) element: PySetCompExpression
+3(4) READ ACCESS: range
+4(5) WRITE ACCESS: i
+5(6) element: PyLambdaExpression
+6(7) READ ACCESS: i
+7(8) WRITE ACCESS: i
+8(9) READ ACCESS: i
+9() element: null

python/testSrc/com/jetbrains/python/PyControlFlowBuilderTest.java

@@ -135,6 +135,10 @@ public class PyControlFlowBuilderTest extends LightMarkedTestCase {
     doTest();
   }
 
+  public void testLambda() throws Exception {
+    doTest();
+  }
+
   public void testSelf() throws Exception {
     final String testName = getTestName(false).toLowerCase();
     configureByFile(testName + ".py");