check Nothing type for all expressions not only for calls and simple names

(but excluding statement expressions)

compiler/frontend/src/org/jetbrains/jet/lang/cfg/JetControlFlowProcessor.java

@@ -69,14 +69,14 @@ public class JetControlFlowProcessor {
             JetDeclarationWithBody declarationWithBody = (JetDeclarationWithBody) subroutine;
             List<JetParameter> valueParameters = declarationWithBody.getValueParameters();
             for (JetParameter valueParameter : valueParameters) {
-                valueParameter.accept(cfpVisitor);
+                cfpVisitor.generateInstructions(valueParameter);
             }
             JetExpression bodyExpression = declarationWithBody.getBodyExpression();
             if (bodyExpression != null) {
-                bodyExpression.accept(cfpVisitor);
+                cfpVisitor.generateInstructions(bodyExpression);
             }
         } else {
-            subroutine.accept(cfpVisitor);
+            cfpVisitor.generateInstructions(subroutine);
         }
         return builder.exitSubroutine(subroutine);
     }
@@ -115,18 +115,15 @@ public class JetControlFlowProcessor {
                 throw new UnsupportedOperationException("[JetControlFlowProcessor] " + element.toString());
             }
         };
-        private final JetVisitorVoid patternVisitor = new JetVisitorVoid() {
-
-            @Override
-            public void visitJetElement(@NotNull JetElement element) {
-                throw new UnsupportedOperationException("[JetControlFlowProcessor] " + element.toString());
-            }
-        };
 
         private CFPVisitor(boolean inCondition) {
             this.inCondition = inCondition;
         }
 
+        public void generateInstructions(@Nullable JetElement element) {
+            generateInstructions(element, inCondition);
+        }
+
         private void generateInstructions(@Nullable JetElement element, boolean inCondition) {
             if (element == null) return;
             CFPVisitor visitor;
@@ -137,6 +134,22 @@ public class JetControlFlowProcessor {
                 visitor = new CFPVisitor(inCondition);
             }
             element.accept(visitor);
+            checkNothingType(element);
+        }
+
+        private void checkNothingType(JetElement element) {
+            if (!(element instanceof JetExpression)) return;
+            JetExpression expression = JetPsiUtil.deparenthesize((JetExpression) element);
+            if (expression instanceof JetStatementExpression || expression instanceof  JetTryExpression
+                || expression instanceof JetThrowExpression || expression instanceof JetFinallySection
+                    || expression instanceof JetIfExpression || expression instanceof JetWhenExpression) return;
+            //noinspection ConstantConditions
+            if (!trace.get(BindingContext.PROCESSED, expression)) return;
+
+            JetType type = trace.getBindingContext().get(BindingContext.EXPRESSION_TYPE, expression);
+            if (type != null && KotlinBuiltIns.getInstance().isNothing(type)) {
+                builder.jumpToError();
+            }
         }
 
         @Override
@@ -172,12 +185,6 @@ public class JetControlFlowProcessor {
         @Override
         public void visitSimpleNameExpression(@NotNull JetSimpleNameExpression expression) {
             builder.read(expression);
-            if (trace.get(BindingContext.PROCESSED, expression)) {
-                JetType type = trace.getBindingContext().get(BindingContext.EXPRESSION_TYPE, expression);
-                if (type != null && KotlinBuiltIns.getInstance().isNothing(type)) {
-                    builder.jumpToError();
-                }
-            }
         }
 
         @Override
@@ -662,12 +669,6 @@ public class JetControlFlowProcessor {
                 generateInstructions(selectorExpression, false);
             }
             builder.read(expression);
-            if (trace.get(BindingContext.PROCESSED, expression)) {
-                JetType type = trace.getBindingContext().get(BindingContext.EXPRESSION_TYPE, expression);
-                if (type != null && KotlinBuiltIns.getInstance().isNothing(type)) {
-                    builder.jumpToError();
-                }
-            }
         }
 
         private void visitCall(JetCallElement call) {
@@ -693,12 +694,6 @@ public class JetControlFlowProcessor {
 
             generateInstructions(expression.getCalleeExpression(), false);
             builder.read(expression);
-            if (trace.get(BindingContext.PROCESSED, expression)) {
-                JetType type = trace.getBindingContext().get(BindingContext.EXPRESSION_TYPE, expression);
-                if (type != null && KotlinBuiltIns.getInstance().isNothing(type)) {
-                    builder.jumpToError();
-                }
-            }
         }
 
         @Override

compiler/testData/diagnostics/tests/controlFlowAnalysis/DeadCode.kt

@@ -0,0 +1,23 @@
+package c
+
+fun test1() {
+    <!UNREACHABLE_CODE!>val <!UNUSED_VARIABLE!>r<!>: Nothing = null!!<!>
+}
+
+fun test2(a: A) {
+    a + a
+    <!UNREACHABLE_CODE!>bar()<!>
+}
+
+fun test3() {
+    null!!
+    <!UNREACHABLE_CODE!>bar()<!>
+}
+
+fun throwNPE() = null!!
+
+class A {
+    fun plus(<!UNUSED_PARAMETER!>a<!>: A): Nothing = throw Exception()
+}
+
+fun bar() {}

compiler/testData/diagnostics/tests/generics/varProjection/setterProjectedOutAssign.kt

@@ -1,3 +1,5 @@
+// !DIAGNOSTICS: -UNREACHABLE_CODE -UNUSED_PARAMETER
+// t is unused due to KT-4233
 trait Tr<T> {
     var v: T
 }

compiler/testData/diagnostics/tests/generics/varProjection/setterProjectedOutNoPlusAssign.kt

@@ -1,3 +1,4 @@
+// !DIAGNOSTICS: -UNREACHABLE_CODE
 trait Tr<T> {
     var v: T
 }

compiler/testData/diagnostics/tests/generics/varProjection/setterProjectedOutPlusAssignDefined.kt

@@ -1,3 +1,4 @@
+// !DIAGNOSTICS: -UNREACHABLE_CODE
 trait Tr<T> {
     var v: T
 }

compiler/testData/diagnostics/tests/inference/regressions/kt2445.kt

@@ -7,4 +7,5 @@ fun main(args: Array<String>) {
     }
 }
 
-fun test<R>(callback: (R) -> Unit):Unit = callback(null!!)
+// callback is unused due to KT-4233
+fun test<R>(<!UNUSED_PARAMETER!>callback<!>: (R) -> Unit):Unit = <!UNREACHABLE_CODE!>callback(null!!)<!>

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -1402,6 +1402,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 doTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/checkInnerLocalDeclarations.kt");
             }
             
+            @TestMetadata("DeadCode.kt")
+            public void testDeadCode() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/DeadCode.kt");
+            }
+            
             @TestMetadata("kt1001.kt")
             public void testKt1001() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/kt1001.kt");