KT-3181 Prohibit val/var keywords for function parameters

#KT-3181

compiler/frontend/src/jet/Arrays.jet

@@ -1,6 +1,6 @@
 package jet
 
-public fun arrayOfNulls<T>(public val size : Int) : Array<T?>
+public fun arrayOfNulls<T>(public size : Int) : Array<T?>
 
 public class Array<reified T>(public val size : Int, init : (Int) -> T) {
   public fun get(index : Int) : T

compiler/frontend/src/jet/Numbers.jet

@@ -87,7 +87,7 @@ public class Double : Number, Comparable<Double>  {
   public override fun toByte() : Byte
 
   public override fun hashCode() : Int
-  public override fun equals(val other : Any?) : Boolean
+  public override fun equals(other : Any?) : Boolean
 }
 
 public class Float : Number, Comparable<Float>  {
@@ -161,7 +161,7 @@ public class Float : Number, Comparable<Float>  {
   public override fun toByte() : Byte
 
   public override fun hashCode() : Int
-  public override fun equals(val other : Any?) : Boolean
+  public override fun equals(other : Any?) : Boolean
 }
 
 public class Long : Number, Comparable<Long> {
@@ -243,7 +243,7 @@ public class Long : Number, Comparable<Long> {
   public override fun toByte() : Byte
 
   public override fun hashCode() : Int
-  public override fun equals(val other : Any?) : Boolean
+  public override fun equals(other : Any?) : Boolean
 }
 
 public class Int : Number, Comparable<Int> {
@@ -325,7 +325,7 @@ public class Int : Number, Comparable<Int> {
   public override fun toByte() : Byte
 
   public override fun hashCode() : Int
-  public override fun equals(val other : Any?) : Boolean
+  public override fun equals(other : Any?) : Boolean
 }
 
 public class Char : Number, Comparable<Char> {
@@ -393,7 +393,7 @@ public class Char : Number, Comparable<Char> {
   public override fun toByte() : Byte
 
   public override fun hashCode() : Int
-  public override fun equals(val other : Any?) : Boolean
+  public override fun equals(other : Any?) : Boolean
 }
 
 public class Short : Number, Comparable<Short> {
@@ -467,7 +467,7 @@ public class Short : Number, Comparable<Short> {
   public override fun toByte() : Byte
 
   public override fun hashCode() : Int
-  public override fun equals(val other : Any?) : Boolean
+  public override fun equals(other : Any?) : Boolean
 }
 
 public class Byte : Number, Comparable<Byte> {
@@ -541,5 +541,5 @@ public class Byte : Number, Comparable<Byte> {
   public override fun toByte() : Byte
 
   public override fun hashCode() : Int
-  public override fun equals(val other : Any?) : Boolean
+  public override fun equals(other : Any?) : Boolean
 }

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/Errors.java

@@ -474,6 +474,7 @@ public interface Errors {
     DiagnosticFactory3<JetExpression, DeclarationDescriptor, Visibility, DeclarationDescriptor> INVISIBLE_SETTER = DiagnosticFactory3.create(ERROR);
 
     DiagnosticFactory1<PsiElement, JetKeywordToken> VAL_OR_VAR_ON_LOOP_PARAMETER = DiagnosticFactory1.create(ERROR);
+    DiagnosticFactory1<PsiElement, JetKeywordToken> VAL_OR_VAR_ON_FUN_PARAMETER = DiagnosticFactory1.create(ERROR);
 
     // Backing fields
 

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/DefaultErrorMessages.java

@@ -180,6 +180,7 @@ public class DefaultErrorMessages {
         MAP.put(VARIABLE_EXPECTED, "Variable expected");
 
         MAP.put(VAL_OR_VAR_ON_LOOP_PARAMETER, "''{0}'' on loop parameter is not allowed", TO_STRING);
+        MAP.put(VAL_OR_VAR_ON_FUN_PARAMETER, "''{0}'' on function parameter is not allowed", TO_STRING);
 
         MAP.put(INITIALIZATION_USING_BACKING_FIELD_CUSTOM_SETTER,
                 "This property has a custom setter, so initialization using backing field required", NAME);

compiler/frontend/src/org/jetbrains/jet/lang/resolve/DescriptorResolver.java

@@ -38,6 +38,7 @@ import org.jetbrains.jet.lang.types.*;
 import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
 import org.jetbrains.jet.lang.types.expressions.ExpressionTypingServices;
 import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
+import org.jetbrains.jet.lexer.JetKeywordToken;
 import org.jetbrains.jet.lexer.JetTokens;
 import org.jetbrains.jet.util.lazy.RecursionIntolerantLazyValue;
 import org.jetbrains.jet.util.lazy.RecursionIntolerantLazyValueWithDefault;
@@ -440,7 +441,7 @@ public class DescriptorResolver {
             BindingTrace trace
     ) {
         List<ValueParameterDescriptor> result = new ArrayList<ValueParameterDescriptor>();
-        for (int i = 0, valueParametersSize = valueParameters.size(); i < valueParametersSize; i++) {
+        for (int i = 0; i < valueParameters.size(); i++) {
             JetParameter valueParameter = valueParameters.get(i);
             JetTypeReference typeReference = valueParameter.getTypeReference();
 
@@ -453,6 +454,13 @@ public class DescriptorResolver {
                 type = typeResolver.resolveType(parameterScope, typeReference, trace, true);
             }
 
+            if (!(functionDescriptor instanceof ConstructorDescriptor)) {
+                ASTNode valOrVarNode = valueParameter.getValOrVarNode();
+                if (valOrVarNode != null) {
+                    trace.report(VAL_OR_VAR_ON_FUN_PARAMETER.on(valOrVarNode.getPsi(), ((JetKeywordToken) valOrVarNode.getElementType())));
+                }
+            }
+
             ValueParameterDescriptor valueParameterDescriptor =
                     resolveValueParameterDescriptor(parameterScope, functionDescriptor, valueParameter, i, type, trace);
             parameterScope.addVariableDescriptor(valueParameterDescriptor);
@@ -477,7 +485,7 @@ public class DescriptorResolver {
                 index,
                 annotationResolver.resolveAnnotations(scope, valueParameter.getModifierList(), trace),
                 JetPsiUtil.safeName(valueParameter.getName()),
-                valueParameter.isMutable(),
+                false,
                 variableType,
                 valueParameter.getDefaultValue() != null,
                 varargElementType

compiler/testData/diagnostics/tests/declarationChecks/valVarFunctionParameter.kt

@@ -0,0 +1,12 @@
+fun f(
+        <!VAL_OR_VAR_ON_FUN_PARAMETER!>val<!> a: Int,
+        <!VAL_OR_VAR_ON_FUN_PARAMETER!>var<!> b: Int,
+        c: Int,
+        vararg <!VAL_OR_VAR_ON_FUN_PARAMETER!>var<!> d: Int,
+        vararg <!VAL_OR_VAR_ON_FUN_PARAMETER!>val<!> e: Int,
+        vararg f: Int
+) {
+    
+    
+    a + b + c + d[0] + e[0] + f[0] // to avoid 'unused parameter'
+}

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

@@ -1543,6 +1543,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 doTest("compiler/testData/diagnostics/tests/declarationChecks/RedeclarationsInMultiDecl.kt");
             }
             
+            @TestMetadata("valVarFunctionParameter.kt")
+            public void testValVarFunctionParameter() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/declarationChecks/valVarFunctionParameter.kt");
+            }
+            
             @TestMetadata("VarianceOnFunctionAndPropertyTypeParameters.kt")
             public void testVarianceOnFunctionAndPropertyTypeParameters() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/declarationChecks/VarianceOnFunctionAndPropertyTypeParameters.kt");