Report warning on usages of non-const vals in places where constants expected

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -141,6 +141,8 @@ public interface Errors {
     DiagnosticFactory0<PsiElement> CONST_VAL_WITHOUT_INITIALIZER = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<JetExpression> CONST_VAL_WITH_NON_CONST_INITIALIZER = DiagnosticFactory0.create(ERROR);
 
+    DiagnosticFactory0<JetExpression> NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION = DiagnosticFactory0.create(WARNING);
+
     DiagnosticFactory1<PsiElement, String> INAPPLICABLE_TARGET_ON_PROPERTY = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory0<PsiElement> INAPPLICABLE_FIELD_TARGET_NO_BACKING_FIELD = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<PsiElement> INAPPLICABLE_TARGET_PROPERTY_IMMUTABLE = DiagnosticFactory0.create(ERROR);

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -602,6 +602,7 @@ public class DefaultErrorMessages {
         MAP.put(TYPE_CANT_BE_USED_FOR_CONST_VAL, "Const 'val' has type ''{0}''. Only primitives and String are allowed", RENDER_TYPE);
         MAP.put(CONST_VAL_WITHOUT_INITIALIZER, "Const 'val' should have an initializer");
         MAP.put(CONST_VAL_WITH_NON_CONST_INITIALIZER, "Const 'val' initializer should be a constant value");
+        MAP.put(NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION, "Only 'const val' can be used in constant expressions");
 
         MAP.put(DEFAULT_VALUE_NOT_ALLOWED_IN_OVERRIDE, "An overriding function is not allowed to specify default values for its parameters");
 

compiler/frontend/src/org/jetbrains/kotlin/resolve/DescriptorResolver.java

@@ -39,6 +39,7 @@ import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.psi.*;
 import org.jetbrains.kotlin.psi.psiUtil.PsiUtilPackage;
 import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowInfo;
+import org.jetbrains.kotlin.resolve.constants.CompileTimeConstant;
 import org.jetbrains.kotlin.resolve.constants.ConstantValue;
 import org.jetbrains.kotlin.resolve.constants.evaluate.ConstantExpressionEvaluator;
 import org.jetbrains.kotlin.resolve.dataClassUtils.DataClassUtilsPackage;
@@ -880,7 +881,7 @@ public class DescriptorResolver {
     }
 
     private void setConstantForVariableIfNeeded(
-            @NotNull VariableDescriptorWithInitializerImpl variableDescriptor,
+            @NotNull final VariableDescriptorWithInitializerImpl variableDescriptor,
             @NotNull final LexicalScope scope,
             @NotNull final JetVariableDeclaration variable,
             @NotNull final DataFlowInfo dataFlowInfo,
@@ -898,7 +899,15 @@ public class DescriptorResolver {
                 public ConstantValue<?> invoke() {
                     JetExpression initializer = variable.getInitializer();
                     JetType initializerType = expressionTypingServices.safeGetType(scope, initializer, variableType, dataFlowInfo, trace);
-                    return constantExpressionEvaluator.evaluateToConstantValue(initializer, trace, initializerType);
+                    CompileTimeConstant<?> constant = constantExpressionEvaluator.evaluateExpression(initializer, trace, initializerType);
+
+                    if (constant == null) return null;
+
+                    if (constant.getUsesNonConstValAsConstant() && variableDescriptor.isConst()) {
+                        trace.report(Errors.NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION.on(initializer));
+                    }
+
+                    return constant.toConstantValue(initializerType);
                 }
             }, null)
         );

compiler/frontend/src/org/jetbrains/kotlin/resolve/constants/evaluate/ConstantExpressionEvaluator.kt

@@ -124,6 +124,9 @@ public class ConstantExpressionEvaluator(
 
         val constant = ConstantExpressionEvaluator.getConstant(argumentExpression, trace.getBindingContext())
         if (constant != null && constant.canBeUsedInAnnotations) {
+            if (constant.usesNonConstValAsConstant) {
+                trace.report(Errors.NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION.on(argumentExpression))
+            }
             return
         }
 
@@ -284,7 +287,7 @@ private class ConstantExpressionEvaluatorVisitor(
                            } ?: return null
 
         fun isLongWithSuffix() = nodeElementType == JetNodeTypes.INTEGER_CONSTANT && hasLongSuffix(text)
-        return createConstant(result, expectedType, CompileTimeConstant.Parameters(true, !isLongWithSuffix(), false))
+        return createConstant(result, expectedType, CompileTimeConstant.Parameters(true, !isLongWithSuffix(), false, usesNonConstValAsConstant = false))
     }
 
     override fun visitParenthesizedExpression(expression: JetParenthesizedExpression, expectedType: JetType?): CompileTimeConstant<*>? {
@@ -308,6 +311,7 @@ private class ConstantExpressionEvaluatorVisitor(
         var interupted = false
         var canBeUsedInAnnotation = true
         var usesVariableAsConstant = false
+        var usesNonConstantVariableAsConstant = false
         for (entry in expression.getEntries()) {
             val constant = stringExpressionEvaluator.evaluate(entry)
             if (constant == null) {
@@ -317,6 +321,7 @@ private class ConstantExpressionEvaluatorVisitor(
             else {
                 if (!constant.canBeUsedInAnnotations) canBeUsedInAnnotation = false
                 if (constant.usesVariableAsConstant) usesVariableAsConstant = true
+                if (constant.usesNonConstValAsConstant) usesNonConstantVariableAsConstant = true
                 sb.append(constant.constantValue.value)
             }
         }
@@ -327,7 +332,8 @@ private class ConstantExpressionEvaluatorVisitor(
                     CompileTimeConstant.Parameters(
                             isPure = false,
                             canBeUsedInAnnotation = canBeUsedInAnnotation,
-                            usesVariableAsConstant = usesVariableAsConstant
+                            usesVariableAsConstant = usesVariableAsConstant,
+                            usesNonConstValAsConstant = usesNonConstantVariableAsConstant
                     )
             )
         else null
@@ -363,7 +369,8 @@ private class ConstantExpressionEvaluatorVisitor(
                     CompileTimeConstant.Parameters(
                             canBeUsedInAnnotation = true,
                             isPure = false,
-                            usesVariableAsConstant = leftConstant.usesVariableAsConstant || rightConstant.usesVariableAsConstant
+                            usesVariableAsConstant = leftConstant.usesVariableAsConstant || rightConstant.usesVariableAsConstant,
+                            usesNonConstValAsConstant = leftConstant.usesNonConstValAsConstant || rightConstant.usesNonConstValAsConstant
                     )
             )
         }
@@ -388,6 +395,7 @@ private class ConstantExpressionEvaluatorVisitor(
             val isArgumentPure = isPureConstant(argumentForReceiver.expression)
             val canBeUsedInAnnotation = canBeUsedInAnnotation(argumentForReceiver.expression)
             val usesVariableAsConstant = usesVariableAsConstant(argumentForReceiver.expression)
+            val usesNonConstValAsConstant = usesNonConstValAsConstant(argumentForReceiver.expression)
             val isNumberConversionMethod = resultingDescriptorName in OperatorConventions.NUMBER_CONVERSIONS
             return createConstant(
                     result,
@@ -395,7 +403,7 @@ private class ConstantExpressionEvaluatorVisitor(
                     CompileTimeConstant.Parameters(
                             canBeUsedInAnnotation,
                             !isNumberConversionMethod && isArgumentPure,
-                            usesVariableAsConstant)
+                            usesVariableAsConstant, usesNonConstValAsConstant)
             )
         }
         else if (argumentsEntrySet.size() == 1) {
@@ -415,7 +423,8 @@ private class ConstantExpressionEvaluatorVisitor(
             val areArgumentsPure = isPureConstant(argumentForReceiver.expression) && isPureConstant(argumentForParameter.expression)
             val canBeUsedInAnnotation = canBeUsedInAnnotation(argumentForReceiver.expression) && canBeUsedInAnnotation(argumentForParameter.expression)
             val usesVariableAsConstant = usesVariableAsConstant(argumentForReceiver.expression) || usesVariableAsConstant(argumentForParameter.expression)
-            val parameters = CompileTimeConstant.Parameters(canBeUsedInAnnotation, areArgumentsPure, usesVariableAsConstant)
+            val usesNonConstValAsConstant = usesNonConstValAsConstant(argumentForReceiver.expression) || usesNonConstValAsConstant(argumentForParameter.expression)
+            val parameters = CompileTimeConstant.Parameters(canBeUsedInAnnotation, areArgumentsPure, usesVariableAsConstant, usesNonConstValAsConstant)
             return when (resultingDescriptorName) {
                 OperatorConventions.COMPARE_TO -> createCompileTimeConstantForCompareTo(result, callExpression, factory)?.wrap(parameters)
                 OperatorConventions.EQUALS -> createCompileTimeConstantForEquals(result, callExpression, factory)?.wrap(parameters)
@@ -429,6 +438,8 @@ private class ConstantExpressionEvaluatorVisitor(
     }
 
     private fun usesVariableAsConstant(expression: JetExpression) = ConstantExpressionEvaluator.getConstant(expression, trace.getBindingContext())?.usesVariableAsConstant ?: false
+    private fun usesNonConstValAsConstant(expression: JetExpression)
+            = ConstantExpressionEvaluator.getConstant(expression, trace.bindingContext)?.usesNonConstValAsConstant ?: false
 
     private fun canBeUsedInAnnotation(expression: JetExpression) = ConstantExpressionEvaluator.getConstant(expression, trace.getBindingContext())?.canBeUsedInAnnotations ?: false
 
@@ -515,7 +526,8 @@ private class ConstantExpressionEvaluatorVisitor(
                         CompileTimeConstant.Parameters(
                                 canBeUsedInAnnotation = isPropertyCompileTimeConstant(callableDescriptor),
                                 isPure = false,
-                                usesVariableAsConstant = true
+                                usesVariableAsConstant = true,
+                                usesNonConstValAsConstant = !callableDescriptor.isConst
                         )
                 )
             }
@@ -523,6 +535,7 @@ private class ConstantExpressionEvaluatorVisitor(
         return null
     }
 
+    // TODO: Should be replaced with descriptor.isConst
     private fun isPropertyCompileTimeConstant(descriptor: VariableDescriptor): Boolean {
         if (descriptor.isVar()) {
             return false
@@ -566,7 +579,7 @@ private class ConstantExpressionEvaluatorVisitor(
 
         val resultingDescriptor = call.getResultingDescriptor()
 
-        // array()
+        // arrayOf()
         if (CompileTimeConstantUtils.isArrayMethodCall(call)) {
             val varargType = resultingDescriptor.getValueParameters().first().getVarargElementType()!!
 
@@ -574,7 +587,8 @@ private class ConstantExpressionEvaluatorVisitor(
 
             return factory.createArrayValue(arguments.map { it.toConstantValue(varargType) }, resultingDescriptor.getReturnType()!!).
                     wrap(
-                            usesVariableAsConstant = arguments.any { it.usesVariableAsConstant }
+                            usesVariableAsConstant = arguments.any { it.usesVariableAsConstant },
+                            usesNonConstValAsConstant = arguments.any { it.usesNonConstValAsConstant }
                     )
         }
 
@@ -696,9 +710,10 @@ private class ConstantExpressionEvaluatorVisitor(
     private fun <T> ConstantValue<T>.wrap(
             canBeUsedInAnnotation: Boolean = this !is NullValue,
             isPure: Boolean = false,
-            usesVariableAsConstant: Boolean = false
+            usesVariableAsConstant: Boolean = false,
+            usesNonConstValAsConstant: Boolean = false
     ): TypedCompileTimeConstant<T>
-            = wrap(CompileTimeConstant.Parameters(canBeUsedInAnnotation, isPure, usesVariableAsConstant))
+            = wrap(CompileTimeConstant.Parameters(canBeUsedInAnnotation, isPure, usesVariableAsConstant, usesNonConstValAsConstant))
 }
 
 private fun hasLongSuffix(text: String) = text.endsWith('l') || text.endsWith('L')

compiler/testData/diagnostics/tests/annotations/RecursivelyAnnotatedGlobalProperty.kt

@@ -1,3 +1,3 @@
 // Properties can be recursively annotated
 annotation class ann(val x: Int)
-@ann(x) val x: Int = 1
+@ann(x) const val x: Int = 1

compiler/testData/diagnostics/tests/annotations/RecursivelyAnnotatedGlobalProperty.txt

@@ -1,6 +1,6 @@
 package
 
-@ann(x = 1) public val x: kotlin.Int = 1
+@ann(x = 1) public const val x: kotlin.Int = 1
 
 @kotlin.annotation.annotation() public final class ann : kotlin.Annotation {
     public constructor ann(/*0*/ x: kotlin.Int)

compiler/testData/diagnostics/tests/annotations/annotationParameterMustBeConstant/kotlinProperties.kt

@@ -11,8 +11,8 @@ annotation class Ann(vararg val i: Int)
 class Test
 
 var i1 = 1  // var
-val i2 = 1  // val
+const val i2 = 1  // val
 val i3 = i1 // val with var in initializer
-val i4 = i2 // val with val in initializer
+const val i4 = i2 // val with val in initializer
 var i5 = i1 // var with var in initializer
 var i6 = i2 // var with val in initializer

compiler/testData/diagnostics/tests/annotations/annotationParameterMustBeConstant/kotlinProperties.txt

@@ -1,9 +1,9 @@
 package
 
 public var i1: kotlin.Int
-public val i2: kotlin.Int = 1
+public const val i2: kotlin.Int = 1
 public val i3: kotlin.Int
-public val i4: kotlin.Int = 1
+public const val i4: kotlin.Int = 1
 public var i5: kotlin.Int
 public var i6: kotlin.Int
 

compiler/testData/diagnostics/tests/annotations/annotationParameterMustBeConstant/strings.kt

@@ -1,7 +1,7 @@
 // !DIAGNOSTICS: -UNUSED_VARIABLE
 annotation class Ann(vararg val i: String)
 
-val topLevel = "topLevel"
+const val topLevel = "topLevel"
 
 fun foo() {
     val a1 = "a"

compiler/testData/diagnostics/tests/annotations/annotationParameterMustBeConstant/strings.txt

@@ -1,6 +1,6 @@
 package
 
-public val topLevel: kotlin.String = "topLevel"
+public const val topLevel: kotlin.String = "topLevel"
 public fun foo(): kotlin.Unit
 
 @kotlin.annotation.annotation() public final class Ann : kotlin.Annotation {

compiler/testData/diagnostics/tests/functionAsExpression/Common.kt

@@ -2,7 +2,7 @@
 // !DIAGNOSTICS: -UNUSED_PARAMETER
 
 annotation class ann(val name: String)
-val ok = "OK"
+const val ok = "OK"
 
 class A
 

compiler/testData/diagnostics/tests/functionAsExpression/Common.txt

@@ -2,7 +2,7 @@ package
 
 public val extensionWithoutName: A.() -> kotlin.Unit
 public val funfun: () -> () -> kotlin.Int
-public val ok: kotlin.String = "OK"
+public const val ok: kotlin.String = "OK"
 public val parentesized: () -> kotlin.Unit
 public val parentesizedWithType: () -> kotlin.Unit
 public val withExpression: () -> kotlin.Int

compiler/testData/diagnostics/testsWithStdLib/annotations/annotationParameterMustBeConstant/array.kt

@@ -10,7 +10,7 @@ annotation class Ann(val i: IntArray)
 class Test
 
 var i = 1
-val i2 = 1
+const val i2 = 1
 val i3 = foo()
 
 fun foo(): Int = 1

compiler/testData/diagnostics/testsWithStdLib/annotations/annotationParameterMustBeConstant/array.txt

@@ -1,7 +1,7 @@
 package
 
 public var i: kotlin.Int
-public val i2: kotlin.Int = 1
+public const val i2: kotlin.Int = 1
 public val i3: kotlin.Int
 public val iAnn: Ann
 public fun foo(): kotlin.Int

compiler/testData/diagnostics/testsWithStdLib/annotations/annotationParameterMustBeConstant/useOfNonConstVal.kt

@@ -0,0 +1,16 @@
+val nonConst = 1
+
+const val constConst = <!NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION!>nonConst * nonConst + 2<!>
+
+annotation class Ann(val x: Int, val y: String)
+
+@Ann(<!NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION!>nonConst<!>, <!NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION!>"${nonConst}"<!>)
+fun foo1() {}
+
+@Ann(<!NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION!>nonConst + constConst<!>, "${constConst}")
+fun foo2() {}
+
+annotation class ArrayAnn(val x: IntArray)
+
+@ArrayAnn(<!NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION!>intArrayOf(1, constConst, <!NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION!>nonConst<!>)<!>)
+fun foo3() {}

compiler/testData/diagnostics/testsWithStdLib/annotations/annotationParameterMustBeConstant/useOfNonConstVal.txt

@@ -0,0 +1,24 @@
+package
+
+public const val constConst: kotlin.Int = 3
+public val nonConst: kotlin.Int = 1
+@Ann(x = 1, y = "1") public fun foo1(): kotlin.Unit
+@Ann(x = 4, y = "3") public fun foo2(): kotlin.Unit
+@ArrayAnn(x = {1, 3, 1}) public fun foo3(): kotlin.Unit
+
+@kotlin.annotation.annotation() public final class Ann : kotlin.Annotation {
+    public constructor Ann(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.String)
+    public final val x: kotlin.Int
+    public final val y: kotlin.String
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+@kotlin.annotation.annotation() public final class ArrayAnn : kotlin.Annotation {
+    public constructor ArrayAnn(/*0*/ x: kotlin.IntArray)
+    public final val x: kotlin.IntArray
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/testsWithStdLib/annotations/annotationParameterMustBeConstant/vararg.kt

@@ -13,7 +13,7 @@ annotation class Ann(vararg val i: Int)
 class Test
 
 var i = 1
-val i2 = 1
+const val i2 = 1
 val i3 = foo()
 
 fun foo(): Int = 1

compiler/testData/diagnostics/testsWithStdLib/annotations/annotationParameterMustBeConstant/vararg.txt

@@ -1,7 +1,7 @@
 package
 
 public var i: kotlin.Int
-public val i2: kotlin.Int = 1
+public const val i2: kotlin.Int = 1
 public val i3: kotlin.Int
 public val iAnn: Ann
 public fun foo(): kotlin.Int

compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestWithStdLibGenerated.java

@@ -162,6 +162,12 @@ public class JetDiagnosticsTestWithStdLibGenerated extends AbstractJetDiagnostic
                 doTest(fileName);
             }
 
+            @TestMetadata("useOfNonConstVal.kt")
+            public void testUseOfNonConstVal() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithStdLib/annotations/annotationParameterMustBeConstant/useOfNonConstVal.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("vararg.kt")
             public void testVararg() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithStdLib/annotations/annotationParameterMustBeConstant/vararg.kt");

core/descriptors/src/org/jetbrains/kotlin/resolve/constants/CompileTimeConstant.kt

@@ -34,12 +34,15 @@ public interface CompileTimeConstant<out T> {
 
     public val usesVariableAsConstant: Boolean get() = parameters.usesVariableAsConstant
 
+    public val usesNonConstValAsConstant: Boolean get() = parameters.usesNonConstValAsConstant
+
     public val isPure: Boolean get() = parameters.isPure
 
     public class Parameters(
             public val canBeUsedInAnnotation: Boolean,
             public val isPure: Boolean,
-            public val usesVariableAsConstant: Boolean
+            public val usesVariableAsConstant: Boolean,
+            public val usesNonConstValAsConstant: Boolean
     )
 }
 

idea/testData/checker/AnnotationOnFile.kt

@@ -16,8 +16,8 @@
 
 package boo
 
-val BAZ = "baz"
+const val BAZ = "baz"
-val N = 0
+const val N = 0
 
 @Target(AnnotationTarget.FILE)
 @Retention(AnnotationRetention.SOURCE)