[JS IR] Fix kotlin.js.js with complex constant expressions

Use IR interpreter to evaluate complex constexprs

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/JsCodeOutliningLowering.kt

@@ -132,7 +132,7 @@ private class JsCodeOutlineTransformer(
             return null
 
         val jsCodeArg = expression.getValueArgument(0) ?: error("Expected js code string")
-        val jsStatements = translateJsCodeIntoStatementList(jsCodeArg)
+        val jsStatements = translateJsCodeIntoStatementList(jsCodeArg, backendContext.irBuiltIns)
 
         // Collect used Kotlin local variables and parameters.
         val kotlinLocalsUsedInJs = mutableListOf<IrValueDeclaration>()

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrElementToJsExpressionTransformer.kt

@@ -17,7 +17,10 @@ import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.declarations.IrValueDeclaration
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.types.isUnit
-import org.jetbrains.kotlin.ir.util.*
+import org.jetbrains.kotlin.ir.util.isEffectivelyExternal
+import org.jetbrains.kotlin.ir.util.isEnumClass
+import org.jetbrains.kotlin.ir.util.parentAsClass
+import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.js.backend.ast.*
 
 @Suppress("PARAMETER_NAME_CHANGED_ON_OVERRIDE")
@@ -190,7 +193,10 @@ class IrElementToJsExpressionTransformer : BaseIrElementToJsNodeTransformer<JsEx
 
     override fun visitCall(expression: IrCall, context: JsGenerationContext): JsExpression {
         if (context.checkIfJsCode(expression.symbol)) {
-            val statements = translateJsCodeIntoStatementList(expression.getValueArgument(0) ?: error("JsCode is expected"))
+            val statements = translateJsCodeIntoStatementList(
+                expression.getValueArgument(0) ?: error("JsCode is expected"),
+                context.staticContext.backendContext.irBuiltIns
+            )
             if (statements.isEmpty()) return JsPrefixOperation(JsUnaryOperator.VOID, JsIntLiteral(3)) // TODO: report warning or even error
 
             val lastStatement = statements.last()

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrElementToJsStatementTransformer.kt

@@ -11,7 +11,7 @@ import org.jetbrains.kotlin.ir.backend.js.utils.emptyScope
 import org.jetbrains.kotlin.ir.declarations.IrFunction
 import org.jetbrains.kotlin.ir.declarations.IrVariable
 import org.jetbrains.kotlin.ir.expressions.*
-import org.jetbrains.kotlin.ir.types.*
+import org.jetbrains.kotlin.ir.types.isAny
 import org.jetbrains.kotlin.ir.util.constructedClassType
 import org.jetbrains.kotlin.js.backend.ast.*
 
@@ -106,7 +106,10 @@ class IrElementToJsStatementTransformer : BaseIrElementToJsNodeTransformer<JsSta
 
     override fun visitCall(expression: IrCall, data: JsGenerationContext): JsStatement {
         if (data.checkIfJsCode(expression.symbol)) {
-            val statements = translateJsCodeIntoStatementList(expression.getValueArgument(0) ?: error("JsCode is expected"))
+            val statements = translateJsCodeIntoStatementList(
+                expression.getValueArgument(0) ?: error("JsCode is expected"),
+                data.staticContext.backendContext.irBuiltIns
+            )
             return when (statements.size) {
                 0 -> JsEmpty
                 1 -> statements.single()

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/jsCode.kt

@@ -8,9 +8,11 @@ package org.jetbrains.kotlin.ir.backend.js.transformers.irToJs
 import com.google.gwt.dev.js.ThrowExceptionOnErrorReporter
 import com.google.gwt.dev.js.rhino.CodePosition
 import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.expressions.IrConst
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrStringConcatenation
+import org.jetbrains.kotlin.ir.interpreter.IrInterpreter
 import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
 import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
@@ -21,16 +23,26 @@ import org.jetbrains.kotlin.js.backend.ast.JsRootScope
 import org.jetbrains.kotlin.js.backend.ast.JsStatement
 import org.jetbrains.kotlin.js.parser.parseExpressionOrStatement
 
-fun translateJsCodeIntoStatementList(code: IrExpression): List<JsStatement> {
-    // TODO: check non simple compile time constants (expressions)
+fun translateJsCodeIntoStatementList(code: IrExpression, irBuiltIns: IrBuiltIns): List<JsStatement> {
     // TODO: support proper symbol linkage and label clash resolution
 
+    val interpreter by lazy { IrInterpreter(irBuiltIns) }
+
     fun foldString(expression: IrExpression): String {
         val builder = StringBuilder()
         expression.acceptVoid(object : IrElementVisitorVoid {
             override fun visitElement(element: IrElement) =
                 error("Parameter of js function must be compile time String constant, not ${element.render()}")
 
+            override fun visitExpression(expression: IrExpression) {
+                val result = interpreter.interpret(expression)
+                if (result is IrConst<*>) {
+                    result.acceptVoid(this)
+                } else {
+                    error("Couldn't evaluate constant string expression ${expression.render()}")
+                }
+            }
+
             override fun <T> visitConst(expression: IrConst<T>) {
                 builder.append(expression.kind.valueOf(expression))
             }

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/es6/semantics/IrBoxJsES6TestGenerated.java

@@ -5050,6 +5050,11 @@ public class IrBoxJsES6TestGenerated extends AbstractIrBoxJsES6Test {
             runTest("js/js.translator/testData/box/jsCode/codeFromVariable.kt");
         }
 
+        @TestMetadata("constantExpression.kt")
+        public void testConstantExpression() throws Exception {
+            runTest("js/js.translator/testData/box/jsCode/constantExpression.kt");
+        }
+
         @TestMetadata("continue.kt")
         public void testContinue() throws Exception {
             runTest("js/js.translator/testData/box/jsCode/continue.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/semantics/IrBoxJsTestGenerated.java

@@ -5050,6 +5050,11 @@ public class IrBoxJsTestGenerated extends AbstractIrBoxJsTest {
             runTest("js/js.translator/testData/box/jsCode/codeFromVariable.kt");
         }
 
+        @TestMetadata("constantExpression.kt")
+        public void testConstantExpression() throws Exception {
+            runTest("js/js.translator/testData/box/jsCode/constantExpression.kt");
+        }
+
         @TestMetadata("continue.kt")
         public void testContinue() throws Exception {
             runTest("js/js.translator/testData/box/jsCode/continue.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java

@@ -5065,6 +5065,11 @@ public class BoxJsTestGenerated extends AbstractBoxJsTest {
             runTest("js/js.translator/testData/box/jsCode/codeFromVariable.kt");
         }
 
+        @TestMetadata("constantExpression.kt")
+        public void testConstantExpression() throws Exception {
+            runTest("js/js.translator/testData/box/jsCode/constantExpression.kt");
+        }
+
         @TestMetadata("continue.kt")
         public void testContinue() throws Exception {
             runTest("js/js.translator/testData/box/jsCode/continue.kt");

js/js.translator/testData/box/jsCode/constantExpression.kt

@@ -0,0 +1,13 @@
+// EXPECTED_REACHABLE_NODES: 1282
+package foo
+
+const val x = '2'
+const val y = '+'
+const val z = '3'
+
+fun box(): String {
+    if (js(x.toString() + z) !== 23) return "Fail 1"
+    if (js(x.toString() + y + z) !== 5) return "Fail 2"
+
+    return "OK"
+}