[JS IR] Support per-file mode and ES modules

js/js.ast/src/org/jetbrains/kotlin/js/backend/JsToStringGenerationVisitor.java

@@ -1173,6 +1173,69 @@ public class JsToStringGenerationVisitor extends JsVisitor {
         }
     }
 
+    @Override
+    public void visitExport(@NotNull JsExport export) {
+        p.print("export");
+        space();
+        JsExport.Subject subject = export.getSubject();
+
+        if (subject instanceof JsExport.Subject.All) {
+            p.print("*");
+        } else if (subject instanceof JsExport.Subject.Elements) {
+            blockOpen();
+            List<JsExport.Element> elements = ((JsExport.Subject.Elements) subject).getElements();
+            for (JsExport.Element element : elements) {
+                nameDef(element.getName());
+                JsName alias = element.getAlias();
+                if (alias != null) {
+                    p.print(" as ");
+                    nameDef(alias);
+                }
+                p.print(',');
+                p.newline();
+            }
+            p.indentOut();
+            p.print('}');
+        }
+
+        if (export.getFromModule() != null) {
+            p.print(" from ");
+            p.print(javaScriptString(export.getFromModule()));
+        }
+        needSemi = true;
+    }
+
+    @Override
+    public void visitImport(@NotNull JsImport jsImport) {
+        p.print("import {");
+        boolean isMultiline = jsImport.getElements().size() > 1;
+        p.indentIn();
+        if (isMultiline)
+            newlineOpt();
+        else
+            space();
+
+        for (JsImport.Element element : jsImport.getElements()) {
+            nameDef(element.getName());
+            JsName alias = element.getAlias();
+            if (alias != null) {
+                p.print(" as ");
+                nameDef(alias);
+            }
+
+            if (isMultiline) {
+                p.print(',');
+                newlineOpt();
+            } else {
+                space();
+            }
+        }
+        p.indentOut();
+        p.print("} from ");
+        p.print(javaScriptString(jsImport.getModule()));
+    }
+
+
     private void newline() {
         p.newline();
         sourceLocationConsumer.newLine();

js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsExport.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.js.backend.ast
+
+class JsExport(
+    val subject: Subject,
+    val fromModule: String? = null,
+) : SourceInfoAwareJsNode(), JsStatement {
+
+    constructor(element: Element) : this(Subject.Elements(listOf(element)))
+    constructor(name: JsName, alias: JsName? = null) : this(Element(name, alias))
+
+    sealed class Subject {
+        class Elements(val elements: List<Element>) : Subject()
+        object All : Subject()
+    }
+
+    class Element(
+        val name: JsName,
+        val alias: JsName?
+    )
+
+    override fun accept(visitor: JsVisitor) {
+        visitor.visitExport(this)
+    }
+
+    override fun acceptChildren(visitor: JsVisitor) {
+    }
+
+    override fun deepCopy(): JsStatement =
+        JsExport(subject, fromModule)
+
+    override fun traverse(v: JsVisitorWithContext, ctx: JsContext<*>) {
+        v.visit(this, ctx)
+        v.endVisit(this, ctx)
+    }
+}

js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsImport.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.js.backend.ast
+
+class JsImport(
+    val module: String,
+    val elements: MutableList<Element> = mutableListOf(),
+) : SourceInfoAwareJsNode(), JsStatement {
+
+    class Element(
+        val name: JsName,
+        val alias: JsName?
+    ) {
+        constructor(name: String, alias: String?) : this(JsName(name), alias?.let { JsName(it) })
+    }
+
+    override fun accept(visitor: JsVisitor) {
+        visitor.visitImport(this)
+    }
+
+    override fun acceptChildren(visitor: JsVisitor) {
+    }
+
+    override fun deepCopy(): JsStatement =
+        JsImport(module, elements.map { it }.toMutableList())
+
+    override fun traverse(v: JsVisitorWithContext, ctx: JsContext<*>) {
+        v.visit(this, ctx)
+        v.endVisit(this, ctx)
+    }
+}

js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsVisitor.kt

@@ -165,6 +165,12 @@ abstract class JsVisitor {
     open fun visitSingleLineComment(comment: JsSingleLineComment): Unit =
             visitElement(comment)
 
+    open fun visitExport(export: JsExport): Unit =
+            visitElement(export)
+
+    open fun visitImport(import: JsImport): Unit =
+        visitElement(import)
+
     protected open fun visitElement(node: JsNode) {
     }
 }

js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsVisitorWithContext.java

@@ -214,6 +214,12 @@ public abstract class JsVisitorWithContext {
     public void endVisit(@NotNull JsSingleLineComment x, @NotNull JsContext ctx) {
     }
 
+    public void endVisit(@NotNull JsExport x, @NotNull JsContext ctx) {
+    }
+
+    public void endVisit(@NotNull JsImport x, @NotNull JsContext ctx) {
+    }
+
     public void endVisit(@NotNull JsWhile x, @NotNull JsContext ctx) {
         endVisit((JsLoop) x, ctx);
     }
@@ -398,6 +404,14 @@ public abstract class JsVisitorWithContext {
         return true;
     }
 
+    public boolean visit(@NotNull JsExport x, @NotNull JsContext ctx) {
+        return true;
+    }
+
+    public boolean visit(@NotNull JsImport x, @NotNull JsContext ctx) {
+        return true;
+    }
+
     protected abstract  <T extends JsNode> T doAccept(T node);
 
     protected abstract JsExpression doAcceptLvalue(JsExpression expr);