Generate Value Classes When on Valhalla (#660)

* write value classes when on valhalla

* Update SimpleAssistWriter.java

* fix assist method inject

* Format only

---------

Co-authored-by: Rob Bygrave <[email protected]>

Author: SentryMan

inject-generator/src/main/java/io/avaje/inject/generator/MetaData.java

@@ -238,7 +238,7 @@ void buildMethod(Append append) {
       appendProvides(append, "autoProvides", autoProvides);
     }
     append.append(")").append(NEWLINE);
-    append.append("  private void build_").append(buildName()).append("() {").append(NEWLINE);
+    append.append("  private void build_").append(buildName()).append("(Builder builder) {").append(NEWLINE);
     if (hasMethod()) {
       append.append("    ").append(Util.shortMethod(method)).append("(builder");
     } else {

inject-generator/src/main/java/io/avaje/inject/generator/SimpleAssistWriter.java

@@ -91,12 +91,23 @@ private void writeClassStart() {
     if (!beanReader.hasTargetFactory()) {
       writer.append("public ");
     }
-    writer.append("final class ").append(name).append(suffix);
+    var valhallaStr = Util.valhalla();
+    if (!valhallaStr.isBlank() && hasAssistedFieldsOrParams()) {
+      valhallaStr = "";
+    }
 
+    writer.append("final %sclass ", valhallaStr).append(name).append(suffix);
     writeImplementsOrExtends();
     writer.append(" {").eol().eol();
   }
 
+  private boolean hasAssistedFieldsOrParams() {
+    return beanReader.injectFields().stream().anyMatch(FieldReader::assisted)
+      || beanReader.injectMethods().stream()
+      .flatMap(m -> m.params().stream())
+      .anyMatch(MethodParam::assisted);
+  }
+
   private void writeImplementsOrExtends() {
     TypeElement targetInterface = beanReader.targetInterface();
     writer

inject-generator/src/main/java/io/avaje/inject/generator/SimpleBeanWriter.java

@@ -333,21 +333,26 @@ private void writeClassEnd() {
   }
 
   private void writeClassStart() {
-    if (beanReader.isRequestScopedController()) {
+    final var requestScopedController = beanReader.isRequestScopedController();
+    if (requestScopedController) {
       writer.append(CODE_COMMENT_FACTORY, shortName).eol();
     } else {
       writer.append(CODE_COMMENT, shortName).eol();
     }
     writer.append(beanReader.generatedType()).append(Constants.AT_GENERATED_COMMENT).eol();
-    if (beanReader.isRequestScopedController()) {
+    if (requestScopedController) {
       writer.append(Constants.AT_SINGLETON).eol();
     }
     String shortName = this.shortName;
     if (beanReader.beanType().getNestingKind().isNested()) {
       shortName = shortName.replace(".", "$");
     }
-    writer.append("public final class ").append(shortName).append(suffix).append(" ");
-    if (beanReader.isRequestScopedController()) {
+    writer
+      .append("public final %sclass ", requestScopedController ? "" : Util.valhalla())
+      .append(shortName)
+      .append(suffix)
+      .append(" ");
+    if (requestScopedController) {
       writer.append("implements ");
       beanReader.factoryInterface(writer);
     }

inject-generator/src/main/java/io/avaje/inject/generator/SimpleModuleWriter.java

@@ -170,12 +170,11 @@ private void writeBuildMethod() {
     if (scopeInfo.addWithBeans()) {
       writeWithBeans();
     }
-    writer.append("    this.builder = builder;").eol();
     writer.append("    // create beans in order based on constructor dependencies").eol();
     writer.append("    // i.e. \"provides\" followed by \"dependsOn\"").eol();
     for (MetaData metaData : ordering.ordered()) {
       if (!metaData.isGenerateProxy()) {
-        writer.append("    build_%s();", metaData.buildName()).eol();
+        writer.append("    build_%s(builder);", metaData.buildName()).eol();
       }
     }
     writer.append("  }").eol();
@@ -219,8 +218,7 @@ private void writeStartClass() {
     scopeInfo.buildAtInjectModule(writer);
 
     String interfaceType = scopeInfo.type().type();
-    writer.append("public final class %s implements %s {", shortName, interfaceType).eol().eol();
-    writer.append("  private Builder builder;").eol().eol();
+    writer.append("public final %sclass %s implements %s {", Util.valhalla(), shortName, interfaceType).eol().eol();
     if (scopeInfo.addModuleConstructor()) {
       writeConstructor();
     }

inject-generator/src/main/java/io/avaje/inject/generator/SimpleOrderWriter.java

@@ -58,7 +58,7 @@ private void writeStartClass() {
         " */\n"
     );
     writer.append(Constants.AT_GENERATED).eol();
-    writer.append("public final class %s implements ModuleOrdering {", shortName).eol().eol();
+    writer.append("public final %sclass %s implements ModuleOrdering {", Util.valhalla(), shortName).eol().eol();
 
     writer.append("  private final AvajeModule[] sortedModules = new AvajeModule[%s];", ordering.size()).eol();
     writer.append("  private static final Map<String, Integer> INDEXES = Map.ofEntries(").eol();

inject-generator/src/main/java/io/avaje/inject/generator/Util.java

@@ -2,6 +2,7 @@
 
 import javax.lang.model.element.AnnotationMirror;
 import javax.lang.model.element.Element;
+import javax.lang.model.element.Modifier;
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.type.TypeKind;
 import javax.lang.model.type.TypeMirror;
@@ -368,4 +369,12 @@ static List<String> addQualifierSuffix(List<String> provides, String name) {
       .collect(toList());
   }
 
+  static String valhalla() {
+    try {
+      if (Modifier.valueOf("VALUE") != null && APContext.previewEnabled()) return "value ";
+    } catch (IllegalArgumentException e) {
+      // no valhalla
+    }
+    return "";
+  }
 }