Resolve variables at parse time

docs/modules/style-guide/pages/index.adoc

@@ -193,7 +193,7 @@ Too many lines separate `foo` and `baz`.
 Properties that override an existing property shouldn't have doc comments nor type annotations,
 unless the type is intentionally overridden via `extends`.
 
-[source%tested,{pkl}]
+[source%parsed,{pkl}]
 ----
 amends "myOtherModule.pkl"
 

pkl-core/pkl-core.gradle.kts

@@ -61,6 +61,7 @@ dependencies {
   add("generatorImplementation", libs.javaPoet)
   add("generatorImplementation", libs.truffleApi)
   add("generatorImplementation", libs.jspecify)
+  add("generatorImplementation", projects.pklParser)
 
   javaExecutableConfiguration(project(":pkl-cli", "javaExecutable"))
 }
@@ -140,6 +141,36 @@ tasks.test {
   maxHeapSize = "1g"
 }
 
+val generateBaseModuleMembers by
+  tasks.registering(JavaExec::class) {
+    group = "build"
+
+    val outputDir = layout.buildDirectory.dir("generated/sources/baseModuleMembers")
+
+    val basePklFile = layout.projectDirectory.file("../stdlib/base.pkl")
+
+    inputs
+      .file(basePklFile)
+      .withPropertyName("basePkl")
+      .withPathSensitivity(PathSensitivity.RELATIVE)
+
+    outputs.dir(outputDir)
+
+    classpath =
+      generatorSourceSet.get().runtimeClasspath + tasks.processResources.get().outputs.files
+    mainClass = "org.pkl.core.generator.BaseModuleMembersGenerator"
+
+    argumentProviders.add(
+      CommandLineArgumentProvider {
+        listOf(basePklFile.asFile.absolutePath, outputDir.get().asFile.absolutePath)
+      }
+    )
+  }
+
+sourceSets.main { java.srcDir(layout.buildDirectory.dir("generated/sources/baseModuleMembers")) }
+
+tasks.compileJava { dependsOn(generateBaseModuleMembers) }
+
 val testJavaExecutable by
   tasks.registering(Test::class) {
     configureExecutableTest("LanguageSnippetTestsEngine")

pkl-core/src/generator/java/org/pkl/core/generator/BaseModuleMembersGenerator.java

@@ -0,0 +1,144 @@
+/*
+ * Copyright © 2026 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.pkl.core.generator;
+
+import com.palantir.javapoet.CodeBlock;
+import com.palantir.javapoet.JavaFile;
+import com.palantir.javapoet.MethodSpec;
+import com.palantir.javapoet.TypeName;
+import com.palantir.javapoet.TypeSpec;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import javax.lang.model.element.Modifier;
+import org.pkl.parser.Parser;
+import org.pkl.parser.syntax.Modifier.ModifierValue;
+
+public final class BaseModuleMembersGenerator {
+  record Members(Set<String> properties, Set<String> methods) {}
+
+  public static void main(String[] args) {
+    if (args.length < 2) {
+      throw new IllegalArgumentException(
+          "Usage: BaseModuleMembersGenerator <path-to-base.pkl> <output-dir>");
+    }
+    var members = buildMembers(args[0]);
+    generateJavaCode(members, args[1]);
+  }
+
+  private static void generateJavaCode(Members members, String outputDir) {
+    var privateConstructor = MethodSpec.constructorBuilder().addModifiers(Modifier.PRIVATE).build();
+
+    var hasPropertyMethod =
+        buildHasMethod("hasProperty", members.properties().stream().sorted().toList());
+    var hasMethodMethod = buildHasMethod("hasMethod", members.methods().stream().sorted().toList());
+
+    var classSpec =
+        TypeSpec.classBuilder("BaseModuleMembers")
+            .addModifiers(Modifier.PUBLIC, Modifier.FINAL)
+            .addMethod(privateConstructor)
+            .addMethod(hasPropertyMethod)
+            .addMethod(hasMethodMethod)
+            .build();
+
+    var javaFile =
+        JavaFile.builder("org.pkl.core.runtime", classSpec)
+            .addFileComment("DO NOT EDIT — generated by BaseModuleMembersGenerator")
+            .build();
+
+    try {
+      javaFile.writeTo(Path.of(outputDir));
+    } catch (IOException e) {
+      throw new UncheckedIOException(e);
+    }
+  }
+
+  private static MethodSpec buildHasMethod(String methodName, List<String> names) {
+    var code = CodeBlock.builder();
+    code.add("return switch (name) {\n");
+    code.indent();
+    code.add("case $S", names.get(0));
+    if (names.size() == 1) {
+      code.add(" -> true;\n");
+    } else {
+      code.add(",\n");
+      code.indent();
+      for (var i = 1; i < names.size() - 1; i++) {
+        code.add("$S,\n", names.get(i));
+      }
+      code.add("$S -> true;\n", names.get(names.size() - 1));
+      code.unindent();
+    }
+    code.add("default -> false;\n");
+    code.unindent();
+    code.add("};\n");
+
+    return MethodSpec.methodBuilder(methodName)
+        .addModifiers(Modifier.PUBLIC, Modifier.STATIC)
+        .returns(TypeName.BOOLEAN)
+        .addParameter(String.class, "name")
+        .addCode(code.build())
+        .build();
+  }
+
+  private static String getBaseModuleText(String path) {
+    try {
+      return Files.readString(Path.of(path));
+    } catch (IOException e) {
+      throw new UncheckedIOException(e);
+    }
+  }
+
+  private static Members buildMembers(String basePklPath) {
+    var text = getBaseModuleText(basePklPath);
+    var parsed = new Parser().parseModule(text);
+    var properties = new HashSet<String>();
+    var methods = new HashSet<String>();
+    for (var property : parsed.getProperties()) {
+      if (isLocal(property.getModifiers())) {
+        continue;
+      }
+      properties.add(property.getName().getValue());
+    }
+    for (var clazz : parsed.getClasses()) {
+      if (isLocal(clazz.getModifiers())) {
+        continue;
+      }
+      properties.add(clazz.getName().getValue());
+    }
+    for (var typealias : parsed.getTypeAliases()) {
+      if (isLocal(typealias.getModifiers())) {
+        continue;
+      }
+      properties.add(typealias.getName().getValue());
+    }
+    for (var method : parsed.getMethods()) {
+      if (isLocal(method.getModifiers())) {
+        continue;
+      }
+      methods.add(method.getName().getValue());
+    }
+    return new Members(properties, methods);
+  }
+
+  private static boolean isLocal(List<org.pkl.parser.syntax.Modifier> modifiers) {
+    return modifiers.stream().anyMatch((it) -> it.getValue() == ModifierValue.LOCAL);
+  }
+}

pkl-core/src/main/java/org/pkl/core/ast/VmModifier.java

@@ -55,6 +55,8 @@ private VmModifier() {}
 
   public static final int GLOB = 0x1000;
 
+  public static final int AMBIGUOUS_LOCALITY = 0x10000;
+
   // modifier sets
 
   public static final int NONE = 0;
@@ -126,6 +128,10 @@ public static boolean isConst(int modifiers) {
     return (modifiers & CONST) != 0;
   }
 
+  public static boolean isAmbiguousLocality(int modifiers) {
+    return (modifiers & AMBIGUOUS_LOCALITY) != 0;
+  }
+
   public static boolean isElement(int modifiers) {
     return (modifiers & ELEMENT) != 0;
   }
@@ -154,6 +160,10 @@ public static boolean isConstOrFixed(int modifiers) {
     return (modifiers & (CONST | FIXED)) != 0;
   }
 
+  public static boolean hasSameModifier(int modifiersA, int modifiersB, int modifier) {
+    return (modifiersA & modifier) == (modifiersB & modifier);
+  }
+
   public static Set<Modifier> export(int modifiers, boolean isClass) {
     var result = EnumSet.noneOf(Modifier.class);