Resolve modulepath imports from local file

src/main/kotlin/org/pkl/lsp/VirtualFile.kt

@@ -110,6 +110,8 @@ sealed class BaseFile : VirtualFile, CachedValueDataHolderBase() {
 
   private var readError: Exception? = null
 
+  private val lock = Object()
+
   // If contents have not yet been set, read contents from external source, possibly performing I/O.
   override var contents: String
     get() {
@@ -128,7 +130,7 @@ sealed class BaseFile : VirtualFile, CachedValueDataHolderBase() {
       readError = null
       project.cachedValuesManager.clearCachedValue(this, cacheKey)
     }
-    return project.cachedValuesManager.getCachedValue(this, cacheKey) {
+    return project.cachedValuesManager.getCachedValue(this, cacheKey, lock) {
       CachedValue(CompletableFuture.supplyAsync(::doBuildModule), this)
     }!!
   }
@@ -163,7 +165,7 @@ class FsFile(override val path: Path, override val project: Project) : BaseFile(
 
   override val pklProjectDir: VirtualFile?
     get() =
-      project.cachedValuesManager.getCachedValue(this, "FsFile.getProjectDir($path)") {
+      project.cachedValuesManager.getCachedValue(this, "FsFile.getProjectDir($path)", lock) {
         val dependency = project.pklProjectManager.addedOrRemovedFilesModificationTracker
         var dir = if (Files.isDirectory(path)) this else parent()
         while (dir != null) {
@@ -200,6 +202,8 @@ class FsFile(override val path: Path, override val project: Project) : BaseFile(
   override fun canModify(): Boolean = true
 
   override fun doReadContents(): String = path.readText()
+
+  private val lock = Object()
 }
 
 class StdlibFile(moduleName: String, override val project: Project) : BaseFile() {
@@ -272,6 +276,8 @@ class HttpsFile(override val uri: URI, override val project: Project) : BaseFile
 
 class JarFile(override val path: Path, override val uri: URI, override val project: Project) :
   BaseFile() {
+  private val lock = Object()
+
   override val name: String
     get() = path.name
 
@@ -288,7 +294,7 @@ class JarFile(override val path: Path, override val uri: URI, override val proje
 
   override val `package`: PackageDependency?
     get() =
-      project.cachedValuesManager.getCachedValue(this, "JarFile.package(${uri})") {
+      project.cachedValuesManager.getCachedValue(this, "JarFile.package(${uri})", lock) {
         val jarFile: Path = Path.of(URI(uri.toString().drop(4).substringBefore("!/")))
         val jsonFile =
           jarFile.parent.resolve(jarFile.nameWithoutExtension + ".json")
@@ -308,7 +314,11 @@ class JarFile(override val path: Path, override val uri: URI, override val proje
     project.virtualFileManager.get(this.path.resolve(path))
 
   override fun doReadContents(): String =
-    project.cachedValuesManager.getCachedValue(this, "${javaClass.simpleName}-contents-${uri}") {
+    project.cachedValuesManager.getCachedValue(
+      this,
+      "${javaClass.simpleName}-contents-${uri}",
+      lock,
+    ) {
       CachedValue(path.readText())
     }!!
 

src/main/kotlin/org/pkl/lsp/ast/Member.kt

@@ -203,6 +203,8 @@ class PklObjectBodyImpl(
   override val parent: PklNode,
   override val ctx: Node,
 ) : AbstractPklNode(project, parent, ctx), PklObjectBody {
+  private val lock = Object()
+
   override val parameters: PklParameterList? by lazy {
     children.firstInstanceOf<PklParameterList>()
   }
@@ -220,7 +222,7 @@ class PklObjectBodyImpl(
   }
 
   override fun isConstScope(): Boolean {
-    return project.cachedValuesManager.getCachedValue(this, "isConstScope()") {
+    return project.cachedValuesManager.getCachedValue(this, "isConstScope()", lock) {
       val parentProperty = parentOfTypes(PklProperty::class, PklMethod::class)
       val isConstScope =
         if (parentProperty?.isConst == true) {

src/main/kotlin/org/pkl/lsp/ast/ModuleOrClass.kt

@@ -50,9 +50,11 @@ class PklModuleImpl(override val ctx: Node, override val virtualFile: VirtualFil
     header?.moduleExtendsAmendsClause?.moduleUri
   }
 
+  private val lock = Object()
+
   // This is cached at the VirtualFile level
   override fun supermodule(context: PklProject?): PklModule? =
-    project.cachedValuesManager.getCachedValue(this, "supermodule") {
+    project.cachedValuesManager.getCachedValue(this, "supermodule", lock) {
       val resolved = extendsAmendsUri?.resolve(context)
       CachedValue(resolved, listOfNotNull(this.containingFile, resolved?.containingFile))
     }
@@ -61,6 +63,7 @@ class PklModuleImpl(override val ctx: Node, override val virtualFile: VirtualFil
     project.cachedValuesManager.getCachedValue(
       this,
       "PklModule.cache(${virtualFile.uri}, ${context?.projectDir}}",
+      lock,
     ) {
       val cache = ModuleMemberCache.create(this, context)
       CachedValue(cache, cache.dependencies + project.pklProjectManager.syncTracker)

src/main/kotlin/org/pkl/lsp/ast/PklModuleUri.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 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.
@@ -16,6 +16,7 @@
 package org.pkl.lsp.ast
 
 import io.github.treesitter.jtreesitter.Node
+import java.nio.file.Files
 import java.nio.file.Path
 import org.pkl.lsp.*
 import org.pkl.lsp.FsFile
@@ -40,6 +41,8 @@ class PklModuleUriImpl(project: Project, override val parent: PklNode, override
 
   companion object {
 
+    private val lock = Object()
+
     fun resolve(
       project: Project,
       targetUri: String,
@@ -78,7 +81,8 @@ class PklModuleUriImpl(project: Project, override val parent: PklNode, override
       context: PklProject?,
     ): List<VirtualFile>? =
       element.project.cachedValuesManager.getCachedValue(
-        "PklModuleUri.resolveGlob($targetUriString, $moduleUriString, ${element.containingFile.path}, ${context?.projectDir})"
+        "PklModuleUri.resolveGlob($targetUriString, $moduleUriString, ${element.containingFile.path}, ${context?.projectDir})",
+        lock,
       ) {
         val result =
           doResolveGlob(targetUriString, moduleUriString, element, context)
@@ -122,6 +126,17 @@ class PklModuleUriImpl(project: Project, override val parent: PklNode, override
               ?.resolve(targetUri.fragment)
           vfile?.getModule()?.get()
         }
+        "modulepath" -> {
+          val path = targetUri.path.trimStart('/')
+          val absolutePath =
+            project.settingsManager.settings.pklModulepath
+              .map { it.resolve(path) }
+              .firstOrNull(Files::exists) ?: return null
+          return sourceFile.project.virtualFileManager
+            .get(absolutePath.toUri(), absolutePath)
+            ?.getModule()
+            ?.get()
+        }
         // targetUri is a relative URI
         null -> {
           when {

src/main/kotlin/org/pkl/lsp/services/DiagnosticsManager.kt

@@ -44,6 +44,8 @@ class DiagnosticsManager(project: Project) : Component(project) {
   private val openFiles: MutableMap<URI, Boolean> = ConcurrentHashMap()
   private val downloadPackageTracker = SimpleModificationTracker()
 
+  private val lock = Object()
+
   override fun initialize(): CompletableFuture<*> {
     project.messageBus.subscribe(textDocumentTopic, ::handleTextDocumentEvent)
     project.messageBus.subscribe(projectTopic, ::handleProjectEvent)
@@ -96,7 +98,8 @@ class DiagnosticsManager(project: Project) : Component(project) {
 
   fun getDiagnostics(module: PklModule): List<PklDiagnostic> {
     return project.cachedValuesManager.getCachedValue(
-      "DiagnosticsManager.getDiagnostics(${module.uri})"
+      "DiagnosticsManager.getDiagnostics(${module.uri})",
+      lock,
     ) {
       val holder = DiagnosticsHolder()
       for (analyzer in analyzers) {

src/main/kotlin/org/pkl/lsp/services/PackageManager.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 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.
@@ -47,8 +47,10 @@ sealed interface PackageEvent {
 class PackageManager(project: Project) : Component(project) {
   private fun Path.toVirtualFile(): VirtualFile? = project.virtualFileManager.get(this)
 
+  val lock = Object()
+
   fun getLibraryRoots(dependency: PackageDependency): PackageLibraryRoots? =
-    project.cachedValuesManager.getCachedValue("library-roots-${dependency.packageUri}") {
+    project.cachedValuesManager.getCachedValue("library-roots-${dependency.packageUri}", lock) {
       logger.info("Getting library roots for ${dependency.packageUri}")
       val metadataFile =
         dependency.packageUri.relativeMetadataFiles.firstNotNullOfOrNull {
@@ -92,7 +94,8 @@ class PackageManager(project: Project) : Component(project) {
 
   private fun getPackageMetadata(packageDependency: PackageDependency): PackageMetadata? =
     project.cachedValuesManager.getCachedValue(
-      "PackageManager.getPackageMetadata(${packageDependency.packageUri})"
+      "PackageManager.getPackageMetadata(${packageDependency.packageUri})",
+      lock,
     ) {
       val roots = getLibraryRoots(packageDependency) ?: return@getCachedValue null
       CachedValue(PackageMetadata.load(roots.metadataFile))

src/main/kotlin/org/pkl/lsp/services/SettingsManager.kt

@@ -17,6 +17,7 @@ package org.pkl.lsp.services
 
 import com.google.gson.JsonElement
 import com.google.gson.JsonPrimitive
+import java.nio.file.Files
 import java.nio.file.Path
 import java.util.concurrent.CompletableFuture
 import kotlin.io.path.isExecutable
@@ -25,7 +26,11 @@ import org.eclipse.lsp4j.*
 import org.pkl.lsp.*
 import org.pkl.lsp.messages.ActionableNotification
 
-@Serializable data class WorkspaceSettings(var pklCliPath: Path? = null)
+@Serializable
+data class WorkspaceSettings(
+  var pklCliPath: Path? = null,
+  var pklModulepath: List<Path> = listOf(),
+)
 
 class SettingsManager(project: Project) : Component(project) {
   var settings: WorkspaceSettings = WorkspaceSettings()
@@ -50,27 +55,50 @@ class SettingsManager(project: Project) : Component(project) {
           ConfigurationItem().apply {
             scopeUri = "Pkl"
             section = "pkl.cli.path"
-          }
+          },
+          ConfigurationItem().apply {
+            scopeUri = "Pkl"
+            section = "pkl.modulepath"
+          },
         )
       )
-    return project.languageClient
-      .configuration(params)
-      .thenApply { (cliPath) ->
-        logger.log("Got configuration: $cliPath")
-        cliPath as JsonElement
-        if (cliPath.isJsonNull) {
-          settings.pklCliPath = findPklCliOnPath()
-          return@thenApply
-        }
-        if (!(cliPath is JsonPrimitive && cliPath.isString)) {
-          logger.warn("Got non-string value for configuration: $cliPath")
-          return@thenApply
+    return project.languageClient.configuration(params).thenApply { (cliPath, modulepath) ->
+      logger.log("Got configuration: { cli.path = $cliPath, modulepath = $modulepath }")
+      setCliPath(cliPath as JsonElement)
+      setModulepath(modulepath as JsonElement)
+    }
+  }
+
+  private fun setCliPath(cliPath: JsonElement) {
+    if (cliPath.isJsonNull) {
+      settings.pklCliPath = findPklCliOnPath()
+      return
+    }
+    if (!(cliPath is JsonPrimitive && cliPath.isString)) {
+      logger.warn("Got non-string value for configuration: $cliPath")
+      return
+    }
+    settings.pklCliPath =
+      cliPath.asString.let { if (it.isEmpty()) findPklCliOnPath() else Path.of(it) }
+  }
+
+  private fun setModulepath(modulepath: JsonElement) {
+    if (modulepath.isJsonNull) return
+    if (!modulepath.isJsonArray) {
+      logger.warn("Got non-array value for configuration: $modulepath")
+      return
+    }
+    settings.pklModulepath = buildList {
+      for (path in modulepath.asJsonArray) {
+        if (!(path is JsonPrimitive && path.isString)) {
+          logger.warn("Got non-string value in modulepath: $path")
+          continue
         }
-        settings.pklCliPath =
-          cliPath.asString.let { if (it.isEmpty()) findPklCliOnPath() else Path.of(it) }
+        val entry = Path.of(path.asString)
+        if (Files.exists(entry)) add(entry)
+        else logger.warn("Entry in modulepath does not exist: $entry")
       }
-      .exceptionally { logger.error("Failed to fetch settings: ${it.cause}") }
-      .whenComplete { _, _ -> logger.log("Settings changed to $settings") }
+    }
   }
 
   private fun findPklCliOnPath(): Path? {

src/main/kotlin/org/pkl/lsp/type/ComputeExprType.kt

@@ -33,6 +33,7 @@ fun PklNode?.computeExprType(
       project.cachedValuesManager.getCachedValue(
         containingFile,
         "computeExprType(${System.identityHashCode(this)})",
+        lock = this,
       ) {
         val result = doComputeExprType(base, bindings, context)
         val dependencies = buildList {

src/main/kotlin/org/pkl/lsp/util/CachedValuesManager.kt

@@ -68,16 +68,17 @@ class CachedValuesManager(project: Project) : Component(project), CachedValueDat
   fun <T> getCachedValue(
     holder: CachedValueDataHolder,
     key: String,
+    lock: Any,
     provider: () -> CachedValue<T>?,
   ): T? {
-    synchronized(holder) {
+    synchronized(lock) {
       return getValue<T>(holder, key)?.value
         ?: provider()?.also { storeCachedValue(holder, key, it) }?.value
     }
   }
 
-  fun <T> getCachedValue(key: String, provider: () -> CachedValue<T>?): T? =
-    getCachedValue(this, key, provider)
+  fun <T> getCachedValue(key: String, lock: Any, provider: () -> CachedValue<T>?): T? =
+    getCachedValue(this, key, lock, provider)
 
   fun clearCachedValue(holder: CachedValueDataHolder, key: String) {
     holder.cachedValues.remove(key)