[module-based loader] specify the proper classpath for content modules in module-based loader (IJPL-165692)

When a content module is loaded via module-based loader, it may happen that its JAR cannot be found by the standard relative path (pluginDir/lib/modules/module.name.jar), because, for example, the main plugin JAR is located in a pluginDir/lib/frontend-split subdirectory. It's more reliable to use data from the runtime module repository in such cases.

GitOrigin-RevId: 335849d125241d367758485a033d145f951c240e

platform/bootstrap/src/com/intellij/platform/bootstrap/ModuleBasedPluginXmlPathResolver.kt

@@ -4,6 +4,7 @@ package com.intellij.platform.bootstrap
 import com.intellij.ide.plugins.*
 import com.intellij.platform.runtime.product.IncludedRuntimeModule
 import com.intellij.platform.runtime.repository.RuntimeModuleId
+import java.nio.file.Path
 
 /**
  * Implementation of [PathResolver] which can load module descriptors not only from the main plugin JAR file, unlike [PluginXmlPathResolver]
@@ -44,6 +45,11 @@ internal class ModuleBasedPluginXmlPathResolver(
     return fallbackResolver.resolveModuleFile(readContext = readContext, dataLoader = dataLoader, path = path, readInto = readInto)
   }
 
+  override fun resolveCustomModuleClassesRoots(moduleName: String): List<Path> {
+    val moduleDescriptor = includedModules.find { it.moduleDescriptor.moduleId.stringId == moduleName }?.moduleDescriptor
+    return moduleDescriptor?.resourceRootPaths ?: emptyList()
+  }
+
   override fun loadXIncludeReference(
     readInto: RawPluginDescriptor,
     readContext: ReadModuleContext,

platform/core-impl/src/com/intellij/ide/plugins/PathBasedJdomXIncluder.kt

@@ -4,6 +4,7 @@
 package com.intellij.ide.plugins
 
 import org.jetbrains.annotations.ApiStatus
+import java.nio.file.Path
 
 @ApiStatus.Internal
 interface PathResolver {
@@ -16,4 +17,12 @@ interface PathResolver {
 
   // module in a new file name format must always be resolved
   fun resolveModuleFile(readContext: ReadModuleContext, dataLoader: DataLoader, path: String, readInto: RawPluginDescriptor?): RawPluginDescriptor
+
+  /**
+   * Returns custom classes roots for a content module [moduleName] if any. 
+   * If the module is located in the standard place (lib/modules/module.name.jar) or merged with one of JARs loaded by the main classloader, an empty list is returned. 
+   */
+  fun resolveCustomModuleClassesRoots(moduleName: String): List<Path> {
+    return emptyList()
+  }
 }

platform/core-impl/src/com/intellij/ide/plugins/PluginDescriptorLoader.kt

@@ -230,7 +230,12 @@ fun initMainDescriptorByRaw(
       }
       else {
         val subRaw = pathResolver.resolveModuleFile(context, dataLoader, subDescriptorFile, readInto = null)
-        module.descriptor = descriptor.createSub(subRaw, subDescriptorFile, context, module)
+        val subDescriptor = descriptor.createSub(subRaw, subDescriptorFile, context, module)
+        module.descriptor = subDescriptor
+        val customRoots = pathResolver.resolveCustomModuleClassesRoots(module.name)
+        if (customRoots.isNotEmpty()) {
+          subDescriptor.jarFiles = customRoots
+        }
       }
     }
     else {
@@ -993,7 +998,12 @@ private fun loadModuleDescriptors(
     }
 
     val raw = pathResolver.resolveModuleFile(readContext = context, dataLoader = dataLoader, path = subDescriptorFile, readInto = null)
-    module.descriptor = descriptor.createSub(raw = raw, descriptorPath = subDescriptorFile, context = context, module = module)
+    val subDescriptor = descriptor.createSub(raw = raw, descriptorPath = subDescriptorFile, context = context, module = module)
+    val customModuleClassesRoots = pathResolver.resolveCustomModuleClassesRoots(moduleName)
+    if (customModuleClassesRoots.isNotEmpty()) {
+      subDescriptor.jarFiles = customModuleClassesRoots
+    }
+    module.descriptor = subDescriptor
   }
 }