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author | Som Snytt <som.snytt@gmail.com> | 2013-11-20 11:44:13 -0800 |
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committer | Som Snytt <som.snytt@gmail.com> | 2013-12-06 12:48:07 -0800 |
commit | 1d30ea86690db1b3b074190094d1f62d12e4efe1 (patch) | |
tree | d6ee4d131ec26f75083883ad0026e8b0c189aee6 /src/compiler/scala/tools/nsc/plugins/Plugin.scala | |
parent | 7d28c4966e5b32b46fda927f303aea4af20c4517 (diff) | |
download | scala-1d30ea86690db1b3b074190094d1f62d12e4efe1.tar.gz scala-1d30ea86690db1b3b074190094d1f62d12e4efe1.tar.bz2 scala-1d30ea86690db1b3b074190094d1f62d12e4efe1.zip |
SI-4841 Plugins get a class path
Let -Xplugin specify a class path (or multiple of them).
Each entry can be a jar or dir, and the first entry to supply
a plugin descriptor defines the plugin to load.
If no plugin is found on the path, then issue a warning if `-Xdev`.
This honors the legacy silent treatment (which scala-ide tests for).
In the proposed scheme, each plugin gets a class loader so that
plugins are isolated from each other.
Presumably, if compiler plugins were a rich ecosystem, in which
shared dependencies were required in incompatible versions, this
would have become a requirement by now.
(Updated with a `DirectTest` that uses two plugins, but keeping
the following as documentation.)
Partest can't do multiple plugins yet, but this is what it looks like:
```
skalac -Xplugin:sample.jar:useful.jar:util,needful.jar:another.jar:util,needful.jar:util:exploded -Xplugin-require:sample,another,other foo.scala
skalac -Xplugin:sample.jar:useful.jar:util,needful.jar:another.jar:util,needful.jar:util:exploded -Xplugin-require:sample,other -Xplugin-disable:another foo.scala
skalac -Xplugin:sample.jar:useful.jar:util,sample.jar:useful.jar:util -Xplugin-require:sample foo.scala
```
The manual test shows three plugins with various permutations of jars and dirs.
The manual test demonstrates that plugins only see classes on their class path:
```
Initializing test.plugins.SamplePlugin
needful.Needful? Failure(java.lang.ClassNotFoundException: needful.Needful)
useful.Useful? Success(class useful.Useful)
Initializing more.plugins.AnotherPlugin
needful.Needful? Success(class needful.Needful)
useful.Useful? Failure(java.lang.ClassNotFoundException: useful.Useful)
Initializing other.plugins.OtherPlugin
```
Disabling a plugin results in a message instead of silent suppression:
```
Disabling plugin another
```
The duplicate plugin class test must still be honored:
```
Ignoring duplicate plugin sample (test.plugins.SamplePlugin)
Initializing test.plugins.SamplePlugin
needful.Needful? Failure(java.lang.ClassNotFoundException: needful.Needful)
useful.Useful? Success(class useful.Useful)
```
If the path is bad, then missing classes will report which plugin induced
the error:
```
Error: class not found: util/Probe required by test.plugins.SamplePlugin
Error: class not found: util/Probe required by more.plugins.AnotherPlugin
Initializing other.plugins.OtherPlugin
needful.Needful? Success(class needful.Needful)
useful.Useful? Failure(java.lang.ClassNotFoundException: useful.Useful)
error: Missing required plugin: sample
error: Missing required plugin: another
two errors found
```
Diffstat (limited to 'src/compiler/scala/tools/nsc/plugins/Plugin.scala')
-rw-r--r-- | src/compiler/scala/tools/nsc/plugins/Plugin.scala | 93 |
1 files changed, 63 insertions, 30 deletions
diff --git a/src/compiler/scala/tools/nsc/plugins/Plugin.scala b/src/compiler/scala/tools/nsc/plugins/Plugin.scala index d194c095f8..183752d4a2 100644 --- a/src/compiler/scala/tools/nsc/plugins/Plugin.scala +++ b/src/compiler/scala/tools/nsc/plugins/Plugin.scala @@ -12,7 +12,8 @@ import scala.reflect.io.{ Directory, File, Path } import java.io.InputStream import java.util.zip.ZipException -import scala.collection.mutable.ListBuffer +import scala.collection.mutable +import mutable.ListBuffer import scala.util.{ Try, Success, Failure } /** Information about a plugin loaded from a jar file. @@ -99,7 +100,7 @@ object Plugin { private def loadDescriptionFromJar(jarp: Path): Try[PluginDescription] = { // XXX Return to this once we have more ARM support def read(is: Option[InputStream]) = is match { - case None => throw new RuntimeException(s"Missing $PluginXML in $jarp") + case None => throw new PluginLoadException(jarp.path, s"Missing $PluginXML in $jarp") case Some(is) => PluginDescription.fromXML(is) } Try(new Jar(jarp.jfile).withEntryStream(PluginXML)(read)) @@ -113,11 +114,14 @@ object Plugin { /** Use a class loader to load the plugin class. */ def load(classname: String, loader: ClassLoader): Try[AnyClass] = { - Try[AnyClass] { - loader loadClass classname - } recoverWith { - case _: Exception => - Failure(new RuntimeException(s"Warning: class not found: ${classname}")) + import scala.util.control.NonFatal + try { + Success[AnyClass](loader loadClass classname) + } catch { + case NonFatal(e) => + Failure(new PluginLoadException(classname, s"Error: unable to load class: $classname")) + case e: NoClassDefFoundError => + Failure(new PluginLoadException(classname, s"Error: class not found: ${e.getMessage} required by $classname")) } } @@ -128,33 +132,54 @@ object Plugin { * A single classloader is created and used to load all of them. */ def loadAllFrom( - jars: List[Path], + paths: List[List[Path]], dirs: List[Path], ignoring: List[String]): List[Try[AnyClass]] = { - // List[(jar, Success(descriptor))] in dir - def scan(d: Directory) = for { - f <- d.files.toList sortBy (_.name) - if Jar isJarOrZip f - pd = loadDescriptionFromJar(f) - if pd.isSuccess - } yield (f, pd) - // (dir, Try(descriptor)) - def explode(d: Directory) = d -> loadDescriptionFromFile(d / PluginXML) - // (j, Try(descriptor)) - def required(j: Path) = j -> loadDescriptionFromJar(j) - - type Paired = Tuple2[Path, Try[PluginDescription]] - val included: List[Paired] = (dirs flatMap (_ ifDirectory scan)).flatten - val exploded: List[Paired] = jars flatMap (_ ifDirectory explode) - val explicit: List[Paired] = jars flatMap (_ ifFile required) - def ignored(p: Paired) = p match { - case (path, Success(pd)) => ignoring contains pd.name - case _ => false + // List[(jar, Try(descriptor))] in dir + def scan(d: Directory) = + d.files.toList sortBy (_.name) filter (Jar isJarOrZip _) map (j => (j, loadDescriptionFromJar(j))) + + type PDResults = List[Try[(PluginDescription, ScalaClassLoader)]] + + // scan plugin dirs for jars containing plugins, ignoring dirs with none and other jars + val fromDirs: PDResults = dirs filter (_.isDirectory) flatMap { d => + scan(d.toDirectory) collect { + case (j, Success(pd)) => Success((pd, loaderFor(Seq(j)))) + } + } + + // scan jar paths for plugins, taking the first plugin you find. + // a path element can be either a plugin.jar or an exploded dir. + def findDescriptor(ps: List[Path]) = { + def loop(qs: List[Path]): Try[PluginDescription] = qs match { + case Nil => Failure(new MissingPluginException(ps)) + case p :: rest => + if (p.isDirectory) loadDescriptionFromFile(p.toDirectory / PluginXML) + else if (p.isFile) loadDescriptionFromJar(p.toFile) + else loop(rest) + } + loop(ps) + } + val fromPaths: PDResults = paths map (p => (p, findDescriptor(p))) map { + case (p, Success(pd)) => Success((pd, loaderFor(p))) + case (_, Failure(e)) => Failure(e) } - val (locs, pds) = ((explicit ::: exploded ::: included) filterNot ignored).unzip - val loader = loaderFor(locs.distinct) - (pds filter (_.isSuccess) map (_.get.classname)).distinct map (Plugin load (_, loader)) + + val seen = mutable.HashSet[String]() + val enabled = (fromPaths ::: fromDirs) map { + case Success((pd, loader)) if seen(pd.classname) => + // a nod to SI-7494, take the plugin classes distinctly + Failure(new PluginLoadException(pd.name, s"Ignoring duplicate plugin ${pd.name} (${pd.classname})")) + case Success((pd, loader)) if ignoring contains pd.name => + Failure(new PluginLoadException(pd.name, s"Disabling plugin ${pd.name}")) + case Success((pd, loader)) => + seen += pd.classname + Plugin.load(pd.classname, loader) + case Failure(e) => + Failure(e) + } + enabled // distinct and not disabled } /** Instantiate a plugin class, given the class and @@ -164,3 +189,11 @@ object Plugin { (clazz getConstructor classOf[Global] newInstance global).asInstanceOf[Plugin] } } + +class PluginLoadException(val path: String, message: String, cause: Exception) extends Exception(message, cause) { + def this(path: String, message: String) = this(path, message, null) +} + +class MissingPluginException(path: String) extends PluginLoadException(path, s"No plugin in path $path") { + def this(paths: List[Path]) = this(paths mkString File.pathSeparator) +} |