Support src filter in -WConf (Closes #18782)

Author: povder

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -247,6 +247,9 @@ private sealed trait WarningSettings:
          |  - Message name: name=PureExpressionInStatementPosition
          |    The message name is printed with the warning in verbose warning mode.
          |
+         |  - Source location: src=regex
+         |    The regex is evaluated against the full source path.
+         |
          |In verbose warning mode the compiler prints matching filters for warnings.
          |Verbose mode can be enabled globally using `-Wconf:any:verbose`, or locally
          |using the @nowarn annotation (example: `@nowarn("v") def test = try 1`).
@@ -266,6 +269,7 @@ private sealed trait WarningSettings:
          |Examples:
          |  - change every warning into an error: -Wconf:any:error
          |  - silence deprecations: -Wconf:cat=deprecation:s
+         |  - silence warnings in src_managed directory: -Wconf:src=src_managed/.*
          |
          |Note: on the command-line you might need to quote configurations containing `*` or `&`
          |to prevent the shell from expanding patterns.""".stripMargin,

compiler/src/dotty/tools/dotc/reporting/WConf.scala

@@ -5,13 +5,20 @@ package reporting
 import scala.language.unsafeNulls
 
 import dotty.tools.dotc.core.Contexts._
-import dotty.tools.dotc.util.SourcePosition
+import dotty.tools.dotc.util.{NoSourcePosition, SourcePosition}
+import dotty.tools.dotc.interfaces.SourceFile
+import dotty.tools.dotc.reporting.MessageFilter.SourcePattern
 
 import java.util.regex.PatternSyntaxException
 import scala.annotation.internal.sharable
 import scala.util.matching.Regex
+import scala.jdk.OptionConverters._
+import scala.collection.mutable
 
 enum MessageFilter:
+
+  private val sourcePatternCache = mutable.Map.empty[SourceFile, Boolean]
+
   def matches(message: Diagnostic): Boolean = this match
     case Any => true
     case Deprecated => message.isInstanceOf[Diagnostic.DeprecationWarning]
@@ -21,11 +28,21 @@ enum MessageFilter:
       val noHighlight = message.msg.message.replaceAll("\\e\\[[\\d;]*[^\\d;]","")
       pattern.findFirstIn(noHighlight).nonEmpty
     case MessageID(errorId) => message.msg.errorId == errorId
+    case SourcePattern(pattern) =>
+      val source = message.position.orElse(NoSourcePosition).source()
+      sourcePatternCache.getOrElseUpdate(source, {
+        val path = source.jfile()
+          .map(_.toPath.toAbsolutePath.toUri.normalize().getRawPath)
+          .orElse(source.path())
+        pattern.findFirstIn(path).nonEmpty
+      })
+
     case None => false
 
   case Any, Deprecated, Feature, Unchecked, None
   case MessagePattern(pattern: Regex)
   case MessageID(errorId: ErrorMessageID)
+  case SourcePattern(pattern: Regex)
 
 enum Action:
   case Error, Warning, Verbose, Info, Silent
@@ -84,6 +101,9 @@ object WConf:
         case "feature"     => Right(Feature)
         case "unchecked"   => Right(Unchecked)
         case _             => Left(s"unknown category: $conf")
+
+      case "src" => regex(conf).map(SourcePattern.apply)
+
       case _ => Left(s"unknown filter: $filter")
     case _ => Left(s"unknown filter: $s")
 

compiler/test/dotty/tools/dotc/config/ScalaSettingsTests.scala

@@ -7,6 +7,11 @@ import Settings._
 import org.junit.Test
 import org.junit.Assert._
 import core.Decorators.toMessage
+import dotty.tools.io.{Path, PlainFile}
+
+import java.net.URI
+import java.nio.file.Files
+import scala.util.Using
 
 class ScalaSettingsTests:
 
@@ -96,5 +101,61 @@ class ScalaSettingsTests:
     assertEquals(Action.Silent, sut.action(depr))
 
 
+  private def wconfSrcFilterTest(argsStr: String, source: util.SourceFile, expectedAction: reporting.Action): Unit =
+    import reporting.Diagnostic
+    val settings = new ScalaSettings
+    val args = ArgsSummary(settings.defaultState, List(argsStr), errors = Nil, warnings = Nil)
+    val proc = settings.processArguments(args, processAll = true, skipped = Nil)
+    val wconfStr = settings.Wconf.valueIn(proc.sstate)
+    val warning = new Diagnostic.Warning(
+      "A warning".toMessage,
+      util.SourcePosition(
+        source = source,
+        span = util.Spans.Span(1L)
+      )
+    )
+    val wconf = reporting.WConf.fromSettings(wconfStr)
+    assertEquals(Right(expectedAction), wconf.map(_.action(warning)))
+
+  @Test def `WConf src filter silences warnings from a matching path for virtual file`: Unit =
+    wconfSrcFilterTest(
+      argsStr = "-Wconf:src=path/.*:s",
+      source = util.SourceFile.virtual(new URI("file:///some/path/file.scala"), ""),
+      expectedAction = reporting.Action.Silent
+    )
+
+  @Test def `WConf src filter doesn't silence warnings from a non-matching path`: Unit =
+    wconfSrcFilterTest(
+      argsStr = "-Wconf:src=another/.*:s",
+      source = util.SourceFile.virtual(new URI("file:///some/path/file.scala"), ""),
+      expectedAction = reporting.Action.Warning
+    )
+
+  @Test def `WConf src filter silences warnings from a matching path for real file`: Unit =
+    Using.resource(Files.createTempFile("myfile", ".scala").nn) { file =>
+      wconfSrcFilterTest(
+        argsStr = "-Wconf:src=myfile.*?\\.scala:s",
+        source = util.SourceFile(new PlainFile(Path(file)), "UTF-8"),
+        expectedAction = reporting.Action.Silent
+      )
+    }(Files.deleteIfExists(_))
+
+  @Test def `WConf src filter doesn't silence warnings from a non-matching path for real file`: Unit =
+    Using.resource(Files.createTempFile("myfile", ".scala").nn) { file =>
+      wconfSrcFilterTest(
+        argsStr = "-Wconf:src=another.*?\\.scala:s",
+        source = util.SourceFile(new PlainFile(Path(file)), "UTF-8"),
+        expectedAction = reporting.Action.Warning
+      )
+    }(Files.deleteIfExists(_))
+
+  @Test def `WConf src filter works when cache is not empty`: Unit =
+    (0 to 1).foreach { _ =>
+      wconfSrcFilterTest(
+        argsStr = "-Wconf:src=path/.*:s",
+        source = util.SourceFile.virtual(new URI("file:///some/path/file.scala"), ""),
+        expectedAction = reporting.Action.Silent
+      )
+    }
 
 end ScalaSettingsTests