allow filtering messages by error id

Author: lrytz

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

@@ -149,10 +149,13 @@ private sealed trait WarningSettings:
          |  - Message content: msg=regex
          |    The regex need only match some part of the message, not all of it.
          |
+         |  - Message id: id=E129
+         |    The message id is printed with the warning.
+         |
          |<action>
          |  - error / e
          |  - warning / w
-         |  - info / i    (infos are not counted as warnings and don't affect `-Werror`)
+         |  - info / i    (infos are not counted as warnings and not affected by `-Werror`)
          |  - silent / s
          |
          |The default configuration is empty.

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

@@ -6,6 +6,7 @@ import dotty.tools.dotc.core.Contexts._
 import dotty.tools.dotc.util.SourcePosition
 
 import java.util.regex.PatternSyntaxException
+import scala.annotation.internal.sharable
 import scala.collection.mutable.ListBuffer
 import scala.util.matching.Regex
 
@@ -17,10 +18,12 @@ enum MessageFilter:
     case MessagePattern(pattern) =>
       val noHighlight = message.msg.rawMessage.replaceAll("\\e\\[[\\d;]*[^\\d;]","")
       pattern.findFirstIn(noHighlight).nonEmpty
+    case MessageID(errorId) => message.msg.errorId == errorId
     case None => false
   }
   case Any, Deprecated, Feature, None
   case MessagePattern(pattern: Regex)
+  case MessageID(errorId: ErrorMessageID)
 
 enum Action:
   case Error, Warning, Info, Silent
@@ -48,18 +51,28 @@ object WConf:
     try Right(s.r)
     catch { case e: PatternSyntaxException => Left(s"invalid pattern `$s`: ${e.getMessage}") }
 
-  def parseFilter(s: String): Either[String, MessageFilter] =
-    val splitter = raw"([^=]+)=(.+)".r
-    s match
-      case "any" => Right(Any)
-      case splitter(filter, conf) => filter match
-        case "msg" => regex(conf).map(MessagePattern.apply)
-        case "cat" => conf match
-          case "deprecation" => Right(Deprecated)
-          case "feature"     => Right(Feature)
-          case _             => Left(s"unknown category: $conf")
-        case _ => Left(s"unknown filter: $filter")
-      case _ => Left(s"unknown filter: $s")
+  @sharable val Splitter = raw"([^=]+)=(.+)".r
+  @sharable val ErrorId = raw"E?(\d+)".r
+
+  def parseFilter(s: String): Either[String, MessageFilter] = s match
+    case "any" => Right(Any)
+    case Splitter(filter, conf) => filter match
+      case "msg" => regex(conf).map(MessagePattern.apply)
+      case "id" => conf match
+        case ErrorId(num) =>
+          val n = num.toInt + 2
+          if n < ErrorMessageID.values.length then
+            Right(MessageID(ErrorMessageID.fromOrdinal(n)))
+          else
+            Left(s"unknonw error message id: E$n")
+        case _ =>
+          Left(s"invalid error message id: $conf")
+      case "cat" => conf match
+        case "deprecation" => Right(Deprecated)
+        case "feature"     => Right(Feature)
+        case _             => Left(s"unknown category: $conf")
+      case _ => Left(s"unknown filter: $filter")
+    case _ => Left(s"unknown filter: $s")
 
   def parsed(using Context): WConf =
     val setting = ctx.settings.Wconf.value

tests/neg-custom-args/nowarn/nowarn-parser-typer.check

@@ -4,6 +4,13 @@
   |          A try without catch or finally is equivalent to putting
   |          its body in a block; no exceptions are handled.
 
+longer explanation available when compiling with `-explain`
+-- [E000] Syntax Error: tests/neg-custom-args/nowarn/nowarn-parser-typer.scala:22:26 -----------------------------------
+22 |@nowarn("id=1") def t5d = try 1 // error, wrong id
+   |                          ^^^^^
+   |                          A try without catch or finally is equivalent to putting
+   |                          its body in a block; no exceptions are handled.
+
 longer explanation available when compiling with `-explain`
 -- [E129] Potential Issue Error: tests/neg-custom-args/nowarn/nowarn-parser-typer.scala:16:11 --------------------------
 16 |def t3 = { 1; 2 } // error, the invalid nowarn doesn't silence this warning

tests/neg-custom-args/nowarn/nowarn-parser-typer.scala

@@ -14,3 +14,9 @@ def t2 = f // not reported because refchecks doesn't run
 
 @nowarn("wat?") // error, invalid filter
 def t3 = { 1; 2 } // error, the invalid nowarn doesn't silence this warning
+
+@nowarn("id=E129") def t4 = { 1; 2 }
+@nowarn("id=E000") def t5a = try 1
+@nowarn("id=E0") def t5b = try 1
+@nowarn("id=0") def t5c = try 1
+@nowarn("id=1") def t5d = try 1 // error, wrong id