Run AppendDiagnostics phase after crossVersionChecks

So that we can add deprecation warnings to SemanticDB

Author: tanishiking

compiler/src/dotty/tools/dotc/Compiler.scala

@@ -38,7 +38,7 @@ class Compiler {
     List(new CheckUnused.PostTyper) ::  // Check for unused elements
     List(new YCheckPositions) ::    // YCheck positions
     List(new sbt.ExtractDependencies) :: // Sends information on classes' dependencies to sbt via callbacks
-    List(new semanticdb.ExtractSemanticDB.PostTyper) :: // Extract info and attach to the tree of the unit file
+    List(new semanticdb.ExtractSemanticDB.ExtractSemanticInfo) :: // Extract info and attach to the tree of the unit file
     List(new PostTyper) ::          // Additional checks and cleanups after type checking
     List(new sjs.PrepJSInterop) ::  // Additional checks and transformations for Scala.js (Scala.js only)
     List(new sbt.ExtractAPI) ::     // Sends a representation of the API of classes to sbt via callbacks
@@ -51,7 +51,6 @@ class Compiler {
     List(new Inlining) ::           // Inline and execute macros
     List(new PostInlining) ::       // Add mirror support for inlined code
     List(new CheckUnused.PostInlining) ::  // Check for unused elements
-    List(new semanticdb.ExtractSemanticDB.PostInlining) :: // Attach warnings to extracted SemanticDB and write to .semanticdb file
     List(new Staging) ::            // Check staging levels and heal staged types
     List(new Splicing) ::           // Replace level 1 splices with holes
     List(new PickleQuotes) ::       // Turn quoted trees into explicit run-time data structures
@@ -72,6 +71,7 @@ class Compiler {
          new ExpandSAMs,             // Expand single abstract method closures to anonymous classes
          new ElimRepeated,           // Rewrite vararg parameters and arguments
          new RefChecks) ::           // Various checks mostly related to abstract members and overriding
+    List(new semanticdb.ExtractSemanticDB.AppendDiagnostics) :: // Attach warnings to extracted SemanticDB and write to .semanticdb file
     List(new init.Checker) ::        // Check initialization of objects
     List(new ProtectedAccessors,     // Add accessors for protected members
          new ExtensionMethods,       // Expand methods of value classes with extension methods

compiler/src/dotty/tools/dotc/semanticdb/ExtractSemanticDB.scala

@@ -62,24 +62,24 @@ class ExtractSemanticDB private (phaseMode: ExtractSemanticDB.PhaseMode, suffix:
   override def isCheckable: Boolean = false
 
   override def runOn(units: List[CompilationUnit])(using ctx: Context): List[CompilationUnit] = {
-    val appendWarnings = phaseMode == ExtractSemanticDB.PhaseMode.PostInlining
+    val appendDiagnostics = phaseMode == ExtractSemanticDB.PhaseMode.AppendDiagnostics
     val warnings =
-      if (appendWarnings)
+      if (appendDiagnostics)
         ctx.reporter.allWarnings.groupBy(w => w.pos.source)
       else Map.empty
 
-    units.asJava.parallelStream().map { unit =>
+    units.asJava.parallelStream().forEach { unit =>
       val unitCtx = ctx.fresh.setCompilationUnit(unit).withRootImports
-      if (appendWarnings)
+      if (appendDiagnostics)
         warnings.get(unit.source).foreach { ws =>
           ExtractSemanticDB.appendDiagnostics(unit.source, ws.map(_.toSemanticDiagnostic))
         }
       else
         val extractor = ExtractSemanticDB.Extractor()
         extractor.extract(unit.tpdTree)
         ExtractSemanticDB.write(unit.source, extractor.occurrences.toList, extractor.symbolInfos.toList, extractor.synthetics.toList)
-      unit
-    }.toList().asScala.toList
+    }
+    units
   }
 
   def run(using Context): Unit = unsupported("run")
@@ -94,12 +94,12 @@ object ExtractSemanticDB:
   val description: String = "extract info into .semanticdb files"
 
   enum PhaseMode:
-    case PostTyper
-    case PostInlining
+    case ExtractSemanticInfo
+    case AppendDiagnostics
 
-  class PostTyper extends ExtractSemanticDB(PhaseMode.PostTyper, "PostTyper")
+  class ExtractSemanticInfo extends ExtractSemanticDB(PhaseMode.ExtractSemanticInfo, "ExtractSemanticInfo")
 
-  class PostInlining extends ExtractSemanticDB(PhaseMode.PostInlining, "PostInlining")
+  class AppendDiagnostics extends ExtractSemanticDB(PhaseMode.AppendDiagnostics, "AppendDiagnostics")
 
   private def semanticdbTarget(using Context): Option[Path] =
     Option(ctx.settings.semanticdbTarget.value)

tests/semanticdb/expect/Deprecated.expect.scala

@@ -0,0 +1,4 @@
+object Deprecated/*<-_empty_::Deprecated.*/ {
+  @deprecated/*->scala::deprecated#*/ def deprecatedMethod/*<-_empty_::Deprecated.deprecatedMethod().*/ = ???/*->scala::Predef.`???`().*/
+  def main/*<-_empty_::Deprecated.main().*/ = deprecatedMethod/*->_empty_::Deprecated.deprecatedMethod().*/
+}

tests/semanticdb/expect/Deprecated.scala

@@ -0,0 +1,4 @@
+object Deprecated {
+  @deprecated def deprecatedMethod = ???
+  def main = deprecatedMethod
+}

tests/semanticdb/metac.expect

@@ -731,6 +731,34 @@ Synthetics:
 [51:16..51:27):List(1).map => *[Int]
 [51:16..51:20):List => *.apply[Int]
 
+expect/Deprecated.scala
+-----------------------
+
+Summary:
+Schema => SemanticDB v4
+Uri => Deprecated.scala
+Text => empty
+Language => Scala
+Symbols => 3 entries
+Occurrences => 6 entries
+Diagnostics => 1 entries
+
+Symbols:
+_empty_/Deprecated. => final object Deprecated extends Object { self: Deprecated.type => +3 decls }
+_empty_/Deprecated.deprecatedMethod(). => @deprecated method deprecatedMethod => Nothing
+_empty_/Deprecated.main(). => method main => Nothing
+
+Occurrences:
+[0:7..0:17): Deprecated <- _empty_/Deprecated.
+[1:3..1:13): deprecated -> scala/deprecated#
+[1:18..1:34): deprecatedMethod <- _empty_/Deprecated.deprecatedMethod().
+[1:37..1:40): ??? -> scala/Predef.`???`().
+[2:6..2:10): main <- _empty_/Deprecated.main().
+[2:13..2:29): deprecatedMethod -> _empty_/Deprecated.deprecatedMethod().
+
+Diagnostics:
+[2:13..2:29): [warning] method deprecatedMethod in object Deprecated is deprecated
+
 expect/Empty.scala
 ------------------