use compiler impl of protobuf for presentation compiler

zinc 1.4 removes the dependency on protobuf-java, so fails
to compile mtags-shared due to the now missing transitive
dependency.

The compiler implements protobuf streams for semanticdb, so reuse
it in the source generator for mtags-shared.

Author: bishabosha

project/Build.scala

@@ -527,6 +527,33 @@ object Build {
     recur(lines, false)
   }
 
+  /** replace imports of `com.google.protobuf.*` with compiler implemented version */
+  def replaceProtobuf(lines: List[String]): List[String] = {
+    def recur(ls: List[String]): List[String] = ls match {
+      case l :: rest =>
+        val lt = l.trim()
+        if (lt.isEmpty || lt.startsWith("package ") || lt.startsWith("import ")) {
+          val newLine =
+            if (lt.startsWith("import com.google.protobuf.")) {
+              if (lt == "import com.google.protobuf.CodedInputStream") {
+                "import dotty.tools.dotc.semanticdb.internal.SemanticdbInputStream as CodedInputStream"
+              } else if (lt == "import com.google.protobuf.CodedOutputStream") {
+                "import dotty.tools.dotc.semanticdb.internal.SemanticdbOutputStream as CodedOutputStream"
+              } else {
+                l
+              }
+            } else {
+              l
+            }
+          newLine :: recur(rest)
+        } else {
+          ls // don't check rest of file
+        }
+      case _ => ls
+    }
+    recur(lines)
+  }
+
   // Settings shared between scala3-compiler and scala3-compiler-bootstrapped
   lazy val commonDottyCompilerSettings = Seq(
        // Note: bench/profiles/projects.yml should be updated accordingly.
@@ -556,7 +583,7 @@ object Build {
       // get libraries onboard
       libraryDependencies ++= Seq(
         "org.scala-lang.modules" % "scala-asm" % "9.5.0-scala-1", // used by the backend
-        Dependencies.newCompilerInterface, // we stick to the old version to avoid deprecation warnings
+        Dependencies.compilerInterface,
         "org.jline" % "jline-reader" % "3.19.0",   // used by the REPL
         "org.jline" % "jline-terminal" % "3.19.0",
         "org.jline" % "jline-terminal-jna" % "3.19.0", // needed for Windows
@@ -1140,8 +1167,7 @@ object Build {
       // when sbt reads the settings.
       Test / test := (LocalProject("scala3-sbt-bridge-tests") / Test / test).value,
 
-      // The `newCompilerInterface` is backward compatible with the `oldCompilerInterface`
-      libraryDependencies += Dependencies.newCompilerInterface % Provided
+      libraryDependencies += Dependencies.compilerInterface % Provided
     )
 
   // We use a separate project for the bridge tests since they can only be run
@@ -1225,7 +1251,8 @@ object Build {
           val mtagsSharedSources = (targetDir ** "*.scala").get.toSet
           mtagsSharedSources.foreach(f => {
             val lines = IO.readLines(f)
-            IO.writeLines(f, insertUnsafeNullsImport(lines))
+            val substitutions = (replaceProtobuf(_)) andThen (insertUnsafeNullsImport(_))
+            IO.writeLines(f, substitutions(lines))
           })
           mtagsSharedSources
         } (Set(mtagsSharedSourceJar)).toSeq

project/Dependencies.scala

@@ -28,6 +28,5 @@ object Dependencies {
     "com.vladsch.flexmark" % "flexmark-ext-yaml-front-matter" % flexmarkVersion,
   )
 
-  val newCompilerInterface = "org.scala-sbt" % "compiler-interface" % "1.9.0"
-  // val oldCompilerInterface = "org.scala-sbt" % "compiler-interface" % "1.3.5"
+  val compilerInterface = "org.scala-sbt" % "compiler-interface" % "1.9.0"
 }