Check for tasty error in Template trees.

Author: lidaisy

Diff for: compiler/src/dotty/tools/dotc/transform/init/Semantic.scala

@@ -448,20 +448,18 @@ object Semantic:
   object TreeCache:
     class CacheData:
       private val emptyTrees = mutable.Set[ValOrDefDef]()
-      private val emptyTemplates = mutable.Set[Template]()
+      private val templatesToSkip = mutable.Set[Template]()
 
-      def checkTemplateBodyValidity(tpl: Template, className: String)(using Context): Unit = {
-        if (emptyTemplates.contains(tpl))
-          throw new Exception("Error in body of " + className)
+      def checkTemplateBodyValidity(tpl: Template, className: String)(using Context): Unit =
+        if (templatesToSkip.contains(tpl))
+          throw new TastyTreeException(className)
 
         val errorCount = ctx.reporter.errorCount
         tpl.forceFields()
 
         if (ctx.reporter.errorCount > errorCount)
-          report.warning("Skipping the analysis of " + className + " due to an error reading the body of " + className + "'s TASTy.")
-          emptyTemplates.add(tpl)
-          throw new Exception("Error in body of " + className)
-      }
+          templatesToSkip.add(tpl)
+          throw new TastyTreeException(className)
 
       extension (tree: ValOrDefDef)
         def getRhs(using Context): Tree =
@@ -1193,7 +1191,7 @@ object Semantic:
       try
         checkClass(classSym)
       catch
-        case e: Exception =>
+        case TastyTreeException(className) => report.warning("Skipping the analysis of " + classSym.show + " due to an error reading the body of " + className + "'s TASTy.")
 
 // ----- Semantic definition --------------------------------
   type ArgInfo = TraceValue[Value]

Diff for: compiler/src/dotty/tools/dotc/transform/init/Util.scala

@@ -15,6 +15,9 @@ import config.Printers.init as printer
 import Trace.*
 
 object Util:
+  /** Exception used for errors encountered when reading TASTy. */
+  case class TastyTreeException(msg: String) extends RuntimeException(msg)
+  
   /** Utility definition used for better error-reporting of argument errors */
   case class TraceValue[T](value: T, trace: Trace)
 

Diff for: compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -297,12 +297,12 @@ class CompilationTests {
     }
 
     /* This tests for errors in the program's TASTy trees.
-     * The test consists of four files: C, v1/A, v1/B, and v0/A. v1/A, v1/B, and v0/A all depend on C. v1/A and v1/B are
+     * The test consists of five files: Main, C, v1/A, v1/B, and v0/A. The files v1/A, v1/B, and v0/A all depend on C. v1/A and v1/B are
      * compatible, but v1/B and v0/A are not. If v1/B and v0/A are compiled together, there should be
-     * an error when reading the files' TASTy trees. */
+     * an error when reading the files' TASTy trees. This fact is demonstrated by the compilation of Main. */
     locally {
       val tastyErrorGroup = TestGroup("checkInit/tasty-error/typedef")
-      val tastyErrorOptions = options.without("-Xfatal-warnings")
+      val tastyErrorOptions = options.without("-Xfatal-warnings").without("-Ycheck:all")
 
       val classC = defaultOutputDir + tastyErrorGroup + "/C/typedef/C"
       val classA0 = defaultOutputDir + tastyErrorGroup + "/A/v0/A"
@@ -317,7 +317,6 @@ class CompilationTests {
       ).map(_.keepOutput.checkCompile())
 
       compileFile("tests/init/tasty-error/typedef/Main.scala", tastyErrorOptions.withClasspath(classC).withClasspath(classA0).withClasspath(classB1))(tastyErrorGroup).checkExpectedErrors()
-      compileFile("tests/init/tasty-error/typedef/DependOnB.scala", tastyErrorOptions.withClasspath(classC).withClasspath(classA0).withClasspath(classB1))(tastyErrorGroup).checkCompile()
 
       tests.foreach(_.delete())
     }

Diff for: tests/init/tasty-error/typedef/DependOnB.scala

@@ -1 +1,2 @@
-class Main extends B{} // anypos-error
+class Main extends B{} // anypos-error
+class ExtendsB extends B{}