chore: Show errors from crashes

Currently AssertionError, FatalError and IllegalArgument exceptions are sometimes enriched with additional information, which we can try to parse.

Author: tgodzik

backend/src/main/scala/bloop/Compiler.scala

@@ -10,6 +10,7 @@ import java.util.concurrent.Executor
 
 import scala.collection.mutable
 import scala.concurrent.Promise
+import scala.tools.nsc.FatalError
 import scala.util.Try
 
 import bloop.Compiler.Result.Failed
@@ -21,6 +22,7 @@ import bloop.io.{Paths => BloopPaths}
 import bloop.logging.DebugFilter
 import bloop.logging.Logger
 import bloop.logging.ObservedLogger
+import bloop.reporter.ObservedReporter
 import bloop.reporter.ProblemPerPhase
 import bloop.reporter.Reporter
 import bloop.reporter.ZincReporter
@@ -31,6 +33,7 @@ import bloop.util.AnalysisUtils
 import bloop.util.BestEffortUtils
 import bloop.util.BestEffortUtils.BestEffortProducts
 import bloop.util.CacheHashCode
+import bloop.util.HashedSource
 import bloop.util.JavaRuntime
 import bloop.util.UUIDUtil
 
@@ -47,7 +50,6 @@ import sbt.util.InterfaceUtil
 import xsbti.T2
 import xsbti.VirtualFileRef
 import xsbti.compile._
-import bloop.util.HashedSource
 
 case class CompileInputs(
     scalaInstance: ScalaInstance,
@@ -783,7 +785,33 @@ object Compiler {
               val backgroundTasks =
                 toBackgroundTasks(backgroundTasksForFailedCompilation.toList)
               val failedProblems = findFailedProblems(reporter, None)
-              Result.Failed(failedProblems, Some(t), elapsed, backgroundTasks, None)
+              val errorFromThrowable = t match {
+                case _: AssertionError | _: FatalError | _: IllegalArgumentException =>
+                  bloop.reporter.Problem.fromError(t) match {
+                    case Some(problem) =>
+                      reporter match {
+                        case observedReporter: ObservedReporter =>
+                          observedReporter.log(problem)
+                        case _ =>
+                      }
+                      List(
+                        ProblemPerPhase(
+                          problem,
+                          phase = None
+                        )
+                      )
+
+                    case None => Nil
+                  }
+                case _ => Nil
+              }
+              Result.Failed(
+                failedProblems ++ errorFromThrowable,
+                Some(t),
+                elapsed,
+                backgroundTasks,
+                None
+              )
           }
       }
   }

frontend/src/test/scala/bloop/bsp/BspCompileSpec.scala

@@ -8,6 +8,7 @@ import java.util.concurrent.TimeUnit
 import scala.collection.JavaConverters._
 import scala.concurrent.duration.FiniteDuration
 
+import bloop.Compiler.Result.Failed
 import bloop.cli.BspProtocol
 import bloop.cli.ExitStatus
 import bloop.internal.build.BuildInfo
@@ -1422,5 +1423,69 @@ class BspCompileSpec(
       runTest(2000)
     }
   }
+  test("crash-compiler-diagnostics") {
+    TestUtil.withinWorkspace { workspace =>
+      // Macro project - must be compiled first
+      val macroProject = TestProject(
+        workspace,
+        "macros",
+        List(
+          """/main/scala/FooMacro.scala
+            |package macros
+            |
+            |import scala.language.experimental.macros
+            |import scala.reflect.macros.blackbox
+            |
+            |object FooMacro {
+            |  def crashNow: Int = macro crashNowImpl
+            |
+            |  def crashNowImpl(c: blackbox.Context): c.Expr[Int] = {
+            |    import c.universe._
+            |    val badSymbol = c.internal.newTermSymbol(NoSymbol, TermName("badSymbol"))
+            |    val badTree = Ident(badSymbol)
+            |    c.Expr[Int](badTree)
+            |  }
+            |}
+            |
+            |
+          """.stripMargin
+        )
+      )
+      // Fast file that will be modified to break compilation if stale bytecode is used
+      val downstreamFile =
+        """/main/scala/a/FastCompilation.scala
+          |package a
+          |import macros.FooMacro
+          |
+          |case class User(name: Int, age: Int)
+          |
+          |object Bar{
+          |  def baz2 = FooMacro.crashNow
+          |
+          |}
+          |
+        """.stripMargin
+
+      val logger = new RecordingLogger(ansiCodesSupported = false)
+      val testProject = TestProject(
+        workspace,
+        "a",
+        List(downstreamFile),
+        List(macroProject),
+        scalaVersion = Some("2.13.16")
+      )
+      val projects = List(macroProject, testProject)
+      loadBspState(workspace, projects, logger) { state =>
+        val macroCompiled = state.compile(macroProject)
+        assert(macroCompiled.status == ExitStatus.Ok)
+        val downstreamCompiled = state.compile(testProject)
+        assert(downstreamCompiled.status == ExitStatus.CompilationError)
+        val lastDiagnostics = downstreamCompiled.lastDiagnostics(testProject)
+        assertContains(lastDiagnostics, "badSymbol")
+        assertContains(lastDiagnostics, "tree position: line 7 of ")
+        assertContains(lastDiagnostics, "a/src/main/scala/a/FastCompilation.scala")
+      }
+    }
+  }
 
 }

shared/src/main/scala/bloop/reporter/Problem.scala

@@ -3,6 +3,9 @@ package bloop.reporter
 import java.util.Optional
 
 import xsbti.Severity
+import java.util.ArrayList
+import java.io.File
+import java.nio.file.Paths
 
 /** Describes a problem (error, warning, message, etc.) given to the reporter. */
 final case class Problem private (
@@ -36,6 +39,45 @@ object Problem {
     )
   }
 
+  def fromError(error: Throwable): Option[Problem] = {
+    val assertionErrorRegex = """tree position: line (\d+) of (.+\.scala)""".r
+    assertionErrorRegex.findFirstMatchIn(error.getMessage()) match {
+      case Some(m) =>
+        val line = m.group(1).toInt
+        val file = Paths.get(m.group(2)).toFile()
+        Some(
+          Problem(
+            -1,
+            xsbti.Severity.Error,
+            error.getMessage(),
+            BloopPosition(file, Optional.of(line)),
+            "assertion error",
+            Optional.empty(),
+            new ArrayList[xsbti.DiagnosticRelatedInformation](),
+            new ArrayList[xsbti.Action]()
+          )
+        )
+      case None => // No match
+        None
+    }
+  }
+
+  case class BloopPosition(file: File, line: Optional[Integer]) extends xsbti.Position {
+
+    override def lineContent(): String = ""
+
+    override def offset(): Optional[Integer] = Optional.empty()
+
+    override def pointer(): Optional[Integer] = Optional.empty()
+
+    override def pointerSpace(): Optional[String] = Optional.empty()
+
+    override def sourcePath(): Optional[String] = Optional.empty()
+
+    override def sourceFile(): Optional[File] = Optional.of(file)
+
+  }
+
   case class DiagnosticsCount(errors: Long, warnings: Long) {
     override def toString: String = s"$errors errors, $warnings warnings"
   }