1 files changed, 65 insertions, 7 deletions
diff --git a/doc-tool/src/dotty/tools/dottydoc/staticsite/Template.scala b/doc-tool/src/dotty/tools/dottydoc/staticsite/Template.scala
index 00d51f083..9720084f3 100644
--- a/doc-tool/src/dotty/tools/dottydoc/staticsite/Template.scala
+++ b/doc-tool/src/dotty/tools/dottydoc/staticsite/Template.scala
@@ -3,7 +3,11 @@ package dottydoc
 package staticsite
 
 import scala.util.control.NonFatal
+
 import dotc.util.SourceFile
+import dotc.core.Contexts.Context
+import dotc.util.Positions.{ Position, NoPosition }
+import util.syntax._
 
 trait Template {
   def path: String
@@ -18,8 +22,9 @@ case class Layout(path: String, content: SourceFile) extends Template
 
 case class Include(path: String, content: SourceFile) extends Template
 
-case class LiquidTemplate(path: String, content: String) extends ResourceFinder {
+case class LiquidTemplate(path: String, content: SourceFile) extends Template with ResourceFinder {
   import scala.collection.JavaConverters._
+  import dotc.printing.Highlighting._
   import liqp.Template
   import liqp.filters.Filter
   import liqp.parser.Flavor.JEKYLL
@@ -38,16 +43,69 @@ case class LiquidTemplate(path: String, content: String) extends ResourceFinder
       map
     }
 
-  def render(params: Map[String, AnyRef], includes: Map[String, Include]): String =
-    try {
-      Template.parse(content, JEKYLL)
+  private def protectedRender(op: => String)(implicit ctx: Context) = try {
+    Some(op)
+  } catch {
+    case NonFatal(ex) => {
+      // TODO: when we reimplement the liquid parser, this can go away. For now
+      // this is an OK approximation of what went wrong.
+      if ((ex.getCause eq null) || ex.getMessage.contains("exceeded the max amount of time")) {
+        ctx.docbase.error(
+          "unknown error occurred in " +
+          Blue(path).toString +
+          ", most likely incorrect usage of tag"
+        )
+        None
+      }
+      else ex.getCause match {
+        case mm: org.antlr.runtime.MismatchedTokenException => {
+          val unexpected = LiquidTemplate.token(mm.getUnexpectedType)
+          val expected = LiquidTemplate.token(mm.expecting)
+
+          ctx.error(
+            if (unexpected == "EOF")
+              s"unexpected end of file, expected: '$expected'"
+            else
+              s"unexpected token '$unexpected', expected: '$expected'",
+            content atPos Position(mm.index)
+          )
+
+          None
+        }
+        case ex => {
+          if (true || ctx.settings.debug.value)
+            throw ex
+
+          None
+        }
+      }
+    }
+  }
+
+  def render(params: Map[String, AnyRef], includes: Map[String, Include])(implicit ctx: Context): Option[String] =
+    protectedRender {
+      Template.parse(show, JEKYLL)
         .`with`(ResourceInclude(params, includes))
         .`with`(RenderReference(params))
         .`with`(RenderTitle(params))
         .`with`(Docstring(params))
         .render(toJavaMap(params))
-    } catch {
-      case NonFatal(ex) =>
-        throw TemplateRenderingError(path, ex)
     }
 }
+
+object LiquidTemplate {
+  import liqp.parser.LiquidParser
+
+  private val _tokens: Map[String, String] = Map(
+    "TagStart" -> "{%",
+    "TagEnd"   -> "%}"
+  )
+
+  def token(i: Int): String =
+    if (i == -1) "EOF"
+    else if (i >= LiquidParser.tokenNames.length)
+      "non-existing token"
+    else _tokens
+      .get(LiquidParser.tokenNames(i))
+      .getOrElse(s"token  $i")
+}