Merge pull request #6820 from dotty-staging/quote-error-on-quote-context

Move macro error reporting to QuoteContext

Author: nicolasstucki

community-build/community-projects/scalatest

@@ -45,16 +45,6 @@ object Splicer {
         interpretedExpr.fold(tree)(x => PickledQuotes.quotedExprToTree(x))
       }
       catch {
-        case ex: scala.quoted.QuoteError =>
-          val pos1 = ex.from match {
-            case None => pos
-            case Some(expr) =>
-              val reflect: scala.tasty.Reflection = ReflectionImpl(ctx)
-              import reflect._
-              expr.unseal.underlyingArgument.pos.asInstanceOf[SourcePosition]
-          }
-          ctx.error(ex.getMessage, pos1)
-          EmptyTree
         case NonFatal(ex) =>
           val msg =
             s"""Failed to evaluate macro.
@@ -205,19 +195,13 @@ object Splicer {
           sw.write("\n")
           throw new StopInterpretation(sw.toString, pos)
         case ex: InvocationTargetException =>
-          ex.getCause match {
-            case cause: scala.quoted.QuoteError =>
-              throw cause
-            case _ =>
-              val sw = new StringWriter()
-              sw.write("An exception occurred while executing macro expansion\n")
-              sw.write(ex.getTargetException.getMessage)
-              sw.write("\n")
-              ex.getTargetException.printStackTrace(new PrintWriter(sw))
-              sw.write("\n")
-              throw new StopInterpretation(sw.toString, pos)
-          }
-
+          val sw = new StringWriter()
+          sw.write("An exception occurred while executing macro expansion\n")
+          sw.write(ex.getTargetException.getMessage)
+          sw.write("\n")
+          ex.getTargetException.printStackTrace(new PrintWriter(sw))
+          sw.write("\n")
+          throw new StopInterpretation(sw.toString, pos)
       }
     }
 

compiler/src/dotty/tools/dotc/transform/Splicer.scala

@@ -53,28 +53,25 @@ object StringContextMacro {
     def restoreReported() : Unit
   }
 
-  /** Retrieves a String from an Expr containing it
-   *
-   *  @param expression the Expr containing the String
-   *  @return the String contained in the given Expr
-   *  quotes an error if the given Expr does not contain a String
-   */
-  private def literalToString(expression : Expr[String]) given (ctx: QuoteContext) : String = expression match {
-    case Const(string : String) => string
-    case _ => QuoteError("Expected statically known literal", expression)
-  }
-
   /** Retrieves the parts from a StringContext, given inside an Expr, and returns them as a list of Expr of String
    *
    *  @param strCtxExpr the Expr containing the StringContext
    *  @return a list of Expr containing Strings, each corresponding to one parts of the given StringContext
    *  quotes an error if the given Expr does not correspond to a StringContext
    */
-  def getPartsExprs(strCtxExpr : Expr[scala.StringContext]) given QuoteContext: List[Expr[String]] = {
+  def getPartsExprs(strCtxExpr : Expr[scala.StringContext]) given (qctx: QuoteContext): Option[(List[Expr[String]], List[String])] = {
+    def notStatic = {
+      qctx.error("Expected statically known String Context", strCtxExpr)
+      None
+    }
+    def splitParts(seq: Expr[Seq[String]]) = (seq, seq) match {
+      case (ExprSeq(p1), ConstSeq(p2)) => Some((p1.toList, p2.toList))
+      case _ => notStatic
+    }
     strCtxExpr match {
-      case '{ StringContext(${ExprSeq(parts)}: _*) } => parts.toList
-      case '{ new StringContext(${ExprSeq(parts)}: _*) } => parts.toList
-      case _ => QuoteError("Expected statically known String Context", strCtxExpr)
+      case '{ StringContext($parts: _*) } => splitParts(parts)
+      case '{ new StringContext($parts: _*) } => splitParts(parts)
+      case _ => notStatic
     }
   }
 
@@ -84,11 +81,14 @@ object StringContextMacro {
    *  @return a list of Expr containing arguments
    *  quotes an error if the given Expr does not contain a list of arguments
    */
-  def getArgsExprs(argsExpr: Expr[Seq[Any]]) given (qctx: QuoteContext): List[Expr[Any]] = {
+  def getArgsExprs(argsExpr: Expr[Seq[Any]]) given (qctx: QuoteContext): Option[List[Expr[Any]]] = {
     import qctx.tasty._
     argsExpr.unseal.underlyingArgument match {
-      case Typed(Repeated(args, _), _) => args.map(_.seal)
-      case tree => QuoteError("Expected statically known argument list", argsExpr)
+      case Typed(Repeated(args, _), _) =>
+        Some(args.map(_.seal))
+      case tree =>
+        qctx.error("Expected statically known argument list", argsExpr)
+        None
     }
   }
 
@@ -102,8 +102,14 @@ object StringContextMacro {
     import qctx.tasty._
     val sourceFile = strCtxExpr.unseal.pos.sourceFile
 
-    val partsExpr = getPartsExprs(strCtxExpr)
-    val args = getArgsExprs(argsExpr)
+    val (partsExpr, parts) = getPartsExprs(strCtxExpr) match {
+      case Some(x) => x
+      case None => return '{""}
+    }
+    val args = getArgsExprs(argsExpr) match {
+      case Some(args) => args
+      case None => return '{""}
+    }
 
     val reporter = new Reporter{
       private[this] var reported = false
@@ -148,7 +154,7 @@ object StringContextMacro {
       }
     }
 
-    interpolate(partsExpr, args, argsExpr, reporter)
+    interpolate(parts, args, argsExpr, reporter)
   }
 
   /** Helper function for the interpolate function above
@@ -158,7 +164,7 @@ object StringContextMacro {
    *  @param reporter the reporter to return any error/warning when a problem is encountered
    *  @return the Expr containing the formatted and interpolated String or an error/warning report if the parameters are not correct
    */
-  def interpolate(partsExpr : List[Expr[String]], args : List[Expr[Any]], argsExpr: Expr[Seq[Any]], reporter : Reporter) given (qctx: QuoteContext) : Expr[String] = {
+  def interpolate(parts0 : List[String], args : List[Expr[Any]], argsExpr: Expr[Seq[Any]], reporter : Reporter) given (qctx: QuoteContext) : Expr[String] = {
     import qctx.tasty._
 
     /** Checks if the number of arguments are the same as the number of formatting strings
@@ -721,10 +727,10 @@ object StringContextMacro {
     val argument = args.size
 
     // check validity of formatting
-    checkSizes(partsExpr.size - 1, argument)
+    checkSizes(parts0.size - 1, argument)
 
     // add default format
-    val parts = addDefaultFormat(partsExpr.map(literalToString))
+    val parts = addDefaultFormat(parts0)
 
     if (!parts.isEmpty && !reporter.hasReported()) {
       if (parts.size == 1 && args.size == 0 && parts.head.size != 0){

library/src-bootstrapped/dotty/internal/StringContextMacro.scala

@@ -3,8 +3,10 @@ package scala.quoted
 /** Throwing this error in the implementation of a macro
  *  will result in a compilation error with the given message.
  */
+@deprecated("", "0.17")
 class QuoteError(message: String, val from: Option[Expr[_]]) extends Throwable(message)
 
+@deprecated("", "0.17")
 object QuoteError {
   /** Throws a QuoteError with the given message */
   def apply(message: => String): Nothing = throw new QuoteError(message, None)

library/src/scala/quoted/QuoteError.scala renamed to library/src-non-bootstrapped/scala/quoted/QuoteError.scala

@@ -22,6 +22,30 @@ class QuoteContext(val tasty: scala.tasty.Reflection) {
     tpe.unseal.show(syntaxHighlight)
   }
 
+  /** Report an error */
+  def error(msg: => String): Unit = {
+    import tasty._
+    tasty.error(msg, rootPosition) given rootContext
+  }
+
+  /** Report an error at the on the position of `expr` */
+  def error(msg: => String, expr: Expr[_]): Unit = {
+    import tasty._
+    tasty.error(msg, expr.unseal.pos) given rootContext
+  }
+
+  /** Report a warning */
+  def warning(msg: => String): Unit = {
+    import tasty._
+    tasty.warning(msg, rootPosition) given rootContext
+  }
+
+  /** Report a warning at the on the position of `expr` */
+  def warning(msg: => String, expr: Expr[_]): Unit = {
+    import tasty._
+    tasty.warning(msg, expr.unseal.pos) given rootContext
+  }
+
 }
 
 object QuoteContext {

library/src/scala/quoted/QuoteContext.scala

@@ -5,8 +5,8 @@ object Macro_1 {
   def fooImpl(b: Boolean) given QuoteContext: Expr[Unit] =
     '{println(${msg(b)})}
 
-  def msg(b: Boolean) given QuoteContext: Expr[String] =
+  def msg(b: Boolean) given (qctx: QuoteContext): Expr[String] =
     if (b) '{"foo(true)"}
-    else QuoteError("foo cannot be called with false")
+    else { qctx.error("foo cannot be called with false"); '{ ??? } }
 
 }

tests/neg-macros/quote-error-2/Macro_1.scala

@@ -2,7 +2,7 @@ import quoted._
 
 object Macro_1 {
   inline def foo(inline b: Boolean): Unit = ${fooImpl(b)}
-  def fooImpl(b: Boolean) given QuoteContext: Expr[Unit] =
+  def fooImpl(b: Boolean) given (qctx: QuoteContext): Expr[Unit] =
     if (b) '{println("foo(true)")}
-    else QuoteError("foo cannot be called with false")
+    else { qctx.error("foo cannot be called with false"); '{ ??? } }
 }

tests/neg-macros/quote-error/Macro_1.scala

@@ -33,7 +33,8 @@ object Lens {
           apply($getter)(setter)
         }
       case _ =>
-        QuoteError("Unsupported syntax. Example: `GenLens[Address](_.streetNumber)`")
+        qctx.error("Unsupported syntax. Example: `GenLens[Address](_.streetNumber)`")
+        '{???}
     }
   }
 }

tests/neg-with-compiler/i5941/macro_1.scala

@@ -39,7 +39,8 @@ object FQuote {
              values.forall(isStringConstant) =>
         values.collect { case Literal(Constant(value: String)) => value }
       case tree =>
-        QuoteError(s"String literal expected, but ${tree.showExtractors} found")
+        qctx.error(s"String literal expected, but ${tree.showExtractors} found")
+        return '{???}
     }
 
     // [a0, ...]: Any*

tests/run-macros/f-interpolation-1/FQuote_1.scala

@@ -21,7 +21,7 @@ object Macro {
     }
   }
 
-  def fooErrorsImpl(parts : Seq[Expr[String]], args: Seq[Expr[Any]], argsExpr: Expr[Seq[Any]]) given QuoteContext= {
+  def fooErrorsImpl(parts0: Seq[Expr[String]], args: Seq[Expr[Any]], argsExpr: Expr[Seq[Any]]) given QuoteContext= {
     val errors = List.newBuilder[Expr[(Boolean, Int, Int, Int, String)]]
     // true if error, false if warning
     // 0 if part, 1 if arg, 2 if strCtx, 3 if args
@@ -67,6 +67,7 @@ object Macro {
         reported = oldReported
       }
     }
+    val parts = parts0.map { case Const(s) => s }
     dotty.internal.StringContextMacro.interpolate(parts.toList, args.toList, argsExpr, reporter) // Discard result
     errors.result().toExprOfList
   }