Merge pull request #14943 from dos65/bcode_wrap_errors

Better error messages in case of `TooLarge*` exceptions in GenBCode

Author: nicolasstucki

compiler/src/dotty/tools/backend/jvm/GenBCode.scala

@@ -33,6 +33,8 @@ import scala.tools.asm.tree._
 import tpd._
 import StdNames._
 import dotty.tools.io._
+import scala.tools.asm.MethodTooLargeException
+import scala.tools.asm.ClassTooLargeException
 
 class GenBCode extends Phase {
 
@@ -512,7 +514,7 @@ class GenBCodePipeline(val int: DottyBackendInterface, val primitives: DottyPrim
     *    (c) tear down (closing the classfile-writer and clearing maps)
     *
     */
-  def run(t: Tree): Unit = {
+  def run(t: Tree)(using Context): Unit = {
     this.tree = t
 
     // val bcodeStart = Statistics.startTimer(BackendStats.bcodeTimer)
@@ -558,18 +560,29 @@ class GenBCodePipeline(val int: DottyBackendInterface, val primitives: DottyPrim
     *    (c) dequeue one at a time from queue-2, convert it to byte-array,    place in queue-3
     *    (d) serialize to disk by draining queue-3.
     */
-  private def buildAndSendToDisk(needsOutFolder: Boolean) = {
-
-    feedPipeline1()
-    // val genStart = Statistics.startTimer(BackendStats.bcodeGenStat)
-    (new Worker1(needsOutFolder)).run()
-    // Statistics.stopTimer(BackendStats.bcodeGenStat, genStart)
-
-    (new Worker2).run()
-
-    // val writeStart = Statistics.startTimer(BackendStats.bcodeWriteTimer)
-    drainQ3()
-    // Statistics.stopTimer(BackendStats.bcodeWriteTimer, writeStart)
+  private def buildAndSendToDisk(needsOutFolder: Boolean)(using Context) = {
+    try
+      feedPipeline1()
+      // val genStart = Statistics.startTimer(BackendStats.bcodeGenStat)
+      (new Worker1(needsOutFolder)).run()
+      // Statistics.stopTimer(BackendStats.bcodeGenStat, genStart)
+
+      (new Worker2).run()
+
+      // val writeStart = Statistics.startTimer(BackendStats.bcodeWriteTimer)
+      drainQ3()
+      // Statistics.stopTimer(BackendStats.bcodeWriteTimer, writeStart)
+    catch
+      case e: MethodTooLargeException =>
+        val method = 
+          s"${e.getClassName.replaceAll("/", ".")}.${e.getMethodName}"
+        val msg = 
+          s"Generated bytecode for method '$method' is too large. Size: ${e.getCodeSize} bytes. Limit is 64KB" 
+        report.error(msg)
+      case e: ClassTooLargeException =>
+        val msg = 
+          s"Class '${e.getClassName.replaceAll("/", ".")}' is too large. Constant pool size: ${e.getConstantPoolCount}. Limit is 64KB"
+        report.error(msg)
 
   }