Handle stackoverflows when trying to print the maximal constraint

odersky · odersky · commit 149b433849d0 · 2022-09-02T12:05:41.000+02:00
diff --git a/compiler/src/dotty/tools/dotc/core/ConstraintRunInfo.scala b/compiler/src/dotty/tools/dotc/core/ConstraintRunInfo.scala
@@ -13,9 +13,12 @@ trait ConstraintRunInfo { self: Run =>
       maxConstraint = c
     }
   def printMaxConstraint()(using Context): Unit =
-    val printer = if (ctx.settings.YdetailedStats.value) default else typr
     if maxSize > 0 then
-      printer.println(s"max constraint = ${maxConstraint.nn.show}\nsize = $maxSize")
+      val printer = if ctx.settings.YdetailedStats.value then default else typr
+      val maxc = maxConstraint.nn
+      val maxcStr = try maxc.show catch case ex: StackOverflowError => maxc.toString
+      printer.println(s"max constraint size: $maxSize")
+      printer.println(s"max constraint = $maxcStr")
 
   protected def reset(): Unit = maxConstraint = null
 }

Original file line number	Diff line number	Diff line change
`@@ -13,9 +13,12 @@ trait ConstraintRunInfo { self: Run =>`
`13`	`13`	`maxConstraint = c`
`14`	`14`	`}`
`15`	`15`	`def printMaxConstraint()(using Context): Unit =`
`16`		`- val printer = if (ctx.settings.YdetailedStats.value) default else typr`
`17`	`16`	`if maxSize > 0 then`
`18`		`- printer.println(s"max constraint = ${maxConstraint.nn.show}\nsize = $maxSize")`
	`17`	`+ val printer = if ctx.settings.YdetailedStats.value then default else typr`
	`18`	`+ val maxc = maxConstraint.nn`
	`19`	`+ val maxcStr = try maxc.show catch case ex: StackOverflowError => maxc.toString`
	`20`	`+ printer.println(s"max constraint size: $maxSize")`
	`21`	`+ printer.println(s"max constraint = $maxcStr")`
`19`	`22`
`20`	`23`	`protected def reset(): Unit = maxConstraint = null`
`21`	`24`	`}`