3 files changed, 21 insertions, 4 deletions
diff --git a/lib/system/chcks.nim b/lib/system/chcks.nim
index d3651f659..6f4e8ce37 100644
--- a/lib/system/chcks.nim
+++ b/lib/system/chcks.nim
@@ -8,6 +8,7 @@
 #
 
 # Implementation of some runtime checks.
+import system/helpers2
 
 proc raiseRangeError(val: BiggestInt) {.compilerproc, noinline.} =
   when hostOS == "standalone":
@@ -15,6 +16,12 @@ proc raiseRangeError(val: BiggestInt) {.compilerproc, noinline.} =
   else:
     sysFatal(RangeError, "value out of range: ", $val)
 
+proc raiseIndexError3(i, a, b: int) {.compilerproc, noinline.} =
+  sysFatal(IndexError, formatErrorIndexBound(i, a, b))
+
+proc raiseIndexError2(i, n: int) {.compilerproc, noinline.} =
+  sysFatal(IndexError, formatErrorIndexBound(i, n))
+
 proc raiseIndexError() {.compilerproc, noinline.} =
   sysFatal(IndexError, "index out of bounds")
 
@@ -25,7 +32,7 @@ proc chckIndx(i, a, b: int): int =
   if i >= a and i <= b:
     return i
   else:
-    raiseIndexError()
+    raiseIndexError3(i, a, b)
 
 proc chckRange(i, a, b: int): int =
   if i >= a and i <= b:
diff --git a/lib/system/excpt.nim b/lib/system/excpt.nim
index a6da8f5a3..84a1da343 100644
--- a/lib/system/excpt.nim
+++ b/lib/system/excpt.nim
@@ -454,16 +454,21 @@ when not defined(gcDestructors):
     shallowCopy(result, e.trace)
 
 when defined(nimRequiresNimFrame):
-  proc stackOverflow() {.noinline.} =
+  const nimCallDepthLimit {.intdefine.} = 2000
+
+  proc callDepthLimitReached() {.noinline.} =
     writeStackTrace()
-    showErrorMessage("Stack overflow\n")
+    showErrorMessage("Error: call depth limit reached in a debug build (" &
+        $nimCallDepthLimit & " function calls). You can change it with " &
+        "-d:nimCallDepthLimit=<int> but really try to avoid deep " &
+        "recursions instead.\n")
     quitOrDebug()
 
   proc nimFrame(s: PFrame) {.compilerRtl, inl, exportc: "nimFrame".} =
     s.calldepth = if framePtr == nil: 0 else: framePtr.calldepth+1
     s.prev = framePtr
     framePtr = s
-    if s.calldepth == 2000: stackOverflow()
+    if s.calldepth == nimCallDepthLimit: callDepthLimitReached()
 else:
   proc pushFrame(s: PFrame) {.compilerRtl, inl, exportc: "nimFrame".} =
     # XXX only for backwards compatibility
diff --git a/lib/system/helpers2.nim b/lib/system/helpers2.nim
new file mode 100644
index 000000000..1c9e7c068
--- /dev/null
+++ b/lib/system/helpers2.nim
@@ -0,0 +1,5 @@
+template formatErrorIndexBound*[T](i, a, b: T): string =
+  "index out of bounds: (a:" & $a & ") <= (i:" & $i & ") <= (b:" & $b & ") "
+
+template formatErrorIndexBound*[T](i, n: T): string =
+  "index out of bounds: (i:" & $i & ") <= (n:" & $n & ") "