From ed226eba6dab432ba47f3bb6e4a6b3b1dea64330 Mon Sep 17 00:00:00 2001
From: Araq <rumpf_a@web.de>
Date: Wed, 16 Jul 2014 22:32:09 +0200
Subject: [PATCH] added stack overflow prevention

---
 lib/nimbase.h        |  3 ++-
 lib/system.nim       |  3 ++-
 lib/system/excpt.nim | 29 ++++++++++++++++++-----------
 web/news.txt         |  3 ++-
 4 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/lib/nimbase.h b/lib/nimbase.h
index cfd33dca18..b430942270 100644
--- a/lib/nimbase.h
+++ b/lib/nimbase.h
@@ -328,7 +328,8 @@ struct TFrame {
   NCSTRING procname;
   NI line;
   NCSTRING filename;
-  NI len;
+  NI16 len;
+  NI16 calldepth;
 };
 
 #define nimfr(proc, file) \
diff --git a/lib/system.nim b/lib/system.nim
index 3c42385b78..2fb08563aa 100644
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -2001,7 +2001,8 @@ type
     procname*: cstring  ## name of the proc that is currently executing
     line*: int          ## line number of the proc that is currently executing
     filename*: cstring  ## filename of the proc that is currently executing
-    len*: int           ## length of the inspectable slots
+    len*: int16         ## length of the inspectable slots
+    calldepth*: int16   ## used for max call depth checking
 
 when defined(JS):
   proc add*(x: var string, y: cstring) {.asmNoStackFrame.} =
diff --git a/lib/system/excpt.nim b/lib/system/excpt.nim
index 63a61183f6..e1a5a958fe 100644
--- a/lib/system/excpt.nim
+++ b/lib/system/excpt.nim
@@ -1,7 +1,7 @@
 #
 #
 #            Nimrod's Runtime Library
-#        (c) Copyright 2012 Andreas Rumpf
+#        (c) Copyright 2014 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
@@ -44,16 +44,6 @@ var
     # a global variable for the root of all try blocks
   currException {.rtlThreadVar.}: ref E_Base
 
-when defined(nimRequiresNimFrame):
-  proc nimFrame(s: PFrame) {.compilerRtl, inl, exportc: "nimFrame".} =
-    s.prev = framePtr
-    framePtr = s
-else:
-  proc pushFrame(s: PFrame) {.compilerRtl, inl, exportc: "nimFrame".} =
-    # XXX only for backwards compatibility
-    s.prev = framePtr
-    framePtr = s
-
 proc popFrame {.compilerRtl, inl.} =
   framePtr = framePtr.prev
 
@@ -280,6 +270,23 @@ proc getStackTrace(e: ref E_Base): string =
   else:
     result = ""
 
+when defined(nimRequiresNimFrame):
+  proc stackOverflow() {.noinline.} =
+    writeStackTrace()
+    showErrorMessage("Stack overflow\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()
+else:
+  proc pushFrame(s: PFrame) {.compilerRtl, inl, exportc: "nimFrame".} =
+    # XXX only for backwards compatibility
+    s.prev = framePtr
+    framePtr = s
+
 when defined(endb):
   var
     dbgAborting: bool # whether the debugger wants to abort
diff --git a/web/news.txt b/web/news.txt
index a8d525443f..a913c94ad7 100644
--- a/web/news.txt
+++ b/web/news.txt
@@ -16,7 +16,8 @@ News
     now considered for implicit early binding.
   - ``c2nim`` moved into its own repository and is now a Babel package.
   - ``pas2nim`` moved into its own repository and is now a Babel package.
-
+  - ``system.$`` for floating point types now produces a human friendly string
+    representation.
 
   Library Additions
   -----------------