Fixed and slightly changed exception handling.

lib/system/jssys.nim

@@ -37,9 +37,6 @@ type
 
 var
   framePtr {.importc, nodecl, volatile.}: PCallFrame
-  excHandler {.importc, nodecl, volatile.}: PSafePoint = nil
-    # list of exception handlers
-    # a global variable for the root of all try blocks
   lastJSError {.importc, nodecl, volatile.}: PJSError = nil
 
 {.push stacktrace: off, profiler:off.}
@@ -52,9 +49,7 @@ proc nimCharToStr(x: char): string {.compilerproc.} =
   result[0] = x
 
 proc getCurrentExceptionMsg*(): string =
-  if excHandler != nil and excHandler.exc != nil:
-    return $excHandler.exc.msg
-  elif lastJSError != nil:
+  if lastJSError != nil:
     return $lastJSError.message
   else:
     return ""
@@ -102,29 +97,13 @@ proc rawWriteStackTrace(): string =
 proc raiseException(e: ref Exception, ename: cstring) {.
     compilerproc, asmNoStackFrame.} =
   e.name = ename
-  if excHandler != nil:
-    excHandler.exc = e
-  else:
-    when NimStackTrace:
-      var buf = rawWriteStackTrace()
-    else:
-      var buf = ""
-    if e.msg != nil and e.msg[0] != '\0':
-      add(buf, "Error: unhandled exception: ")
-      add(buf, e.msg)
-    else:
-      add(buf, "Error: unhandled exception")
-    add(buf, " [")
-    add(buf, ename)
-    add(buf, "]\n")
-    alert(buf)
-  asm """throw `e`;"""
+  asm "throw `e`;"
 
 proc reraiseException() {.compilerproc, asmNoStackFrame.} =
-  if excHandler == nil:
+  if lastJSError == nil:
     raise newException(ReraiseError, "no exception to reraise")
   else:
-    asm """throw excHandler.exc;"""
+    asm "throw lastJSError;"
 
 proc raiseOverflow {.exportc: "raiseOverflow", noreturn.} =
   raise newException(OverflowError, "over- or underflow")