Version switch displays options used during koch boot

compiler/commands.nim

@@ -50,11 +50,33 @@ proc writeAdvancedUsage(pass: TCmdLinePass) =
                                  CPU[platform.hostCPU].name]) & AdvancedUsage)
     quit(0)
 
+template bootSwitch(name, expr, userString: expr): expr =
+  # Helper to build boot constants, for debugging you can 'echo' the else part.
+  const name = if expr: " " & userString else: ""
+
+bootSwitch(usedAvoidTimeMachine, noTimeMachine, "-d:avoidTimeMachine")
+bootSwitch(usedRelease, defined(release), "-d:release")
+bootSwitch(usedTinyC, hasTinyCBackend, "-d:tinyc")
+bootSwitch(usedGnuReadline, defined(useGnuReadline), "-d:useGnuReadline")
+bootSwitch(usedNativeStacktrace,
+  defined(nativeStackTrace) and nativeStackTraceSupported,
+  "-d:nativeStackTrace")
+bootSwitch(usedNoCaas, defined(noCaas), "-d:noCaas")
+bootSwitch(usedFFI, hasFFI, "-d:useFFI")
+bootSwitch(usedBoehm, defined(boehmgc), "--gc:boehm")
+bootSwitch(usedMarkAndSweep, defined(gcmarkandsweep), "--gc:markAndSweep")
+bootSwitch(usedGenerational, defined(gcgenerational), "--gc:generational")
+bootSwitch(usedNoGC, defined(nogc), "--gc:none")
+
+
 proc writeVersionInfo(pass: TCmdLinePass) = 
   if pass == passCmd1:
     msgWriteln(`%`(HelpMessage, [VersionAsString, 
                                  platform.OS[platform.hostOS].name, 
                                  CPU[platform.hostCPU].name]))
+    msgWriteln("active boot switches:" & usedRelease & usedAvoidTimeMachine &
+      usedTinyC & usedGnuReadline & usedNativeStacktrace & usedNoCaas &
+      usedFFI & usedBoehm & usedMarkAndSweep & usedGenerational & usedNoGC)
     quit(0)
 
 var

compiler/options.nim

@@ -16,7 +16,7 @@ const
   hasFFI* = defined(useFFI)
   newScopeForIf* = true
   useCaas* = not defined(noCaas)
-  noTimeMachine = defined(avoidTimeMachine) and defined(macosx)
+  noTimeMachine* = defined(avoidTimeMachine) and defined(macosx)
 
 type                          # please make sure we have under 32 options
                               # (improves code efficiency a lot!)

lib/system/excpt.nim

@@ -71,7 +71,7 @@ proc popCurrentException {.compilerRtl, inl.} =
 
 # some platforms have native support for stack traces:
 const
-  nativeStackTraceSupported = (defined(macosx) or defined(linux)) and 
+  nativeStackTraceSupported* = (defined(macosx) or defined(linux)) and
                               not nimrodStackTrace
   hasSomeStackTrace = nimrodStackTrace or 
     defined(nativeStackTrace) and nativeStackTraceSupported