reintroduce thread analysis but disable it for backwards compatibility

compiler/commands.nim

@@ -168,6 +168,7 @@ proc testCompileOption*(switch: string, info: TLineInfo): bool =
   of "forcebuild", "f": result = contains(gGlobalOptions, optForceFullMake)
   of "warnings", "w": result = contains(gOptions, optWarns)
   of "hints": result = contains(gOptions, optHints)
+  of "threadanalysis": result = contains(gGlobalOptions, optThreadAnalysis)
   of "stacktrace": result = contains(gOptions, optStackTrace)
   of "linetrace": result = contains(gOptions, optLineTrace)
   of "debugger": result = contains(gOptions, optEndb)
@@ -329,6 +330,7 @@ proc processSwitch(switch, arg: string, pass: TCmdLinePass, info: TLineInfo) =
   of "warning": processSpecificNote(arg, wWarning, pass, info)
   of "hint": processSpecificNote(arg, wHint, pass, info)
   of "hints": processOnOffSwitch({optHints}, arg, pass, info)
+  of "threadanalysis": processOnOffSwitchG({optThreadAnalysis}, arg, pass, info)
   of "stacktrace": processOnOffSwitch({optStackTrace}, arg, pass, info)
   of "linetrace": processOnOffSwitch({optLineTrace}, arg, pass, info)
   of "debugger": 

compiler/lowerings.nim

@@ -12,7 +12,7 @@
 const
   genPrefix* = ":tmp"         # prefix for generated names
 
-import ast, astalgo, types, idents, magicsys, msgs
+import ast, astalgo, types, idents, magicsys, msgs, options
 
 proc newTupleAccess*(tup: PNode, i: int): PNode =
   result = newNodeIT(nkBracketExpr, tup.info, tup.typ.skipTypes(
@@ -151,6 +151,7 @@ proc wrapProcForSpawn*(owner: PSym; n: PNode): PNode =
   if n.kind notin nkCallKinds or not n.typ.isEmptyType:
     localError(n.info, "'spawn' takes a call expression of type void")
     return
+  if optThreadAnalysis in gGlobalOptions:
     if {tfThread, tfNoSideEffect} * n[0].typ.flags == {}:
       localError(n.info, "'spawn' takes a GC safe call expression")
   var

compiler/options.nim

@@ -60,6 +60,7 @@ type                          # please make sure we have under 32 options
     optContext,               # ideTools: 'context'
     optDef,                   # ideTools: 'def'
     optUsages,                # ideTools: 'usages'
+    optThreadAnalysis,        # thread analysis pass
     optTaintMode,             # taint mode turned on
     optTlsEmulation,          # thread var emulation turned on
     optGenIndex               # generate index file for documentation;

compiler/pragmas.nim

@@ -1,7 +1,7 @@
 #
 #
 #           The Nimrod Compiler
-#        (c) Copyright 2012 Andreas Rumpf
+#        (c) Copyright 2014 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
@@ -689,6 +689,7 @@ proc singlePragma(c: PContext, sym: PSym, n: PNode, i: int,
           incl(sym.flags, sfProcvar)
           if sym.typ != nil: incl(sym.typ.flags, tfThread)
         of wGcSafe:
+          if optThreadAnalysis in gGlobalOptions:
             noVal(it)
             if sym.kind != skType: incl(sym.flags, sfThread)
             if sym.typ != nil: incl(sym.typ.flags, tfGcSafe)

compiler/sempass2.nim

@@ -705,6 +705,7 @@ proc trackProc*(s: PSym, body: PNode) =
       checkRaisesSpec(usesSpec, t.uses,
         "uses an unlisted global variable: ", hints=on, symbolPredicate)
       effects.sons[usesEffects] = usesSpec
+  if optThreadAnalysis in gGlobalOptions:
     if sfThread in s.flags and t.gcUnsafe:
       localError(s.info, warnGcUnsafe2, s.name.s)
       #localError(s.info, "'$1' is not GC-safe" % s.name.s)

doc/advopt.txt

@@ -63,6 +63,7 @@ Advanced options:
   --lineDir:on|off          generation of #line directive on|off
   --embedsrc                embeds the original source code as comments
                             in the generated output
+  --threadanalysis:on|off   turn thread analysis on|off
   --tlsEmulation:on|off     turn thread local storage emulation on|off
   --taintMode:on|off        turn taint mode on|off
   --symbolFiles:on|off      turn symbol files on|off (experimental)

lib/pure/osproc.nim

@@ -615,11 +615,13 @@ elif not defined(useNimRtl):
     optionPoStdErrToStdOut: bool
 
   when not defined(useFork):
-    proc startProcessAuxSpawn(data: TStartProcessData): TPid {.tags: [FExecIO, FReadEnv].}
+    proc startProcessAuxSpawn(data: TStartProcessData): TPid {.
-  proc startProcessAuxFork(data: TStartProcessData): TPid {.tags: [FExecIO, FReadEnv].}
+      tags: [FExecIO, FReadEnv], gcsafe.}
+  proc startProcessAuxFork(data: TStartProcessData): TPid {.
+    tags: [FExecIO, FReadEnv], gcsafe.}
   {.push stacktrace: off, profiler: off.}
   proc startProcessAfterFork(data: ptr TStartProcessData) {.
-    tags: [FExecIO, FReadEnv], cdecl.}
+    tags: [FExecIO, FReadEnv], cdecl, gcsafe.}
   {.pop.}
 
   proc startProcess(command: string,
@@ -946,7 +948,7 @@ elif not defined(useNimRtl):
 proc execCmdEx*(command: string, options: set[TProcessOption] = {
                 poStdErrToStdOut, poUsePath}): tuple[
                 output: TaintedString,
-                exitCode: int] {.tags: [FExecIO, FReadIO].} =
+                exitCode: int] {.tags: [FExecIO, FReadIO], gcsafe.} =
   ## a convenience proc that runs the `command`, grabs all its output and
   ## exit code and returns both.
   var p = startCmd(command, options)