4 files changed, 18 insertions, 11 deletions
diff --git a/lib/pure/asyncdispatch.nim b/lib/pure/asyncdispatch.nim
index e15fb0851..c924d0a3d 100644
--- a/lib/pure/asyncdispatch.nim
+++ b/lib/pure/asyncdispatch.nim
@@ -733,7 +733,7 @@ when defined(windows) or defined(nimdoc):
 
   proc acceptAddr*(socket: AsyncFD, flags = {SocketFlag.SafeDisconn},
                    inheritable = defined(nimInheritHandles)):
-      owned(Future[tuple[address: string, client: AsyncFD]]) =
+      owned(Future[tuple[address: string, client: AsyncFD]]) {.gcsafe.} =
     ## Accepts a new connection. Returns a future containing the client socket
     ## corresponding to that connection and the remote address of the client.
     ## The future will complete when the connection is successfully accepted.
@@ -800,7 +800,7 @@ when defined(windows) or defined(nimdoc):
 
     var ol = newCustom()
     ol.data = CompletionData(fd: socket, cb:
-      proc (fd: AsyncFD, bytesCount: DWORD, errcode: OSErrorCode) =
+      proc (fd: AsyncFD, bytesCount: DWORD, errcode: OSErrorCode) {.gcsafe.} =
         if not retFuture.finished:
           if errcode == OSErrorCode(-1):
             completeAccept()
diff --git a/lib/pure/json.nim b/lib/pure/json.nim
index 85c3393b2..c831bf85d 100644
--- a/lib/pure/json.nim
+++ b/lib/pure/json.nim
@@ -437,7 +437,7 @@ macro `%*`*(x: untyped): untyped =
   ## `%` for every element.
   result = toJsonImpl(x)
 
-proc `==`*(a, b: JsonNode): bool =
+proc `==`*(a, b: JsonNode): bool {.noSideEffect.} =
   ## Check two nodes for equality
   if a.isNil:
     if b.isNil: return true
@@ -464,12 +464,16 @@ proc `==`*(a, b: JsonNode): bool =
       if a.fields.len != b.fields.len: return false
       for key, val in a.fields:
         if not b.fields.hasKey(key): return false
-        if b.fields[key] != val: return false
+        when defined(nimHasEffectsOf):
+          {.noSideEffect.}:
+            if b.fields[key] != val: return false
+        else:
+          if b.fields[key] != val: return false
       result = true
 
 proc hash*(n: OrderedTable[string, JsonNode]): Hash {.noSideEffect.}
 
-proc hash*(n: JsonNode): Hash =
+proc hash*(n: JsonNode): Hash {.noSideEffect.} =
   ## Compute the hash for a JSON node
   case n.kind
   of JArray:
diff --git a/lib/system/excpt.nim b/lib/system/excpt.nim
index 3e520570f..a71328c14 100644
--- a/lib/system/excpt.nim
+++ b/lib/system/excpt.nim
@@ -354,7 +354,7 @@ var onUnhandledException*: (proc (errorMsg: string) {.
   ## The default is to write a stacktrace to `stderr` and then call `quit(1)`.
   ## Unstable API.
 
-proc reportUnhandledErrorAux(e: ref Exception) {.nodestroy.} =
+proc reportUnhandledErrorAux(e: ref Exception) {.nodestroy, gcsafe.} =
   when hasSomeStackTrace:
     var buf = newStringOfCap(2000)
     if e.trace.len == 0:
@@ -362,7 +362,8 @@ proc reportUnhandledErrorAux(e: ref Exception) {.nodestroy.} =
     else:
       var trace = $e.trace
       add(buf, trace)
-      `=destroy`(trace)
+      {.gcsafe.}:
+        `=destroy`(trace)
     add(buf, "Error: unhandled exception: ")
     add(buf, e.msg)
     add(buf, " [")
@@ -373,7 +374,8 @@ proc reportUnhandledErrorAux(e: ref Exception) {.nodestroy.} =
       onUnhandledException(buf)
     else:
       showErrorMessage2(buf)
-    `=destroy`(buf)
+    {.gcsafe.}:
+      `=destroy`(buf)
   else:
     # ugly, but avoids heap allocations :-)
     template xadd(buf, s, slen) =
@@ -387,7 +389,8 @@ proc reportUnhandledErrorAux(e: ref Exception) {.nodestroy.} =
     if e.trace.len != 0:
       var trace = $e.trace
       add(buf, trace)
-      `=destroy`(trace)
+      {.gcsafe.}:
+        `=destroy`(trace)
     add(buf, "Error: unhandled exception: ")
     add(buf, e.msg)
     add(buf, " [")
@@ -398,7 +401,7 @@ proc reportUnhandledErrorAux(e: ref Exception) {.nodestroy.} =
     else:
       showErrorMessage(buf.addr, L)
 
-proc reportUnhandledError(e: ref Exception) {.nodestroy.} =
+proc reportUnhandledError(e: ref Exception) {.nodestroy, gcsafe.} =
   if unhandledExceptionHook != nil:
     unhandledExceptionHook(e)
   when hostOS != "any":
diff --git a/lib/system/seqs_v2.nim b/lib/system/seqs_v2.nim
index 375eef340..0ac51109e 100644
--- a/lib/system/seqs_v2.nim
+++ b/lib/system/seqs_v2.nim
@@ -73,7 +73,7 @@ proc prepareSeqAdd(len: int; p: pointer; addlen, elemSize, elemAlign: int): poin
         q.cap = newCap
         result = q
 
-proc shrink*[T](x: var seq[T]; newLen: Natural) =
+proc shrink*[T](x: var seq[T]; newLen: Natural) {.tags: [].} =
   when nimvm:
     setLen(x, newLen)
   else: