fixes #23355; pop optionStack when exiting scopes (#24926)

fixes #23355

Author: ringabout

compiler/ast.nim

@@ -684,6 +684,7 @@ type
     symbols*: TStrTable
     parent*: PScope
     allowPrivateAccess*: seq[PSym] #  # enable access to private fields
+    optionStackLen*: int
 
   PScope* = ref TScope
 

compiler/lookups.nim

@@ -75,10 +75,13 @@ proc addUniqueSym*(scope: PScope, s: PSym): PSym =
 proc openScope*(c: PContext): PScope {.discardable.} =
   result = PScope(parent: c.currentScope,
                   symbols: initStrTable(),
-                  depthLevel: c.scopeDepth + 1)
+                  depthLevel: c.scopeDepth + 1,
+                  optionStackLen: c.optionStack.len)
   c.currentScope = result
 
 proc rawCloseScope*(c: PContext) =
+  if c.currentScope.optionStackLen >= 1:
+    c.optionStack.setLen(c.currentScope.optionStackLen)
   c.currentScope = c.currentScope.parent
 
 proc closeScope*(c: PContext) =

tests/errmsgs/t23355.nim

@@ -0,0 +1,11 @@
+discard """
+  errormsg: "{.pop.} without a corresponding {.push.}"
+"""
+
+block:
+  {.push raises: [].}
+
+proc f() =
+  {.pop.}
+
+proc g() = raise newException(ValueError, "")