note plan for pragma.singlePragma

- this is the next "big" nkError thing to fix
- see plan in the new proc `prepareSinglePragma`

compiler/pragmas.nim

@@ -335,7 +335,7 @@ proc processDynLib(c: PContext, n: PNode, sym: PSym) =
 proc processNote(c: PContext, n: PNode) =
   template handleNote(enumVals, notes) =
     let x = findStr(enumVals.a, enumVals.b, n[0][1].ident.s, errUnknown)
-    if x !=  errUnknown:
+    if x != errUnknown:
       nk = TNoteKind(x)
       let x = c.semConstBoolExpr(c, n[1])
       n[1] = x
@@ -762,8 +762,10 @@ proc semCustomPragma(c: PContext, n: PNode): PNode =
   elif n.kind in nkPragmaCallKinds:
     callNode = n
   else:
-    invalidPragma(c, n)
-    return n
+    result = newError(c, n, InvalidPragma)
+    return
+    # invalidPragma(c, n)
+    # return n
 
   let r = c.semOverloadedCall(c, callNode, n, {skTemplate}, {efNoUndeclared})
   if r.isNil or sfCustomPragma notin r[0].sym.flags:
@@ -801,6 +803,20 @@ proc processEffectsOf(c: PContext, n: PNode; owner: PSym) =
     else:
       processParam(c, it)
 
+proc prepareSinglePragma(
+    c: PContext; sym: PSym, n: PNode, i: var int, validPragmas: TSpecialWords,
+    comesFromPush, isStatement: bool
+  ): PNode =
+  ## xxx: implement me, replacing `singlePragma`:
+  ##      - return nil if not a single pragma
+  ##      - return an nkError if `invalidPragma` would have been called
+  ##      - return the pragma after prep and it's good to go
+  ##      - all the localErrors and what not should be nkErrors
+  ##      - see if there is a better name than `prepareSinglePragma`
+  ##      - replace all usages of `singlePragma`
+  ##      - have a nice day
+  result = nil
+
 proc singlePragma(c: PContext, sym: PSym, n: PNode, i: var int,
                   validPragmas: TSpecialWords,
                   comesFromPush, isStatement: bool): bool =
@@ -1313,8 +1329,7 @@ proc pragma(c: PContext, sym: PSym, n: PNode, validPragmas: TSpecialWords;
   # XXX: in the case of a callable def, this should use its info
   implicitPragmas(c, sym, n.info, validPragmas)
 
-proc pragmaCallable*(c: PContext, sym: PSym, n: PNode, validPragmas: TSpecialWords,
-                    isStatement: bool = false) =
+proc pragmaCallable*(c: PContext, sym: PSym, n: PNode, validPragmas: TSpecialWords) =
   if n == nil: return
   if n[pragmasPos].kind != nkEmpty:
-    pragmaRec(c, sym, n[pragmasPos], validPragmas, isStatement)
+    pragmaRec(c, sym, n[pragmasPos], validPragmas, false)