optimizations for system.compiles

compiler/semcall.nim

@@ -69,6 +69,10 @@ proc resolveOverloads(c: PContext, n, orig: PNode,
       InternalError(n.info, "x.state is not csMatch")
     #writeMatches(best)
     #writeMatches(alt)
+    if c.inCompilesContext > 0: 
+      # quick error message for performance of 'compiles' built-in:
+      LocalError(n.Info, errAmbiguousCallXYZ, "")
+    else:
       var args = "("
       for i in countup(1, sonsLen(n) - 1):
         if i > 1: add(args, ", ")

compiler/semexprs.nim

@@ -608,6 +608,10 @@ proc semIndirectOp(c: PContext, n: PNode, flags: TExprFlags): PNode =
     initCandidate(m, t)
     matches(c, n, nOrig, m)
     if m.state != csMatch:
+      if c.inCompilesContext > 0:
+        # speed up error generation:
+        GlobalError(n.Info, errTypeMismatch, "")
+      else:
         var msg = msgKindToString(errTypeMismatch)
         for i in countup(1, sonsLen(n) - 1): 
           if i > 1: add(msg, ", ")

compiler/sigmatch.nim

@@ -118,6 +118,7 @@ proc getNotFoundError*(c: PContext, n: PNode): string =
   # Gives a detailed error message; this is separated from semOverloadedCall,
   # as semOverlodedCall is already pretty slow (and we need this information
   # only in case of an error).
+  if c.InCompilesContext > 0: return ""
   result = msgKindToString(errTypeMismatch)
   for i in countup(1, sonsLen(n) - 1): 
     #debug(n.sons[i].typ)