Merge branch 'master' of github.com:Araq/Nimrod

compiler/guards.nim

@@ -187,7 +187,8 @@ proc usefulFact(n: PNode): PNode =
     #   if a:
     #     ...
     # We make can easily replace 'a' by '2 < x' here:
-    result = usefulFact(n.sym.ast)
+    if n.sym.ast != nil:
+      result = usefulFact(n.sym.ast)
   elif n.kind == nkStmtListExpr:
     result = usefulFact(n.lastSon)
 

compiler/sem.nim

@@ -141,21 +141,23 @@ proc semDirectOp(c: PContext, n: PNode, flags: TExprFlags): PNode
 
 proc semWhen(c: PContext, n: PNode, semCheck: bool = true): PNode
 
-proc evalTypedExpr(c: PContext, e: PNode): PNode =
-  result = getConstExpr(c.module, e)
-  if result == nil:
-    result = evalConstExpr(c.module, e)
-    if result == nil or result.kind == nkEmpty:
-      LocalError(e.info, errConstExprExpected)
-      # error correction:
-      result = e
-
 proc semConstExpr(c: PContext, n: PNode): PNode =
   var e = semExprWithType(c, n)
   if e == nil:
     LocalError(n.info, errConstExprExpected)
     return n
-  result = evalTypedExpr(c, e)
+  result = getConstExpr(c.module, e)
+  if result == nil:
+    result = evalConstExpr(c.module, e)
+    if result == nil or result.kind == nkEmpty:
+      if e.info != n.info:
+        pushInfoContext(n.info)
+        LocalError(e.info, errConstExprExpected)
+        popInfoContext()
+      else:
+        LocalError(e.info, errConstExprExpected)
+      # error correction:
+      result = e
 
 include hlo, seminst, semcall
 

compiler/semexprs.nim

@@ -751,8 +751,11 @@ proc semEcho(c: PContext, n: PNode): PNode =
   checkMinSonsLen(n, 1)
   for i in countup(1, sonsLen(n) - 1): 
     var arg = semExprWithType(c, n.sons[i])
-    n.sons[i] = semExpr(c, buildStringify(c, arg))
-  
+    n.sons[i] = semExprWithType(c, buildStringify(c, arg))
+    let t = n.sons[i].typ
+    if t == nil or t.skipTypes(abstractInst).kind != tyString:  
+      LocalError(n.info, errGenerated,
+                 "implicitly invoked '$' does not return string")
   let t = n.sons[0].typ
   if tfNoSideEffect notin t.flags: incl(c.p.owner.flags, sfSideEffect)
   result = n