fix for passing tuples as static params to macros (#11423); fixes #10751 [bugfix]

* add vm value preparation proc

* small optimization

compiler/vm.nim

@@ -2031,12 +2031,29 @@ proc evalStaticStmt*(module: PSym; g: ModuleGraph; e: PNode, prc: PSym) =
 proc setupCompileTimeVar*(module: PSym; g: ModuleGraph; n: PNode) =
   discard evalConstExprAux(module, g, nil, n, emStaticStmt)
 
+proc prepareVMValue(arg: PNode): PNode =
+  ## strip nkExprColonExpr from tuple values recurively. That is how
+  ## they are expected to be stored in the VM.
+
+  # Early abort without copy. No transformation takes place.
+  if arg.kind in nkLiterals:
+    return arg
+
+  result = copyNode(arg)
+  if arg.kind == nkTupleConstr:
+    for child in arg:
+      if child.kind == nkExprColonExpr:
+        result.add prepareVMValue(child[1])
+      else:
+        result.add prepareVMValue(child)
+  else:
+    for child in arg:
+      result.add prepareVMValue(child)
+
 proc setupMacroParam(x: PNode, typ: PType): TFullReg =
   case typ.kind
   of tyStatic:
-    putIntoReg(result, x)
-  #of tyTypeDesc:
-  #  putIntoReg(result, x)
+    putIntoReg(result, prepareVMValue(x))
   else:
     result.kind = rkNode
     var n = x

tests/macros/tmacros1.nim

@@ -49,3 +49,15 @@ myEnums = enumerators2()
 echo myEnums
 myEnums = enumerators3()
 echo myEnums
+
+#10751
+
+type Tuple = tuple
+  a: string
+  b: int
+
+macro foo(t: static Tuple): untyped =
+  doAssert t.a == "foo"
+  doAssert t.b == 12345
+
+foo((a: "foo", b: 12345))