Fix a bug when type casting on unresolved types

nelua/analyzer.lua

@@ -899,7 +899,6 @@ local function visitor_Call_type_cast(context, node, argnodes, type)
       type, #argnodes)
   end
   local argnode = argnodes[1]
-  local done = true
   if argnode then
     argnode.desiredtype = type
     context:traverse_node(argnode)
@@ -924,17 +923,19 @@ local function visitor_Call_type_cast(context, node, argnodes, type)
           attr.comptime = true
         end
       end
+      attr.type = type
+      attr.calleetype = primtypes.type
+      attr.sideeffect = argnode.attr.sideeffect
+      attr.lvalue = argnode.attr.lvalue
+      if argnode.done then
+        node.done = true
+      end
     end
-    attr.sideeffect = argnode.attr.sideeffect
-    attr.lvalue = argnode.attr.lvalue
-    if not argnode.done then
-      done = nil
-    end
+  else -- zero initializer
+    attr.type = type
+    attr.calleetype = primtypes.type
+    node.done = true
   end
-  attr.typecast = true
-  attr.type = type
-  attr.calleetype = primtypes.type
-  node.done = done
 end
 
 local function visitor_Call(context, node, argnodes, calleetype, calleesym, calleeobjnode)

spec/03-typechecker_spec.lua

@@ -1458,6 +1458,14 @@ it("type construction", function()
   assert.analyze_error("local a = (@integer)(nil)", "no viable type conversion")
 end)
 
+it("type casting", function()
+  assert.analyze_error([[
+    local R = @record{}
+    local a = 'b'
+    local b = (@R)(a)
+  ]], "no viable type conversion")
+end)
+
 it("annotations", function()
   assert.analyze_ast("local r: record{x: integer} <aligned(8)>")
   assert.analyze_ast("local Record <aligned(8)> = @record{x: integer}")

tests/string_test.nelua

@@ -24,6 +24,31 @@ do -- initialization, len, eq and reset
   assert('a' == 'a')
 end
 
+do -- casting
+  local sstr = (@string)("hello")
+  local scstr = (@cstring)("hello")
+  local svstr = (@stringview)("hello")
+  local dstr: string
+  local dcstr: cstring
+  local dvstr: stringview
+
+  -- implicit
+  dstr = scstr assert(dstr == "hello")   -- cstring -> string
+  dstr = svstr assert(dstr == "hello")   -- stringview -> string
+  dcstr = sstr assert(dcstr == "hello")  -- string -> cstring
+  dcstr = svstr assert(dcstr == "hello") -- stringview -> cstring
+  dvstr = scstr assert(dvstr == "hello") -- cstring -> stringview
+  dvstr = sstr assert(dvstr == "hello")  -- string -> stringview
+
+  -- explicit
+  dstr = (@string)(scstr) assert(dstr == "hello")       -- cstring -> string
+  dstr = (@string)(svstr) assert(dstr == "hello")       -- stringview -> string
+  dcstr = (@cstring)(sstr) assert(dcstr == "hello")     -- string -> cstring
+  dcstr = (@cstring)(svstr) assert(dcstr == "hello")    -- stringview -> cstring
+  dvstr = (@stringview)(scstr) assert(dvstr == "hello") -- cstring -> stringview
+  dvstr = (@stringview)(sstr) assert(dvstr == "hello")  -- string -> stringview
+end
+
 do -- len
   local a: string = 'hello'
   local e: string