Raise compile errors on bad binary types

Both size and unit must be non-negative integers.

These checks were previously performed by erl_lint.

Author: fertapric

lib/elixir/lib/kernel/typespec.ex

@@ -449,13 +449,13 @@ defmodule Kernel.Typespec do
          _,
          state
        )
-       when is_atom(ctx1) and is_atom(ctx2) and is_integer(unit) do
+       when is_atom(ctx1) and is_atom(ctx2) and is_integer(unit) and unit >= 0 do
     line = line(meta)
     {{:type, line, :binary, [{:integer, line, 0}, {:integer, line(unit_meta), unit}]}, state}
   end
 
   defp typespec({:<<>>, meta, [{:::, size_meta, [{:_, _, ctx}, size]}]}, _, _, state)
-       when is_atom(ctx) and is_integer(size) do
+       when is_atom(ctx) and is_integer(size) and size >= 0 do
     line = line(meta)
     {{:type, line, :binary, [{:integer, line(size_meta), size}, {:integer, line, 0}]}, state}
   end
@@ -474,11 +474,19 @@ defmodule Kernel.Typespec do
          state
        )
        when is_atom(ctx1) and is_atom(ctx2) and is_atom(ctx3) and is_integer(size) and
-              is_integer(unit) do
+              is_integer(unit) and size >= 0 and unit >= 0 do
     args = [{:integer, line(size_meta), size}, {:integer, line(unit_meta), unit}]
     {{:type, line(meta), :binary, args}, state}
   end
 
+  defp typespec({:<<>>, _meta, _args}, _vars, caller, _state) do
+    message =
+      "invalid binary specification, expected <<_::size>>, <<_::_*unit>>, " <>
+        "or <<_::size, _::_*unit>> with size and unit being non-negative integers"
+
+    compile_error(caller, message)
+  end
+
   ## Handle maps and structs
   defp typespec({:map, meta, args}, _vars, _caller, state) when args == [] or is_atom(args) do
     {{:type, line(meta), :map, :any}, state}

lib/elixir/test/elixir/typespec_test.exs

@@ -367,11 +367,35 @@ defmodule TypespecTest do
     end
 
     test "@type with invalid binary spec" do
-      assert_raise CompileError, fn ->
+      assert_raise CompileError, ~r"invalid binary specification", fn ->
         test_module do
           @type my_type :: <<_::3*8>>
         end
       end
+
+      assert_raise CompileError, ~r"invalid binary specification", fn ->
+        test_module do
+          @type my_type :: <<_::atom>>
+        end
+      end
+
+      assert_raise CompileError, ~r"invalid binary specification", fn ->
+        test_module do
+          @type my_type :: <<_::(-4)>>
+        end
+      end
+
+      assert_raise CompileError, ~r"invalid binary specification", fn ->
+        test_module do
+          @type my_type :: <<_::3, _::_*atom>>
+        end
+      end
+
+      assert_raise CompileError, ~r"invalid binary specification", fn ->
+        test_module do
+          @type my_type :: <<_::3, _::_*(-8)>>
+        end
+      end
     end
 
     test "@type with a range op" do