Stop propagating generated on macro arguments (#14696)

* Stop propagating generated on macro arguments

* Explicitly mark assert as generated

Author: sabiwara

lib/elixir/lib/macro/env.ex

@@ -657,7 +657,7 @@ defmodule Macro.Env do
         :elixir_dispatch.check_deprecated(:macro, meta, receiver, name, arity, env)
       end
 
-      quoted = expander.(args, env)
+      quoted = expander.(:elixir_dispatch.stop_generated(args), env)
       next = :elixir_module.next_counter(env.module)
       :elixir_quote.linify_with_context_counter(expansion_meta, {receiver, next}, quoted)
     end

lib/elixir/src/elixir_dispatch.erl

@@ -10,7 +10,7 @@
   require_function/5, import_function/4,
   expand_import/7, expand_require/6, check_deprecated/6,
   default_functions/0, default_macros/0, default_requires/0,
-  find_import/4, find_imports/3, format_error/1]).
+  find_import/4, find_imports/3, format_error/1, stop_generated/1]).
 -include("elixir.hrl").
 -import(ordsets, [is_element/2]).
 -define(kernel, 'Elixir.Kernel').
@@ -119,7 +119,7 @@ dispatch_import(Meta, Name, Args, S, E, Callback) ->
     {macro, Receiver, Expander} ->
       check_deprecated(macro, Meta, Receiver, Name, Arity, E),
       Caller = {?line(Meta), S, E},
-      expand_quoted(Meta, Receiver, Name, Arity, Expander(Args, Caller), S, E);
+      expand_quoted(Meta, Receiver, Name, Arity, Expander(stop_generated(Args), Caller), S, E);
     {function, Receiver, NewName} ->
       case elixir_rewrite:inline(Receiver, NewName, Arity) of
         {AR, AN} ->
@@ -134,6 +134,12 @@ dispatch_import(Meta, Name, Args, S, E, Callback) ->
       elixir_errors:file_error(Meta, E, ?MODULE, {import, Error, Name, Arity})
   end.
 
+stop_generated(Args) ->
+  lists:map(fun
+    ({Call, Meta, Ctx}) when is_list(Meta) -> {Call, [{stop_generated, true} | Meta], Ctx};
+    (Other) -> Other
+  end, Args).
+
 dispatch_require(Meta, Receiver, Name, Args, S, E, Callback) when is_atom(Receiver) ->
   Arity = length(Args),
 

lib/elixir/src/elixir_quote.erl

@@ -9,7 +9,7 @@
 -include("elixir.hrl").
 -define(defs(Kind), Kind == def; Kind == defp; Kind == defmacro; Kind == defmacrop; Kind == '@').
 -define(lexical(Kind), Kind == import; Kind == alias; Kind == require).
--compile({inline, [keyfind/2, keystore/3, keydelete/2, keynew/3, do_tuple_linify/5]}).
+-compile({inline, [keyfind/2, keystore/3, keydelete/2, keynew/3, do_tuple_linify/6]}).
 
 -record(elixir_quote, {
   line=false,
@@ -84,53 +84,58 @@ linify(Line, Key, Exprs) when is_integer(Line) ->
         end
     end,
 
-  do_linify(Fun, Exprs, nil).
+  do_linify(Fun, Exprs, nil, false).
 
 %% Same as linify but also considers the context counter and generated.
 linify_with_context_counter(ContextMeta, Var, Exprs) when is_list(ContextMeta) ->
   Line = ?line(ContextMeta),
 
-  Fun =
-    case lists:keyfind(generated, 1, ContextMeta) of
-      {generated, true} when Line =:= 0 -> fun elixir_utils:generated/1;
-      {generated, true} -> fun(Meta) -> elixir_utils:generated(keynew(line, Meta, Line)) end;
-      _ when Line =:= 0 -> fun(Meta) -> Meta end;
-      _ -> fun(Meta) -> keynew(line, Meta, Line) end
-    end,
+  Generated = keyfind(generated, ContextMeta) == {generated, true},
+
+  Fun = if
+    Line =:= 0 -> fun(Meta) -> Meta end;
+    true -> fun(Meta) -> keynew(line, Meta, Line) end
+  end,
 
-  do_linify(Fun, Exprs, Var).
+  do_linify(Fun, Exprs, Var, Generated).
 
-do_linify(Fun, {quote, Meta, [_ | _] = Args}, {Receiver, Counter} = Var)
+do_linify(Fun, {quote, Meta, [_ | _] = Args}, {Receiver, Counter} = Var, Gen)
     when is_list(Meta) ->
   NewMeta =
     case keyfind(context, Meta) == {context, Receiver} of
       true -> keynew(counter, Meta, Counter);
       false -> Meta
     end,
-  do_tuple_linify(Fun, NewMeta, quote, Args, Var);
+  do_tuple_linify(Fun, NewMeta, quote, Args, Var, Gen);
 
-do_linify(Fun, {Left, Meta, Receiver}, {Receiver, Counter} = Var)
+do_linify(Fun, {Left, Meta, Receiver}, {Receiver, Counter} = Var, Gen)
     when is_atom(Left), is_list(Meta), Left /= '_' ->
-  do_tuple_linify(Fun, keynew(counter, Meta, Counter), Left, Receiver, Var);
+  do_tuple_linify(Fun, keynew(counter, Meta, Counter), Left, Receiver, Var, Gen);
 
-do_linify(Fun, {Lexical, Meta, [_ | _] = Args}, {_, Counter} = Var)
+do_linify(Fun, {Lexical, Meta, [_ | _] = Args}, {_, Counter} = Var, Gen)
     when ?lexical(Lexical); Lexical == '__aliases__' ->
-  do_tuple_linify(Fun, keynew(counter, Meta, Counter), Lexical, Args, Var);
+  do_tuple_linify(Fun, keynew(counter, Meta, Counter), Lexical, Args, Var, Gen);
+
+do_linify(Fun, {Left, Meta, Right}, Var, Gen) when is_list(Meta) ->
+  do_tuple_linify(Fun, Meta, Left, Right, Var, Gen);
 
-do_linify(Fun, {Left, Meta, Right}, Var) when is_list(Meta) ->
-  do_tuple_linify(Fun, Meta, Left, Right, Var);
+do_linify(Fun, {Left, Right}, Var, Gen) ->
+  {do_linify(Fun, Left, Var, Gen), do_linify(Fun, Right, Var, Gen)};
 
-do_linify(Fun, {Left, Right}, Var) ->
-  {do_linify(Fun, Left, Var), do_linify(Fun, Right, Var)};
+do_linify(Fun, List, Var, Gen) when is_list(List) ->
+  [do_linify(Fun, X, Var, Gen) || X <- List];
 
-do_linify(Fun, List, Var) when is_list(List) ->
-  [do_linify(Fun, X, Var) || X <- List];
+do_linify(_, Else, _, _Gen) -> Else.
 
-do_linify(_, Else, _) -> Else.
+do_tuple_linify(Fun, Meta, Left, Right, Var, Gen) ->
+  {NewMeta, NewGen} =
+    case keyfind(stop_generated, Meta) of
+      {stop_generated, true} -> {keydelete(stop_generated, Meta), false};
+      _ when Gen -> {elixir_utils:generated(Meta), Gen};
+      _ -> {Meta, Gen}
+    end,
 
--compile({inline, do_tuple_linify/5}).
-do_tuple_linify(Fun, Meta, Left, Right, Var) ->
-  {do_linify(Fun, Left, Var), Fun(Meta), do_linify(Fun, Right, Var)}.
+  {do_linify(Fun, Left, Var, NewGen), Fun(NewMeta), do_linify(Fun, Right, Var, NewGen)}.
 
 %% Escaping
 

lib/elixir/test/elixir/macro/env_test.exs

@@ -4,7 +4,9 @@
 Code.require_file("../test_helper.exs", __DIR__)
 
 defmodule MacroEnvMacros do
-  defmacro my_macro(arg), do: arg
+  defmacro my_macro(arg) do
+    quote do: foo(unquote(arg))
+  end
 
   @deprecated "this is deprecated"
   defmacro my_deprecated_macro(arg), do: arg
@@ -154,9 +156,15 @@ defmodule Macro.EnvTest do
 
     test "expands with argument" do
       {:macro, MacroEnvMacros, fun} = expand_require(env(), meta(), MacroEnvMacros, :my_macro, 1)
-      assert fun.([], [quote(do: hello())]) == quote(do: hello())
-      assert fun.([line: 789], [quote(do: hello())]) == quote(line: 789, do: hello())
-      assert fun.([generated: true], [quote(do: hello())]) == quote(generated: true, do: hello())
+      assert fun.([], [quote(do: hello())]) == quote(do: foo(hello()))
+      assert fun.([line: 789], [quote(do: hello())]) == quote(line: 789, do: foo(hello()))
+
+      # do not propagate generated: true to arguments
+      assert {:foo, outer_meta, [{:hello, inner_meta, []}]} =
+               fun.([generated: true], [quote(do: hello())])
+
+      assert outer_meta[:generated]
+      refute inner_meta[:generated]
     end
 
     test "with tracing and deprecations" do
@@ -202,9 +210,15 @@ defmodule Macro.EnvTest do
 
     test "expands with argument" do
       {:macro, MacroEnvMacros, fun} = expand_import(env(), meta(), :my_macro, 1)
-      assert fun.([], [quote(do: hello())]) == quote(do: hello())
-      assert fun.([line: 789], [quote(do: hello())]) == quote(line: 789, do: hello())
-      assert fun.([generated: true], [quote(do: hello())]) == quote(generated: true, do: hello())
+      assert fun.([], [quote(do: hello())]) == quote(do: foo(hello()))
+      assert fun.([line: 789], [quote(do: hello())]) == quote(line: 789, do: foo(hello()))
+
+      # do not propagate generated: true to arguments
+      assert {:foo, outer_meta, [{:hello, inner_meta, []}]} =
+               fun.([generated: true], [quote(do: hello())])
+
+      assert outer_meta[:generated]
+      refute inner_meta[:generated]
     end
 
     defmacro allow_locals_example, do: :ok

lib/elixir/test/elixir/macro_test.exs

@@ -264,7 +264,7 @@ defmodule MacroTest do
       assert Macro.expand_once(expr, __ENV__) == expr
     end
 
-    test "propagates generated" do
+    test "propagates :generated" do
       assert {:||, meta, [1, false]} = Macro.expand_once(quote(do: oror(1, false)), __ENV__)
       refute meta[:generated]
 
@@ -274,6 +274,41 @@ defmodule MacroTest do
       assert meta[:generated]
     end
 
+    test "does not propagate :generated to unquoted" do
+      non_generated = quote do: foo()
+
+      assert {:||, outer_meta, [{:foo, inner_meta, []}, false]} =
+               Macro.expand_once(
+                 quote generated: true do
+                   oror(unquote(non_generated), false)
+                 end,
+                 __ENV__
+               )
+
+      assert outer_meta[:generated]
+      refute inner_meta[:generated]
+    end
+
+    defmacro foo_bar(x) do
+      y = quote do: bar(unquote(x))
+
+      quote do: foo(unquote(y))
+    end
+
+    test "propagates :generated to unquote within macro" do
+      non_generated = quote do: baz()
+
+      assert {:foo, foo_meta, [{:bar, bar_meta, [{:baz, baz_meta, []}]}]} =
+               Macro.expand_once(
+                 quote(generated: true, do: foo_bar(unquote(non_generated))),
+                 __ENV__
+               )
+
+      assert foo_meta[:generated]
+      assert bar_meta[:generated]
+      refute baz_meta[:generated]
+    end
+
     test "does not expand module attributes" do
       message =
         "could not call Module.get_attribute/2 because the module #{inspect(__MODULE__)} " <>

lib/ex_unit/lib/ex_unit/assertions.ex

@@ -133,7 +133,7 @@ defmodule ExUnit.Assertions do
 
   """
   defmacro assert({:=, meta, [left, right]} = assertion) do
-    code = escape_quoted(:assert, meta, assertion)
+    code = escape_quoted(:assert, meta, mark_as_generated(assertion))
 
     check =
       quote generated: true do
@@ -150,7 +150,7 @@ defmodule ExUnit.Assertions do
   end
 
   defmacro assert({:match?, meta, [left, right]} = assertion) do
-    code = escape_quoted(:assert, meta, assertion)
+    code = escape_quoted(:assert, meta, mark_as_generated(assertion))
     match? = {:match?, meta, [left, Macro.var(:right, __MODULE__)]}
 
     left = __expand_pattern__(left, __CALLER__)
@@ -727,10 +727,13 @@ defmodule ExUnit.Assertions do
 
   defp has_var?(pattern, name, context), do: Enum.any?(pattern, &match?({^name, _, ^context}, &1))
 
-  defp mark_as_generated(vars) do
-    for {name, meta, context} <- vars, do: {name, [generated: true] ++ meta, context}
+  defp mark_as_generated(vars) when is_list(vars) do
+    Enum.map(vars, fn {name, meta, context} -> {name, [generated: true] ++ meta, context} end)
   end
 
+  defp mark_as_generated({name, meta, context}), do: {name, [generated: true] ++ meta, context}
+  defp mark_as_generated(other), do: other
+
   @doc false
   def __expand_pattern__({:when, meta, [left, right]}, caller) do
     left = expand_pattern(left, Macro.Env.to_match(caller))
@@ -952,7 +955,7 @@ defmodule ExUnit.Assertions do
   defp do_catch(kind, expr) do
     quote do
       try do
-        _ = unquote(expr)
+        _ = unquote(mark_as_generated(expr))
         flunk("Expected to catch #{unquote(kind)}, got nothing")
       rescue
         e in [ExUnit.AssertionError] ->