From: Iain Sandoe <iain@sandoe.co.uk>
Date: Thu, 11 Jun 2020 16:01:57 +0000 (+0100)
Subject: coroutines: Handle lambda closure pointers like 'this'.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=1c140cfbfa4b465a29ef26f1fdfef04c671e3c9c;p=gcc.git

coroutines: Handle lambda closure pointers like 'this'.

It was agreed amongst the implementors that the correct
interpretation of the standard is that lambda closure pointers
should be treated in the same manner as class object pointers.

gcc/cp/ChangeLog:

	* coroutines.cc (instantiate_coro_traits): Pass a reference
	to lambda closure objects to traits instantiation.
	(morph_fn_to_coro): Likewise for promise parameter
	preview and allocator lookup.
---

diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 3c8c70f5317..11fca9954ac 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -297,15 +297,14 @@ instantiate_coro_traits (tree fndecl, location_t kw)
 
   tree functyp = TREE_TYPE (fndecl);
   tree arg = DECL_ARGUMENTS (fndecl);
-  bool lambda_p = LAMBDA_FUNCTION_P (fndecl);
   tree arg_node = TYPE_ARG_TYPES (functyp);
   tree argtypes = make_tree_vec (list_length (arg_node)-1);
   unsigned p = 0;
 
   while (arg_node != NULL_TREE && !VOID_TYPE_P (TREE_VALUE (arg_node)))
     {
-      /* See PR94807, as to why we must exclude lambda here.  */
-      if (is_this_parameter (arg) && !lambda_p)
+      if (is_this_parameter (arg)
+	  || DECL_NAME (arg) == closure_identifier)
 	{
 	  /* We pass a reference to *this to the param preview.  */
 	  tree ct = TREE_TYPE (TREE_TYPE (arg));
@@ -3802,15 +3801,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
 	  parm.frame_type = actual_type;
 
 	  parm.this_ptr = is_this_parameter (arg);
-	  /* See PR94807.  When a lambda is in a template instantiation, the
-	     closure object is named 'this' instead of '__closure'.  */
-	  if (lambda_p)
-	    {
-	      parm.lambda_cobj = DECL_NAME (arg) == closure_identifier;
-	      gcc_checking_assert (!parm.this_ptr);
-	    }
-	  else
-	    parm.lambda_cobj = false;
+	  parm.lambda_cobj = lambda_p && DECL_NAME (arg) == closure_identifier;
 
 	  parm.trivial_dtor = TYPE_HAS_TRIVIAL_DESTRUCTOR (parm.frame_type);
 	  char *buf;
@@ -3960,9 +3951,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
 	{
 	  param_info *parm_i = param_uses->get (arg);
 	  gcc_checking_assert (parm_i);
-	  if (parm_i->lambda_cobj)
-	    vec_safe_push (args, arg);
-	  else if (parm_i->this_ptr)
+	  if (parm_i->this_ptr || parm_i->lambda_cobj)
 	    {
 	      /* We pass a reference to *this to the allocator lookup.  */
 	      tree tt = TREE_TYPE (TREE_TYPE (arg));
@@ -4166,9 +4155,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
 
 	  /* Add this to the promise CTOR arguments list, accounting for
 	     refs and special handling for method this ptr.  */
-	  if (parm.lambda_cobj)
-	    vec_safe_push (promise_args, arg);
-	  else if (parm.this_ptr)
+	  if (parm.this_ptr || parm.lambda_cobj)
 	    {
 	      /* We pass a reference to *this to the param preview.  */
 	      tree tt = TREE_TYPE (arg);