calls.c (expand_call): Try to do a tail call for thunks at -O0 too.

	* calls.c (expand_call): Try to do a tail call for thunks at -O0 too.
	* cgraph.h (struct cgraph_thunk_info): Add indirect_offset.
	(cgraph_node::create_thunk): Add indirect_offset parameter.
	(thunk_adjust): Likewise.
	* cgraph.c (cgraph_node::create_thunk): Add indirect_offset parameter
	and initialize the corresponding field with it.
	(cgraph_node::dump): Dump indirect_offset field.
	* cgraphclones.c (duplicate_thunk_for_node): Deal with indirect_offset.
	* cgraphunit.c (cgraph_node::analyze): Be prepared for external thunks.
	(thunk_adjust): Add indirect_offset parameter and deal with it.
	(cgraph_node::expand_thunk): Deal with the indirect_offset field and
	pass it to thunk_adjust.  Do not call the target hook if it's non-zero
	or if the thunk is external or local.  Fix formatting.  Do not chain
	the RESULT_DECL to BLOCK_VARS.  Pass the static chain to the target,
	if any, in the GIMPLE representation.
	* ipa-icf.c (sem_function::equals_wpa): Deal with indirect_offset.
	* lto-cgraph.c (lto_output_node): Write indirect_offset field.
	(input_node): Read indirect_offset field.
	* tree-inline.c (expand_call_inline): Pass indirect_offset field in the
	call to thunk_adjust.
	* tree-nested.c (struct nesting_info): Add thunk_p field.
	(create_nesting_tree): Set it.
	(convert_all_function_calls): Copy static chain from targets to thunks.
	(finalize_nesting_tree_1): Return early for thunks.
	(unnest_nesting_tree_1): Do not finalize thunks.
	(gimplify_all_functions): Do not gimplify thunks.
cp/
	* method.c (use_thunk): Adjust call to cgraph_node::create_thunk.
ada/
	* gcc-interface/decl.c (is_cplusplus_method): Do not require C++
	convention on Interfaces.
	* gcc-interface/trans.c (Subprogram_Body_to_gnu): Try to create a
	bona-fide thunk and hand it over to the middle-end.
	(get_controlling_type): New function.
	(use_alias_for_thunk_p): Likewise.
	(thunk_labelno): New static variable.
	(make_covariant_thunk): New function.
	(maybe_make_gnu_thunk): Likewise.
	* gcc-interface/utils.c (finish_subprog_decl): Set DECL_CONTEXT of the
	result DECL here instead of...
	(end_subprog_body): ...here.

Co-Authored-By: Pierre-Marie de Rodat <derodat@adacore.com>

From-SVN: r264701

1 files changed, 29 insertions, 4 deletions

diff --git a/gcc/tree-nested.c b/gcc/tree-nested.c
index 4c8eda94f14..4579b4c5839 100644
--- a/gcc/tree-nested.c
+++ b/gcc/tree-nested.c
@@ -104,6 +104,7 @@ struct nesting_info
   tree chain_decl;
   tree nl_goto_field;
 
+  bool thunk_p;
   bool any_parm_remapped;
   bool any_tramp_created;
   bool any_descr_created;
@@ -834,6 +835,7 @@ create_nesting_tree (struct cgraph_node *cgn)
   info->mem_refs = new hash_set<tree *>;
   info->suppress_expansion = BITMAP_ALLOC (&nesting_info_bitmap_obstack);
   info->context = cgn->decl;
+  info->thunk_p = cgn->thunk.thunk_p;
 
   for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested)
     {
@@ -2786,6 +2788,8 @@ convert_all_function_calls (struct nesting_info *root)
      within the debugger.  */
   FOR_EACH_NEST_INFO (n, root)
     {
+      if (n->thunk_p)
+	continue;
       tree decl = n->context;
       if (!optimize)
 	{
@@ -2806,6 +2810,14 @@ convert_all_function_calls (struct nesting_info *root)
       chain_count += DECL_STATIC_CHAIN (decl);
     }
 
+  FOR_EACH_NEST_INFO (n, root)
+    if (n->thunk_p)
+      {
+	tree decl = n->context;
+	tree alias = cgraph_node::get (decl)->thunk.alias;
+	DECL_STATIC_CHAIN (decl) = DECL_STATIC_CHAIN (alias);
+      }
+
   /* Walk the functions and perform transformations.  Note that these
      transformations can induce new uses of the static chain, which in turn
      require re-examining all users of the decl.  */
@@ -2825,12 +2837,22 @@ convert_all_function_calls (struct nesting_info *root)
 
       FOR_EACH_NEST_INFO (n, root)
 	{
+	  if (n->thunk_p)
+	    continue;
 	  tree decl = n->context;
 	  walk_function (convert_tramp_reference_stmt,
 			 convert_tramp_reference_op, n);
 	  walk_function (convert_gimple_call, NULL, n);
 	  chain_count += DECL_STATIC_CHAIN (decl);
 	}
+
+      FOR_EACH_NEST_INFO (n, root)
+	if (n->thunk_p)
+	  {
+	    tree decl = n->context;
+	    tree alias = cgraph_node::get (decl)->thunk.alias;
+	    DECL_STATIC_CHAIN (decl) = DECL_STATIC_CHAIN (alias);
+	  }
     }
   while (chain_count != old_chain_count);
 
@@ -3055,12 +3077,13 @@ build_init_call_stmt (struct nesting_info *info, tree decl, tree field,
 static void
 finalize_nesting_tree_1 (struct nesting_info *root)
 {
-  gimple_seq stmt_list;
+  gimple_seq stmt_list = NULL;
   gimple *stmt;
   tree context = root->context;
   struct function *sf;
 
-  stmt_list = NULL;
+  if (root->thunk_p)
+    return;
 
   /* If we created a non-local frame type or decl, we need to lay them
      out at this time.  */
@@ -3340,7 +3363,8 @@ unnest_nesting_tree_1 (struct nesting_info *root)
   if (node->origin)
     {
        node->unnest ();
-       cgraph_node::finalize_function (root->context, true);
+       if (!root->thunk_p)
+	 cgraph_node::finalize_function (root->context, true);
     }
 }
 
@@ -3380,7 +3404,8 @@ gimplify_all_functions (struct cgraph_node *root)
   if (!gimple_body (root->decl))
     gimplify_function_tree (root->decl);
   for (iter = root->nested; iter; iter = iter->next_nested)
-    gimplify_all_functions (iter);
+    if (!iter->thunk.thunk_p)
+      gimplify_all_functions (iter);
 }
 
 /* Main entry point for this pass.  Process FNDECL and all of its nested