Move nested function info out of cgraph_node

this patch moves nested function information out of symbol table (to a summary).
This saves memory (especially at WPA time) and also makes nested function
support more contained.

gcc/ChangeLog:

2020-10-22  Jan Hubicka  <hubicka@ucw.cz>

	* cgraph.c: Include tree-nested.h
	(cgraph_node::create): Call maybe_record_nested_function.
	(cgraph_node::remove): Do not remove function from nested function
	infos.
	(cgraph_node::dump): Update.
	(cgraph_node::unnest): Move to tree-nested.c
	(cgraph_node::verify_node): Update.
	(cgraph_c_finalize): Call nested_function_info::release.
	* cgraph.h (struct symtab_node): Remove nested function info.
	* cgraphclones.c (cgraph_node::create_clone): Do not clone nested
	function info.
	* cgraphunit.c (cgraph_node::analyze): Update.
	(cgraph_node::expand): Do not worry about nested functions; they are
	lowered.
	(symbol_table::finalize_compilation_unit): Call
	nested_function_info::release.
	* gimplify.c: Include tree-nested.h
	(unshare_body): Update.
	(unvisit_body): Update.
	* omp-offload.c (omp_discover_implicit_declare_target): Update.
	* tree-nested.c: Include alloc-pool.h, tree-nested.h, symbol-summary.h
	(nested_function_sum): New static variable.
	(nested_function_info::get): New member function.
	(nested_function_info::get_create): New member function.
	(unnest_function): New function.
	(nested_function_info::~nested_function_info): New member function.
	(nested_function_info::release): New function.
	(maybe_record_nested_function): New function.
	(lookup_element_for_decl): Update.
	(check_for_nested_with_variably_modified): Update.
	(create_nesting_tree): Update.
	(unnest_nesting_tree_1): Update.
	(gimplify_all_functions): Update.
	(lower_nested_functions): Update.
	* tree-nested.h (class nested_function_info): New class.
	(maybe_record_nested_function): Declare.
	(unnest_function): Declare.
	(first_nested_function): New inline function.
	(next_nested_function): New inline function.
	(nested_function_origin): New inline function.

gcc/ada/ChangeLog:

2020-10-22  Jan Hubicka  <hubicka@ucw.cz>

	* gcc-interface/trans.c: Include tree-nested.h
	(walk_nesting_tree): Update for new nested function info.

gcc/c-family/ChangeLog:

2020-10-22  Jan Hubicka  <hubicka@ucw.cz>

	* c-gimplify.c: Include tree-nested.h
	(c_genericize): Update for new nested function info.

gcc/d/ChangeLog:

2020-10-22  Jan Hubicka  <hubicka@ucw.cz>

	* decl.cc: Include tree-nested.h
	(get_symbol_decl): Update for new nested function info.

1 files changed, 3 insertions, 1 deletions

diff --git a/gcc/ada/gcc-interface/trans.c b/gcc/ada/gcc-interface/trans.c
index f03d591..6babbd4 100644
--- a/gcc/ada/gcc-interface/trans.c
+++ b/gcc/ada/gcc-interface/trans.c
@@ -50,6 +50,7 @@
 #include "gomp-constants.h"
 #include "stringpool.h"
 #include "attribs.h"
+#include "tree-nested.h"
 
 #include "ada.h"
 #include "adadecode.h"
@@ -3696,7 +3697,8 @@ finalize_nrv_unc_r (tree *tp, int *walk_subtrees, void *data)
 static void
 walk_nesting_tree (struct cgraph_node *node, walk_tree_fn func, void *data)
 {
-  for (node = node->nested; node; node = node->next_nested)
+  for (node = first_nested_function (node);
+       node; node = next_nested_function (node))
     {
       walk_tree_without_duplicates (&DECL_SAVED_TREE (node->decl), func, data);
       walk_nesting_tree (node, func, data);