/* Callgraph construction.
Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
Contributed by Jan Hubicka
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "tree-flow.h"
#include "langhooks.h"
#include "pointer-set.h"
#include "cgraph.h"
#include "intl.h"
#include "tree-gimple.h"
#include "tree-pass.h"
/* Walk tree and record all calls and references to functions/variables.
Called via walk_tree: TP is pointer to tree to be examined. */
static tree
record_reference (tree *tp, int *walk_subtrees, void *data)
{
tree t = *tp;
switch (TREE_CODE (t))
{
case VAR_DECL:
if (TREE_STATIC (t) || DECL_EXTERNAL (t))
{
varpool_mark_needed_node (varpool_node (t));
if (lang_hooks.callgraph.analyze_expr)
return lang_hooks.callgraph.analyze_expr (tp, walk_subtrees,
data);
}
break;
case FDESC_EXPR:
case ADDR_EXPR:
if (flag_unit_at_a_time)
{
/* Record dereferences to the functions. This makes the
functions reachable unconditionally. */
tree decl = TREE_OPERAND (*tp, 0);
if (TREE_CODE (decl) == FUNCTION_DECL)
cgraph_mark_needed_node (cgraph_node (decl));
}
break;
default:
/* Save some cycles by not walking types and declaration as we
won't find anything useful there anyway. */
if (IS_TYPE_OR_DECL_P (*tp))
{
*walk_subtrees = 0;
break;
}
if ((unsigned int) TREE_CODE (t) >= LAST_AND_UNUSED_TREE_CODE)
return lang_hooks.callgraph.analyze_expr (tp, walk_subtrees, data);
break;
}
return NULL_TREE;
}
/* Give initial reasons why inlining would fail on all calls from
NODE. Those get either nullified or usually overwritten by more precise
reason later. */
static void
initialize_inline_failed (struct cgraph_node *node)
{
struct cgraph_edge *e;
for (e = node->callers; e; e = e->next_caller)
{
gcc_assert (!e->callee->global.inlined_to);
gcc_assert (e->inline_failed);
if (node->local.redefined_extern_inline)
e->inline_failed = N_("redefined extern inline functions are not "
"considered for inlining");
else if (!node->local.inlinable)
e->inline_failed = N_("function not inlinable");
else
e->inline_failed = N_("function not considered for inlining");
}
}
/* Create cgraph edges for function calls.
Also look for functions and variables having addresses taken. */
static unsigned int
build_cgraph_edges (void)
{
basic_block bb;
struct cgraph_node *node = cgraph_node (current_function_decl);
struct pointer_set_t *visited_nodes = pointer_set_create ();
block_stmt_iterator bsi;
tree step;
/* Create the callgraph edges and record the nodes referenced by the function.
body. */
FOR_EACH_BB (bb)
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
{
tree stmt = bsi_stmt (bsi);
tree call = get_call_expr_in (stmt);
tree decl;
if (call && (decl = get_callee_fndecl (call)))
{
cgraph_create_edge (node, cgraph_node (decl), stmt,
bb->count,
bb->loop_depth);
walk_tree (&TREE_OPERAND (call, 1),
record_reference, node, visited_nodes);
if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
walk_tree (&GIMPLE_STMT_OPERAND (stmt, 0),
record_reference, node, visited_nodes);
}
else
walk_tree (bsi_stmt_ptr (bsi), record_reference, node, visited_nodes);
}
/* Look for initializers of constant variables and private statics. */
for (step = cfun->unexpanded_var_list;
step;
step = TREE_CHAIN (step))
{
tree decl = TREE_VALUE (step);
if (TREE_CODE (decl) == VAR_DECL
&& (TREE_STATIC (decl) && !DECL_EXTERNAL (decl))
&& flag_unit_at_a_time)
varpool_finalize_decl (decl);
else if (TREE_CODE (decl) == VAR_DECL && DECL_INITIAL (decl))
walk_tree (&DECL_INITIAL (decl), record_reference, node, visited_nodes);
}
pointer_set_destroy (visited_nodes);
initialize_inline_failed (node);
return 0;
}
struct tree_opt_pass pass_build_cgraph_edges =
{
NULL, /* name */
NULL, /* gate */
build_cgraph_edges, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
0, /* tv_id */
PROP_cfg, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
0, /* todo_flags_finish */
0 /* letter */
};
/* Record references to functions and other variables present in the
initial value of DECL, a variable. */
void
record_references_in_initializer (tree decl)
{
struct pointer_set_t *visited_nodes = pointer_set_create ();
walk_tree (&DECL_INITIAL (decl), record_reference, NULL, visited_nodes);
pointer_set_destroy (visited_nodes);
}
/* Rebuild cgraph edges for current function node. This needs to be run after
passes that don't update the cgraph. */
static unsigned int
rebuild_cgraph_edges (void)
{
basic_block bb;
struct cgraph_node *node = cgraph_node (current_function_decl);
block_stmt_iterator bsi;
cgraph_node_remove_callees (node);
node->count = ENTRY_BLOCK_PTR->count;
FOR_EACH_BB (bb)
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
{
tree stmt = bsi_stmt (bsi);
tree call = get_call_expr_in (stmt);
tree decl;
if (call && (decl = get_callee_fndecl (call)))
cgraph_create_edge (node, cgraph_node (decl), stmt,
bb->count,
bb->loop_depth);
}
initialize_inline_failed (node);
gcc_assert (!node->global.inlined_to);
return 0;
}
struct tree_opt_pass pass_rebuild_cgraph_edges =
{
NULL, /* name */
NULL, /* gate */
rebuild_cgraph_edges, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
0, /* tv_id */
PROP_cfg, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
0, /* todo_flags_finish */
0 /* letter */
};