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/* Callgraph construction.
Copyright (C) 2003-2020 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 3, 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 COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "tree.h"
#include "gimple.h"
#include "tree-pass.h"
#include "cgraph.h"
#include "gimple-fold.h"
#include "gimple-iterator.h"
#include "gimple-walk.h"
#include "ipa-utils.h"
#include "except.h"
/* Context of record_reference. */
struct record_reference_ctx
{
bool only_vars;
struct varpool_node *varpool_node;
};
/* Walk tree and record all calls and references to functions/variables.
Called via walk_tree: TP is pointer to tree to be examined.
When DATA is non-null, record references to callgraph.
*/
static tree
record_reference (tree *tp, int *walk_subtrees, void *data)
{
tree t = *tp;
tree decl;
record_reference_ctx *ctx = (record_reference_ctx *)data;
t = canonicalize_constructor_val (t, NULL);
if (!t)
t = *tp;
else if (t != *tp)
*tp = t;
switch (TREE_CODE (t))
{
case VAR_DECL:
case FUNCTION_DECL:
gcc_unreachable ();
break;
case FDESC_EXPR:
case ADDR_EXPR:
/* Record dereferences to the functions. This makes the
functions reachable unconditionally. */
decl = get_base_var (*tp);
if (TREE_CODE (decl) == FUNCTION_DECL)
{
cgraph_node *node = cgraph_node::get_create (decl);
if (!ctx->only_vars)
node->mark_address_taken ();
ctx->varpool_node->create_reference (node, IPA_REF_ADDR);
}
if (VAR_P (decl))
{
varpool_node *vnode = varpool_node::get_create (decl);
ctx->varpool_node->create_reference (vnode, IPA_REF_ADDR);
}
*walk_subtrees = 0;
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;
}
break;
}
return NULL_TREE;
}
/* Record references to typeinfos in the type list LIST. */
static void
record_type_list (cgraph_node *node, tree list)
{
for (; list; list = TREE_CHAIN (list))
{
tree type = TREE_VALUE (list);
if (TYPE_P (type))
type = lookup_type_for_runtime (type);
STRIP_NOPS (type);
if (TREE_CODE (type) == ADDR_EXPR)
{
type = TREE_OPERAND (type, 0);
if (VAR_P (type))
{
varpool_node *vnode = varpool_node::get_create (type);
node->create_reference (vnode, IPA_REF_ADDR);
}
}
}
}
/* Record all references we will introduce by producing EH tables
for NODE. */
static void
record_eh_tables (cgraph_node *node, function *fun)
{
eh_region i;
if (DECL_FUNCTION_PERSONALITY (node->decl))
{
tree per_decl = DECL_FUNCTION_PERSONALITY (node->decl);
cgraph_node *per_node = cgraph_node::get_create (per_decl);
node->create_reference (per_node, IPA_REF_ADDR);
per_node->mark_address_taken ();
}
i = fun->eh->region_tree;
if (!i)
return;
while (1)
{
switch (i->type)
{
case ERT_CLEANUP:
case ERT_MUST_NOT_THROW:
break;
case ERT_TRY:
{
eh_catch c;
for (c = i->u.eh_try.first_catch; c; c = c->next_catch)
record_type_list (node, c->type_list);
}
break;
case ERT_ALLOWED_EXCEPTIONS:
record_type_list (node, i->u.allowed.type_list);
break;
}
/* If there are sub-regions, process them. */
if (i->inner)
i = i->inner;
/* If there are peers, process them. */
else if (i->next_peer)
i = i->next_peer;
/* Otherwise, step back up the tree to the next peer. */
else
{
do
{
i = i->outer;
if (i == NULL)
return;
}
while (i->next_peer == NULL);
i = i->next_peer;
}
}
}
/* Computes the frequency of the call statement so that it can be stored in
cgraph_edge. BB is the basic block of the call statement. */
int
compute_call_stmt_bb_frequency (tree decl, basic_block bb)
{
return bb->count.to_cgraph_frequency
(ENTRY_BLOCK_PTR_FOR_FN (DECL_STRUCT_FUNCTION (decl))->count);
}
/* Mark address taken in STMT. */
static bool
mark_address (gimple *stmt, tree addr, tree, void *data)
{
addr = get_base_address (addr);
if (TREE_CODE (addr) == FUNCTION_DECL)
{
cgraph_node *node = cgraph_node::get_create (addr);
node->mark_address_taken ();
((symtab_node *)data)->create_reference (node, IPA_REF_ADDR, stmt);
}
else if (addr && VAR_P (addr)
&& (TREE_STATIC (addr) || DECL_EXTERNAL (addr)))
{
varpool_node *vnode = varpool_node::get_create (addr);
((symtab_node *)data)->create_reference (vnode, IPA_REF_ADDR, stmt);
}
return false;
}
/* Mark load of T. */
static bool
mark_load (gimple *stmt, tree t, tree, void *data)
{
t = get_base_address (t);
if (t && TREE_CODE (t) == FUNCTION_DECL)
{
/* ??? This can happen on platforms with descriptors when these are
directly manipulated in the code. Pretend that it's an address. */
cgraph_node *node = cgraph_node::get_create (t);
node->mark_address_taken ();
((symtab_node *)data)->create_reference (node, IPA_REF_ADDR, stmt);
}
else if (t && VAR_P (t) && (TREE_STATIC (t) || DECL_EXTERNAL (t)))
{
varpool_node *vnode = varpool_node::get_create (t);
((symtab_node *)data)->create_reference (vnode, IPA_REF_LOAD, stmt);
}
return false;
}
/* Mark store of T. */
static bool
mark_store (gimple *stmt, tree t, tree, void *data)
{
t = get_base_address (t);
if (t && VAR_P (t) && (TREE_STATIC (t) || DECL_EXTERNAL (t)))
{
varpool_node *vnode = varpool_node::get_create (t);
((symtab_node *)data)->create_reference (vnode, IPA_REF_STORE, stmt);
}
return false;
}
/* Record all references from cgraph_node that are taken in statement STMT. */
void
cgraph_node::record_stmt_references (gimple *stmt)
{
walk_stmt_load_store_addr_ops (stmt, this, mark_load, mark_store,
mark_address);
}
/* Create cgraph edges for function calls.
Also look for functions and variables having addresses taken. */
namespace {
const pass_data pass_data_build_cgraph_edges =
{
GIMPLE_PASS, /* type */
"*build_cgraph_edges", /* name */
OPTGROUP_NONE, /* optinfo_flags */
TV_NONE, /* tv_id */
PROP_cfg, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
0, /* todo_flags_finish */
};
class pass_build_cgraph_edges : public gimple_opt_pass
{
public:
pass_build_cgraph_edges (gcc::context *ctxt)
: gimple_opt_pass (pass_data_build_cgraph_edges, ctxt)
{}
/* opt_pass methods: */
virtual unsigned int execute (function *);
}; // class pass_build_cgraph_edges
unsigned int
pass_build_cgraph_edges::execute (function *fun)
{
basic_block bb;
cgraph_node *node = cgraph_node::get (current_function_decl);
gimple_stmt_iterator gsi;
tree decl;
unsigned ix;
/* Create the callgraph edges and record the nodes referenced by the function.
body. */
FOR_EACH_BB_FN (bb, fun)
{
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
gimple *stmt = gsi_stmt (gsi);
tree decl;
if (is_gimple_debug (stmt))
continue;
if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
{
decl = gimple_call_fndecl (call_stmt);
if (decl)
node->create_edge (cgraph_node::get_create (decl), call_stmt, bb->count);
else if (gimple_call_internal_p (call_stmt))
;
else
node->create_indirect_edge (call_stmt,
gimple_call_flags (call_stmt),
bb->count);
}
node->record_stmt_references (stmt);
if (gomp_parallel *omp_par_stmt = dyn_cast <gomp_parallel *> (stmt))
{
tree fn = gimple_omp_parallel_child_fn (omp_par_stmt);
node->create_reference (cgraph_node::get_create (fn),
IPA_REF_ADDR, stmt);
}
if (gimple_code (stmt) == GIMPLE_OMP_TASK)
{
tree fn = gimple_omp_task_child_fn (stmt);
if (fn)
node->create_reference (cgraph_node::get_create (fn),
IPA_REF_ADDR, stmt);
fn = gimple_omp_task_copy_fn (stmt);
if (fn)
node->create_reference (cgraph_node::get_create (fn),
IPA_REF_ADDR, stmt);
}
}
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
node->record_stmt_references (gsi_stmt (gsi));
}
/* Look for initializers of constant variables and private statics. */
FOR_EACH_LOCAL_DECL (fun, ix, decl)
if (VAR_P (decl)
&& (TREE_STATIC (decl) && !DECL_EXTERNAL (decl))
&& !DECL_HAS_VALUE_EXPR_P (decl)
&& TREE_TYPE (decl) != error_mark_node)
varpool_node::finalize_decl (decl);
record_eh_tables (node, fun);
return 0;
}
} // anon namespace
gimple_opt_pass *
make_pass_build_cgraph_edges (gcc::context *ctxt)
{
return new pass_build_cgraph_edges (ctxt);
}
/* Record references to functions and other variables present in the
initial value of DECL, a variable.
When ONLY_VARS is true, we mark needed only variables, not functions. */
void
record_references_in_initializer (tree decl, bool only_vars)
{
varpool_node *node = varpool_node::get_create (decl);
hash_set<tree> visited_nodes;
record_reference_ctx ctx = {false, NULL};
ctx.varpool_node = node;
ctx.only_vars = only_vars;
walk_tree (&DECL_INITIAL (decl), record_reference,
&ctx, &visited_nodes);
}
/* Rebuild cgraph edges for current function node. This needs to be run after
passes that don't update the cgraph. */
unsigned int
cgraph_edge::rebuild_edges (void)
{
basic_block bb;
cgraph_node *node = cgraph_node::get (current_function_decl);
gimple_stmt_iterator gsi;
node->remove_callees ();
node->remove_all_references ();
node->count = ENTRY_BLOCK_PTR_FOR_FN (cfun)->count;
FOR_EACH_BB_FN (bb, cfun)
{
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
gimple *stmt = gsi_stmt (gsi);
tree decl;
if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
{
decl = gimple_call_fndecl (call_stmt);
if (decl)
node->create_edge (cgraph_node::get_create (decl), call_stmt,
bb->count);
else if (gimple_call_internal_p (call_stmt))
;
else
node->create_indirect_edge (call_stmt,
gimple_call_flags (call_stmt),
bb->count);
}
node->record_stmt_references (stmt);
}
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
node->record_stmt_references (gsi_stmt (gsi));
}
record_eh_tables (node, cfun);
gcc_assert (!node->inlined_to);
return 0;
}
/* Rebuild cgraph references for current function node. This needs to be run
after passes that don't update the cgraph. */
void
cgraph_edge::rebuild_references (void)
{
basic_block bb;
cgraph_node *node = cgraph_node::get (current_function_decl);
gimple_stmt_iterator gsi;
ipa_ref *ref = NULL;
int i;
/* Keep speculative references for further cgraph edge expansion. */
for (i = 0; node->iterate_reference (i, ref);)
if (!ref->speculative)
ref->remove_reference ();
else
i++;
FOR_EACH_BB_FN (bb, cfun)
{
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
node->record_stmt_references (gsi_stmt (gsi));
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
node->record_stmt_references (gsi_stmt (gsi));
}
record_eh_tables (node, cfun);
}
namespace {
const pass_data pass_data_rebuild_cgraph_edges =
{
GIMPLE_PASS, /* type */
"*rebuild_cgraph_edges", /* name */
OPTGROUP_NONE, /* optinfo_flags */
TV_CGRAPH, /* tv_id */
PROP_cfg, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
0, /* todo_flags_finish */
};
class pass_rebuild_cgraph_edges : public gimple_opt_pass
{
public:
pass_rebuild_cgraph_edges (gcc::context *ctxt)
: gimple_opt_pass (pass_data_rebuild_cgraph_edges, ctxt)
{}
/* opt_pass methods: */
opt_pass * clone () { return new pass_rebuild_cgraph_edges (m_ctxt); }
virtual unsigned int execute (function *)
{
return cgraph_edge::rebuild_edges ();
}
}; // class pass_rebuild_cgraph_edges
} // anon namespace
gimple_opt_pass *
make_pass_rebuild_cgraph_edges (gcc::context *ctxt)
{
return new pass_rebuild_cgraph_edges (ctxt);
}
namespace {
const pass_data pass_data_remove_cgraph_callee_edges =
{
GIMPLE_PASS, /* type */
"*remove_cgraph_callee_edges", /* name */
OPTGROUP_NONE, /* optinfo_flags */
TV_NONE, /* tv_id */
0, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
0, /* todo_flags_finish */
};
class pass_remove_cgraph_callee_edges : public gimple_opt_pass
{
public:
pass_remove_cgraph_callee_edges (gcc::context *ctxt)
: gimple_opt_pass (pass_data_remove_cgraph_callee_edges, ctxt)
{}
/* opt_pass methods: */
opt_pass * clone () {
return new pass_remove_cgraph_callee_edges (m_ctxt);
}
virtual unsigned int execute (function *);
}; // class pass_remove_cgraph_callee_edges
unsigned int
pass_remove_cgraph_callee_edges::execute (function *)
{
cgraph_node *node = cgraph_node::get (current_function_decl);
node->remove_callees ();
node->remove_all_references ();
return 0;
}
} // anon namespace
gimple_opt_pass *
make_pass_remove_cgraph_callee_edges (gcc::context *ctxt)
{
return new pass_remove_cgraph_callee_edges (ctxt);
}