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/* Call stacks at program points.
Copyright (C) 2019-2020 Free Software Foundation, Inc.
Contributed by David Malcolm <dmalcolm@redhat.com>.
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 "pretty-print.h"
#include "tree.h"
#include "options.h"
#include "analyzer/call-string.h"
#include "ordered-hash-map.h"
#include "options.h"
#include "cgraph.h"
#include "function.h"
#include "cfg.h"
#include "basic-block.h"
#include "gimple.h"
#include "gimple-iterator.h"
#include "digraph.h"
#include "analyzer/supergraph.h"
#if ENABLE_ANALYZER
/* class call_string. */
/* call_string's copy ctor. */
call_string::call_string (const call_string &other)
: m_return_edges (other.m_return_edges.length ())
{
const return_superedge *e;
int i;
FOR_EACH_VEC_ELT (other.m_return_edges, i, e)
m_return_edges.quick_push (e);
}
/* call_string's assignment operator. */
call_string&
call_string::operator= (const call_string &other)
{
// would be much simpler if we could rely on vec<> assignment op
m_return_edges.truncate (0);
m_return_edges.reserve (other.m_return_edges.length (), true);
const return_superedge *e;
int i;
FOR_EACH_VEC_ELT (other.m_return_edges, i, e)
m_return_edges.quick_push (e);
return *this;
}
/* call_string's equality operator. */
bool
call_string::operator== (const call_string &other) const
{
if (m_return_edges.length () != other.m_return_edges.length ())
return false;
const return_superedge *e;
int i;
FOR_EACH_VEC_ELT (m_return_edges, i, e)
if (e != other.m_return_edges[i])
return false;
return true;
}
/* Print this to PP. */
void
call_string::print (pretty_printer *pp) const
{
pp_string (pp, "[");
const return_superedge *e;
int i;
FOR_EACH_VEC_ELT (m_return_edges, i, e)
{
if (i > 0)
pp_string (pp, ", ");
pp_printf (pp, "(SN: %i -> SN: %i in %s)",
e->m_src->m_index, e->m_dest->m_index,
function_name (e->m_dest->m_fun));
}
pp_string (pp, "]");
}
/* Generate a hash value for this call_string. */
hashval_t
call_string::hash () const
{
inchash::hash hstate;
int i;
const return_superedge *e;
FOR_EACH_VEC_ELT (m_return_edges, i, e)
hstate.add_ptr (e);
return hstate.end ();
}
/* Push the return superedge for CALL_SEDGE onto the end of this
call_string. */
void
call_string::push_call (const supergraph &sg,
const call_superedge *call_sedge)
{
gcc_assert (call_sedge);
const return_superedge *return_sedge = call_sedge->get_edge_for_return (sg);
gcc_assert (return_sedge);
m_return_edges.safe_push (return_sedge);
}
/* Count the number of times the top-most call site appears in the
stack. */
int
call_string::calc_recursion_depth () const
{
if (m_return_edges.is_empty ())
return 0;
const return_superedge *top_return_sedge
= m_return_edges[m_return_edges.length () - 1];
int result = 0;
const return_superedge *e;
int i;
FOR_EACH_VEC_ELT (m_return_edges, i, e)
if (e == top_return_sedge)
++result;
return result;
}
/* Comparator for call strings.
This implements a version of lexicographical order.
Return negative if A is before B.
Return positive if B is after A.
Return 0 if they are equal. */
int
call_string::cmp (const call_string &a,
const call_string &b)
{
unsigned len_a = a.length ();
unsigned len_b = b.length ();
unsigned i = 0;
while (1)
{
/* Consider index i; the strings have been equal up to it. */
/* Have both strings run out? */
if (i >= len_a && i >= len_b)
return 0;
/* Otherwise, has just one of the strings run out? */
if (i >= len_a)
return 1;
if (i >= len_b)
return -1;
/* Otherwise, compare the edges. */
const return_superedge *edge_a = a[i];
const return_superedge *edge_b = b[i];
int src_cmp = edge_a->m_src->m_index - edge_b->m_src->m_index;
if (src_cmp)
return src_cmp;
int dest_cmp = edge_a->m_dest->m_index - edge_b->m_dest->m_index;
if (dest_cmp)
return dest_cmp;
i++;
// TODO: test coverage for this
}
}
/* Assert that this object is sane. */
void
call_string::validate () const
{
/* Skip this in a release build. */
#if !CHECKING_P
return;
#endif
/* Each entry's "caller" should be the "callee" of the previous entry. */
const return_superedge *e;
int i;
FOR_EACH_VEC_ELT (m_return_edges, i, e)
if (i > 0)
gcc_assert (e->get_caller_function ()
== m_return_edges[i - 1]->get_callee_function ());
}
#endif /* #if ENABLE_ANALYZER */