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/* Call stacks at program points.
Copyright (C) 2019-2022 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 "json.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
#if __GNUC__ >= 10
#pragma GCC diagnostic ignored "-Wformat-diag"
#endif
/* class call_string. */
/* struct call_string::element_t. */
/* call_string::element_t's equality operator. */
bool
call_string::element_t::operator== (const call_string::element_t &other) const
{
return (m_caller == other.m_caller && m_callee == other.m_callee);
}
/* call_string::element_t's inequality operator. */
bool
call_string::element_t::operator!= (const call_string::element_t &other) const
{
return !(*this == other);
}
function *
call_string::element_t::get_caller_function () const
{
return m_caller->get_function ();
}
function *
call_string::element_t::get_callee_function () const
{
return m_callee->get_function ();
}
/* call_string's copy ctor. */
call_string::call_string (const call_string &other)
: m_elements (other.m_elements.length ())
{
for (const call_string::element_t &e : other.m_elements)
m_elements.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_elements.truncate (0);
m_elements.reserve (other.m_elements.length (), true);
call_string::element_t *e;
int i;
FOR_EACH_VEC_ELT (other.m_elements, i, e)
m_elements.quick_push (*e);
return *this;
}
/* call_string's equality operator. */
bool
call_string::operator== (const call_string &other) const
{
if (m_elements.length () != other.m_elements.length ())
return false;
call_string::element_t *e;
int i;
FOR_EACH_VEC_ELT (m_elements, i, e)
if (*e != other.m_elements[i])
return false;
return true;
}
/* Print this to PP. */
void
call_string::print (pretty_printer *pp) const
{
pp_string (pp, "[");
call_string::element_t *e;
int i;
FOR_EACH_VEC_ELT (m_elements, i, e)
{
if (i > 0)
pp_string (pp, ", ");
pp_printf (pp, "(SN: %i -> SN: %i in %s)",
e->m_callee->m_index, e->m_caller->m_index,
function_name (e->m_caller->m_fun));
}
pp_string (pp, "]");
}
/* Return a new json::array of the form
[{"src_snode_idx" : int,
"dst_snode_idx" : int,
"funcname" : str},
...for each element in the callstring]. */
json::value *
call_string::to_json () const
{
json::array *arr = new json::array ();
for (const call_string::element_t &e : m_elements)
{
json::object *e_obj = new json::object ();
e_obj->set ("src_snode_idx",
new json::integer_number (e.m_callee->m_index));
e_obj->set ("dst_snode_idx",
new json::integer_number (e.m_caller->m_index));
e_obj->set ("funcname",
new json::string (function_name (e.m_caller->m_fun)));
arr->append (e_obj);
}
return arr;
}
/* Generate a hash value for this call_string. */
hashval_t
call_string::hash () const
{
inchash::hash hstate;
for (const call_string::element_t &e : m_elements)
hstate.add_ptr (e.m_caller);
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);
call_string::element_t e (return_sedge->m_dest, return_sedge->m_src);
m_elements.safe_push (e);
}
void
call_string::push_call (const supernode *caller,
const supernode *callee)
{
call_string::element_t e (caller, callee);
m_elements.safe_push (e);
}
call_string::element_t
call_string::pop ()
{
return m_elements.pop();
}
/* Count the number of times the top-most call site appears in the
stack. */
int
call_string::calc_recursion_depth () const
{
if (m_elements.is_empty ())
return 0;
const call_string::element_t top_return_sedge
= m_elements[m_elements.length () - 1];
int result = 0;
for (const call_string::element_t &e : m_elements)
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 node pairs. */
const call_string::element_t a_node_pair = a[i];
const call_string::element_t b_node_pair = b[i];
int src_cmp
= a_node_pair.m_callee->m_index - b_node_pair.m_callee->m_index;
if (src_cmp)
return src_cmp;
int dest_cmp
= a_node_pair.m_caller->m_index - b_node_pair.m_caller->m_index;
if (dest_cmp)
return dest_cmp;
i++;
// TODO: test coverage for this
}
}
/* Return the pointer to callee of the topmost call in the stack,
or NULL if stack is empty. */
const supernode *
call_string::get_callee_node () const
{
if(m_elements.is_empty ())
return NULL;
return m_elements[m_elements.length () - 1].m_callee;
}
/* Return the pointer to caller of the topmost call in the stack,
or NULL if stack is empty. */
const supernode *
call_string::get_caller_node () const
{
if(m_elements.is_empty ())
return NULL;
return m_elements[m_elements.length () - 1].m_caller;
}
/* 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. */
call_string::element_t *e;
int i;
FOR_EACH_VEC_ELT (m_elements, i, e)
if (i > 0)
{
gcc_assert (e->get_caller_function () ==
m_elements[i - 1].get_callee_function ());
}
}
#endif /* #if ENABLE_ANALYZER */