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/* Rich optional information on why an optimization wasn't possible.
Copyright (C) 2018-2022 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 "backend.h"
#include "tree.h"
#include "gimple.h"
#include "pretty-print.h"
#include "opt-problem.h"
#include "dump-context.h"
#include "tree-pass.h"
#include "selftest.h"
/* opt_problem's ctor.
Use FMT and AP to emit a message to the "immediate" dump destinations
as if via:
dump_printf_loc (MSG_MISSED_OPTIMIZATION, loc, ...)
The optinfo_item instances are not emitted yet. Instead, they
are retained internally so that the message can be replayed and
emitted when this problem is handled, higher up the call stack. */
opt_problem::opt_problem (const dump_location_t &loc,
const char *fmt, va_list *ap)
: m_optinfo (loc, OPTINFO_KIND_FAILURE, current_pass)
{
/* We shouldn't be bothering to construct these objects if
dumping isn't enabled. */
gcc_assert (dump_enabled_p ());
/* Update the singleton. */
delete s_the_problem;
s_the_problem = this;
/* Print the location to the "immediate" dump destinations. */
dump_context &dc = dump_context::get ();
dc.dump_loc (MSG_MISSED_OPTIMIZATION, loc.get_user_location ());
/* Print the formatted string to this opt_problem's optinfo, dumping
the items to the "immediate" dump destinations, and storing items
for later retrieval. */
{
dump_pretty_printer pp (&dump_context::get (), MSG_MISSED_OPTIMIZATION);
text_info text;
text.err_no = errno;
text.args_ptr = ap;
text.format_spec = fmt; /* No i18n is performed. */
/* Phases 1 and 2, using pp_format. */
pp_format (&pp, &text);
/* Phase 3: dump the items to the "immediate" dump destinations,
and storing them into m_optinfo for later retrieval. */
pp.emit_items (&m_optinfo);
}
}
/* Emit this problem and delete it, clearing the current opt_problem. */
void
opt_problem::emit_and_clear ()
{
gcc_assert (this == s_the_problem);
m_optinfo.emit_for_opt_problem ();
delete this;
s_the_problem = NULL;
}
/* The singleton opt_problem *. */
opt_problem *opt_problem::s_the_problem;
#if CHECKING_P
namespace selftest {
static opt_result
function_that_succeeds ()
{
return opt_result::success ();
}
/* Verify that opt_result::success works. */
static void
test_opt_result_success ()
{
/* Run all tests twice, with and then without dumping enabled. */
for (int i = 0 ; i < 2; i++)
{
bool with_dumping = (i == 0);
temp_dump_context tmp (with_dumping, with_dumping,
MSG_ALL_KINDS | MSG_ALL_PRIORITIES);
if (with_dumping)
gcc_assert (dump_enabled_p ());
else
gcc_assert (!dump_enabled_p ());
opt_result res = function_that_succeeds ();
/* Verify that "success" can be used as a "true" boolean. */
ASSERT_TRUE (res);
/* Verify the underlying opt_wrapper<bool>. */
ASSERT_TRUE (res.get_result ());
ASSERT_EQ (res.get_problem (), NULL);
/* Nothing should have been dumped. */
ASSERT_DUMPED_TEXT_EQ (tmp, "");
optinfo *info = tmp.get_pending_optinfo ();
ASSERT_EQ (info, NULL);
}
}
/* Example of a function that fails, with a non-trivial
pre-canned error message. */
static opt_result
function_that_fails (const greturn *stmt)
{
gcc_assert (stmt);
gcc_assert (gimple_return_retval (stmt));
AUTO_DUMP_SCOPE ("function_that_fails", stmt);
return opt_result::failure_at (stmt,
"can't handle return type: %T for stmt: %G",
TREE_TYPE (gimple_return_retval (stmt)),
static_cast <const gimple *> (stmt));
}
/* Example of a function that indirectly fails. */
static opt_result
function_that_indirectly_fails (const greturn *stmt)
{
AUTO_DUMP_SCOPE ("function_that_indirectly_fails", stmt);
opt_result res = function_that_fails (stmt);
if (!res)
return res;
return opt_result::success ();
}
/* Verify that opt_result::failure_at works.
Simulate a failure handling a stmt at one location whilst considering
an optimization that's notionally at another location (as a microcosm
of e.g. a problematic statement within a loop that prevents loop
vectorization). */
static void
test_opt_result_failure_at (const line_table_case &case_)
{
/* Generate a location_t for testing. */
line_table_test ltt (case_);
const line_map_ordinary *ord_map
= linemap_check_ordinary (linemap_add (line_table, LC_ENTER, false,
"test.c", 0));
linemap_line_start (line_table, 5, 100);
/* A test location: "test.c:5:10". */
const location_t line_5 = linemap_position_for_column (line_table, 10);
/* Another test location: "test.c:6:12". */
const location_t line_6
= linemap_position_for_line_and_column (line_table, ord_map, 6, 12);
if (line_6 > LINE_MAP_MAX_LOCATION_WITH_COLS)
return;
/* Generate statements using "line_5" and "line_6" for testing. */
greturn *stmt_at_5 = gimple_build_return (integer_one_node);
gimple_set_location (stmt_at_5, line_5);
greturn *stmt_at_6 = gimple_build_return (integer_zero_node);
gimple_set_location (stmt_at_6, line_6);
/* Run with and then without dumping enabled. */
for (int i = 0; i < 2; i++)
{
bool with_dumping = (i == 0);
/* Run with all 4 combinations of
with and without MSG_PRIORITY_INTERNALS and
with and without MSG_PRIORITY_REEMITTED. */
for (int j = 0; j < 4; j++)
{
dump_flags_t filter = MSG_ALL_KINDS | MSG_PRIORITY_USER_FACING;
if (j / 2)
filter |= MSG_PRIORITY_INTERNALS;
if (j % 2)
filter |= MSG_PRIORITY_REEMITTED;
temp_dump_context tmp (with_dumping, with_dumping, filter);
if (with_dumping)
gcc_assert (dump_enabled_p ());
else
gcc_assert (!dump_enabled_p ());
/* Simulate attempting to optimize "stmt_at_6". */
opt_result res = function_that_indirectly_fails (stmt_at_6);
/* Verify that "failure" can be used as a "false" boolean. */
ASSERT_FALSE (res);
/* Verify the underlying opt_wrapper<bool>. */
ASSERT_FALSE (res.get_result ());
opt_problem *problem = res.get_problem ();
if (with_dumping)
{
ASSERT_NE (problem, NULL);
ASSERT_EQ (problem->get_dump_location ().get_location_t (),
line_6);
#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)
/* Verify that the problem captures the implementation location
it was emitted from. */
const dump_impl_location_t &impl_location
= problem->get_dump_location ().get_impl_location ();
ASSERT_STR_CONTAINS (impl_location.m_function,
"function_that_fails");
#endif
/* Verify that the underlying dump items are retained in the
opt_problem. */
const optinfo &info = problem->get_optinfo ();
ASSERT_EQ (info.get_dump_location ().get_location_t (), line_6);
ASSERT_EQ (info.num_items (), 4);
ASSERT_IS_TEXT (info.get_item (0), "can't handle return type: ");
ASSERT_IS_TREE (info.get_item (1), UNKNOWN_LOCATION, "int");
ASSERT_IS_TEXT (info.get_item (2), " for stmt: ");
ASSERT_IS_GIMPLE (info.get_item (3), line_6, "return 0;\n");
/* ...but not in the dump_context's pending_optinfo. */
ASSERT_EQ (tmp.get_pending_optinfo (), NULL);
/* Simulate emitting a high-level summary message, followed
by the problem. */
dump_printf_loc (MSG_MISSED_OPTIMIZATION, stmt_at_5,
"can't optimize loop\n");
problem->emit_and_clear ();
ASSERT_EQ (res.get_problem (), NULL);
/* Verify that the error message was dumped (when the failure
occurred). We can't use a switch here as not all of the
values are const expressions (using C++98). */
dump_flags_t effective_filter
= filter & (MSG_PRIORITY_INTERNALS | MSG_PRIORITY_REEMITTED);
if (effective_filter
== (MSG_PRIORITY_INTERNALS | MSG_PRIORITY_REEMITTED))
/* The -fopt-info-internals case. */
ASSERT_DUMPED_TEXT_EQ
(tmp,
"test.c:6:12: note: === function_that_indirectly_fails"
" ===\n"
"test.c:6:12: note: === function_that_fails ===\n"
"test.c:6:12: missed: can't handle return type: int"
" for stmt: return 0;\n"
"test.c:5:10: missed: can't optimize loop\n"
"test.c:6:12: missed: can't handle return type: int"
" for stmt: return 0;\n");
else if (effective_filter == MSG_PRIORITY_INTERNALS)
/* The default for dump files. */
ASSERT_DUMPED_TEXT_EQ
(tmp,
"test.c:6:12: note: === function_that_indirectly_fails"
" ===\n"
"test.c:6:12: note: === function_that_fails ===\n"
"test.c:6:12: missed: can't handle return type: int"
" for stmt: return 0;\n"
"test.c:5:10: missed: can't optimize loop\n");
else if (effective_filter == MSG_PRIORITY_REEMITTED)
/* The default when -fopt-info is enabled. */
ASSERT_DUMPED_TEXT_EQ
(tmp,
"test.c:5:10: missed: can't optimize loop\n"
"test.c:6:12: missed: can't handle return type: int"
" for stmt: return 0;\n");
else
{
gcc_assert (effective_filter == 0);
ASSERT_DUMPED_TEXT_EQ
(tmp,
"test.c:5:10: missed: can't optimize loop\n");
}
}
else
{
/* If dumping was disabled, then no problem should have been
created, and nothing should have been dumped. */
ASSERT_EQ (problem, NULL);
ASSERT_DUMPED_TEXT_EQ (tmp, "");
}
}
}
}
/* Run all of the selftests within this file. */
void
c_opt_problem_cc_tests ()
{
test_opt_result_success ();
for_each_line_table_case (test_opt_result_failure_at);
}
} // namespace selftest
#endif /* CHECKING_P */