platform_bionic/tests/prio_ctor_test.cpp
Matthew Maurer de30635eb6 Put __*_ARRAY__ symbols before prioritized init/fini funcs
A constructor or destructor function with an integral priority is
placed in an .init_array or .fini_array section with the priority
suffixed to the section name:
 - __attribute__((constructor)) ==> .init_array
 - __attribute__((constructor(42))) ==> .init_array.42

The suffixed init/fini sections appear before the unsuffixed sections,
so the prioritized functions appeared before the __{INIT,FINI}_ARRAY__
symbols and were dropped when the symbols were used.

The (static) linker doesn't recognize priority suffixes on
.preinit_array.

This bug affected .init_array and .fini_array for static executables.
For dynamic executables, only .fini_array was affected, because
.init_array is handled by the dynamic loader instead, which uses
DT_INIT_ARRAY[SZ]. For DSOs, neither is affected, because the two
sections are only handled by the dynamic loader.

This patch also fixes a minor inconsistency where dynamic init/preinit
were passed argc/argv/envp, but static were not.

Bug: http://b/170983066
Test: bionic-unit-tests
Change-Id: I0fffa776e5d9bdb6f8af06b4c1af148236742fef
2020-11-02 17:28:41 -08:00

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1.1 KiB
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/*
* Copyright (C) 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <gtest/gtest.h>
#include <stdint.h>
static const char* record[4] = {};
static int idx = 0;
__attribute__((constructor(1000))) static void prio1000() {
record[idx++] = "prio1000";
}
__attribute__((constructor(1))) static void prio1() {
record[idx++] = "prio1";
}
__attribute__((constructor)) static void noprio() {
record[idx++] = "noprio";
}
TEST(prio_ctor, order) {
EXPECT_EQ(idx, 3);
EXPECT_STREQ(record[0], "prio1");
EXPECT_STREQ(record[1], "prio1000");
EXPECT_STREQ(record[2], "noprio");
}