platform_bionic/libc/arch-common/bionic/crtbegin.c
Elliott Hughes b348d5cda8 Build crtbegin with clang too.
If _start_main is static, clang optimizes it out and then generates an
undefined reference from the inline assembler, so let's explicitly tell
the compiler it's used.

Bug: N/A
Test: ran tests
Change-Id: Iba3d9c63abae9a0dc32f236b01783515f0190956
2017-07-25 11:54:33 -07:00

68 lines
2.6 KiB
C

/*
* Copyright (C) 2012 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "../../bionic/libc_init_common.h"
#include <stddef.h>
#include <stdint.h>
#define SECTION(name) __attribute__((__section__(name)))
SECTION(".preinit_array") void (*__PREINIT_ARRAY__)(void) = (void (*)(void)) -1;
SECTION(".init_array") void (*__INIT_ARRAY__)(void) = (void (*)(void)) -1;
SECTION(".fini_array") void (*__FINI_ARRAY__)(void) = (void (*)(void)) -1;
#undef SECTION
static void _start_main(void* raw_args) __used {
structors_array_t array;
array.preinit_array = &__PREINIT_ARRAY__;
array.init_array = &__INIT_ARRAY__;
array.fini_array = &__FINI_ARRAY__;
__libc_init(raw_args, NULL, &main, &array);
}
#define PRE ".text; .global _start; .type _start,%function; _start:"
#define POST "; .size _start, .-_start"
#if defined(__aarch64__)
__asm__(PRE "mov x0,sp; b _start_main" POST);
#elif defined(__arm__)
__asm__(PRE "mov r0,sp; b _start_main" POST);
#elif defined(__i386__)
__asm__(PRE "movl %esp,%eax; andl $~0xf,%esp; pushl %eax; calll _start_main" POST);
#elif defined(__x86_64__)
__asm__(PRE "movq %rsp,%rdi; andq $~0xf,%rsp; callq _start_main" POST);
#else
#error unsupported architecture
#endif
#undef PRE
#undef POST
#include "__dso_handle.h"
#include "atexit.h"
#include "pthread_atfork.h"