platform_bionic/libc/private/__dso_handle_so.c
Nick Kralevich 9d40326830 arm: rewrite crtbegin* as C files.
Rewrite
 crtbegin.S     -> crtbegin.c
 crtbegin_so.S  -> crtbegin_so.c

This change allows us to generate PIC code without relying
on text relocations.

As a consequence of this rewrite, also rewrite
  __dso_handle.S    -> __dso_handle.c
  __dso_handle_so.S -> __dso_handle_so.c
  atexit.S          -> atexit.c

In crtbegin.c _start, place the __PREINIT_ARRAY__, __INIT_ARRAY__,
__FINI_ARRAY__, and __CTOR_LIST__ variables onto the stack, instead of
passing a pointer to the text section of the binary.

This change appears sorta wonky, as I attempted to preserve,
as much as possible, the structure of the original assembly.
As a result, you have C files including other C files, and other
programming uglyness.

Result: This change reduces the number of files with text-relocations
from 315 to 19 on my Android build.

Before:
  $ scanelf -aR $OUT/system | grep TEXTREL | wc -l
  315

After:
  $ scanelf -aR $OUT/system | grep TEXTREL | wc -l
  19

Change-Id: Ib9f98107c0eeabcb606e1ddc7ed7fc4eba01c9c4
2012-06-01 14:41:27 -07:00

32 lines
1.5 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.
*/
__attribute__ ((visibility ("hidden")))
__attribute__ ((section (".data")))
void *__dso_handle;