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Senthil Kumar Selvaraj bf1865065f Fix PR ld/20545 - relaxation bugs in avr backend
Prior to the patch, addends for relocs were being adjusted even if
they went beyond an alignment boundary. This is wrong - to
preserve alignment constraints, the relaxation logic adds as many padding
bytes at the alignment boundary as was deleted, so addends beyond the
boundary should not be adjusted. avr-prop-7.s reproduces this
scenario.

Also, prior to this patch, the relaxation logic assumed that the addr
parameter pointed to the middle of the instruction to be deleted, and
that addr - count would therefore be the shrinked instruction's
address. This is true when actually shrinking instructions.

The alignment constraints handling logic also invokes the same logic
though, with addr as the starting offset of padding bytes and
with count as the number of bytes to be deleted. Calculating the
shrinked insn's address as addr - count is obviously wrong in this
case - that offset would point to count bytes before the last
non-padded byte. avr-prop-8.s reproduces this scenario.

To fix scenario 1, the patch adds an additional check to ensure reloc addends
aren't adjusted if they cross a shrink boundary. The shrink boundary
is either the section size or an alignment boundary. Addends pointing
at an alignment boundary don't need to be adjusted, as padding would
occur and keep the boundary the same. Addends pointing at section size
need to be adjusted though, as no padding occurs and the section size
itself would get decremented. The patch records whether padding
occured (did_pad) and uses that to detect and handle this condition.

To fix scenario 2, the patch adds an additional parameter
(delete_shrinks_insn) to elf32_avr_relax_delete_bytes to distinguish
instruction bytes deletion from padding bytes deletion. It then uses that to
correctly set shrinked_insn_address.

bfd/ChangeLog:

2016-09-02  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>

	PR ld/20545
	* elf32-avr.c (elf32_avr_relax_delete_bytes): Add parameter
	delete_shrinks_insn. Modify computation of shrinked_insn_address.
	Compute shrink_boundary and adjust addend only if
	addend_within_shrink_boundary.
	(elf32_avr_relax_section): Modify calls to
	elf32_avr_relax_delete_bytes to pass extra parameter.

ld/ChangeLog:

2016-09-02  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>

	PR ld/20545
	* testsuite/ld-avr/avr-prop-7.d: New test.
	* testsuite/ld-avr/avr-prop-7.s: New test.
	* testsuite/ld-avr/avr-prop-8.d: New test.
	* testsuite/ld-avr/avr-prop-8.s: New test.
2016-09-06 12:28:37 +05:30
bfd Fix PR ld/20545 - relaxation bugs in avr backend 2016-09-06 12:28:37 +05:30
binutils Check the external compression header size 2016-08-29 08:49:20 -07:00
config
cpu
elfcpp
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gas PowerPC VLE sh_flags and p_flags 2016-08-31 13:18:34 +09:30
gdb gdb/: Require a C++ compiler 2016-09-05 19:10:44 +01:00
gold Handle ARM-specific --target1-abs, --target1-rel and --target2 options 2016-09-02 15:51:59 -07:00
gprof Partially revert previous delta - move limit testing code to first scan over symbol file. 2016-08-30 13:51:43 +01:00
include Fixes to legacy ARC relocations. 2016-08-26 12:09:17 +02:00
intl
ld Fix PR ld/20545 - relaxation bugs in avr backend 2016-09-06 12:28:37 +05:30
libdecnumber
libiberty
opcodes Fixed issue with NULL pointer access on header var. 2016-08-30 18:21:13 +02:00
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		   README for GNU development tools

This directory contains various GNU compilers, assemblers, linkers, 
debuggers, etc., plus their support routines, definitions, and documentation.

If you are receiving this as part of a GDB release, see the file gdb/README.
If with a binutils release, see binutils/README;  if with a libg++ release,
see libg++/README, etc.  That'll give you info about this
package -- supported targets, how to use it, how to report bugs, etc.

It is now possible to automatically configure and build a variety of
tools with one command.  To build all of the tools contained herein,
run the ``configure'' script here, e.g.:

	./configure 
	make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
	make install

(If the configure script can't determine your type of computer, give it
the name as an argument, for instance ``./configure sun4''.  You can
use the script ``config.sub'' to test whether a name is recognized; if
it is, config.sub translates it to a triplet specifying CPU, vendor,
and OS.)

If you have more than one compiler on your system, it is often best to
explicitly set CC in the environment before running configure, and to
also set CC when running make.  For example (assuming sh/bash/ksh):

	CC=gcc ./configure
	make

A similar example using csh:

	setenv CC gcc
	./configure
	make

Much of the code and documentation enclosed is copyright by
the Free Software Foundation, Inc.  See the file COPYING or
COPYING.LIB in the various directories, for a description of the
GNU General Public License terms under which you can copy the files.

REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info
on where and how to report problems.