Andrew Burgess 14ea2c1b23 ld: Track changes to default region LMA even for empty sections
Given a linker script fragment like this:

   SECTIONS {
     . = 0x1000;
     .text   : AT(0x100) { *(.text)   }
     .data   : AT(0x200) { *(.data)   }
     .rodata : AT(0x300) { *(.rodata) }
   }

and an input file containing sections, '.text', '.data.1', and
'.rodata', then we'd expect the linker to place '.text' and '.rodata' in
the obvious way, and the '.data.1' orphan section would be located after
the '.data' section (assuming similar section properties).

Further, I believe that the expectation would be that the LMA for the
orphan '.data.1' section would start from 0x200 (as there is no '.data'
content).

However, right now, the LMA for '.data.1' would be 0x101, following on
from the '.text' section, this is because the change in LMA for the
'.data' section is not noticed by the linker, if there's no content in
the '.data' section.

What can be even more confusing to a user (though the cause is obvious
once you understand what's going on) is that adding some content to
'.data' will cause the orphan '.data.1' to switch to an LMA based off of
0x200.

This commit changes the behaviour so that an empty section that is in
the default lma region, and sets its lma, will adjust the lma of the
default region, this change will then be reflected in following sections
within the default lma memory region.

There's a new test to cover this issue that passes on a range of
targets, however, some targets generate additional sections, or have
stricter memory region size requirements that make it harder to come
up with a generic pass pattern, that still tests the required
features.  For now I've set the test to ignore these targets.

ld/ChangeLog:

	* ldlang.c (lang_size_sections_1): Shortcut loop only after
	tracking changes to the default regions LMA.
	* testsuite/ld-elf/orphan-9.ld: Extend header comment.
	* testsuite/ld-elf/orphan-10.d: New file.
	* testsuite/ld-elf/orphan-10.s: New file.
	* NEWS: Mention change in behaviour.
2017-03-09 21:11:06 +00:00
2017-01-05 00:02:57 +10:30
2017-01-05 00:03:07 +10:30
2015-08-31 12:53:36 +09:30
2014-11-16 13:43:48 +01:00
2015-07-27 07:49:05 -07:00
2016-12-31 11:47:16 +10:30
2014-11-16 13:43:48 +01:00
2014-11-16 13:43:48 +01:00
2016-01-12 08:44:52 -08:00
2014-02-06 11:01:57 +01:00
2014-11-16 13:43:48 +01:00
2014-11-16 13:43:48 +01:00
2014-11-16 13:43:48 +01:00

		   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.
Description
Unofficial mirror of sourceware binutils-gdb repository. Updated daily.
Readme 780 MiB
Languages
C 51.8%
Makefile 22.4%
Assembly 12.3%
C++ 6%
Roff 1.4%
Other 5.4%