=== Context ===
This patch is part of a patch series to add support for ARMv8-R
architecture. Its purpose is to add support for ARMv8-R in the linker.
=== Patch description ===
This patch is composed of 3 changes:
1) The main change is the addition of the logic for merging a file whose
Tag_CPU_arch build attribute is 15 (ARMv8-R). Namely, all pre-ARMv8 are
merged into ARMv8-R as well as ARMv8-R itself. ARMv8-A (14) merges into
ARMv8-A. ARMv8-M Baseline (16) and Mainline (17) are not allowed to
merge merge with ARMv8-R. Note that merging only occurs if the two
profiles are identical or one is S (Application or Realtime) and the
other is R.
2) using_thumb_only, using_thumb2_bl, using_thumb2 and arch_has_arm_nop
are updated according to capabilities of ARMv8-R and their BFD_ASSERT
updated to reflect that the logic is valid for ARMv8-R.
3) 2 build attribute merging tests are added to test the first change.
2017-06-24 Thomas Preud'homme <thomas.preudhomme@arm.com>
bfd/
* elf32-arm.c (using_thumb_only): Update list of architectures in
BFD_ASSERT for which the logic is valid.
(using_thumb2_bl): Likewise.
(using_thumb2): Likewise and return true for ARMv8-R.
(arch_has_arm_nop): Likewise.
(tag_cpu_arch_combine): New v8r table for ARMv8-R Tag_CPU_arch
merging logic. Update commentis for value 15 of v8m_baseline,
v8m_mainline and v4t_plus_v6_m arrays. Use v8r array to decide
merging of value 15 of Tag_CPU_arch.
ld/
* testsuite/ld-arm/arm-elf.exp (EABI attribute merging 11): New test.
(EABI attribute merging 12): Likewise.
* testsuite/ld-arm/attr-merge-11a.s: New file.
* testsuite/ld-arm/attr-merge-11b.s: New file.
* testsuite/ld-arm/attr-merge-11.attr: New file.
* testsuite/ld-arm/attr-merge-12a.s: New file.
* testsuite/ld-arm/attr-merge-12b.s: New file.
* testsuite/ld-arm/attr-merge-12.attr: New file.
This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
README for LD
This is the GNU linker. It is distributed with other "binary
utilities" which should be in ../binutils. See ../binutils/README for
more general notes, including where to send bug reports.
There are many features of the linker:
* The linker uses a Binary File Descriptor library (../bfd)
that it uses to read and write object files. This helps
insulate the linker itself from the format of object files.
* The linker supports a number of different object file
formats. It can even handle multiple formats at once:
Read two input formats and write a third.
* The linker can be configured for cross-linking.
* The linker supports a control language.
* There is a user manual (ld.texinfo), as well as the
beginnings of an internals manual (ldint.texinfo).
Installation
============
See ../binutils/README.
If you want to make a cross-linker, you may want to specify
a different search path of -lfoo libraries than the default.
You can do this by setting the LIB_PATH variable in ./Makefile
or using the --with-lib-path configure switch.
To build just the linker, make the target all-ld from the top level
directory (one directory above this one).
Porting to a new target
=======================
See the ldint.texinfo manual.
Reporting bugs etc
===========================
See ../binutils/README.
Known problems
==============
The Solaris linker normally exports all dynamic symbols from an
executable. The GNU linker does not do this by default. This is
because the GNU linker tries to present the same interface for all
similar targets (in this case, all native ELF targets). This does not
matter for normal programs, but it can make a difference for programs
which try to dlopen an executable, such as PERL or Tcl. You can make
the GNU linker export all dynamic symbols with the -E or
--export-dynamic command line option.
HP/UX 9.01 has a shell bug that causes the linker scripts to be
generated incorrectly. The symptom of this appears to be "fatal error
- scanner input buffer overflow" error messages. There are various
workarounds to this:
* Build and install bash, and build with "make SHELL=bash".
* Update to a version of HP/UX with a working shell (e.g., 9.05).
* Replace "(. ${srcdir}/scripttempl/${SCRIPT_NAME}.sc)" in
genscripts.sh with "sh ${srcdir}..." (no parens) and make sure the
emulparams script used exports any shell variables it sets.
Copyright (C) 2012-2017 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.
bff0500d7a