[ANNOUNCE] Linaro Binary Toolchain Release-Candidate GCC 6.3-2017.05-rc1 - linaro-toolchain

4 May 2017


      The Linaro Binary Toolchain
============================
The Linaro GCC 6.3-2017.05-rc1 Release-Candidate is now available.
The GCC 6 Release series has significant changes from the GCC 5
release series.  For an explanation of the changes please see the
following website:
https://gcc.gnu.org/gcc-6/changes.html
For help in porting to GCC 6 please see the following explanation:
https://gcc.gnu.org/gcc-6/porting_to.html
Download release-candidate packages from:
(sources)
http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.05-rc1/
        (binaries)
http://snapshots.linaro.org/components/toolchain/binaries/6.3-2017.05-rc1/
Previous snapshots and release-candidates are at:
http://snapshots.linaro.org/components/toolchain/binaries/
Previous releases are at:
http://releases.linaro.org/components/toolchain/binaries/
A description of the arm and Aarch64 target triples can be found at:
https://collaborate.linaro.org/display/TCWGPUB/ARM+and+AArch64+Target+Triple...
Host Requirements
==================
Linaro officially supports the current and previous Ubuntu LTS
releases (as of the time of this release).  This does not mean that
the toolchain will not work on other/older Linux distributions.  See
the following for the life-time of Ubuntu LTS releases.
https://wiki.ubuntu.com/Releases
The host system upon which the cross-compiler will run requires a
minimum of glibc 2.14, because of API changes to glibc's memcpy API.
https://bugs.linaro.org/show_bug.cgi?id=1869
Package Versions
=================
Linaro GCC 6.3-2017.05-rc1
http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.05-rc1/
Linaro glibc 2.23 (linaro/2.23/master)
https://lists.gnu.org/archive/html/info-gnu/2016-02/msg00009.html
Linaro newlib 2.4-2016.03 (linaro_2.4-branch)
https://sourceware.org/ml/newlib/2016/msg00370.html
Linaro binutils 2.27 (linaro-local/linaro_binutils-2_27-branch)
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git%3Ba=blob_plain%3Bf=...
Linaro GDB 7.12 (gdb-7.12-branch)
https://lists.gnu.org/archive/html/info-gnu/2016-10/msg00007.html
Linaro toolchain package git branches are hosted at:
http://git.linaro.org/toolchain
NEWS for GCC 6 (as of Linaro GCC 6.3-2017.05-rc1)
==================================================
* Previous versions of the Linaro GCC 6 toolchain, when -static
  -E/—dynamic-list are passed to the linker, might create executables
  with dynamic sections which aren’t supported by run-time. This was
  exhibited in Perf Tools build system and has been fixed upstream and
  backported into Linaro Binutils 2.27 branch.
Linaro bugzilla #2926 : Perf tools compiled statically for AArch64
  with Linaro release 6.1 and later ones was not statically linked.
https://bugs.linaro.org/show_bug.cgi?id=2926
* The Linaro GCC 6.3-2017.03 snapshot fixed some ILP32 issues (TLS,
  exception handling, …) and these have been incorporated into this
  release.
* Previous versions of the Linaro GCC 6 toolchain were incorrectly
  generating floating-point code for soft-float Linux targets
  (arm-linux-gnueabi, and armeb-linux-gnueabi).  This escaped detection
  until recently because the soft-float targeted toolchains were
  configured to use general-purpose registers for passing floating-point
  values (which is what you would expect for soft-float toolchains) and
  the intra-routine floating-code was not noticed.
The issue would only show up on targets that were run on hardware that
  truly didn't have floating-point hardware where the kernel did not
  trap and emulate floating-point routines.  This has been solved in
  Linaro GCC 6.3-2017.02-rc2 by configuring the toolchain (using
  --with-float=soft) to generate code without any floating-point
  instructions at all (-mfloat-abi=soft).
https://review.linaro.org/#/c/16968/2
This change should not break compatibility between existing binaries
  compiled with these toolchains since the float-point parameter passing
  ABI is still the same.
* A bug/regression in the compiler has been identified whereby the
  target function that is invoked when calling a "weak" function
  directly is the "strong" override, whereas when calling the function
  via a pointer the "weak" implementation is used.  This would be
  noticed as inconsistent function invocation when invoking directly vs.
  invoking via function pointer.  This issue only affected 32-bit arm
  targets.  This regression has been fixed upstream and backported into
  Linaro GCC 6.3-2017.02-rc2.
GCC PR target/78253: [5/6/7 Regression] [ARM] call weak function
  instead of strong when called through pointer.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78253
Linaro bugzilla #2562: ARM GCC 5.2 call weak function instead of
  strong when called through pointer
https://bugs.linaro.org/show_bug.cgi?id=2562
* MS Windows does not support symlinks and the MS Windows archive
  extractor does not properly deep copy the symlink target
  files/directories into the symlinked directory structure when
  unpacking the toolchain archive.  This causes problems with missing
  dependencies when using the Linaro mingw toolchains, as identified in
  the following bugs:
https://bugs.linaro.org/show_bug.cgi?id=2684
      https://bugs.linaro.org/show_bug.cgi?id=2192
      https://bugs.linaro.org/show_bug.cgi?id=2762
This has been solved by copying files rather than using symlinks when
  the mingw targetted toolchain archives are created.
https://review.linaro.org/#/c/16415/
* Users of Linaro's toolchain have encountered problems when building
  projects with Autotools (specifically libtool):
https://bugs.linaro.org/show_bug.cgi?id=2764
The Linaro binary toolchain release contained files with a .la suffix
  as artifacts of the toolchain build process.  These .la files are
  helper files for libtool, but unlike a gcc install tree, they are not
  position independent and contain full paths.  Since these artifacts
  contain absolute paths they can actually mislead user invocation of
  libtool into not finding required libraries (because they reference
  the build tree, not the install location) and hence breaking Autotools
  builds.  These *.la file artifacts have been removed from Linaro
  toolchain binaries because they are unnecessary for users.
* The Linaro GCC 6.3-2017.01 snapshot added further enablement for
  ARMv8-M and these have been incorporated into this release.
* Compiling and statically linking some SPEC2006int tests against
  tcmalloc have been failing due to a problem with glibc's memory
  allocator function overrides.  This was fixed upstream:
https://sourceware.org/bugzilla/show_bug.cgi?id=20432
Backported into Linaro glibc 2.23:
commit 058b5a41d56b9a8860dede14d97dd443792d064b
  Author: Florian Weimer fweimer@redhat.com
  Date:   Fri Aug 26 22:40:27 2016 +0200
  malloc: Simplify static malloc interposition [BZ #20432]
* Host binaries for x86_64 linux hosts now have symbols and debug
  information stripped in order to reduce the size of the toolchain
  binary archives.  This reduces the archive size from 1.5G to 600M for
  aarch64-linux-gnu target with the gcc-6-branch.
* The GDB version was upgraded from GDB 7.11 in the Linaro GCC
  6.1-2016.08 release to GDB 7.12 in the Linaro GCC 6.2-2016.11 release.
* The Linaro GCC 6.2-2016.10 snapshot added AArch32 support for ARMv8.2
  and ARMv8m, as well as some AArch64 fixes for ARMv8.2, and bug fixes
  merged from FSF GCC 6.2.  This is available in the binary toolchain as
  of Linaro GCC 6.2-2016.11.
* Basic tuning support for the Qualcomm qdf24xx was added to the Linaro
  GCC 6.2-2016.10 snapshot and is available in the binary toolchain as
  of Linaro GCC 6.2-2016.11.
* IFUNC was disabled for baremetal targets, as it was causing test-suite
  failures, and is presently a Linux only feature.
* The gold linker was added to this binary release.
* Backported malloc_lock fix into Linaro newlib 2.4.
commit 2665915cfc46aa6403bb2efd473c523d3167e0cb
  Author: Andre Vieira (lists) Andre.SimoesDiasVieira@arm.com
  Date:   Thu Jun 16 12:23:51 2016 +0100
  Re-enable malloc_lock for newlib-nano
* Backported rawmemchr patch into Linaro newlib 2.4.
commit e7b1ee2ea6aa3ee1da41976407410e6202a098c5
  Author: Wilco Dijkstra Wilco.Dijkstra@arm.com
  Date:   Thu May 12 16:16:58 2016 +0000
  Add rawmemchr
* Backported strlen fix when using Thumb-2 and -Os -marm into Linaro
  newlib 2.4.
commit 5c02bcc086a96b174e1b9e1445a4a1770070107a
  Author: Thomas Preud'homme thomas.preudhomme@arm.com
  Date:   Wed May 11 17:18:48 2016 -0400
  Fix strlen using Thumb-2 with -Os -marm
* Backported fix for semihosting ARM when heapinfo not provided by
  debugger into Linaro newlib 2.4.
commit 5c9403eaf40951f8a4f55ed65f661b485ff44be7
  Author: David Hoover spm2@dangerous.li
  Date:   Thu Apr 21 07:12:24 2016 +0200
  Fixed semihosting for ARM when heapinfo not provided by debugger.
* Merged latest FSF glibc release/2.23/master into Linaro glibc 2.23.
* Backported __ASSUME_REQUEUE_PI check Linaro glibc 2.23 branch.
commit 2d20c3bf918cd94ebd4106693adb3a5c9272baba
  Author: Adhemerval Zanella adhemerval.zanella@linaro.org
  Date:   Tue May 17 10:16:39 2016 -0300
  Add runtime check for __ASSUME_REQUEUE_PI (BZ# 18463)
* Backported removal of __ASSUME_SET_ROBUST_LIST from Linaro glibc 2.23
  branch.
commit bb8f09d72756186a3d82a1f7b2adcf8bc1fbaed1
  Author: Adhemerval Zanella adhemerval.zanella@linaro.org
  Date:   Mon May 16 19:01:10 2016 -0300
  Remove __ASSUME_SET_ROBUST_LIST
* Backported removal of __ASSUME_FUTEX_LOCK_PI from Linaro glibc 2.23
  branch.
commit e48b4e7fed0de06dd7832ead48bea8ebc813a204
  Author: Adhemerval Zanella adhemerval.zanella@linaro.org
  Date:   Mon May 16 10:35:25 2016 -0300
  Remove __ASSUME_FUTEX_LOCK_PI
* Merged latest FSF binutils-2_27-branch into
  linaro_binutils-2_27-branch.
* The libwinpthread DLL is now copied into the host bin directory to
  satisfy mingw package dependencies.
* Backported GNU Linker fix.
commit fbc6c6763e70cb2376e2de990c7fc54c0ee44a59
  Author: Nick Clifton nickc@redhat.com
  Date:   Tue Aug 23 09:45:11 2016 +0100
  Fix seg-fault in ARM linker when trying to parse a binary file.
* Backported GNU Assembler fix for PR 20364
commit 5fe7ebe5ab43750abf8f490b785d99a1e598e7fd
  Author: Nick Clifton nickc@redhat.com
  Date:   Fri Aug 5 10:37:57 2016 +0100
  Fix the generation of alignment frags in code sections for AArch64.
https://sourceware.org/bugzilla/show_bug.cgi?id=20364
* Performance related backports from the following snapshots have been
  included: Linaro GCC 6.1-2016.06, Linaro GCC 6.1-2016.07, Linaro GCC
  6.1-2016.08, Linaro GCC 6.2-2016.09, Linaro GCC 6.2-2016.10, Linaro
  GCC 6.2-2016.11, Linaro GCC 6.2-2016.12, Linaro GCC 6.3-2017.01,
  Linaro GCC 6.3-2017.02, Linaro GCC 6.3-2017.03 and Linaro GCC
  6.3-2017.04.
See the following Linaro GCC snapshots:
http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.1-2016.06/
      http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.1-2016.07/
      http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.1-2016.08/
      http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.2-2016.09/
      http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.2-2016.10/
      http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.2-2016.11/
      http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.2-2016.12/
      http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.01/
      http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.02/
      http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.03/
      http://snapshots.linaro.org/components/toolchain/gcc-linaro/6.3-2017.04/
Contact Linaro
===============
File bugs at http://bugs.linaro.org
For Linaro member support see http://support.linaro.org
For Linaro community support email linaro-toolchain@lists.linaro.org