From cb507309937958c632147de87e8f1231d6698847 Mon Sep 17 00:00:00 2001
From: Antonio Sanchez <cantonios@google.com>
Date: Tue, 14 Sep 2021 10:57:22 -0700
Subject: [PATCH] Default eigen_packet_wrapper constructor.

This makes it trivial, allowing use of `memcpy`.

Fixes #2326

Upstream-Status: Backport [https://gitlab.com/libeigen/eigen/-/merge_requests/645/diffs?commit_id=cb507309937958c632147de87e8f1231d6698847]
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

* fixes build failures for arm targets with NEON enabled (e.g. -mfpu=neon-vfpv4)
  for recipes with -Werror enabled and gcc-11, e.g. fuse-core, robot-localization,
  prbt-ikfast-manipulator-plugin, rm-chassis-controllers in meta-ros1-noetic:

In file included from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/recipe-sysroot/usr/include/eigen3/Eigen/Core:214,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/macros.h:63,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/loss.h:37,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/constraint.h:37,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/src/constraint.cpp:34:
/jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/recipe-sysroot/usr/include/eigen3/Eigen/src/Core/arch/NEON/PacketMath.h: In function 'Packet Eigen::internal::pload(const typename Eigen::internal::unpacket_traits<T>::type*) [with Packet = Eigen::internal::eigen_packet_wrapper<int, 2>; typename Eigen::internal::unpacket_traits<T>::type = signed char]':
/jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/recipe-sysroot/usr/include/eigen3/Eigen/src/Core/arch/NEON/PacketMath.h:1671:9: error: 'void* memcpy(void*, const void*, size_t)' copying an object of non-trivial type 'Eigen::internal::Packet4c' {aka 'struct Eigen::internal::eigen_packet_wrapper<int, 2>'} from an array of 'const int8_t' {aka 'const signed char'} [-Werror=class-memaccess]
 1671 |   memcpy(&res, from, sizeof(Packet4c));
      |   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/recipe-sysroot/usr/include/eigen3/Eigen/Core:172,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/macros.h:63,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/loss.h:37,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/constraint.h:37,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/src/constraint.cpp:34:
/jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/recipe-sysroot/usr/include/eigen3/Eigen/src/Core/GenericPacketMath.h:159:8: note: 'Eigen::internal::Packet4c' {aka 'struct Eigen::internal::eigen_packet_wrapper<int, 2>'} declared here
  159 | struct eigen_packet_wrapper
      |        ^~~~~~~~~~~~~~~~~~~~
In file included from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/recipe-sysroot/usr/include/eigen3/Eigen/Core:214,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/macros.h:63,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/loss.h:37,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/constraint.h:37,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/src/constraint.cpp:34:
/jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/recipe-sysroot/usr/include/eigen3/Eigen/src/Core/arch/NEON/PacketMath.h: In function 'Packet Eigen::internal::ploadu(const typename Eigen::internal::unpacket_traits<T>::type*) [with Packet = Eigen::internal::eigen_packet_wrapper<int, 2>; typename Eigen::internal::unpacket_traits<T>::type = signed char]':
/jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/recipe-sysroot/usr/include/eigen3/Eigen/src/Core/arch/NEON/PacketMath.h:1716:9: error: 'void* memcpy(void*, const void*, size_t)' copying an object of non-trivial type 'Eigen::internal::Packet4c' {aka 'struct Eigen::internal::eigen_packet_wrapper<int, 2>'} from an array of 'const int8_t' {aka 'const signed char'} [-Werror=class-memaccess]
 1716 |   memcpy(&res, from, sizeof(Packet4c));
      |   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/recipe-sysroot/usr/include/eigen3/Eigen/Core:172,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/macros.h:63,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/loss.h:37,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/include/fuse_core/constraint.h:37,
                 from /jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/git/src/constraint.cpp:34:
/jenkins/mjansa/build/ros/webos-noetic-honister/tmp-glibc/work/raspberrypi4-webos-linux-gnueabi/fuse-core/0.4.2-1-r0/recipe-sysroot/usr/include/eigen3/Eigen/src/Core/GenericPacketMath.h:159:8: note: 'Eigen::internal::Packet4c' {aka 'struct Eigen::internal::eigen_packet_wrapper<int, 2>'} declared here
  159 | struct eigen_packet_wrapper
      |        ^~~~~~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors

---
 Eigen/src/Core/GenericPacketMath.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Eigen/src/Core/GenericPacketMath.h b/Eigen/src/Core/GenericPacketMath.h
index 8f8f64f15..72234288e 100644
--- a/Eigen/src/Core/GenericPacketMath.h
+++ b/Eigen/src/Core/GenericPacketMath.h
@@ -162,7 +162,7 @@ struct eigen_packet_wrapper
 {
   EIGEN_ALWAYS_INLINE operator T&() { return m_val; }
   EIGEN_ALWAYS_INLINE operator const T&() const { return m_val; }
-  EIGEN_ALWAYS_INLINE eigen_packet_wrapper() {}
+  EIGEN_ALWAYS_INLINE eigen_packet_wrapper() = default;
   EIGEN_ALWAYS_INLINE eigen_packet_wrapper(const T &v) : m_val(v) {}
   EIGEN_ALWAYS_INLINE eigen_packet_wrapper& operator=(const T &v) {
     m_val = v;
-- 
2.17.1