ci: Add 32-bit builds

.gitlab-ci.yml

@@ -10,7 +10,7 @@ variables:
 .monado.debian:buster:
   variables:
     FDO_DISTRIBUTION_VERSION: buster
-    FDO_DISTRIBUTION_TAG: "2019-04-28.0"
+    FDO_DISTRIBUTION_TAG: "2019-04-28.1"
 
 # Variables for build and usage of Debian 10 (Buster) + Android NDK image
 .monado.debian:buster-ndk:
@@ -50,7 +50,7 @@ stages:
     # Each most-derived job has a script to set up stuff for it.
     FDO_DISTRIBUTION_EXEC: "bash .gitlab-ci/${CI_JOB_NAME}.sh"
 
-# Debian Buster (x64)
+# Debian Buster (x64 + i386)
 debian:container_prep:
   stage: container_prep
   extends:
@@ -176,6 +176,24 @@ arch:meson:
   variables:
     MESON_ARGS: -Ddocs=disabled
 
+# Cross-compiling
+debian:meson:32bit:
+  extends:
+    - .monado.debian:buster # local
+    - .fdo.distribution-image@debian # from ci-templates
+    - .monado.build-meson # local
+  variables:
+    MESON_ARGS: --prefix /usr --libdir /usr/lib/i386-linux-gnu --cross-file ../.gitlab-ci/i386-cross.txt
+
+debian:cmake:32bit:
+  extends:
+    - .monado.debian:buster # local
+    - .fdo.distribution-image@debian # from ci-templates
+    - .monado.build-cmake # local
+  variables:
+    # OpenCV and local OpenHMD doesn't play nicely with us in multi-arch.
+    CMAKE_ARGS: -DCMAKE_TOOLCHAIN_FILE=../.gitlab-ci/i386.cmake -DBUILD_WITH_OPENCV=off -DBUILD_WITH_OPENHMD=off
+
 # Base of Android NDK builds.
 # Takes the last :-delimited part of the name as the ABI to build for,
 # so you don't need to do anything other than "extends" in the job

.gitlab-ci/debian:container_prep.sh

@@ -1,5 +1,9 @@
 #!/bin/bash
 
+(
+    cd $(dirname $0)
+    bash ./install-cross.sh
+)
 (
     cd $(dirname $0)
     bash ./build-openxr-openhmd.sh

.gitlab-ci/i386-cross.txt

@@ -0,0 +1,17 @@
+[binaries]
+c = '/usr/bin/i686-linux-gnu-gcc'
+cpp = '/usr/bin/i686-linux-gnu-g++'
+ar = '/usr/bin/i686-linux-gnu-ar'
+strip = '/usr/bin/i686-linux-gnu-strip'
+objcopy = '/usr/bin/i686-linux-gnu-objcopy'
+ld= '/usr/bin/i686-linux-gnu-ld'
+pkgconfig = '/usr/bin/i686-linux-gnu-pkg-config'
+
+[properties]
+needs_exe_wrapper = False
+
+[host_machine]
+system = 'linux'
+cpu_family = 'x86'
+cpu = 'i386'
+endian = 'little'

.gitlab-ci/i386.cmake

@@ -0,0 +1,37 @@
+# Toolchain file for 32-bit x86 linux build on 64-bit x86 linux
+# Developed for use with Debian and its derivatives
+#
+# Copyright 2019-2020 Collabora, Ltd.
+# SPDX-License-Identifier: BSL-1.0
+
+set(CMAKE_SYSTEM_NAME Linux)
+
+set(TARGET i686-linux-gnu)
+set(PREFIX ${TARGET}-)
+set(SUFFIX) # required for
+set(CMAKE_C_COMPILER ${PREFIX}gcc${SUFFIX})
+set(CMAKE_CXX_COMPILER ${PREFIX}g++${SUFFIX})
+
+set(CMAKE_C_COMPILER_AR ${PREFIX}gcc-ar${SUFFIX})
+set(CMAKE_CXX_COMPILER_AR ${PREFIX}gcc-ar${SUFFIX})
+set(CMAKE_C_COMPILER_RANLIB ${PREFIX}gcc-ranlib${SUFFIX})
+set(CMAKE_CXX_COMPILER_RANLIB ${PREFIX}gcc-ranlib${SUFFIX})
+set(CMAKE_NM ${PREFIX}gcc-nm${SUFFIX})
+set(CMAKE_OBJCOPY ${PREFIX}objcopy)
+set(CMAKE_OBJDUMP ${PREFIX}objdump)
+set(CMAKE_RANLIB ${PREFIX}ranlib)
+set(CMAKE_STRIP ${PREFIX}strip)
+
+set(PKG_CONFIG_EXECUTABLE ${PREFIX}pkg-config)
+
+if(NOT CMAKE_INSTALL_PREFIX)
+    set(CMAKE_INSTALL_PREFIX /usr/${TARGET})
+endif()
+
+set(CMAKE_SYSTEM_LIBRARY_PATH /usr/lib/i386-linux-gnu;/usr/lib32;/usr/${TARGET}/lib)
+
+set(CMAKE_FIND_ROOT_PATH /usr/${TARGET})
+
+# set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+# set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)

.gitlab-ci/install-cross.sh

@@ -0,0 +1,69 @@
+#!/bin/bash
+
+# Based on https://gitlab.freedesktop.org/mesa/mesa/-/blob/master/.gitlab-ci/container/x86_build.sh
+
+set -e
+set -o xtrace
+
+export DEBIAN_FRONTEND=noninteractive
+
+CROSS_ARCHITECTURES="i386"
+for arch in $CROSS_ARCHITECTURES; do
+    dpkg --add-architecture $arch
+done
+
+apt-get update
+
+for arch in $CROSS_ARCHITECTURES; do
+    # OpenCV and libuvc aren't on this list because
+    # they apparently can't be installed in both architectures at once
+    apt-get install -y --no-install-recommends --no-remove \
+            crossbuild-essential-${arch} \
+            libelf-dev:${arch} \
+            libavcodec-dev:${arch} \
+            libegl1-mesa-dev:${arch} \
+            libgl1-mesa-dev:${arch} \
+            libglvnd-dev:${arch} \
+            libhidapi-dev:${arch} \
+            libudev-dev:${arch} \
+            libusb-1.0-0-dev:${arch} \
+            libv4l-dev:${arch} \
+            libvulkan-dev:${arch} \
+            libwayland-dev:${arch} \
+            libx11-dev:${arch} \
+            libxcb-randr0-dev:${arch} \
+            libxrandr-dev:${arch} \
+            libxxf86vm-dev:${arch}
+
+    if [ "$arch" != "i386" ]; then
+        mkdir /var/cache/apt/archives/${arch}
+        apt-get install -y --no-remove \
+                libstdc++6:${arch}
+    fi
+done
+
+
+# for 64bit windows cross-builds
+# apt-get install -y --no-remove \
+#     libz-mingw-w64-dev \
+#     mingw-w64 \
+#     wine \
+#     wine32 \
+#     wine64
+
+
+apt-get autoremove -y --purge
+apt-get clean
+
+# Generate cross build files for Meson
+for arch in $CROSS_ARCHITECTURES; do
+  cross_file="/cross_file-$arch.txt"
+  /usr/share/meson/debcrossgen --arch "$arch" -o "$cross_file"
+  if [ "$arch" = "i386" ]; then
+    # Work around a bug in debcrossgen that should be fixed in the next release
+    sed -i "s|cpu_family = 'i686'|cpu_family = 'x86'|g" "$cross_file"
+  fi
+
+  # Rely on qemu-user being configured in binfmt_misc on the host
+  sed -i -e '/\[properties\]/a\' -e "needs_exe_wrapper = False" "$cross_file"
+done