travis.yml: Test the release tarball

Add a job to generate the release tarball and build/install few
QEMU targets from it.

Ideally we should build the 'efi' target from the 'roms' directory,
but it is too time consuming.

This job is only triggered when a tag starting with 'v' is pushed,
which is the case with release candidate tags.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191007160450.3619-1-philmd@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

.travis.yml

@@ -343,3 +343,26 @@ matrix:
         - CONFIG="--target-list=xtensa-softmmu,arm-softmmu,aarch64-softmmu,alpha-softmmu"
         - TEST_CMD="make -j3 check-tcg V=1"
         - CACHE_NAME="${TRAVIS_BRANCH}-linux-gcc-default"
+
+
+    # Release builds
+    # The make-release script expect a QEMU version, so our tag must start with a 'v'.
+    # This is the case when release candidate tags are created.
+    - if: tag IS present AND tag =~ /^v\d+\.\d+(\.\d+)?(-\S*)?$/
+      env:
+        # We want to build from the release tarball
+        - BUILD_DIR="release/build/dir" SRC_DIR="../../.."
+        - BASE_CONFIG="--prefix=$PWD/dist"
+        - CONFIG="--target-list=x86_64-softmmu,aarch64-softmmu,armeb-linux-user,ppc-linux-user"
+        - TEST_CMD="make install -j3"
+        - QEMU_VERSION="${TRAVIS_TAG:1}"
+        - CACHE_NAME="${TRAVIS_BRANCH}-linux-gcc-default"
+      before_script:
+        - command -v ccache && ccache --zero-stats
+        - mkdir -p ${BUILD_DIR} && cd ${BUILD_DIR}
+      script:
+        - make -C ${SRC_DIR} qemu-${QEMU_VERSION}.tar.bz2
+        - ls -l ${SRC_DIR}/qemu-${QEMU_VERSION}.tar.bz2
+        - tar -xf ${SRC_DIR}/qemu-${QEMU_VERSION}.tar.bz2 && cd qemu-${QEMU_VERSION}
+        - ./configure ${BASE_CONFIG} ${CONFIG} || { cat config.log && exit 1; }
+        - make install