--- /dev/null
+# Copyright 1999-2020 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+CMAKE_ECLASS=cmake
+PYTHON_COMPAT=( python3_{6,7,8} )
+inherit cmake-multilib python-any-r1 toolchain-funcs
+
+DESCRIPTION="Nonlinear least-squares minimizer"
+HOMEPAGE="http://ceres-solver.org/"
+SRC_URI="http://ceres-solver.org/${P}.tar.gz"
+
+LICENSE="sparse? ( BSD ) !sparse? ( LGPL-2.1 ) cxsparse? ( BSD )"
+SLOT="0/1"
+KEYWORDS="~amd64 ~x86 ~amd64-linux ~x86-linux"
+IUSE="cxsparse c++11 doc examples gflags lapack openmp +schur sparse test"
+
+REQUIRED_USE="test? ( gflags ) sparse? ( lapack ) abi_x86_32? ( !sparse !lapack )"
+
+RESTRICT="!test? ( test )"
+
+BDEPEND="${PYTHON_DEPS}
+ >=dev-cpp/eigen-3.3.4:3
+ doc? (
+ dev-python/sphinx
+ dev-python/sphinx_rtd_theme
+ )
+ lapack? ( virtual/pkgconfig )
+"
+RDEPEND="
+ dev-cpp/glog[gflags?,${MULTILIB_USEDEP}]
+ cxsparse? ( sci-libs/cxsparse:0= )
+ lapack? ( virtual/lapack )
+ sparse? (
+ sci-libs/amd:0=
+ sci-libs/camd:0=
+ sci-libs/ccolamd:0=
+ sci-libs/cholmod:0=[metis]
+ sci-libs/colamd:0=
+ sci-libs/spqr:0=
+ )
+"
+DEPEND="${RDEPEND}"
+
+DOCS=( README.md VERSION )
+
+pkg_pretend() {
+ if [[ ${MERGE_TYPE} != binary ]] && use openmp; then
+ if [[ $(tc-getCXX) == *g++* ]] && ! tc-has-openmp; then
+ ewarn "OpenMP is not available in your current selected gcc"
+ die "need openmp capable gcc"
+ fi
+ fi
+}
+
+pkg_setup() {
+ use doc && python-any-r1_pkg_setup
+}
+
+src_prepare() {
+ cmake_src_prepare
+
+ # search paths work for prefix
+ sed -e "s:/usr:${EPREFIX}/usr:g" \
+ -i cmake/*.cmake || die
+
+ # remove Werror
+ sed -e 's/-Werror=(all|extra)//g' \
+ -i CMakeLists.txt || die
+}
+
+src_configure() {
+ # CUSTOM_BLAS=OFF EIGENSPARSE=OFF MINIGLOG=OFF CXX11=OFF
+ local mycmakeargs=(
+ -DBUILD_BENCHMARKS=OFF
+ -DBUILD_EXAMPLES=OFF
+ -DBUILD_TESTING=$(usex test)
+ -DCXX11=$(usex c++11)
+ -DBUILD_DOCUMENTATION=$(usex doc)
+ -DCERES_DOCS_INSTALL_DIR="${EPREFIX}"/usr/share/doc/${PF}
+ -DGFLAGS=$(usex gflags)
+ -DLAPACK=$(usex lapack)
+ -DOPENMP=$(usex openmp)
+ -DSCHUR_SPECIALIZATIONS=$(usex schur)
+ -DCXSPARSE=$(usex cxsparse)
+ -DSUITESPARSE=$(usex sparse)
+ )
+ use sparse || use cxsparse || mycmakeargs+=( -DEIGENSPARSE=ON )
+ cmake-multilib_src_configure
+}
+
+src_install() {
+ cmake-multilib_src_install
+
+ if use examples; then
+ docompress -x /usr/share/doc/${PF}/examples
+ dodoc -r examples data
+ fi
+}