%global srcname dolfinx
%global upver 0.11.0.post0
%global sover 0.11

# DOLFINx compiles heavily templated C++; an LTO link of those objects is the
# peak memory consumer and can spike to several GB in a single process. Disable
# LTO so this builds on memory-constrained machines.
%global _lto_cflags %{nil}

# Cap parallelism by available memory (~4GB per job) instead of one job per
# core. %%limit_build emits the -jN flag, so it is substituted here rather than
# invoked as a standalone command.
%global _smp_mflags %{limit_build -m 4096}

# Fedora's MPI packaging conventions: build one flavour per MPI implementation
# into %%{_libdir}/<mpi>. Only openmpi is built here; add mpich by duplicating
# the build/install/files blocks with the %%{_mpich_*} macros.

Name:           fenics-dolfinx
Version:        0.11.0
Release:        %autorelease
Summary:        Next-generation FEniCS problem solving environment

License:        LGPL-3.0-or-later
URL:            https://github.com/FEniCS/dolfinx
Source:         %{url}/archive/v%{upver}/%{srcname}-%{upver}.tar.gz

BuildRequires:  cmake >= 3.21
BuildRequires:  gcc-c++
BuildRequires:  boost-devel >= 1.70
BuildRequires:  pugixml-devel
BuildRequires:  spdlog-devel
BuildRequires:  fenics-basix-devel >= 0.11.0
BuildRequires:  ufcx-devel >= 0.11.0
BuildRequires:  openmpi-devel
BuildRequires:  hdf5-openmpi-devel
BuildRequires:  petsc-openmpi-devel >= 3.15
BuildRequires:  ptscotch-openmpi-devel
# ptscotch-openmpi-devel's SCOTCHConfig.cmake unconditionally include()s
# scotchmetisTargets.cmake and ptscotchparmetisTargets.cmake, which are shipped
# only by the -parmetis subpackage with no dependency declared between them.
# Without this, find_package(SCOTCH) fails outright. (Fedora packaging bug.)
BuildRequires:  ptscotch-openmpi-devel-parmetis
BuildRequires:  superlu_dist-openmpi-devel
BuildRequires:  python3-devel
BuildRequires:  python3-nanobind >= 2.5.0
BuildRequires:  python3-scikit-build-core >= 0.11
# Python bindings are built in %%install against the staged C++ library, so the
# pyproject tooling is pulled in explicitly (no %%generate_buildrequires here).
BuildRequires:  python3-pip
BuildRequires:  python3-wheel
BuildRequires:  python3-mpi4py-openmpi
BuildRequires:  python3-petsc-openmpi
BuildRequires:  python3-fenics-basix >= 0.11.0
BuildRequires:  python3-fenics-ffcx >= 0.11.0
BuildRequires:  python3-fenics-ufl >= 2026.1.0
BuildRequires:  python3-numpy >= 2

%global _description %{expand:
DOLFINx is the computational environment of FEniCSx and implements the FEniCS
Problem Solving Environment in C++ and Python. It is the successor to the
legacy DOLFIN library, providing mesh handling, function spaces, assembly of
finite element forms and interfaces to PETSc linear algebra.

Note: SLEPc, ADIOS2 and KaHIP support are disabled because those libraries are
not currently packaged in Fedora.}

%description %_description

%package openmpi
Summary:        %{summary} (openmpi)
Requires:       openmpi

%description openmpi %_description

%package openmpi-devel
Summary:        Development files for DOLFINx (openmpi)
Requires:       %{name}-openmpi%{?_isa} = %{version}-%{release}
Requires:       fenics-basix-devel%{?_isa}
Requires:       ufcx-devel
Requires:       cmake-filesystem

%description openmpi-devel
Headers and CMake configuration for building C++ applications against the
openmpi build of DOLFINx.

%package -n python3-dolfinx-openmpi
Summary:        Python interface to DOLFINx (openmpi)
Requires:       %{name}-openmpi%{?_isa} = %{version}-%{release}
Requires:       python3-mpi4py-openmpi
# petsc4py, needed by dolfinx.fem.petsc
Requires:       python3-petsc-openmpi
Requires:       python3-fenics-basix >= 0.11.0
Requires:       python3-fenics-ffcx >= 0.11.0
Requires:       python3-fenics-ufl >= 2026.1.0

%description -n python3-dolfinx-openmpi
Python (nanobind) interface to DOLFINx, built against openmpi. Load the openmpi
environment module before use:

    module load mpi/openmpi-%{_arch}

%prep
%autosetup -n %{srcname}-%{upver}

# GCC 16's omp.h declares C++ templates (the OpenMP allocator helpers), so it can
# no longer be included inside an extern "C" block. superlu_dist.cpp wraps the
# SuperLU_DIST headers in one, and superlu_ddefs.h -> superlu_defs.h -> omp.h,
# so every template in omp.h lands with C linkage and the build stops:
#     /usr/lib/gcc/.../16/include/omp.h:455: error: template with C linkage
#     superlu_dist.cpp:10: note: 'extern "C"' linkage started here
# (11036717, f45-aarch64).
#
# gcc is NOT what distinguishes f45 here -- do not file this as an f45 gcc 16
# transition. f44 and f45 both ship gcc 16.2.1-2 with the same templated omp.h,
# and 10983216 built this very file on f44-aarch64 with it on 2026-09-14.
# The whole difference is one flag: the f45 compile line carries -fopenmp and
# the f44 one does not. superlu_defs.h guards its omp.h behind #ifdef _OPENMP
# -- identically in 8.2.0 (f44) and 9.2.1 (f45) -- so without -fopenmp omp.h
# never enters the extern "C" block at all. The superlu_dist version bump is a
# red herring; the .pc Cflags are the same and neither declares Requires:.
#
# The -fopenmp comes from PETSc, and the chain is:
#
#   1. Fedora builds petsc 3.25.5-3.fc45 --with-openmp. 3.24.6-4.fc44 is not.
#   2. So PETSc.pc differs:
#        f44  Cflags:  -I/usr/include/openmpi-<arch>/petsc
#        f45  Cflags:  -fopenmp -I/usr/include/openmpi-<arch>/petsc
#   3. dolfinx does pkg_search_module(PETSC ... IMPORTED_TARGET) and then
#      cpp/dolfinx/CMakeLists.txt:138  target_link_libraries(dolfinx PUBLIC
#      PkgConfig::PETSC) -- PUBLIC, so the Cflags land in
#      INTERFACE_COMPILE_OPTIONS and every single dolfinx TU gets -fopenmp.
#      (All 30 logged ninja steps on f45 carry it; zero on f44.)
#   4. _OPENMP is now defined, superlu_defs.h pulls omp.h, and it lands inside
#      the extern "C" -> templates with C linkage.
#
# CMake never prints "Found OpenMP" because no find_package(OpenMP) happens
# here -- which is exactly why grepping the configure output found nothing.
#
# Two consequences worth knowing:
#   * Not latent on f44. f44 builds clean today, and will keep doing so until
#     its petsc is rebuilt --with-openmp.
#   * NOT specific to this package. Anything on f45 that links PkgConfig::PETSC
#     now compiles with -fopenmp whether it asked for it or not. Any such
#     package that wraps a C library's headers in extern "C" will hit this same
#     omp.h error under gcc 16.
#
# Pull omp.h in first, with C++ linkage, so its include guard makes the nested
# include a no-op. Cheaper and less invasive than unwrapping the extern "C",
# which is there because the SuperLU_DIST headers genuinely are C.
sed -i '0,/^extern "C"$/s//#include <omp.h>\nextern "C"/' \
    cpp/dolfinx/la/superlu_dist.cpp
if ! grep -q '^#include <omp.h>$' cpp/dolfinx/la/superlu_dist.cpp; then
    echo "ERROR: omp.h pre-include not applied to superlu_dist.cpp" >&2
    exit 1
fi

# The extension module sets INSTALL_RPATH_USE_LINK_PATH as a *target property*,
# which overrides the -DCMAKE_INSTALL_RPATH_USE_LINK_PATH=OFF cache variable and
# appends the staged buildroot lib dir to its RPATH (check-buildroot then
# aborts). CMAKE_INSTALL_RPATH already records the correct final location, so
# drop the property.
sed -i '/INSTALL_RPATH_USE_LINK_PATH TRUE/d' python/CMakeLists.txt

# get_petsc_lib() locates libpetsc via petsc4py's petsc.cfg, but Fedora's
# petsc4py records PETSC_DIR as the RPM *build* directory
# (/builddir/build/BUILD/petsc-*/...), which exists nowhere at runtime -- so
# dolfinx.fem.petsc fails to import on any installed system. Add Fedora's real
# library as a candidate. Use the versioned runtime soname so this does not
# drag in petsc-openmpi-devel at runtime. Only one candidate can match, or
# upstream raises "More than one PETSc shared library found" -- the upstream
# paths never exist here, so exactly one does.
sed -i 's|^    candidate_paths = \[|    candidate_paths = [\n        "%{_libdir}/openmpi/lib/libpetsc.so.3",|' \
    python/dolfinx/fem/petsc.py

%build
%{_openmpi_load}
export CXXFLAGS="%{optflags}"
%cmake -S cpp \
    -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_INSTALL_PREFIX=%{_libdir}/openmpi \
    -DCMAKE_INSTALL_LIBDIR=lib \
    -DDOLFINX_ENABLE_SLEPC=OFF \
    -DDOLFINX_ENABLE_ADIOS2=OFF \
    -DDOLFINX_ENABLE_KAHIP=OFF \
    -DDOLFINX_ENABLE_PETSC=ON \
    -DDOLFINX_ENABLE_SCOTCH=ON \
    -DDOLFINX_ENABLE_SUPERLU_DIST=ON
%cmake_build
%{_openmpi_unload}

%install
%{_openmpi_load}
%cmake_install

# Python interface, linked against the staged C++ library
export CMAKE_PREFIX_PATH="%{buildroot}%{_libdir}/openmpi:${CMAKE_PREFIX_PATH}"
export LD_LIBRARY_PATH="%{buildroot}%{_libdir}/openmpi/lib:${LD_LIBRARY_PATH}"
# The MPI prefix is not on the default loader path, so the extension module
# does need an RPATH -- but it must record the *final* install location, not
# the buildroot it links against here (check-buildroot aborts otherwise).
export CMAKE_ARGS="-DDOLFINX_DIR=%{buildroot}%{_libdir}/openmpi/lib/cmake/dolfinx \
    -DCMAKE_INSTALL_RPATH=%{_libdir}/openmpi/lib \
    -DCMAKE_BUILD_WITH_INSTALL_RPATH=ON \
    -DCMAKE_INSTALL_RPATH_USE_LINK_PATH=OFF"
pushd python
%pyproject_wheel
%pyproject_install
popd

# Fedora MPI guidelines: MPI-flavoured Python modules must be namespaced per
# implementation (as mpi4py/petsc4py are), otherwise the openmpi and mpich
# builds would install the same paths and conflict.
mkdir -p %{buildroot}%{python3_sitearch}/openmpi
mv %{buildroot}%{python3_sitearch}/dolfinx \
   %{buildroot}%{python3_sitearch}/openmpi/
mv %{buildroot}%{python3_sitearch}/fenics_dolfinx-*.dist-info \
   %{buildroot}%{python3_sitearch}/openmpi/
%{_openmpi_unload}

%check
%{_openmpi_load}
# The extension's RPATH points at the final install location, which is not
# populated yet, so point the loader at the staged library for the import test.
export LD_LIBRARY_PATH="%{buildroot}%{_libdir}/openmpi/lib:${LD_LIBRARY_PATH}"
export PYTHONPATH="%{buildroot}%{python3_sitearch}/openmpi"
python3 -c "import dolfinx, dolfinx.fem, dolfinx.mesh, dolfinx.io; print('dolfinx', dolfinx.__version__)"
# Exercises the petsc.cfg workaround applied in %%prep: if the candidate path
# is wrong these raise RuntimeError, so this is a real regression test rather
# than a smoke check.
python3 -c "import dolfinx.fem.petsc; print('fem.petsc OK')"
python3 -c "import dolfinx.nls.petsc; print('nls.petsc OK')"
%{_openmpi_unload}

%files openmpi
%license COPYING COPYING.LESSER
%doc README.md ChangeLog.rst AUTHORS
%{_libdir}/openmpi/lib/libdolfinx.so.%{sover}*

# Headers stay under the MPI prefix so the exported CMake target's
# INTERFACE_INCLUDE_DIRECTORIES resolves to a path that actually exists.
%files openmpi-devel
%{_libdir}/openmpi/include/dolfinx/
%{_libdir}/openmpi/include/dolfinx.h
%{_libdir}/openmpi/lib/libdolfinx.so
%{_libdir}/openmpi/lib/cmake/dolfinx/
%{_libdir}/openmpi/lib/pkgconfig/dolfinx.pc
%{_libdir}/openmpi/lib/dolfinx/dolfinx.conf

%files -n python3-dolfinx-openmpi
%license COPYING COPYING.LESSER
%{python3_sitearch}/openmpi/dolfinx/
%{python3_sitearch}/openmpi/fenics_dolfinx-%{upver}.dist-info/

%changelog
%autochangelog