ceres-solver: update to v2.1.0-p0 with OpenBLAS support (#643)

Update `ceres-solver` to `v2.1.0-p0`.

Add option `WITH_OPENBLAS` (disabled in Hunter per default) to build
against `OpenBLAS` instead of generic `LAPACK`.

`OpenBLAS` `v0.3.21` provides a f2c-converted `LAPACK` `v3.9.0` copy,
which is used when building without a Fortran compiler.
This enables us to have a C++ only build, making static libraries
easier (no fortran runtime libs anymore).

Update dynLAPACK example with the new OpenBLAS settings (for SuiteSparse
as well).

* SuiteSparse: fix WITH_OPENBLAS setting, LAPACK doesn't have this flag

Author: NeroBurner

cmake/configs/default.cmake

@@ -219,7 +219,7 @@ hunter_default_version(catkin VERSION 0.7.17-p0)
 hunter_default_version(cctz VERSION 2.2.0)
 hunter_default_version(ccv VERSION 0.7-p6)
 hunter_default_version(cereal VERSION 1.2.2-p0)
-hunter_default_version(ceres-solver VERSION 2.0.0-p0)
+hunter_default_version(ceres-solver VERSION 2.1.0-p0)
 hunter_default_version(cgltf VERSION 1.10-f9a8804-p0)
 hunter_default_version(check_ci_tag VERSION 1.0.0)
 hunter_default_version(chromium_zlib VERSION 0.0.0-f87c2b10efb4-p0)

cmake/projects/ceres-solver/hunter.cmake

@@ -76,13 +76,26 @@ hunter_add_version(
     868f7b45b127d4eb2777ce889e0d273bd11f5f73
 )
 
+hunter_add_version(
+    PACKAGE_NAME
+    ceres-solver
+    VERSION
+    "2.1.0-p0"
+    URL
+    "https://github.com/cpp-pm/ceres-solver/archive/refs/tags/v2.1.0-p0.tar.gz"
+    SHA1
+    315d16137f08ed4b4ee303d505a6355f96b9a3aa
+)
+
 hunter_cmake_args(ceres-solver CMAKE_ARGS
     # explicitly remove dependency on gflags (only needed for tests)
     GFLAGS=OFF
     # explicitly disable suitesparse support
     LAPACK=OFF
     SUITESPARSE=OFF
     CXSPARSE=OFF # since 1.14.0-p0
+    # OpenBLAS flag, alternative to LAPACK since v2.1.0-p0
+    WITH_OPENBLAS=OFF
     # don't build tests
     BUILD_TESTING=OFF
     # also don't build examples: when suitesparse is enabled the examples need Fortran libraries

docs/packages/pkg/ceres-solver.rst

@@ -2,6 +2,8 @@
 
     ceres
     performant
+    OpenBLAS
+    Fortran
 
 .. index:: unsorted ; ceres-solver
 
@@ -85,3 +87,25 @@ add a local ``cmake/Hunter/config.cmake`` file with the following contents:
 
 With a dynamic ``LAPACK`` library the ``enable_language(Fortran)`` is not needed.
 But when shipping your project one must also ship the shared ``LAPACK`` library.
+
+with OpenBLAS as alternative to LAPACK
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Since ``v0.3.21`` ``OpenBLAS`` provides a f2c-converted copy of ``LAPACK`` ``v3.9.0``.
+This copy is used when building without a Fortran compiler.
+Using this in ``ceres-solver`` and ``SuiteSparse`` enables us to build a pure C++ library.
+Which means the resulting library can be static with no Fortran runtime dependencies.
+
+Since Hunter `v0.24.9 <https://github.com/cpp-pm/hunter/releases/tag/v0.24.9>`__
+``SuiteSparse`` per default is built against ``OpenBLAS``,
+which in Hunter per default compiles without Fortran and with ``LAPACK`` enabled.
+
+.. code-block:: cmake
+
+    hunter_config(ceres-solver
+      VERSION ${HUNTER_ceres-solver_VERSION} CMAKE_ARGS
+        LAPACK=ON
+        WITH_OPENBLAS=ON # since 2.1.0-p0
+        SUITESPARSE=ON
+        CXSPARSE=ON # since 1.14.0-p1
+    )

examples/SuiteSparse-dynLAPACK/config.cmake

@@ -1,7 +1,11 @@
+hunter_config(SuiteSparse
+  VERSION ${HUNTER_SuiteSparse_VERSION}
+  CMAKE_ARGS
+  BUILD_METIS=ON
+  WITH_OPENBLAS=OFF # we want to test generic LAPACK dynamic lib, not OpenBLAS
+)
 hunter_config(LAPACK
   VERSION ${HUNTER_LAPACK_VERSION}
   CMAKE_ARGS
   BUILD_SHARED_LIBS=ON
-  BUILD_METIS=ON
-  WITH_OPENBLAS=OFF # we want to test generic LAPACK dynamic lib, not OpenBLAS
 )

examples/ceres-solver-suitesparse-dynLAPACK/config.cmake

@@ -2,7 +2,14 @@ hunter_config(ceres-solver
   VERSION ${HUNTER_ceres-solver_VERSION} CMAKE_ARGS
     LAPACK=ON
     SUITESPARSE=ON
-    CXSPARSE=ON # since 1.14.0-p1
+    CXSPARSE=OFF # since 1.14.0-p1
+    WITH_OPENBLAS=OFF # we want to test generic LAPACK dynamic lib, not OpenBLAS
+)
+hunter_config(SuiteSparse
+  VERSION ${HUNTER_SuiteSparse_VERSION}
+  CMAKE_ARGS
+  BUILD_METIS=ON
+  WITH_OPENBLAS=OFF # we want to test generic LAPACK dynamic lib, not OpenBLAS
 )
 hunter_config(LAPACK
   VERSION ${HUNTER_LAPACK_VERSION}

examples/ceres-solver-suitesparse/config.cmake

@@ -3,4 +3,6 @@ hunter_config(ceres-solver
     LAPACK=ON
     SUITESPARSE=ON
     CXSPARSE=ON # since 1.14.0-p1
+    # sine 2.1.0, SuiteSparse 5.4.0 per default builds against OpenBLAS as well
+    WITH_OPENBLAS=ON
 )