bump VG CMake kit to pull in ValeevGroup/kit-cmake@0341671 and try to…

… make install of Boost built from source work "correctly" ... when building Boost a main project to install BTAS when building Boost from source need to build `build-boost-in-BTAS` target before trying to install

README.md

@@ -9,19 +9,33 @@ Prerequisites
 * C++17 compiler
 * CMake
 * Boost C++ libraries
-  - Iterator
-  - (optional, but recommended) Container for fast small vectors
+  - (required) Container, Iterator, Random
   - (optional) Serialization for serialization (non-header-only)
 * (used by default, strongly recommended, but can be disabled) BLAS+LAPACK libraries and their BLAS++/LAPACK++ C++ APIs for optimized operations (non-header-only)
 
 Building and Installing
 =======================
 TL;DR version
-* cmake .
-* make check
+* `cmake -S /path/to/BTAS/srcdir -B /path/to/BTAS/builddir -DCMAKE_PREFIX_PATH="/path/to/boost;/path/to/blas/and/lapack"`
+* optional: `cmake --build /path/to/BTAS/builddir --target check`
+* if configured with `-DBTAS_BUILD_DEPS_FROM_SOURCE=ON`: `cmake --build /path/to/BTAS/builddir --target build-boost-in-BTAS`
+* `cmake --build /path/to/BTAS/builddir --target install`
+
+## obtaining prerequisites
+* Boost:
+  - It is recommended to use a package manager to install Boost. This can be doneas follows:
+    - APT package manager (e.g., on Ubuntu Linux): `apt-get install libboost-all-dev`
+    - Homebrew package manager (on MacOS) via `brew install boost`.
+  - You can also try to build Boost yourself by following instructions [here](https://www.boost.org/doc/libs/1_84_0/more/getting_started/unix-variants.html).
+  - Last resort is to let BTAS build Boost from source, as a CMake _subproject_ using [FetchContent](https://cmake.org/cmake/help/latest/module/FetchContent.html). Unfortunately, Boost's [emerging CMake harness](https://github.com/boostorg/cmake/) used to build it is not yet fully functional, hence may not be as robust as desired. Here are some ints:
+    - Configure with CMake cache variable `BTAS_BUILD_DEPS_FROM_SOURCE` to `ON` (either via command line or the `ccmake` GUI) 
+    - If BTAS is the top-level CMake project (i.e. it is not being built as a subproject itself) installing BTAS by building its install target may not build Boost libraries automatically. Thus the user may need to build `build-boost-in-BTAS` target manually before building `install` target.
 
 ## useful CMake variables
 - `CMAKE_CXX_COMPILER` -- specifies the C++ compiler (by default CMake will look for the C++ compiler in `PATH`)
+- `CMAKE_INSTALL_PREFIX` -- specifies the installation prefix (by default CMake will install to `/usr/local`)
+- `CMAKE_BUILD_TYPE` -- specifies the build type (by default CMake will build in `Release` mode)
+- `CMAKE_PREFIX_PATH` -- semicolon-separated list of paths specifying the locations of dependencies
 - `BTAS_USE_BLAS_LAPACK` -- specifies whether to enable the use of BLAS/LAPACK via the BLAS++/LAPACK++ APIs; the default is `ON`
 - `BTAS_BUILD_DEPS_FROM_SOURCE` -- specifies whether to enable building the missing dependencies (Boost) from source; the default is `OFF`
 - `BUILD_TESTING` -- specifies whether to build unit tests; the default is `ON`

external/boost.cmake

@@ -28,11 +28,14 @@ if (BTAS_BUILD_DEPS_FROM_SOURCE AND NOT DEFINED Boost_FETCH_IF_MISSING)
   set(Boost_FETCH_IF_MISSING 1)
 endif()
 include(${vg_cmake_kit_SOURCE_DIR}/modules/FindOrFetchBoost.cmake)
-if (DEFINED Boost_SOURCE_DIR)
+if (Boost_BUILT_FROM_SOURCE)
   set(BTAS_BUILT_BOOST_FROM_SOURCE 1)
 endif()
 
 # make BTAS depend on Boost
+if (NOT TARGET BTAS)
+  message(FATAL_ERROR "BTAS must be defined before including external/boost.cmake")
+endif()
 set(Boost_LIBRARIES Boost::headers;Boost::random)
 if (TARGET Boost::serialization)
   list(APPEND Boost_LIBRARIES Boost::serialization)
@@ -46,6 +49,26 @@ endif (TARGET Boost::serialization)
 target_link_libraries(BTAS INTERFACE ${Boost_LIBRARIES})
 target_compile_definitions(BTAS INTERFACE -DBTAS_HAS_BOOST_ITERATOR=1 -DBTAS_HAS_BOOST_CONTAINER=1 -DBTAS_DEFAULT_TARGET_MAX_INDEX_RANK=${TARGET_MAX_INDEX_RANK})
 
+# add artificial dependencies on some Boost components to ensure they are built before BTAS ... this is purely to
+# account for the fact that we do not properly deduce which targets we actually depend on AND some Boost targets
+# are not built when install target is built
+if (Boost_BUILT_FROM_SOURCE)
+  foreach (_target IN LISTS Boost_MODULAR_TARGETS_NOT_BUILT_BY_INSTALL)
+    add_dependencies(BTAS boost_${_target})
+  endforeach()
+  # unfortunately install ignores dependence of BTAS on these targets, presumably because it is an INTERFACE library
+  # and install target does not really build BTAS target ... this is OK if BTAS is built as a subproject and
+  # the BTAS target is consumed by the parent project, but if BTAS is built as a standalone project, then there is no
+  # correct way to install BTAS other than to ask the user to build a target that will build+install Boost first
+  if ("${PROJECT_NAME}" STREQUAL "${CMAKE_PROJECT_NAME}")
+    message(WARNING "BTAS is built as a standalone project, but Boost is built from source and cannot not be installed automatically.\nThus to install BTAS build the \"build-boost-in-BTAS\" target first, then build the \"install\" target")
+    add_custom_target(build-boost-in-BTAS)
+    foreach(_target IN LISTS Boost_FOUND_TARGETS Boost_MODULAR_TARGETS_NOT_BUILT_BY_INSTALL)
+      add_dependencies(build-boost-in-BTAS Boost::${_target})
+    endforeach()
+  endif()
+endif()
+
 # If building unit tests, perform a compile check with Boost
 # this is only possible, though, if did not build Boost from source,
 # since only imported targets can be used in CMAKE_REQUIRED_LIBRARIES

external/versions.cmake

@@ -1,4 +1,4 @@
-set(BTAS_TRACKED_VGCMAKEKIT_TAG 38f99f3da4810c97ed1d54f863120ae85120fa8f)
+set(BTAS_TRACKED_VGCMAKEKIT_TAG 034167146dc9ad28db07f5f726635693e1ec4a45)
 
 # likely can use earlier, but
 # - as of oct 2023 tested with 1.71 and up only