Some touchups to reflect that C++20 is now required for Axom

.github/workflows/ci-tests.yml

@@ -34,10 +34,10 @@ jobs:
       matrix:
         build_type: [ Debug, Release ]
         config:
-        - job_name: gcc@13.3.1, shared, benchmarks, c++20
+        - job_name: gcc@13.3.1, shared, benchmarks
           host_config: gcc@13.3.1.cmake
           compiler_image: ${{ needs.set_image_vars.outputs.gcc_docker_image }}
-          cmake_opts: '-DBUILD_SHARED_LIBS=ON -DBLT_CXX_STD=c++20 -DENABLE_BENCHMARKS:BOOL=ON'
+          cmake_opts: '-DBUILD_SHARED_LIBS=ON -DENABLE_BENCHMARKS:BOOL=ON'
           do_build: 'yes'
           do_benchmarks: 'yes'
         - job_name: gcc@13.3.1, shared, 32bit

RELEASE-NOTES.md

@@ -69,6 +69,8 @@ The Axom project release numbers follow [Semantic Versioning](http://semver.org/
 - Core: Deprecates the pointer-based interface to linear-, quadratic- and cubic- polynomial solvers in favor of an ArrayView-based interface
 
 ### Changed
+- Axom now requires `C++20` (or newer) and will default to that if not specified via `BLT_CXX_STD`.
+  Configuring with `BLT_CXX_STD` set to `c++17` or lower is now a configuration error.
 - Updates CMake code check targets to only use checked in files (via `git ls-files`, when available)
 - CMake: Simplified execution policy logic through use of `AXOM_EXECUTION_POLICIES` variable.
 - Core: Moved length unit parsing and conversion helpers into `axom::utilities`.

skills/building/SKILL.md

@@ -64,3 +64,44 @@ If the user does **not** specify a host-config file, determine the best match by
 ```
 
 Use its output as the `-hc` argument (as shown in the examples above). If the user explicitly provides a host-config file/path, use that instead.
+
+### Symlinked directories in the sandbox
+
+If configure/build commands report that an existing path is missing, inaccessible, or outside the sandbox, check whether the source, build, install, host-config, or TPL paths include symlinks. Compare logical and physical paths with:
+
+```bash
+pwd -P
+readlink -f <path>
+```
+
+Prefer physical paths resolved by `readlink -f` when invoking `config-build.py` (for `-bp`, `-ip`, `-hc`, and any explicit source/TPL paths), or restart the sandbox from the resolved workspace path. A symlinked path may appear outside the sandbox policy even when its resolved target is visible.
+
+### MPI and Slurm in the sandbox
+
+To run MPI-enabled commands from the sandbox, launch Codex with the `--mpi` command-line argument. This starts a Flux instance when needed. MPI through the sandbox is single-node only. If MPI or Slurm commands fail because no Flux allocation is available, stop and ask the user to restart the sandbox with `--mpi`.
+
+On Slurm-based systems, run Slurm commands through the Flux wrapper instead of the system executable, for example:
+
+```bash
+/usr/global/tools/flux_wrappers/bin/srun -n 2 <command>
+```
+
+Loading the flux wrappers before launching the agent allows you to run the srun wrapper, e.g.
+```bash
+module load flux_wrappers
+srun -n 2 <command>
+```
+
+When configuring builds whose MPI tests use `srun`, override CMake's MPI launcher:
+
+```bash
+./config-build.py -hc "$(./skills/building/scripts/determine_host_config)" -DMPIEXEC_EXECUTABLE=/usr/global/tools/flux_wrappers/bin/srun
+```
+
+### Shroud in the sandbox
+
+If CMake configuration has trouble with Shroud in the sandbox, unset the cached Shroud executable at configure time:
+
+```bash
+./config-build.py -hc "$(./skills/building/scripts/determine_host_config)" -USHROUD_EXECUTABLE
+```

src/CMakeLists.txt

@@ -108,8 +108,9 @@ if ("${PROJECT_SOURCE_DIR}" STREQUAL "${CMAKE_SOURCE_DIR}")
 endif()
 
 if("${BLT_CXX_STD}" STREQUAL "c++98" OR "${BLT_CXX_STD}" STREQUAL "c++11"
-                                     OR "${BLT_CXX_STD}" STREQUAL "c++14" )
-    message(FATAL_ERROR "Axom requires BLT_CXX_STD to be 'c++17' or above.")
+                                     OR "${BLT_CXX_STD}" STREQUAL "c++14"
+                                     OR "${BLT_CXX_STD}" STREQUAL "c++17" )
+    message(FATAL_ERROR "Axom requires BLT_CXX_STD to be 'c++20' or above.")
 endif()
 
 include(${BLT_SOURCE_DIR}/SetupBLT.cmake)

src/axom/config.hpp.in

@@ -107,6 +107,7 @@
 #cmakedefine AXOM_USE_LUMBERJACK
 #cmakedefine AXOM_USE_MINT
 #cmakedefine AXOM_USE_MIR
+#cmakedefine AXOM_USE_MULTIMAT
 #cmakedefine AXOM_USE_PRIMAL
 #cmakedefine AXOM_USE_QUEST
 #cmakedefine AXOM_USE_SIDRE

src/axom/core/utilities/About.cpp.in

@@ -99,6 +99,10 @@ void about(std::ostream &oss)
     comps.push_back("mir");
 #endif
 
+#ifdef AXOM_USE_MULTIMAT
+    comps.push_back("multimat");
+#endif
+
 #ifdef AXOM_USE_PRIMAL
     comps.push_back("primal");
 #endif

src/axom/quest/interface/python/setup.py.in

@@ -22,7 +22,7 @@ quest = Extension(
                   srcdir,
                   os.path.join(binarydir, 'include'),
                   os.path.join(mpidir, 'include')],
-    extra_compile_args=['-std=c++11'],   # gcc flag
+    extra_compile_args=['-std=c++@CMAKE_CXX_STANDARD@'],   # gcc flag
     libraries=['axom_quest'],
     library_dirs=[libdir],
     # rpath needed to find libquest.so during import

src/docs/sphinx/coding_guide/sec11_portability.rst

@@ -24,10 +24,10 @@ restricted.
 Portability
 --------------------------------------------------------------------
 
-Nothing beyond C++17
+Nothing beyond C++20
 ^^^^^^^^^^^^^^^^^^^^
 
-11.1 C++ language features beyond standard C++17 **must not** be used unless
+11.1 C++ language features beyond standard C++20 **must not** be used unless
 reviewed by the team and verified that the features are supported by all 
 compilers we need to support.
 

src/docs/sphinx/quickstart_guide/config_build.rst

@@ -26,8 +26,9 @@ Requirements, Dependencies, and Supported Compilers
 Basic requirements:
 ~~~~~~~~~~~~~~~~~~~
 
-  * C++ compiler with C++17 support at a minimum
-  * CMake with a minimum required version of 3.14 for CPU-only and CUDA builds,
+  * C++ compiler with C++20 support at a minimum
+  * CMake with a minimum required version of 3.14 for CPU-only builds,
+    a minimum version of 3.18 when building with CUDA support,
     and a minimum version of 3.21 when building with HIP support
   * Fortran Compiler (optional)
   * Python 3.8 at a minimum for python bindings (optional)
@@ -240,10 +241,11 @@ For more information, see `BLT host-config documentation <https://llnl-blt.readt
 C++20 and CUDA
 ~~~~~~~~~~~~~~~
 
-C++20 support in Axom is enabled by setting the ``BLT_CXX_STD`` variable in a
-host-config file to ``c++20``. If you get a configuration error indicating that
+Axom requires ``C++20``, and CUDA sources are compiled against the same standard.
+CMake first supported ``CUDA_STANDARD 20`` for an actual compiler in version 3.18,
+so CUDA-enabled builds require CMake 3.18 or newer. Axom's build system checks this
+and emits a fatal error otherwise. If you get a configuration error indicating that
 CUDA does not support C++20, the solution is to use a more recent CMake version.
-Consult CMake's release notes to find a version that supports C++20 and CUDA.
 
 Python helper script
 ~~~~~~~~~~~~~~~~~~~~
@@ -455,8 +457,8 @@ options to be provided, which are summarized in the following table.
 +------------------------------+------------------------------------------+
 
 .. note :: To configure the version of the C++ standard, you can supply one of the
-           following values for **BLT_CXX_STD**:  'c++17' or 'c++20'.
-           Axom requires at least 'c++17', the  default value.
+           following values for **BLT_CXX_STD**:  'c++20' or newer.
+           Axom requires at least 'c++20', the default value.
 
 
 Tools and features primarily intended for developers

src/examples/radiuss_tutorial/lesson_00/README.md

@@ -3,7 +3,7 @@
 In this lesson, we will develop a simple application that uses an installed version of Axom. 
 Specifically, we will print the version of Axom and some of its configuration properties.
 
-> :information_source: Our examples use the ``C++17`` standard since that's Axom's current version.
+> :information_source: Our examples use the ``C++20`` standard since that's Axom's current version.
 
 We will also be using the [fmt](https://fmt.dev/latest/index.html) library for string formatting, which Axom uses internally and vendors for its users.
 The vast majority of ``fmt`` has been included in recent C++ standards, starting with ``C++20``. See also the [fmt cheat sheet](https://hackingcpp.com/cpp/libs/fmt.html).
@@ -84,15 +84,15 @@ std::cout << axom::fmt::format("Version: {}", axom::getVersion()) << "\n\n";
 This includes the major, minor and patch version of Axom as well as the git SHA (when available).
 The above command might produce something like:
 ```
-Version: v0.9.0-f5b5b5d66
+Version: v0.14.0-b26e10df2
 ```
 
 The version is also available as compiler defines in ``axom/config.hpp``. The following corresponds to the above version:
 ```cpp
 #define AXOM_VERSION_MAJOR 0
-#define AXOM_VERSION_MINOR 9
+#define AXOM_VERSION_MINOR 14
 #define AXOM_VERSION_PATCH 0
-#define AXOM_VERSION_FULL  "v0.9.0"
+#define AXOM_VERSION_FULL  "v0.14.0"
 ```
 
 ## Checking details about the Axom configuration
@@ -114,18 +114,18 @@ We can run the application using:
 Its output should look something like:
 ```
 Axom information:
-  AXOM_VERSION_FULL: v0.9.0
+  AXOM_VERSION_FULL: v0.14.0
   AXOM_VERSION_MAJOR: 0
-  AXOM_VERSION_MINOR: 9
+  AXOM_VERSION_MINOR: 14
   AXOM_VERSION_PATCH: 0
-  AXOM_GIT_SHA: f5b5b5d66
+  AXOM_GIT_SHA: b26e10df2
 Compiler Settings: 
-  C++ Standard: c++17
-  Size of axom::IndexType: 4
+  C++ Standard: c++20
+  Size of axom::IndexType: 8
 Active programming models: { mpi;openmp }
-Available components: { core;inlet;klee;lumberjack;mint;primal;quest;sidre;slam;slic;spin }
+Available components: { core;bump;inlet;klee;lumberjack;mint;mir;multimat;primal;quest;sidre;sina;slam;slic;spin }
 Active built-in dependencies: { CLI11;fmt;sol;sparsehash }
-Active external dependencies: { adiak;caliper;conduit;hdf5;lua;mfem;raja;umpire }
+Active external dependencies: { adiak;caliper;conduit;hdf5;lua;mfem;opencascade;raja;scr;umpire }
 ```
 
 > :clapper: Run the example for this lesson

src/examples/shaping_tutorial/lesson_00/README.md

@@ -89,7 +89,7 @@ graph LR
 
 Let's get our feet wet with a first example that uses an installed version of Axom. Specifically, we will print the version of Axom and some of its configuration properties.
 
-> :information_source: Axom requires ``C++17`` or higher. This example uses the ``C++20`` standard.
+> :information_source: Axom requires ``C++20`` or higher. This example uses the ``C++20`` standard.
 
 > :memo: For details about configuring and installing Axom, see the [Zero-to-Axom Installation Guide](https://axom.readthedocs.io/en/develop/zero_to_axom/index.html)
 
@@ -167,15 +167,15 @@ std::cout << axom::fmt::format("Version: {}", axom::getVersion()) << "\n\n";
 This includes the major, minor and patch version of Axom as well as the git SHA (when available).
 The above command might produce something like:
 ```
-Version: v0.12.0-fd04d6d3d
+Version: v0.14.0-b26e10df2
 ```
 
 The version is also available as compiler defines in ``axom/config.hpp``. The following corresponds to the above version:
 ```cpp
 #define AXOM_VERSION_MAJOR 0
-#define AXOM_VERSION_MINOR 12
+#define AXOM_VERSION_MINOR 14
 #define AXOM_VERSION_PATCH 0
-#define AXOM_VERSION_FULL  "v0.12.0"
+#define AXOM_VERSION_FULL  "v0.14.0"
 ```
 
 ## Checking details about the Axom configuration
@@ -198,20 +198,18 @@ Its output should look something like:
 
 ```
 Axom information:
-  AXOM_VERSION_FULL: v0.12.0
+  AXOM_VERSION_FULL: v0.14.0
   AXOM_VERSION_MAJOR: 0
-  AXOM_VERSION_MINOR: 12
+  AXOM_VERSION_MINOR: 14
   AXOM_VERSION_PATCH: 0
-  AXOM_GIT_SHA: fd04d6d3d
+  AXOM_GIT_SHA: b26e10df2
 Compiler Settings: 
   C++ Standard: c++20
   Size of axom::IndexType: 8
-Active programming models:    { mpi;openmp }
-Available components:         { core;bump;inlet;klee;lumberjack;mint;mir;
-                                primal;quest;sidre;sina;slam;slic;spin }
+Active programming models: { mpi;openmp }
+Available components: { core;bump;inlet;klee;lumberjack;mint;mir;multimat;primal;quest;sidre;sina;slam;slic;spin }
 Active built-in dependencies: { CLI11;fmt;sol;sparsehash }
-Active external dependencies: { adiak;c2c;caliper;conduit;hdf5;lua;
-                                mfem;raja;scr;umpire }
+Active external dependencies: { adiak;c2c;caliper;conduit;hdf5;lua;mfem;opencascade;raja;scr;umpire }
 ```