git and ref in configuration.cc

CMakeLists.txt

@@ -0,0 +1,60 @@
+cmake_minimum_required(VERSION 3.19)  # string(json
+cmake_policy(SET CMP0074 NEW)
+if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.24.0")
+    # Avoid warning about DOWNLOAD_EXTRACT_TIMESTAMP in CMake 3.24:
+    cmake_policy(SET CMP0135 NEW)
+endif()
+
+############################# Version and Metadata #############################
+
+# can't use PROJECT_SOURCE_DIR etc. before project() call
+list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules)
+include(DynamicVersion)
+dynamic_version(
+  PROJECT_PREFIX Libint2Compiler_
+  GIT_ARCHIVAL_FILE ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules/.git_archival.txt
+  OUTPUT_COMMIT LibintRepository_COMMIT
+  OUTPUT_VERSION LibintRepository_VERSION 
+  OUTPUT_DESCRIBE LibintRepository_DESCRIBE
+  OUTPUT_DISTANCE LibintRepository_DISTANCE
+  )
+
+project(
+  Libint2Compiler
+  VERSION ${LibintRepository_VERSION}
+  DESCRIPTION
+    "Libint: A library for the evaluation of molecular integrals of many-body operators over Gaussian functions"
+  HOMEPAGE_URL "http://libint.valeyev.net"
+  LANGUAGES CXX
+  )
+  # * http://libint.valeyev.net/ redirects to https://github.com/evaleev/libint
+
+set(${PROJECT_NAME}_AUTHORS "Edward F. Valeev")
+set(${PROJECT_NAME}_LICENSE "GPL-3.0 for generator; LGPL-3.0 for generated")
+
+# along with project(... VERSION) above scanned by dynamic_version() from `git
+#   describe`, these are the authoritative version source (formerly in configure.ac)
+set(LIBINT_BUILDID "post999")
+set(LIBINT_SOVERSION "2:3:0")
+
+include(int_versions)
+
+set(L2 Libint2)  # Namespace
+set(pnv libint2) # projectnameversion
+
+################################### Overview ###################################
+
+# CMake build overview:
+#
+#    >>> ls
+#    cmake/  COPYING  src/  tests/  ...
+#    >>> cmake -S. -Bbuild -GNinja -DCMAKE_INSTALL_PREFIX=/path/to/install-libint ...
+#    ...
+#    -- Generating done
+#    -- Build files have been written to: /current/dir/build
+#    >>> cmake --build build --target install
+
+################################## Main Project #################################
+
+# STRICTLY TEMPORARY FOR DEMONSTRATION PURPOSES
+configure_file(src/lib/libint/configuration.cc configuration.cc @ONLY)

cmake/modules/.git_archival.txt

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+node: $Format:%H$
+node-date: $Format:%cI$
+describe-name: $Format:%(describe:tags=true,match=?[0-9.]*)$
+ref-names: $Format:%D$