Merge pull request #3827 from Rohde-Schwarz/feature/allow_disabling_c…

…make

Allow disabling installation of CMake configuration

configure.py

@@ -527,6 +527,11 @@ def process_command_line(args):
     build_group.add_option('--without-pkg-config', dest='with_pkg_config', action='store_false',
                            help=optparse.SUPPRESS_HELP)
 
+    build_group.add_option('--with-cmake-config', action='store_true', default=True,
+                           help=optparse.SUPPRESS_HELP)
+    build_group.add_option('--without-cmake-config', dest='with_cmake_config', action='store_false',
+                           help=optparse.SUPPRESS_HELP)
+
     docs_group = optparse.OptionGroup(parser, 'Documentation Options')
 
     docs_group.add_option('--with-documentation', action='store_true',
@@ -2299,6 +2304,9 @@ def test_exe_extra_ldflags():
 
     if options.with_pkg_config:
         variables['botan_pkgconfig'] = os.path.join(build_paths.build_dir, 'botan-%d.pc' % (Version.major()))
+    if options.with_cmake_config:
+        variables['botan_cmake_config'] = os.path.join(build_paths.build_dir, 'cmake', 'botan-config.cmake')
+        variables['botan_cmake_version_config'] = os.path.join(build_paths.build_dir, 'cmake', 'botan-config-version.cmake')
 
     # The name is always set because Windows build needs it
     variables['static_lib_name'] = '%s%s.%s' % (variables['lib_prefix'], variables['libname'],
@@ -3346,9 +3354,10 @@ def in_build_module_info(p):
     write_template(in_build_dir('build.h'), in_build_data('buildh.in'))
     write_template(in_build_dir('botan.doxy'), in_build_data('botan.doxy.in'))
 
-    robust_makedirs(in_build_dir("cmake"))
-    write_template(in_build_dir('cmake/botan-config.cmake'), in_build_data('botan-config.cmake.in'))
-    write_template(in_build_dir('cmake/botan-config-version.cmake'), in_build_data('botan-config-version.cmake.in'))
+    if options.with_cmake_config:
+        robust_makedirs(in_build_dir("cmake"))
+        write_template(in_build_dir('cmake/botan-config.cmake'), in_build_data('botan-config.cmake.in'))
+        write_template(in_build_dir('cmake/botan-config-version.cmake'), in_build_data('botan-config-version.cmake.in'))
 
     if 'botan_pkgconfig' in template_vars:
         write_template(template_vars['botan_pkgconfig'], in_build_data('botan.pc.in'))

doc/building.rst

@@ -540,6 +540,21 @@ is less of a problem - only the developer needs to worry about it. As
 long as they can remember where they installed Botan, they just have
 to set the appropriate flags in their Makefile/project file.
 
+CMake
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Starting in Botan 3.3.0 we provide a ``botan-config.cmake`` module to
+discover the installed library binaries and headers. This hooks into
+CMake's ``find_package()`` and comes with common features like version
+detection. Also, library consumers may specify which botan modules they
+require in ``find_package()``.
+
+Examples::
+
+   find_package(Botan 3.3.0)
+   find_package(Botan 3.3.0 COMPONENTS rsa ecdsa tls13)
+   find_package(Botan 3.3.0 OPTIONAL_COMPONENTS tls13_pqc)
+
 Language Wrappers
 ----------------------------------------
 

doc/packaging.rst

@@ -34,6 +34,19 @@ releases and packages.
 Any value set with ``--distribution-info`` flag will be included in the version
 string, and can read through the ``BOTAN_DISTRIBUTION_INFO`` macro.
 
+CMake Integration
+-----------------
+
+Starting in Botan 3.3.0, we ship ``botan-config.cmake`` files. While this config
+file is somewhat relocatable, it assumes the default installation directory
+structure as generated by ``make install``. If your distribution changes the
+directory layout of the installed files you might want to either adapt the final
+``botan-config.cmake`` file accordingly or leave it out entirely using
+``--without-cmake-config``.
+
+Please don't hesitate to give your feedback on this new feature by opening a
+ticket on the upstream GitHub.
+
 Minimize Distribution Patches
 ------------------------------
 

src/scripts/ci_check_install.py

@@ -134,7 +134,8 @@ def main(args=None):
     if not verify_library(build_config):
         return 1
 
-    if not verify_cmake_package(build_config):
+    has_cmake = 'botan_cmake_config' in build_config and 'botan_cmake_version_config' in build_config
+    if has_cmake and not verify_cmake_package(build_config):
         return 1
 
     return 0

src/scripts/install.py

@@ -210,12 +210,13 @@ def copy_executable(src, dst):
         copy_file(cfg['botan_pkgconfig'],
                   prepend_destdir(os.path.join(pkgconfig_dir, os.path.basename(cfg['botan_pkgconfig']))))
 
-    cmake_dir = os.path.join(prefix, lib_dir, cmake_dir, 'Botan-%s' % cfg["version"])
-    makedirs(prepend_destdir(cmake_dir))
-    copy_file('build/cmake/botan-config.cmake',
-                  prepend_destdir(os.path.join(cmake_dir, 'botan-config.cmake')))
-    copy_file('build/cmake/botan-config-version.cmake',
-                  prepend_destdir(os.path.join(cmake_dir, 'botan-config-version.cmake')))
+    if 'botan_cmake_config' in cfg and 'botan_cmake_version_config' in cfg:
+        cmake_dir = os.path.join(prefix, lib_dir, cmake_dir, 'Botan-%s' % cfg["version"])
+        makedirs(prepend_destdir(cmake_dir))
+        copy_file(cfg['botan_cmake_config'],
+                  prepend_destdir(os.path.join(cmake_dir, os.path.basename(cfg['botan_cmake_config']))))
+        copy_file(cfg['botan_cmake_version_config'],
+                  prepend_destdir(os.path.join(cmake_dir, os.path.basename(cfg['botan_cmake_version_config']))))
 
     if 'ffi' in cfg['mod_list'] and cfg['build_shared_lib'] is True and cfg['install_python_module'] is True:
         for ver in cfg['python_version'].split(','):