Finalize TF-PSA-Crypto.cmake to become the top cmake file

Signed-off-by: Ronald Cron <ronald.cron@arm.com>

tf-psa-crypto/TF-PSA-Crypto.cmake

@@ -1,4 +1,57 @@
+#
+# CMake build system design considerations:
+#
+# - Include directories:
+#   + Do not define include directories globally using the include_directories
+#     command but rather at the target level using the
+#     target_include_directories command. That way, it is easier to guarantee
+#     that targets are built using the proper list of include directories.
+#   + Use the PUBLIC and PRIVATE keywords to specify the scope of include
+#     directories. That way, a target linking to a library (using the
+#     target_link_libraries command) inherits from the library PUBLIC include
+#     directories and not from the PRIVATE ones.
+# - TF_PSA_CRYPTO_TARGET_PREFIX: CMake targets are designed to be alterable by
+#   calling CMake in order to avoid target name clashes, via the use of
+#   TF_PSA_CRYPTO_TARGET_PREFIX. The value of this variable is prefixed to the
+#   tfpsacrypto and tfpsacrypto-apidoc targets.
+#
+
+# We specify a minimum requirement of 3.10.2, but for now use 3.5.1 here
+# until our infrastructure catches up.
+cmake_minimum_required(VERSION 3.5.1)
+
 include(CMakePackageConfigHelpers)
+
+# Include convenience functions for printing properties and variables, like
+# cmake_print_properties(), cmake_print_variables().
+include(CMakePrintHelpers)
+
+# https://cmake.org/cmake/help/latest/policy/CMP0011.html
+# Setting this policy is required in CMake >= 3.18.0, otherwise a warning is generated. The OLD
+# policy setting is deprecated, and will be removed in future versions.
+cmake_policy(SET CMP0011 NEW)
+# https://cmake.org/cmake/help/latest/policy/CMP0012.html
+# Setting the CMP0012 policy to NEW is required for FindPython3 to work with CMake 3.18.2
+# (there is a bug in this particular version), otherwise, setting the CMP0012 policy is required
+# for CMake versions >= 3.18.3 otherwise a deprecated warning is generated. The OLD policy setting
+# is deprecated and will be removed in future versions.
+cmake_policy(SET CMP0012 NEW)
+
+set(TF_PSA_CRYPTO_VERSION 0.1.0)
+set(TF_PSA_CRYPTO_SOVERSION 0)
+
+if(TEST_CPP)
+    project("TF-PSA-Crypto"
+        LANGUAGES C CXX
+        VERSION ${TF_PSA_CRYPTO_VERSION}
+    )
+else()
+    project("TF-PSA-Crypto"
+        LANGUAGES C
+        VERSION ${TF_PSA_CRYPTO_VERSION}
+    )
+endif()
+
 include(GNUInstallDirs)
 
 # Determine if TF-PSA-Crypto is being built as a subproject using add_subdirectory()