build: use system MbedTLS when available

Since MbedTLS pre-3.0.0 doesn't ship neither a pkg-config file nor a CMake package config file it is required to use a custom FindMbedTLS.cmake file. Since yuzu requires CMAC support it is also needed to check for the `mbedtls_cipher_cmac` symbol. I also changed src/core/CMakeLists.txt to only link against mbedcrypto, as yuzu doesn't use the full MbedTLS library
2021-09-18 15:39:20 +02:00
parent 432d48d9c8
commit caa25146f2
4 changed files with 53 additions and 5 deletions
@@ -0,0 +1,43 @@
+# SPDX-FileCopyrightText: 2021 Andrea Pappacoda <andrea@pappacoda.it>
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# MbedTLS 3.0.0 will ship with a CMake package config file,
+# see ARMmbed/mbedtls@d259e347e6e3a630acfc1a811709ca05e5d3b92e,
+# so when yuzu will switch to that version this won't be required anymore.
+#
+# yuzu only uses mbedcrypto, searching for mbedtls and mbedx509 is not
+# needed.
+
+find_path(MbedTLS_INCLUDE_DIR mbedtls/cipher.h)
+
+find_library(MbedTLS_LIBRARY mbedcrypto)
+
+if (MbedTLS_INCLUDE_DIR AND MbedTLS_LIBRARY)
+    # Check for CMAC support
+    include(CheckSymbolExists)
+    set(CMAKE_REQUIRED_LIBRARIES ${MbedTLS_LIBRARY})
+    check_symbol_exists(mbedtls_cipher_cmac ${MbedTLS_INCLUDE_DIR}/mbedtls/cmac.h mbedcrypto_HAS_CMAC)
+    unset(CMAKE_REQUIRED_LIBRARIES)
+
+    # Check if version 2.x is available
+    file(READ "${MbedTLS_INCLUDE_DIR}/mbedtls/version.h" MbedTLS_VERSION_FILE)
+    string(REGEX MATCH "#define[ ]+MBEDTLS_VERSION_STRING[ ]+\"([0-9.]+)\"" _ ${MbedTLS_VERSION_FILE})
+    set(MbedTLS_VERSION "${CMAKE_MATCH_1}")
+
+    if (NOT TARGET MbedTLS::mbedcrypto)
+        add_library(MbedTLS::mbedcrypto UNKNOWN IMPORTED GLOBAL)
+        set_target_properties(MbedTLS::mbedcrypto PROPERTIES
+            IMPORTED_LOCATION "${MbedTLS_LIBRARY}"
+            INTERFACE_INCLUDE_DIRECTORIES "${MbedTLS_INCLUDE_DIR}"
+        )
+    endif()
+endif()
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(MbedTLS
+    REQUIRED_VARS
+        MbedTLS_LIBRARY
+        MbedTLS_INCLUDE_DIR
+        mbedcrypto_HAS_CMAC
+    VERSION_VAR MbedTLS_VERSION
+)