From 47db072e9ec749c6be7c0a27d64d7fbd75748d60 Mon Sep 17 00:00:00 2001
From: Gyorgy Szing <Gyorgy.Szing@arm.com>
Date: Wed, 8 Dec 2021 04:20:34 +0100
Subject: [PATCH] Enhance mbedtls fetch process

Update management of MbedTLS external component to be optimized
for download speed insted of availability.
The updated process is:
  - check if binary is available. If yes configure build to use it
    and stop.
  - if not, check is source is available. If yes, build it and use
    the resulting binary.
  - if not, then download the source using git, compile it and use
    the resulting binary

The following variables can be set on the command line to alter the
behavior of the module:
  - MBEDTLS_URL git repo URL to fetch from.
  - MBEDTLS_REFSPEC revision to fetch
  - MBEDTLS_SOURCE_DIR to specify location of source code in
    local file syetem.
  - MBEDTLS_INSTALL_DIR to specify location of binary.

I.e. cmake -S <...> -B <...> -DMBEDTLS_INSTALL_DIR=~/mbedtls
will make the resulting binary installed to ~/mbedtls. This can be
used later to speed up a clean build an use the prebuilt binary.

Change-Id: I8a9ad8b3303e6dfa0a7c9c3d7e4b4787b94d925a
Signed-off-by: Gyorgy Szing <Gyorgy.Szing@arm.com>

Upstream-Status: Pending [Not submitted to upstream yet]
Signed-off-by: Emekcan Aras <Emekcan.Aras@arm.com>


---
 external/MbedTLS/MbedTLS.cmake | 192 ++++++++++++++++++++-------------
 1 file changed, 119 insertions(+), 73 deletions(-)

diff --git a/external/MbedTLS/MbedTLS.cmake b/external/MbedTLS/MbedTLS.cmake
index 3cbaed15..935be765 100644
--- a/external/MbedTLS/MbedTLS.cmake
+++ b/external/MbedTLS/MbedTLS.cmake
@@ -1,96 +1,142 @@
 #-------------------------------------------------------------------------------
-# Copyright (c) 2020-2021, Arm Limited and Contributors. All rights reserved.
+# Copyright (c) 2020-2022, Arm Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
 #-------------------------------------------------------------------------------
 
-# Determine the number of processes to run while running parallel builds.
-# Pass -DPROCESSOR_COUNT=<n> to cmake to override.
-if(NOT DEFINED PROCESSOR_COUNT)
-	include(ProcessorCount)
-	ProcessorCount(PROCESSOR_COUNT)
-	set(PROCESSOR_COUNT ${PROCESSOR_COUNT} CACHE STRING "Number of cores to use for parallel builds.")
-endif()
+set(MBEDTLS_URL "https://github.com/ARMmbed/mbedtls.git"
+		CACHE STRING "Mbed TLS repository URL")
+set(MBEDTLS_REFSPEC "mbedtls-3.0.0"
+		CACHE STRING "Mbed TLS git refspec")
+set(MBEDTLS_SOURCE_DIR "${CMAKE_CURRENT_BINARY_DIR}/_deps/mbedtls-src"
+		CACHE PATH "MbedTLS source directory")
+set(MBEDTLS_INSTALL_DIR "${CMAKE_CURRENT_BINARY_DIR}/mbedtls_install"
+		CACHE PATH "Mbed TLS installation directory")
 
-set(MBEDTLS_URL "https://github.com/ARMmbed/mbedtls.git" CACHE STRING "Mbed TLS repository URL")
-set(MBEDTLS_REFSPEC "mbedtls-3.0.0" CACHE STRING "Mbed TLS git refspec")
-set(MBEDTLS_INSTALL_PATH "${CMAKE_CURRENT_BINARY_DIR}/mbedtls_install" CACHE PATH "Mbed TLS installation directory")
-set(MBEDTLS_PACKAGE_PATH "${MBEDTLS_INSTALL_PATH}/lib/mbedtls/cmake" CACHE PATH "Mbed TLS CMake package directory")
+find_library(MBEDCRYPTO_LIB_FILE
+				NAMES libmbedcrypto.a mbedcrypto.a libmbedcrypto.lib mbedcrypto.lib
+				PATHS ${MBEDTLS_INSTALL_DIR}
+				PATH_SUFFIXES "lib"
+				DOC "Location of mberdrypto library."
+				NO_DEFAULT_PATH
+)
 
-include(FetchContent)
+set(MBEDCRYPTO_LIB_FILE ${MBEDCRYPTO_LIB_FILE})
+unset(MBEDCRYPTO_LIB_FILE CACHE)
 
-# Checking git
-find_program(GIT_COMMAND "git")
-if (NOT GIT_COMMAND)
-	message(FATAL_ERROR "Please install git")
-endif()
+set(MBEDTLS_BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/_deps/mbedtls-build")
 
-# Fetching Mbed TLS
-FetchContent_Declare(
-	mbedtls
-	GIT_REPOSITORY ${MBEDTLS_URL}
-	GIT_TAG ${MBEDTLS_REFSPEC}
-	GIT_SHALLOW TRUE
-)
+# Binary not found and it needs to be built.
+if (NOT MBEDCRYPTO_LIB_FILE)
+	# Determine the number of processes to run while running parallel builds.
+	# Pass -DPROCESSOR_COUNT=<n> to cmake to override.
+	if(NOT DEFINED PROCESSOR_COUNT)
+		include(ProcessorCount)
+		ProcessorCount(PROCESSOR_COUNT)
+		set(PROCESSOR_COUNT ${PROCESSOR_COUNT}
+				CACHE STRING "Number of cores to use for parallel builds.")
+	endif()
 
-# FetchContent_GetProperties exports mbedtls_SOURCE_DIR and mbedtls_BINARY_DIR variables
-FetchContent_GetProperties(mbedtls)
-if(NOT mbedtls_POPULATED)
-	message(STATUS "Fetching Mbed TLS")
-	FetchContent_Populate(mbedtls)
-endif()
+	# See if the source is available locally
+	find_file(MBEDCRYPTO_HEADER_FILE
+		NAMES crypto.h
+		PATHS ${MBEDTLS_SOURCE_DIR}
+		PATH_SUFFIXES "include/psa"
+		NO_DEFAULT_PATH
+	)
+	set(MBEDCRYPTO_HEADER_FILE ${MBEDCRYPTO_HEADER_FILE})
+	unset(MBEDCRYPTO_HEADER_FILE CACHE)
 
-# Convert the include path list to a string. Needed to make parameter passing to
-# Mbed TLS build work fine.
-string(REPLACE ";" "\\;" MBEDTLS_EXTRA_INCLUDES "${MBEDTLS_EXTRA_INCLUDES}")
+	# Source not found, fetch it.
+	if (NOT MBEDCRYPTO_HEADER_FILE)
+		include(FetchContent)
 
-find_package(Python3 COMPONENTS Interpreter)
-if (NOT Python3_Interpreter_FOUND)
-	message(FATAL_ERROR "Python 3 interpreter not found.")
-endif()
+		# Checking git
+		find_program(GIT_COMMAND "git")
+		if (NOT GIT_COMMAND)
+			message(FATAL_ERROR "Please install git")
+		endif()
 
-#Configure Mbed TLS to build only mbedcrypto lib
-execute_process(COMMAND ${Python3_EXECUTABLE} scripts/config.py crypto WORKING_DIRECTORY ${mbedtls_SOURCE_DIR})
-
-# Advertise Mbed TLS as the provider of the psa crypto API
-set(PSA_CRYPTO_API_INCLUDE "${MBEDTLS_INSTALL_PATH}/include" CACHE STRING "PSA Crypto API include path")
-
-#Configure the library
-execute_process(COMMAND
-	${CMAKE_COMMAND}
-		-DENABLE_PROGRAMS=OFF
-		-DENABLE_TESTING=OFF
-		-DUNSAFE_BUILD=ON
-		-DCMAKE_INSTALL_PREFIX=${MBEDTLS_INSTALL_PATH}
-		-DCMAKE_TOOLCHAIN_FILE=${TS_EXTERNAL_LIB_TOOLCHAIN_FILE}
-		-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY
-		-DEXTERNAL_DEFINITIONS=-DMBEDTLS_USER_CONFIG_FILE="${MBEDTLS_USER_CONFIG_FILE}"
-		-DEXTERNAL_INCLUDE_PATHS=${MBEDTLS_EXTRA_INCLUDES}
-		-GUnix\ Makefiles
-		${mbedtls_SOURCE_DIR}
-	WORKING_DIRECTORY
-		${mbedtls_BINARY_DIR}
-	RESULT_VARIABLE _exec_error
-)
+		# Fetching Mbed TLS
+		FetchContent_Declare(
+			mbedtls
+			SOURCE_DIR ${MBEDTLS_SOURCE_DIR}
+			BINARY_DIR ${MBEDTLS_BINARY_DIR}
+			GIT_REPOSITORY ${MBEDTLS_URL}
+			GIT_TAG ${MBEDTLS_REFSPEC}
+			GIT_SHALLOW TRUE
+		)
 
-if (_exec_error)
-	message(FATAL_ERROR "Configuration step of Mbed TLS failed with ${_exec_error}.")
-endif()
+		# FetchContent_GetProperties exports mbedtls_SOURCE_DIR and mbedtls_BINARY_DIR variables
+		FetchContent_GetProperties(mbedtls)
+		# FetchContent_Populate will fail if the source directory is removed since it will try to
+		# do an "update" and not a "populate" action. As a workaround, remove the subbuild directory.
+		# Note: this fix assumes, the default subbuild location is used.
+		file(REMOVE_RECURSE "${CMAKE_CURRENT_BINARY_DIR}/_deps/mbedtls-subbuild")
+
+		# If the source directory has been moved, the binary dir must be regenerated from scratch.
+		file(REMOVE_RECURSE "${MBEDTLS_BINARY_DIR}")
 
-#TODO: add dependency to generated project on this file!
-#TODO: add custom target to rebuild Mbed TLS
+		if (NOT mbedtls_POPULATED)
+			message(STATUS "Fetching Mbed TLS")
+			FetchContent_Populate(mbedtls)
+		endif()
+		set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${MBEDTLS_SOURCE_DIR})
+	endif()
 
-#Build the library
-execute_process(COMMAND
-		${CMAKE_COMMAND} --build ${mbedtls_BINARY_DIR} --parallel ${PROCESSOR_COUNT} --target install
+	# Build mbedcrypto library
+
+	# Convert the include path list to a string. Needed to make parameter passing to
+	# Mbed TLS build work fine.
+	string(REPLACE ";" "\\;" MBEDTLS_EXTRA_INCLUDES "${MBEDTLS_EXTRA_INCLUDES}")
+
+	find_package(Python3 REQUIRED COMPONENTS Interpreter)
+
+	#Configure Mbed TLS to build only mbedcrypto lib
+	execute_process(COMMAND ${Python3_EXECUTABLE} scripts/config.py crypto WORKING_DIRECTORY ${MBEDTLS_SOURCE_DIR})
+
+	# Advertise Mbed TLS as the provider of the psa crypto API
+	set(PSA_CRYPTO_API_INCLUDE "${MBEDTLS_INSTALL_DIR}/include" CACHE STRING "PSA Crypto API include path")
+
+	#Configure the library
+	execute_process(COMMAND
+		${CMAKE_COMMAND} -E env CROSS_COMPILE=${CROSS_COMPILE}
+			${CMAKE_COMMAND}
+				-DENABLE_PROGRAMS=OFF
+				-DENABLE_TESTING=OFF
+				-DUNSAFE_BUILD=ON
+				-DCMAKE_INSTALL_PREFIX=${MBEDTLS_INSTALL_DIR}
+				-DCMAKE_TOOLCHAIN_FILE=${TS_EXTERNAL_LIB_TOOLCHAIN_FILE}
+				-DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY
+				-DEXTERNAL_DEFINITIONS=-DMBEDTLS_USER_CONFIG_FILE="${MBEDTLS_USER_CONFIG_FILE}"
+				-DEXTERNAL_INCLUDE_PATHS=${MBEDTLS_EXTRA_INCLUDES}
+				-GUnix\ Makefiles
+				${MBEDTLS_SOURCE_DIR}
+		WORKING_DIRECTORY
+			${MBEDTLS_BINARY_DIR}
 		RESULT_VARIABLE _exec_error
 	)
-if (_exec_error)
-	message(FATAL_ERROR "Build step of Mbed TLS failed with ${_exec_error}.")
+
+	if (_exec_error)
+		message(FATAL_ERROR "Configuration step of Mbed TLS failed with ${_exec_error}.")
+	endif()
+
+	#Build the library
+	execute_process(COMMAND
+			${CMAKE_COMMAND} --build ${MBEDTLS_BINARY_DIR} --parallel ${PROCESSOR_COUNT} --target install
+			RESULT_VARIABLE _exec_error
+		)
+
+	if (_exec_error)
+		message(FATAL_ERROR "Build step of Mbed TLS failed with ${_exec_error}.")
+	endif()
+
+	set(MBEDCRYPTO_LIB_FILE "${MBEDTLS_INSTALL_DIR}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}mbedcrypto${CMAKE_STATIC_LIBRARY_SUFFIX}")
 endif()
 
 #Create an imported target to have clean abstraction in the build-system.
 add_library(mbedcrypto STATIC IMPORTED)
-set_property(TARGET mbedcrypto PROPERTY IMPORTED_LOCATION "${MBEDTLS_INSTALL_PATH}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}mbedcrypto${CMAKE_STATIC_LIBRARY_SUFFIX}")
-set_property(TARGET mbedcrypto PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${MBEDTLS_INSTALL_PATH}/include")
+set_property(DIRECTORY ${CMAKE_SOURCE_DIR} APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${MBEDCRYPTO_LIB_FILE})
+set_property(TARGET mbedcrypto PROPERTY IMPORTED_LOCATION ${MBEDCRYPTO_LIB_FILE})
+set_property(TARGET mbedcrypto PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${MBEDTLS_INSTALL_DIR}/include")