Doc: Add support for Sphinx documentation build.

Technical documentation of TF-M is captured in GitHub flavored
markdown files. This change add support for building HTML and
PDF output of these files using the Sphinx tool.

Change-Id: I8be11256f2c654c248b1974974a5de6190ca0fc3
Signed-off-by: Gyorgy Szing <Gyorgy.Szing@arm.com>
diff --git a/cmake/Common/Utils.cmake b/cmake/Common/Utils.cmake
index 0c3b0d0..452d0bf 100644
--- a/cmake/Common/Utils.cmake
+++ b/cmake/Common/Utils.cmake
@@ -1,31 +1,41 @@
 #-------------------------------------------------------------------------------
-# Copyright (c) 2017, Arm Limited. All rights reserved.
+# Copyright (c) 2017-2019, Arm Limited. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
 #-------------------------------------------------------------------------------
 
-# Append a value to a string if not already present
+
+#Print a message and exit with failure
 #
-# Append an item to a string if no item with matching key is already on the string.
-# This function's intended purpose is to append unique flags to command line switches.
+#Examples:
+#   failure("Something is wrong!")
+
+function(failure)
+	message(FATAL_ERROR "${ARGN}")
+endfunction()
+
+#Append a value to a string if not already present
 #
-# Examples:
-#  string_append_unique_item(STRING C_FLAGS KEY "--target" VAL "--target=armv8m-arm-none-eabi")
+#Append an item to a string if no item with matching key is already on the string.
+#This function's intended purpose is to append unique flags to command line switches.
 #
-# INPUTS:
-#    STRING  - (mandatory) - name of the string to operate on
-#    KEY   - (mandatory) - string to look for
-#    VAL   - (mandatory) - value to put be added to the string
+#Examples:
+#   string_append_unique_item(STRING C_FLAGS KEY "--target" VAL "--target=armv8m-arm-none-eabi")
 #
-# OUTPUTS
-#    STRING is modified as needed.
+#INPUTS:
+#   STRING  - (mandatory) - name of the string to operate on
+#   KEY     - (mandatory) - string to look for
+#   VAL     - (mandatory) - value to put be added to the string
+#
+#OUTPUTS
+#   STRING is modified as needed.
 #
 function(string_append_unique_item)
 	#Parse our arguments
-	set( _OPTIONS_ARGS )					#No option (on/off) arguments (e.g. IGNORE_CASE)
-	set( _ONE_VALUE_ARGS  STRING KEY VAL)	#Single option arguments (e.g. PATH "./foo/bar")
-	set( _MULTI_VALUE_ARGS )		 		#List arguments (e.g. LANGUAGES C ASM CXX)
+	set( _OPTIONS_ARGS )                    #No option (on/off) arguments (e.g. IGNORE_CASE)
+	set( _ONE_VALUE_ARGS  STRING KEY VAL)   #Single option arguments (e.g. PATH "./foo/bar")
+	set( _MULTI_VALUE_ARGS )                #List arguments (e.g. LANGUAGES C ASM CXX)
 	cmake_parse_arguments(_MY_PARAMS "${_OPTIONS_ARGS}" "${_ONE_VALUE_ARGS}" "${_MULTI_VALUE_ARGS}" ${ARGN} )
 
 	#Check mandatory parameters
@@ -42,11 +52,54 @@
 	if(NOT _MY_PARAMS_VAL)
 		failure("string_append_unique_item(): Missing VAL parameter!")
 	endif()
-    set(_VAL ${_MY_PARAMS_VAL})
+	set(_VAL ${_MY_PARAMS_VAL})
 
-    #Scan the string.
-    STRING(REGEX MATCH "( |^) *${_KEY}" _FOUND "${${_STRING}}")
-    if("${_FOUND}" STREQUAL "")
+	#Scan the string.
+	STRING(REGEX MATCH "( |^) *${_KEY}" _FOUND "${${_STRING}}")
+	if("${_FOUND}" STREQUAL "")
 		set(${_STRING} "${${_STRING}}  ${_VAL}" PARENT_SCOPE)
-    endif()
+	endif()
+endfunction()
+
+
+#Convert \ directory separators to / on windows systems
+#
+#Convert the directory separators to forward slash on windows. Avoid
+#conversion if path contains any forward slashes to avoid mixing up cygwin or
+#mingw paths where an extra caharacter is escaped (i.e. "/c/Program\ Files/")
+#
+#Examples:
+#   set(MY_PATH "C:\foo\bar")
+#   win_fix_dir_sep(PATH MY_PATH)
+#
+#INPUTS:
+#   PATH  - (mandatory) - name of the string variable to operate on
+#
+#OUTPUTS
+#   PATH is modified as needed.
+#
+function(win_fix_dir_sep)
+	#Parse our arguments
+	set( _OPTIONS_ARGS )            #No option (on/off) arguments (e.g. IGNORE_CASE)
+	set( _ONE_VALUE_ARGS  PATH )    #Single option arguments (e.g. PATH "./foo/bar")
+	set( _MULTI_VALUE_ARGS )        #List arguments (e.g. LANGUAGES C ASM CXX)
+	cmake_parse_arguments(_MY_PARAMS "${_OPTIONS_ARGS}" "${_ONE_VALUE_ARGS}" "${_MULTI_VALUE_ARGS}" ${ARGN} )
+
+	#Check mandatory parameters
+	if(NOT _MY_PARAMS_PATH)
+		failure("win_fix_dir_sep(): Missing mandatory parameter PATH!")
+	endif()
+	set(_PATH ${_MY_PARAMS_PATH})
+
+	#To avoid trouble on windows change directory separator.
+	if (CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
+		#Do not convert directory separator if there are forward slashes
+		#present. This is to avoid mixing up escaped characters in cygwin
+		#or mingw paths (i.e. c:/Program\ Files/something)
+		string(FIND "${${_PATH}}" "/" _is_found)
+		if (_is_found LESS 0)
+			string(REPLACE "\\" "/" ${_PATH} "${${_PATH}}")
+			set(${_PATH} "${${_PATH}}" PARENT_SCOPE)
+		endif()
+	endif()
 endfunction()