Build: Add MBEDTLS_TARGET_PREFIX

Allows required targets to have prefixes added to them, so that external
projects can avoid target names clashing.

Signed-off-by: Raef Coles <raef.coles@arm.com>
diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index 4444b98..f0315f7 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -150,18 +150,31 @@
     message(FATAL_ERROR "Need to choose static or shared mbedtls build!")
 endif(NOT USE_STATIC_MBEDTLS_LIBRARY AND NOT USE_SHARED_MBEDTLS_LIBRARY)
 
-set(target_libraries "mbedcrypto" "mbedx509" "mbedtls")
+set(mbedtls_target    "${MBEDTLS_TARGET_PREFIX}mbedtls")
+set(mbedx509_target   "${MBEDTLS_TARGET_PREFIX}mbedx509")
+set(mbedcrypto_target "${MBEDTLS_TARGET_PREFIX}mbedcrypto")
+
+set(mbedtls_target    ${mbedtls_target}    PARENT_SCOPE)
+set(mbedx509_target   ${mbedx509_target}   PARENT_SCOPE)
+set(mbedcrypto_target ${mbedcrypto_target} PARENT_SCOPE)
+
+if (USE_STATIC_MBEDTLS_LIBRARY)
+    set(mbedtls_static_target    ${mbedtls_target})
+    set(mbedx509_static_target   ${mbedx509_target})
+    set(mbedcrypto_static_target ${mbedcrypto_target})
+endif()
+
+set(target_libraries ${mbedcrypto_target} ${mbedx509_target} ${mbedtls_target})
 
 if(USE_STATIC_MBEDTLS_LIBRARY AND USE_SHARED_MBEDTLS_LIBRARY)
-    set(mbedtls_static_target "mbedtls_static")
-    set(mbedx509_static_target "mbedx509_static")
-    set(mbedcrypto_static_target "mbedcrypto_static")
+    string(APPEND mbedtls_static_target    "_static")
+    string(APPEND mbedx509_static_target   "_static")
+    string(APPEND mbedcrypto_static_target "_static")
+
     list(APPEND target_libraries
-        "mbedcrypto_static" "mbedx509_static" "mbedtls_static")
-elseif(USE_STATIC_MBEDTLS_LIBRARY)
-    set(mbedtls_static_target "mbedtls")
-    set(mbedx509_static_target "mbedx509")
-    set(mbedcrypto_static_target "mbedcrypto")
+        ${mbedcrypto_static_target}
+        ${mbedx509_static_target}
+        ${mbedtls_static_target})
 endif()
 
 if(USE_STATIC_MBEDTLS_LIBRARY)
@@ -179,17 +192,17 @@
 endif(USE_STATIC_MBEDTLS_LIBRARY)
 
 if(USE_SHARED_MBEDTLS_LIBRARY)
-    add_library(mbedcrypto SHARED ${src_crypto})
-    set_target_properties(mbedcrypto PROPERTIES VERSION 2.24.0 SOVERSION 5)
-    target_link_libraries(mbedcrypto ${libs})
+    add_library(${mbedcrypto_target} SHARED ${src_crypto})
+    set_target_properties(${mbedcrypto_target} PROPERTIES VERSION 2.24.0 SOVERSION 5)
+    target_link_libraries(${mbedcrypto_target} ${libs})
 
-    add_library(mbedx509 SHARED ${src_x509})
-    set_target_properties(mbedx509 PROPERTIES VERSION 2.24.0 SOVERSION 1)
-    target_link_libraries(mbedx509 ${libs} mbedcrypto)
+    add_library(${mbedx509_target} SHARED ${src_x509})
+    set_target_properties(${mbedx509_target} PROPERTIES VERSION 2.24.0 SOVERSION 1)
+    target_link_libraries(${mbedx509_target} ${libs} ${mbedcrypto_target})
 
-    add_library(mbedtls SHARED ${src_tls})
-    set_target_properties(mbedtls PROPERTIES VERSION 2.24.0 SOVERSION 13)
-    target_link_libraries(mbedtls ${libs} mbedx509)
+    add_library(${mbedtls_target} SHARED ${src_tls})
+    set_target_properties(${mbedtls_target} PROPERTIES VERSION 2.24.0 SOVERSION 13)
+    target_link_libraries(${mbedtls_target} ${libs} ${mbedx509_target})
 endif(USE_SHARED_MBEDTLS_LIBRARY)
 
 foreach(target IN LISTS target_libraries)
@@ -210,7 +223,9 @@
             PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ)
 endforeach(target)
 
-add_custom_target(lib DEPENDS mbedcrypto mbedx509 mbedtls)
+set(lib_target "${MBEDTLS_TARGET_PREFIX}lib")
+
+add_custom_target(${lib_target} DEPENDS ${mbedcrypto_target} ${mbedx509_target} ${mbedtls_target})
 if(USE_STATIC_MBEDTLS_LIBRARY AND USE_SHARED_MBEDTLS_LIBRARY)
-    add_dependencies(lib mbedcrypto_static mbedx509_static mbedtls_static)
+    add_dependencies(${lib_target} ${mbedcrypto_static_target} ${mbedx509_static_target} ${mbedtls_static_target})
 endif()