cmake: Make max retransmit configurable with CMake

The CMake variable `WAKAAMA_COAP_DEFAULT_MAX_RETRANSMIT` can be used to
configure the max number of retransmissions.

Author: LukasWoodtli

README.md

@@ -84,6 +84,7 @@ The following data formats are configurable for Wakaama:
 - WAKAAMA_COAP_RAW_BLOCK1_REQUESTS For low memory client devices where it is not possible to keep a large post or put request in memory to be parsed (typically a firmware write).
   This option enable each unprocessed block 1 payload to be passed to the application, typically to be stored to a flash memory.
 - WAKAAMA_COAP_DEFAULT_BLOCK_SIZE CoAP block size used by CoAP layer when performing block-wise transfers. Possible values: 16, 32, 64, 128, 256, 512 and 1024. Defaults to 1024.
+- WAKAAMA_COAP_DEFAULT_MAX_RETRANSMIT The maximum number of retransmissions used for confirmable messages.
 
 
 ### Logging

wakaama.cmake

@@ -44,6 +44,12 @@ set_property(
              1024
 )
 
+# The maximum number of retransmissions used for confirmable messages.
+set(WAKAAMA_COAP_DEFAULT_MAX_RETRANSMIT
+    4
+    CACHE STRING "Default CoAP max retransmissions"
+)
+
 # Logging
 set(WAKAAMA_LOG_LEVEL
     LOG_DISABLED
@@ -144,6 +150,8 @@ function(set_coap_defines)
     endif()
 
     target_compile_definitions(${target} PUBLIC LWM2M_COAP_DEFAULT_BLOCK_SIZE=${WAKAAMA_COAP_DEFAULT_BLOCK_SIZE})
+
+    target_compile_definitions(${target} PUBLIC LWM2M_COAP_DEFAULT_MAX_RETRANSMIT=${WAKAAMA_COAP_DEFAULT_MAX_RETRANSMIT})
 endfunction()
 
 # Set the defines for logging configuration
@@ -239,17 +247,6 @@ function(target_sources_wakaama target)
         message(STATUS "${target}: Default CoAP block size not set, using ${LWM2M_COAP_DEFAULT_BLOCK_SIZE}")
     endif()
 
-    # LWM2M_COAP_DEFAULT_MAX_RETRANSMIT is needed by source files -> always set it
-    if(NOT CURRENT_TARGET_COMPILE_DEFINITIONS MATCHES "LWM2M_COAP_DEFAULT_MAX_RETRANSMIT=")
-        target_compile_definitions(
-            ${target} PRIVATE "LWM2M_COAP_DEFAULT_MAX_RETRANSMIT=${LWM2M_COAP_DEFAULT_MAX_RETRANSMIT}"
-        )
-        message(
-            STATUS
-                "${target}: Default CoAP max retransmission count not set, using ${LWM2M_COAP_DEFAULT_MAX_RETRANSMIT}"
-        )
-    endif()
-
     # Detect invalid configuration already during CMake run
     if(NOT CURRENT_TARGET_COMPILE_DEFINITIONS MATCHES "LWM2M_SERVER_MODE|LWM2M_BOOTSTRAP_SERVER_MODE|LWM2M_CLIENT_MODE")
         message(FATAL_ERROR "${target}: At least one mode (client, server, bootstrap server) must be enabled!")
@@ -350,9 +347,3 @@ set(LWM2M_COAP_DEFAULT_BLOCK_SIZE
     1024
     CACHE STRING "Default CoAP block size; Used if not set on a per-target basis"
 )
-
-# The maximum number of retransmissions used for confirmable messages.
-set(LWM2M_COAP_DEFAULT_MAX_RETRANSMIT
-    4
-    CACHE STRING "Default CoAP max retransmissions; Used if not set on a per-target basis"
-)