From 59c389a91cfe91eebed9c36887fa2a3eca4cbd6f Mon Sep 17 00:00:00 2001
From: Christian Marangi <ansuelsmth@gmail.com>
Date: Mon, 24 Nov 2025 18:53:28 +0100
Subject: [PATCH] [rest] Permit to externally provide cJSON library

Permit to externally provide cJSON library if found with PKGConfig.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 src/rest/CMakeLists.txt    | 12 +++++++++++-
 third_party/CMakeLists.txt |  5 ++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

--- a/src/rest/CMakeLists.txt
+++ b/src/rest/CMakeLists.txt
@@ -36,11 +36,22 @@ add_library(otbr-rest
     response.cpp
 )
 
+if (CJSON_FOUND)
+    set(CJSON_LIB_TARGETS ${CJSON_LINK_LIBRARIES})
+else()
+    set(CJSON_LIB_TARGETS cjson)
+endif()
+
+target_include_directories(otbr-rest
+    PRIVATE
+        ${CJSON_INCLUDE_DIRS}
+)
+
 target_link_libraries(otbr-rest
     PUBLIC
         http_parser
     PRIVATE
-        cjson
+        ${CJSON_LIB_TARGETS}
         otbr-config
         otbr-utils
         openthread-ftd
--- a/third_party/CMakeLists.txt
+++ b/third_party/CMakeLists.txt
@@ -28,6 +28,13 @@
 
 add_subdirectory(openthread)
 if(OTBR_REST)
-    add_subdirectory(cJSON)
+    pkg_check_modules(CJSON libcjson)
+    if (CJSON_FOUND)
+        set(CJSON_FOUND ${CJSON_FOUND} PARENT_SCOPE)
+        set(CJSON_INCLUDE_DIRS ${CJSON_INCLUDE_DIRS} PARENT_SCOPE)
+        set(CJSON_LINK_LIBRARIES ${CJSON_LINK_LIBRARIES} PARENT_SCOPE)
+    else()
+        add_subdirectory(cJSON)
+    endif()
     add_subdirectory(http-parser)
 endif()