added option to use system zmq (#1318)

* added option to use system zmq
* added notes in release.txt

CMakeLists.txt

@@ -24,6 +24,7 @@ include(cmake/SlsAddFlag.cmake)
 include(cmake/helpers.cmake)
 
 
+option(SLS_USE_SYSTEM_ZMQ "Use system installed libzmq" OFF)
 
 # Using FetchContent to get libzmq
 include(FetchContent)
@@ -50,6 +51,66 @@ if(NOT PATCH_EXECUTABLE)
     message(FATAL_ERROR "The 'patch' tool is required for patching lib zeromq. Please install it.")
 endif()
 
+if(SLS_USE_SYSTEM_ZMQ)
+    # find_package(ZeroMQ REQUIRED)
+    # 1) Try a CMake package config if available (vcpkg, Homebrew, source builds)
+    #    Many installs export either ZeroMQ::libzmq or libzmq.
+    find_package(ZeroMQ QUIET CONFIG)
+
+    set(ZEROMQ_TARGET "")
+
+    if (TARGET ZeroMQ::libzmq)
+        set(ZEROMQ_TARGET ZeroMQ::libzmq)
+        message(STATUS "Found target: ${ZEROMQ_TARGET} version: ${ZeroMQ_VERSION}")
+    elseif (TARGET libzmq)
+        set(ZEROMQ_TARGET libzmq)
+        message(STATUS "Found target: ${ZEROMQ_TARGET} version: ${ZeroMQ_VERSION}")
+    elseif (TARGET ZeroMQ::ZeroMQ) # rare older naming
+        set(ZEROMQ_TARGET ZeroMQ::ZeroMQ)
+        message(STATUS "Found target: ${ZEROMQ_TARGET} version: ${ZeroMQ_VERSION}")
+    endif()
+
+    # 2) Fallback: use pkg-config hints + manual find_* to create an imported target
+    if (NOT ZEROMQ_TARGET)
+        find_package(PkgConfig QUIET)
+        if (PkgConfig_FOUND)
+            pkg_check_modules(PC_ZeroMQ QUIET libzmq)
+        endif()
+
+        find_path(ZEROMQ_INCLUDE_DIR
+            NAMES zmq.h
+            HINTS ${PC_ZeroMQ_INCLUDE_DIRS}
+        )
+
+        find_library(ZEROMQ_LIBRARY
+            NAMES zmq libzmq
+            HINTS ${PC_ZeroMQ_LIBRARY_DIRS}
+        )
+
+        if (ZEROMQ_INCLUDE_DIR AND ZEROMQ_LIBRARY)
+            add_library(libzmq UNKNOWN IMPORTED)
+            set_target_properties(libzmq PROPERTIES
+            IMPORTED_LOCATION "${ZEROMQ_LIBRARY}"
+            INTERFACE_INCLUDE_DIRECTORIES "${ZEROMQ_INCLUDE_DIR}"
+            )
+            set(ZEROMQ_TARGET libzmq)
+        endif()
+        message(STATUS "ZeroMQ version (pkg-config): ${PC_ZeroMQ_VERSION}")
+        
+    endif()
+
+    # 3) Error out if still not found, with a helpful message
+    if (NOT ZEROMQ_TARGET)
+        message(FATAL_ERROR "ZeroMQ (libzmq) not found. Please install ZeroMQ development files.")
+    endif()
+
+# Use it
+# target_link_libraries(your_target PRIVATE ${ZEROMQ_TARGET})
+
+    message(STATUS "Using system installed libzmq: ${ZeroMQ_LIBRARIES}")
+    message(STATUS "ZeroMQ target: ${ZEROMQ_TARGET}")
+    message(STATUS "ZeroMQ include dirs: ${ZeroMQ_INCLUDE_DIRS}")
+else()
     if(SLS_FETCH_ZMQ_FROM_GITHUB)
         # Opt in to pull down a zmq version from github instead of
         # using the bundled version
@@ -71,6 +132,7 @@ else()
         )
     endif()
 
+
     # Disable unwanted options from libzmq
     set(BUILD_TESTS OFF CACHE BOOL "Switch off libzmq test build")
     set(BUILD_SHARED OFF CACHE BOOL "Switch off libzmq shared libs")
@@ -84,7 +146,6 @@ set(WITH_DOC OFF CACHE BOOL "")
     set(WITH_DOCS OFF CACHE BOOL "")
 
 
-
     # Using GetProperties and Populate to be able to exclude zmq
     # from install (not possible with FetchContent_MakeAvailable(libzmq))
     FetchContent_GetProperties(libzmq)
@@ -93,7 +154,7 @@ if(NOT libzmq_POPULATED)
     add_subdirectory(${libzmq_SOURCE_DIR} ${libzmq_BINARY_DIR} EXCLUDE_FROM_ALL)
     endif()
 
-
+endif()
 
 include(GNUInstallDirs)
 

RELEASE.txt

@@ -26,6 +26,8 @@ This document describes the differences between vx.x.x and vx.0.2
 1 New, Changed or Resolved Features
 =====================================
 
+Added SLS_USE_SYSTEM_ZMQ option (default OFF) to use the libzmq of the host
+instead of the one included in our repo. 
 
  
 

slsReceiverSoftware/CMakeLists.txt

@@ -162,9 +162,17 @@ if (SLS_USE_RECEIVER_BINARIES)
         rt
     PRIVATE
         slsProjectWarnings
-        "$<BUILD_INTERFACE:libzmq-static>"
+        
     )
 
+    #Treat both vendored and system zmq as interface for receiver binaries
+    if(SLS_USE_SYSTEM_ZMQ)
+        message(STATUS "slsFrameSynchronizer ZEROMQ_TARGET=${ZEROMQ_TARGET}")
+        target_link_libraries(slsFrameSynchronizer PRIVATE "${ZEROMQ_TARGET}")
+    else()
+        target_link_libraries(slsFrameSynchronizer PRIVATE "$<BUILD_INTERFACE:libzmq-static>")
+    endif()
+
     install(TARGETS slsReceiver slsMultiReceiver slsFrameSynchronizer
         EXPORT "${TARGETS_EXPORT_NAME}"
         RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}

slsSupportLib/CMakeLists.txt

@@ -93,9 +93,16 @@ target_link_libraries(slsSupportObject
   PRIVATE
     slsProjectWarnings
     md5sls     
-    "$<BUILD_INTERFACE:libzmq-static>"
 )
 
+#Treat both vendored and system zmq as interface for receiver binaries
+if(SLS_USE_SYSTEM_ZMQ)
+    message(STATUS "slsSupportLib using ZEROMQ_TARGET=${ZEROMQ_TARGET}")
+    target_link_libraries(slsSupportObject PRIVATE "${ZEROMQ_TARGET}")
+else()
+    target_link_libraries(slsSupportObject PRIVATE "$<BUILD_INTERFACE:libzmq-static>")
+endif()
+
 if (SLS_USE_TESTS)
     add_subdirectory(tests)
 endif(SLS_USE_TESTS)