From c2566eac21dcc0fce1102da051c6bcaf7149d01c Mon Sep 17 00:00:00 2001
From: Nicolas Cornu <nicolas.cornu@epfl.ch>
Date: Tue, 6 Feb 2024 19:49:27 +0100
Subject: [PATCH] Cmake: Create 'get_link_libraries' to make it recursive
 (#2709)

The issue was spotted when building with Caliper master. It returns MPI as a target and hence we need this fix.
---
 cmake/CMakeListsNrnMech.cmake | 94 ++++++++++++++++++++---------------
 1 file changed, 53 insertions(+), 41 deletions(-)

diff --git a/cmake/CMakeListsNrnMech.cmake b/cmake/CMakeListsNrnMech.cmake
index 38ea5084c8..6d53842273 100644
--- a/cmake/CMakeListsNrnMech.cmake
+++ b/cmake/CMakeListsNrnMech.cmake
@@ -23,48 +23,60 @@ endif()
 # Interview might have linked to libnrniv but we don't want to link to special
 list(REMOVE_ITEM NRN_LINK_LIBS "interviews")
 
-# CMake does some magic to transform sys libs to -l<libname>. We replicate it
-foreach(link_lib ${NRN_LINK_LIBS})
-  # skip static readline library as it will be linked to nrniv (e.g. with wheel) also stub libraries
-  # from OSX can be skipped
-  if("${link_lib}" MATCHES "(libreadline.a|/*.tbd)")
-    continue()
-  endif()
+function(get_link_libraries libs)
+  # CMake does some magic to transform sys libs to -l<libname>. We replicate it
+  foreach(link_lib ${libs})
+    # skip static readline library as it will be linked to nrniv (e.g. with wheel) also stub
+    # libraries from OSX can be skipped
+    if("${link_lib}" MATCHES "(libreadline.a|/*.tbd)")
+      continue()
+    endif()
 
-  get_filename_component(dir_path ${link_lib} DIRECTORY)
-  if(TARGET ${link_lib})
-    get_property(
-      link_flag
-      TARGET ${link_lib}
-      PROPERTY INTERFACE_LINK_LIBRARIES)
-    set(description
-        "Extracting link flags from target '${link_lib}', beware that this can be fragile.")
-    # Not use it yet because it can be generator expressions get_property(compile_flag TARGET
-    # ${link_lib} PROPERTY INTERFACE_COMPILE_OPTIONS) string(APPEND NRN_COMPILE_DEFS
-    # ${compile_flag})
-  elseif(NOT dir_path)
-    set(link_flag "-l${link_lib}")
-    set(description
-        "Generating link flags from name '${link_lib}', beware that this can be fragile.")
-    # avoid library paths from special directory /nrnwheel which used to build wheels under docker
-    # container
-  elseif("${dir_path}" MATCHES "^/nrnwheel")
-    continue()
-  elseif("${dir_path}" MATCHES "^(/lib|/lib64|/usr/lib|/usr/lib64)$")
-    # NAME_WLE not avaialble with CMake version < 3.14
-    get_filename_component(libname ${link_lib} NAME)
-    string(REGEX REPLACE "\\.[^.]*$" "" libname_wle ${libname})
-    string(REGEX REPLACE "^lib" "" libname_wle ${libname_wle})
-    set(link_flag "-l${libname_wle}")
-    set(description
-        "Extracting link flags from path '${link_lib}', beware that this can be fragile.")
-  else()
-    set(link_flag "${link_lib} -Wl,-rpath,${dir_path}")
-    set(description "Generating link flags from path ${link_lib}")
-  endif()
-  message(NOTICE "${description} Got: ${link_flag}")
-  string(APPEND NRN_LINK_DEFS " ${link_flag}")
-endforeach()
+    get_filename_component(dir_path ${link_lib} DIRECTORY)
+    if(TARGET ${link_lib})
+      get_property(
+        sublink_flag
+        TARGET ${link_lib}
+        PROPERTY INTERFACE_LINK_LIBRARIES)
+      set(description
+          "Extracting link flags from target '${link_lib}', beware that this can be fragile.")
+      # Not use it yet because it can be generator expressions get_property(compile_flag TARGET
+      # ${link_lib} PROPERTY INTERFACE_COMPILE_OPTIONS) string(APPEND NRN_COMPILE_DEFS
+      # ${compile_flag})
+      foreach(sublink_lib ${sublink_flag})
+        if(TARGET ${sublink_lib})
+          message(NOTICE "For '${link_lib}' going to see TARGET '${sublink_lib}' recursively.")
+          get_link_libraries(${sublink_lib})
+        else()
+          set(link_flag "${link_flag} ${sublink_flag}")
+        endif()
+      endforeach()
+    elseif(NOT dir_path)
+      set(link_flag "-l${link_lib}")
+      set(description
+          "Generating link flags from name '${link_lib}', beware that this can be fragile.")
+      # avoid library paths from special directory /nrnwheel which used to build wheels under docker
+      # container
+    elseif("${dir_path}" MATCHES "^/nrnwheel")
+      continue()
+    elseif("${dir_path}" MATCHES "^(/lib|/lib64|/usr/lib|/usr/lib64)$")
+      # NAME_WLE not avaialble with CMake version < 3.14
+      get_filename_component(libname ${link_lib} NAME)
+      string(REGEX REPLACE "\\.[^.]*$" "" libname_wle ${libname})
+      string(REGEX REPLACE "^lib" "" libname_wle ${libname_wle})
+      set(link_flag "-l${libname_wle}")
+      set(description
+          "Extracting link flags from path '${link_lib}', beware that this can be fragile.")
+    else()
+      set(link_flag "${link_lib} -Wl,-rpath,${dir_path}")
+      set(description "Generating link flags from path ${link_lib}")
+    endif()
+    message(NOTICE "${description} Got: ${link_flag}")
+    string(APPEND NRN_LINK_DEFS " ${link_flag}")
+  endforeach()
+endfunction(get_link_libraries)
+
+get_link_libraries("${NRN_LINK_LIBS}")
 
 # Compiler flags depending on cmake build type from BUILD_TYPE_<LANG>_FLAGS
 string(TOUPPER "${CMAKE_BUILD_TYPE}" _BUILD_TYPE)