Merge pull request #3610 from akohlmey/cmake-enable-pkg-deps

Auto-enable packages with CMake if needed

cmake/Modules/LAMMPSUtils.cmake

@@ -99,8 +99,15 @@ function(check_for_autogen_files source_dir)
 endfunction()
 
 macro(pkg_depends PKG1 PKG2)
-  if(PKG_${PKG1} AND NOT (PKG_${PKG2} OR BUILD_${PKG2}))
-    message(FATAL_ERROR "The ${PKG1} package needs LAMMPS to be built with the ${PKG2} package")
+  if(DEFINED BUILD_${PKG2})
+    if(PKG_${PKG1} AND NOT BUILD_${PKG2})
+      message(FATAL_ERROR "The ${PKG1} package needs LAMMPS to be built with -D BUILD_${PKG2}=ON")
+    endif()
+  elseif(DEFINED PKG_${PKG2})
+    if(PKG_${PKG1} AND NOT PKG_${PKG2})
+      message(WARNING "The ${PKG1} package depends on the ${PKG2} package. Enabling it.")
+      set(PKG_${PKG2} ON CACHE BOOL "" FORCE)
+    endif()
   endif()
 endmacro()
 

cmake/Modules/Packages/COMPRESS.cmake

@@ -1,4 +1,9 @@
-find_package(ZLIB REQUIRED)
+find_package(ZLIB)
+if(NOT ZLIB_FOUND)
+  message(WARNING "No Zlib development support found. Disabling COMPRESS package...")
+  set(PKG_COMPRESS OFF CACHE BOOL "" FORCE)
+  return()
+endif()
 target_link_libraries(lammps PRIVATE ZLIB::ZLIB)
 
 find_package(PkgConfig QUIET)