From cd526ad54ca2e09cbface17a566fd1a5f76a67ff Mon Sep 17 00:00:00 2001
From: Yury Lysogorskiy <yura.lysogorskii@gmail.com>
Date: Thu, 14 Oct 2021 15:16:48 +0200
Subject: [PATCH] try to find system libyaml-cpp v.0.6.3 library, otherwise use
 downloaded one

---
 cmake/Modules/Packages/ML-PACE.cmake | 48 +++++++++++++++++++---------
 1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/cmake/Modules/Packages/ML-PACE.cmake b/cmake/Modules/Packages/ML-PACE.cmake
index f7ec16d370..6a5d07553d 100644
--- a/cmake/Modules/Packages/ML-PACE.cmake
+++ b/cmake/Modules/Packages/ML-PACE.cmake
@@ -1,22 +1,40 @@
 
-#set(PACELIB_URL "https://github.com/ICAMS/lammps-user-pace/archive/refs/tags/v.2021.9.28.tar.gz" CACHE STRING "URL for PACE evaluator library sources")
-#set(PACELIB_MD5 "f98363bb98adc7295ea63974738c2a1b" CACHE STRING "MD5 checksum of PACE evaluator library tarball")
-#mark_as_advanced(PACELIB_URL)
-#mark_as_advanced(PACELIB_MD5)
+set(PACELIB_URL "https://github.com/ICAMS/lammps-user-pace/archive/refs/tags/v.2021.9.28.upd1.tar.gz" CACHE STRING "URL for PACE evaluator library sources")
+set(PACELIB_MD5 "ec75bc491edd75e10560cdbf129d91a7" CACHE STRING "MD5 checksum of PACE evaluator library tarball")
+mark_as_advanced(PACELIB_URL)
+mark_as_advanced(PACELIB_MD5)
 
 # download library sources to build folder
-#file(DOWNLOAD ${PACELIB_URL} ${CMAKE_BINARY_DIR}/libpace.tar.gz SHOW_PROGRESS EXPECTED_HASH MD5=${PACELIB_MD5})
+file(DOWNLOAD ${PACELIB_URL} ${CMAKE_BINARY_DIR}/libpace.tar.gz SHOW_PROGRESS EXPECTED_HASH MD5=${PACELIB_MD5})
 
 # uncompress downloaded sources
-#execute_process(
-#  COMMAND ${CMAKE_COMMAND} -E remove_directory lammps-user-pace*
-#  COMMAND ${CMAKE_COMMAND} -E tar xzf libpace.tar.gz
-#  WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
-#)
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -E remove_directory lammps-user-pace*
+  COMMAND ${CMAKE_COMMAND} -E tar xzf libpace.tar.gz
+  WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+)
 
 file(GLOB lib-pace ${CMAKE_BINARY_DIR}/lammps-user-pace-*)
-add_subdirectory(${lib-pace}/yaml-cpp build-yaml-cpp)
-set(YAML_CPP_INCLUDE_DIR ${lib-pace}/yaml-cpp/include)
+
+# try to find system libyaml-cpp v.0.6.3 library
+find_package(yaml-cpp 0.6.3 QUIET)
+
+find_path(YAML_CPP_INCLUDE_DIR
+        NAMES yaml.h
+        PATHS ${YAML_CPP_INCLUDE_DIRS})
+
+find_library(YAML_CPP_LIBRARY
+        NAMES yaml-cpp
+        PATHS ${YAML_CPP_LIBRARY_DIRS})
+
+# if system library not found - using downloaded
+if(${YAML_CPP_LIBRARY} STREQUAL "" OR ${YAML_CPP_INCLUDE_DIR} STREQUAL "" OR
+        ${YAML_CPP_INCLUDE_DIR} STREQUAL "YAML_CPP_INCLUDE_DIR-NOTFOUND")
+    message("-- Library yaml-fcc v0.6.3  not found, using downloaded copy")
+    add_subdirectory(${lib-pace}/yaml-cpp build-yaml-cpp)
+    set(YAML_CPP_INCLUDE_DIR ${lib-pace}/yaml-cpp/include)
+    set(YAML_CPP_LIBRARY yaml-cpp-pace)
+endif()
 
 file(GLOB PACE_EVALUATOR_INCLUDE_DIR ${lib-pace}/ML-PACE)
 file(GLOB PACE_EVALUATOR_SOURCES ${lib-pace}/ML-PACE/*.cpp)
@@ -24,8 +42,8 @@ list(FILTER PACE_EVALUATOR_SOURCES EXCLUDE REGEX pair_pace.cpp)
 
 add_library(pace STATIC ${PACE_EVALUATOR_SOURCES})
 set_target_properties(pace PROPERTIES CXX_EXTENSIONS ON OUTPUT_NAME lammps_pace${LAMMPS_MACHINE})
-target_include_directories(pace PUBLIC ${PACE_EVALUATOR_INCLUDE_DIR} ${YAML_CPP_INCLUDE_DIR})
+target_include_directories(pace PRIVATE ${YAML_CPP_INCLUDE_DIR})
+target_include_directories(pace PUBLIC ${PACE_EVALUATOR_INCLUDE_DIR})
 
 target_link_libraries(lammps PRIVATE pace)
-target_link_libraries(lammps PRIVATE yaml-cpp-pace)
-
+target_link_libraries(lammps PRIVATE ${YAML_CPP_LIBRARY})
\ No newline at end of file