test custom CMake variables in conan generator

variables from https://cmake.org/cmake/help/latest/module/FindLibLZMA.html must be defined

LIBLZMA_HAS_AUTO_DECODER, LIBLZMA_HAS_EASY_ENCODER & LIBLZMA_HAS_LZMA_PRESET are not modeled for the moment

recipes/xz_utils/all/test_package/CMakeLists.txt

@@ -5,3 +5,22 @@ find_package(LibLZMA REQUIRED)
 
 add_executable(${PROJECT_NAME} test_package.c)
 target_link_libraries(${PROJECT_NAME} PRIVATE LibLZMA::LibLZMA)
+
+# Test whether variables from https://cmake.org/cmake/help/latest/module/FindLibLZMA.html
+# are properly defined in conan generators
+set(_custom_vars
+    LIBLZMA_FOUND
+    LibLZMA_INCLUDE_DIRS
+    LIBLZMA_LIBRARIES
+    LIBLZMA_VERSION_MAJOR
+    LIBLZMA_VERSION_MINOR
+    LIBLZMA_VERSION_PATCH
+    LIBLZMA_VERSION_STRING
+)
+foreach(_custom_var ${_custom_vars})
+    if(DEFINED _custom_var)
+        message(STATUS "${_custom_var}: ${${_custom_var}}")
+    else()
+        message(FATAL_ERROR "${_custom_var} not defined")
+    endif()
+endforeach()

recipes/xz_utils/all/test_v1_package/CMakeLists.txt

@@ -8,3 +8,22 @@ find_package(LibLZMA REQUIRED)
 
 add_executable(${PROJECT_NAME} ../test_package/test_package.c)
 target_link_libraries(${PROJECT_NAME} PRIVATE LibLZMA::LibLZMA)
+
+# Test whether variables from https://cmake.org/cmake/help/latest/module/FindLibLZMA.html
+# are properly defined in conan generators
+set(_custom_vars
+    LIBLZMA_FOUND
+    LibLZMA_INCLUDE_DIRS
+    LIBLZMA_LIBRARIES
+    LIBLZMA_VERSION_MAJOR
+    LIBLZMA_VERSION_MINOR
+    LIBLZMA_VERSION_PATCH
+    LIBLZMA_VERSION_STRING
+)
+foreach(_custom_var ${_custom_vars})
+    if(DEFINED _custom_var)
+        message(STATUS "${_custom_var}: ${${_custom_var}}")
+    else()
+        message(FATAL_ERROR "${_custom_var} not defined")
+    endif()
+endforeach()