Merge pull request #517 from ssrobins/check-conan-version

Check required Conan version

conan_support.cmake

@@ -1,3 +1,6 @@
+set(CONAN_MINIMUM_VERSION 2.0.2)
+
+
 function(detect_os OS)
     # it could be cross compilation
     message(STATUS "CMake-Conan: cmake_system_name=${CMAKE_SYSTEM_NAME}")
@@ -163,10 +166,48 @@ function(conan_install)
 endfunction()
 
 
+function(conan_get_version conan_command conan_current_version)
+    execute_process(
+        COMMAND ${conan_command} --version
+        OUTPUT_VARIABLE conan_output
+        RESULT_VARIABLE conan_result
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+    )
+    if(conan_result)
+        message(FATAL_ERROR "CMake-Conan: Error when trying to run Conan")
+    endif()
+
+    string(REGEX MATCH "[0-9]+\\.[0-9]+\\.[0-9]+" conan_version ${conan_output})
+    set(${conan_current_version} ${conan_version} PARENT_SCOPE)
+endfunction()
+
+
+function(conan_version_check)
+    set(options )
+    set(oneValueArgs MINIMUM CURRENT)
+    set(multiValueArgs )
+    cmake_parse_arguments(CONAN_VERSION_CHECK
+        "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+    if(NOT CONAN_VERSION_CHECK_MINIMUM)
+        message(FATAL_ERROR "CMake-Conan: Required parameter MINIMUM not set!")
+    endif()
+        if(NOT CONAN_VERSION_CHECK_CURRENT)
+        message(FATAL_ERROR "CMake-Conan: Required parameter CURRENT not set!")
+    endif()
+
+    if(CONAN_VERSION_CHECK_CURRENT VERSION_LESS CONAN_VERSION_CHECK_MINIMUM)
+        message(FATAL_ERROR "CMake-Conan: Conan version must be ${CONAN_VERSION_CHECK_MINIMUM} or later")
+    endif()
+endfunction()
+
+
 macro(conan_provide_dependency package_name)
     get_property(CONAN_INSTALL_SUCCESS GLOBAL PROPERTY CONAN_INSTALL_SUCCESS)
     if(NOT CONAN_INSTALL_SUCCESS)
         find_program(CONAN_COMMAND "conan" REQUIRED)
+        conan_get_version(${CONAN_COMMAND} CONAN_CURRENT_VERSION)
+        conan_version_check(MINIMUM ${CONAN_MINIMUM_VERSION} CURRENT ${CONAN_CURRENT_VERSION})
         message(STATUS "CMake-Conan: first find_package() found. Installing dependencies with Conan")
         conan_profile_detect_default()
         detect_host_profile(${CMAKE_BINARY_DIR}/conan_host_profile)