Merge pull request #75 from eclipse-zenoh/cmake_3_16

Fixes for cmake 3.16 support
eclipse-zenoh · Sep 21, 2023 · 9fec0f4 · 9fec0f4
2 parents e5e333e + 024da6d
commit 9fec0f4
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Showing 4 changed files with 63 additions and 17 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -7,8 +7,10 @@ project(
 	LANGUAGES C CXX
 )
 
+set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake ${CMAKE_MODULE_PATH})
+include(helpers)
+
 if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
-	include(cmake/helpers.cmake)
 	enable_testing()
 	set_default_build_type(Release)
 	configure_include_project(ZENOHCXX_ZENOHPICO zenohpico zenohpico "../zenoh-pico" zenohpico "https://github.com/eclipse-zenoh/zenoh-pico" "")

diff --git a/cmake/helpers.cmake b/cmake/helpers.cmake
@@ -18,11 +18,6 @@
 # functions and macros definitions
 #
 
-#
-# Allow to find cmake modules in this directory
-#
-set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}" ${CMAKE_MODULE_PATH})
-
 
 #
 # Show VARIABLE = value on configuration stage
@@ -66,6 +61,35 @@ function(debug_print var)
     )
 endfunction()
 
+
+#
+# initialize `dstvar` with `$<IF:genexpr_condition,srcvar_true,srcvar_false>` generator expression
+# only if `srcvar_true` and `srcvar_false` are actually different and if multi-config generator is used.
+# Otherwise `dstvar` is initialized with `srcvar_true` or `srcvar_false` value depending on `var_condition` variable.
+#
+# This is convenient to 
+# - remove visual garbage when generator expressions actually does nothing
+# - avoid using generator expression if single-config generator is used
+#
+function(set_genexpr_condition dstvar var_condition genexpr_condition srcvar_true srcvar_false)
+    get_property(GENERATOR_IS_MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
+	if(GENERATOR_IS_MULTI_CONFIG AND NOT("${srcvar_true}" STREQUAL "${srcvar_false}"))
+        list(JOIN srcvar_true "$<SEMICOLON>" srcvar_true)
+        list(JOIN srcvar_false "$<SEMICOLON>" srcvar_false)
+        set(${dstvar} $<IF:${genexpr_condition},${srcvar_true},${srcvar_false}> PARENT_SCOPE)
+    else()
+        if(DEFINED ${var_condition})
+            if (${${var_condition}})
+                set(${dstvar} "${srcvar_true}" PARENT_SCOPE)
+            else()
+                set(${dstvar} "${srcvar_false}" PARENT_SCOPE)
+            endif()
+        else()
+            set(${dstvar} "${srcvar_false}" PARENT_SCOPE)
+        endif()
+    endif()
+endfunction()
+
 #
 # Copy necessary dlls to target runtime directory
 #
@@ -84,6 +108,12 @@ endfunction()
 macro(set_default_build_type config_type)
     get_property(GENERATOR_IS_MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
     if(GENERATOR_IS_MULTI_CONFIG)
+        if(${CMAKE_VERSION} VERSION_LESS "3.20") 
+            message(FATAL_ERROR "\n"
+                "You are using multi config generator '${CMAKE_GENERATOR}' and cmake ${CMAKE_VERSION}\n"
+                "Unfortuinately multi config generators are not supported by this script for CMake < 3.20 due to insufficient support of generator expressions in old CMake versions\n"
+                "Please consider upgrading your cmake or switching to single-config generator with `-G` option, like `cmake -G Ninja` or `cmake -G \"Unix Makefiles\"\n")
+        endif()
         if(NOT DEFINED CMAKE_BUILD_TYPE) # if user passed argument '-DCMAKE_BUILD_TYPE=value', use it
             set(CMAKE_BUILD_TYPE ${config_type})
         endif()
@@ -103,24 +133,29 @@ macro(set_default_build_type config_type)
         if(CMAKE_BUILD_TYPE STREQUAL "")
             set(CMAKE_BUILD_TYPE ${config_type})
         endif()
-         status_print(CMAKE_BUILD_TYPE)
+        status_print(CMAKE_BUILD_TYPE)
     endif()
 endmacro()
 
 #
 # Add default set of libraries depending on platform
 #
-function(add_platfrom_libraries target)
+function(get_required_static_libs variable)
+    # actually required list of libraries can be obtained by executing
+    # cargo rustc -- --print native-static-libs
+    # This command is not intented to be used in autoamted build yet,
+    # so actaul libraries are hardcoded for now
 	if(APPLE)
 		find_library(FFoundation Foundation)
 		find_library(FSecurity Security)
-		target_link_libraries(${target} PUBLIC ${FFoundation} ${FSecurity})
+        set(native_static_libs ${FFoundation} ${FSecurity})
 	elseif(UNIX)
-		target_link_libraries(${target} PUBLIC rt pthread m dl)
+        set(native_static_libs rt pthread m dl)
 	elseif(WIN32)
-		target_link_libraries(${target} PUBLIC ws2_32 crypt32 secur32 bcrypt ncrypt userenv ntdll iphlpapi runtimeobject)
+        set(native_static_libs ws2_32 crypt32 secur32 bcrypt ncrypt userenv ntdll iphlpapi runtimeobject)
 	endif()
-
+    set(${variable} ${native_static_libs} PARENT_SCOPE)
+    message(STATUS "${variable} = ${native_static_libs}")
 endfunction()
 
 #
@@ -186,14 +221,21 @@ endmacro()
 function(include_project)
     __include_project(${ARGN})
     # recover functions which may be replaced by included project
-    include(${CMAKE_CURRENT_FUNCTION_LIST_FILE})
+    # Using here the policy https://cmake.org/cmake/help/v3.16/policy/CMP0017.html#policy:CMP0017
+    include(helpers OPTIONAL RESULT_VARIABLE helpers_included)
+    if (NOT helpers_included)
+        message(FATAL_ERROR "Failed to reinclude helpers.cmake after processing external project\n"
+        "You have to include helpers.cmake as a module to make the `include` operation above work:\n"
+        "   set(CMAKE_MODULE_PATH \"path-to-this-helpers-cmake\" \${CMAKE_MODULE_PATH})\n"
+        "   include(helpers)\n")
+    endif()
 endfunction()
 
-function(__include_project project_name)
+function(include_project project_name)
     include(FetchContent)
     include(CMakeParseArguments)
     cmake_parse_arguments(PARSE_ARGV 1 "ARG" "QUIET" "TARGET;PATH;PACKAGE;GIT_URL;GIT_TAG" "")
-    unset_if_empty(ARG_PATH ARG_TARGET ARG_PACKAGE ARG_GIT_URL)
+    unset_if_empty(ARG_PATH ARG_TARGET ARG_PACKAGE ARG_GIT_URL ARG_GIT_TAG)
     if(NOT DEFINED ARG_TARGET)
         message(FATAL_ERROR "Non-empty TARGET parameter is required")
     endif()

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
@@ -2,7 +2,8 @@ if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
     # Settings when 'examples' is the root projet
     cmake_minimum_required(VERSION 3.16)
     project(zenohcxx_examples LANGUAGES C CXX)
-    include(../cmake/helpers.cmake)
+	set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../cmake ${CMAKE_MODULE_PATH})
+    include(helpers)
     set_default_build_type(Release)
     configure_include_project(ZENOHCXX_ZENOHC zenohc zenohc::lib "../../zenoh-c" zenohc "https://github.com/eclipse-zenoh/zenoh-c" "")
     configure_include_project(ZENOHPICO zenohpico zenohpico "../../zenoh-pico" zenohc "https://github.com/eclipse-zenoh/zenoh-pico" "")

diff --git a/install/CMakeLists.txt b/install/CMakeLists.txt
@@ -8,7 +8,8 @@ if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
         HOMEPAGE_URL "https://github.com/eclipse-zenoh/zenoh-cpp"
         LANGUAGES C CXX
     )
-    include(../cmake/helpers.cmake)
+    set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../cmake ${CMAKE_MODULE_PATH})
+    include(helpers)
     include_project(zenohcxx TARGET zenohcxx PATH "..")
 else()
     message(STATUS "zenoh-cpp install")