add_compile_definitions: add new command

This command manages preprocessor definitions at directory level and
supports generator expressions.

Fixes: #15374

2 files changed, 32 insertions, 0 deletions

diff --git a/Tests/CMakeCommands/add_compile_definitions/CMakeLists.txt b/Tests/CMakeCommands/add_compile_definitions/CMakeLists.txt
new file mode 100644
index 0000000..2eb887e
--- /dev/null
+++ b/Tests/CMakeCommands/add_compile_definitions/CMakeLists.txt
@@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 3.1)
+
+project(add_compile_definitions LANGUAGES CXX)
+
+add_compile_definitions(TEST_DEFINITION
+                        $<$<COMPILE_LANGUAGE:CXX>:LANG_$<COMPILE_LANGUAGE>>
+                        $<$<EQUAL:0,1>:UNEXPECTED_DEFINITION>)
+
+add_executable(add_compile_definitions main.cpp)
+
+add_library(imp UNKNOWN IMPORTED)
+get_target_property(_res imp COMPILE_DEFINITIONS)
+if (_res)
+  message(SEND_ERROR "add_compile_definitions populated the COMPILE_DEFINITIONS target property")
+endif()
diff --git a/Tests/CMakeCommands/add_compile_definitions/main.cpp b/Tests/CMakeCommands/add_compile_definitions/main.cpp
new file mode 100644
index 0000000..b382922
--- /dev/null
+++ b/Tests/CMakeCommands/add_compile_definitions/main.cpp
@@ -0,0 +1,17 @@
+
+#ifndef TEST_DEFINITION
+#error Expected TEST_DEFINITION
+#endif
+
+#ifndef LANG_CXX
+#error Expected LANG_CXX
+#endif
+
+#ifdef UNPEXTED_DEFINITION
+#error Unexpected UNPEXTED_DEFINITION
+#endif
+
+int main(void)
+{
+  return 0;
+}