Add target_compile_features command.

This can be used to set the compiler features required by particular
targets. An error is issued at CMake time if the compiler does not
support the required feature. If a language dialect flag is required
by the features used, that will be added automatically.

Base the target_compile_features command on cmTargetPropCommandBase. This
gives us 'free' handling of IMPORTED, ALIAS, INTERFACE, non-compilable
and missing targets.

6 files changed, 49 insertions, 0 deletions

diff --git a/Tests/CMakeCommands/target_compile_features/CMakeLists.txt b/Tests/CMakeCommands/target_compile_features/CMakeLists.txt
new file mode 100644
index 0000000..ad76411
--- /dev/null
+++ b/Tests/CMakeCommands/target_compile_features/CMakeLists.txt
@@ -0,0 +1,17 @@
+cmake_minimum_required(VERSION 3.0)
+project(target_compile_features)
+
+set(CMAKE_VERBOSE_MAKEFILE ON)
+
+add_executable(target_compile_features main.cpp)
+target_compile_features(target_compile_features
+  PRIVATE cxx_auto_type
+)
+
+add_library(lib_auto_type lib_auto_type.cpp)
+target_compile_features(lib_auto_type
+  PUBLIC cxx_auto_type
+)
+
+add_executable(lib_user lib_user.cpp)
+target_link_libraries(lib_user lib_auto_type)
diff --git a/Tests/CMakeCommands/target_compile_features/dummy.cpp b/Tests/CMakeCommands/target_compile_features/dummy.cpp
new file mode 100644
index 0000000..341aaaf
--- /dev/null
+++ b/Tests/CMakeCommands/target_compile_features/dummy.cpp
@@ -0,0 +1,5 @@
+
+int main(int, char **)
+{
+  return 0;
+}
diff --git a/Tests/CMakeCommands/target_compile_features/lib_auto_type.cpp b/Tests/CMakeCommands/target_compile_features/lib_auto_type.cpp
new file mode 100644
index 0000000..71b2215
--- /dev/null
+++ b/Tests/CMakeCommands/target_compile_features/lib_auto_type.cpp
@@ -0,0 +1,6 @@
+
+int getAutoTypeImpl()
+{
+  auto i = 0;
+  return i;
+}
diff --git a/Tests/CMakeCommands/target_compile_features/lib_auto_type.h b/Tests/CMakeCommands/target_compile_features/lib_auto_type.h
new file mode 100644
index 0000000..c825b10
--- /dev/null
+++ b/Tests/CMakeCommands/target_compile_features/lib_auto_type.h
@@ -0,0 +1,8 @@
+
+int getAutoTypeImpl();
+
+int getAutoType()
+{
+  auto i = getAutoTypeImpl();
+  return i;
+}
diff --git a/Tests/CMakeCommands/target_compile_features/lib_user.cpp b/Tests/CMakeCommands/target_compile_features/lib_user.cpp
new file mode 100644
index 0000000..976068a
--- /dev/null
+++ b/Tests/CMakeCommands/target_compile_features/lib_user.cpp
@@ -0,0 +1,7 @@
+
+#include "lib_auto_type.h"
+
+int main(int argc, char **argv)
+{
+  return getAutoType();
+}
diff --git a/Tests/CMakeCommands/target_compile_features/main.cpp b/Tests/CMakeCommands/target_compile_features/main.cpp
new file mode 100644
index 0000000..fe29b04
--- /dev/null
+++ b/Tests/CMakeCommands/target_compile_features/main.cpp
@@ -0,0 +1,6 @@
+
+int main(int, char **)
+{
+  auto i = 0;
+  return i;
+}