Setup reasonable defaults

This patch makes it simpler to setup reasonable defaults for a given
platform. The standard library has many knobs for configuration
purposes. This is great for providing cache files to configure specific
builds, but the build system should still generally work if someone runs
a minimal CMake invocation against the build without futzing with
various options.

Author: etcwilde

Runtimes/Core/CMakeLists.txt

@@ -55,23 +55,22 @@ include(EmitSwiftInterface)
 include(PlatformInfo)
 include(gyb)
 
-option(SwiftCore_ENABLE_LIBRARY_EVOLUTION "Generate ABI resilient runtime libraries" OFF)
+defaulted_option(SwiftCore_ENABLE_LIBRARY_EVOLUTION "Generate ABI resilient runtime libraries")
 
-option(SwiftCore_ENABLE_CRASH_REPORTER_CLIENT "Enable Apple CrashReporter integration" OFF)
-option(SwiftCore_ENABLE_OBJC_INTEROP "Enable runtime ObjC interop" OFF)
-option(SwiftCore_ENABLE_TYPE_PRINTING "Enable printing type names" OFF)
-option(SwiftCore_ENABLE_VECTOR_TYPES "Enable vector support" OFF)
+defaulted_option(SwiftCore_ENABLE_CRASH_REPORTER_CLIENT "Enable Apple CrashReporter integration")
+defaulted_option(SwiftCore_ENABLE_OBJC_INTEROP "Enable runtime ObjC interop")
+defaulted_option(SwiftCore_ENABLE_TYPE_PRINTING "Enable printing type names")
+defaulted_option(SwiftCore_ENABLE_VECTOR_TYPES "Enable vector support")
+defaulted_option(SwiftCore_ENABLE_REFLECTION "Enable runtime support for mirrors and reflection support")
+defaulted_option(SwiftCore_ENABLE_COMMANDLINE_SUPPORT "Enable command line argument support")
 
-option(SwiftCore_ENABLE_CLOBBER_FREED_OBJECTS "" ${SwiftCore_ENABLE_CLOBBER_FREED_OBJECTS_default})
-option(SwiftCore_ENABLE_RUNTIME_LEAK_CHECKER "" ${SwiftCore_ENABLE_RIUNTIME_LEAK_CHECKER_default})
-option(SwiftCore_ENABLE_REFLECTION "" OFF)
+defaulted_option(SwiftCore_ENABLE_BACKTRACING "Enable backtracing runtime support")
+set(SwiftCore_BACKTRACER_PATH ${SwiftCore_BACKTRACER_PATH_default} CACHE STRING "Set a fixed path to the Swift backtracer")
 
-option(SwiftCore_ENABLE_COMMANDLINE_SUPPORT "Enable command line argument support" OFF)
+option(SwiftCore_ENABLE_CLOBBER_FREED_OBJECTS "" OFF)
+option(SwiftCore_ENABLE_RUNTIME_LEAK_CHECKER "" OFF)
 
-option(SwiftCore_ENABLE_BACKTRACING "Enable backtracing runtime support" OFF)
-set(SwiftCore_BACKTRACER_PATH "" CACHE STRING "Set a fixed path to the Swift backtracer")
-
-set(SwiftCore_OBJECT_FORMAT ${SwiftCore_OBJECT_FORMAT} CACHE STRING "Object format")
+set(SwiftCore_OBJECT_FORMAT "${SwiftCore_OBJECT_FORMAT_default}" CACHE STRING "Object format")
 
 add_compile_definitions(
   $<$<COMPILE_LANGUAGE:C,CXX>:-DSWIFT_OBJC_INTEROP=$<BOOL:${SwiftCore_ENABLE_OBJC_INTEROP}>>

Runtimes/Core/cmake/modules/DefaultSettings.cmake

@@ -4,15 +4,25 @@
 # way that will work. The config files under `cmake/configs` are build
 # configurations that are actually shipping.
 
-set(SwiftCore_ENABLE_CRASH_REPORTER_CLIENT_default OFF)
-set(SwiftCore_ENABLE_OBJC_INTEROP_default OFF)
+set(SwiftCore_ENABLE_BACKTRACING_default OFF) # TODO: enable this by default
+set(SwiftCore_ENABLE_COMMANDLINE_SUPPORT_default OFF) # TODO: enable this by default
+
 set(SwiftCore_ENABLE_TYPE_PRINTING_default ON)
-set(SwiftCore_ENABLE_CLOBBER_FREED_OBJECTS_default OFF)
-set(SwiftCore_ENABLE_BACKTRACING_default OFF)
+
 set(SwiftCore_BACKTRACER_PATH_default "")
 
+macro(defaulted_option variable helptext)
+  if(NOT DEFINED ${variable}_default)
+    set(${variable}_default OFF)
+  endif()
+  option(${variable} ${helptext} ${${variable}_default})
+endmacro()
+
 if(APPLE)
+  set(SwiftCore_ENABLE_LIBRARY_EVOLUTION_default ON)
   set(SwiftCore_ENABLE_CRASH_REPORTER_CLIENT_default ON)
+  set(SwiftCore_ENABLE_OBJC_INTEROP_default ON)
+  set(SwiftCore_ENABLE_REFLECTION_default ON)
 elseif(CMAKE_SYSTEM_NAME STREQUAL "WASM")
   set(SwiftCore_OBJECT_FORMAT_default "elf")
 elseif(LINUX)