CMake: SwiftCore: Add back SWIFT_STDLIB_SUPPORTS_BACKTRACE_REPORTING

Add an option to enable emitting a stacktrace on calls to `fatalError`.
This is unrelated to the runtime backtracer for diagnosing normal Swift
crashes.

rdar://142440689

Author: etcwilde

Runtimes/Core/CMakeLists.txt

@@ -103,6 +103,7 @@ option(SwiftCore_ENABLE_FILESYSTEM_SUPPORT "Build for systems that have a filesy
 
 defaulted_option(SwiftCore_ENABLE_BACKTRACING "Enable backtracing runtime support")
 defaulted_set(SwiftCore_BACKTRACER_PATH STRING "Set a fixed path to the Swift backtracer")
+defaulted_option(SwiftCore_ENABLE_FATALERROR_BACKTRACE "Build stdlib fatalError with backtrace output")
 
 option(SwiftCore_ENABLE_CLOBBER_FREED_OBJECTS "" OFF)
 option(SwiftCore_ENABLE_RUNTIME_LEAK_CHECKER "" OFF)

Runtimes/Core/cmake/modules/DefaultSettings.cmake

@@ -37,6 +37,7 @@ if(APPLE)
   set(SwiftCore_ENABLE_CRASH_REPORTER_CLIENT_default ON)
   set(SwiftCore_ENABLE_OBJC_INTEROP_default ON)
   set(SwiftCore_ENABLE_REFLECTION_default ON)
+  set(SwiftCore_ENABLE_FATALERROR_BACKTRACE_default ON)
   set(SwiftCore_ENABLE_RUNTIME_OS_VERSIONING ON)
   set(SwiftCore_ENABLE_OVERRIDABLE_RETAIN_RELEASE ON)
   set(SwiftCore_THREADING_PACKAGE "DARWIN")
@@ -45,6 +46,7 @@ elseif(CMAKE_SYSTEM_NAME STREQUAL "WASM")
   set(SwiftCore_THREADING_PACKAGE "NONE")
 elseif(LINUX OR ANDROID OR BSD)
   set(SwiftCore_OBJECT_FORMAT_default "elf")
+  set(SwiftCore_ENABLE_FATALERROR_BACKTRACE_default ON)
   if(LINUX)
     set(SwiftCore_THREADING_PACKAGE "LINUX")
   else()
@@ -53,6 +55,7 @@ elseif(LINUX OR ANDROID OR BSD)
 elseif(WIN32)
   set(SwiftCore_OBJECT_FORMAT_default "coff")
   set(SwiftCore_THREADING_PACKAGE "WIN32")
+  set(SwiftCore_ENABLE_FATALERROR_BACKTRACE_default ON)
 endif()
 
 include("${SwiftCore_VENDOR_MODULE_DIR}/DefaultSettings.cmake" OPTIONAL)

Runtimes/Core/runtime/CMakeLists.txt

@@ -100,7 +100,8 @@ target_compile_definitions(swiftRuntime
     $<$<BOOL:${SwiftCore_HAS_DLSYM}>:-DSWIFT_STDLIB_HAS_DLSYM>
     $<$<BOOL:${SwiftCore_ENABLE_FILESYSTEM_SUPPORT}>:-DSWIFT_STDLIB_HAS_FILESYSTEM>
     $<$<BOOL:${SwiftCore_ENABLE_FILESYSTEM_SUPPORT}>:-DSWIFT_ARCH="${SwiftCore_ARCH_SUBDIR}">
-    $<$<BOOL:${SwiftCore_ENABLE_FILESYSTEM_SUPPORT}>:-DSWIFT_LIB_SUBDIR="${SwiftCore_PLATFORM_SUBDIR}">)
+    $<$<BOOL:${SwiftCore_ENABLE_FILESYSTEM_SUPPORT}>:-DSWIFT_LIB_SUBDIR="${SwiftCore_PLATFORM_SUBDIR}">
+    $<$<BOOL:${SwiftCore_ENABLE_FATALERROR_BACKTRACE}>:-DSWIFT_STDLIB_SUPPORTS_BACKTRACE_REPORTING>)
 
 target_include_directories(swiftRuntime PRIVATE
   "${PROJECT_BINARY_DIR}/include"