Merge pull request #42279 from eeckstein/fix-hosttools-mode

Fix the 'hosttools' bootstrapping build mode

Author: eeckstein

SwiftCompilerSources/CMakeLists.txt

@@ -74,7 +74,7 @@ function(add_swift_compiler_modules_library name)
 
   set(swift_compile_options
       "-Xfrontend" "-validate-tbd-against-ir=none"
-      "-Xfrontend" "-enable-experimental-cxx-interop"
+      "-Xfrontend" "-enable-cxx-interop"
       "-Xcc" "-UIBOutlet" "-Xcc" "-UIBAction" "-Xcc" "-UIBInspectable")
 
   if(CMAKE_BUILD_TYPE STREQUAL Debug)

include/swift/Option/FrontendOptions.td

@@ -828,6 +828,11 @@ def enable_experimental_cxx_interop :
   HelpText<"Enable C++ interop code generation and config directives">,
   Flags<[FrontendOption, HelpHidden]>;
 
+def enable_cxx_interop :
+  Flag<["-"], "enable-cxx-interop">,
+  HelpText<"Alias for -enable-experimental-cxx-interop">,
+  Flags<[FrontendOption, HelpHidden]>;
+
 def use_malloc : Flag<["-"], "use-malloc">,
   HelpText<"Allocate internal data structures using malloc "
            "(for memory debugging)">;

lib/Frontend/CompilerInvocation.cpp

@@ -757,7 +757,8 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
     Opts.ClangTarget = llvm::Triple(A->getValue());
   }
 
-  Opts.EnableCXXInterop |= Args.hasArg(OPT_enable_experimental_cxx_interop);
+  Opts.EnableCXXInterop |= Args.hasArg(OPT_enable_experimental_cxx_interop) |
+                           Args.hasArg(OPT_enable_cxx_interop);
   Opts.EnableObjCInterop =
       Args.hasFlag(OPT_enable_objc_interop, OPT_disable_objc_interop,
                    Target.isOSDarwin());