Remove build options for conditionally enabling targets

* We don't have a use-case for this.

* Swift, like Clang, is fundamentally a cross-compiler, and there is no
  known reason to artificially limit it.

Author: gribozavr

CMakeLists.txt

@@ -54,10 +54,6 @@ option(SWIFT_INCLUDE_DOCS
     "Create targets for building docs."
     TRUE)
 
-option(SWIFT_ENABLE_TARGET_LINUX
-    "Enable compiler support for targeting Linux"
-    TRUE)
-
 set(SWIFT_VERSION "2.2" CACHE STRING
     "The user-visible version of the Swift compiler")
 set(SWIFT_VENDOR "" CACHE STRING

lib/Driver/CMakeLists.txt

@@ -17,9 +17,3 @@ add_swift_library(swiftDriver
   DEPENDS SwiftOptions
   LINK_LIBRARIES swiftAST swiftBasic swiftFrontend swiftOption)
 
-if(${SWIFT_ENABLE_TARGET_LINUX})
-  foreach(f ${swiftDriver_sources})
-    set_property(SOURCE ${f} APPEND_STRING PROPERTY COMPILE_FLAGS
-        " -DSWIFT_ENABLE_TARGET_LINUX=\"1\"")
-  endforeach()
-endif()

lib/Driver/Driver.cpp

@@ -2035,11 +2035,9 @@ const ToolChain *Driver::getToolChain(const ArgList &Args) const {
     case llvm::Triple::WatchOS:
       TC = new toolchains::Darwin(*this, Target);
       break;
-#if defined(SWIFT_ENABLE_TARGET_LINUX)
     case llvm::Triple::Linux:
       TC = new toolchains::Linux(*this, Target);
       break;
-#endif // SWIFT_ENABLE_TARGET_LINUX
     default:
       TC = nullptr;
     }

lib/Driver/ToolChains.cpp

@@ -998,8 +998,6 @@ toolchains::Darwin::constructInvocation(const LinkJobAction &job,
   return {"ld", Arguments};
 }
 
-#if defined(SWIFT_ENABLE_TARGET_LINUX)
-
 ToolChain::InvocationInfo
 toolchains::Linux::constructInvocation(const InterpretJobAction &job,
                                        const JobContext &context) const {
@@ -1127,5 +1125,3 @@ toolchains::Linux::constructInvocation(const LinkJobAction &job,
   return {"clang++", Arguments};
 }
 
-#endif // SWIFT_ENABLE_TARGET_LINUX
-

lib/Driver/ToolChains.h

@@ -36,8 +36,6 @@ class LLVM_LIBRARY_VISIBILITY Darwin : public ToolChain {
 
 };
 
-#if defined(SWIFT_ENABLE_TARGET_LINUX)
-
 class LLVM_LIBRARY_VISIBILITY Linux : public ToolChain {
 protected:
   InvocationInfo constructInvocation(const InterpretJobAction &job,
@@ -52,8 +50,6 @@ class LLVM_LIBRARY_VISIBILITY Linux : public ToolChain {
   ~Linux() = default;
 };
 
-#endif // SWIFT_ENABLE_TARGET_LINUX
-
 } // end namespace toolchains
 } // end namespace driver
 } // end namespace swift

utils/build-script-impl

@@ -170,8 +170,6 @@ KNOWN_SETTINGS=(
     extra-swift-args            ""               "Extra arguments to pass to swift modules which match regex. Assumed to be a flattened cmake list consisting of [module_regexp, args, module_regexp, args, ...]"
     sil-verify-all              "0"              "If enabled, run the sil verifier be run after every SIL pass"
     swift-enable-ast-verifier   "1"              "If enabled, and the assertions are enabled, the built Swift compiler will run the AST verifier every time it is invoked"
-    swift-enable-target-linux   "1"              "Enable compiler support for targeting Linux"
-    swift-enable-target-freebsd "1"              "Enable compiler support for targeting FreeBSD"
     swift-runtime-enable-dtrace "0"              "Enable runtime dtrace support"
     swift-runtime-enable-leak-checker   "0"              "Enable leaks checking routines in the runtime"
     use-gold-linker             ""               "Enable using the gold linker"
@@ -1425,7 +1423,6 @@ for deployment_target in "${NATIVE_TOOLS_DEPLOYMENT_TARGETS[@]}" "${CROSS_TOOLS_
         -DSWIFT_VERIFY_ALL:BOOL=$(true_false "${SIL_VERIFY_ALL}")
         -DSWIFT_RUNTIME_ENABLE_DTRACE:BOOL=$(true_false "${SWIFT_RUNTIME_ENABLE_DTRACE}")
         -DSWIFT_RUNTIME_ENABLE_LEAK_CHECKER:BOOL=$(true_false "${SWIFT_RUNTIME_ENABLE_LEAK_CHECKER}")
-        -DSWIFT_ENABLE_TARGET_LINUX:BOOL=$(true_false "${SWIFT_ENABLE_TARGET_LINUX}")
     )
 
     for product in "${PRODUCTS[@]}"; do