Remove a long-standing __has_include hack.

This was put in to get libc++ building without libcxxabi. We now have
macros that show that we are building against libcxxabi so use that
instead. This guards against existing but broken cxxabi.h headers on the
system.

llvm-svn: 250507

libcxx/src/exception.cpp

@@ -12,10 +12,6 @@
 #include "exception"
 #include "new"
 
-#ifndef __has_include
-#define __has_include(inc) 0
-#endif
-
 #if defined(__APPLE__) && !defined(LIBCXXRT)
   #include <cxxabi.h>
 
@@ -29,16 +25,16 @@
     #define __terminate_handler  __cxxabiapple::__cxa_terminate_handler
     #define __unexpected_handler __cxxabiapple::__cxa_unexpected_handler
   #endif  // _LIBCPPABI_VERSION
-#elif defined(LIBCXXRT) || defined(LIBCXX_BUILDING_LIBCXXABI) || __has_include(<cxxabi.h>)
+#elif defined(LIBCXXRT) || defined(LIBCXX_BUILDING_LIBCXXABI)
   #include <cxxabi.h>
   using namespace __cxxabiv1;
   #if defined(LIBCXXRT) || defined(_LIBCPPABI_VERSION)
     #define HAVE_DEPENDENT_EH_ABI 1
   #endif
-#elif !defined(__GLIBCXX__) // __has_include(<cxxabi.h>)
+#elif !defined(__GLIBCXX__) // defined(LIBCXX_BUILDING_LIBCXXABI)
   static std::terminate_handler  __terminate_handler;
   static std::unexpected_handler __unexpected_handler;
-#endif // __has_include(<cxxabi.h>)
+#endif // defined(LIBCXX_BUILDING_LIBCXXABI)
 
 namespace std
 {

libcxx/src/new.cpp

@@ -13,10 +13,6 @@
 
 #include "new"
 
-#ifndef __has_include
-#define __has_include(inc) 0
-#endif
-
 #if defined(__APPLE__) && !defined(LIBCXXRT)
     #include <cxxabi.h>
 
@@ -27,9 +23,9 @@
         #define __new_handler __cxxabiapple::__cxa_new_handler
     #endif
 #else  // __APPLE__
-    #if defined(LIBCXXRT) || __has_include(<cxxabi.h>)
+    #if defined(LIBCXXRT) || defined(LIBCXX_BUILDING_LIBCXXABI)
         #include <cxxabi.h>
-    #endif  // __has_include(<cxxabi.h>)
+    #endif  // defined(LIBCXX_BUILDING_LIBCXXABI)
     #if !defined(_LIBCPPABI_VERSION) && !defined(__GLIBCXX__)
         static std::new_handler __new_handler;
     #endif  // _LIBCPPABI_VERSION

libcxx/src/stdexcept.cpp

@@ -13,12 +13,8 @@
 #include "string"
 #include "system_error"
 
-#ifndef __has_include
-#define __has_include(inc) 0
-#endif
-
 /* For _LIBCPPABI_VERSION */
-#if __has_include(<cxxabi.h>) || defined(__APPLE_) || defined(LIBCXXRT)
+#if defined(LIBCXX_BUILDING_LIBCXXABI) || defined(__APPLE_) || defined(LIBCXXRT)
 #include <cxxabi.h>
 #endif
 

libcxx/src/typeinfo.cpp

@@ -8,13 +8,8 @@
 //===----------------------------------------------------------------------===//
 #include <stdlib.h>
 
-#ifndef __has_include
-#define __has_include(inc) 0
-#endif
-
-#ifdef __APPLE__
-#include <cxxabi.h>
-#elif defined(LIBCXXRT) || __has_include(<cxxabi.h>)
+#if defined(__APPLE__) || defined(LIBCXXRT) ||                                 \
+    defined(LIBCXX_BUILDING_LIBCXXABI)
 #include <cxxabi.h>
 #endif