[libc++] Add configuration define for off_t functions

Create this define in __config and use it elsewhere, instead of checking
the operating system/library defines in other files. The aim is to
reduce the usage of _WIN32 outside __config. No functional change.

Differential Revision: https://reviews.llvm.org/D25741

llvm-svn: 285582

diff --git a/libcxx/include/__config b/libcxx/include/__config
index 572b015..cd8c2aa 100644 (file)
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -904,6 +904,12 @@ extern "C" void __sanitizer_annotate_contiguous_container(
 #define _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
 #endif
 
+#if !defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
+#if defined(_WIN32) || defined(_NEWLIB_VERSION)
+#define _LIBCPP_HAS_NO_OFF_T_FUNCTIONS
+#endif
+#endif
+
 #endif // __cplusplus
 
 #endif // _LIBCPP_CONFIG

diff --git a/libcxx/include/fstream b/libcxx/include/fstream
index ce13b31..b8d18aa 100644 (file)
--- a/libcxx/include/fstream
+++ b/libcxx/include/fstream
@@ -813,7 +813,7 @@ basic_filebuf<_CharT, _Traits>::seekoff(off_type __off, ios_base::seekdir __way,
     default:
         return pos_type(off_type(-1));
     }
-#if defined(_WIN32) || defined(_NEWLIB_VERSION)
+#if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
     if (fseek(__file_, __width > 0 ? __width * __off : 0, __whence))
         return pos_type(off_type(-1));
     pos_type __r = ftell(__file_);
@@ -832,7 +832,7 @@ basic_filebuf<_CharT, _Traits>::seekpos(pos_type __sp, ios_base::openmode)
 {
     if (__file_ == 0 || sync())
         return pos_type(off_type(-1));
-#if defined(_WIN32) || defined(_NEWLIB_VERSION)
+#if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
     if (fseek(__file_, __sp, SEEK_SET))
         return pos_type(off_type(-1));
 #else
@@ -896,7 +896,7 @@ basic_filebuf<_CharT, _Traits>::sync()
                 }
             }
         }
-#if defined(_WIN32) || defined(_NEWLIB_VERSION)
+#if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
         if (fseek(__file_, -__c, SEEK_CUR))
             return -1;
 #else