[libcxx-commits] [libcxx] [AIX][libc++] fopen() does not support the 'x' (exclusive/noreplace) mode suffix. (PR #206498)

[Nikolas Klauser via libcxx-commits]

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@@ -1206,9 +1220,19 @@ public:
   }
 #    endif
   [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool is_open() const;
-  void open(const char* __s, ios_base::openmode __mode = ios_base::in);
+  void open(const char* __s, ios_base::openmode __mode = ios_base::in)
+#    if defined(_AIX)
+      _LIBCPP_DIAGNOSE_WARNING(__mode& ios_base::noreplace,
+                               "fstream::open() with noreplace is not supported on AIX; open() will return failure")
+#    endif
+          ;
 #    if _LIBCPP_HAS_OPEN_WITH_WCHAR
-  void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in);
+  void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in)
+#      if defined(_AIX)
+      _LIBCPP_DIAGNOSE_WARNING(__mode& ios_base::noreplace,
+                               "fstream::open() with noreplace is not supported on AIX; open() will return failure")
+#      endif
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philnik777 wrote:

This change is probably garbage and definitely untested.

https://github.com/llvm/llvm-project/pull/206498