[libc++][AIX] Add AIX error message as expected output

[ZarkoCA]

Summary

AIX's libc generates "Error -1 occurred" instead of the "Unknown Error"
expected by these test cases. Add this as expected output for AIX only.

[zibi]

LGTM

[daltenty]

LGTM, just copying the longer rational why the message is expected on AIX.

Looks like it's looking for the fallback message text from do_strerror_r. Which is returned if handle_strerror_r_return generates no message, which it would if strerror_r returned error EINVAL.

According to POSIX for strerror_r:

These functions may fail if:

[EINVAL]
[CX] [Option Start] The value of errnum is neither a valid error number nor zero. [Option End]

That's a may, so I guess libc is ok to return it's own unknown error message string for unknown error codes which it does on AIX.

[• Quuxplusone]

libcxx/test/std/diagnostics/syserr/syserr.errcat/syserr.errcat.objects/system_category.pass.cpp

34

Seems reasonable to me, but please pull the preprocessor directives back to column 0:

#if defined(_AIX)
    LIBCPP_ASSERT(msg.rfind("Error -1 occurred", 0) == 0);
#else

etc.

libcxx/test/std/diagnostics/syserr/syserr.errcat/syserr.errcat.objects/generic_category.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // XFAIL: suse-linux-enterprise-server-11
 // XFAIL: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11|12}}
-// XFAIL: LIBCXX-AIX-FIXME
 
 // <system_error>
 
 // class error_category
 
 // const error_category& generic_category();
 
 #include <system_error>
 #include <cassert>
 #include <string>
 #include <cerrno>
 
 #include "test_macros.h"
 
 void test_message_for_bad_value() {
     errno = E2BIG; // something that message will never generate
     const std::error_category& e_cat1 = std::generic_category();
     const std::string msg = e_cat1.message(-1);
     // Exact message format varies by platform.
+    #if defined(_AIX)
+    LIBCPP_ASSERT(msg.rfind("Error -1 occurred", 0) == 0);
+    #else
     LIBCPP_ASSERT(msg.rfind("Unknown error", 0) == 0);
+    #endif
     assert(errno == E2BIG);
 }
 
 int main(int, char**)
 {
     const std::error_category& e_cat1 = std::generic_category();
     std::string m1 = e_cat1.name();
     assert(m1 == "generic");
     {
         test_message_for_bad_value();
     }
 
   return 0;
 }

libcxx/test/std/diagnostics/syserr/syserr.errcat/syserr.errcat.objects/system_category.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // <system_error>
 
 // class error_category
 
 // const error_category& system_category();
 
 // XFAIL: suse-linux-enterprise-server-11
 // XFAIL: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11|12}}
-// XFAIL: LIBCXX-AIX-FIXME
 
 #include <system_error>
 #include <cassert>
 #include <string>
 #include <cerrno>
 
 #include "test_macros.h"
 
 void test_message_for_bad_value() {
     errno = E2BIG; // something that message will never generate
     const std::error_category& e_cat1 = std::system_category();
     const std::string msg = e_cat1.message(-1);
     // Exact message format varies by platform.
+    #if defined(_AIX)
+    LIBCPP_ASSERT(msg.rfind("Error -1 occurred", 0) == 0);
+    #else
     LIBCPP_ASSERT(msg.rfind("Unknown error", 0) == 0);
+    #endif
     assert(errno == E2BIG);
 }
 
 int main(int, char**)
 {
     const std::error_category& e_cat1 = std::system_category();
     std::error_condition e_cond = e_cat1.default_error_condition(5);
     assert(e_cond.value() == 5);