[libcxx] [test] Remove non-portable assertions from filebuf tests

[BillyONeal]

Summary

seekoff.pass.cpp:

libc++'s tests are asserting things about the buffer passed to pubsetbuf. [filebuf.virtuals]/12 says that what the filebuf does with the buffer you give it is completely implementation defined. The MSVC++ implementation takes that buffer and hands it off to the CRT (by calling ::setvbuf) and the CRT doesn't necessarily follow the pattern this test wants.

This change simply makes asserts against the buffer's contents use LIBCPP_ASSERT instead of assert.

pbackfail.pass.cpp:
libc++'s tests are asserting about what characters will and will not be available in the putback area. [filebuf.virtuals]/9 says "The function can alter the number of putback positions available as a result of any call." This change LIBCPP_ASSERTS libc++'s behavior, but checks invariants of the putback area independently.

[BillyONeal]

Added pbackfail.pass.cpp changes.

[BillyONeal]

@mclow.lists Are you OK with this one? It's conceptually similar to the previous review.

[mclow.lists]

This looks OK to me.

[BillyONeal]

D:\msvc\src\qa\VC\Libs\libcxx\upstream>git svn dcommit
Committing to https://llvm.org/svn/llvm-project/libcxx/trunk ...
Use of uninitialized value $rec in scalar chomp at /mingw64/share/perl5/Git.pm line 557, <$fh> chunk 4.
Authentication realm: https://llvm.org:443 LLVM Subversion repository
Password for 'bion':

M       test/std/input.output/file.streams/fstreams/filebuf.virtuals/pbackfail.pass.cpp
M       test/std/input.output/file.streams/fstreams/filebuf.virtuals/seekoff.pass.cpp

Committed r330999

M       test/std/input.output/file.streams/fstreams/filebuf.virtuals/pbackfail.pass.cpp
M       test/std/input.output/file.streams/fstreams/filebuf.virtuals/seekoff.pass.cpp

r330999 = dc3bb72e3c9a47ef62d6288f73d164d3ba5fe941 (refs/remotes/llvm/master)
No changes between 706a727f5b068a7b5c6f43028cdbaf6ea610abe6 and refs/remotes/llvm/master
Resetting to the latest refs/remotes/llvm/master

D:\msvc\src\qa\VC\Libs\libcxx\upstream>

test/std/input.output/file.streams/fstreams/filebuf.virtuals/pbackfail.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 // <fstream>
 
 // int_type pbackfail(int_type c = traits::eof());
 
-// This test is not entirely portable
-
 #include <fstream>
 #include <cassert>
 
+#include "test_macros.h"
+
 template <class CharT>
 struct test_buf
     : public std::basic_filebuf<CharT>
 {
     typedef std::basic_filebuf<CharT>  base;
     typedef typename base::char_type   char_type;
     typedef typename base::int_type    int_type;
     typedef typename base::traits_type traits_type;

 int main()
 {
     {
         test_buf<char> f;
         assert(f.open("underflow.dat", std::ios_base::in) != 0);
         assert(f.is_open());
         assert(f.sbumpc() == '1');
         assert(f.sgetc() == '2');
-        assert(f.pbackfail('a') == -1);
+        typename test_buf<char>::int_type pbackResult = f.pbackfail('a');
+        LIBCPP_ASSERT(pbackResult == -1);
+        if (pbackResult != -1) {
+            assert(f.sbumpc() == 'a');
+            assert(f.sgetc() == '2');
+        }
     }
     {
         test_buf<char> f;
         assert(f.open("underflow.dat", std::ios_base::in | std::ios_base::out) != 0);
         assert(f.is_open());
         assert(f.sbumpc() == '1');
         assert(f.sgetc() == '2');
-        assert(f.pbackfail('a') == 'a');
+        typename test_buf<char>::int_type pbackResult = f.pbackfail('a');
+        LIBCPP_ASSERT(pbackResult == 'a');
+        if (pbackResult != -1) {
             assert(f.sbumpc() == 'a');
             assert(f.sgetc() == '2');
         }
     }
+}

test/std/input.output/file.streams/fstreams/filebuf.virtuals/seekoff.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 // <fstream>
 
 // pos_type seekoff(off_type off, ios_base::seekdir way,
 //                  ios_base::openmode which = ios_base::in | ios_base::out);
 // pos_type seekpos(pos_type sp,
 //                  ios_base::openmode which = ios_base::in | ios_base::out);
 
-// This test is not entirely portable
-
 #include <fstream>
 #include <cassert>
 
+#include "test_macros.h"
+
 int main()
 {
     {
         char buf[10];
         typedef std::filebuf::pos_type pos_type;
         std::filebuf f;
         f.pubsetbuf(buf, sizeof(buf));
         assert(f.open("seekoff.dat", std::ios_base::in | std::ios_base::out
                                                        | std::ios_base::trunc) != 0);
         assert(f.is_open());
         f.sputn("abcdefghijklmnopqrstuvwxyz", 26);
-        assert(buf[0] == 'v');
+        LIBCPP_ASSERT(buf[0] == 'v');
         pos_type p = f.pubseekoff(-15, std::ios_base::cur);
         assert(p == 11);
         assert(f.sgetc() == 'l');
         f.pubseekoff(0, std::ios_base::beg);
         assert(f.sgetc() == 'a');
         f.pubseekoff(-1, std::ios_base::end);
         assert(f.sgetc() == 'z');
         assert(f.pubseekpos(p) == p);
         assert(f.sgetc() == 'l');
     }
     std::remove("seekoff.dat");
     {
         wchar_t buf[10];
         typedef std::filebuf::pos_type pos_type;
         std::wfilebuf f;
         f.pubsetbuf(buf, sizeof(buf)/sizeof(buf[0]));
         assert(f.open("seekoff.dat", std::ios_base::in | std::ios_base::out
                                                        | std::ios_base::trunc) != 0);
         assert(f.is_open());
         f.sputn(L"abcdefghijklmnopqrstuvwxyz", 26);
-        assert(buf[0] == L'v');
+        LIBCPP_ASSERT(buf[0] == L'v');
         pos_type p = f.pubseekoff(-15, std::ios_base::cur);
         assert(p == 11);
         assert(f.sgetc() == L'l');
         f.pubseekoff(0, std::ios_base::beg);
         assert(f.sgetc() == L'a');
         f.pubseekoff(-1, std::ios_base::end);
         assert(f.sgetc() == L'z');
         assert(f.pubseekpos(p) == p);
         assert(f.sgetc() == L'l');
     }
     std::remove("seekoff.dat");
 }