Files
clang-p2996/libcxx/test/std/input.output/syncstream/syncbuf/syncstream.syncbuf.assign/swap.pass.cpp
Stephan T. Lavavej b2cc4b994e [libc++][test] Fix more MSVC and Clang warnings (#74965)
Found while running libc++'s tests with MSVC's STL.

*
`libcxx/test/std/algorithms/alg.sorting/alg.heap.operations/sort.heap/ranges_sort_heap.pass.cpp`
+ Fix Clang `-Wunused-variable`, because `LIBCPP_ASSERT` expands to
nothing for MSVC's STL.
+ This is the same "always void-cast" change that #73437 applied to the
neighboring `complexity.pass.cpp`. I missed that
`ranges_sort_heap.pass.cpp` was also affected because we had disabled
this test.
*
`libcxx/test/std/input.output/file.streams/fstreams/ifstream.members/buffered_reads.pass.cpp`
*
`libcxx/test/std/input.output/file.streams/fstreams/ofstream.members/buffered_writes.pass.cpp`
+ Fix MSVC "warning C4244: '`=`': conversion from '`__int64`' to
'`_Ty`', possible loss of data".
+ This is a valid warning, possibly the best one that MSVC found in this
entire saga. We're accumulating a `std::vector<std::streamsize>` and
storing the result in `std::streamsize total_size` but we actually have
to start with `std::streamsize{0}` or we'll truncate.
*
`libcxx/test/std/input.output/filesystems/fs.enum/enum.path.format.pass.cpp`
+ Fix Clang `-Wunused-local-typedef` because the following usage is
libc++-only.
+ I'm just expanding it at the point of use, and using the dedicated
`LIBCPP_STATIC_ASSERT` to keep the line length down.
*
`libcxx/test/std/input.output/syncstream/syncbuf/syncstream.syncbuf.assign/swap.pass.cpp`
+ Fix MSVC "warning C4242: 'argument': conversion from '`int`' to
'`const _Elem`', possible loss of data".
+ This is a valid warning (possibly the second-best) as `sputc()`
returns `int_type`. If `sputc()` returns something unexpected, we want
to know, so we should separately say `expected.push_back(CharT('B'))`.
*
`libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new.size_align_nothrow.pass.cpp`
*
`libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new.size_nothrow.pass.cpp`
  + Fix MSVC "warning C6001: Using uninitialized memory '`x`'."
  + [N4964](https://wg21.link/N4964) \[new.delete.single\]/12:
> *Effects:* The deallocation functions
(\[basic.stc.dynamic.deallocation\]) called by a *delete-expression*
(\[expr.delete\]) to render the value of `ptr` invalid.
  + \[basic.stc.general\]/4:
> When the end of the duration of a region of storage is reached, the
values of all pointers representing the address of any part of that
region of storage become invalid pointer values (\[basic.compound\]).
Indirection through an invalid pointer value and passing an invalid
pointer value to a deallocation function have undefined behavior. Any
other use of an invalid pointer value has implementation-defined
behavior.
+ In certain configurations, after `delete x;` MSVC will consider `x` to
be radioactive (and in other configurations, it'll physically null out
`x` as a safety measure). We can copy it into `old_x` before deletion,
which the implementation finds acceptable.
*
`libcxx/test/std/ranges/range.adaptors/range.elements/general.pass.cpp`
*
`libcxx/test/std/ranges/range.adaptors/range.elements/iterator/deref.pass.cpp`
+ Fix MSVC "warning C4242: 'initializing': conversion from '`_Ty`' to
'`_Ty`', possible loss of data".
+ This was being emitted in `pair` and `tuple`'s perfect forwarding
constructors. Passing `short{1}` allows MSVC to see that no truncation
is happening.
*
`libcxx/test/std/ranges/range.adaptors/range.elements/iterator/member_types.compile.pass.cpp`
+ Fix MSVC "warning C4242: 'initializing': conversion from '`_Ty`' to
'`_Ty2`', possible loss of data".
+ Similarly, this was being emitted in `pair`'s perfect forwarding
constructor. After passing `short{1}`, I reduced repetition by relying
on CTAD. (I can undo that cleanup if it's stylistically undesirable.)
*
`libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor.pass.cpp`
+ Fix MSVC "warning C4930: '`std::reference_wrapper<int> purr(void)`':
prototyped function not called (was a variable definition intended?)".
+ There's no reason for `purr()` to be locally declared (aside from
isolating it to a narrow scope, which has minimal benefits); it can be
declared like `meow()` above. 😸
*
`libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared_for_overwrite.pass.cpp`
*
`libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.create/make_unique_for_overwrite.default_init.pass.cpp`
  + Fix MSVC static analysis warnings when replacing `operator new`:
    ```
warning C28196: The requirement that '(_Param_(1)>0)?(return!=0):(1)' is
not satisfied. (The expression does not evaluate to true.)
warning C6387: 'return' could be '0': this does not adhere to the
specification for the function 'new'.
warning C6011: Dereferencing NULL pointer 'reinterpret_cast<char
*>ptr+i'.
    ```
+ All we need is a null check, which appears in other `operator new`
replacements:
b85f1f9b18/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new.size.replace.pass.cpp (L27-L28)
2023-12-10 13:46:40 -08:00

276 lines
7.4 KiB
C++

//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// UNSUPPORTED: no-localization
// UNSUPPORTED: libcpp-has-no-experimental-syncstream
// <syncstream>
// template <class charT, class traits, class Allocator>
// class basic_syncbuf;
// void swap(basic_syncbuf& other) noexcept;
#include <syncstream>
#include <sstream>
#include <cassert>
#include "test_macros.h"
#include <iostream>
template <class CharT>
static void test_basic() {
std::basic_stringbuf<CharT> sstr1;
std::basic_stringbuf<CharT> sstr2;
std::basic_string<CharT> expected(42, CharT('*')); // a long string
{
std::basic_syncbuf<CharT> sync_buf1(&sstr1);
sync_buf1.sputc(CharT('A')); // a short string
std::basic_syncbuf<CharT> sync_buf2(&sstr2);
sync_buf2.sputn(expected.data(), expected.size());
#if defined(_LIBCPP_VERSION) && !defined(TEST_HAS_NO_THREADS)
assert(std::__wrapped_streambuf_mutex::__instance().__get_count(&sstr1) == 1);
assert(std::__wrapped_streambuf_mutex::__instance().__get_count(&sstr2) == 1);
#endif
sync_buf1.swap(sync_buf2);
assert(sync_buf1.get_wrapped() == &sstr2);
assert(sync_buf2.get_wrapped() == &sstr1);
assert(sstr1.str().empty());
assert(sstr2.str().empty());
#if defined(_LIBCPP_VERSION) && !defined(TEST_HAS_NO_THREADS)
assert(std::__wrapped_streambuf_mutex::__instance().__get_count(&sstr1) == 1);
assert(std::__wrapped_streambuf_mutex::__instance().__get_count(&sstr2) == 1);
#endif
}
assert(sstr1.str().size() == 1);
assert(sstr1.str()[0] == CharT('A'));
assert(sstr2.str() == expected);
}
template <class CharT>
static void test_short_write_after_swap() {
std::basic_stringbuf<CharT> sstr1;
std::basic_stringbuf<CharT> sstr2;
std::basic_string<CharT> expected(42, CharT('*')); // a long string
{
std::basic_syncbuf<CharT> sync_buf1(&sstr1);
sync_buf1.sputc(CharT('A')); // a short string
std::basic_syncbuf<CharT> sync_buf2(&sstr2);
sync_buf2.sputn(expected.data(), expected.size());
sync_buf1.swap(sync_buf2);
sync_buf1.sputc(CharT('B'));
expected.push_back(CharT('B'));
sync_buf2.sputc(CharT('Z'));
assert(sstr1.str().empty());
assert(sstr2.str().empty());
}
assert(sstr1.str().size() == 2);
assert(sstr1.str()[0] == CharT('A'));
assert(sstr1.str()[1] == CharT('Z'));
assert(sstr2.str() == expected);
}
template <class CharT>
static void test_long_write_after_swap() {
std::basic_stringbuf<CharT> sstr1;
std::basic_stringbuf<CharT> sstr2;
std::basic_string<CharT> expected(42, CharT('*')); // a long string
{
std::basic_syncbuf<CharT> sync_buf1(&sstr1);
sync_buf1.sputc(CharT('A')); // a short string
std::basic_syncbuf<CharT> sync_buf2(&sstr2);
sync_buf2.sputn(expected.data(), expected.size());
sync_buf1.swap(sync_buf2);
sync_buf1.sputn(expected.data(), expected.size());
sync_buf2.sputn(expected.data(), expected.size());
assert(sstr1.str().empty());
assert(sstr2.str().empty());
}
assert(sstr1.str().size() == 1 + expected.size());
assert(sstr1.str()[0] == CharT('A'));
assert(sstr1.str().substr(1) == expected);
assert(sstr2.str() == expected + expected);
}
template <class CharT>
static void test_emit_on_sync() {
{ // false false
std::basic_stringbuf<CharT> sstr1;
std::basic_stringbuf<CharT> sstr2;
std::basic_string<CharT> expected(42, CharT('*')); // a long string
{
std::basic_syncbuf<CharT> sync_buf1(&sstr1);
sync_buf1.set_emit_on_sync(false);
sync_buf1.sputc(CharT('A')); // a short string
std::basic_syncbuf<CharT> sync_buf2(&sstr2);
sync_buf2.set_emit_on_sync(false);
sync_buf2.sputn(expected.data(), expected.size());
sync_buf1.swap(sync_buf2);
assert(sstr1.str().empty());
assert(sstr2.str().empty());
sync_buf1.pubsync();
assert(sstr1.str().empty());
assert(sstr2.str().empty());
sync_buf2.pubsync();
assert(sstr1.str().empty());
assert(sstr2.str().empty());
}
assert(sstr1.str().size() == 1);
assert(sstr1.str()[0] == CharT('A'));
assert(sstr2.str() == expected);
}
{ // false true
std::basic_stringbuf<CharT> sstr1;
std::basic_stringbuf<CharT> sstr2;
std::basic_string<CharT> expected(42, CharT('*')); // a long string
{
std::basic_syncbuf<CharT> sync_buf1(&sstr1);
sync_buf1.set_emit_on_sync(true);
sync_buf1.sputc(CharT('A')); // a short string
std::basic_syncbuf<CharT> sync_buf2(&sstr2);
sync_buf2.set_emit_on_sync(false);
sync_buf2.sputn(expected.data(), expected.size());
sync_buf1.swap(sync_buf2);
assert(sstr1.str().empty());
assert(sstr2.str().empty());
sync_buf1.pubsync();
assert(sstr1.str().empty());
assert(sstr2.str().empty());
sync_buf2.pubsync();
assert(sstr1.str().size() == 1);
assert(sstr1.str()[0] == CharT('A'));
assert(sstr2.str().empty());
}
assert(sstr1.str().size() == 1);
assert(sstr1.str()[0] == CharT('A'));
assert(sstr2.str() == expected);
}
{ // true false
std::basic_stringbuf<CharT> sstr1;
std::basic_stringbuf<CharT> sstr2;
std::basic_string<CharT> expected(42, CharT('*')); // a long string
{
std::basic_syncbuf<CharT> sync_buf1(&sstr1);
sync_buf1.set_emit_on_sync(false);
sync_buf1.sputc(CharT('A')); // a short string
std::basic_syncbuf<CharT> sync_buf2(&sstr2);
sync_buf2.set_emit_on_sync(true);
sync_buf2.sputn(expected.data(), expected.size());
sync_buf1.swap(sync_buf2);
assert(sstr1.str().empty());
assert(sstr2.str().empty());
sync_buf1.pubsync();
assert(sstr1.str().empty());
assert(sstr2.str() == expected);
sync_buf2.pubsync();
assert(sstr1.str().empty());
assert(sstr2.str() == expected);
}
assert(sstr1.str().size() == 1);
assert(sstr1.str()[0] == CharT('A'));
assert(sstr2.str() == expected);
}
{ // true true
std::basic_stringbuf<CharT> sstr1;
std::basic_stringbuf<CharT> sstr2;
std::basic_string<CharT> expected(42, CharT('*')); // a long string
{
std::basic_syncbuf<CharT> sync_buf1(&sstr1);
sync_buf1.set_emit_on_sync(true);
sync_buf1.sputc(CharT('A')); // a short string
std::basic_syncbuf<CharT> sync_buf2(&sstr2);
sync_buf2.set_emit_on_sync(true);
sync_buf2.sputn(expected.data(), expected.size());
sync_buf1.swap(sync_buf2);
assert(sstr1.str().empty());
assert(sstr2.str().empty());
sync_buf1.pubsync();
assert(sstr1.str().empty());
assert(sstr2.str() == expected);
sync_buf2.pubsync();
assert(sstr1.str().size() == 1);
assert(sstr1.str()[0] == CharT('A'));
assert(sstr2.str() == expected);
}
assert(sstr1.str().size() == 1);
assert(sstr1.str()[0] == CharT('A'));
assert(sstr2.str() == expected);
}
}
template <class CharT>
static void test() {
test_basic<CharT>();
test_emit_on_sync<CharT>();
test_short_write_after_swap<CharT>();
test_long_write_after_swap<CharT>();
}
int main(int, char**) {
test<char>();
#ifndef TEST_HAS_NO_WIDE_CHARACTERS
test<wchar_t>();
#endif
return 0;
}