[libcxx] r329028 - Implement filesystem NB comments, relative paths, and related issues.

Mike Edwards via cfe-commits cfe-commits at lists.llvm.org
Mon Apr 2 17:05:05 PDT 2018


Hi Eric,
Looks like this commit caused a test failure on Green Dragon in
libc++.std/experimental/filesystem/fs_op_funcs/fs_op_proximate.proximate.pass.cpp.
The test result from the build may be found here:
http://green.lab.llvm.org/green/job/libcxx_master_cmake_32/2643/testReport/junit/libc++/std_experimental_filesystem_fs_op_funcs_fs_op_proximate/proximate_pass_cpp/

Would you please have a look and either revert the commit or let me know if
a patch will be committed within the next hour?

Respectfully,
Mike Edwards

On Mon, Apr 2, 2018 at 4:03 PM, Eric Fiselier via cfe-commits <
cfe-commits at lists.llvm.org> wrote:

> Author: ericwf
> Date: Mon Apr  2 16:03:41 2018
> New Revision: 329028
>
> URL: http://llvm.org/viewvc/llvm-project?rev=329028&view=rev
> Log:
> Implement filesystem NB comments, relative paths, and related issues.
>
> This is a fairly large patch that implements all of the filesystem NB
> comments
> and the relative paths changes (ex. adding weakly_canonical). These issues
> and papers are all interrelated so their implementation couldn't be split
> up
> nicely.
>
> This patch upgrades <experimental/filesystem> to match the C++17 spec and
> not
> the published experimental TS spec. Some of the changes in this patch are
> both
> API and ABI breaking, however libc++ makes no guarantee about stability for
> experimental implementations.
>
> The major changes in this patch are:
>
> * Implement NB comments for filesystem (P0492R2), including:
>   * Implement `perm_options` enum as part of NB comments, and update the
>     `permissions` function to match.
>   * Implement changes to `remove_filename` and `replace_filename`
>   * Implement changes to `path::stem()` and `path::extension()` which
> support
>     splitting examples like `.profile`.
>   * Change path iteration to return an empty path instead of '.' for
> trailing
>     separators.
>   * Change `operator/=` to handle absolute paths on the RHS.
>   * Change `absolute` to no longer accept a current path argument.
>
> * Implement relative paths according to NB comments (P0219r1)
>
> * Combine `path.cpp` and `operations.cpp` since some path functions require
>   access to the operations internals, and some fs operations require access
>   to the path parser.
>
> Added:
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.gen/
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.gen/lexically_normal.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.gen/lexically_relative_and_proximate.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/fs.
> enum/enum.perm_options.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.proximate/
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.proximate/proximate.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.relative/
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.relative/relative.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.weakly_canonical/
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.weakly_canonical/weakly_canonical.pass.cpp
>     libcxx/trunk/test/support/verbose_assert.h
> Removed:
>     libcxx/trunk/src/experimental/filesystem/path.cpp
>     libcxx/trunk/test/libcxx/experimental/filesystem/class.
> path/path.member/path.append.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.system_complete/system_complete.pass.cpp
> Modified:
>     libcxx/trunk/benchmarks/CMakeLists.txt
>     libcxx/trunk/benchmarks/GenerateInput.hpp
>     libcxx/trunk/benchmarks/filesystem.bench.cpp
>     libcxx/trunk/include/experimental/filesystem
>     libcxx/trunk/src/experimental/filesystem/operations.cpp
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.itr/iterator.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.append.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.compare.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.decompose/empty.fail.cpp
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.decompose/path.decompose.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.generic.obs/generic_string_alloc.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.generic.obs/named_overloads.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.modifiers/remove_filename.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.modifiers/replace_filename.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.absolute/absolute.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.canonical/canonical.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.last_write_time/last_write_time.pass.cpp
>     libcxx/trunk/test/support/filesystem_test_helper.hpp
>     libcxx/trunk/www/cxx1z_status.html
>     libcxx/trunk/www/cxx2a_status.html
>
> Modified: libcxx/trunk/benchmarks/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/
> benchmarks/CMakeLists.txt?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/benchmarks/CMakeLists.txt (original)
> +++ libcxx/trunk/benchmarks/CMakeLists.txt Mon Apr  2 16:03:41 2018
> @@ -68,7 +68,7 @@ set(BENCHMARK_OUTPUT_DIR ${CMAKE_CURRENT
>  set(BENCHMARK_LIBCXX_INSTALL ${CMAKE_CURRENT_BINARY_DIR}/
> benchmark-libcxx)
>  set(BENCHMARK_NATIVE_INSTALL ${CMAKE_CURRENT_BINARY_DIR}/
> benchmark-native)
>  set(BENCHMARK_TEST_COMPILE_FLAGS
> -    -std=c++14 -O2
> +    -std=c++17 -O2
>      -I${BENCHMARK_LIBCXX_INSTALL}/include
>      -I${LIBCXX_SOURCE_DIR}/test/support
>  )
>
> Modified: libcxx/trunk/benchmarks/GenerateInput.hpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/
> benchmarks/GenerateInput.hpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/benchmarks/GenerateInput.hpp (original)
> +++ libcxx/trunk/benchmarks/GenerateInput.hpp Mon Apr  2 16:03:41 2018
> @@ -29,14 +29,16 @@ inline std::default_random_engine& getRa
>      return RandEngine;
>  }
>
> +
>  inline char getRandomChar() {
>      std::uniform_int_distribution<> LettersDist(0, LettersSize-1);
>      return Letters[LettersDist(getRandomEngine())];
>  }
>
>  template <class IntT>
> -inline IntT getRandomInteger() {
> -    std::uniform_int_distribution<IntT> dist;
> +inline IntT getRandomInteger(IntT Min = 0,
> +                             IntT Max = std::numeric_limits<IntT>::max())
> {
> +    std::uniform_int_distribution<IntT> dist(Min, Max);
>      return dist(getRandomEngine());
>  }
>
>
> Modified: libcxx/trunk/benchmarks/filesystem.bench.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/
> benchmarks/filesystem.bench.cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/benchmarks/filesystem.bench.cpp (original)
> +++ libcxx/trunk/benchmarks/filesystem.bench.cpp Mon Apr  2 16:03:41 2018
> @@ -1,17 +1,14 @@
> -#include <experimental/filesystem>
> -
>  #include "benchmark/benchmark.h"
>  #include "GenerateInput.hpp"
>  #include "test_iterators.h"
> -
> -namespace fs = std::experimental::filesystem;
> +#include "filesystem_include.hpp"
>
>  static const size_t TestNumInputs = 1024;
>
>
>  template <class GenInputs>
>  void BM_PathConstructString(benchmark::State &st, GenInputs gen) {
> -  using namespace fs;
> +  using fs::path;
>    const auto in = gen(st.range(0));
>    path PP;
>    for (auto& Part : in)
> @@ -21,14 +18,15 @@ void BM_PathConstructString(benchmark::S
>      const path P(PP.native());
>      benchmark::DoNotOptimize(P.native().data());
>    }
> +  st.SetComplexityN(st.range(0));
>  }
>  BENCHMARK_CAPTURE(BM_PathConstructString, large_string,
> -  getRandomStringInputs)->Arg(TestNumInputs);
> +  getRandomStringInputs)->Range(8, TestNumInputs)->Complexity();
>
>
>  template <class GenInputs>
>  void BM_PathConstructCStr(benchmark::State &st, GenInputs gen) {
> -  using namespace fs;
> +  using fs::path;
>    const auto in = gen(st.range(0));
>    path PP;
>    for (auto& Part : in)
> @@ -45,7 +43,7 @@ BENCHMARK_CAPTURE(BM_PathConstructCStr,
>
>  template <template <class...> class ItType, class GenInputs>
>  void BM_PathConstructIter(benchmark::State &st, GenInputs gen) {
> -  using namespace fs;
> +  using fs::path;
>    using Iter = ItType<std::string::const_iterator>;
>    const auto in = gen(st.range(0));
>    path PP;
> @@ -60,6 +58,7 @@ void BM_PathConstructIter(benchmark::Sta
>      const path P(Start, End);
>      benchmark::DoNotOptimize(P.native().data());
>    }
> +  st.SetComplexityN(st.range(0));
>  }
>  template <class GenInputs>
>  void BM_PathConstructInputIter(benchmark::State &st, GenInputs gen) {
> @@ -70,14 +69,14 @@ void BM_PathConstructForwardIter(benchma
>    BM_PathConstructIter<forward_iterator>(st, gen);
>  }
>  BENCHMARK_CAPTURE(BM_PathConstructInputIter, large_string,
> -  getRandomStringInputs)->Arg(TestNumInputs);
> +  getRandomStringInputs)->Range(8, TestNumInputs)->Complexity();
>  BENCHMARK_CAPTURE(BM_PathConstructForwardIter, large_string,
> -  getRandomStringInputs)->Arg(TestNumInputs);
> +  getRandomStringInputs)->Range(8, TestNumInputs)->Complexity();
>
>
>  template <class GenInputs>
>  void BM_PathIterateMultipleTimes(benchmark::State &st, GenInputs gen) {
> -  using namespace fs;
> +  using fs::path;
>    const auto in = gen(st.range(0));
>    path PP;
>    for (auto& Part : in)
> @@ -89,14 +88,15 @@ void BM_PathIterateMultipleTimes(benchma
>      }
>      benchmark::ClobberMemory();
>    }
> +  st.SetComplexityN(st.range(0));
>  }
>  BENCHMARK_CAPTURE(BM_PathIterateMultipleTimes, iterate_elements,
> -  getRandomStringInputs)->Arg(TestNumInputs);
> +  getRandomStringInputs)->Range(8, TestNumInputs)->Complexity();
>
>
>  template <class GenInputs>
>  void BM_PathIterateOnce(benchmark::State &st, GenInputs gen) {
> -  using namespace fs;
> +  using fs::path;
>    const auto in = gen(st.range(0));
>    path PP;
>    for (auto& Part : in)
> @@ -109,13 +109,14 @@ void BM_PathIterateOnce(benchmark::State
>      }
>      benchmark::ClobberMemory();
>    }
> +  st.SetComplexityN(st.range(0));
>  }
>  BENCHMARK_CAPTURE(BM_PathIterateOnce, iterate_elements,
> -  getRandomStringInputs)->Arg(TestNumInputs);
> +  getRandomStringInputs)->Range(8, TestNumInputs)->Complexity();
>
>  template <class GenInputs>
>  void BM_PathIterateOnceBackwards(benchmark::State &st, GenInputs gen) {
> -  using namespace fs;
> +  using fs::path;
>    const auto in = gen(st.range(0));
>    path PP;
>    for (auto& Part : in)
> @@ -135,4 +136,28 @@ void BM_PathIterateOnceBackwards(benchma
>  BENCHMARK_CAPTURE(BM_PathIterateOnceBackwards, iterate_elements,
>    getRandomStringInputs)->Arg(TestNumInputs);
>
> +static fs::path getRandomPaths(int NumParts, int PathLen) {
> +  fs::path Result;
> +  while (NumParts--) {
> +    std::string Part = getRandomString(PathLen);
> +    Result /= Part;
> +  }
> +  return Result;
> +}
> +
> +template <class GenInput>
> +void BM_LexicallyNormal(benchmark::State &st, GenInput gen, size_t
> PathLen) {
> +  using fs::path;
> +  auto In = gen(st.range(0), PathLen);
> +  benchmark::DoNotOptimize(&In);
> +  while (st.KeepRunning()) {
> +    benchmark::DoNotOptimize(In.lexically_normal());
> +  }
> +  st.SetComplexityN(st.range(0));
> +}
> +BENCHMARK_CAPTURE(BM_LexicallyNormal, small_path,
> +  getRandomPaths, /*PathLen*/5)->RangeMultiplier(2)->Range(2,
> 256)->Complexity();
> +BENCHMARK_CAPTURE(BM_LexicallyNormal, large_path,
> +  getRandomPaths, /*PathLen*/32)->RangeMultiplier(2)->Range(2,
> 256)->Complexity();
> +
>  BENCHMARK_MAIN();
>
> Modified: libcxx/trunk/include/experimental/filesystem
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/
> experimental/filesystem?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/include/experimental/filesystem (original)
> +++ libcxx/trunk/include/experimental/filesystem Mon Apr  2 16:03:41 2018
> @@ -76,11 +76,11 @@
>
>      // operational functions
>
> -    path absolute(const path& p, const path& base=current_path());
> +    path absolute(const path& p);
> +    path absolute(const path& p, error_code &ec);
>
> -    path canonical(const path& p, const path& base = current_path());
> +    path canonical(const path& p);
>      path canonical(const path& p, error_code& ec);
> -    path canonical(const path& p, const path& base, error_code& ec);
>
>      void copy(const path& from, const path& to);
>      void copy(const path& from, const path& to, error_code& ec);
> @@ -185,9 +185,17 @@
>      void permissions(const path& p, perms prms, perm_options opts,
>                       error_code& ec);
>
> +    path proximate(const path& p, error_code& ec);
> +    path proximate(const path& p, const path& base = current_path());
> +    path proximate(const path& p, const path& base, error_code &ec);
> +
>      path read_symlink(const path& p);
>      path read_symlink(const path& p, error_code& ec);
>
> +    path relative(const path& p, error_code& ec);
> +    path relative(const path& p, const path& base=current_path());
> +    path relative(const path& p, const path& base, error_code& ec);
> +
>      bool remove(const path& p);
>      bool remove(const path& p, error_code& ec) _NOEXCEPT;
>
> @@ -211,12 +219,13 @@
>      file_status  symlink_status(const path& p);
>      file_status  symlink_status(const path& p, error_code& ec) _NOEXCEPT;
>
> -    path system_complete(const path& p);
> -    path system_complete(const path& p, error_code& ec);
> -
>      path temp_directory_path();
>      path temp_directory_path(error_code& ec);
>
> +    path weakly_canonical(path const& p);
> +    path weakly_canonical(path const& p, error_code& ec);
> +
> +
>  } } } }  // namespaces std::experimental::filesystem::v1
>
>  */
> @@ -796,26 +805,26 @@ public:
>
>  private:
>      template <class _ECharT>
> -    void __append_sep_if_needed(_ECharT __first_or_null) {
> -        const _ECharT __null_val = {};
> -        bool __append_sep = !empty()                       &&
> -                            !__is_separator(__pn_.back())  &&
> -                            __first_or_null != __null_val  && // non-empty
> -                            !__is_separator(__first_or_null);
> -        if (__append_sep)
> -            __pn_ += preferred_separator;
> +    static bool __source_is_absolute(_ECharT __first_or_null) {
> +        return __is_separator(__first_or_null);
>      }
>
>  public:
>      // appends
>      path& operator/=(const path& __p) {
> -        _LIBCPP_ASSERT(!__p.has_root_name(),
> -                      "cannot append to a path with a root name");
> -        __append_sep_if_needed(__p.empty() ? char{} : __p.__pn_[0]);
> +        if (__p.is_absolute()) {
> +          __pn_ = __p.__pn_;
> +          return *this;
> +        }
> +        if (has_filename())
> +          __pn_ += preferred_separator;
>          __pn_ += __p.native();
>          return *this;
>      }
>
> +    // FIXME: Use _LIBCPP_DIAGNOSE_WARNING to produce a diagnostic when
> __src
> +    // is known at compile time to be "/' since the user almost certainly
> intended
> +    // to append a separator instead of overwriting the path with "/"
>      template <class _Source>
>      _LIBCPP_INLINE_VISIBILITY
>      _EnableIfPathable<_Source>
> @@ -828,7 +837,10 @@ public:
>      append(const _Source& __src) {
>          using _Traits = __is_pathable<_Source>;
>          using _CVT = _PathCVT<_SourceChar<_Source>>;
> -        __append_sep_if_needed(_Traits::__first_or_null(__src));
> +        if (__source_is_absolute(_Traits::__first_or_null(__src)))
> +          __pn_.clear();
> +        else if (has_filename())
> +          __pn_ += preferred_separator;
>          _CVT::__append_source(__pn_, __src);
>          return *this;
>      }
> @@ -838,10 +850,11 @@ public:
>          typedef typename iterator_traits<_InputIt>::value_type _ItVal;
>          static_assert(__can_convert_char<_ItVal>::value, "Must
> convertible");
>          using _CVT = _PathCVT<_ItVal>;
> -        if (__first != __last) {
> -            __append_sep_if_needed(*__first);
> -            _CVT::__append_range(__pn_, __first, __last);
> -        }
> +        if (__first != __last && __source_is_absolute(*__first))
> +          __pn_.clear();
> +        else if (has_filename())
> +          __pn_ += preferred_separator;
> +        _CVT::__append_range(__pn_, __first, __last);
>          return *this;
>      }
>
> @@ -916,10 +929,9 @@ public:
>
>      _LIBCPP_INLINE_VISIBILITY
>      path& remove_filename() {
> -      if (__pn_.size() == __root_path_raw().size())
> -        clear();
> -      else
> -        __pn_ = __parent_path();
> +      auto __fname = __filename();
> +      if (!__fname.empty())
> +        __pn_.erase(__fname.data() - __pn_.data());
>        return *this;
>      }
>
> @@ -935,6 +947,10 @@ public:
>          __pn_.swap(__rhs.__pn_);
>      }
>
> +    // private helper to allow reserving memory in the path
> +    _LIBCPP_INLINE_VISIBILITY
> +    void __reserve(size_t __s) { __pn_.reserve(__s); }
> +
>      // native format observers
>      _LIBCPP_INLINE_VISIBILITY
>      const string_type& native() const _NOEXCEPT {
> @@ -1023,6 +1039,17 @@ public:
>      _LIBCPP_INLINE_VISIBILITY bool is_absolute()        const { return
> has_root_directory(); }
>      _LIBCPP_INLINE_VISIBILITY bool is_relative()        const { return
> !is_absolute(); }
>
> +    // relative paths
> +    path lexically_normal() const;
> +    path lexically_relative(const path& __base) const;
> +
> +    _LIBCPP_INLINE_VISIBILITY path lexically_proximate(const path&
> __base) const {
> +      path __result = this->lexically_relative(__base);
> +      if (__result.native().empty())
> +        return *this;
> +      return __result;
> +    }
> +
>      // iterators
>      class _LIBCPP_TYPE_VIS iterator;
>      typedef iterator const_iterator;
> @@ -1277,7 +1304,9 @@ void __throw_filesystem_error(_Args&&...
>  // operational functions
>
>  _LIBCPP_FUNC_VIS
> -path __canonical(const path&, const path&, error_code *__ec=nullptr);
> +path __absolute(const path&, error_code *__ec=nullptr);
> +_LIBCPP_FUNC_VIS
> +path __canonical(const path&, error_code *__ec=nullptr);
>  _LIBCPP_FUNC_VIS
>  void __copy(const path& __from, const path& __to, copy_options __opt,
>          error_code *__ec=nullptr);
> @@ -1342,6 +1371,8 @@ _LIBCPP_FUNC_VIS
>  path __system_complete(const path&, error_code *__ec=nullptr);
>  _LIBCPP_FUNC_VIS
>  path __temp_directory_path(error_code *__ec=nullptr);
> +_LIBCPP_FUNC_VIS
> +path __weakly_canonical(path const& __p, error_code *__ec=nullptr);
>
>  inline _LIBCPP_INLINE_VISIBILITY
>  path current_path() {
> @@ -1363,24 +1394,24 @@ void current_path(const path& __p, error
>      __current_path(__p, &__ec);
>  }
>
> -_LIBCPP_FUNC_VIS
> -path absolute(const path&, const path& __p2 = current_path());
> +inline _LIBCPP_INLINE_VISIBILITY
> +path absolute(const path& __p) {
> +  return __absolute(__p);
> +}
>
>  inline _LIBCPP_INLINE_VISIBILITY
> -path canonical(const path& __p, const path& __base = current_path()) {
> -    return __canonical(__p, __base);
> +path absolute(const path& __p, error_code &__ec) {
> +  return __absolute(__p, &__ec);
>  }
>
>  inline _LIBCPP_INLINE_VISIBILITY
> -path canonical(const path& __p, error_code& __ec) {
> -    path __base = __current_path(&__ec);
> -    if (__ec) return {};
> -    return __canonical(__p, __base, &__ec);
> +path canonical(const path& __p) {
> +    return __canonical(__p);
>  }
>
>  inline _LIBCPP_INLINE_VISIBILITY
> -path canonical(const path& __p, const path& __base, error_code& __ec) {
> -    return __canonical(__p, __base, &__ec);
> +path canonical(const path& __p, error_code& __ec) {
> +    return __canonical(__p, &__ec);
>  }
>
>  inline _LIBCPP_INLINE_VISIBILITY
> @@ -1492,7 +1523,8 @@ void create_symlink(const path& __to, co
>  }
>
>  inline _LIBCPP_INLINE_VISIBILITY
> -void create_symlink(const path& __to, const path& __new, error_code&
> __ec) _NOEXCEPT {
> +void create_symlink(const path& __to, const path& __new,
> +                    error_code& __ec) _NOEXCEPT {
>      return __create_symlink(__to, __new, &__ec);
>  }
>
> @@ -1716,6 +1748,27 @@ void permissions(const path& __p, perms
>  }
>
>  inline _LIBCPP_INLINE_VISIBILITY
> +path proximate(const path& __p, const path& __base, error_code& __ec) {
> +   path __tmp = __weakly_canonical(__p, &__ec);
> +  if (__ec)
> +    return {};
> +  path __tmp_base = __weakly_canonical(__base, &__ec);
> +  if (__ec)
> +    return {};
> +  return __tmp.lexically_proximate(__tmp_base);
> +}
> +
> +inline _LIBCPP_INLINE_VISIBILITY
> +path proximate(const path& __p, error_code& __ec) {
> +  return proximate(__p, current_path(), __ec);
> +}
> +
> +inline _LIBCPP_INLINE_VISIBILITY
> +path proximate(const path& __p, const path& __base = current_path()) {
> +  return __weakly_canonical(__p).lexically_proximate(__weakly_
> canonical(__base));
> +}
> +
> +inline _LIBCPP_INLINE_VISIBILITY
>  path read_symlink(const path& __p) {
>      return __read_symlink(__p);
>  }
> @@ -1725,6 +1778,29 @@ path read_symlink(const path& __p, error
>      return __read_symlink(__p, &__ec);
>  }
>
> +
> +inline _LIBCPP_INLINE_VISIBILITY
> +path relative(const path& __p, const path& __base, error_code& __ec) {
> +  path __tmp = __weakly_canonical(__p, &__ec);
> +  if (__ec)
> +    return path();
> +  path __tmpbase = __weakly_canonical(__base, &__ec);
> +  if (__ec)
> +    return path();
> +  return __tmp.lexically_relative(__tmpbase);
> +}
> +
> +inline _LIBCPP_INLINE_VISIBILITY
> +path relative(const path& __p, error_code& __ec) {
> +  return relative(__p, current_path(), __ec);
> +}
> +
> +inline _LIBCPP_INLINE_VISIBILITY
> +path relative(const path& __p, const path& __base=current_path()) {
> +  return __weakly_canonical(__p).lexically_relative(__weakly_
> canonical(__base));
> +}
> +
> +
>  inline _LIBCPP_INLINE_VISIBILITY
>  bool remove(const path& __p) {
>      return __remove(__p);
> @@ -1796,23 +1872,23 @@ file_status symlink_status(const path& _
>  }
>
>  inline _LIBCPP_INLINE_VISIBILITY
> -path system_complete(const path& __p) {
> -    return __system_complete(__p);
> +path temp_directory_path() {
> +    return __temp_directory_path();
>  }
>
>  inline _LIBCPP_INLINE_VISIBILITY
> -path system_complete(const path& __p, error_code& __ec) {
> -    return __system_complete(__p, &__ec);
> +path temp_directory_path(error_code& __ec) {
> +    return __temp_directory_path(&__ec);
>  }
>
>  inline _LIBCPP_INLINE_VISIBILITY
> -path temp_directory_path() {
> -    return __temp_directory_path();
> +path weakly_canonical(path const& __p) {
> +  return __weakly_canonical(__p);
>  }
>
>  inline _LIBCPP_INLINE_VISIBILITY
> -path temp_directory_path(error_code& __ec) {
> -    return __temp_directory_path(&__ec);
> +path weakly_canonical(path const& __p, error_code& __ec) {
> +  return __weakly_canonical(__p, &__ec);
>  }
>
>
>
> Modified: libcxx/trunk/src/experimental/filesystem/operations.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/src/
> experimental/filesystem/operations.cpp?rev=329028&r1=
> 329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/src/experimental/filesystem/operations.cpp (original)
> +++ libcxx/trunk/src/experimental/filesystem/operations.cpp Mon Apr  2
> 16:03:41 2018
> @@ -10,8 +10,10 @@
>  #include "experimental/filesystem"
>  #include "iterator"
>  #include "fstream"
> -#include "type_traits"
>  #include "random"  /* for unique_path */
> +#include "string_view"
> +#include "type_traits"
> +#include "vector"
>  #include "cstdlib"
>  #include "climits"
>
> @@ -57,6 +59,250 @@ _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_FIL
>  filesystem_error::~filesystem_error() {}
>
>
> +namespace { namespace parser
> +{
> +
> +using string_view_t = path::__string_view;
> +using string_view_pair = pair<string_view_t, string_view_t>;
> +using PosPtr = path::value_type const*;
> +
> +struct PathParser {
> +  enum ParserState : unsigned char {
> +    // Zero is a special sentinel value used by default constructed
> iterators.
> +    PS_BeforeBegin = 1,
> +    PS_InRootName,
> +    PS_InRootDir,
> +    PS_InFilenames,
> +    PS_InTrailingSep,
> +    PS_AtEnd
> +  };
> +
> +  const string_view_t Path;
> +  string_view_t RawEntry;
> +  ParserState State;
> +
> +private:
> +  PathParser(string_view_t P, ParserState State) noexcept
> +      : Path(P), State(State) {}
> +
> +public:
> +  PathParser(string_view_t P, string_view_t E, unsigned char S)
> +      : Path(P), RawEntry(E), State(static_cast<ParserState>(S)) {
> +    // S cannot be '0' or PS_BeforeBegin.
> +  }
> +
> +  static PathParser CreateBegin(string_view_t P) noexcept {
> +    PathParser PP(P, PS_BeforeBegin);
> +    PP.increment();
> +    return PP;
> +  }
> +
> +  static PathParser CreateEnd(string_view_t P) noexcept {
> +    PathParser PP(P, PS_AtEnd);
> +    return PP;
> +  }
> +
> +  PosPtr peek() const noexcept {
> +    auto TkEnd = getNextTokenStartPos();
> +    auto End = getAfterBack();
> +    return TkEnd == End ? nullptr : TkEnd;
> +  }
> +
> +  void increment() noexcept {
> +    const PosPtr End = getAfterBack();
> +    const PosPtr Start = getNextTokenStartPos();
> +    if (Start == End)
> +      return makeState(PS_AtEnd);
> +
> +    switch (State) {
> +    case PS_BeforeBegin: {
> +      PosPtr TkEnd = consumeSeparator(Start, End);
> +      if (TkEnd)
> +        return makeState(PS_InRootDir, Start, TkEnd);
> +      else
> +        return makeState(PS_InFilenames, Start, consumeName(Start, End));
> +    }
> +    case PS_InRootDir:
> +      return makeState(PS_InFilenames, Start, consumeName(Start, End));
> +
> +    case PS_InFilenames: {
> +      PosPtr SepEnd = consumeSeparator(Start, End);
> +      if (SepEnd != End) {
> +        PosPtr TkEnd = consumeName(SepEnd, End);
> +        if (TkEnd)
> +          return makeState(PS_InFilenames, SepEnd, TkEnd);
> +      }
> +      return makeState(PS_InTrailingSep, Start, SepEnd);
> +    }
> +
> +    case PS_InTrailingSep:
> +      return makeState(PS_AtEnd);
> +
> +    case PS_InRootName:
> +    case PS_AtEnd:
> +      _LIBCPP_UNREACHABLE();
> +    }
> +  }
> +
> +  void decrement() noexcept {
> +    const PosPtr REnd = getBeforeFront();
> +    const PosPtr RStart = getCurrentTokenStartPos() - 1;
> +    if (RStart == REnd) // we're decrementing the begin
> +      return makeState(PS_BeforeBegin);
> +
> +    switch (State) {
> +    case PS_AtEnd: {
> +      // Try to consume a trailing separator or root directory first.
> +      if (PosPtr SepEnd = consumeSeparator(RStart, REnd)) {
> +        if (SepEnd == REnd)
> +          return makeState(PS_InRootDir, Path.data(), RStart + 1);
> +        return makeState(PS_InTrailingSep, SepEnd + 1, RStart + 1);
> +      } else {
> +        PosPtr TkStart = consumeName(RStart, REnd);
> +        return makeState(PS_InFilenames, TkStart + 1, RStart + 1);
> +      }
> +    }
> +    case PS_InTrailingSep:
> +      return makeState(PS_InFilenames, consumeName(RStart, REnd) + 1,
> RStart + 1);
> +    case PS_InFilenames: {
> +      PosPtr SepEnd = consumeSeparator(RStart, REnd);
> +      if (SepEnd == REnd)
> +        return makeState(PS_InRootDir, Path.data(), RStart + 1);
> +      PosPtr TkEnd = consumeName(SepEnd, REnd);
> +      return makeState(PS_InFilenames, TkEnd + 1, SepEnd + 1);
> +    }
> +    case PS_InRootDir:
> +      // return makeState(PS_InRootName, Path.data(), RStart + 1);
> +    case PS_InRootName:
> +    case PS_BeforeBegin:
> +      _LIBCPP_UNREACHABLE();
> +    }
> +  }
> +
> +  /// \brief Return a view with the "preferred representation" of the
> current
> +  ///   element. For example trailing separators are represented as a '.'
> +  string_view_t operator*() const noexcept {
> +    switch (State) {
> +    case PS_BeforeBegin:
> +    case PS_AtEnd:
> +      return "";
> +    case PS_InRootDir:
> +      return "/";
> +    case PS_InTrailingSep:
> +      return "";
> +    case PS_InRootName:
> +    case PS_InFilenames:
> +      return RawEntry;
> +    }
> +    _LIBCPP_UNREACHABLE();
> +  }
> +
> +  explicit operator bool() const noexcept {
> +    return State != PS_BeforeBegin && State != PS_AtEnd;
> +  }
> +
> +  PathParser& operator++() noexcept {
> +    increment();
> +    return *this;
> +  }
> +
> +  PathParser& operator--() noexcept {
> +    decrement();
> +    return *this;
> +  }
> +
> +  bool inRootPath() const noexcept {
> +    return State == PS_InRootDir || State == PS_InRootName;
> +  }
> +
> +private:
> +  void makeState(ParserState NewState, PosPtr Start, PosPtr End) noexcept
> {
> +    State = NewState;
> +    RawEntry = string_view_t(Start, End - Start);
> +  }
> +  void makeState(ParserState NewState) noexcept {
> +    State = NewState;
> +    RawEntry = {};
> +  }
> +
> +  PosPtr getAfterBack() const noexcept {
> +    return Path.data() + Path.size();
> +  }
> +
> +  PosPtr getBeforeFront() const noexcept {
> +    return Path.data() - 1;
> +  }
> +
> +  /// \brief Return a pointer to the first character after the currently
> +  ///   lexed element.
> +  PosPtr getNextTokenStartPos() const noexcept {
> +    switch (State) {
> +    case PS_BeforeBegin:
> +      return Path.data();
> +    case PS_InRootName:
> +    case PS_InRootDir:
> +    case PS_InFilenames:
> +      return &RawEntry.back() + 1;
> +    case PS_InTrailingSep:
> +    case PS_AtEnd:
> +      return getAfterBack();
> +    }
> +    _LIBCPP_UNREACHABLE();
> +  }
> +
> +  /// \brief Return a pointer to the first character in the currently
> lexed
> +  ///   element.
> +  PosPtr getCurrentTokenStartPos() const noexcept {
> +    switch (State) {
> +    case PS_BeforeBegin:
> +    case PS_InRootName:
> +      return &Path.front();
> +    case PS_InRootDir:
> +    case PS_InFilenames:
> +    case PS_InTrailingSep:
> +      return &RawEntry.front();
> +    case PS_AtEnd:
> +      return &Path.back() + 1;
> +    }
> +    _LIBCPP_UNREACHABLE();
> +  }
> +
> +  PosPtr consumeSeparator(PosPtr P, PosPtr End) const noexcept {
> +    if (P == End || *P != '/')
> +      return nullptr;
> +    const int Inc = P < End ? 1 : -1;
> +    P += Inc;
> +    while (P != End && *P == '/')
> +      P += Inc;
> +    return P;
> +  }
> +
> +  PosPtr consumeName(PosPtr P, PosPtr End) const noexcept {
> +    if (P == End || *P == '/')
> +      return nullptr;
> +    const int Inc = P < End ? 1 : -1;
> +    P += Inc;
> +    while (P != End && *P != '/')
> +      P += Inc;
> +    return P;
> +  }
> +};
> +
> +string_view_pair separate_filename(string_view_t const & s) {
> +    if (s == "." || s == ".." || s.empty()) return string_view_pair{s,
> ""};
> +    auto pos = s.find_last_of('.');
> +    if (pos == string_view_t::npos || pos == 0)
> +        return string_view_pair{s, string_view_t{}};
> +    return string_view_pair{s.substr(0, pos), s.substr(pos)};
> +}
> +
> +string_view_t createView(PosPtr S, PosPtr E) noexcept {
> +  return {S, static_cast<size_t>(E - S) + 1};
> +}
> +
> +}} // namespace parser
> +
> +
>  //                       POSIX HELPERS
>
>  namespace detail { namespace  {
> @@ -186,14 +432,33 @@ bool copy_file_impl(const path& from, co
>  }} // end namespace detail
>
>  using detail::set_or_throw;
> +using parser::string_view_t;
> +using parser::PathParser;
> +using parser::createView;
> +
> +static path __do_absolute(const path& p, path *cwd, std::error_code *ec) {
> +  if (ec) ec->clear();
> +    if (p.is_absolute())
> +      return p;
> +    *cwd = __current_path(ec);
> +    if (ec && *ec)
> +      return {};
> +    return (*cwd) / p;
> +}
> +
> +path __absolute(const path& p, std::error_code *ec) {
> +    path cwd;
> +    return __do_absolute(p, &cwd, ec);
> +}
>
> -path __canonical(path const & orig_p, const path& base, std::error_code
> *ec)
> +path __canonical(path const & orig_p, std::error_code *ec)
>  {
> -    path p = absolute(orig_p, base);
> +    path cwd;
> +    path p = __do_absolute(orig_p, &cwd, ec);
>      char buff[PATH_MAX + 1];
>      char *ret;
>      if ((ret = ::realpath(p.c_str(), buff)) == nullptr) {
> -        set_or_throw(ec, "canonical", orig_p, base);
> +        set_or_throw(ec, "canonical", orig_p, cwd);
>          return {};
>      }
>      if (ec) ec->clear();
> @@ -791,11 +1056,6 @@ file_status __symlink_status(const path&
>      return detail::posix_lstat(p, ec);
>  }
>
> -path __system_complete(const path& p, std::error_code *ec) {
> -    if (ec) ec->clear();
> -    return absolute(p, current_path());
> -}
> -
>  path __temp_directory_path(std::error_code* ec) {
>    const char* env_paths[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR"};
>    const char* ret = nullptr;
> @@ -820,34 +1080,393 @@ path __temp_directory_path(std::error_co
>    return p;
>  }
>
> -// An absolute path is composed according to the table in
> [fs.op.absolute].
> -path absolute(const path& p, const path& base) {
> -    auto root_name = p.root_name();
> -    auto root_dir = p.root_directory();
>
> -    if (!root_name.empty() && !root_dir.empty())
> -      return p;
> +path __weakly_canonical(const path& p, std::error_code *ec) {
> +  if (p.empty())
> +    return __canonical("", ec);
> +
> +  path result;
> +  path tmp;
> +  tmp.__reserve(p.native().size());
> +  auto PP = PathParser::CreateEnd(p.native());
> +  --PP;
> +  std::vector<string_view_t> DNEParts;
>
> -    auto abs_base = base.is_absolute() ? base : absolute(base);
> +  while (PP.State != PathParser::PS_BeforeBegin) {
> +    tmp.assign(createView(p.native().data(), &PP.RawEntry.back()));
> +    std::error_code m_ec;
> +    file_status st = __status(tmp, &m_ec);
> +    if (!status_known(st)) {
> +      set_or_throw(m_ec, ec, "weakly_canonical", p);
> +      return {};
> +    } else if (exists(st)) {
> +      result = __canonical(tmp, ec);
> +      break;
> +    }
> +    DNEParts.push_back(*PP);
> +    --PP;
> +  }
> +  if (PP.State == PathParser::PS_BeforeBegin)
> +    result = __canonical("", ec);
> +  if (ec) ec->clear();
> +  if (DNEParts.empty())
> +    return result;
> +  for (auto It=DNEParts.rbegin(); It != DNEParts.rend(); ++It)
> +    result /= *It;
> +  return result.lexically_normal();
> +}
> +
> +
> +
> +///////////////////////////////////////////////////////////
> ////////////////////
> +//                            path definitions
> +///////////////////////////////////////////////////////////
> ////////////////////
> +
> +constexpr path::value_type path::preferred_separator;
> +
> +path & path::replace_extension(path const & replacement)
> +{
> +    path p = extension();
> +    if (not p.empty()) {
> +      __pn_.erase(__pn_.size() - p.native().size());
> +    }
> +    if (!replacement.empty()) {
> +        if (replacement.native()[0] != '.') {
> +            __pn_ += ".";
> +        }
> +        __pn_.append(replacement.__pn_);
> +    }
> +    return *this;
> +}
> +
> +///////////////////////////////////////////////////////////
> ////////////////////
> +// path.decompose
> +
> +string_view_t path::__root_name() const
> +{
> +    auto PP = PathParser::CreateBegin(__pn_);
> +    if (PP.State == PathParser::PS_InRootName)
> +      return *PP;
> +    return {};
> +}
>
> -    /* !has_root_name && !has_root_dir */
> -    if (root_name.empty() && root_dir.empty())
> +string_view_t path::__root_directory() const
> +{
> +    auto PP = PathParser::CreateBegin(__pn_);
> +    if (PP.State == PathParser::PS_InRootName)
> +      ++PP;
> +    if (PP.State == PathParser::PS_InRootDir)
> +      return *PP;
> +    return {};
> +}
> +
> +string_view_t path::__root_path_raw() const
> +{
> +    auto PP = PathParser::CreateBegin(__pn_);
> +    if (PP.State == PathParser::PS_InRootName) {
> +      auto NextCh = PP.peek();
> +      if (NextCh && *NextCh == '/') {
> +        ++PP;
> +        return createView(__pn_.data(), &PP.RawEntry.back());
> +      }
> +      return PP.RawEntry;
> +    }
> +    if (PP.State == PathParser::PS_InRootDir)
> +      return *PP;
> +    return {};
> +}
> +
> +static bool ConsumeRootDir(PathParser* PP) {
> +  while (PP->State <= PathParser::PS_InRootDir)
> +    ++(*PP);
> +  return PP->State == PathParser::PS_AtEnd;
> +}
> +
> +string_view_t path::__relative_path() const
> +{
> +    auto PP = PathParser::CreateBegin(__pn_);
> +    if (ConsumeRootDir(&PP))
> +      return {};
> +    return createView(PP.RawEntry.data(), &__pn_.back());
> +}
> +
> +string_view_t path::__parent_path() const
> +{
> +    if (empty())
> +      return {};
> +    // Determine if we have a root path but not a relative path. In that
> case
> +    // return *this.
>      {
> -      return abs_base / p;
> +      auto PP = PathParser::CreateBegin(__pn_);
> +      if (ConsumeRootDir(&PP))
> +        return __pn_;
>      }
> -    else if (!root_name.empty()) /* has_root_name && !has_root_dir */
> +    // Otherwise remove a single element from the end of the path, and
> return
> +    // a string representing that path
>      {
> -      return  root_name / abs_base.root_directory()
> -              /
> -              abs_base.relative_path() / p.relative_path();
> +      auto PP = PathParser::CreateEnd(__pn_);
> +      --PP;
> +      if (PP.RawEntry.data() == __pn_.data())
> +        return {};
> +      --PP;
> +      return createView(__pn_.data(), &PP.RawEntry.back());
>      }
> -    else /* !has_root_name && has_root_dir */
> +}
> +
> +string_view_t path::__filename() const
> +{
> +    if (empty()) return {};
>      {
> -      if (abs_base.has_root_name())
> -        return abs_base.root_name() / p;
> -      // else p is absolute,  return outside of block
> +      PathParser PP = PathParser::CreateBegin(__pn_);
> +      if (ConsumeRootDir(&PP))
> +        return {};
>      }
> -    return p;
> +    return *(--PathParser::CreateEnd(__pn_));
>  }
>
> +string_view_t path::__stem() const
> +{
> +    return parser::separate_filename(__filename()).first;
> +}
> +
> +string_view_t path::__extension() const
> +{
> +    return parser::separate_filename(__filename()).second;
> +}
> +
> +///////////////////////////////////////////////////////////
> /////////////////
> +// path.gen
> +
> +
> +enum PathPartKind : unsigned char {
> +  PK_None,
> +  PK_RootSep,
> +  PK_Filename,
> +  PK_Dot,
> +  PK_DotDot,
> +  PK_TrailingSep
> +};
> +
> +static PathPartKind ClassifyPathPart(string_view_t Part) {
> +  if (Part.empty())
> +    return PK_TrailingSep;
> +  if (Part == ".")
> +    return PK_Dot;
> +  if (Part == "..")
> +    return PK_DotDot;
> +  if (Part == "/")
> +    return PK_RootSep;
> +  return PK_Filename;
> +}
> +
> +path path::lexically_normal() const {
> +  if (__pn_.empty())
> +    return *this;
> +
> +  using PartKindPair = std::pair<string_view_t, PathPartKind>;
> +  std::vector<PartKindPair> Parts;
> +  // Guess as to how many elements the path has to avoid reallocating.
> +  Parts.reserve(32);
> +
> +  // Track the total size of the parts as we collect them. This allows the
> +  // resulting path to reserve the correct amount of memory.
> +  size_t NewPathSize = 0;
> +  auto AddPart = [&](PathPartKind K, string_view_t P) {
> +    NewPathSize += P.size();
> +    Parts.emplace_back(P, K);
> +  };
> +  auto LastPartKind = [&]() {
> +    if (Parts.empty())
> +      return PK_None;
> +    return Parts.back().second;
> +  };
> +
> +  bool MaybeNeedTrailingSep = false;
> +  // Build a stack containing the remaining elements of the path, popping
> off
> +  // elements which occur before a '..' entry.
> +  for (auto PP = PathParser::CreateBegin(__pn_); PP; ++PP) {
> +    auto Part = *PP;
> +    PathPartKind Kind = ClassifyPathPart(Part);
> +    switch (Kind) {
> +    case PK_Filename:
> +    case PK_RootSep: {
> +      // Add all non-dot and non-dot-dot elements to the stack of
> elements.
> +      AddPart(Kind, Part);
> +      MaybeNeedTrailingSep = false;
> +      break;
> +    }
> +    case PK_DotDot: {
> +      // Only push a ".." element if there are no elements preceding the
> "..",
> +      // or if the preceding element is itself "..".
> +      auto LastKind = LastPartKind();
> +      if (LastKind == PK_Filename) {
> +        NewPathSize -= Parts.back().first.size();
> +        Parts.pop_back();
> +      } else if (LastKind != PK_RootSep)
> +        AddPart(PK_DotDot, "..");
> +      MaybeNeedTrailingSep = LastKind == PK_Filename;
> +      break;
> +    }
> +    case PK_Dot:
> +    case PK_TrailingSep: {
> +      MaybeNeedTrailingSep = true;
> +      break;
> +    }
> +    case PK_None:
> +      _LIBCPP_UNREACHABLE();
> +    }
> +  }
> +  // [fs.path.generic]p6.8: If the path is empty, add a dot.
> +  if (Parts.empty())
> +     return ".";
> +
> +  // [fs.path.generic]p6.7: If the last filename is dot-dot, remove any
> +  // trailing directory-separator.
> +  bool NeedTrailingSep = MaybeNeedTrailingSep && LastPartKind() ==
> PK_Filename;
> +
> +  path Result;
> +  Result.__pn_.reserve(Parts.size() + NewPathSize + NeedTrailingSep);
> +  for (auto &PK : Parts)
> +    Result /= PK.first;
> +
> +  if (NeedTrailingSep)
> +    Result /= "";
> +
> +  return Result;
> +}
> +
> +static int DetermineLexicalElementCount(PathParser PP) {
> +  int Count = 0;
> +  for (; PP; ++PP) {
> +    auto Elem = *PP;
> +    if (Elem == "..")
> +      --Count;
> +    else if (Elem != ".")
> +      ++Count;
> +  }
> +  return Count;
> +}
> +
> +path path::lexically_relative(const path& base) const {
> +  { // perform root-name/root-directory mismatch checks
> +    auto PP = PathParser::CreateBegin(__pn_);
> +    auto PPBase = PathParser::CreateBegin(base.__pn_);
> +    auto CheckIterMismatchAtBase = [&]() {
> +        return PP.State != PPBase.State && (
> +            PP.inRootPath() || PPBase.inRootPath());
> +    };
> +    if (PP.State == PathParser::PS_InRootName &&
> +        PPBase.State == PathParser::PS_InRootName) {
> +      if (*PP != *PPBase)
> +        return {};
> +    } else if (CheckIterMismatchAtBase())
> +      return {};
> +
> +    if (PP.inRootPath()) ++PP;
> +    if (PPBase.inRootPath()) ++PPBase;
> +    if (CheckIterMismatchAtBase())
> +      return {};
> +  }
> +
> +  // Find the first mismatching element
> +  auto PP = PathParser::CreateBegin(__pn_);
> +  auto PPBase = PathParser::CreateBegin(base.__pn_);
> +  while (PP && PPBase && PP.State == PPBase.State &&
> +         *PP == *PPBase) {
> +    ++PP;
> +    ++PPBase;
> +  }
> +
> +  // If there is no mismatch, return ".".
> +  if (!PP && !PPBase)
> +    return ".";
> +
> +  // Otherwise, determine the number of elements, 'n', which are not dot
> or
> +  // dot-dot minus the number of dot-dot elements.
> +  int ElemCount = DetermineLexicalElementCount(PPBase);
> +  if (ElemCount < 0)
> +    return {};
> +
> +  // return a path constructed with 'n' dot-dot elements, followed by the
> the
> +  // elements of '*this' after the mismatch.
> +  path Result;
> +  // FIXME: Reserve enough room in Result that it won't have to
> re-allocate.
> +  while (ElemCount--)
> +    Result /= "..";
> +  for (; PP; ++PP)
> +    Result /= *PP;
> +  return Result;
> +}
> +
> +///////////////////////////////////////////////////////////
> /////////////////
> +// path.comparisons
> +int path::__compare(string_view_t __s) const {
> +    auto PP = PathParser::CreateBegin(__pn_);
> +    auto PP2 = PathParser::CreateBegin(__s);
> +    while (PP && PP2) {
> +        int res = (*PP).compare(*PP2);
> +        if (res != 0) return res;
> +        ++PP; ++PP2;
> +    }
> +    if (PP.State == PP2.State && !PP)
> +        return 0;
> +    if (!PP)
> +        return -1;
> +    return 1;
> +}
> +
> +///////////////////////////////////////////////////////////
> /////////////////
> +// path.nonmembers
> +size_t hash_value(const path& __p) noexcept {
> +  auto PP = PathParser::CreateBegin(__p.native());
> +  size_t hash_value = 0;
> +  std::hash<string_view_t> hasher;
> +  while (PP) {
> +    hash_value = __hash_combine(hash_value, hasher(*PP));
> +    ++PP;
> +  }
> +  return hash_value;
> +}
> +
> +///////////////////////////////////////////////////////////
> /////////////////
> +// path.itr
> +path::iterator path::begin() const
> +{
> +    auto PP = PathParser::CreateBegin(__pn_);
> +    iterator it;
> +    it.__path_ptr_ = this;
> +    it.__state_ = PP.State;
> +    it.__entry_ = PP.RawEntry;
> +    it.__stashed_elem_.__assign_view(*PP);
> +    return it;
> +}
> +
> +path::iterator path::end() const
> +{
> +    iterator it{};
> +    it.__state_ = PathParser::PS_AtEnd;
> +    it.__path_ptr_ = this;
> +    return it;
> +}
> +
> +path::iterator& path::iterator::__increment() {
> +  static_assert(__at_end == PathParser::PS_AtEnd, "");
> +  PathParser PP(__path_ptr_->native(), __entry_, __state_);
> +  ++PP;
> +  __state_ = PP.State;
> +  __entry_ = PP.RawEntry;
> +  __stashed_elem_.__assign_view(*PP);
> +  return *this;
> +}
> +
> +path::iterator& path::iterator::__decrement() {
> +  PathParser PP(__path_ptr_->native(), __entry_, __state_);
> +  --PP;
> +  __state_ = PP.State;
> +  __entry_ = PP.RawEntry;
> +  __stashed_elem_.__assign_view(*PP);
> +  return *this;
> +}
> +
> +
>  _LIBCPP_END_NAMESPACE_EXPERIMENTAL_FILESYSTEM
>
> Removed: libcxx/trunk/src/experimental/filesystem/path.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/src/
> experimental/filesystem/path.cpp?rev=329027&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/src/experimental/filesystem/path.cpp (original)
> +++ libcxx/trunk/src/experimental/filesystem/path.cpp (removed)
> @@ -1,448 +0,0 @@
> -//===--------------------- filesystem/path.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.
> -//
> -//===------------------------------------------------------
> ----------------===//
> -#include "experimental/filesystem"
> -#include "string_view"
> -#include "utility"
> -
> -namespace { namespace parser
> -{
> -using namespace std;
> -using namespace std::experimental::filesystem;
> -
> -using string_view_t = path::__string_view;
> -using string_view_pair = pair<string_view_t, string_view_t>;
> -using PosPtr = path::value_type const*;
> -
> -struct PathParser {
> -  enum ParserState : unsigned char {
> -    // Zero is a special sentinel value used by default constructed
> iterators.
> -    PS_BeforeBegin = 1,
> -    PS_InRootName,
> -    PS_InRootDir,
> -    PS_InFilenames,
> -    PS_InTrailingSep,
> -    PS_AtEnd
> -  };
> -
> -  const string_view_t Path;
> -  string_view_t RawEntry;
> -  ParserState State;
> -
> -private:
> -  PathParser(string_view_t P, ParserState State) noexcept
> -      : Path(P), State(State) {}
> -
> -public:
> -  PathParser(string_view_t P, string_view_t E, unsigned char S)
> -      : Path(P), RawEntry(E), State(static_cast<ParserState>(S)) {
> -    // S cannot be '0' or PS_BeforeBegin.
> -  }
> -
> -  static PathParser CreateBegin(string_view_t P) noexcept {
> -    PathParser PP(P, PS_BeforeBegin);
> -    PP.increment();
> -    return PP;
> -  }
> -
> -  static PathParser CreateEnd(string_view_t P) noexcept {
> -    PathParser PP(P, PS_AtEnd);
> -    return PP;
> -  }
> -
> -  PosPtr peek() const noexcept {
> -    auto TkEnd = getNextTokenStartPos();
> -    auto End = getAfterBack();
> -    return TkEnd == End ? nullptr : TkEnd;
> -  }
> -
> -  void increment() noexcept {
> -    const PosPtr End = getAfterBack();
> -    const PosPtr Start = getNextTokenStartPos();
> -    if (Start == End)
> -      return makeState(PS_AtEnd);
> -
> -    switch (State) {
> -    case PS_BeforeBegin: {
> -      PosPtr TkEnd = consumeSeparator(Start, End);
> -      // If we consumed exactly two separators we have a root name.
> -      if (TkEnd && TkEnd == Start + 2) {
> -        // FIXME Do we need to consume a name or is '//' a root name on
> its own?
> -        // what about '//.', '//..', '//...'?
> -        auto NameEnd = consumeName(TkEnd, End);
> -        if (NameEnd)
> -          TkEnd = NameEnd;
> -        return makeState(PS_InRootName, Start, TkEnd);
> -      }
> -      else if (TkEnd)
> -        return makeState(PS_InRootDir, Start, TkEnd);
> -      else
> -        return makeState(PS_InFilenames, Start, consumeName(Start, End));
> -    }
> -
> -    case PS_InRootName:
> -      return makeState(PS_InRootDir, Start, consumeSeparator(Start, End));
> -    case PS_InRootDir:
> -      return makeState(PS_InFilenames, Start, consumeName(Start, End));
> -
> -    case PS_InFilenames: {
> -      PosPtr SepEnd = consumeSeparator(Start, End);
> -      if (SepEnd != End) {
> -        PosPtr TkEnd = consumeName(SepEnd, End);
> -        if (TkEnd)
> -          return makeState(PS_InFilenames, SepEnd, TkEnd);
> -      }
> -      return makeState(PS_InTrailingSep, Start, SepEnd);
> -    }
> -
> -    case PS_InTrailingSep:
> -      return makeState(PS_AtEnd);
> -
> -    case PS_AtEnd:
> -      _LIBCPP_UNREACHABLE();
> -    }
> -  }
> -
> -  void decrement() noexcept {
> -    const PosPtr REnd = getBeforeFront();
> -    const PosPtr RStart = getCurrentTokenStartPos() - 1;
> -
> -    switch (State) {
> -    case PS_AtEnd: {
> -      // Try to consume a trailing separator or root directory first.
> -      if (PosPtr SepEnd = consumeSeparator(RStart, REnd)) {
> -        if (SepEnd == REnd)
> -          return makeState((RStart == REnd + 2) ? PS_InRootName :
> PS_InRootDir,
> -                           Path.data(), RStart + 1);
> -        // Check if we're seeing the root directory separator
> -        auto PP = CreateBegin(Path);
> -        bool InRootDir = PP.State == PS_InRootName &&
> -            &PP.RawEntry.back() == SepEnd;
> -        return makeState(InRootDir ? PS_InRootDir : PS_InTrailingSep,
> -                         SepEnd + 1, RStart + 1);
> -      } else {
> -        PosPtr TkStart = consumeName(RStart, REnd);
> -        if (TkStart == REnd + 2 && consumeSeparator(TkStart, REnd) ==
> REnd)
> -          return makeState(PS_InRootName, Path.data(), RStart + 1);
> -        else
> -          return makeState(PS_InFilenames, TkStart + 1, RStart + 1);
> -      }
> -    }
> -    case PS_InTrailingSep:
> -      return makeState(PS_InFilenames, consumeName(RStart, REnd) + 1,
> RStart + 1);
> -    case PS_InFilenames: {
> -      PosPtr SepEnd = consumeSeparator(RStart, REnd);
> -      if (SepEnd == REnd)
> -        return makeState((RStart == REnd + 2) ? PS_InRootName :
> PS_InRootDir,
> -                         Path.data(), RStart + 1);
> -      PosPtr TkEnd = consumeName(SepEnd, REnd);
> -      if (TkEnd == REnd + 2 && consumeSeparator(TkEnd, REnd) == REnd)
> -        return makeState(PS_InRootDir, SepEnd + 1, RStart + 1);
> -      return makeState(PS_InFilenames, TkEnd + 1, SepEnd + 1);
> -    }
> -    case PS_InRootDir:
> -      return makeState(PS_InRootName, Path.data(), RStart + 1);
> -    case PS_InRootName:
> -    case PS_BeforeBegin:
> -      _LIBCPP_UNREACHABLE();
> -    }
> -  }
> -
> -  /// \brief Return a view with the "preferred representation" of the
> current
> -  ///   element. For example trailing separators are represented as a '.'
> -  string_view_t operator*() const noexcept {
> -    switch (State) {
> -    case PS_BeforeBegin:
> -    case PS_AtEnd:
> -      return "";
> -    case PS_InRootDir:
> -      return "/";
> -    case PS_InTrailingSep:
> -      return ".";
> -    case PS_InRootName:
> -    case PS_InFilenames:
> -      return RawEntry;
> -    }
> -    _LIBCPP_UNREACHABLE();
> -  }
> -
> -  explicit operator bool() const noexcept {
> -    return State != PS_BeforeBegin && State != PS_AtEnd;
> -  }
> -
> -  PathParser& operator++() noexcept {
> -    increment();
> -    return *this;
> -  }
> -
> -  PathParser& operator--() noexcept {
> -    decrement();
> -    return *this;
> -  }
> -
> -private:
> -  void makeState(ParserState NewState, PosPtr Start, PosPtr End) noexcept
> {
> -    State = NewState;
> -    RawEntry = string_view_t(Start, End - Start);
> -  }
> -  void makeState(ParserState NewState) noexcept {
> -    State = NewState;
> -    RawEntry = {};
> -  }
> -
> -  PosPtr getAfterBack() const noexcept {
> -    return Path.data() + Path.size();
> -  }
> -
> -  PosPtr getBeforeFront() const noexcept {
> -    return Path.data() - 1;
> -  }
> -
> -  /// \brief Return a pointer to the first character after the currently
> -  ///   lexed element.
> -  PosPtr getNextTokenStartPos() const noexcept {
> -    switch (State) {
> -    case PS_BeforeBegin:
> -      return Path.data();
> -    case PS_InRootName:
> -    case PS_InRootDir:
> -    case PS_InFilenames:
> -      return &RawEntry.back() + 1;
> -    case PS_InTrailingSep:
> -    case PS_AtEnd:
> -      return getAfterBack();
> -    }
> -    _LIBCPP_UNREACHABLE();
> -  }
> -
> -  /// \brief Return a pointer to the first character in the currently
> lexed
> -  ///   element.
> -  PosPtr getCurrentTokenStartPos() const noexcept {
> -    switch (State) {
> -    case PS_BeforeBegin:
> -    case PS_InRootName:
> -      return &Path.front();
> -    case PS_InRootDir:
> -    case PS_InFilenames:
> -    case PS_InTrailingSep:
> -      return &RawEntry.front();
> -    case PS_AtEnd:
> -      return &Path.back() + 1;
> -    }
> -    _LIBCPP_UNREACHABLE();
> -  }
> -
> -  PosPtr consumeSeparator(PosPtr P, PosPtr End) const noexcept {
> -    if (P == End || *P != '/')
> -      return nullptr;
> -    const int Inc = P < End ? 1 : -1;
> -    P += Inc;
> -    while (P != End && *P == '/')
> -      P += Inc;
> -    return P;
> -  }
> -
> -  PosPtr consumeName(PosPtr P, PosPtr End) const noexcept {
> -    if (P == End || *P == '/')
> -      return nullptr;
> -    const int Inc = P < End ? 1 : -1;
> -    P += Inc;
> -    while (P != End && *P != '/')
> -      P += Inc;
> -    return P;
> -  }
> -};
> -
> -string_view_pair separate_filename(string_view_t const & s) {
> -    if (s == "." || s == ".." || s.empty()) return string_view_pair{s,
> ""};
> -    auto pos = s.find_last_of('.');
> -    if (pos == string_view_t::npos)
> -        return string_view_pair{s, string_view_t{}};
> -    return string_view_pair{s.substr(0, pos), s.substr(pos)};
> -}
> -
> -string_view_t createView(PosPtr S, PosPtr E) noexcept {
> -  return {S, static_cast<size_t>(E - S) + 1};
> -}
> -
> -}} // namespace parser
> -
> -_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_FILESYSTEM
> -
> -using parser::string_view_t;
> -using parser::string_view_pair;
> -using parser::PathParser;
> -using parser::createView;
> -
> -///////////////////////////////////////////////////////////
> ////////////////////
> -//                            path definitions
> -///////////////////////////////////////////////////////////
> ////////////////////
> -
> -constexpr path::value_type path::preferred_separator;
> -
> -path & path::replace_extension(path const & replacement)
> -{
> -    path p = extension();
> -    if (not p.empty()) {
> -      __pn_.erase(__pn_.size() - p.native().size());
> -    }
> -    if (!replacement.empty()) {
> -        if (replacement.native()[0] != '.') {
> -            __pn_ += ".";
> -        }
> -        __pn_.append(replacement.__pn_);
> -    }
> -    return *this;
> -}
> -
> -///////////////////////////////////////////////////////////
> ////////////////////
> -// path.decompose
> -
> -string_view_t path::__root_name() const
> -{
> -    auto PP = PathParser::CreateBegin(__pn_);
> -    if (PP.State == PathParser::PS_InRootName)
> -      return *PP;
> -    return {};
> -}
> -
> -string_view_t path::__root_directory() const
> -{
> -    auto PP = PathParser::CreateBegin(__pn_);
> -    if (PP.State == PathParser::PS_InRootName)
> -      ++PP;
> -    if (PP.State == PathParser::PS_InRootDir)
> -      return *PP;
> -    return {};
> -}
> -
> -string_view_t path::__root_path_raw() const
> -{
> -    auto PP = PathParser::CreateBegin(__pn_);
> -    if (PP.State == PathParser::PS_InRootName) {
> -      auto NextCh = PP.peek();
> -      if (NextCh && *NextCh == '/') {
> -        ++PP;
> -        return createView(__pn_.data(), &PP.RawEntry.back());
> -      }
> -      return PP.RawEntry;
> -    }
> -    if (PP.State == PathParser::PS_InRootDir)
> -      return *PP;
> -    return {};
> -}
> -
> -string_view_t path::__relative_path() const
> -{
> -    auto PP = PathParser::CreateBegin(__pn_);
> -    while (PP.State <= PathParser::PS_InRootDir)
> -      ++PP;
> -    if (PP.State == PathParser::PS_AtEnd)
> -      return {};
> -    return createView(PP.RawEntry.data(), &__pn_.back());
> -}
> -
> -string_view_t path::__parent_path() const
> -{
> -    if (empty())
> -      return {};
> -    auto PP = PathParser::CreateEnd(__pn_);
> -    --PP;
> -    if (PP.RawEntry.data() == __pn_.data())
> -      return {};
> -    --PP;
> -    return createView(__pn_.data(), &PP.RawEntry.back());
> -}
> -
> -string_view_t path::__filename() const
> -{
> -    if (empty()) return {};
> -    return *(--PathParser::CreateEnd(__pn_));
> -}
> -
> -string_view_t path::__stem() const
> -{
> -    return parser::separate_filename(__filename()).first;
> -}
> -
> -string_view_t path::__extension() const
> -{
> -    return parser::separate_filename(__filename()).second;
> -}
> -
> -///////////////////////////////////////////////////////////
> /////////////////
> -// path.comparisons
> -int path::__compare(string_view_t __s) const {
> -    auto PP = PathParser::CreateBegin(__pn_);
> -    auto PP2 = PathParser::CreateBegin(__s);
> -    while (PP && PP2) {
> -        int res = (*PP).compare(*PP2);
> -        if (res != 0) return res;
> -        ++PP; ++PP2;
> -    }
> -    if (PP.State == PP2.State && PP.State == PathParser::PS_AtEnd)
> -        return 0;
> -    if (PP.State == PathParser::PS_AtEnd)
> -        return -1;
> -    return 1;
> -}
> -
> -///////////////////////////////////////////////////////////
> /////////////////
> -// path.nonmembers
> -size_t hash_value(const path& __p) noexcept {
> -  auto PP = PathParser::CreateBegin(__p.native());
> -  size_t hash_value = 0;
> -  std::hash<string_view_t> hasher;
> -  while (PP) {
> -    hash_value = __hash_combine(hash_value, hasher(*PP));
> -    ++PP;
> -  }
> -  return hash_value;
> -}
> -
> -///////////////////////////////////////////////////////////
> /////////////////
> -// path.itr
> -path::iterator path::begin() const
> -{
> -    auto PP = PathParser::CreateBegin(__pn_);
> -    iterator it;
> -    it.__path_ptr_ = this;
> -    it.__state_ = PP.State;
> -    it.__entry_ = PP.RawEntry;
> -    it.__stashed_elem_.__assign_view(*PP);
> -    return it;
> -}
> -
> -path::iterator path::end() const
> -{
> -    iterator it{};
> -    it.__state_ = PathParser::PS_AtEnd;
> -    it.__path_ptr_ = this;
> -    return it;
> -}
> -
> -path::iterator& path::iterator::__increment() {
> -  static_assert(__at_end == PathParser::PS_AtEnd, "");
> -  PathParser PP(__path_ptr_->native(), __entry_, __state_);
> -  ++PP;
> -  __state_ = PP.State;
> -  __entry_ = PP.RawEntry;
> -  __stashed_elem_.__assign_view(*PP);
> -  return *this;
> -}
> -
> -path::iterator& path::iterator::__decrement() {
> -  PathParser PP(__path_ptr_->native(), __entry_, __state_);
> -  --PP;
> -  __state_ = PP.State;
> -  __entry_ = PP.RawEntry;
> -  __stashed_elem_.__assign_view(*PP);
> -  return *this;
> -}
> -
> -_LIBCPP_END_NAMESPACE_EXPERIMENTAL_FILESYSTEM
>
> Removed: libcxx/trunk/test/libcxx/experimental/filesystem/class.
> path/path.member/path.append.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/
> libcxx/experimental/filesystem/class.path/path.
> member/path.append.pass.cpp?rev=329027&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/test/libcxx/experimental/filesystem/class.
> path/path.member/path.append.pass.cpp (original)
> +++ libcxx/trunk/test/libcxx/experimental/filesystem/class.
> path/path.member/path.append.pass.cpp (removed)
> @@ -1,70 +0,0 @@
> -//===------------------------------------------------------
> ----------------===//
> -//
> -//                     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.
> -//
> -//===------------------------------------------------------
> ----------------===//
> -
> -// UNSUPPORTED: c++98, c++03
> -
> -// <experimental/filesystem>
> -
> -// class path
> -
> -// path& operator/=(path const&)
> -// path operator/(path const&, path const&)
> -
> -
> -#define _LIBCPP_DEBUG 0
> -#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : (void)::AssertCount++)
> -int AssertCount = 0;
> -
> -#include <experimental/filesystem>
> -#include <type_traits>
> -#include <string_view>
> -#include <cassert>
> -
> -#include "test_macros.h"
> -#include "test_iterators.h"
> -#include "count_new.hpp"
> -#include "filesystem_test_helper.hpp"
> -
> -namespace fs = std::experimental::filesystem;
> -
> -int main()
> -{
> -  using namespace fs;
> -  {
> -    path lhs("//foo");
> -    path rhs("/bar");
> -    assert(AssertCount == 0);
> -    lhs /= rhs;
> -    assert(AssertCount == 0);
> -  }
> -  {
> -    path lhs("//foo");
> -    path rhs("/bar");
> -    assert(AssertCount == 0);
> -    (void)(lhs / rhs);
> -    assert(AssertCount == 0);
> -  }
> -  {
> -    path lhs("//foo");
> -    path rhs("//bar");
> -    assert(AssertCount == 0);
> -    lhs /= rhs;
> -    assert(AssertCount == 1);
> -    AssertCount = 0;
> -  }
> -  {
> -    path lhs("//foo");
> -    path rhs("//bar");
> -    assert(AssertCount == 0);
> -    (void)(lhs / rhs);
> -    assert(AssertCount == 1);
> -  }
> -  // FIXME The same error is not diagnosed for the append(Source) and
> -  // append(It, It) overloads.
> -}
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.itr/iterator.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.itr/iterator.pass.
> cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.itr/iterator.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.itr/iterator.pass.cpp Mon Apr  2 16:03:41 2018
> @@ -83,14 +83,14 @@ void checkBeginEndBasic() {
>    }
>    {
>      path p("//root_name//first_dir////second_dir");
> -    const path expect[] = {"//root_name", "/", "first_dir", "second_dir"};
> +    const path expect[] = {"/", "root_name", "first_dir", "second_dir"};
>      assert(checkCollectionsEqual(p.begin(), p.end(), std::begin(expect),
> std::end(expect)));
>      assert(checkCollectionsEqualBackwards(p.begin(), p.end(),
> std::begin(expect), std::end(expect)));
>
>    }
>    {
>      path p("////foo/bar/baz///");
> -    const path expect[] = {"/", "foo", "bar", "baz", "."};
> +    const path expect[] = {"/", "foo", "bar", "baz", ""};
>      assert(checkCollectionsEqual(p.begin(), p.end(), std::begin(expect),
> std::end(expect)));
>      assert(checkCollectionsEqualBackwards(p.begin(), p.end(),
> std::begin(expect), std::end(expect)));
>
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.append.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.member/path.append.
> pass.cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.append.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.append.pass.cpp Mon Apr  2 16:03:41 2018
> @@ -31,6 +31,7 @@
>  #include "test_iterators.h"
>  #include "count_new.hpp"
>  #include "filesystem_test_helper.hpp"
> +#include "verbose_assert.h"
>
>
>  struct AppendOperatorTestcase {
> @@ -45,13 +46,22 @@ const AppendOperatorTestcase Cases[] =
>          {S(""),     S(""),      S("")}
>        , {S("p1"),   S("p2"),    S("p1/p2")}
>        , {S("p1/"),  S("p2"),    S("p1/p2")}
> -      , {S("p1"),   S("/p2"),   S("p1/p2")}
> -      , {S("p1/"),  S("/p2"),   S("p1//p2")}
> +      , {S("p1"),   S("/p2"),   S("/p2")}
> +      , {S("p1/"),  S("/p2"),   S("/p2")}
>        , {S("p1"),   S("\\p2"),  S("p1/\\p2")}
>        , {S("p1\\"), S("p2"),  S("p1\\/p2")}
>        , {S("p1\\"), S("\\p2"),  S("p1\\/\\p2")}
> -      , {S("p1"),   S(""),      S("p1")}
>        , {S(""),     S("p2"),    S("p2")}
> +      , {S("/p1"),  S("p2"),    S("/p1/p2")}
> +      , {S("/p1"),  S("/p2"),    S("/p2")}
> +      , {S("/p1/p3"),  S("p2"),    S("/p1/p3/p2")}
> +      , {S("/p1/p3/"),  S("p2"),    S("/p1/p3/p2")}
> +      , {S("/p1/"),  S("p2"),    S("/p1/p2")}
> +      , {S("/p1/p3/"),  S("/p2/p4"),    S("/p2/p4")}
> +      , {S("/"),    S(""),      S("/")}
> +      , {S("/p1"), S("/p2/"), S("/p2/")}
> +      , {S("p1"),   S(""),      S("p1/")}
> +      , {S("p1/"),  S(""),      S("p1/")}
>      };
>
>
> @@ -59,7 +69,8 @@ const AppendOperatorTestcase LongLHSCase
>      {
>          {S("p1"),   S("p2"),    S("p1/p2")}
>        , {S("p1/"),  S("p2"),    S("p1/p2")}
> -      , {S("p1"),   S("/p2"),   S("p1/p2")}
> +      , {S("p1"),   S("/p2"),   S("/p2")}
> +      , {S("/p1"),  S("p2"),    S("/p1/p2")}
>      };
>  #undef S
>
> @@ -98,7 +109,7 @@ void doAppendSourceAllocTest(AppendOpera
>        DisableAllocationGuard g;
>        LHS /= RHS;
>      }
> -    assert(LHS == E);
> +    ASSERT_PRED(PathEq, LHS , E);
>    }
>    // basic_string_view
>    {
> @@ -108,7 +119,7 @@ void doAppendSourceAllocTest(AppendOpera
>        DisableAllocationGuard g;
>        LHS /= RHS;
>      }
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>    }
>    // CharT*
>    {
> @@ -118,7 +129,7 @@ void doAppendSourceAllocTest(AppendOpera
>        DisableAllocationGuard g;
>        LHS /= RHS;
>      }
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>    }
>    {
>      path LHS(L); PathReserve(LHS, ReserveSize);
> @@ -127,7 +138,7 @@ void doAppendSourceAllocTest(AppendOpera
>        DisableAllocationGuard g;
>        LHS.append(RHS, StrEnd(RHS));
>      }
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>    }
>    // input iterator - For non-native char types, appends needs to copy the
>    // iterator range into a contiguous block of memory before it can
> perform the
> @@ -143,7 +154,7 @@ void doAppendSourceAllocTest(AppendOpera
>        if (DisableAllocations) g.requireExactly(0);
>        LHS /= RHS;
>      }
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>    }
>    {
>      path LHS(L); PathReserve(LHS, ReserveSize);
> @@ -154,7 +165,7 @@ void doAppendSourceAllocTest(AppendOpera
>        if (DisableAllocations) g.requireExactly(0);
>        LHS.append(RHS, REnd);
>      }
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>    }
>  }
>
> @@ -171,17 +182,18 @@ void doAppendSourceTest(AppendOperatorTe
>    const Ptr E = TC.expect;
>    // basic_string
>    {
> -    path LHS(L);
> +    path Result(L);
>      Str RHS(R);
> -    path& Ref = (LHS /= RHS);
> -    assert(LHS == E);
> -    assert(&Ref == &LHS);
> +    path& Ref = (Result /= RHS);
> +    ASSERT_EQ(Result, E)
> +        << DISPLAY(L) << DISPLAY(R);
> +    assert(&Ref == &Result);
>    }
>    {
>      path LHS(L);
>      Str RHS(R);
>      path& Ref = LHS.append(RHS);
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>      assert(&Ref == &LHS);
>    }
>    // basic_string_view
> @@ -189,14 +201,14 @@ void doAppendSourceTest(AppendOperatorTe
>      path LHS(L);
>      StrView RHS(R);
>      path& Ref = (LHS /= RHS);
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>      assert(&Ref == &LHS);
>    }
>    {
>      path LHS(L);
>      StrView RHS(R);
>      path& Ref = LHS.append(RHS);
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>      assert(&Ref == &LHS);
>    }
>    // Char*
> @@ -204,21 +216,22 @@ void doAppendSourceTest(AppendOperatorTe
>      path LHS(L);
>      Str RHS(R);
>      path& Ref = (LHS /= RHS);
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>      assert(&Ref == &LHS);
>    }
>    {
>      path LHS(L);
>      Ptr RHS(R);
>      path& Ref = LHS.append(RHS);
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>      assert(&Ref == &LHS);
>    }
>    {
>      path LHS(L);
>      Ptr RHS(R);
>      path& Ref = LHS.append(RHS, StrEnd(RHS));
> -    assert(LHS == E);
> +    ASSERT_PRED(PathEq, LHS, E)
> +        << DISPLAY(L) << DISPLAY(R);
>      assert(&Ref == &LHS);
>    }
>    // iterators
> @@ -226,13 +239,13 @@ void doAppendSourceTest(AppendOperatorTe
>      path LHS(L);
>      InputIter RHS(R);
>      path& Ref = (LHS /= RHS);
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>      assert(&Ref == &LHS);
>    }
>    {
>      path LHS(L); InputIter RHS(R);
>      path& Ref = LHS.append(RHS);
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>      assert(&Ref == &LHS);
>    }
>    {
> @@ -240,7 +253,7 @@ void doAppendSourceTest(AppendOperatorTe
>      InputIter RHS(R);
>      InputIter REnd(StrEnd(R));
>      path& Ref = LHS.append(RHS, REnd);
> -    assert(LHS == E);
> +    assert(PathEq(LHS, E));
>      assert(&Ref == &LHS);
>    }
>  }
> @@ -304,11 +317,14 @@ int main()
>    using namespace fs;
>    for (auto const & TC : Cases) {
>      {
> -      path LHS((const char*)TC.lhs);
> -      path RHS((const char*)TC.rhs);
> -      path& Ref = (LHS /= RHS);
> -      assert(LHS == (const char*)TC.expect);
> -      assert(&Ref == &LHS);
> +      const char* LHS_In = TC.lhs;
> +      const char* RHS_In = TC.rhs;
> +      path LHS(LHS_In);
> +      path RHS(RHS_In);
> +      path& Res = (LHS /= RHS);
> +      ASSERT_PRED(PathEq, Res, (const char*)TC.expect)
> +          << DISPLAY(LHS_In) << DISPLAY(RHS_In);
> +      assert(&Res == &LHS);
>      }
>      doAppendSourceTest<char>    (TC);
>      doAppendSourceTest<wchar_t> (TC);
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.compare.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.member/path.compare.
> pass.cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.compare.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.compare.pass.cpp Mon Apr  2 16:03:41 2018
> @@ -26,6 +26,7 @@
>  //
>  // size_t hash_value(path const&) noexcept;
>
> +
>  #include "filesystem_include.hpp"
>  #include <type_traits>
>  #include <vector>
> @@ -35,7 +36,7 @@
>  #include "test_iterators.h"
>  #include "count_new.hpp"
>  #include "filesystem_test_helper.hpp"
> -
> +#include "verbose_assert.h"
>
>  struct PathCompareTest {
>    const char* LHS;
> @@ -57,8 +58,9 @@ const PathCompareTest CompareTestCases[]
>      {"a/b/c", "b/a/c", -1},
>      {"a/b", "a/b/c", -1},
>      {"a/b/c", "a/b", 1},
> -    {"a/b/", "a/b/.", 0},
> -    {"a/b//////", "a/b/////.", 0},
> +    {"a/b/", "a/b/.", -1},
> +    {"a/b/", "a/b",    1},
> +    {"a/b//////", "a/b/////.", -1},
>      {"a/.././b", "a///..//.////b", 0},
>      {"//foo//bar///baz////", "//foo/bar/baz/", 0}, // duplicate separators
>      {"///foo/bar", "/foo/bar", 0}, // "///" is not a root directory
> @@ -94,8 +96,13 @@ int main()
>        int ret2 = normalize_ret(p1.compare(R));
>        int ret3 = normalize_ret(p1.compare(TC.RHS));
>        int ret4 = normalize_ret(p1.compare(RV));
> -      assert(ret1 == ret2 && ret1 == ret3 && ret1 == ret4);
> -      assert(ret1 == E);
> +
> +      g.release();
> +      ASSERT_EQ(ret1, ret2);
> +      ASSERT_EQ(ret1, ret3);
> +      ASSERT_EQ(ret1, ret4);
> +      ASSERT_EQ(ret1, E)
> +          << DISPLAY(TC.LHS) << DISPLAY(TC.RHS);
>
>        // check signatures
>        ASSERT_NOEXCEPT(p1.compare(p2));
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.decompose/empty.fail.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.member/path.
> decompose/empty.fail.cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.decompose/empty.fail.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.decompose/empty.fail.cpp Mon Apr  2 16:03:41 2018
> @@ -18,6 +18,7 @@
>  // UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7,
> clang-3.8
>
>  #include "filesystem_include.hpp"
> +
>  #include "test_macros.h"
>
>  int main ()
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.decompose/path.decompose.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.member/path.
> decompose/path.decompose.pass.cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.decompose/path.decompose.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.decompose/path.decompose.pass.cpp Mon Apr  2
> 16:03:41 2018
> @@ -53,6 +53,14 @@
>  #include "test_iterators.h"
>  #include "count_new.hpp"
>  #include "filesystem_test_helper.hpp"
> +#include "assert_checkpoint.h"
> +#include "verbose_assert.h"
> +
> +struct ComparePathExact {
> +  bool operator()(std::string const& LHS, std::string const& RHS) const {
> +    return LHS == RHS;
> +  }
> +};
>
>  struct PathDecomposeTestcase
>  {
> @@ -72,80 +80,89 @@ const PathDecomposeTestcase PathTestCase
>      , {".", {"."}, "", "", "", ".", "", "."}
>      , {"..", {".."}, "", "", "", "..", "", ".."}
>      , {"foo", {"foo"}, "", "", "", "foo", "", "foo"}
> -    , {"/", {"/"}, "/", "", "/", "", "", "/"}
> +    , {"/", {"/"}, "/", "", "/", "", "/", ""}
>      , {"/foo", {"/", "foo"}, "/", "", "/", "foo", "/", "foo"}
> -    , {"foo/", {"foo", "."}, "", "", "", "foo/", "foo", "."}
> -    , {"/foo/", {"/", "foo", "."}, "/", "", "/", "foo/", "/foo", "."}
> +    , {"foo/", {"foo", ""}, "", "", "", "foo/", "foo", ""}
> +    , {"/foo/", {"/", "foo", ""}, "/", "", "/", "foo/", "/foo", ""}
>      , {"foo/bar", {"foo","bar"}, "",  "", "",  "foo/bar", "foo", "bar"}
>      , {"/foo//bar", {"/","foo","bar"}, "/", "", "/", "foo/bar", "/foo",
> "bar"}
> -    , {"//net", {"//net"}, "//net", "//net", "", "", "", "//net"}
> -    , {"//net/foo", {"//net", "/", "foo"}, "//net/", "//net", "/", "foo",
> "//net/", "foo"}
> -    , {"///foo///", {"/", "foo", "."}, "/", "", "/", "foo///", "///foo",
> "."}
> +    , {"//net", {"/", "net"}, "/", "", "/", "net", "/", "net"}
> +    , {"//net/foo", {"/", "net", "foo"}, "/", "", "/", "net/foo", "/net",
> "foo"}
> +    , {"///foo///", {"/", "foo", ""}, "/", "", "/", "foo///", "///foo",
> ""}
>      , {"///foo///bar", {"/", "foo", "bar"}, "/", "", "/", "foo///bar",
> "///foo", "bar"}
>      , {"/.", {"/", "."}, "/", "", "/", ".", "/", "."}
> -    , {"./", {".", "."}, "", "", "", "./", ".", "."}
> +    , {"./", {".", ""}, "", "", "", "./", ".", ""}
>      , {"/..", {"/", ".."}, "/", "", "/", "..", "/", ".."}
> -    , {"../", {"..", "."}, "", "", "", "../", "..", "."}
> +    , {"../", {"..", ""}, "", "", "", "../", "..", ""}
>      , {"foo/.", {"foo", "."}, "", "", "", "foo/.", "foo", "."}
>      , {"foo/..", {"foo", ".."}, "", "", "", "foo/..", "foo", ".."}
> -    , {"foo/./", {"foo", ".", "."}, "", "", "", "foo/./", "foo/.", "."}
> +    , {"foo/./", {"foo", ".", ""}, "", "", "", "foo/./", "foo/.", ""}
>      , {"foo/./bar", {"foo", ".", "bar"}, "", "", "", "foo/./bar",
> "foo/.", "bar"}
> -    , {"foo/../", {"foo", "..", "."}, "", "", "", "foo/../", "foo/..",
> "."}
> +    , {"foo/../", {"foo", "..", ""}, "", "", "", "foo/../", "foo/..", ""}
>      , {"foo/../bar", {"foo", "..", "bar"}, "", "", "", "foo/../bar",
> "foo/..", "bar"}
>      , {"c:", {"c:"}, "", "", "", "c:", "", "c:"}
> -    , {"c:/", {"c:", "."}, "", "", "", "c:/", "c:", "."}
> +    , {"c:/", {"c:", ""}, "", "", "", "c:/", "c:", ""}
>      , {"c:foo", {"c:foo"}, "", "", "", "c:foo", "", "c:foo"}
>      , {"c:/foo", {"c:", "foo"}, "", "", "", "c:/foo", "c:", "foo"}
> -    , {"c:foo/", {"c:foo", "."}, "", "", "", "c:foo/", "c:foo", "."}
> -    , {"c:/foo/", {"c:", "foo", "."}, "", "", "", "c:/foo/",  "c:/foo",
> "."}
> +    , {"c:foo/", {"c:foo", ""}, "", "", "", "c:foo/", "c:foo", ""}
> +    , {"c:/foo/", {"c:", "foo", ""}, "", "", "", "c:/foo/",  "c:/foo", ""}
>      , {"c:/foo/bar", {"c:", "foo", "bar"}, "", "", "", "c:/foo/bar",
> "c:/foo", "bar"}
>      , {"prn:", {"prn:"}, "", "", "", "prn:", "", "prn:"}
>      , {"c:\\", {"c:\\"}, "", "", "", "c:\\", "", "c:\\"}
>      , {"c:\\foo", {"c:\\foo"}, "", "", "", "c:\\foo", "", "c:\\foo"}
>      , {"c:foo\\", {"c:foo\\"}, "", "", "", "c:foo\\", "", "c:foo\\"}
>      , {"c:\\foo\\", {"c:\\foo\\"}, "", "", "", "c:\\foo\\", "",
> "c:\\foo\\"}
> -    , {"c:\\foo/",  {"c:\\foo", "."}, "", "", "", "c:\\foo/", "c:\\foo",
> "."}
> +    , {"c:\\foo/",  {"c:\\foo", ""}, "", "", "", "c:\\foo/", "c:\\foo",
> ""}
>      , {"c:/foo\\bar", {"c:", "foo\\bar"}, "", "", "", "c:/foo\\bar",
> "c:", "foo\\bar"}
> -    , {"//", {"//"}, "//", "//", "", "", "", "//"}
> +    , {"//", {"/"}, "/", "", "/", "", "/", ""}
>    };
>
>  void decompPathTest()
>  {
>    using namespace fs;
>    for (auto const & TC : PathTestCases) {
> -    path p(TC.raw);
> -    assert(p == TC.raw);
> -
> -    assert(p.root_path() == TC.root_path);
> -    assert(p.has_root_path() !=  TC.root_path.empty());
> -
> -    assert(p.root_name() == TC.root_name);
> -    assert(p.has_root_name() !=  TC.root_name.empty());
> -
> -    assert(p.root_directory() == TC.root_directory);
> -    assert(p.has_root_directory() !=  TC.root_directory.empty());
> -
> -    assert(p.relative_path() == TC.relative_path);
> -    assert(p.has_relative_path() !=  TC.relative_path.empty());
> -
> -    assert(p.parent_path() == TC.parent_path);
> -    assert(p.has_parent_path() !=  TC.parent_path.empty());
> -
> -    assert(p.filename() == TC.filename);
> -    assert(p.has_filename() !=  TC.filename.empty());
> -
> -    assert(p.is_absolute() == p.has_root_directory());
> -    assert(p.is_relative() !=  p.is_absolute());
> -
> -    assert(checkCollectionsEqual(p.begin(), p.end(),
> -                                 TC.elements.begin(), TC.elements.end()));
> +    CHECKPOINT(TC.raw.c_str());
> +    fs::path p(TC.raw);
> +    ASSERT(p == TC.raw);
> +
> +    ASSERT_EQ(p.root_path(), TC.root_path);
> +    ASSERT_NEQ(p.has_root_path(), TC.root_path.empty());
> +
> +    ASSERT(p.root_name().native().empty())
> +        << DISPLAY(p.root_name());
> +    ASSERT_EQ(p.root_name(),TC.root_name);
> +    ASSERT_NEQ(p.has_root_name(), TC.root_name.empty());
> +
> +    ASSERT_EQ(p.root_directory(), TC.root_directory);
> +    ASSERT_NEQ(p.has_root_directory(), TC.root_directory.empty());
> +
> +    ASSERT_EQ(p.relative_path(), TC.relative_path);
> +    ASSERT_NEQ(p.has_relative_path(), TC.relative_path.empty());
> +
> +    ASSERT_EQ(p.parent_path(), TC.parent_path);
> +    ASSERT_NEQ(p.has_parent_path(), TC.parent_path.empty());
> +
> +    ASSERT_EQ(p.filename(), TC.filename);
> +    ASSERT_NEQ(p.has_filename(), TC.filename.empty());
> +
> +    ASSERT_EQ(p.is_absolute(), p.has_root_directory());
> +    ASSERT_NEQ(p.is_relative(), p.is_absolute());
> +    if (p.empty())
> +      ASSERT(p.is_relative());
> +
> +    ASSERT_COLLECTION_EQ_COMP(
> +        p.begin(), p.end(),
> +        TC.elements.begin(), TC.elements.end(),
> +        ComparePathExact()
> +    );
>      // check backwards
>
>      std::vector<fs::path> Parts;
>      for (auto it = p.end(); it != p.begin(); )
>        Parts.push_back(*--it);
> -    assert(checkCollectionsEqual(Parts.begin(), Parts.end(),
> -                                 TC.elements.rbegin(),
> TC.elements.rend()));
> +    ASSERT_COLLECTION_EQ_COMP(Parts.begin(), Parts.end(),
> +                                 TC.elements.rbegin(), TC.elements.rend(),
> +                              ComparePathExact());
>    }
>  }
>
> @@ -163,10 +180,12 @@ const FilenameDecompTestcase FilenameTes
>      {"", "", "", ""}
>    , {".", ".", ".", ""}
>    , {"..", "..", "..", ""}
> -  , {"/", "/", "/", ""}
> +  , {"/", "", "", ""}
>    , {"foo", "foo", "foo", ""}
>    , {"/foo/bar.txt", "bar.txt", "bar", ".txt"}
>    , {"foo..txt", "foo..txt", "foo.", ".txt"}
> +  , {".profile", ".profile", ".profile", ""}
> +  , {".profile.txt", ".profile.txt", ".profile", ".txt"}
>  };
>
>
> @@ -174,18 +193,19 @@ void decompFilenameTest()
>  {
>    using namespace fs;
>    for (auto const & TC : FilenameTestCases) {
> -    path p(TC.raw);
> -    assert(p == TC.raw);
> +    CHECKPOINT(TC.raw.c_str());
> +    fs::path p(TC.raw);
> +    ASSERT_EQ(p, TC.raw);
>      ASSERT_NOEXCEPT(p.empty());
>
> -    assert(p.filename() == TC.filename);
> -    assert(p.has_filename() != TC.filename.empty());
> +    ASSERT_EQ(p.filename(), TC.filename);
> +    ASSERT_NEQ(p.has_filename(), TC.filename.empty());
>
> -    assert(p.stem() == TC.stem);
> -    assert(p.has_stem() != TC.stem.empty());
> +    ASSERT_EQ(p.stem(), TC.stem);
> +    ASSERT_NEQ(p.has_stem(), TC.stem.empty());
>
> -    assert(p.extension() == TC.extension);
> -    assert(p.has_extension() != TC.extension.empty());
> +    ASSERT_EQ(p.extension(), TC.extension);
> +    ASSERT_NEQ(p.has_extension(), TC.extension.empty());
>    }
>  }
>
>
> Added: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.gen/lexically_normal.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.member/path.gen/
> lexically_normal.pass.cpp?rev=329028&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.gen/lexically_normal.pass.cpp (added)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.gen/lexically_normal.pass.cpp Mon Apr  2 16:03:41
> 2018
> @@ -0,0 +1,142 @@
> +//===------------------------------------------------------
> ----------------===//
> +//
> +//                     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.
> +//
> +//===------------------------------------------------------
> ----------------===//
> +
> +// UNSUPPORTED: c++98, c++03
> +
> +// <experimental/filesystem>
> +
> +// class path
> +
> +// path lexically_normal() const;
> +
> +#include "filesystem_include.hpp"
> +#include <type_traits>
> +#include <vector>
> +#include <iostream>
> +#include <cassert>
> +
> +#include "test_macros.h"
> +#include "test_iterators.h"
> +#include "count_new.hpp"
> +#include "filesystem_test_helper.hpp"
> +
> +
> +int main() {
> +  // clang-format off
> +  struct {
> +    std::string input;
> +    std::string expect;
> +  } TestCases[] = {
> +      {"", ""},
> +      {"/a/b/c", "/a/b/c"},
> +      {"/a/b//c", "/a/b/c"},
> +      {"foo/./bar/..", "foo/"},
> +      {"foo/.///bar/../", "foo/"},
> +      {"/a/b/", "/a/b/"},
> +      {"a/b", "a/b"},
> +      {"a/b/.", "a/b/"},
> +      {"a/b/./", "a/b/"},
> +      {"a/..", "."},
> +      {".", "."},
> +      {"./", "."},
> +      {"./.", "."},
> +      {"./..", ".."},
> +      {"..", ".."},
> +      {"../..", "../.."},
> +      {"/../", "/"},
> +      {"/../..", "/"},
> +      {"/../../", "/"},
> +      {"..", ".."},
> +      {"../", ".."},
> +      {"/a/b/c/../", "/a/b/"},
> +      {"/a/b/./", "/a/b/"},
> +      {"/a/b/c/../d", "/a/b/d"},
> +      {"/a/b/c/../d/", "/a/b/d/"},
> +      {"//a/", "/a/"},
> +      {"//a/b/", "/a/b/"},
> +      {"//a/b/.", "/a/b/"},
> +      {"//a/..", "/"},
> +      ///===------------------------------------------------------
> ---------===//
> +      /// Tests specifically for the clauses under [fs.path.generic]p6
> +      ///===------------------------------------------------------
> ---------===//
> +      // p1: If the path is empty, stop.
> +      {"", ""},
> +      // p2: Replace each slash character in the root-name with a
> preferred
> +      // separator.
> +      {"NO_ROOT_NAME_ON_LINUX", "NO_ROOT_NAME_ON_LINUX"},
> +      // p3: Replace each directory-separator with a preferred-separator.
> +      // [ Note: The generic pathname grammar ([fs.path.generic])
> defines
> +      //   directory-separator as one or more slashes and
> preferred-separators.
> +      //   — end note ]
> +      {"/", "/"},
> +      {"//", "/"},
> +      {"///", "/"},
> +      {"a/b", "a/b"},
> +      {"a//b", "a/b"},
> +      {"a///b", "a/b"},
> +      {"a/b/", "a/b/"},
> +      {"a/b//", "a/b/"},
> +      {"a/b///", "a/b/"},
> +      {"///a////b//////", "/a/b/"},
> +      // p4: Remove each dot filename and any immediately following
> directory
> +      // separators
> +      {"foo/.", "foo/"},
> +      {"foo/./bar/.", "foo/bar/"},
> +      {"./foo/././bar/./", "foo/bar/"},
> +      {".///foo//.////./bar/.///", "foo/bar/"},
> +      // p5: As long as any appear, remove a non-dot-dot filename
> immediately
> +      // followed by a directory-separator and a dot-dot filename, along
> with
> +      // any immediately following directory separator.
> +      {"foo/..", "."},
> +      {"foo/../", "."},
> +      {"foo/bar/..", "foo/"},
> +      {"foo/bar/../", "foo/"},
> +      {"foo/bar/../..", "."},
> +      {"foo/bar/../../", "."},
> +      {"foo/bar/baz/../..", "foo/"},
> +      {"foo/bar/baz/../../", "foo/"},
> +      {"foo/bar/./..", "foo/"},
> +      {"foo/bar/./../", "foo/"},
> +      // p6: If there is a root-directory, remove all dot-dot filenames
> and any
> +      // directory-separators immediately following them. [ Note: These
> dot-dot
> +      // filenames attempt to refer to nonexistent parent directories.
> — end note ]
> +      {"/..", "/"},
> +      {"/../", "/"},
> +      {"/foo/../..", "/"},
> +      {"/../foo", "/foo"},
> +      {"/../foo/../..", "/"},
> +      // p7: If the last filename is dot-dot, remove any trailing
> +      // directory-separator.
> +      {"../", ".."},
> +      {"../../", "../.."},
> +      {"foo/../bar/../..///", ".."},
> +      {"foo/../bar/..//..///../", "../.."},
> +      // p8: If the path is empty, add a dot
> +      {".", "."},
> +      {"./", "."},
> +      {"foo/..", "."}
> +  };
> +  // clang-format on
> +  int ID = 0;
> +  bool Failed = false;
> +  for (auto& TC : TestCases) {
> +    ++ID;
> +    fs::path p(TC.input);
> +    const fs::path output = p.lexically_normal();
> +    if (!PathEq(output, TC.expect)) {
> +      Failed = true;
> +      std::cerr << "TEST CASE #" << ID << " FAILED: \n";
> +      std::cerr << "  Input: '" << TC.input << "'\n";
> +      std::cerr << "  Expected: '" << TC.expect << "'\n";
> +      std::cerr << "  Output: '" << output.native() << "'";
> +      std::cerr << std::endl;
> +    }
> +  }
> +  return Failed;
> +}
>
> Added: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.gen/lexically_relative_and_proximate.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.member/path.gen/
> lexically_relative_and_proximate.pass.cpp?rev=329028&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.gen/lexically_relative_and_proximate.pass.cpp
> (added)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.gen/lexically_relative_and_proximate.pass.cpp Mon
> Apr  2 16:03:41 2018
> @@ -0,0 +1,89 @@
> +//===------------------------------------------------------
> ----------------===//
> +//
> +//                     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.
> +//
> +//===------------------------------------------------------
> ----------------===//
> +
> +// UNSUPPORTED: c++98, c++03
> +
> +// <experimental/filesystem>
> +
> +// class path
> +
> +// path lexically_relative(const path& p) const;
> +// path lexically_proximate(const path& p) const;
> +
> +#include "filesystem_include.hpp"
> +#include <type_traits>
> +#include <vector>
> +#include <iostream>
> +#include <cassert>
> +
> +#include "test_macros.h"
> +#include "test_iterators.h"
> +#include "count_new.hpp"
> +#include "filesystem_test_helper.hpp"
> +
> +
> +int main() {
> +  // clang-format off
> +  struct {
> +    std::string input;
> +    std::string base;
> +    std::string expect;
> +  } TestCases[] = {
> +      {"", "", "."},
> +      {"/", "a", ""},
> +      {"a", "/", ""},
> +      {"//net", "a", ""},
> +      {"a", "//net", ""},
> +      {"//net/", "//net", ""},
> +      {"//net", "//net/", ".."},
> +      {"//base", "a", ""},
> +      {"a", "a", "."},
> +      {"a/b", "a/b", "."},
> +      {"a/b/c/", "a/b/c/", "."},
> +      {"//net", "//net", "."},
> +      {"//net/", "//net/", "."},
> +      {"//net/a/b", "//net/a/b", "."},
> +      {"/a/d", "/a/b/c", "../../d"},
> +      {"/a/b/c", "/a/d", "../b/c"},
> +      {"a/b/c", "a", "b/c"},
> +      {"a/b/c", "a/b/c/x/y", "../.."},
> +      {"a/b/c", "a/b/c", "."},
> +      {"a/b", "c/d", "../../a/b"}
> +  };
> +  // clang-format on
> +  int ID = 0;
> +  bool Failed = false;
> +  for (auto& TC : TestCases) {
> +    ++ID;
> +    const fs::path p(TC.input);
> +    const fs::path output = p.lexically_relative(TC.base);
> +    auto ReportErr = [&](const char* Testing, fs::path const& Output,
> +                                              fs::path const& Expected) {
> +      Failed = true;
> +      std::cerr << "TEST CASE #" << ID << " FAILED: \n";
> +      std::cerr << "  Testing: " << Testing << "\n";
> +      std::cerr << "  Input: '" << TC.input << "'\n";
> +      std::cerr << "  Base: '" << TC.base << "'\n";
> +      std::cerr << "  Expected: '" << Expected << "'\n";
> +      std::cerr << "  Output: '" << Output.native() << "'";
> +      std::cerr << std::endl;
> +    };
> +    if (!PathEq(output, TC.expect))
> +      ReportErr("path::lexically_relative", output, TC.expect);
> +    const fs::path proximate_output = p.lexically_proximate(TC.base);
> +    // [path.gen] lexically_proximate
> +    // Returns: If the value of lexically_relative(base) is not an empty
> path,
> +    // return it.Otherwise return *this.
> +    const fs::path proximate_expected = output.native().empty() ? p
> +        : output;
> +    if (!PathEq(proximate_expected, proximate_output))
> +      ReportErr("path::lexically_proximate", proximate_output,
> proximate_expected);
> +  }
> +  return Failed;
> +}
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.generic.obs/generic_string_alloc.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.member/path.generic.
> obs/generic_string_alloc.pass.cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.generic.obs/generic_string_alloc.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.generic.obs/generic_string_alloc.pass.cpp Mon Apr
> 2 16:03:41 2018
> @@ -28,7 +28,6 @@
>  #include "min_allocator.h"
>  #include "filesystem_test_helper.hpp"
>
> -
>  MultiStringType longString = MKSTR("abcdefghijklmnopqrstuvwxyzABCD
> EFGHIJKLMNOPQRSTUVWXYZ/123456789/abcdefghijklmnopqrstuvwxyzABCD
> EFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKL
> MNOPQRSTUVWXYZ");
>
>
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.generic.obs/named_overloads.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.member/path.generic.
> obs/named_overloads.pass.cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.generic.obs/named_overloads.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.generic.obs/named_overloads.pass.cpp Mon Apr  2
> 16:03:41 2018
> @@ -30,7 +30,6 @@
>  #include "min_allocator.h"
>  #include "filesystem_test_helper.hpp"
>
> -
>  MultiStringType longString = MKSTR("abcdefghijklmnopqrstuvwxyzABCD
> EFGHIJKLMNOPQRSTUVWXYZ/123456789/abcdefghijklmnopqrstuvwxyzABCD
> EFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKL
> MNOPQRSTUVWXYZ");
>
>  int main()
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.modifiers/remove_filename.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.member/path.
> modifiers/remove_filename.pass.cpp?rev=329028&r1=329027&
> r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.modifiers/remove_filename.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.modifiers/remove_filename.pass.cpp Mon Apr  2
> 16:03:41 2018
> @@ -23,7 +23,7 @@
>  #include "test_iterators.h"
>  #include "count_new.hpp"
>  #include "filesystem_test_helper.hpp"
> -
> +#include "verbose_assert.h"
>
>  struct RemoveFilenameTestcase {
>    const char* value;
> @@ -33,27 +33,29 @@ struct RemoveFilenameTestcase {
>  const RemoveFilenameTestcase TestCases[] =
>    {
>        {"", ""}
> -    , {"/", ""}
> -    , {"//", ""}
> -    , {"///", ""}
> +    , {"/", "/"}
> +    , {"//", "//"}
> +    , {"///", "///"}
>      , {"\\", ""}
>      , {".", ""}
>      , {"..", ""}
>      , {"/foo", "/"}
> -    , {"//foo", ""}
> -    , {"//foo/", ""}
> -    , {"//foo///", ""}
> -    , {"///foo", "/"}
> -    , {"///foo/", "///foo"}
> -    , {"/foo/", "/foo"}
> -    , {"/foo/.", "/foo"}
> -    , {"/foo/..", "/foo"}
> -    , {"/foo/////", "/foo"}
> +    , {"foo/bar", "foo/"}
> +    , {"foo/", "foo/"}
> +    , {"//foo", "//"}
> +    , {"//foo/", "//foo/"}
> +    , {"//foo///", "//foo///"}
> +    , {"///foo", "///"}
> +    , {"///foo/", "///foo/"}
> +    , {"/foo/", "/foo/"}
> +    , {"/foo/.", "/foo/"}
> +    , {"/foo/..", "/foo/"}
> +    , {"/foo/////", "/foo/////"}
>      , {"/foo\\\\", "/"}
> -    , {"/foo//\\/", "/foo//\\"}
> -    , {"///foo", "/"}
> +    , {"/foo//\\/", "/foo//\\/"}
> +    , {"///foo", "///"}
>      , {"file.txt", ""}
> -    , {"bar/../baz/./file.txt", "bar/../baz/."}
> +    , {"bar/../baz/./file.txt", "bar/../baz/./"}
>    };
>
>  int main()
> @@ -64,16 +66,8 @@ int main()
>      path p(p_orig);
>      assert(p == TC.value);
>      path& Ref = (p.remove_filename());
> -    assert(p == TC.expect);
> +    ASSERT_EQ(p, TC.expect) << DISPLAY(p_orig);
>      assert(&Ref == &p);
> -    {
> -      const path parentp = p_orig.parent_path();
> -      if (parentp == p_orig.root_name()) {
> -
> -        assert(p.empty());
> -      } else {
> -        assert(p == parentp);
> -      }
> -    }
> +    assert(!p.has_filename());
>    }
>  }
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.modifiers/replace_filename.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/class.path/path.member/path.
> modifiers/replace_filename.pass.cpp?rev=329028&r1=329027&
> r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.modifiers/replace_filename.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/class.
> path/path.member/path.modifiers/replace_filename.pass.cpp Mon Apr  2
> 16:03:41 2018
> @@ -23,7 +23,8 @@
>  #include "test_iterators.h"
>  #include "count_new.hpp"
>  #include "filesystem_test_helper.hpp"
> -
> +#include "assert_checkpoint.h"
> +#include "verbose_assert.h"
>
>  struct ReplaceFilenameTestcase {
>    const char* value;
> @@ -36,9 +37,9 @@ const ReplaceFilenameTestcase TestCases[
>        {"/foo", "/bar", "bar"}
>      , {"/foo", "/", ""}
>      , {"foo", "bar", "bar"}
> -    , {"/", "bar", "bar"}
> +    , {"/", "/bar", "bar"}
>      , {"\\", "bar", "bar"}
> -    , {"///", "bar", "bar"}
> +    , {"///", "///bar", "bar"}
>      , {"\\\\", "bar", "bar"}
>      , {"\\/\\", "\\/bar", "bar"}
>      , {".", "bar", "bar"}
> @@ -52,9 +53,11 @@ int main()
>    using namespace fs;
>    for (auto const & TC : TestCases) {
>      path p(TC.value);
> -    assert(p == TC.value);
> +    ASSERT_EQ(p, TC.value);
>      path& Ref = (p.replace_filename(TC.filename));
> -    assert(p == TC.expect);
> +    ASSERT_EQ(p, TC.expect)
> +        << DISPLAY(TC.value)
> +        << DISPLAY(TC.filename);
>      assert(&Ref == &p);
>      // Tests Effects "as-if": remove_filename() append(filename)
>      {
> @@ -62,7 +65,7 @@ int main()
>        path replace(TC.filename);
>        p2.remove_filename();
>        p2 /= replace;
> -      assert(p2 == p);
> +      ASSERT_EQ(p, p2);
>      }
>    }
>  }
>
> Added: libcxx/trunk/test/std/experimental/filesystem/fs.
> enum/enum.perm_options.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/fs.enum/enum.perm_options.pass.
> cpp?rev=329028&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/fs.
> enum/enum.perm_options.pass.cpp (added)
> +++ libcxx/trunk/test/std/experimental/filesystem/fs.
> enum/enum.perm_options.pass.cpp Mon Apr  2 16:03:41 2018
> @@ -0,0 +1,48 @@
> +//===------------------------------------------------------
> ----------------===//
> +//
> +//                     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.
> +//
> +//===------------------------------------------------------
> ----------------===//
> +
> +// UNSUPPORTED: c++98, c++03
> +
> +// <experimental/filesystem>
> +
> +// enum class perm_options;
> +
> +#include "filesystem_include.hpp"
> +#include <type_traits>
> +#include <cassert>
> +#include <sys/stat.h>
> +
> +#include "test_macros.h"
> +#include "check_bitmask_types.hpp"
> +
> +
> +constexpr fs::perm_options ME(int val) {
> +  return static_cast<fs::perm_options>(val);
> +}
> +
> +int main() {
> +  typedef fs::perm_options E;
> +  static_assert(std::is_enum<E>::value, "");
> +
> +  // Check that E is a scoped enum by checking for conversions.
> +  typedef std::underlying_type<E>::type UT;
> +  static_assert(!std::is_convertible<E, UT>::value, "");
> +
> +  static_assert(std::is_same<UT, unsigned char >::value, ""); //
> Implementation detail
> +
> +  typedef check_bitmask_type<E, E::replace, E::nofollow> BitmaskTester;
> +  assert(BitmaskTester::check());
> +
> +  static_assert(
> +        E::replace  == ME(1) &&
> +        E::add      == ME(2) &&
> +        E::remove   == ME(4) &&
> +        E::nofollow == ME(8),
> +        "Expected enumeration values do not match");
> +}
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.absolute/absolute.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/fs.op.funcs/fs.op.absolute/absolute.
> pass.cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.absolute/absolute.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.absolute/absolute.pass.cpp Mon Apr  2 16:03:41 2018
> @@ -28,89 +28,30 @@ TEST_SUITE(filesystem_absolute_path_test
>  TEST_CASE(absolute_signature_test)
>  {
>      const path p; ((void)p);
> +    std::error_code ec;
>      ASSERT_NOT_NOEXCEPT(absolute(p));
> -    ASSERT_NOT_NOEXCEPT(absolute(p, p));
> +    ASSERT_NOT_NOEXCEPT(absolute(p, ec));
>  }
>
> -// There are 4 cases is the proposal for absolute path.
> -// Each scope tests one of the cases.
> -TEST_CASE(absolute_path_test)
> -{
> -    // has_root_name() && has_root_directory()
> -    {
> -        const path p("//net/foo");
> -        const path base("//net/bar/baz");
> -        TEST_REQUIRE(p.has_root_name());
> -        TEST_REQUIRE(p.has_root_directory());
> -        TEST_CHECK(p.is_absolute());
> -        path ret = absolute(p, base);
> -        TEST_CHECK(ret.is_absolute());
> -        TEST_CHECK(ret == p);
> -    }
> -    // !has_root_name() && has_root_directory()
> -    {
> -        const path p("/foo");
> -        const path base("//net/bar");
> -        TEST_REQUIRE(not p.has_root_name());
> -        TEST_REQUIRE(p.has_root_directory());
> -        TEST_CHECK(p.is_absolute());
> -        // ensure absolute(base) is not recursively called
> -        TEST_REQUIRE(base.has_root_name());
> -        TEST_REQUIRE(base.has_root_directory());
> -
> -        path ret = absolute(p, base);
> -        TEST_CHECK(ret.is_absolute());
> -        TEST_CHECK(ret.has_root_name());
> -        TEST_CHECK(ret.root_name() == path("//net"));
> -        TEST_CHECK(ret.has_root_directory());
> -        TEST_CHECK(ret.root_directory() == path("/"));
> -        TEST_CHECK(ret == path("//net/foo"));
> -    }
> -    // has_root_name() && !has_root_directory()
> -    {
> -        const path p("//net");
> -        const path base("//net/foo/bar");
> -        TEST_REQUIRE(p.has_root_name());
> -        TEST_REQUIRE(not p.has_root_directory());
> -        TEST_CHECK(not p.is_absolute());
> -        // absolute is called recursively on base. The following
> conditions
> -        // must be true for it to return base unmodified
> -        TEST_REQUIRE(base.has_root_name());
> -        TEST_REQUIRE(base.has_root_directory());
> -        path ret = absolute(p, base);
> -        const path expect("//net/foo/bar");
> -        TEST_CHECK(ret.is_absolute());
> -        TEST_CHECK(ret == path("//net/foo/bar"));
> -    }
> -    // !has_root_name() && !has_root_directory()
> -    {
> -        const path p("bar/baz");
> -        const path base("//net/foo");
> -        TEST_REQUIRE(not p.has_root_name());
> -        TEST_REQUIRE(not p.has_root_directory());
> -        TEST_REQUIRE(base.has_root_name());
> -        TEST_REQUIRE(base.has_root_directory());
> -
> -        path ret = absolute(p, base);
> -        TEST_CHECK(ret.is_absolute());
> -        TEST_CHECK(ret == path("//net/foo/bar/baz"));
> -    }
> -}
>
> -TEST_CASE(absolute_path_with_default_base)
> +TEST_CASE(basic_test)
>  {
> -    const path testCases[] = {
> -        "//net/foo", //  has_root_name() &&  has_root_directory()
> -        "/foo",      // !has_root_name() &&  has_root_directory()
> -        "//net",     //  has_root_name() && !has_root_directory()
> -        "bar/baz"    // !has_root_name() && !has_root_directory()
> +    const fs::path cwd = fs::current_path();
> +    const struct {
> +      std::string input;
> +      std::string expect;
> +    } TestCases [] = {
> +        {"", cwd / ""},
> +        {"foo", cwd / "foo"},
> +        {"foo/", cwd / "foo/"},
> +        {"/already_absolute", "/already_absolute"}
>      };
> -    const path base = current_path();
> -    for (auto& p : testCases) {
> -        const path ret = absolute(p);
> -        const path expect = absolute(p, base);
> +    for (auto& TC : TestCases) {
> +        std::error_code ec = GetTestEC();
> +        const path ret = absolute(TC.input, ec);
> +        TEST_CHECK(!ec);
>          TEST_CHECK(ret.is_absolute());
> -        TEST_CHECK(ret == expect);
> +        TEST_CHECK(PathEq(ret, TC.expect));
>      }
>  }
>
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.canonical/canonical.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/fs.op.funcs/fs.op.canonical/
> canonical.pass.cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.canonical/canonical.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.canonical/canonical.pass.cpp Mon Apr  2 16:03:41 2018
> @@ -11,9 +11,8 @@
>
>  // <experimental/filesystem>
>
> -// path canonical(const path& p, const path& base = current_path());
> +// path canonical(const path& p);
>  // path canonical(const path& p, error_code& ec);
> -// path canonical(const path& p, const path& base, error_code& ec);
>
>  #include "filesystem_include.hpp"
>  #include <type_traits>
> @@ -25,6 +24,15 @@
>
>  using namespace fs;
>
> +struct CWDGuard {
> +  path OldCWD;
> +  CWDGuard() : OldCWD(fs::current_path()) { }
> +  ~CWDGuard() { fs::current_path(OldCWD); }
> +
> +  CWDGuard(CWDGuard const&) = delete;
> +  CWDGuard& operator=(CWDGuard const&) = delete;
> +};
> +
>  TEST_SUITE(filesystem_canonical_path_test_suite)
>
>  TEST_CASE(signature_test)
> @@ -32,15 +40,14 @@ TEST_CASE(signature_test)
>      const path p; ((void)p);
>      std::error_code ec; ((void)ec);
>      ASSERT_NOT_NOEXCEPT(canonical(p));
> -    ASSERT_NOT_NOEXCEPT(canonical(p, p));
>      ASSERT_NOT_NOEXCEPT(canonical(p, ec));
> -    ASSERT_NOT_NOEXCEPT(canonical(p, p, ec));
>  }
>
>  // There are 4 cases is the proposal for absolute path.
>  // Each scope tests one of the cases.
>  TEST_CASE(test_canonical)
>  {
> +    CWDGuard guard;
>      // has_root_name() && has_root_directory()
>      const path Root = StaticEnv::Root;
>      const path RootName = Root.filename();
> @@ -65,54 +72,51 @@ TEST_CASE(test_canonical)
>          { SymlinkName, StaticEnv::File, StaticEnv::Root}
>      };
>      for (auto& TC : testCases) {
> -        std::error_code ec;
> -        const path ret = canonical(TC.p, TC.base, ec);
> +        std::error_code ec = GetTestEC();
> +        fs::current_path(TC.base);
> +        const path ret = canonical(TC.p, ec);
>          TEST_REQUIRE(!ec);
> -        const path ret2 = canonical(TC.p, TC.base);
> -        TEST_CHECK(ret == TC.expect);
> -        TEST_CHECK(ret == ret2);
> +        const path ret2 = canonical(TC.p);
> +        TEST_CHECK(PathEq(ret, TC.expect));
> +        TEST_CHECK(PathEq(ret, ret2));
>          TEST_CHECK(ret.is_absolute());
>      }
>  }
>
>  TEST_CASE(test_dne_path)
>  {
> -    std::error_code ec;
> +    std::error_code ec = GetTestEC();
>      {
>          const path ret = canonical(StaticEnv::DNE, ec);
> -        TEST_REQUIRE(ec);
> -        TEST_CHECK(ret == path{});
> -    }
> -    ec.clear();
> -    {
> -        const path ret = canonical(StaticEnv::DNE, StaticEnv::Root, ec);
> +        TEST_CHECK(ec != GetTestEC());
>          TEST_REQUIRE(ec);
>          TEST_CHECK(ret == path{});
>      }
>      {
>          TEST_CHECK_THROW(filesystem_error, canonical(StaticEnv::DNE));
> -        TEST_CHECK_THROW(filesystem_error, canonical(StaticEnv::DNE,
> StaticEnv::Root));
>      }
>  }
>
>  TEST_CASE(test_exception_contains_paths)
>  {
>  #ifndef TEST_HAS_NO_EXCEPTIONS
> +    CWDGuard guard;
>      const path p = "blabla/dne";
> -    const path base = StaticEnv::Root;
>      try {
> -        canonical(p, base);
> +        canonical(p);
>          TEST_REQUIRE(false);
>      } catch (filesystem_error const& err) {
>          TEST_CHECK(err.path1() == p);
> -        TEST_CHECK(err.path2() == base);
> +        // libc++ provides the current path as the second path in the
> exception
> +        LIBCPP_ONLY(TEST_CHECK(err.path2() == current_path()));
>      }
> +    fs::current_path(StaticEnv::Dir);
>      try {
>          canonical(p);
>          TEST_REQUIRE(false);
>      } catch (filesystem_error const& err) {
>          TEST_CHECK(err.path1() == p);
> -        TEST_CHECK(err.path2() == current_path());
> +        LIBCPP_ONLY(TEST_CHECK(err.path2() == StaticEnv::Dir));
>      }
>  #endif
>  }
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.last_write_time/last_write_time.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/fs.op.funcs/fs.op.last_write_time/
> last_write_time.pass.cpp?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.last_write_time/last_write_time.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.last_write_time/last_write_time.pass.cpp Mon Apr  2 16:03:41
> 2018
> @@ -17,7 +17,6 @@
>  // void last_write_time(const path& p, file_time_type new_type,
>  //                      std::error_code& ec) noexcept;
>
> -
>  #include "filesystem_include.hpp"
>  #include <type_traits>
>  #include <chrono>
> @@ -33,7 +32,6 @@
>
>  using namespace fs;
>
> -
>  std::pair<std::time_t, std::time_t> GetTimes(path const& p) {
>      using Clock = file_time_type::clock;
>      struct ::stat st;
>
> Added: libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.proximate/proximate.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/fs.op.funcs/fs.op.proximate/
> proximate.pass.cpp?rev=329028&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.proximate/proximate.pass.cpp (added)
> +++ libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.proximate/proximate.pass.cpp Mon Apr  2 16:03:41 2018
> @@ -0,0 +1,125 @@
> +//===------------------------------------------------------
> ----------------===//
> +//
> +//                     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.
> +//
> +//===------------------------------------------------------
> ----------------===//
> +
> +// UNSUPPORTED: c++98, c++03
> +
> +// <experimental/filesystem>
> +
> +// path proximate(const path& p, error_code &ec)
> +// path proximate(const path& p, const path& base = current_path())
> +// path proximate(const path& p, const path& base, error_code& ec);
> +
> +#include "filesystem_include.hpp"
> +#include <type_traits>
> +#include <vector>
> +#include <iostream>
> +#include <cassert>
> +
> +#include "test_macros.h"
> +#include "test_iterators.h"
> +#include "count_new.hpp"
> +#include "rapid-cxx-test.hpp"
> +#include "filesystem_test_helper.hpp"
> +
> +
> +static int count_path_elems(const fs::path& p) {
> +  int count = 0;
> +  for (auto& elem : p) {
> +    if (elem != "/" && elem != "")
> +      ++count;
> +  }
> +  return count;
> +}
> +
> +TEST_SUITE(filesystem_proximate_path_test_suite)
> +
> +
> +TEST_CASE(signature_test)
> +{
> +    using fs::path;
> +    const path p; ((void)p);
> +    std::error_code ec; ((void)ec);
> +    ASSERT_NOT_NOEXCEPT(proximate(p));
> +    ASSERT_NOT_NOEXCEPT(proximate(p, p));
> +    ASSERT_NOT_NOEXCEPT(proximate(p, ec));
> +    ASSERT_NOT_NOEXCEPT(proximate(p, p, ec));
> +}
> +
> +TEST_CASE(basic_test) {
> +  using fs::path;
> +  const path cwd = fs::current_path();
> +  const path parent_cwd = cwd.parent_path();
> +  const path curdir = cwd.filename();
> +  TEST_REQUIRE(!cwd.native().empty());
> +  int cwd_depth = count_path_elems(cwd);
> +  path dot_dot_to_root;
> +  for (int i=0; i < cwd_depth; ++i)
> +    dot_dot_to_root /= "..";
> +  path relative_cwd = cwd.native().substr(1);
> +  // clang-format off
> +  struct {
> +    std::string input;
> +    std::string base;
> +    std::string expect;
> +  } TestCases[] = {
> +      {"", "", "."},
> +      {cwd, "a", ".."},
> +      {parent_cwd, "a", "../.."},
> +      {"a", cwd, "a"},
> +      {"a", parent_cwd, "fs.op.proximate/a"},
> +      {"/", "a", dot_dot_to_root / ".."},
> +      {"/", "a/b", dot_dot_to_root / "../.."},
> +      {"/", "a/b/", dot_dot_to_root / "../../.."},
> +      {"a", "/", relative_cwd / "a"},
> +      {"a/b", "/", relative_cwd / "a/b"},
> +      {"a", "/net", ".." / relative_cwd / "a"},
> +      {"//net/", "//net", "/net/"},
> +      {"//net", "//net/", ".."},
> +      {"//net", "//net", "."},
> +      {"//net/", "//net/", "."},
> +      {"//base", "a", dot_dot_to_root / "../base"},
> +      {"a", "a", "."},
> +      {"a/b", "a/b", "."},
> +      {"a/b/c/", "a/b/c/", "."},
> +      {"//net/a/b", "//net/a/b", "."},
> +      {"/a/d", "/a/b/c", "../../d"},
> +      {"/a/b/c", "/a/d", "../b/c"},
> +      {"a/b/c", "a", "b/c"},
> +      {"a/b/c", "a/b/c/x/y", "../.."},
> +      {"a/b/c", "a/b/c", "."},
> +      {"a/b", "c/d", "../../a/b"}
> +  };
> +  // clang-format on
> +  int ID = 0;
> +  for (auto& TC : TestCases) {
> +    ++ID;
> +    std::error_code ec = GetTestEC();
> +    fs::path p(TC.input);
> +    const fs::path output = fs::proximate(p, TC.base, ec);
> +    TEST_CHECK(!ec);
> +    TEST_CHECK(PathEq(output, TC.expect));
> +    if (!PathEq(output, TC.expect)) {
> +      const path canon_input = fs::weakly_canonical(TC.input);
> +      const path canon_base = fs::weakly_canonical(TC.base);
> +      const path lexically_p = canon_input.lexically_
> proximate(canon_base);
> +      std::cerr << "TEST CASE #" << ID << " FAILED: \n";
> +      std::cerr << "  Input: '" << TC.input << "'\n";
> +      std::cerr << "  Base: '" << TC.base << "'\n";
> +      std::cerr << "  Expected: '" << TC.expect << "'\n";
> +      std::cerr << "  Output:   '" << output.native() << "'\n";
> +      std::cerr << "  Lex Prox: '" << lexically_p.native() << "'\n";
> +      std::cerr << "  Canon Input: " <<  canon_input << "\n";
> +      std::cerr << "  Canon Base: " << canon_base << "\n";
> +
> +      std::cerr << std::endl;
> +    }
> +  }
> +}
> +
> +TEST_SUITE_END()
>
> Added: libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.relative/relative.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/fs.op.funcs/fs.op.relative/relative.
> pass.cpp?rev=329028&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.relative/relative.pass.cpp (added)
> +++ libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.relative/relative.pass.cpp Mon Apr  2 16:03:41 2018
> @@ -0,0 +1,78 @@
> +//===------------------------------------------------------
> ----------------===//
> +//
> +//                     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.
> +//
> +//===------------------------------------------------------
> ----------------===//
> +
> +// UNSUPPORTED: c++98, c++03
> +
> +// <experimental/filesystem>
> +
> +// path proximate(const path& p, error_code &ec)
> +// path proximate(const path& p, const path& base = current_path())
> +// path proximate(const path& p, const path& base, error_code& ec);
> +
> +#include "filesystem_include.hpp"
> +#include <type_traits>
> +#include <vector>
> +#include <iostream>
> +#include <cassert>
> +
> +#include "test_macros.h"
> +#include "test_iterators.h"
> +#include "count_new.hpp"
> +#include "rapid-cxx-test.hpp"
> +#include "filesystem_test_helper.hpp"
> +
> +
> +TEST_SUITE(filesystem_proximate_path_test_suite)
> +
> +TEST_CASE(test_signature) {
> +
> +}
> +int main() {
> +  // clang-format off
> +  struct {
> +    std::string input;
> +    std::string expect;
> +  } TestCases[] = {
> +      {"", fs::current_path()},
> +      {".", fs::current_path()},
> +      {StaticEnv::File, StaticEnv::File},
> +      {StaticEnv::Dir, StaticEnv::Dir},
> +      {StaticEnv::SymlinkToDir, StaticEnv::Dir},
> +      {StaticEnv::SymlinkToDir / "dir2/.", StaticEnv::Dir / "dir2"},
> +      // FIXME? If the trailing separator occurs in a part of the path
> that exists,
> +      // it is ommitted. Otherwise it is added to the end of the result.
> +      {StaticEnv::SymlinkToDir / "dir2/./", StaticEnv::Dir / "dir2"},
> +      {StaticEnv::SymlinkToDir / "dir2/DNE/./", StaticEnv::Dir /
> "dir2/DNE/"},
> +      {StaticEnv::SymlinkToDir / "dir2", StaticEnv::Dir2},
> +      {StaticEnv::SymlinkToDir / "dir2/../dir2/DNE/..", StaticEnv::Dir2 /
> ""},
> +      {StaticEnv::SymlinkToDir / "dir2/dir3/../DNE/DNE2", StaticEnv::Dir2
> / "DNE/DNE2"},
> +      {StaticEnv::Dir / "../dir1", StaticEnv::Dir},
> +      {StaticEnv::Dir / "./.", StaticEnv::Dir},
> +      {StaticEnv::Dir / "DNE/../foo", StaticEnv::Dir / "foo"}
> +  };
> +  // clang-format on
> +  int ID = 0;
> +  bool Failed = false;
> +  for (auto& TC : TestCases) {
> +    ++ID;
> +    fs::path p(TC.input);
> +    const fs::path output = fs::weakly_canonical(p);
> +    if (output != TC.expect) {
> +      Failed = true;
> +      std::cerr << "TEST CASE #" << ID << " FAILED: \n";
> +      std::cerr << "  Input: '" << TC.input << "'\n";
> +      std::cerr << "  Expected: '" << TC.expect << "'\n";
> +      std::cerr << "  Output: '" << output.native() << "'";
> +      std::cerr << std::endl;
> +    }
> +  }
> +  return Failed;
> +}
> +
> +TEST_SUITE_END()
>
> Removed: libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.system_complete/system_complete.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/fs.op.funcs/fs.op.system_complete/
> system_complete.pass.cpp?rev=329027&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.system_complete/system_complete.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.system_complete/system_complete.pass.cpp (removed)
> @@ -1,58 +0,0 @@
> -//===------------------------------------------------------
> ----------------===//
> -//
> -//                     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.
> -//
> -//===------------------------------------------------------
> ----------------===//
> -
> -// UNSUPPORTED: c++98, c++03
> -
> -// <experimental/filesystem>
> -
> -// path system_complete(const path& p);
> -// path system_complete(const path& p, error_code& ec);
> -
> -// Note: For POSIX based operating systems, 'system_complete(p)' has the
> -// same semantics as 'absolute(p, current_path())'.
> -
> -#include "filesystem_include.hpp"
> -#include <type_traits>
> -#include <cassert>
> -
> -#include "test_macros.h"
> -#include "rapid-cxx-test.hpp"
> -#include "filesystem_test_helper.hpp"
> -
> -using namespace fs;
> -
> -TEST_SUITE(filesystem_system_complete_test_suite)
> -
> -TEST_CASE(signature_test)
> -{
> -    const path p; ((void)p);
> -    std::error_code ec; ((void)ec);
> -    ASSERT_NOT_NOEXCEPT(system_complete(p));
> -    ASSERT_NOT_NOEXCEPT(system_complete(p, ec));
> -}
> -
> -
> -TEST_CASE(basic_system_complete_tests)
> -{
> -    const path testCases[] = {
> -        "//net/foo", //  has_root_name() &&  has_root_directory()
> -        "/foo",      // !has_root_name() &&  has_root_directory()
> -        "//net",     //  has_root_name() && !has_root_directory()
> -        "bar/baz"    // !has_root_name() && !has_root_directory()
> -    };
> -    const path base = current_path();
> -    for (auto& p : testCases) {
> -        const path ret = system_complete(p);
> -        const path expect = absolute(p, base);
> -        TEST_CHECK(ret.is_absolute());
> -        TEST_CHECK(ret == expect);
> -    }
> -}
> -
> -TEST_SUITE_END()
>
> Added: libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.weakly_canonical/weakly_canonical.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/fs.op.funcs/fs.op.weakly_canonical/
> weakly_canonical.pass.cpp?rev=329028&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.weakly_canonical/weakly_canonical.pass.cpp (added)
> +++ libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.weakly_canonical/weakly_canonical.pass.cpp Mon Apr  2
> 16:03:41 2018
> @@ -0,0 +1,76 @@
> +//===------------------------------------------------------
> ----------------===//
> +//
> +//                     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.
> +//
> +//===------------------------------------------------------
> ----------------===//
> +
> +// UNSUPPORTED: c++98, c++03
> +
> +// <experimental/filesystem>
> +
> +// path weakly_canonical(const path& p);
> +// path weakly_canonical(const path& p, error_code& ec);
> +
> +#include "filesystem_include.hpp"
> +#include <type_traits>
> +#include <vector>
> +#include <iostream>
> +#include <cassert>
> +
> +#include "test_macros.h"
> +#include "test_iterators.h"
> +#include "count_new.hpp"
> +#include "filesystem_test_helper.hpp"
> +
> +
> +int main() {
> +  // clang-format off
> +  struct {
> +    std::string input;
> +    std::string expect;
> +  } TestCases[] = {
> +      {"", fs::current_path()},
> +      {".", fs::current_path()},
> +      {"/", "/"},
> +      {"/foo", "/foo"},
> +      {"/.", "/"},
> +      {"/./", "/"},
> +      {"a/b", fs::current_path() / "a/b"},
> +      {"a", fs::current_path() / "a"},
> +      {"a/b/", fs::current_path() / "a/b/"},
> +      {StaticEnv::File, StaticEnv::File},
> +      {StaticEnv::Dir, StaticEnv::Dir},
> +      {StaticEnv::SymlinkToDir, StaticEnv::Dir},
> +      {StaticEnv::SymlinkToDir / "dir2/.", StaticEnv::Dir / "dir2"},
> +      // FIXME? If the trailing separator occurs in a part of the path
> that exists,
> +      // it is ommitted. Otherwise it is added to the end of the result.
> +      {StaticEnv::SymlinkToDir / "dir2/./", StaticEnv::Dir / "dir2"},
> +      {StaticEnv::SymlinkToDir / "dir2/DNE/./", StaticEnv::Dir /
> "dir2/DNE/"},
> +      {StaticEnv::SymlinkToDir / "dir2", StaticEnv::Dir2},
> +      {StaticEnv::SymlinkToDir / "dir2/../dir2/DNE/..", StaticEnv::Dir2 /
> ""},
> +      {StaticEnv::SymlinkToDir / "dir2/dir3/../DNE/DNE2", StaticEnv::Dir2
> / "DNE/DNE2"},
> +      {StaticEnv::Dir / "../dir1", StaticEnv::Dir},
> +      {StaticEnv::Dir / "./.", StaticEnv::Dir},
> +      {StaticEnv::Dir / "DNE/../foo", StaticEnv::Dir / "foo"}
> +  };
> +  // clang-format on
> +  int ID = 0;
> +  bool Failed = false;
> +  for (auto& TC : TestCases) {
> +    ++ID;
> +    fs::path p(TC.input);
> +    const fs::path output = fs::weakly_canonical(p);
> +    if (!PathEq(output, TC.expect)) {
> +      Failed = true;
> +      std::cerr << "TEST CASE #" << ID << " FAILED: \n";
> +      std::cerr << "  Input: '" << TC.input << "'\n";
> +      std::cerr << "  Expected: '" << TC.expect << "'\n";
> +      std::cerr << "  Output: '" << output.native() << "'";
> +      std::cerr << std::endl;
> +    }
> +  }
> +  return Failed;
> +}
>
> Modified: libcxx/trunk/test/support/filesystem_test_helper.hpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/
> support/filesystem_test_helper.hpp?rev=329028&r1=
> 329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/support/filesystem_test_helper.hpp (original)
> +++ libcxx/trunk/test/support/filesystem_test_helper.hpp Mon Apr  2
> 16:03:41 2018
> @@ -9,7 +9,6 @@
>  #include <random>
>  #include <chrono>
>
> -
>  // static test helpers
>
>  #ifndef LIBCXX_FILESYSTEM_STATIC_TEST_ROOT
> @@ -400,4 +399,8 @@ void SleepFor(std::chrono::seconds dur)
>          ;
>  }
>
> +inline bool PathEq(fs::path const& LHS, fs::path const& RHS) {
> +  return LHS.native() == RHS.native();
> +}
> +
>  #endif /* FILESYSTEM_TEST_HELPER_HPP */
>
> Added: libcxx/trunk/test/support/verbose_assert.h
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/
> support/verbose_assert.h?rev=329028&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/test/support/verbose_assert.h (added)
> +++ libcxx/trunk/test/support/verbose_assert.h Mon Apr  2 16:03:41 2018
> @@ -0,0 +1,222 @@
> +#ifndef TEST_SUPPORT_VERBOSE_ASSERT
> +#define TEST_SUPPORT_VERBOSE_ASSERT
> +
> +#include <iostream>
> +#include <cstdio>
> +#include <sstream>
> +#include <string>
> +#include "test_macros.h"
> +
> +namespace verbose_assert {
> +
> +typedef std::basic_ostream<char>&(EndLType)(std::basic_ostream<char>&);
> +
> +template <class Stream, class Tp,
> +    class = decltype(std::declval<Stream&>() << std::declval<Tp
> const&>())>
> +std::true_type IsStreamableImp(int);
> +template <class Stream, class Tp> std::false_type IsStreamableImp(long);
> +
> +template <class Stream, class Tp>
> +struct IsStreamable : decltype(IsStreamableImp<Stream, Tp>(0)) {};
> +
> +template <class Tp, int ST = (IsStreamable<decltype(std::cerr),
> Tp>::value ? 1
> +        : (IsStreamable<decltype(std::wcerr), Tp>::value ? 2 : -1))>
> +struct SelectStream {
> +  static_assert(ST == -1, "specialization required for ST != -1");
> +  static void Print(Tp const&) { std::clog << "Value Not Streamable!\n"; }
> +};
> +
> +template <class Tp>
> +struct SelectStream<Tp, 1> {
> +  static void Print(Tp const& val) { std::cerr << val; }
> +};
> +
> +template <class Tp>
> +struct SelectStream<Tp, 2> {
> +  static void Print(Tp const& val) { std::wcerr << val; }
> +};
> +
> +struct AssertData {
> +  AssertData(const char* xcheck, const char* xfile, const char* xfunc,
> +             unsigned long xline, bool xpassed = true)
> +      : passed(xpassed), check(xcheck), file(xfile), func(xfunc),
> line(xline),
> +        msg() {}
> +
> +  AssertData& SetFailed(std::string xmsg = std::string()) {
> +    msg = xmsg;
> +    passed = false;
> +    return *this;
> +  }
> +
> +  void PrintFailed() const {
> +    std::fprintf(stderr, "%s:%lu %s: Assertion '%s' failed.\n", file,
> line,
> +                 func, check);
> +    if (!msg.empty())
> +      std::fprintf(stderr, "%s\n", msg.data());
> +  }
> +
> +  bool passed;
> +  const char* check;
> +  const char* file;
> +  const char* func;
> +  unsigned long line;
> +  std::string msg;
> +};
> +
> +// AssertHandler is the class constructed by failing CHECK macros.
> AssertHandler
> +// will log information about the failures and abort when it is
> destructed.
> +class AssertHandler {
> +public:
> +  AssertHandler(AssertData const& Data)
> +      : passed(Data.passed) {
> +    if (!passed)
> +      Data.PrintFailed();
> +  }
> +
> +  ~AssertHandler() TEST_NOEXCEPT_FALSE {
> +    if (!passed) {
> +      error_log << std::endl;
> +      std::abort();
> +    }
> +  }
> +
> +  class LogType {
> +    friend class AssertHandler;
> +
> +    template <class Tp>
> +    friend LogType& operator<<(LogType& log, Tp const& value) {
> +      if (!log.is_disabled) {
> +        SelectStream<Tp>::Print(value);
> +      }
> +      return log;
> +    }
> +
> +    friend LogType& operator<<(LogType& log, EndLType* m) {
> +      if (!log.is_disabled) {
> +        SelectStream<EndLType*>::Print(m);
> +      }
> +      return log;
> +    }
> +
> +  private:
> +    LogType(bool disable) : is_disabled(disable) {}
> +    bool is_disabled;
> +
> +    LogType(LogType const&);
> +    LogType& operator=(LogType const&);
> +  };
> +
> +  LogType& GetLog() {
> +    if (passed)
> +      return null_log;
> +    return error_log;
> +  }
> +
> +private:
> +  static LogType null_log;
> +  static LogType error_log;
> +
> +  AssertHandler& operator=(const AssertHandler&) = delete;
> +  AssertHandler(const AssertHandler&) = delete;
> +  AssertHandler() = delete;
> +
> +private:
> +  bool passed;
> +};
> +
> +AssertHandler::LogType AssertHandler::null_log(true);
> +AssertHandler::LogType AssertHandler::error_log(false);
> +
> +template <class It1>
> +std::string PrintRange(const char* Name, It1 F, It1 E) {
> +  std::stringstream ss;
> +  ss << "  " << Name << " = [";
> +  while (F != E) {
> +    ss << *F;
> +    ++F;
> +    if (F != E)
> +      ss << ", ";
> +  }
> +  ss << "]\n";
> +  return ss.str();
> +}
> +
> +template <class Tp, class Up>
> +std::string PrintMismatch(Tp const& LHS, Up const& RHS, int Elem) {
> +  std::stringstream ss;
> +  ss << "  Element " << Elem << " mismatched: `" << LHS << "` != `" << RHS
> +     << "`!\n";
> +  return ss.str();
> +};
> +
> +struct EqualToComp {
> +  template <class Tp, class Up>
> +  bool operator()(Tp const& LHS, Up const& RHS) const {
> +    return LHS == RHS;
> +  }
> +};
> +
> +template <class It1, class It2, class Comp>
> +AssertData CheckCollectionsEqual(It1 F1, It1 E1, It2 F2, It2 E2,
> +                                 AssertData Data, Comp C = EqualToComp())
> {
> +  const It1 F1Orig = F1;
> +  const It2 F2Orig = F2;
> +  bool Failed = false;
> +  std::string ErrorMsg;
> +  int Idx = 0;
> +  while (F1 != E1 && F2 != E2) {
> +    if (!(C(*F1, *F2))) {
> +      ErrorMsg += PrintMismatch(*F1, *F2, Idx);
> +      Failed = true;
> +      break;
> +    }
> +    ++Idx;
> +    ++F1;
> +    ++F2;
> +  }
> +  if (!Failed && (F1 != E1 || F2 != E2)) {
> +    ErrorMsg += "  Ranges have different sizes!\n";
> +    Failed = true;
> +  }
> +  if (Failed) {
> +    ErrorMsg += PrintRange("LHS", F1Orig, E1);
> +    ErrorMsg += PrintRange("RHS", F2Orig, E2);
> +    Data.SetFailed(ErrorMsg);
> +  }
> +  return Data;
> +}
> +} // namespace verbose_assert
> +
> +#ifdef __GNUC__
> +#define ASSERT_FN_NAME() __PRETTY_FUNCTION__
> +#else
> +#define ASSERT_FN_NAME() __func__
> +#endif
> +
> +#define DISPLAY(...) "    " #__VA_ARGS__ " = " << (__VA_ARGS__) << "\n"
> +
> +#define ASSERT(...)
>       \
> +  ::verbose_assert::AssertHandler(::verbose_assert::AssertData(
>       \
> +    #__VA_ARGS__, __FILE__, ASSERT_FN_NAME(), __LINE__,(__VA_ARGS__))).
> GetLog()
> +
> +#define ASSERT_EQ(LHS, RHS) \
> +  ASSERT(LHS == RHS) << DISPLAY(LHS) << DISPLAY(RHS)
> +#define ASSERT_NEQ(LHS, RHS) \
> +  ASSERT(LHS != RHS) << DISPLAY(LHS) << DISPLAY(RHS)
> +#define ASSERT_PRED(PRED, LHS, RHS) \
> +  ASSERT(PRED(LHS, RHS)) << DISPLAY(LHS) << DISPLAY(RHS)
> +
> +#define ASSERT_COLLECTION_EQ_COMP(F1, E1, F2, E2, Comp)
>       \
> +  (::verbose_assert::AssertHandler(
>       \
> +       ::verbose_assert::CheckCollectionsEqual(
>       \
> +           F1, E1, F2, E2,
>      \
> +           ::verbose_assert::AssertData("CheckCollectionsEqual(" #F1 ",
> " #E1  \
> +                                        ", " #F2 ", " #E2 ")",
>      \
> +                                        __FILE__, ASSERT_FN_NAME(),
> __LINE__), \
> +           Comp))
>       \
> +       .GetLog())
> +
> +#define ASSERT_COLLECTION_EQ(F1, E1, F2, E2)
>      \
> +  ASSERT_COLLECTION_EQ_COMP(F1, E1, F2, E2, ::verbose_assert::EqualToComp(
> ))
> +
> +#endif
>
> Modified: libcxx/trunk/www/cxx1z_status.html
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/www/
> cxx1z_status.html?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/www/cxx1z_status.html (original)
> +++ libcxx/trunk/www/cxx1z_status.html Mon Apr  2 16:03:41 2018
> @@ -111,7 +111,7 @@
>         <tr><td><a href="https://wg21.link/p0180r2">p0180r2</a></td><td>LWG</td><td>Reserve
> a New Library Namespace for Future Standardization</td><td>Oulu</td><td><i>Nothing
> to do</i></td><td>n/a</td></tr>
>         <tr><td><a href="https://wg21.link/p0181r1">p0181r1</a></td><td>LWG</td><td>Ordered
> by Default</td><td>Oulu</td><td><i>Removed in
> Kona</i></td><td>n/a</td></tr>
>         <tr><td><a href="https://wg21.link/p0209r2">p0209r2</a></td><td>LWG</td><td>make_from_tuple:
> apply for construction</td><td>Oulu</td><td>Complete</td><td>3.9</td></tr>
> -       <tr><td><a href="https://wg21.link/p0219r1">p0219r1</a></td><td>LWG</td><td>Relative
> Paths for Filesystem</td><td>Oulu</td><td></td><td></td></tr>
> +       <tr><td><a href="https://wg21.link/p0219r1">p0219r1</a></td><td>LWG</td><td>Relative
> Paths for Filesystem</td><td>Oulu</td><td>Complete</td><td>7.0</td></tr>
>         <tr><td><a href="https://wg21.link/p0254r2">p0254r2</a></td><td>LWG</td><td>Integrating
> std::string_view and std::string</td><td>Oulu</td><
> td>Complete</td><td>4.0</td></tr>
>         <tr><td><a href="https://wg21.link/p0258r2">p0258r2</a></td><td>
> LWG</td><td>has_unique_object_representations</td><td>Oulu</
> td><td>Complete</td><td>6.0</td></tr>
>         <tr><td><a href="https://wg21.link/p0295r0">p0295r0</a></td><td>LWG</td><td>Adopt
> Selected Library Fundamentals V2 Components for C++17</td><td>Oulu</td><td>
> Complete</td><td>4.0</td></tr>
> @@ -153,7 +153,7 @@
>         <tr><td><a href="https://wg21.link/P0433R2">P0433R2</a></td><td>LWG</td><td>Toward
> a resolution of US7 and US14: Integrating template deduction for class
> templates into the standard library</td><td>Kona</td><td><i>In
> progress</i></td><td>7.0</td></tr>
>         <tr><td><a href="https://wg21.link/P0452R1">P0452R1</a></td><td>LWG</td><td>Unifying
> <numeric> Parallel Algorithms</td><td>Kona</td><
> td></td><td></td></tr>
>         <tr><td><a href="https://wg21.link/P0467R2">P0467R2</a></td><td>LWG</td><td>Iterator
> Concerns for Parallel Algorithms</td><td>Kona</td><td></td><td></td></tr>
> -       <tr><td><a href="https://wg21.link/P0492R2">P0492R2</a></td><td>LWG</td><td>Proposed
> Resolution of C++17 National Body Comments for
> Filesystems</td><td>Kona</td><td></td><td></td></tr>
> +       <tr><td><a href="https://wg21.link/P0492R2">P0492R2</a></td><td>LWG</td><td>Proposed
> Resolution of C++17 National Body Comments for
> Filesystems</td><td>Kona</td><td>Complete</td><td>7.0</td></tr>
>         <tr><td><a href="https://wg21.link/P0518R1">P0518R1</a></td><td>LWG</td><td>Allowing
> copies as arguments to function objects given to parallel algorithms in
> response to CH11</td><td>Kona</td><td></td><td></td></tr>
>         <tr><td><a href="https://wg21.link/P0523R1">P0523R1</a></td><td>LWG</td><td>Wording
> for CH 10: Complexity of parallel algorithms</td><td>Kona</td><
> td></td><td></td></tr>
>         <tr><td><a href="https://wg21.link/P0548R1">P0548R1</a></td><td>LWG</td><td>common_type
> and duration</td><td>Kona</td><td>Complete</td><td>5.0</td></tr>
>
> Modified: libcxx/trunk/www/cxx2a_status.html
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/www/
> cxx2a_status.html?rev=329028&r1=329027&r2=329028&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/www/cxx2a_status.html (original)
> +++ libcxx/trunk/www/cxx2a_status.html Mon Apr  2 16:03:41 2018
> @@ -164,7 +164,7 @@
>         <tr><td><a href="https://wg21.link/LWG3015">3015</a></td><td><tt>
> copy_options::<i>unspecified</i></tt> underspecified</td><td>
> Jacksonville</td><td><i>Nothing to do</i></td></tr>
>         <tr><td><a href="https://wg21.link/LWG3017">3017</a></td><td><tt>list
> splice</tt> functions should use <tt>addressof</tt></td><td>
> Jacksonville</td><td></td></tr>
>         <tr><td><a href="https://wg21.link/LWG3020">3020</a></td><td>[networking.ts]
> Remove spurious nested <tt>value_type</tt> buffer sequence
> requirement</td><td>Jacksonville</td><td></td></tr>
> -       <tr><td><a href="https://wg21.link/LWG3026">3026</a></td><td><tt>
> filesystem::weakly_canonical</tt> still defined in terms of
> <tt>canonical(p, base)</tt></td><td>Jacksonville</td><td></td></tr>
> +       <tr><td><a href="https://wg21.link/LWG3026">3026</a></td><td><tt>
> filesystem::weakly_canonical</tt> still defined in terms of
> <tt>canonical(p, base)</tt></td><td>Jacksonville</td><td>Complete<
> /td></tr>
>         <tr><td><a href="https://wg21.link/LWG3030">3030</a></td><td>Who
> shall meet the requirements of <tt>try_lock</tt>?</td><td>
> Jacksonville</td><td><i>Nothing to do</i></td></tr>
>         <tr><td><a href="https://wg21.link/LWG3034">3034</a></td><td>P0767R1
> breaks previously-standard-layout types</td><td>Jacksonville</
> td><td>Complete</td></tr>
>         <tr><td><a href="https://wg21.link/LWG3035">3035</a></td><td><tt>std::allocator</tt>'s
> constructors should be <tt>constexpr</tt></td><td>
> Jacksonville</td><td>Complete</td></tr>
>
>
> _______________________________________________
> cfe-commits mailing list
> cfe-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>
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