commit 9b3f71e225ae45ccc1a5a78fee05d4ed9a969e8e
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Oct 27 11:48:00 2016 +0100

    Adjust precision of filesystem::last_write_time tests
    
    	* testsuite/experimental/filesystem/iterators/directory_iterator.cc:
    	Use end() function to get end iterator.
    	* testsuite/experimental/filesystem/iterators/pop.cc: Remove printf
    	statements that were present for debugging.
    	* testsuite/experimental/filesystem/iterators/
    	recursive_directory_iterator.cc: Use end() function to get end
    	iterator.
    	* testsuite/experimental/filesystem/operations/last_write_time.cc:
    	Only require file timestamps to be accurate to one second.

diff --git a/libstdc++-v3/testsuite/experimental/filesystem/iterators/directory_iterator.cc b/libstdc++-v3/testsuite/experimental/filesystem/iterators/directory_iterator.cc
index 5788700..d1f2c54 100644
--- a/libstdc++-v3/testsuite/experimental/filesystem/iterators/directory_iterator.cc
+++ b/libstdc++-v3/testsuite/experimental/filesystem/iterators/directory_iterator.cc
@@ -34,14 +34,14 @@ test01()
   const auto p = __gnu_test::nonexistent_path();
   fs::directory_iterator iter(p, ec);
   VERIFY( ec );
-  VERIFY( iter == fs::directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   // Test empty directory.
   create_directory(p, fs::current_path(), ec);
   VERIFY( !ec );
   iter = fs::directory_iterator(p, ec);
   VERIFY( !ec );
-  VERIFY( iter == fs::directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   // Test non-empty directory.
   create_directory_symlink(p, p / "l", ec);
@@ -51,20 +51,20 @@ test01()
   VERIFY( iter != fs::directory_iterator() );
   VERIFY( iter->path() == p/"l" );
   ++iter;
-  VERIFY( iter == fs::directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   // Test inaccessible directory.
   permissions(p, fs::perms::none, ec);
   VERIFY( !ec );
   iter = fs::directory_iterator(p, ec);
   VERIFY( ec );
-  VERIFY( iter == fs::directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   // Test inaccessible directory, skipping permission denied.
   const auto opts = fs::directory_options::skip_permission_denied;
   iter = fs::directory_iterator(p, opts, ec);
   VERIFY( !ec );
-  VERIFY( iter == fs::directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   permissions(p, fs::perms::owner_all, ec);
   remove_all(p, ec);
@@ -82,12 +82,12 @@ test02()
   // Test post-increment (libstdc++/71005)
   auto iter = fs::directory_iterator(p, ec);
   VERIFY( !ec );
-  VERIFY( iter != fs::directory_iterator() );
+  VERIFY( iter != end(iter) );
   const auto entry1 = *iter;
   const auto entry2 = *iter++;
   VERIFY( entry1 == entry2 );
   VERIFY( entry1.path() == p/"l" );
-  VERIFY( iter == fs::directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   remove_all(p, ec);
 }
diff --git a/libstdc++-v3/testsuite/experimental/filesystem/iterators/pop.cc b/libstdc++-v3/testsuite/experimental/filesystem/iterators/pop.cc
index d247ab4..9306c03 100644
--- a/libstdc++-v3/testsuite/experimental/filesystem/iterators/pop.cc
+++ b/libstdc++-v3/testsuite/experimental/filesystem/iterators/pop.cc
@@ -84,14 +84,10 @@ test03()
     std::advance(dir, i);
     int expected_depth = i;
     VERIFY( dir.depth() == expected_depth );
-    __builtin_printf("%d %d %s\n", i, dir.depth(), dir->path().c_str());
     dir.pop(ec);
     VERIFY( !ec );
     if (dir != end(dir))
-    {
-    __builtin_printf("%d %d %s\n", i, dir.depth(), dir->path().c_str());
       VERIFY( dir.depth() == (expected_depth - 1) );
-    }
 
     dir = fs::recursive_directory_iterator(p);
     std::advance(dir, i);
diff --git a/libstdc++-v3/testsuite/experimental/filesystem/iterators/recursive_directory_iterator.cc b/libstdc++-v3/testsuite/experimental/filesystem/iterators/recursive_directory_iterator.cc
index 79aa178..3dc7ba2 100644
--- a/libstdc++-v3/testsuite/experimental/filesystem/iterators/recursive_directory_iterator.cc
+++ b/libstdc++-v3/testsuite/experimental/filesystem/iterators/recursive_directory_iterator.cc
@@ -34,39 +34,39 @@ test01()
   const auto p = __gnu_test::nonexistent_path();
   fs::recursive_directory_iterator iter(p, ec);
   VERIFY( ec );
-  VERIFY( iter == fs::recursive_directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   // Test empty directory.
   create_directory(p, fs::current_path(), ec);
   VERIFY( !ec );
   iter = fs::recursive_directory_iterator(p, ec);
   VERIFY( !ec );
-  VERIFY( iter == fs::recursive_directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   // Test non-empty directory.
   create_directories(p / "d1/d2");
   VERIFY( !ec );
   iter = fs::recursive_directory_iterator(p, ec);
   VERIFY( !ec );
-  VERIFY( iter != fs::recursive_directory_iterator() );
+  VERIFY( iter != end(iter) );
   VERIFY( iter->path() == p/"d1" );
   ++iter;
   VERIFY( iter->path() == p/"d1/d2" );
   ++iter;
-  VERIFY( iter == fs::recursive_directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   // Test inaccessible directory.
   permissions(p, fs::perms::none, ec);
   VERIFY( !ec );
   iter = fs::recursive_directory_iterator(p, ec);
   VERIFY( ec );
-  VERIFY( iter == fs::recursive_directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   // Test inaccessible directory, skipping permission denied.
   const auto opts = fs::directory_options::skip_permission_denied;
   iter = fs::recursive_directory_iterator(p, opts, ec);
   VERIFY( !ec );
-  VERIFY( iter == fs::recursive_directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   // Test inaccessible sub-directory.
   permissions(p, fs::perms::owner_all, ec);
@@ -75,24 +75,24 @@ test01()
   VERIFY( !ec );
   iter = fs::recursive_directory_iterator(p, ec);
   VERIFY( !ec );
-  VERIFY( iter != fs::recursive_directory_iterator() );
+  VERIFY( iter != end(iter) );
   VERIFY( iter->path() == p/"d1" );
   ++iter;              // should recurse into d1
   VERIFY( iter->path() == p/"d1/d2" );
   iter.increment(ec);  // should fail to recurse into p/d1/d2
   VERIFY( ec );
-  VERIFY( iter == fs::recursive_directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   // Test inaccessible sub-directory, skipping permission denied.
   iter = fs::recursive_directory_iterator(p, opts, ec);
   VERIFY( !ec );
-  VERIFY( iter != fs::recursive_directory_iterator() );
+  VERIFY( iter != end(iter) );
   VERIFY( iter->path() == p/"d1" );
   ++iter;              // should recurse into d1
   VERIFY( iter->path() == p/"d1/d2" );
   iter.increment(ec);  // should fail to recurse into p/d1/d2, so skip it
   VERIFY( !ec );
-  VERIFY( iter == fs::recursive_directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   permissions(p/"d1/d2", fs::perms::owner_all, ec);
   remove_all(p, ec);
@@ -109,7 +109,7 @@ test02()
   // Test post-increment (libstdc++/71005)
   auto iter = fs::recursive_directory_iterator(p, ec);
   VERIFY( !ec );
-  VERIFY( iter != fs::recursive_directory_iterator() );
+  VERIFY( iter != end(iter) );
   const auto entry1 = *iter;
   const auto entry2 = *iter++;
   VERIFY( entry1 == entry2 );
@@ -118,7 +118,7 @@ test02()
   const auto entry4 = *iter++;
   VERIFY( entry3 == entry4 );
   VERIFY( entry3.path() == p/"d1/d2" );
-  VERIFY( iter == fs::recursive_directory_iterator() );
+  VERIFY( iter == end(iter) );
 
   remove_all(p, ec);
 }
@@ -145,7 +145,7 @@ test04()
 {
   // libstdc++/71004
   const fs::recursive_directory_iterator it;
-  VERIFY( it == fs::recursive_directory_iterator() );
+  VERIFY( it == end(it) );
 }
 
 void
diff --git a/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc b/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
index 74be4f9..a60a25f 100644
--- a/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
+++ b/libstdc++-v3/testsuite/experimental/filesystem/operations/last_write_time.cc
@@ -32,13 +32,13 @@
 # include <utime.h>
 #endif
 
+using time_type = std::experimental::filesystem::file_time_type;
+
 void
 test01()
 {
   // read times
 
-  using time_type = std::experimental::filesystem::file_time_type;
-
   auto p = __gnu_test::nonexistent_path();
   std::error_code ec;
   time_type mtime = last_write_time(p, ec);
@@ -105,13 +105,19 @@ test01()
 #endif
 }
 
+bool approx_equal(time_type file_time, time_type expected)
+{
+  auto delta = expected - file_time;
+  if (delta < delta.zero())
+    delta = -delta;
+  return delta < std::chrono::seconds(1);
+}
+
 void
 test02()
 {
   // write times
 
-  using time_type = std::experimental::filesystem::file_time_type;
-
   __gnu_test::scoped_file f;
   std::error_code ec;
   time_type time;
@@ -119,27 +125,27 @@ test02()
   time = last_write_time(f.path);
   last_write_time(f.path, time, ec);
   VERIFY( !ec );
-  VERIFY( last_write_time(f.path) == time );
+  VERIFY( approx_equal(last_write_time(f.path), time) );
 
   time -= std::chrono::milliseconds(1000 * 60 * 10 + 15);
   last_write_time(f.path, time, ec);
   VERIFY( !ec );
-  VERIFY( last_write_time(f.path) == time );
+  VERIFY( approx_equal(last_write_time(f.path), time) );
 
   time += std::chrono::milliseconds(1000 * 60 * 20 + 15);
   last_write_time(f.path, time, ec);
   VERIFY( !ec );
-  VERIFY( last_write_time(f.path) == time );
+  VERIFY( approx_equal(last_write_time(f.path), time) );
 
   time = time_type();
   last_write_time(f.path, time, ec);
   VERIFY( !ec );
-  VERIFY( last_write_time(f.path) == time );
+  VERIFY( approx_equal(last_write_time(f.path), time) );
 
   time -= std::chrono::milliseconds(1000 * 60 * 10 + 15);
   last_write_time(f.path, time, ec);
   VERIFY( !ec );
-  VERIFY( last_write_time(f.path) == time );
+  VERIFY( approx_equal(last_write_time(f.path), time) );
 }
 
 int
