Fix 3 bugs in filesystem tests and implementation.

This patch fixes the following bugs, all of which were discovered while
testing a 32 bit build on a 64 bit machine.

* path.itr/iterator.pass.cpp has undefined behavior.
  'path::iterator' stashes the value of the element inside the iterator.
  This violates the BiDirIterator requirements but is allowed for path::iterator.
  However this means that using reverse_iterator<path::iterator> has undefined
  behavior because it assumes that 'Iter tmp = it; return *tmp' will not create
  a dangling reference. However it does, and this caused this particular test
  to fail.

* path.native.obs/string_alloc.pass.cpp tested the SSO with a long string.
  On 32 bit builds std::wstring only has the SSO for strings of size 2. The
  test was using a string of size 4.

* fs.op.space/space.pass.cpp had overflows while calculating the expected values.
  The fix here is to convert the statvfs data members to std::uintmax_t before
  multiplying them. The internal implementation already does this but the tests
  needed to do it as well.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@273078 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/experimental/filesystem/class.path/path.itr/iterator.pass.cpp

@@ -24,8 +24,6 @@
 #include <type_traits>
 #include <cassert>
 
-#include <iostream>
-
 #include "test_macros.h"
 #include "filesystem_test_helper.hpp"
 
@@ -37,30 +35,6 @@ std::reverse_iterator<It> mkRev(It it) {
   return std::reverse_iterator<It>(it);
 }
 
-
-template <class Iter1, class Iter2>
-bool checkCollectionsEqualVerbose(
-    Iter1 start1, Iter1 const end1
-  , Iter2 start2, Iter2 const end2
-  )
-{
-    while (start1 != end1 && start2 != end2) {
-      std::cout << "Got start1 = " << *start1 << "\n"
-                << "Got start2 = " << *start2 << "\n";
-        if (*start1 != *start2) {
-            return false;
-        }
-        ++start1; ++start2;
-    }
-  if (start1 != end1) {
-    std::cout << "Got start1 = " << *start1 << " but expected end1\n";
-  }
-  if (start2 != end2) {
-    std::cout << "Got start2 = " << *start2 << " but expected end2\n";
-  }
-    return (start1 == end1 && start2 == end2);
-}
-
 void checkIteratorConcepts() {
   using namespace fs;
   using It = path::iterator;
@@ -112,16 +86,15 @@ void checkBeginEndBasic() {
     path p("//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(checkCollectionsEqualVerbose(mkRev(p.end()), mkRev(p.begin()),
+    assert(checkCollectionsEqualBackwards(p.begin(), p.end(), std::begin(expect), std::end(expect)));
-                                 mkRev(std::end(expect)),
+
-                                 mkRev(std::begin(expect))));
   }
   {
     path p("////foo/bar/baz///");
     const path expect[] = {"/", "foo", "bar", "baz", "."};
     assert(checkCollectionsEqual(p.begin(), p.end(), std::begin(expect), std::end(expect)));
-    assert(checkCollectionsEqual(mkRev(p.end()), mkRev(p.begin()),
+    assert(checkCollectionsEqualBackwards(p.begin(), p.end(), std::begin(expect), std::end(expect)));
-                                 mkRev(std::end(expect)), mkRev(std::begin(expect))));
+
   }
 
 }

test/std/experimental/filesystem/class.path/path.member/path.native.obs/string_alloc.pass.cpp

@@ -30,7 +30,8 @@
 
 namespace fs = std::experimental::filesystem;
 
-MultiStringType shortString = MKSTR("abc");
+// the SSO is always triggered for strings of size 2.
+MultiStringType shortString = MKSTR("a");
 MultiStringType longString = MKSTR("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ/123456789/abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");
 
 template <class CharT>
@@ -43,8 +44,6 @@ void doShortStringTest(MultiStringType const& MS) {
   const path p((const char*)MS);
   {
       DisableAllocationGuard g;
-      if (!std::is_same<CharT, char>::value)
-          g.release();
       Str s = p.string<CharT>();
       assert(s == value);
       Str s2 = p.string<CharT>(Alloc{});
@@ -55,6 +54,7 @@ void doShortStringTest(MultiStringType const& MS) {
   {
       using Traits = std::char_traits<CharT>;
       using AStr = std::basic_string<CharT, Traits, MAlloc>;
+      DisableAllocationGuard g;
       AStr s = p.string<CharT, Traits, MAlloc>();
       assert(s == value);
       assert(MAlloc::alloc_count == 0);
@@ -64,6 +64,7 @@ void doShortStringTest(MultiStringType const& MS) {
   { // Other allocator - provided copy
       using Traits = std::char_traits<CharT>;
       using AStr = std::basic_string<CharT, Traits, MAlloc>;
+      DisableAllocationGuard g;
       MAlloc a;
       // don't allow another allocator to be default constructed.
       MAlloc::disable_default_constructor = true;
@@ -94,6 +95,7 @@ void doLongStringTest(MultiStringType const& MS) {
   { // Other allocator - default construct
       using Traits = std::char_traits<CharT>;
       using AStr = std::basic_string<CharT, Traits, MAlloc>;
+      DisableAllocationGuard g;
       AStr s = p.string<CharT, Traits, MAlloc>();
       assert(s == value);
       assert(MAlloc::alloc_count > 0);
@@ -103,6 +105,7 @@ void doLongStringTest(MultiStringType const& MS) {
   { // Other allocator - provided copy
       using Traits = std::char_traits<CharT>;
       using AStr = std::basic_string<CharT, Traits, MAlloc>;
+      DisableAllocationGuard g;
       MAlloc a;
       // don't allow another allocator to be default constructed.
       MAlloc::disable_default_constructor = true;

test/std/experimental/filesystem/fs.op.funcs/fs.op.space/space.pass.cpp

@@ -88,13 +88,22 @@ TEST_CASE(basic_space_test)
     TEST_CHECK(expect.f_bfree > 0);
     TEST_CHECK(expect.f_bsize > 0);
     TEST_CHECK(expect.f_blocks > 0);
-    TEST_CHECK(expect.f_frsize > 0);
+    TEST_REQUIRE(expect.f_frsize > 0);
+    auto do_mult = [&](std::uintmax_t val) {
+        std::uintmax_t fsize = expect.f_frsize;
+        std::uintmax_t new_val = val * fsize;
+        TEST_CHECK(new_val / fsize == val); // Test for overflow
+        return new_val;
+    };
     const std::uintmax_t bad_value = static_cast<std::uintmax_t>(-1);
-    const std::uintmax_t expect_cap = expect.f_blocks * expect.f_frsize;
+    const std::uintmax_t expect_capacity = do_mult(expect.f_blocks);
+    const std::uintmax_t expect_free = do_mult(expect.f_bfree);
+    const std::uintmax_t expect_avail = do_mult(expect.f_bavail);
+
     // Other processes running on the operating system may have changed
     // the amount of space available. Check that these are within tolerances.
     // Currently 5% of capacity
-    const std::uintmax_t delta = expect_cap / 20;
+    const std::uintmax_t delta = expect_capacity / 20;
     const path cases[] = {
         StaticEnv::File,
         StaticEnv::Dir,
@@ -107,11 +116,11 @@ TEST_CASE(basic_space_test)
         space_info info = space(p, ec);
         TEST_CHECK(!ec);
         TEST_CHECK(info.capacity != bad_value);
-        TEST_CHECK((expect.f_blocks * expect.f_frsize) == info.capacity);
+        TEST_CHECK(expect_capacity == info.capacity);
         TEST_CHECK(info.free != bad_value);
-        TEST_CHECK(EqualDelta((expect.f_bfree  * expect.f_frsize), info.free, delta));
+        TEST_CHECK(EqualDelta(expect_free, info.free, delta));
         TEST_CHECK(info.available != bad_value);
-        TEST_CHECK(EqualDelta((expect.f_bavail * expect.f_frsize), info.available, delta));
+        TEST_CHECK(EqualDelta(expect_avail, info.available, delta));
     }
 }
 

test/support/filesystem_test_helper.hpp

@@ -361,6 +361,22 @@ bool checkCollectionsEqual(
     return (start1 == end1 && start2 == end2);
 }
 
+
+template <class Iter1, class Iter2>
+bool checkCollectionsEqualBackwards(
+    Iter1 const start1, Iter1 end1
+  , Iter2 const start2, Iter2 end2
+  )
+{
+    while (start1 != end1 && start2 != end2) {
+        --end1; --end2;
+        if (*end1 != *end2) {
+            return false;
+        }
+    }
+    return (start1 == end1 && start2 == end2);
+}
+
 // We often need to test that the error_code was cleared if no error occurs
 // this function returns a error_code which is set to an error that will
 // never be returned by the filesystem functions.