[committed] libstdc++: Do not use off64_t in calls to copy_file_range [PR110462]

[Jonathan Wakely]

Tested x86_64-linux. Pushed to trunk.

-- >8 --

Although the copy_file_range(2) man page shows the arguments as off64_t*
that is not portable. For musl there is no off64_t type, as off_t is
always 64-bit. Use the loff_t type which is always 64-bit even if off_t
isn't. We could just use off_t because the filesystem library is
compiled with _FILE_OFFSET_BITS=64, but loff_t is the more correct type
for this interface.

libstdc++-v3/ChangeLog:

	PR libstdc++/110462
	* acinclude.m4 (GLIBCXX_CHECK_FILESYSTEM_DEPS): Check that
	copy_file_range can be called with loff_t* arguments.
	* configure: Regenerate.
	* src/filesystem/ops-common.h (copy_file_copy_file_range):
	Use loff_t for offsets.
---
 libstdc++-v3/acinclude.m4                | 2 +-
 libstdc++-v3/configure                   | 4 ++--
 libstdc++-v3/src/filesystem/ops-common.h | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index efc27aa493e..277ae10e031 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -5160,7 +5160,7 @@ dnl
       linux*)
 	GCC_TRY_COMPILE_OR_LINK(
 	  [#include <unistd.h>],
-	  [copy_file_range(1, nullptr, 2, nullptr, 1, 0);],
+	  [copy_file_range(1, (loff_t*)nullptr, 2, (loff_t*)nullptr, 1, 0);],
 	  [glibcxx_cv_copy_file_range=yes],
 	  [glibcxx_cv_copy_file_range=no])
 	;;
diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h
index f04bbc66d7d..2e4331bb682 100644
--- a/libstdc++-v3/src/filesystem/ops-common.h
+++ b/libstdc++-v3/src/filesystem/ops-common.h
@@ -374,7 +374,7 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
 	return false;
       }
     size_t bytes_left = length;
-    off64_t off_in = 0, off_out = 0;
+    loff_t off_in = 0, off_out = 0;
     ssize_t bytes_copied;
     do
       {
-- 
2.41.0