Make all file access 64-bit (uint64_t)

This changes the types of a big number of variables.

General rules:
- Using `uint64_t` in general. We also considered `int64_t` but eventually
  settled on keeping it unsigned, which is also closer to what one would expect
  with `size_t`/`off_t`.
- We only keep `int64_t` for `seek_end` (takes a negative offset from the end)
  and for the `Variant` bindings, since `Variant::INT` is `int64_t`. This means
  we only need to guard against passing negative values in `core_bind.cpp`.
- Using `uint32_t` integers for concepts not needing such a huge range, like
  pages, blocks, etc.

In addition:
- Improve usage of integer types in some related places; namely, `DirAccess`,
  core binds.

Note:
- On Windows, `_ftelli64` reports invalid values when using 32-bit MinGW with
  version < 8.0. This was an upstream bug fixed in 8.0. It breaks support for
  big files on 32-bit Windows builds made with that toolchain. We might add a
  workaround.

Fixes #44363.
Fixes godotengine/godot-proposals#400.

Co-authored-by: Rémi Verschelde <rverschelde@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/core/os/dir_access.h b/core/os/dir_access.h
index 7f0bcd372d..ec738d30d5 100644
--- a/core/os/dir_access.h
+++ b/core/os/dir_access.h
@@ -87,7 +87,7 @@ public:
 	virtual bool is_readable(String p_dir) { return true; };
 	virtual bool is_writable(String p_dir) { return true; };
 	static bool exists(String p_dir);
-	virtual size_t get_space_left() = 0;
+	virtual uint64_t get_space_left() = 0;
 
 	Error copy_dir(String p_from, String p_to, int p_chmod_flags = -1);
 	virtual Error copy(String p_from, String p_to, int p_chmod_flags = -1);