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, 16 insertions, 16 deletions

diff --git a/drivers/windows/file_access_windows.cpp b/drivers/windows/file_access_windows.cpp
index b1b3fc9092..0f52c70482 100644
--- a/drivers/windows/file_access_windows.cpp
+++ b/drivers/windows/file_access_windows.cpp
@@ -193,10 +193,11 @@ bool FileAccessWindows::is_open() const {
 	return (f != nullptr);
 }
 
-void FileAccessWindows::seek(size_t p_position) {
+void FileAccessWindows::seek(uint64_t p_position) {
 	ERR_FAIL_COND(!f);
+
 	last_error = OK;
-	if (fseek(f, p_position, SEEK_SET)) {
+	if (_fseeki64(f, p_position, SEEK_SET)) {
 		check_errors();
 	}
 	prev_op = 0;
@@ -204,28 +205,27 @@ void FileAccessWindows::seek(size_t p_position) {
 
 void FileAccessWindows::seek_end(int64_t p_position) {
 	ERR_FAIL_COND(!f);
-	if (fseek(f, p_position, SEEK_END)) {
+	if (_fseeki64(f, p_position, SEEK_END)) {
 		check_errors();
 	}
 	prev_op = 0;
 }
 
-size_t FileAccessWindows::get_position() const {
-	size_t aux_position = 0;
-	aux_position = ftell(f);
-	if (!aux_position) {
+uint64_t FileAccessWindows::get_position() const {
+	int64_t aux_position = _ftelli64(f);
+	if (aux_position < 0) {
 		check_errors();
 	}
 	return aux_position;
 }
 
-size_t FileAccessWindows::get_len() const {
+uint64_t FileAccessWindows::get_len() const {
 	ERR_FAIL_COND_V(!f, 0);
 
-	size_t pos = get_position();
-	fseek(f, 0, SEEK_END);
-	int size = get_position();
-	fseek(f, pos, SEEK_SET);
+	uint64_t pos = get_position();
+	_fseeki64(f, 0, SEEK_END);
+	uint64_t size = get_position();
+	_fseeki64(f, pos, SEEK_SET);
 
 	return size;
 }
@@ -252,17 +252,17 @@ uint8_t FileAccessWindows::get_8() const {
 	return b;
 }
 
-int FileAccessWindows::get_buffer(uint8_t *p_dst, int p_length) const {
+uint64_t FileAccessWindows::get_buffer(uint8_t *p_dst, uint64_t p_length) const {
 	ERR_FAIL_COND_V(!p_dst && p_length > 0, -1);
-	ERR_FAIL_COND_V(p_length < 0, -1);
 	ERR_FAIL_COND_V(!f, -1);
+
 	if (flags == READ_WRITE || flags == WRITE_READ) {
 		if (prev_op == WRITE) {
 			fflush(f);
 		}
 		prev_op = READ;
 	}
-	int read = fread(p_dst, 1, p_length, f);
+	uint64_t read = fread(p_dst, 1, p_length, f);
 	check_errors();
 	return read;
 };
@@ -292,7 +292,7 @@ void FileAccessWindows::store_8(uint8_t p_dest) {
 	fwrite(&p_dest, 1, 1, f);
 }
 
-void FileAccessWindows::store_buffer(const uint8_t *p_src, int p_length) {
+void FileAccessWindows::store_buffer(const uint8_t *p_src, uint64_t p_length) {
 	ERR_FAIL_COND(!f);
 	if (flags == READ_WRITE || flags == WRITE_READ) {
 		if (prev_op == READ) {