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>

3 files changed, 10 insertions, 10 deletions

diff --git a/scene/resources/resource_format_text.cpp b/scene/resources/resource_format_text.cpp
index f2751b7604..2414704a57 100644
--- a/scene/resources/resource_format_text.cpp
+++ b/scene/resources/resource_format_text.cpp
@@ -978,7 +978,7 @@ Error ResourceLoaderText::save_as_binary(FileAccess *p_f, const String &p_path)
 	}
 
 	wf->store_32(0); //string table size, will not be in use
-	size_t ext_res_count_pos = wf->get_position();
+	uint64_t ext_res_count_pos = wf->get_position();
 
 	wf->store_32(0); //zero ext resources, still parsing them
 
@@ -1041,7 +1041,7 @@ Error ResourceLoaderText::save_as_binary(FileAccess *p_f, const String &p_path)
 
 	//now, save resources to a separate file, for now
 
-	size_t sub_res_count_pos = wf->get_position();
+	uint64_t sub_res_count_pos = wf->get_position();
 	wf->store_32(0); //zero sub resources, still parsing them
 
 	String temp_file = p_path + ".temp";
@@ -1050,8 +1050,8 @@ Error ResourceLoaderText::save_as_binary(FileAccess *p_f, const String &p_path)
 		return ERR_CANT_OPEN;
 	}
 
-	Vector<size_t> local_offsets;
-	Vector<size_t> local_pointers_pos;
+	Vector<uint64_t> local_offsets;
+	Vector<uint64_t> local_pointers_pos;
 
 	while (next_tag.name == "sub_resource" || next_tag.name == "resource") {
 		String type;
@@ -1089,7 +1089,7 @@ Error ResourceLoaderText::save_as_binary(FileAccess *p_f, const String &p_path)
 		wf->store_64(0); //temp local offset
 
 		bs_save_unicode_string(wf2, type);
-		size_t propcount_ofs = wf2->get_position();
+		uint64_t propcount_ofs = wf2->get_position();
 		wf2->store_32(0);
 
 		int prop_count = 0;
@@ -1159,7 +1159,7 @@ Error ResourceLoaderText::save_as_binary(FileAccess *p_f, const String &p_path)
 
 		local_offsets.push_back(wf2->get_position());
 		bs_save_unicode_string(wf2, "PackedScene");
-		size_t propcount_ofs = wf2->get_position();
+		uint64_t propcount_ofs = wf2->get_position();
 		wf2->store_32(0);
 
 		int prop_count = 0;
@@ -1185,7 +1185,7 @@ Error ResourceLoaderText::save_as_binary(FileAccess *p_f, const String &p_path)
 
 	wf2->close();
 
-	size_t offset_from = wf->get_position();
+	uint64_t offset_from = wf->get_position();
 	wf->seek(sub_res_count_pos); //plus one because the saved one
 	wf->store_32(local_offsets.size());
 
diff --git a/scene/resources/text_file.cpp b/scene/resources/text_file.cpp
index cf07003720..b71909b6bb 100644
--- a/scene/resources/text_file.cpp
+++ b/scene/resources/text_file.cpp
@@ -55,10 +55,10 @@ Error TextFile::load_text(const String &p_path) {
 
 	ERR_FAIL_COND_V_MSG(err, err, "Cannot open TextFile '" + p_path + "'.");
 
-	int len = f->get_len();
+	uint64_t len = f->get_len();
 	sourcef.resize(len + 1);
 	uint8_t *w = sourcef.ptrw();
-	int r = f->get_buffer(w, len);
+	uint64_t r = f->get_buffer(w, len);
 	f->close();
 	memdelete(f);
 	ERR_FAIL_COND_V(r != len, ERR_CANT_OPEN);
diff --git a/scene/resources/texture.cpp b/scene/resources/texture.cpp
index 624eae0411..1b2176d30a 100644
--- a/scene/resources/texture.cpp
+++ b/scene/resources/texture.cpp
@@ -335,7 +335,7 @@ Ref<Image> StreamTexture2D::load_image_from_file(FileAccess *f, int p_size_limit
 
 		//mipmaps need to be read independently, they will be later combined
 		Vector<Ref<Image>> mipmap_images;
-		int total_size = 0;
+		uint64_t total_size = 0;
 
 		bool first = true;