Merge branch 'master' into xml

8 files changed, 264 insertions, 43 deletions

diff --git a/core/encoding/hxa/doc.odin b/core/encoding/hxa/doc.odin
index 16b94a243..230d6ea66 100644
--- a/core/encoding/hxa/doc.odin
+++ b/core/encoding/hxa/doc.odin
@@ -27,7 +27,7 @@
 // 	Construction history, or BSP trees would make the format too large to serve its purpose.
 // 	The facilities of the formats to store meta data should make the format flexible enough
 // 	for most uses. Adding HxA support should be something anyone can do in a days work.
-
+//
 // Structure:
 // ----------
 // HxA is designed to be extremely simple to parse, and is therefore based around conventions. It has
@@ -45,17 +45,17 @@
 // of a number of named layers. All layers in the stack have the same number of elements. Each layer
 // describes one property of the primitive. Each layer can have multiple channels and each layer can
 // store data of a different type.
-
+//
 // HaX stores 3 kinds of nodes
 // 	- Pixel data.
 // 	- Polygon geometry data.
 // 	- Meta data only.
-
+//
 // Pixel Nodes stores pixels in a layer stack. A layer may store things like Albedo, Roughness,
 // Reflectance, Light maps, Masks, Normal maps, and Displacement. Layers use the channels of the
 // layers to store things like color. The length of the layer stack is determined by the type and
 // dimensions stored in the
-
+//
 // Geometry data is stored in 3 separate layer stacks for: vertex data, corner data and face data. The
 // vertex data stores things like verities, blend shapes, weight maps, and vertex colors. The first
 // layer in a vertex stack has to be a 3 channel layer named "position" describing the base position
@@ -63,7 +63,7 @@
 // for things like UV, normals, and adjacency. The first layer in a corner stack has to be a 1 channel
 // integer layer named "index" describing the vertices used to form polygons. The last value in each
 // polygon has a negative - 1 index to indicate the end of the polygon.
-
+//
 // Example:
 // 	A quad and a tri with the vertex index:
 // 		[0, 1, 2, 3] [1, 4, 2]
@@ -72,7 +72,7 @@
 // The face stack stores values per face. the length of the face stack has to match the number of
 // negative values in the index layer in the corner stack. The face stack can be used to store things
 // like material index.
-
+//
 // Storage
 // -------
 // All data is stored in little endian byte order with no padding. The layout mirrors the structs
diff --git a/core/encoding/hxa/read.odin b/core/encoding/hxa/read.odin
index ef7edc8b7..abe295530 100644
--- a/core/encoding/hxa/read.odin
+++ b/core/encoding/hxa/read.odin
@@ -39,6 +39,9 @@ read :: proc(data: []byte, filename := "<input>", print_error := false, allocato
 	read_value :: proc(r: ^Reader, $T: typeid) -> (value: T, err: Read_Error) {
 		remaining := len(r.data) - r.offset
 		if remaining < size_of(T) {
+			if r.print_error {
+				fmt.eprintf("file '%s' failed to read value at offset %v\n", r.filename, r.offset)
+			}
 			err = .Short_Read
 			return
 		}
@@ -51,6 +54,10 @@ read :: proc(data: []byte, filename := "<input>", print_error := false, allocato
 	read_array :: proc(r: ^Reader, $T: typeid, count: int) -> (value: []T, err: Read_Error) {
 		remaining := len(r.data) - r.offset
 		if remaining < size_of(T)*count {
+			if r.print_error {
+				fmt.eprintf("file '%s' failed to read array of %d elements at offset %v\n",
+							r.filename, count, r.offset)
+			}
 			err = .Short_Read
 			return
 		}
@@ -82,7 +89,8 @@ read :: proc(data: []byte, filename := "<input>", print_error := false, allocato
 			type := read_value(r, Meta_Value_Type) or_return
 			if type > max(Meta_Value_Type) {
 				if r.print_error {
-					fmt.eprintf("HxA Error: file '%s' has meta value type %d. Maximum value is ", r.filename, u8(type), u8(max(Meta_Value_Type)))
+					fmt.eprintf("HxA Error: file '%s' has meta value type %d. Maximum value is %d\n",
+								r.filename, u8(type), u8(max(Meta_Value_Type)))
 				}
 				err = .Invalid_Data
 				return
@@ -114,7 +122,8 @@ read :: proc(data: []byte, filename := "<input>", print_error := false, allocato
 			type := read_value(r, Layer_Data_Type) or_return
 			if type > max(type) {
 				if r.print_error {
-					fmt.eprintf("HxA Error: file '%s' has layer data type %d. Maximum value is ", r.filename, u8(type), u8(max(Layer_Data_Type)))
+					fmt.eprintf("HxA Error: file '%s' has layer data type %d. Maximum value is %d\n",
+								r.filename, u8(type), u8(max(Layer_Data_Type)))
 				}
 				err = .Invalid_Data
 				return
@@ -134,13 +143,23 @@ read :: proc(data: []byte, filename := "<input>", print_error := false, allocato
 	}
 
 	if len(data) < size_of(Header) {
+		if print_error {
+			fmt.eprintf("HxA Error: file '%s' has no header\n", filename)
+		}
+		err = .Short_Read
 		return
 	}
 
 	context.allocator = allocator
 
 	header := cast(^Header)raw_data(data)
-	assert(header.magic_number == MAGIC_NUMBER)
+	if (header.magic_number != MAGIC_NUMBER) {
+		if print_error {
+			fmt.eprintf("HxA Error: file '%s' has invalid magic number 0x%x\n", filename, header.magic_number)
+		}
+		err = .Invalid_Data
+		return
+	}
 
 	r := &Reader{
 		filename    = filename,
@@ -150,6 +169,7 @@ read :: proc(data: []byte, filename := "<input>", print_error := false, allocato
 	}
 
 	node_count := 0
+	file.header = header^
 	file.nodes = make([]Node, header.internal_node_count)
 	defer if err != nil {
 		nodes_destroy(file.nodes)
@@ -162,7 +182,8 @@ read :: proc(data: []byte, filename := "<input>", print_error := false, allocato
 		type := read_value(r, Node_Type) or_return
 		if type > max(Node_Type) {
 			if r.print_error {
-				fmt.eprintf("HxA Error: file '%s' has node type %d. Maximum value is ", r.filename, u8(type), u8(max(Node_Type)))
+				fmt.eprintf("HxA Error: file '%s' has node type %d. Maximum value is %d\n",
+							r.filename, u8(type), u8(max(Node_Type)))
 			}
 			err = .Invalid_Data
 			return
diff --git a/core/encoding/hxa/write.odin b/core/encoding/hxa/write.odin
index e774018b2..5bb950e81 100644
--- a/core/encoding/hxa/write.odin
+++ b/core/encoding/hxa/write.odin
@@ -84,7 +84,7 @@ write_internal :: proc(w: ^Writer, file: File) {
 
 	write_metadata :: proc(w: ^Writer, meta_data: []Meta) {
 		for m in meta_data {
-			name_len := max(len(m.name), 255)
+			name_len := min(len(m.name), 255)
 			write_value(w, u8(name_len))
 			write_string(w, m.name[:name_len])
 
@@ -127,7 +127,7 @@ write_internal :: proc(w: ^Writer, file: File) {
 	write_layer_stack :: proc(w: ^Writer, layers: Layer_Stack) {
 		write_value(w, u32(len(layers)))
 		for layer in layers {
-			name_len := max(len(layer.name), 255)
+			name_len := min(len(layer.name), 255)
 			write_value(w, u8(name_len))
 			write_string(w, layer .name[:name_len])
 
@@ -152,7 +152,7 @@ write_internal :: proc(w: ^Writer, file: File) {
 		return
 	}
 
-	write_value(w, &Header{
+	write_value(w, Header{
 		magic_number = MAGIC_NUMBER,
 		version = LATEST_VERSION,
 		internal_node_count = u32le(len(file.nodes)),
diff --git a/core/encoding/json/marshal.odin b/core/encoding/json/marshal.odin
index adbcb95be..9c54f35f0 100644
--- a/core/encoding/json/marshal.odin
+++ b/core/encoding/json/marshal.odin
@@ -8,17 +8,18 @@ import "core:strings"
 import "core:io"
 
 Marshal_Data_Error :: enum {
+	None,
 	Unsupported_Type,
 }
 
-Marshal_Error :: union {
+Marshal_Error :: union #shared_nil {
 	Marshal_Data_Error,
 	io.Error,
 }
 
 marshal :: proc(v: any, allocator := context.allocator) -> (data: []byte, err: Marshal_Error) {
 	b := strings.make_builder(allocator)
-	defer if err != .None {
+	defer if err != nil {
 		strings.destroy_builder(&b)
 	}
 
@@ -27,7 +28,7 @@ marshal :: proc(v: any, allocator := context.allocator) -> (data: []byte, err: M
 	if len(b.buf) != 0 {
 		data = b.buf[:]
 	}
-	return data, .None
+	return data, nil
 }
 
 marshal_to_builder :: proc(b: ^strings.Builder, v: any) -> Marshal_Error {
@@ -285,8 +286,8 @@ marshal_to_writer :: proc(w: io.Writer, v: any) -> (err: Marshal_Error) {
 			case runtime.Type_Info_Integer:
 				switch info.endianness {
 				case .Platform: return false
-				case .Little:   return ODIN_ENDIAN != "little"
-				case .Big:      return ODIN_ENDIAN != "big"
+				case .Little:   return ODIN_ENDIAN != .Little
+				case .Big:      return ODIN_ENDIAN != .Big
 				}
 			}
 			return false
diff --git a/core/encoding/json/parser.odin b/core/encoding/json/parser.odin
index c682ec9bd..7bf88c565 100644
--- a/core/encoding/json/parser.odin
+++ b/core/encoding/json/parser.odin
@@ -354,6 +354,12 @@ unquote_string :: proc(token: Token, spec: Specification, allocator := context.a
 
 	b := bytes_make(len(s) + 2*utf8.UTF_MAX, 1, allocator) or_return
 	w := copy(b, s[0:i])
+
+	if len(b) == 0 && allocator.data == nil {
+		// `unmarshal_count_array` calls us with a nil allocator
+		return string(b[:w]), nil
+	}
+
 	loop: for i < len(s) {
 		c := s[i]
 		switch {
diff --git a/core/encoding/json/unmarshal.odin b/core/encoding/json/unmarshal.odin
index fe3137b7e..bd48011f1 100644
--- a/core/encoding/json/unmarshal.odin
+++ b/core/encoding/json/unmarshal.odin
@@ -52,11 +52,11 @@ unmarshal_any :: proc(data: []byte, v: any, spec := DEFAULT_SPECIFICATION, alloc
 	if p.spec == .MJSON {
 		#partial switch p.curr_token.kind {
 		case .Ident, .String:
-			return unmarsal_object(&p, data, .EOF)
+			return unmarshal_object(&p, data, .EOF)
 		}
 	}
 
-	return unmarsal_value(&p, data)
+	return unmarshal_value(&p, data)
 }
 
 
@@ -148,7 +148,7 @@ assign_float :: proc(val: any, f: $T) -> bool {
 
 
 @(private)
-unmarsal_string :: proc(p: ^Parser, val: any, str: string, ti: ^reflect.Type_Info) -> bool {
+unmarshal_string_token :: proc(p: ^Parser, val: any, str: string, ti: ^reflect.Type_Info) -> bool {
 	val := val
 	switch dst in &val {
 	case string:
@@ -198,7 +198,7 @@ unmarsal_string :: proc(p: ^Parser, val: any, str: string, ti: ^reflect.Type_Inf
 
 
 @(private)
-unmarsal_value :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
+unmarshal_value :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
 	UNSUPPORTED_TYPE := Unsupported_Type_Error{v.id, p.curr_token}
 	token := p.curr_token
 	
@@ -257,7 +257,7 @@ unmarsal_value :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
 	case .Ident:
 		advance_token(p)
 		if p.spec == .MJSON {
-			if unmarsal_string(p, any{v.data, ti.id}, token.text, ti) {
+			if unmarshal_string_token(p, any{v.data, ti.id}, token.text, ti) {
 				return nil
 			}
 		}
@@ -266,7 +266,7 @@ unmarsal_value :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
 	case .String:
 		advance_token(p)
 		str := unquote_string(token, p.spec, p.allocator) or_return
-		if unmarsal_string(p, any{v.data, ti.id}, str, ti) {
+		if unmarshal_string_token(p, any{v.data, ti.id}, str, ti) {
 			return nil
 		}
 		delete(str, p.allocator)
@@ -274,10 +274,10 @@ unmarsal_value :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
 
 
 	case .Open_Brace:
-		return unmarsal_object(p, v, .Close_Brace)
+		return unmarshal_object(p, v, .Close_Brace)
 
 	case .Open_Bracket:
-		return unmarsal_array(p, v)
+		return unmarshal_array(p, v)
 
 	case:
 		if p.spec != .JSON {
@@ -312,16 +312,16 @@ unmarsal_value :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
 
 
 @(private)
-unmarsal_expect_token :: proc(p: ^Parser, kind: Token_Kind, loc := #caller_location) -> Token {
+unmarshal_expect_token :: proc(p: ^Parser, kind: Token_Kind, loc := #caller_location) -> Token {
 	prev := p.curr_token
 	err := expect_token(p, kind)
-	assert(err == nil, "unmarsal_expect_token")
+	assert(err == nil, "unmarshal_expect_token")
 	return prev
 }
 
 
 @(private)
-unmarsal_object :: proc(p: ^Parser, v: any, end_token: Token_Kind) -> (err: Unmarshal_Error) {
+unmarshal_object :: proc(p: ^Parser, v: any, end_token: Token_Kind) -> (err: Unmarshal_Error) {
 	UNSUPPORTED_TYPE := Unsupported_Type_Error{v.id, p.curr_token}
 	
 	if end_token == .Close_Brace {
@@ -342,7 +342,7 @@ unmarsal_object :: proc(p: ^Parser, v: any, end_token: Token_Kind) -> (err: Unma
 			key, _ := parse_object_key(p, p.allocator)
 			defer delete(key, p.allocator)
 			
-			unmarsal_expect_token(p, .Colon)						
+			unmarshal_expect_token(p, .Colon)						
 			
 			fields := reflect.struct_fields_zipped(ti.id)
 			
@@ -378,7 +378,7 @@ unmarsal_object :: proc(p: ^Parser, v: any, end_token: Token_Kind) -> (err: Unma
 				
 				field_ptr := rawptr(uintptr(v.data) + offset)
 				field := any{field_ptr, type.id}
-				unmarsal_value(p, field) or_return
+				unmarshal_value(p, field) or_return
 					
 				if parse_comma(p) {
 					break struct_loop
@@ -407,11 +407,11 @@ unmarsal_object :: proc(p: ^Parser, v: any, end_token: Token_Kind) -> (err: Unma
 		
 		map_loop: for p.curr_token.kind != end_token {
 			key, _ := parse_object_key(p, p.allocator)
-			unmarsal_expect_token(p, .Colon)
+			unmarshal_expect_token(p, .Colon)
 			
 			
 			mem.zero_slice(elem_backing)
-			if err := unmarsal_value(p, map_backing_value); err != nil {
+			if err := unmarshal_value(p, map_backing_value); err != nil {
 				delete(key, p.allocator)
 				return err
 			}
@@ -443,7 +443,7 @@ unmarsal_object :: proc(p: ^Parser, v: any, end_token: Token_Kind) -> (err: Unma
 	
 		enumerated_array_loop: for p.curr_token.kind != end_token {
 			key, _ := parse_object_key(p, p.allocator)
-			unmarsal_expect_token(p, .Colon)
+			unmarshal_expect_token(p, .Colon)
 			defer delete(key, p.allocator)
 
 			index := -1
@@ -460,7 +460,7 @@ unmarsal_object :: proc(p: ^Parser, v: any, end_token: Token_Kind) -> (err: Unma
 			index_ptr := rawptr(uintptr(v.data) + uintptr(index*t.elem_size))
 			index_any := any{index_ptr, t.elem.id}
 			
-			unmarsal_value(p, index_any) or_return
+			unmarshal_value(p, index_any) or_return
 			
 			if parse_comma(p) {
 				break enumerated_array_loop
@@ -480,10 +480,10 @@ unmarsal_object :: proc(p: ^Parser, v: any, end_token: Token_Kind) -> (err: Unma
 
 
 @(private)
-unmarsal_count_array :: proc(p: ^Parser) -> (length: uintptr) {
+unmarshal_count_array :: proc(p: ^Parser) -> (length: uintptr) {
 	p_backup := p^
 	p.allocator = mem.nil_allocator()
-	unmarsal_expect_token(p, .Open_Bracket)
+	unmarshal_expect_token(p, .Open_Bracket)
 	array_length_loop: for p.curr_token.kind != .Close_Bracket {
 		_, _ = parse_value(p)
 		length += 1
@@ -497,9 +497,9 @@ unmarsal_count_array :: proc(p: ^Parser) -> (length: uintptr) {
 }
 
 @(private)
-unmarsal_array :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
+unmarshal_array :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
 	assign_array :: proc(p: ^Parser, base: rawptr, elem: ^reflect.Type_Info, length: uintptr) -> Unmarshal_Error {
-		unmarsal_expect_token(p, .Open_Bracket)
+		unmarshal_expect_token(p, .Open_Bracket)
 		
 		for idx: uintptr = 0; p.curr_token.kind != .Close_Bracket; idx += 1 {
 			assert(idx < length)
@@ -507,14 +507,14 @@ unmarsal_array :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
 			elem_ptr := rawptr(uintptr(base) + idx*uintptr(elem.size))
 			elem := any{elem_ptr, elem.id}
 			
-			unmarsal_value(p, elem) or_return
+			unmarshal_value(p, elem) or_return
 			
 			if parse_comma(p) {
 				break
 			}	
 		}
 		
-		unmarsal_expect_token(p, .Close_Bracket)
+		unmarshal_expect_token(p, .Close_Bracket)
 		
 		
 		return nil
@@ -524,7 +524,7 @@ unmarsal_array :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
 	
 	ti := reflect.type_info_base(type_info_of(v.id))
 	
-	length := unmarsal_count_array(p)
+	length := unmarshal_count_array(p)
 	
 	#partial switch t in ti.variant {
 	case reflect.Type_Info_Slice:	
@@ -578,4 +578,4 @@ unmarsal_array :: proc(p: ^Parser, v: any) -> (err: Unmarshal_Error) {
 	}
 		
 	return UNSUPPORTED_TYPE
-}
\ No newline at end of file
+}
diff --git a/core/encoding/varint/doc.odin b/core/encoding/varint/doc.odin
new file mode 100644
index 000000000..5e4708a59
--- /dev/null
+++ b/core/encoding/varint/doc.odin
@@ -0,0 +1,28 @@
+/*
+	Implementation of the LEB128 variable integer encoding as used by DWARF encoding and DEX files, among others.
+
+	Author of this Odin package: Jeroen van Rijn
+
+	Example:
+	```odin
+	import "core:encoding/varint"
+	import "core:fmt"
+
+	main :: proc() {
+		buf: [varint.LEB128_MAX_BYTES]u8
+
+		value := u128(42)
+
+		encode_size, encode_err := varint.encode_uleb128(buf[:], value)
+		assert(encode_size == 1 && encode_err == .None)
+
+		fmt.printf("Encoded as %v\n", buf[:encode_size])
+		decoded_val, decode_size, decode_err := varint.decode_uleb128(buf[:])
+
+		assert(decoded_val == value && decode_size == encode_size && decode_err == .None)
+		fmt.printf("Decoded as %v, using %v byte%v\n", decoded_val, decode_size, "" if decode_size == 1 else "s")
+	}
+	```
+
+*/
+package varint
\ No newline at end of file
diff --git a/core/encoding/varint/leb128.odin b/core/encoding/varint/leb128.odin
new file mode 100644
index 000000000..f8fcc7de5
--- /dev/null
+++ b/core/encoding/varint/leb128.odin
@@ -0,0 +1,165 @@
+/*
+	Copyright 2022 Jeroen van Rijn <nom@duclavier.com>.
+	Made available under Odin's BSD-3 license.
+
+	List of contributors:
+		Jeroen van Rijn: Initial implementation.
+*/
+
+// package varint implements variable length integer encoding and decoding using
+// the LEB128 format as used by DWARF debug info, Android .dex and other file formats.
+package varint
+
+// In theory we should use the bigint package. In practice, varints bigger than this indicate a corrupted file.
+// Instead we'll set limits on the values we'll encode/decode
+// 18 * 7 bits = 126, which means that a possible 19th byte may at most be `0b0000_0011`.
+LEB128_MAX_BYTES    :: 19
+
+Error :: enum {
+	None             = 0,
+	Buffer_Too_Small = 1,
+	Value_Too_Large  = 2,
+}
+
+// Decode a slice of bytes encoding an unsigned LEB128 integer into value and number of bytes used.
+// Returns `size` == 0 for an invalid value, empty slice, or a varint > 18 bytes.
+decode_uleb128_buffer :: proc(buf: []u8) -> (val: u128, size: int, err: Error) {
+	if len(buf) == 0 {
+		return 0, 0, .Buffer_Too_Small
+	}
+
+	for v in buf {
+		val, size, err = decode_uleb128_byte(v, size, val)
+		if err != .Buffer_Too_Small {
+			return
+		}
+	}
+
+	if err == .Buffer_Too_Small {
+		val, size = 0, 0
+	}
+	return
+}
+
+// Decodes an unsigned LEB128 integer into value a byte at a time.
+// Returns `.None` when decoded properly, `.Value_Too_Large` when they value
+// exceeds the limits of a u128, and `.Buffer_Too_Small` when it's not yet fully decoded.
+decode_uleb128_byte :: proc(input: u8, offset: int, accumulator: u128) -> (val: u128, size: int, err: Error) {
+	size = offset + 1
+
+	// 18 * 7 bits = 126, which means that a possible 19th byte may at most be 0b0000_0011.
+	if size > LEB128_MAX_BYTES || size == LEB128_MAX_BYTES && input > 0b0000_0011 {
+		return 0, 0, .Value_Too_Large
+	}
+
+	val = accumulator | u128(input & 0x7f) << uint(offset * 7)
+
+	if input < 128 {
+		// We're done
+		return
+	}
+
+	// If the buffer runs out before the number ends, return an error.
+	return val, size, .Buffer_Too_Small
+}
+decode_uleb128 :: proc {decode_uleb128_buffer, decode_uleb128_byte}
+
+// Decode a slice of bytes encoding a signed LEB128 integer into value and number of bytes used.
+// Returns `size` == 0 for an invalid value, empty slice, or a varint > 18 bytes.
+decode_ileb128_buffer :: proc(buf: []u8) -> (val: i128, size: int, err: Error) {
+	if len(buf) == 0 {
+		return 0, 0, .Buffer_Too_Small
+	}
+
+	for v in buf {
+		val, size, err = decode_ileb128_byte(v, size, val)
+		if err != .Buffer_Too_Small {
+			return
+		}
+	}
+
+	if err == .Buffer_Too_Small {
+		val, size = 0, 0
+	}
+	return
+}
+
+// Decode a a signed LEB128 integer into value and number of bytes used, one byte at a time.
+// Returns `size` == 0 for an invalid value, empty slice, or a varint > 18 bytes.
+decode_ileb128_byte :: proc(input: u8, offset: int, accumulator: i128) -> (val: i128, size: int, err: Error) {
+	size = offset + 1
+	shift := uint(offset * 7)
+
+	// 18 * 7 bits = 126, which including sign means we can have a 19th byte.
+	if size > LEB128_MAX_BYTES || size == LEB128_MAX_BYTES && input > 0x7f {
+		return 0, 0, .Value_Too_Large
+	}
+
+	val = accumulator | i128(input & 0x7f) << shift
+
+	if input < 128 {
+		if input & 0x40 == 0x40 {
+			val |= max(i128) << (shift + 7)
+		}
+		return val, size, .None
+	}
+	return val, size, .Buffer_Too_Small
+}
+decode_ileb128 :: proc{decode_ileb128_buffer, decode_ileb128_byte}
+
+// Encode `val` into `buf` as an unsigned LEB128 encoded series of bytes.
+// `buf` must be appropriately sized.
+encode_uleb128 :: proc(buf: []u8, val: u128) -> (size: int, err: Error) {
+	val := val
+
+	for {
+		size += 1
+
+		if size > len(buf) {
+			return 0, .Buffer_Too_Small
+		}
+
+		low := val & 0x7f
+		val >>= 7
+
+		if val > 0 {
+			low |= 0x80 // more bytes to follow
+		}
+		buf[size - 1] = u8(low)
+
+		if val == 0 { break }
+	}
+	return
+}
+
+@(private)
+SIGN_MASK :: (i128(1) << 121) // sign extend mask
+
+// Encode `val` into `buf` as a signed LEB128 encoded series of bytes.
+// `buf` must be appropriately sized.
+encode_ileb128 :: proc(buf: []u8, val: i128) -> (size: int, err: Error) {
+	val      := val
+	more     := true
+
+	for more {
+		size += 1
+
+		if size > len(buf) {
+			return 0, .Buffer_Too_Small
+		}
+
+		low := val & 0x7f
+		val >>= 7
+
+		low = (low ~ SIGN_MASK) - SIGN_MASK
+
+		if (val == 0 && low & 0x40 != 0x40) || (val == -1 && low & 0x40 == 0x40) {
+			more = false
+		} else {
+			low |= 0x80
+		}
+
+		buf[size - 1] = u8(low)
+	}
+	return
+}
\ No newline at end of file