[varint] Add LEB128 decoding + tests

Also make tests in general less spammy: Don't print [PASS] for each successful test, only report failures and progress.

core/encoding/varint/leb128.odin

@@ -0,0 +1,67 @@
+/*
+	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 and other file formats
+package varint
+
+// 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 > 16 bytes.
+// In theory we should use the bigint package. In practice, varints bigger than this indicate a corrupted file.
+decode_uleb128 :: proc(buf: []u8) -> (val: u128, size: int) {
+	more := true
+
+	for v, i in buf {
+		size = i + 1
+
+		if size > size_of(u128) {
+			return
+		}
+
+		val |= u128(v & 0x7f) << uint(i * 7)
+
+		if v < 128 {
+			more = false
+			break
+		}
+	}
+
+	// If the buffer runs out before the number ends, return an error.
+	if more {
+		return 0, 0
+	}
+	return
+}
+
+// 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 > 16 bytes.
+// In theory we should use the bigint package. In practice, varints bigger than this indicate a corrupted file.
+decode_ileb128 :: proc(buf: []u8) -> (val: i128, size: int) {
+	shift: uint
+
+	if len(buf) == 0 {
+		return
+	}
+
+	for v in buf {
+		size += 1
+		if size > size_of(i128) {
+			return
+		}
+
+		val |= i128(v & 0x7f) << shift
+		shift += 7
+
+		if v < 128 { break }
+	}
+
+	if buf[size - 1] & 0x40 == 0x40 {
+		val |= max(i128) << shift
+	}
+	return
+}

tests/core/Makefile

@@ -1,7 +1,7 @@
 ODIN=../../odin
 PYTHON=$(shell which python3)
 
-all: download_test_assets image_test compress_test strings_test hash_test crypto_test noise_test
+all: download_test_assets image_test compress_test strings_test hash_test crypto_test noise_test encoding_test
 
 download_test_assets:
 	$(PYTHON) download_assets.py
@@ -23,3 +23,7 @@ crypto_test:
 
 noise_test:
 	$(ODIN) run math/noise -out=test_noise
+
+encoding_test:
+	$(ODIN) run encoding/json -out=test_json
+	$(ODIN) run encoding/varint -out=test_varint

tests/core/build.bat

@@ -35,7 +35,8 @@ echo ---
 echo ---
 echo Running core:encoding tests
 echo ---
-%PATH_TO_ODIN% run encoding %COMMON%
+%PATH_TO_ODIN% run encoding/json %COMMON%
+%PATH_TO_ODIN% run encoding/varint %COMMON%
 
 echo ---
 echo Running core:math/noise tests

tests/core/compress/test_core_compress.odin

@@ -30,14 +30,12 @@ when ODIN_TEST {
 	log     :: testing.log
 } else {
 	expect  :: proc(t: ^testing.T, condition: bool, message: string, loc := #caller_location) {
-		fmt.printf("[%v] ", loc)
 		TEST_count += 1
 		if !condition {
 			TEST_fail += 1
-			fmt.println(message)
+			fmt.printf("[%v] %v\n", loc, message)
 			return
 		}
-		fmt.println(" PASS")
 	}
 	log     :: proc(t: ^testing.T, v: any, loc := #caller_location) {
 		fmt.printf("[%v] ", loc)

tests/core/crypto/test_core_crypto.odin

@@ -47,14 +47,12 @@ when ODIN_TEST {
 	log     :: testing.log
 } else {
 	expect  :: proc(t: ^testing.T, condition: bool, message: string, loc := #caller_location) {
-        fmt.printf("[%v] ", loc)
 		TEST_count += 1
 		if !condition {
 			TEST_fail += 1
-            fmt.println(message)
+			fmt.printf("[%v] %v\n", loc, message)
 			return
 		}
-        fmt.println(" PASS")
 	}
 	log :: proc(t: ^testing.T, v: any, loc := #caller_location) {
 		fmt.printf("[%v] ", loc)

tests/core/encoding/json/test_core_json.odin

@@ -13,14 +13,12 @@ when ODIN_TEST {
 	log     :: testing.log
 } else {
 	expect  :: proc(t: ^testing.T, condition: bool, message: string, loc := #caller_location) {
-        fmt.printf("[%v] ", loc)
 		TEST_count += 1
 		if !condition {
 			TEST_fail += 1
-            fmt.println(message)
+			fmt.printf("[%v] %v\n", loc, message)
 			return
 		}
-        fmt.println(" PASS")
 	}
 	log     :: proc(t: ^testing.T, v: any, loc := #caller_location) {
 		fmt.printf("[%v] ", loc)

tests/core/encoding/varint/test_core_varint.odin

@@ -0,0 +1,81 @@
+package test_core_varint
+
+import "core:encoding/varint"
+import "core:testing"
+import "core:fmt"
+import "core:os"
+
+TEST_count := 0
+TEST_fail  := 0
+
+when ODIN_TEST {
+	expect  :: testing.expect
+	log     :: testing.log
+} else {
+	expect  :: proc(t: ^testing.T, condition: bool, message: string, loc := #caller_location) {
+		TEST_count += 1
+		if !condition {
+			TEST_fail += 1
+			fmt.printf("[%v] %v\n", loc, message)
+			return
+		}
+	}
+	log     :: proc(t: ^testing.T, v: any, loc := #caller_location) {
+		fmt.printf("[%v] ", loc)
+		fmt.printf("log: %v\n", v)
+	}
+}
+
+main :: proc() {
+	t := testing.T{}
+
+	test_dwarf(&t)
+
+	fmt.printf("%v/%v tests successful.\n", TEST_count - TEST_fail, TEST_count)
+	if TEST_fail > 0 {
+		os.exit(1)
+	}
+}
+
+@(test)
+test_dwarf :: proc(t: ^testing.T) {
+	for vector in ULEB_Vectors {
+		val, size := varint.decode_uleb128(vector.encoded)
+
+		msg := fmt.tprintf("Expected %02x to decode to %v consuming %v bytes, got %v and %v", vector.encoded, vector.value, vector.size, val, size)
+		expect(t, size == vector.size && val == vector.value, msg)
+	}
+
+	for vector in ILEB_Vectors {
+		val, size := varint.decode_ileb128(vector.encoded)
+
+		msg := fmt.tprintf("Expected %02x to decode to %v consuming %v bytes, got %v and %v", vector.encoded, vector.value, vector.size, val, size)
+		expect(t, size == vector.size && val == vector.value, msg)
+	}
+}
+
+ULEB_Test_Vector :: struct {
+	encoded: []u8,
+	value:   u128,
+	size:    int,
+}
+
+ULEB_Vectors :: []ULEB_Test_Vector{
+	{ []u8{0x00},             0,      1 },
+    { []u8{0x7f},             127,    1 },
+	{ []u8{0xE5, 0x8E, 0x26}, 624485, 3 },
+    { []u8{0x80},             0,      0 },
+    { []u8{},                 0,      0 },
+}
+
+ILEB_Test_Vector :: struct {
+	encoded: []u8,
+	value:   i128,
+	size:    int,
+}
+
+ILEB_Vectors :: []ILEB_Test_Vector{
+	{ []u8{0x00},             0,       1 },
+	{ []u8{0xC0, 0xBB, 0x78}, -123456, 3 },
+    { []u8{},                 0,       0 },
+}

tests/core/hash/test_core_hash.odin

@@ -15,14 +15,12 @@ when ODIN_TEST {
 	log     :: testing.log
 } else {
 	expect  :: proc(t: ^testing.T, condition: bool, message: string, loc := #caller_location) {
-		fmt.printf("[%v] ", loc)
 		TEST_count += 1
 		if !condition {
 			TEST_fail += 1
-			fmt.println(" FAIL:", message)
+			fmt.printf("[%v] %v\n", loc, message)
 			return
 		}
-		fmt.println(" PASS")
 	}
 	log     :: proc(t: ^testing.T, v: any, loc := #caller_location) {
 		fmt.printf("[%v] ", loc)

tests/core/image/test_core_image.odin

@@ -36,14 +36,12 @@ when ODIN_TEST {
 	log     :: testing.log
 } else {
 	expect  :: proc(t: ^testing.T, condition: bool, message: string, loc := #caller_location) {
-        fmt.printf("[%v] ", loc)
 		TEST_count += 1
 		if !condition {
 			TEST_fail += 1
-            fmt.println(message)
+			fmt.printf("[%v] %v\n", loc, message)
 			return
 		}
-        fmt.println(" PASS")
 	}
 	log     :: proc(t: ^testing.T, v: any, loc := #caller_location) {
 		fmt.printf("[%v] ", loc)

tests/core/math/noise/test_core_math_noise.odin

@@ -17,14 +17,12 @@ when ODIN_TEST {
 	log     :: testing.log
 } else {
 	expect  :: proc(t: ^testing.T, condition: bool, message: string, loc := #caller_location) {
-        fmt.printf("[%v] ", loc)
 		TEST_count += 1
 		if !condition {
 			TEST_fail += 1
-            fmt.println(message)
+			fmt.printf("[%v] %v\n", loc, message)
 			return
 		}
-        fmt.println(" PASS")
 	}
 	log     :: proc(t: ^testing.T, v: any, loc := #caller_location) {
 		fmt.printf("[%v] ", loc)

tests/core/odin/test_parser.odin

@@ -14,14 +14,12 @@ when ODIN_TEST {
 	log     :: testing.log
 } else {
 	expect  :: proc(t: ^testing.T, condition: bool, message: string, loc := #caller_location) {
-        fmt.printf("[%v] ", loc)
 		TEST_count += 1
 		if !condition {
 			TEST_fail += 1
-            fmt.println(message)
+			fmt.printf("[%v] %v\n", loc, message)
 			return
 		}
-        fmt.println(" PASS")
 	}
 	log     :: proc(t: ^testing.T, v: any, loc := #caller_location) {
 		fmt.printf("[%v] ", loc)
@@ -29,7 +27,6 @@ when ODIN_TEST {
 	}
 }
 
-
 main :: proc() {
 	t := testing.T{}
 	test_parse_demo(&t)

tests/core/strings/test_core_strings.odin

@@ -13,14 +13,12 @@ when ODIN_TEST {
 	log     :: testing.log
 } else {
 	expect  :: proc(t: ^testing.T, condition: bool, message: string, loc := #caller_location) {
-        fmt.printf("[%v] ", loc)
 		TEST_count += 1
 		if !condition {
 			TEST_fail += 1
-            fmt.println(message)
+			fmt.printf("[%v] %v\n", loc, message)
 			return
 		}
-        fmt.println(" PASS")
 	}
 	log     :: proc(t: ^testing.T, v: any, loc := #caller_location) {
 		fmt.printf("[%v] ", loc)