diff options
| -rw-r--r-- | core/encoding/varint/leb128.odin | 8 | ||||
| -rw-r--r-- | tests/core/encoding/varint/test_core_varint.odin | 62 |
2 files changed, 61 insertions, 9 deletions
diff --git a/core/encoding/varint/leb128.odin b/core/encoding/varint/leb128.odin index 7640ba1fb..898c6af67 100644 --- a/core/encoding/varint/leb128.odin +++ b/core/encoding/varint/leb128.odin @@ -10,6 +10,8 @@ // the LEB128 format as used by DWARF debug info, Android .dex and other file formats. package varint +import "core:fmt" + // 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`. @@ -29,6 +31,7 @@ decode_uleb128 :: proc(buf: []u8) -> (val: u128, size: int, err: Error) { for v, i in buf { size = i + 1 + // 18 * 7 bits = 126, which means that a possible 19th byte may at most be 0b0000_0011. if size == LEB128_MAX_BYTES && v > 0b0000_0011 { return 0, 0, .Value_Too_Large } @@ -60,8 +63,8 @@ decode_ileb128 :: proc(buf: []u8) -> (val: i128, size: int, err: Error) { for v in buf { size += 1 - // 18 * 7 bits = 126, which means that a possible 19th byte may at most be 0b0000_0011. - if size == LEB128_MAX_BYTES && v > 0b0000_0011 { + // 18 * 7 bits = 126, which including sign means we can have a 19th byte. + if size == LEB128_MAX_BYTES && v > 0x7f { return 0, 0, .Value_Too_Large } @@ -86,6 +89,7 @@ encode_uleb128 :: proc(buf: []u8, val: u128) -> (size: int, err: Error) { size += 1 if size > len(buf) { + fmt.println(val, buf[:size - 1]) return 0, .Buffer_Too_Small } diff --git a/tests/core/encoding/varint/test_core_varint.odin b/tests/core/encoding/varint/test_core_varint.odin index 63a9d1d72..813c52018 100644 --- a/tests/core/encoding/varint/test_core_varint.odin +++ b/tests/core/encoding/varint/test_core_varint.odin @@ -5,10 +5,13 @@ import "core:testing" import "core:fmt" import "core:os" import "core:slice" +import "core:math/rand" TEST_count := 0 TEST_fail := 0 +RANDOM_TESTS :: 100 + when ODIN_TEST { expect :: testing.expect log :: testing.log @@ -30,7 +33,7 @@ when ODIN_TEST { main :: proc() { t := testing.T{} - test_dwarf(&t) + test_leb128(&t) fmt.printf("%v/%v tests successful.\n", TEST_count - TEST_fail, TEST_count) if TEST_fail > 0 { @@ -39,7 +42,7 @@ main :: proc() { } @(test) -test_dwarf :: proc(t: ^testing.T) { +test_leb128 :: proc(t: ^testing.T) { buf: [varint.LEB128_MAX_BYTES]u8 for vector in ULEB_Vectors { @@ -75,6 +78,46 @@ test_dwarf :: proc(t: ^testing.T) { expect(t, size == vector.size && slice.simple_equal(vector.encoded, buf[:size]), msg) } } + + for num_bytes in 1..uint(16) { + for _ in 0..RANDOM_TESTS { + unsigned, signed := get_random(num_bytes) + + { + encode_size, encode_err := varint.encode_uleb128(buf[:], unsigned) + msg := fmt.tprintf("%v failed to encode as an unsigned LEB128 value, got %v", unsigned, encode_err) + expect(t, encode_err == .None, msg) + + decoded, decode_size, decode_err := varint.decode_uleb128(buf[:]) + msg = fmt.tprintf("Expected %02x to decode as %v, got %v", buf[:encode_size], unsigned, decoded) + expect(t, decode_err == .None && decode_size == encode_size && decoded == unsigned, msg) + } + + { + encode_size, encode_err := varint.encode_ileb128(buf[:], signed) + msg := fmt.tprintf("%v failed to encode as a signed LEB128 value, got %v", signed, encode_err) + expect(t, encode_err == .None, msg) + + decoded, decode_size, decode_err := varint.decode_ileb128(buf[:]) + msg = fmt.tprintf("Expected %02x to decode as %v, got %v, err: %v", buf[:encode_size], signed, decoded, decode_err) + expect(t, decode_err == .None && decode_size == encode_size && decoded == signed, msg) + } + } + } +} + +get_random :: proc(byte_count: uint) -> (u: u128, i: i128) { + assert(byte_count >= 0 && byte_count <= size_of(u128)) + + for _ in 1..byte_count { + u <<= 8 + u |= u128(rand.uint32() & 0xff) + } + + bias := i128(1 << (byte_count * 7)) - 1 + i = i128(u) - bias + + return } ULEB_Test_Vector :: struct { @@ -85,11 +128,13 @@ ULEB_Test_Vector :: struct { } ULEB_Vectors :: []ULEB_Test_Vector{ - { []u8{0x00}, 0, 1, .None }, - { []u8{0x7f}, 127, 1, .None }, - { []u8{0xE5, 0x8E, 0x26}, 624485, 3, .None }, - { []u8{0x80}, 0, 0, .Buffer_Too_Small }, - { []u8{}, 0, 0, .Buffer_Too_Small }, + { []u8{0x00}, 0, 1, .None }, + { []u8{0x7f}, 127, 1, .None }, + { []u8{0xE5, 0x8E, 0x26}, 624485, 3, .None }, + { []u8{0x80}, 0, 0, .Buffer_Too_Small }, + { []u8{}, 0, 0, .Buffer_Too_Small }, + + { []u8{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x03}, max(u128), 19, .None }, } ILEB_Test_Vector :: struct { @@ -105,4 +150,7 @@ ILEB_Vectors :: []ILEB_Test_Vector{ { []u8{0x40}, -64, 1, .None }, { []u8{0xC0, 0xBB, 0x78}, -123456, 3, .None }, { []u8{}, 0, 0, .Buffer_Too_Small }, + + { []u8{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x7e}, min(i128), 19, .None }, + { []u8{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01}, max(i128), 19, .None }, }
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