[wasm] Add support and unittests for decoding signed LEB128.

test/unittests/wasm/decoder-unittest.cc

Index: test/unittests/wasm/decoder-unittest.cc
diff --git a/test/unittests/wasm/decoder-unittest.cc b/test/unittests/wasm/decoder-unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..de6bf49ea855fd5aa07ae27b7f0ca4971c967558
--- /dev/null
+++ b/test/unittests/wasm/decoder-unittest.cc
@@ -0,0 +1,413 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "test/unittests/test-utils.h"
+
+#include "src/wasm/decoder.h"
+#include "src/wasm/wasm-macro-gen.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+class DecoderTest : public TestWithZone {
+ public:
+  DecoderTest() : decoder(nullptr, nullptr) {}
+
+  Decoder decoder;
+};
+
+#define CHECK_UINT32V_INLINE(expected, expected_length, ...)           \
+  do {                                                                 \
+    const byte data[] = {__VA_ARGS__};                                 \
+    decoder.Reset(data, data + sizeof(data));                          \
+    int length;                                                        \
+    EXPECT_EQ(expected,                                                \
+              decoder.checked_read_u32v(decoder.start(), 0, &length)); \
+    EXPECT_EQ(expected_length, length);                                \
+  } while (false)
+
+#define CHECK_INT32V_INLINE(expected, expected_length, ...)            \
+  do {                                                                 \
+    const byte data[] = {__VA_ARGS__};                                 \
+    decoder.Reset(data, data + sizeof(data));                          \
+    int length;                                                        \
+    EXPECT_EQ(expected,                                                \
+              decoder.checked_read_i32v(decoder.start(), 0, &length)); \
+    EXPECT_EQ(expected_length, length);                                \
+  } while (false)
+
+TEST_F(DecoderTest, ReadU32v_OneByte) {
+  CHECK_UINT32V_INLINE(0, 1, 0);
+  CHECK_UINT32V_INLINE(5, 1, 5);
+  CHECK_UINT32V_INLINE(7, 1, 7);
+  CHECK_UINT32V_INLINE(9, 1, 9);
+  CHECK_UINT32V_INLINE(37, 1, 37);
+  CHECK_UINT32V_INLINE(69, 1, 69);
+  CHECK_UINT32V_INLINE(110, 1, 110);
+  CHECK_UINT32V_INLINE(125, 1, 125);
+  CHECK_UINT32V_INLINE(126, 1, 126);
+  CHECK_UINT32V_INLINE(127, 1, 127);
+}
+
+TEST_F(DecoderTest, ReadU32v_TwoByte) {
+  CHECK_UINT32V_INLINE(0, 1, 0, 0);

[ahaas, 2016/02/29 08:51:41]

Why don't you use U32V_2 also here?

[titzer, 2016/02/29 16:51:46]

I wanted to have one or two tests that don't go through the macros as well.

+  CHECK_UINT32V_INLINE(10, 1, 10, 0);
+  CHECK_UINT32V_INLINE(27, 1, 27, 0);
+  CHECK_UINT32V_INLINE(100, 1, 100, 0);
+
+  CHECK_UINT32V_INLINE(444, 2, U32V_2(444));
+  CHECK_UINT32V_INLINE(544, 2, U32V_2(544));
+  CHECK_UINT32V_INLINE(1311, 2, U32V_2(1311));
+  CHECK_UINT32V_INLINE(2333, 2, U32V_2(2333));
+
+  for (uint32_t i = 0; i < 1 << 14; i = i * 13 + 1) {
+    CHECK_UINT32V_INLINE(i, 2, U32V_2(i));
+  }
+
+  const uint32_t max = (1 << 14) - 1;
+  CHECK_UINT32V_INLINE(max, 2, U32V_2(max));
+}
+
+TEST_F(DecoderTest, ReadU32v_ThreeByte) {
+  CHECK_UINT32V_INLINE(0, 1, 0, 0, 0, 0);
+  CHECK_UINT32V_INLINE(10, 1, 10, 0, 0, 0);
+  CHECK_UINT32V_INLINE(27, 1, 27, 0, 0, 0);
+  CHECK_UINT32V_INLINE(100, 1, 100, 0, 0, 0);
+
+  CHECK_UINT32V_INLINE(11, 3, U32V_3(11));
+  CHECK_UINT32V_INLINE(101, 3, U32V_3(101));
+  CHECK_UINT32V_INLINE(446, 3, U32V_3(446));
+  CHECK_UINT32V_INLINE(546, 3, U32V_3(546));
+  CHECK_UINT32V_INLINE(1319, 3, U32V_3(1319));
+  CHECK_UINT32V_INLINE(2338, 3, U32V_3(2338));
+  CHECK_UINT32V_INLINE(8191, 3, U32V_3(8191));
+  CHECK_UINT32V_INLINE(9999, 3, U32V_3(9999));
+  CHECK_UINT32V_INLINE(14444, 3, U32V_3(14444));
+  CHECK_UINT32V_INLINE(314444, 3, U32V_3(314444));
+  CHECK_UINT32V_INLINE(614444, 3, U32V_3(614444));
+
+  const uint32_t max = (1 << 21) - 1;
+
+  for (uint32_t i = 0; i <= max; i = i * 13 + 3) {
+    CHECK_UINT32V_INLINE(i, 3, U32V_3(i), 0);
+  }
+
+  CHECK_UINT32V_INLINE(max, 3, U32V_3(max));
+}
+
+TEST_F(DecoderTest, ReadU32v_FourByte) {
+  CHECK_UINT32V_INLINE(0, 1, 0, 0, 0, 0, 0);
+  CHECK_UINT32V_INLINE(10, 1, 10, 0, 0, 0, 0);
+  CHECK_UINT32V_INLINE(27, 1, 27, 0, 0, 0, 0);
+  CHECK_UINT32V_INLINE(100, 1, 100, 0, 0, 0, 0);
+
+  CHECK_UINT32V_INLINE(13, 4, U32V_4(13));
+  CHECK_UINT32V_INLINE(107, 4, U32V_4(107));
+  CHECK_UINT32V_INLINE(449, 4, U32V_4(449));
+  CHECK_UINT32V_INLINE(541, 4, U32V_4(541));
+  CHECK_UINT32V_INLINE(1317, 4, U32V_4(1317));
+  CHECK_UINT32V_INLINE(2334, 4, U32V_4(2334));
+  CHECK_UINT32V_INLINE(8191, 4, U32V_4(8191));
+  CHECK_UINT32V_INLINE(9994, 4, U32V_4(9994));
+  CHECK_UINT32V_INLINE(14442, 4, U32V_4(14442));
+  CHECK_UINT32V_INLINE(314442, 4, U32V_4(314442));
+  CHECK_UINT32V_INLINE(614442, 4, U32V_4(614442));
+  CHECK_UINT32V_INLINE(1614442, 4, U32V_4(1614442));
+  CHECK_UINT32V_INLINE(5614442, 4, U32V_4(5614442));
+  CHECK_UINT32V_INLINE(19614442, 4, U32V_4(19614442));
+
+  const uint32_t max = (1 << 28) - 1;
+
+  for (uint32_t i = 0; i <= max; i = i * 13 + 5) {
+    CHECK_UINT32V_INLINE(i, 4, U32V_4(i), 0);
+  }
+
+  CHECK_UINT32V_INLINE(max, 4, U32V_4(max));
+}
+
+TEST_F(DecoderTest, ReadU32v_FiveByte) {
+  CHECK_UINT32V_INLINE(0, 1, 0, 0, 0, 0, 0);
+  CHECK_UINT32V_INLINE(10, 1, 10, 0, 0, 0, 0);
+  CHECK_UINT32V_INLINE(27, 1, 27, 0, 0, 0, 0);
+  CHECK_UINT32V_INLINE(100, 1, 100, 0, 0, 0, 0);
+
+  CHECK_UINT32V_INLINE(13, 5, U32V_5(13));
+  CHECK_UINT32V_INLINE(107, 5, U32V_5(107));
+  CHECK_UINT32V_INLINE(449, 5, U32V_5(449));
+  CHECK_UINT32V_INLINE(541, 5, U32V_5(541));
+  CHECK_UINT32V_INLINE(1317, 5, U32V_5(1317));
+  CHECK_UINT32V_INLINE(2334, 5, U32V_5(2334));
+  CHECK_UINT32V_INLINE(8191, 5, U32V_5(8191));
+  CHECK_UINT32V_INLINE(9994, 5, U32V_5(9994));
+  CHECK_UINT32V_INLINE(24442, 5, U32V_5(24442));
+  CHECK_UINT32V_INLINE(414442, 5, U32V_5(414442));
+  CHECK_UINT32V_INLINE(714442, 5, U32V_5(714442));
+  CHECK_UINT32V_INLINE(1614442, 5, U32V_5(1614442));
+  CHECK_UINT32V_INLINE(6614442, 5, U32V_5(6614442));
+  CHECK_UINT32V_INLINE(89614442, 5, U32V_5(89614442));
+  CHECK_UINT32V_INLINE(2219614442u, 5, U32V_5(2219614442u));
+  CHECK_UINT32V_INLINE(3219614442u, 5, U32V_5(3219614442u));
+  CHECK_UINT32V_INLINE(4019614442u, 5, U32V_5(4019614442u));
+
+  const uint32_t max = 0xFFFFFFFFu;
+
+  for (uint32_t i = 1; i < 32; i++) {
+    uint32_t val = 0x983489aau << i;
+    CHECK_UINT32V_INLINE(val, 5, U32V_5(val), 0);
+  }
+
+  CHECK_UINT32V_INLINE(max, 5, U32V_5(max));
+}
+
+TEST_F(DecoderTest, ReadU32v_various) {
+  for (int i = 0; i < 10; i++) {
+    uint32_t x = 0xCCCCCCCCu * i;
+    for (int width = 0; width < 32; width++) {
+      uint32_t val = x >> width;
+
+      CHECK_UINT32V_INLINE(val & MASK_7, 1, U32V_1(val));

[bradn, 2016/02/29 06:30:00]

These masks are only used for this test. They might be clearer if inline with
the test?

+      CHECK_UINT32V_INLINE(val & MASK_14, 2, U32V_2(val));
+      CHECK_UINT32V_INLINE(val & MASK_21, 3, U32V_3(val));
+      CHECK_UINT32V_INLINE(val & MASK_28, 4, U32V_4(val));
+      CHECK_UINT32V_INLINE(val, 5, U32V_5(val));
+    }
+  }
+}
+
+TEST_F(DecoderTest, ReadI32v_OneByte) {
+  CHECK_INT32V_INLINE(0, 1, 0);
+  CHECK_INT32V_INLINE(4, 1, 4);
+  CHECK_INT32V_INLINE(6, 1, 6);
+  CHECK_INT32V_INLINE(9, 1, 9);
+  CHECK_INT32V_INLINE(33, 1, 33);
+  CHECK_INT32V_INLINE(61, 1, 61);
+  CHECK_INT32V_INLINE(63, 1, 63);
+
+  CHECK_INT32V_INLINE(-1, 1, 127);
+  CHECK_INT32V_INLINE(-2, 1, 126);
+  CHECK_INT32V_INLINE(-11, 1, 117);
+  CHECK_INT32V_INLINE(-62, 1, 66);
+  CHECK_INT32V_INLINE(-63, 1, 65);
+  CHECK_INT32V_INLINE(-64, 1, 64);
+}
+
+TEST_F(DecoderTest, ReadI32v_TwoByte) {
+  CHECK_INT32V_INLINE(0, 2, U32V_2(0));
+  CHECK_INT32V_INLINE(9, 2, U32V_2(9));
+  CHECK_INT32V_INLINE(61, 2, U32V_2(61));
+  CHECK_INT32V_INLINE(63, 2, U32V_2(63));
+
+  CHECK_INT32V_INLINE(-1, 2, U32V_2(-1));
+  CHECK_INT32V_INLINE(-2, 2, U32V_2(-2));
+  CHECK_INT32V_INLINE(-63, 2, U32V_2(-63));
+  CHECK_INT32V_INLINE(-64, 2, U32V_2(-64));
+
+  CHECK_INT32V_INLINE(-200, 2, U32V_2(-200));
+  CHECK_INT32V_INLINE(-1002, 2, U32V_2(-1002));
+  CHECK_INT32V_INLINE(-2004, 2, U32V_2(-2004));
+  CHECK_INT32V_INLINE(-4077, 2, U32V_2(-4077));
+
+  CHECK_INT32V_INLINE(207, 2, U32V_2(207));
+  CHECK_INT32V_INLINE(1009, 2, U32V_2(1009));
+  CHECK_INT32V_INLINE(2003, 2, U32V_2(2003));
+  CHECK_INT32V_INLINE(4072, 2, U32V_2(4072));
+
+  const int32_t min = 0 - (1 << 13);
+  for (int i = min; i < min + 10; i++) {
+    CHECK_INT32V_INLINE(i, 2, U32V_2(i));
+  }
+
+  const int32_t max = (1 << 13) - 1;
+  for (int i = max; i > max - 10; i--) {
+    CHECK_INT32V_INLINE(i, 2, U32V_2(i));
+  }
+}
+
+TEST_F(DecoderTest, ReadI32v_ThreeByte) {
+  CHECK_INT32V_INLINE(0, 3, U32V_3(0));
+  CHECK_INT32V_INLINE(9, 3, U32V_3(9));
+  CHECK_INT32V_INLINE(61, 3, U32V_3(61));
+  CHECK_INT32V_INLINE(63, 3, U32V_3(63));
+
+  CHECK_INT32V_INLINE(-1, 3, U32V_3(-1));
+  CHECK_INT32V_INLINE(-2, 3, U32V_3(-2));
+  CHECK_INT32V_INLINE(-63, 3, U32V_3(-63));
+  CHECK_INT32V_INLINE(-64, 3, U32V_3(-64));
+
+  CHECK_INT32V_INLINE(-207, 3, U32V_3(-207));
+  CHECK_INT32V_INLINE(-1012, 3, U32V_3(-1012));
+  CHECK_INT32V_INLINE(-4067, 3, U32V_3(-4067));
+  CHECK_INT32V_INLINE(-14067, 3, U32V_3(-14067));
+  CHECK_INT32V_INLINE(-234061, 3, U32V_3(-234061));
+
+  CHECK_INT32V_INLINE(237, 3, U32V_3(237));
+  CHECK_INT32V_INLINE(1309, 3, U32V_3(1309));
+  CHECK_INT32V_INLINE(4372, 3, U32V_3(4372));
+  CHECK_INT32V_INLINE(64372, 3, U32V_3(64372));
+  CHECK_INT32V_INLINE(374372, 3, U32V_3(374372));
+
+  const int32_t min = 0 - (1 << 20);
+  for (int i = min; i < min + 10; i++) {
+    CHECK_INT32V_INLINE(i, 3, U32V_3(i));
+  }
+
+  const int32_t max = (1 << 20) - 1;
+  for (int i = max; i > max - 10; i--) {
+    CHECK_INT32V_INLINE(i, 3, U32V_3(i));
+  }
+}
+
+TEST_F(DecoderTest, ReadI32v_FourByte) {
+  CHECK_INT32V_INLINE(0, 4, U32V_4(0));
+  CHECK_INT32V_INLINE(9, 4, U32V_4(9));
+  CHECK_INT32V_INLINE(61, 4, U32V_4(61));
+  CHECK_INT32V_INLINE(63, 4, U32V_4(63));
+
+  CHECK_INT32V_INLINE(-1, 4, U32V_4(-1));
+  CHECK_INT32V_INLINE(-2, 4, U32V_4(-2));
+  CHECK_INT32V_INLINE(-63, 4, U32V_4(-63));
+  CHECK_INT32V_INLINE(-64, 4, U32V_4(-64));
+
+  CHECK_INT32V_INLINE(-267, 4, U32V_4(-267));
+  CHECK_INT32V_INLINE(-1612, 4, U32V_4(-1612));
+  CHECK_INT32V_INLINE(-4667, 4, U32V_4(-4667));
+  CHECK_INT32V_INLINE(-16067, 4, U32V_4(-16067));
+  CHECK_INT32V_INLINE(-264061, 4, U32V_4(-264061));
+  CHECK_INT32V_INLINE(-1264061, 4, U32V_4(-1264061));
+  CHECK_INT32V_INLINE(-6264061, 4, U32V_4(-6264061));
+  CHECK_INT32V_INLINE(-8264061, 4, U32V_4(-8264061));
+
+  CHECK_INT32V_INLINE(277, 4, U32V_4(277));
+  CHECK_INT32V_INLINE(1709, 4, U32V_4(1709));
+  CHECK_INT32V_INLINE(4772, 4, U32V_4(4772));
+  CHECK_INT32V_INLINE(67372, 4, U32V_4(67372));
+  CHECK_INT32V_INLINE(374372, 4, U32V_4(374372));
+  CHECK_INT32V_INLINE(2374372, 4, U32V_4(2374372));
+  CHECK_INT32V_INLINE(7374372, 4, U32V_4(7374372));
+  CHECK_INT32V_INLINE(9374372, 4, U32V_4(9374372));
+
+  const int32_t min = 0 - (1 << 27);
+  for (int i = min; i < min + 10; i++) {
+    CHECK_INT32V_INLINE(i, 4, U32V_4(i));
+  }
+
+  const int32_t max = (1 << 27) - 1;
+  for (int i = max; i > max - 10; i--) {
+    CHECK_INT32V_INLINE(i, 4, U32V_4(i));
+  }
+}
+
+TEST_F(DecoderTest, ReadI32v_FiveByte) {
+  CHECK_INT32V_INLINE(0, 5, U32V_5(0));
+  CHECK_INT32V_INLINE(16, 5, U32V_5(16));
+  CHECK_INT32V_INLINE(94, 5, U32V_5(94));
+  CHECK_INT32V_INLINE(127, 5, U32V_5(127));
+
+  CHECK_INT32V_INLINE(-1, 5, U32V_5(-1));
+  CHECK_INT32V_INLINE(-2, 5, U32V_5(-2));
+  CHECK_INT32V_INLINE(-63, 5, U32V_5(-63));
+  CHECK_INT32V_INLINE(-64, 5, U32V_5(-64));
+
+  CHECK_INT32V_INLINE(-257, 5, U32V_5(-257));
+  CHECK_INT32V_INLINE(-1512, 5, U32V_5(-1512));
+  CHECK_INT32V_INLINE(-4567, 5, U32V_5(-4567));
+  CHECK_INT32V_INLINE(-15067, 5, U32V_5(-15067));
+  CHECK_INT32V_INLINE(-254061, 5, U32V_5(-254061));
+  CHECK_INT32V_INLINE(-1364061, 5, U32V_5(-1364061));
+  CHECK_INT32V_INLINE(-6364061, 5, U32V_5(-6364061));
+  CHECK_INT32V_INLINE(-8364061, 5, U32V_5(-8364061));
+  CHECK_INT32V_INLINE(-28364061, 5, U32V_5(-28364061));
+  CHECK_INT32V_INLINE(-228364061, 5, U32V_5(-228364061));
+
+  CHECK_INT32V_INLINE(227, 5, U32V_5(227));
+  CHECK_INT32V_INLINE(1209, 5, U32V_5(1209));
+  CHECK_INT32V_INLINE(4272, 5, U32V_5(4272));
+  CHECK_INT32V_INLINE(62372, 5, U32V_5(62372));
+  CHECK_INT32V_INLINE(324372, 5, U32V_5(324372));
+  CHECK_INT32V_INLINE(2274372, 5, U32V_5(2274372));
+  CHECK_INT32V_INLINE(7274372, 5, U32V_5(7274372));
+  CHECK_INT32V_INLINE(9274372, 5, U32V_5(9274372));
+  CHECK_INT32V_INLINE(42374372, 5, U32V_5(42374372));
+  CHECK_INT32V_INLINE(429374372, 5, U32V_5(429374372));
+
+  const int32_t min = kMinInt;
+  for (int i = min; i < min + 10; i++) {
+    CHECK_INT32V_INLINE(i, 5, U32V_5(i));
+  }
+
+  const int32_t max = kMaxInt;
+  for (int i = max; i > max - 10; i--) {
+    CHECK_INT32V_INLINE(i, 5, U32V_5(i));
+  }
+}
+
+TEST_F(DecoderTest, ReadU32v_off_end1) {
+  static const byte data[] = {U32V_1(11)};
+  int length = 0;
+  decoder.Reset(data, data);
+  decoder.checked_read_u32v(decoder.start(), 0, &length);
+  EXPECT_EQ(0, length);
+  EXPECT_FALSE(decoder.ok());
+}
+
+TEST_F(DecoderTest, ReadU32v_off_end2) {
+  static const byte data[] = {U32V_2(1111)};
+  for (size_t i = 0; i < sizeof(data); i++) {
+    int length = 0;
+    decoder.Reset(data, data + i);
+    decoder.checked_read_u32v(decoder.start(), 0, &length);
+    EXPECT_EQ(i, length);
+    EXPECT_FALSE(decoder.ok());
+  }
+}
+
+TEST_F(DecoderTest, ReadU32v_off_end3) {
+  static const byte data[] = {U32V_3(111111)};
+  for (size_t i = 0; i < sizeof(data); i++) {
+    int length = 0;
+    decoder.Reset(data, data + i);
+    decoder.checked_read_u32v(decoder.start(), 0, &length);
+    EXPECT_EQ(i, length);
+    EXPECT_FALSE(decoder.ok());
+  }
+}
+
+TEST_F(DecoderTest, ReadU32v_off_end4) {
+  static const byte data[] = {U32V_4(11111111)};
+  for (size_t i = 0; i < sizeof(data); i++) {
+    int length = 0;
+    decoder.Reset(data, data + i);
+    decoder.checked_read_u32v(decoder.start(), 0, &length);
+    EXPECT_EQ(i, length);
+    EXPECT_FALSE(decoder.ok());
+  }
+}
+
+TEST_F(DecoderTest, ReadU32v_off_end5) {
+  static const byte data[] = {U32V_5(111111111)};
+  for (size_t i = 0; i < sizeof(data); i++) {
+    int length = 0;
+    decoder.Reset(data, data + i);
+    decoder.checked_read_u32v(decoder.start(), 0, &length);
+    EXPECT_EQ(i, length);
+    EXPECT_FALSE(decoder.ok());
+  }
+}
+
+TEST_F(DecoderTest, ReadU32v_extra_bits) {
+  byte data[] = {0x80, 0x80, 0x80, 0x80, 0x00};
+  for (int i = 1; i < 16; i++) {
+    data[4] = static_cast<byte>(i << 4);
+    int length = 0;
+    decoder.Reset(data, data + sizeof(data));
+    decoder.checked_read_u32v(decoder.start(), 0, &length);
+    EXPECT_EQ(5, length);
+    EXPECT_FALSE(decoder.ok());
+  }
+}
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8