[wasm] Update {i32,i64}.const to use signed leb128

test/unittests/wasm/decoder-unittest.cc

 // 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 {
@@ skipping 410 matching lines @@
   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());
   }
 }
 
+TEST_F(DecoderTest, ReadI32v_extra_bits_negative) {
+  // OK for negative signed values to have extra ones.
+  int length = 0;
+  byte data[] = {0xff, 0xff, 0xff, 0xff, 0x7f};
+  decoder.Reset(data, data + sizeof(data));
+  decoder.checked_read_i32v(decoder.start(), 0, &length);
+  EXPECT_EQ(5, length);
+  EXPECT_TRUE(decoder.ok());
+}
+
+TEST_F(DecoderTest, ReadI32v_extra_bits_positive) {
+  // Not OK for positive signed values to have extra ones.
+  int length = 0;
+  byte data[] = {0x80, 0x80, 0x80, 0x80, 0x77};
+  decoder.Reset(data, data + sizeof(data));
+  decoder.checked_read_i32v(decoder.start(), 0, &length);
+  EXPECT_EQ(5, length);
+  EXPECT_FALSE(decoder.ok());
+}
+
 TEST_F(DecoderTest, ReadU32v_Bits) {
   // A more exhaustive test.
   const int kMaxSize = 5;
   const uint32_t kVals[] = {
       0xaabbccdd, 0x11223344, 0x33445566, 0xffeeddcc, 0xF0F0F0F0, 0x0F0F0F0F,
       0xEEEEEEEE, 0xAAAAAAAA, 0x12345678, 0x9abcdef0, 0x80309488, 0x729ed997,
       0xc4a0cf81, 0x16c6eb85, 0x4206db8e, 0xf3b089d5, 0xaa2e223e, 0xf99e29c8,
       0x4a4357d8, 0x1890b1c1, 0x8d80a085, 0xacb6ae4c, 0x1b827e10, 0xeb5c7bd9,
       0xbb1bc146, 0xdf57a33l};
   byte data[kMaxSize];
@@ skipping 139 matching lines @@
   byte data[kMaxSize];
 
   // foreach value in above array
   for (size_t v = 0; v < arraysize(kVals); v++) {
     // foreach length 1...64
     for (int i = 1; i <= 64; i++) {
       const int64_t val = bit_cast<int64_t>(kVals[v] << (64 - i)) >> (64 - i);
 
       int length = 1 + i / 7;
       for (int j = 0; j < kMaxSize; j++) {
-        const uint64_t uval = bit_cast<uint64_t>(val);
-        data[j] = static_cast<byte>((uval >> (7 * j)) & MASK_7);
+        data[j] = static_cast<byte>((val >> (7 * j)) & MASK_7);
       }
       for (int j = 0; j < length - 1; j++) {
         data[j] |= 0x80;
       }
 
       // foreach buffer size 0...10
       for (int limit = 0; limit <= kMaxSize; limit++) {
         decoder.Reset(data, data + limit);
         int rlen;
         int64_t result = decoder.checked_read_i64v(data, 0, &rlen);
@@ skipping 14 matching lines @@
   for (int i = 1; i < 128; i++) {
     data[9] = static_cast<byte>(i << 1);
     int length = 0;
     decoder.Reset(data, data + sizeof(data));
     decoder.checked_read_u64v(decoder.start(), 0, &length);
     EXPECT_EQ(10, length);
     EXPECT_FALSE(decoder.ok());
   }
 }
 
+TEST_F(DecoderTest, ReadI64v_extra_bits_negative) {
+  // OK for negative signed values to have extra ones.
+  int length = 0;
+  byte data[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f};
+  decoder.Reset(data, data + sizeof(data));
+  decoder.checked_read_i64v(decoder.start(), 0, &length);
+  EXPECT_EQ(10, length);
+  EXPECT_TRUE(decoder.ok());
+}
+
+TEST_F(DecoderTest, ReadI64v_extra_bits_positive) {
+  // Not OK for positive signed values to have extra ones.
+  int length = 0;
+  byte data[] = {0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x77};
+  decoder.Reset(data, data + sizeof(data));
+  decoder.checked_read_i64v(decoder.start(), 0, &length);
+  EXPECT_EQ(10, length);
+  EXPECT_FALSE(decoder.ok());
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8