1 files changed, 173 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testWasmLEB128.cpp b/js/src/jsapi-tests/testWasmLEB128.cpp
new file mode 100644
index 0000000000..58ded9ab26
--- /dev/null
+++ b/js/src/jsapi-tests/testWasmLEB128.cpp
@@ -0,0 +1,173 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdlib.h>
+
+#include "jsapi-tests/tests.h"
+
+#include "wasm/WasmValidate.h"
+
+static bool WriteValidBytes(js::wasm::Encoder& encoder, bool* passed) {
+  *passed = false;
+  if (!encoder.empty()) {
+    return true;
+  }
+
+  // These remain the same under LEB128 unsigned encoding
+  if (!encoder.writeVarU32(0x0) || !encoder.writeVarU32(0x1) ||
+      !encoder.writeVarU32(0x42)) {
+    return false;
+  }
+
+  // 0x01 0x80
+  if (!encoder.writeVarU32(0x80)) {
+    return false;
+  }
+
+  // 0x03 0x80
+  if (!encoder.writeVarU32(0x180)) {
+    return false;
+  }
+
+  if (encoder.empty()) {
+    return true;
+  }
+  if (encoder.currentOffset() != 7) {
+    return true;
+  }
+  *passed = true;
+  return true;
+}
+
+BEGIN_TEST(testWasmLEB128_encoding) {
+  using namespace js;
+  using namespace wasm;
+
+  Bytes bytes;
+  Encoder encoder(bytes);
+
+  bool passed;
+  if (!WriteValidBytes(encoder, &passed)) {
+    return false;
+  }
+  CHECK(passed);
+
+  size_t i = 0;
+  CHECK(bytes[i++] == 0x0);
+  CHECK(bytes[i++] == 0x1);
+  CHECK(bytes[i++] == 0x42);
+
+  CHECK(bytes[i++] == 0x80);
+  CHECK(bytes[i++] == 0x01);
+
+  CHECK(bytes[i++] == 0x80);
+  CHECK(bytes[i++] == 0x03);
+
+  if (i + 1 < bytes.length()) {
+    CHECK(bytes[i++] == 0x00);
+  }
+  return true;
+}
+END_TEST(testWasmLEB128_encoding)
+
+BEGIN_TEST(testWasmLEB128_valid_decoding) {
+  using namespace js;
+  using namespace wasm;
+
+  Bytes bytes;
+  if (!bytes.append(0x0) || !bytes.append(0x1) || !bytes.append(0x42)) {
+    return false;
+  }
+
+  if (!bytes.append(0x80) || !bytes.append(0x01)) {
+    return false;
+  }
+
+  if (!bytes.append(0x80) || !bytes.append(0x03)) {
+    return false;
+  }
+
+  {
+    // Fallible decoding
+    Decoder decoder(bytes);
+    uint32_t value;
+
+    CHECK(decoder.readVarU32(&value) && value == 0x0);
+    CHECK(decoder.readVarU32(&value) && value == 0x1);
+    CHECK(decoder.readVarU32(&value) && value == 0x42);
+    CHECK(decoder.readVarU32(&value) && value == 0x80);
+    CHECK(decoder.readVarU32(&value) && value == 0x180);
+
+    CHECK(decoder.done());
+  }
+
+  {
+    // Infallible decoding
+    Decoder decoder(bytes);
+    uint32_t value;
+
+    value = decoder.uncheckedReadVarU32();
+    CHECK(value == 0x0);
+    value = decoder.uncheckedReadVarU32();
+    CHECK(value == 0x1);
+    value = decoder.uncheckedReadVarU32();
+    CHECK(value == 0x42);
+    value = decoder.uncheckedReadVarU32();
+    CHECK(value == 0x80);
+    value = decoder.uncheckedReadVarU32();
+    CHECK(value == 0x180);
+
+    CHECK(decoder.done());
+  }
+  return true;
+}
+END_TEST(testWasmLEB128_valid_decoding)
+
+BEGIN_TEST(testWasmLEB128_invalid_decoding) {
+  using namespace js;
+  using namespace wasm;
+
+  Bytes bytes;
+  // Fill bits as per 28 encoded bits
+  if (!bytes.append(0x80) || !bytes.append(0x80) || !bytes.append(0x80) ||
+      !bytes.append(0x80)) {
+    return false;
+  }
+
+  // Test last valid values
+  if (!bytes.append(0x00)) {
+    return false;
+  }
+
+  for (uint8_t i = 0; i < 0x0F; i++) {
+    bytes[4] = i;
+
+    {
+      Decoder decoder(bytes);
+      uint32_t value;
+      CHECK(decoder.readVarU32(&value));
+      CHECK(value == uint32_t(i << 28));
+      CHECK(decoder.done());
+    }
+
+    {
+      Decoder decoder(bytes);
+      uint32_t value = decoder.uncheckedReadVarU32();
+      CHECK(value == uint32_t(i << 28));
+      CHECK(decoder.done());
+    }
+  }
+
+  // Test all invalid values of the same size
+  for (uint8_t i = 0x10; i < 0xF0; i++) {
+    bytes[4] = i;
+
+    Decoder decoder(bytes);
+    uint32_t value;
+    CHECK(!decoder.readVarU32(&value));
+  }
+
+  return true;
+}
+END_TEST(testWasmLEB128_invalid_decoding)