1 files changed, 166 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testWasmLEB128.cpp b/js/src/jsapi-tests/testWasmLEB128.cpp
new file mode 100644
index 000000000..d39658e12
--- /dev/null
+++ b/js/src/jsapi-tests/testWasmLEB128.cpp
@@ -0,0 +1,166 @@
+/* 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/WasmBinaryFormat.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)