cloudflare · ketanhwr · Mar 12, 2025 · Mar 11, 2025 · Mar 12, 2025
@@ -30,6 +30,7 @@ PATCHES = [
     "0022-Reset-code_range_-before-pointer-compression-cage.patch",
     "0023-Move-tear-down-in-IsolateGroup-Release-into-destruct.patch",
     "0024-Modify-where-to-look-for-fast_float-and-simdutf.patch",
+    "0025-add-processed_characters-option-to-WriteUtf8V2.patch",
 ]
 
 # V8 and its dependencies

@@ -56,7 +56,7 @@ To update the version of V8 used by workerd, the steps are:
    the command would be:
 
    ```sh
-   git format-patch --full-index -k --no-signature --no-stat HEAD~19
+   git format-patch --full-index -k --no-signature --no-stat --zero-commit HEAD~19
    ```
 
 8. Remove the existing patches from `workerd/patches/v8` and copy over the latest generated patches

@@ -5,7 +5,7 @@ Subject: Allow Windows builds under Bazel
 
 
 diff --git a/BUILD.bazel b/BUILD.bazel
-index 967f7bbfb2810366de89b7a7a90f284efab6c9c6..bfe3365942400fc77f346f2138ac31014f1020aa 100644
+index 967f7bbfb2810366de89b7a7a90f284efab6c9c6..702648004a7c68721c80e7b43cdcd355ceb16710 100644
 --- a/BUILD.bazel
 +++ b/BUILD.bazel
 @@ -3829,6 +3829,8 @@ filegroup(

@@ -8,7 +8,7 @@ speedup for the build: Components like ICU were previously compiled in
 both target and exec configurations as generator tools depend on them.
 
 diff --git a/BUILD.bazel b/BUILD.bazel
-index bfe3365942400fc77f346f2138ac31014f1020aa..96a35feb537ddc9edf864cadba402dfcc40f4ed6 100644
+index 702648004a7c68721c80e7b43cdcd355ceb16710..e65bd03bec247979b2825584f5b59e5ab0c40283 100644
 --- a/BUILD.bazel
 +++ b/BUILD.bazel
 @@ -17,6 +17,7 @@ load(
@@ -19,7 +19,7 @@ index bfe3365942400fc77f346f2138ac31014f1020aa..96a35feb537ddc9edf864cadba402dfc
  )
  load(":bazel/v8-non-pointer-compression.bzl", "v8_binary_non_pointer_compression")
 
-@@ -4219,22 +4220,20 @@ filegroup(
+@@ -4217,22 +4218,20 @@ filegroup(
      ],
  )
 
@@ -48,7 +48,7 @@ index bfe3365942400fc77f346f2138ac31014f1020aa..96a35feb537ddc9edf864cadba402dfc
  )
 
  v8_mksnapshot(
-@@ -4443,7 +4442,6 @@ v8_binary(
+@@ -4441,7 +4440,6 @@ v8_binary(
      srcs = [
          "src/regexp/gen-regexp-special-case.cc",
          "src/regexp/special-case.h",

@@ -7,10 +7,10 @@ Subject: Modify where to look for fp16 dependency. This dependency is normally
 
 
 diff --git a/BUILD.bazel b/BUILD.bazel
-index 96a35feb537ddc9edf864cadba402dfcc40f4ed6..bf957ac52fc0d99ec4c18b325bef455e1c92c4c3 100644
+index e65bd03bec247979b2825584f5b59e5ab0c40283..bfc3ab07e3efddc81965bb8dfbe7ce1f50aa72b2 100644
 --- a/BUILD.bazel
 +++ b/BUILD.bazel
-@@ -3843,16 +3843,22 @@ filegroup(
+@@ -3841,16 +3841,22 @@ filegroup(
      }),
  )
 

@@ -5,7 +5,7 @@ Subject: Enable V8 shared linkage
 
 
 diff --git a/BUILD.bazel b/BUILD.bazel
-index bf957ac52fc0d99ec4c18b325bef455e1c92c4c3..0b95fa690001e06ef39227c66dbd0866d33b2926 100644
+index bfc3ab07e3efddc81965bb8dfbe7ce1f50aa72b2..aa72436fed2ce640b919caefac2ccad700f1c400 100644
 --- a/BUILD.bazel
 +++ b/BUILD.bazel
 @@ -1372,6 +1372,7 @@ filegroup(
@@ -41,15 +41,15 @@ index bf957ac52fc0d99ec4c18b325bef455e1c92c4c3..0b95fa690001e06ef39227c66dbd0866
          "src/builtins/setup-builtins-internal.cc",
          "src/builtins/torque-csa-header-includes.h",
          "src/codegen/turboshaft-builtins-assembler-inl.h",
-@@ -3909,6 +3906,7 @@ filegroup(
+@@ -3907,6 +3904,7 @@ filegroup(
          "src/snapshot/snapshot-empty.cc",
          "src/snapshot/static-roots-gen.cc",
          "src/snapshot/static-roots-gen.h",
 +        "src/execution/isolate.cc",
      ],
  )
 
-@@ -4019,6 +4017,10 @@ filegroup(
+@@ -4017,6 +4015,10 @@ filegroup(
      name = "noicu/snapshot_files",
      srcs = [
          "src/init/setup-isolate-deserialize.cc",
@@ -60,7 +60,7 @@ index bf957ac52fc0d99ec4c18b325bef455e1c92c4c3..0b95fa690001e06ef39227c66dbd0866
      ] + select({
          "@v8//bazel/config:v8_target_arm": [
              "google3/snapshots/arm/noicu/embedded.S",
-@@ -4036,6 +4038,7 @@ filegroup(
+@@ -4034,6 +4036,7 @@ filegroup(
      name = "icu/snapshot_files",
      srcs = [
          "src/init/setup-isolate-deserialize.cc",

@@ -13,10 +13,10 @@ and hwy bindings as a whole are no longer needed; this patch can be dropped.
 Change-Id: I7c52113596247f8f254ac5f882b41da1ba32e3b1
 
 diff --git a/BUILD.bazel b/BUILD.bazel
-index 0b95fa690001e06ef39227c66dbd0866d33b2926..42198db354f84480b3a16ef8df2556bbfb65819a 100644
+index aa72436fed2ce640b919caefac2ccad700f1c400..f19f85b5b94a36b0b00c37b075e6cc7291ee0b34 100644
 --- a/BUILD.bazel
 +++ b/BUILD.bazel
-@@ -4302,6 +4302,10 @@ cc_library(
+@@ -4300,6 +4300,10 @@ cc_library(
          "src/torque/kythe-data.h",
          "src/torque/torque-compiler.h",
      ],

@@ -6,7 +6,7 @@ Subject: Modify where to look for fast_float and simdutf.
 Similar to fp16, these dependencies now needs to be downloaded by bazel.
 
 diff --git a/BUILD.bazel b/BUILD.bazel
-index 42198db354f84480b3a16ef8df2556bbfb65819a..053ad3d3c264e6e098fea9ac3b2a371aeac3b765 100644
+index f19f85b5b94a36b0b00c37b075e6cc7291ee0b34..19d7d942c9dc49b48425285d92d6c93e27371ab9 100644
 --- a/BUILD.bazel
 +++ b/BUILD.bazel
 @@ -2542,8 +2542,6 @@ filegroup(
@@ -18,7 +18,7 @@ index 42198db354f84480b3a16ef8df2556bbfb65819a..053ad3d3c264e6e098fea9ac3b2a371a
          "third_party/siphash/halfsiphash.cc",
          "third_party/siphash/halfsiphash.h",
          "third_party/utf8-decoder/utf8-decoder.h",
-@@ -4327,12 +4325,6 @@ cc_library(
+@@ -4325,12 +4323,6 @@ cc_library(
      ],
  )
 
@@ -31,7 +31,7 @@ index 42198db354f84480b3a16ef8df2556bbfb65819a..053ad3d3c264e6e098fea9ac3b2a371a
  v8_library(
      name = "v8_libshared",
      srcs = [
-@@ -4361,9 +4353,9 @@ v8_library(
+@@ -4359,9 +4351,9 @@ v8_library(
          ":noicu/generated_torque_definitions",
      ],
      deps = [

@@ -0,0 +1,189 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Yagiz Nizipli <yagiz@nizipli.com>
+Date: Tue, 18 Feb 2025 11:21:51 -0500
+Subject: add processed_characters option to WriteUtf8V2
+
+Bug: https://issues.chromium.org/issues/397377176
+
+Change-Id: I22086a675eb5565bef254a94ac1b6827a1c61a51
+Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6276706
+Reviewed-by: Erik Corry <erikcorry@chromium.org>
+Auto-Submit: Yagiz Nizipli <yagiz@nizipli.com>
+Commit-Queue: Leszek Swirski <leszeks@chromium.org>
+Reviewed-by: Leszek Swirski <leszeks@chromium.org>
+Cr-Commit-Position: refs/heads/main@{#98780}
+
+diff --git a/include/v8-primitive.h b/include/v8-primitive.h
+index 01773bcaff9b921e77ae70ef09d8a30c1637d533..b608535abae0ed2d5ee74a327203a4bffb9847fd 100644
+--- a/include/v8-primitive.h
++++ b/include/v8-primitive.h
+@@ -257,11 +257,14 @@ class V8_EXPORT String : public Name {
+    * \param buffer The buffer into which the string will be written.
+    * \param capacity The number of bytes available in the output buffer.
+    * \param flags Various flags that influence the behavior of this operation.
++   * \param processed_characters_return The number of processed characters from
++   * the buffer.
+    * \return The number of bytes copied to the buffer including the null
+    * terminator (if written).
+    */
+   size_t WriteUtf8V2(Isolate* isolate, char* buffer, size_t capacity,
+-                     int flags = WriteFlags::kNone) const;
++                     int flags = WriteFlags::kNone,
++                     size_t* processed_characters_return = nullptr) const;
+
+   /**
+    * A zero length string.
+diff --git a/src/api/api.cc b/src/api/api.cc
+index fccbd853f957617c79d97dbdd69fec7c39f65af5..43540a968a5b7e94c3e883d1bf8b5f51072bae05 100644
+--- a/src/api/api.cc
++++ b/src/api/api.cc
+@@ -6163,7 +6163,8 @@ void String::WriteOneByteV2(Isolate* v8_isolate, uint32_t offset,
+ }
+
+ size_t String::WriteUtf8V2(Isolate* v8_isolate, char* buffer, size_t capacity,
+-                           int flags) const {
++                           int flags,
++                           size_t* processed_characters_return) const {
+   auto str = Utils::OpenDirectHandle(this);
+   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+   API_RCS_SCOPE(i_isolate, String, WriteUtf8);
+@@ -6175,7 +6176,8 @@ size_t String::WriteUtf8V2(Isolate* v8_isolate, char* buffer, size_t capacity,
+   if (flags & String::WriteFlags::kReplaceInvalidUtf8) {
+     i_flags |= i::String::Utf8EncodingFlag::kReplaceInvalid;
+   }
+-  return i::String::WriteUtf8(i_isolate, str, buffer, capacity, i_flags);
++  return i::String::WriteUtf8(i_isolate, str, buffer, capacity, i_flags,
++                              processed_characters_return);
+ }
+
+ namespace {
+diff --git a/src/objects/string.cc b/src/objects/string.cc
+index e6ad2e286bdb05273f0152c214f34f332d67854c..a6013dd168a31e336e79ce5019b36482b6096211 100644
+--- a/src/objects/string.cc
++++ b/src/objects/string.cc
+@@ -1111,8 +1111,8 @@ void String::WriteToFlat2(SinkCharT* dst, Tagged<ConsString> src,
+
+ // static
+ size_t String::WriteUtf8(Isolate* isolate, DirectHandle<String> string,
+-                         char* buffer, size_t capacity,
+-                         Utf8EncodingFlags flags) {
++                         char* buffer, size_t capacity, Utf8EncodingFlags flags,
++                         size_t* processed_characters_return) {
+   DCHECK_IMPLIES(flags & Utf8EncodingFlag::kNullTerminate, capacity > 0);
+   DCHECK_IMPLIES(capacity > 0, buffer != nullptr);
+
+@@ -1121,19 +1121,22 @@ size_t String::WriteUtf8(Isolate* isolate, DirectHandle<String> string,
+   DisallowGarbageCollection no_gc;
+   FlatContent content = string->GetFlatContent(no_gc);
+   DCHECK(content.IsFlat());
+-  if (content.IsOneByte()) {
+-    return unibrow::Utf8::Encode<uint8_t>(
+-               content.ToOneByteVector(), buffer, capacity,
+-               flags & Utf8EncodingFlag::kNullTerminate,
+-               flags & Utf8EncodingFlag::kReplaceInvalid)
+-        .bytes_written;
+-  } else {
+-    return unibrow::Utf8::Encode<uint16_t>(
+-               content.ToUC16Vector(), buffer, capacity,
+-               flags & Utf8EncodingFlag::kNullTerminate,
+-               flags & Utf8EncodingFlag::kReplaceInvalid)
+-        .bytes_written;
++
++  auto encoding_result = content.IsOneByte()
++                             ? unibrow::Utf8::Encode<uint8_t>(
++                                   content.ToOneByteVector(), buffer, capacity,
++                                   flags & Utf8EncodingFlag::kNullTerminate,
++                                   flags & Utf8EncodingFlag::kReplaceInvalid)
++                             : unibrow::Utf8::Encode<uint16_t>(
++                                   content.ToUC16Vector(), buffer, capacity,
++                                   flags & Utf8EncodingFlag::kNullTerminate,
++                                   flags & Utf8EncodingFlag::kReplaceInvalid);
++
++  if (processed_characters_return != nullptr) {
++    *processed_characters_return = encoding_result.characters_processed;
+   }
++
++  return encoding_result.bytes_written;
+ }
+
+ template <typename SourceChar>
+diff --git a/src/objects/string.h b/src/objects/string.h
+index d456749e52cbbab17b95334bcc6fee18a597fe58..238310eb3d89a2e9206ff6f58c4fcfacd00bba33 100644
+--- a/src/objects/string.h
++++ b/src/objects/string.h
+@@ -553,7 +553,8 @@ V8_OBJECT class String : public Name {
+   using Utf8EncodingFlags = base::Flags<Utf8EncodingFlag>;
+   static size_t WriteUtf8(Isolate* isolate, DirectHandle<String> string,
+                           char* buffer, size_t capacity,
+-                          Utf8EncodingFlags flags);
++                          Utf8EncodingFlags flags,
++                          size_t* processed_characters_return = nullptr);
+
+   // Returns true if this string has no unpaired surrogates and false otherwise.
+   static inline bool IsWellFormedUnicode(Isolate* isolate,
+diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
+index 3e7f2aa117f64c9ef00bcd9f3492d4e39e5945f0..434a6f56ce6389f9eec463386e19cb61c08e6206 100644
+--- a/test/cctest/test-api.cc
++++ b/test/cctest/test-api.cc
+@@ -8607,6 +8607,7 @@ THREADED_TEST(StringWrite) {
+   char utf8buf[0xD800 * 3];
+   uint16_t wbuf[100];
+   size_t len;
++  size_t processed_characters;
+
+   memset(utf8buf, 0x1, 1000);
+   len = v8::String::Empty(isolate)->WriteUtf8V2(
+@@ -8621,8 +8622,10 @@ THREADED_TEST(StringWrite) {
+   CHECK_EQ(0, strcmp(utf8buf, "abc\xC3\xB0\xE2\x98\x83"));
+
+   memset(utf8buf, 0x1, 1000);
+-  len = str2->WriteUtf8V2(isolate, utf8buf, 8);
++  len = str2->WriteUtf8V2(isolate, utf8buf, 8, String::WriteFlags::kNone,
++                          &processed_characters);
+   CHECK_EQ(8, len);
++  CHECK_EQ(5, processed_characters);
+   CHECK_EQ(0, strncmp(utf8buf, "abc\xC3\xB0\xE2\x98\x83\x01", 9));
+
+   memset(utf8buf, 0x1, 1000);
+@@ -8828,8 +8831,10 @@ THREADED_TEST(StringWrite) {
+
+   memset(utf8buf, 0x1, sizeof(utf8buf));
+   utf8buf[5] = 'X';
+-  len = str->WriteUtf8V2(isolate, utf8buf, sizeof(utf8buf));
++  len = str->WriteUtf8V2(isolate, utf8buf, sizeof(utf8buf),
++                         String::WriteFlags::kNone, &processed_characters);
+   CHECK_EQ(5, len);
++  CHECK_EQ(5, processed_characters);
+   CHECK_EQ('X', utf8buf[5]);  // Test that the sixth character is untouched.
+   utf8buf[5] = '\0';
+   CHECK_EQ(0, strcmp(utf8buf, "abcde"));
+@@ -8846,6 +8851,29 @@ THREADED_TEST(StringWrite) {
+   str->WriteV2(isolate, 0, 0, nullptr);
+   len = str->WriteUtf8V2(isolate, nullptr, 0);
+   CHECK_EQ(0, len);
++
++  std::tuple<const char*, size_t, size_t> cases[] = {
++      {"\xC3\xA9", 0, 0},          // é (2-byte) but buffer is 0
++      {"\xC3\xA9", 1, 0},          // é (2-byte) but buffer is 1
++      {"\xE2\x82\xAC", 0, 0},      // € (3-byte) but buffer is 0
++      {"\xE2\x82\xAC", 1, 0},      // € (3-byte) but buffer is 1
++      {"\xE2\x82\xAC", 2, 0},      // € (3-byte) but buffer is 2
++      {"\xF0\x9F\x98\x81", 0, 0},  // 😁 (4-byte) but buffer is 0
++      {"\xF0\x9F\x98\x81", 1, 0},  // 😁 (4-byte) but buffer is 1
++      {"\xF0\x9F\x98\x81", 2, 0},  // 😁 (4-byte) but buffer is 2
++  };
++
++  for (const auto& test_case : cases) {
++    auto test_str =
++        String::NewFromUtf8(isolate, std::get<0>(test_case)).ToLocalChecked();
++    auto test_buffer_capacity = std::get<1>(test_case);
++    char test_buffer[4];
++    len =
++        test_str->WriteUtf8V2(isolate, test_buffer, test_buffer_capacity,
++                              String::WriteFlags::kNone, &processed_characters);
++    CHECK_EQ(std::get<2>(test_case), len);
++    CHECK_EQ(0, processed_characters);
++  }
+ }
+
+ static void Utf16Helper(LocalContext& context, const char* name,