From: Lucas C.S. Subject: [PATCH] blink/platform/fonts: keep the OpenType format check on cxx, not Crubit Revert of upstream 493e6c3911e3 ("Migrate OpenType format check bindings to Crubit", 2026-08-13), which landed in M153. That commit moved blink's FontFormatCheck from a `cxx` bridge to a Crubit `cpp_api_from_rust` binding and made `//third_party/blink/renderer/platform` depend on `//build/rust/crubit` unconditionally. Crubit's C++ support library is not in the Chromium tree: `//build_overrides/crubit.gni` hardcodes `crubit_src_dir` to `//third_party/rust-toolchain/lib/third_party/crubit`, which exists only inside Google's bundled Rust toolchain and which the release tarball does not ship. A build against a system Rust sysroot therefore dies in `gn gen`: ERROR at //build/rust/crubit/BUILD.gn:11:5: Unable to load ".../third_party/rust-toolchain/lib/third_party/crubit/support/BUILD.gn". "$crubit_src_dir/support:support_cpp", Unlike components/cbor (see chromium-152-cbor-crubit-optional.patch) there is no C++ fallback to gate on `enable_cpp_api_from_rust`: font_format_check.cc calls the generated `font_format::*` functions directly, and with a system sysroot `//build/rust/gni_impl/rust_target.gni` never even defines the `font_format_bindings` target. The only working path without the bundled toolchain is the one M152 shipped, so this restores it wholesale: the `cxx` bridge in format_check.rs, `rust::Box` in the header, the `rust_static_library("font_format_check")` target in platform/BUILD.gn, and drops the new fonts/BUILD.gn. `cxx_bindings` is still a supported `rust_static_library` attribute in M153 (rustfft_ffi in the same file uses it), and the Rust logic itself is unchanged -- the commit only flipped `fn` -> `pub fn` and `Box` -> `T`. Applied only with USE=-bundled-toolchain; with the bundled toolchain the upstream Crubit path works as-is. Drop this patch once upstream gates the Crubit dependency on `enable_cpp_api_from_rust` or ships Crubit's support library outside the toolchain. diff -ruN a/third_party/blink/renderer/platform/BUILD.gn b/third_party/blink/renderer/platform/BUILD.gn --- a/third_party/blink/renderer/platform/BUILD.gn +++ b/third_party/blink/renderer/platform/BUILD.gn @@ -186,6 +186,18 @@ ] } +rust_static_library("font_format_check") { + allow_unsafe = true # Needed for FFI that underpins the `cxx` crate. + crate_root = "fonts/opentype/format_check.rs" + sources = [ crate_root ] + cxx_bindings = [ crate_root ] + deps = [ + "//third_party/rust/font_types/v0_12:lib", + "//third_party/rust/read_fonts/v0_41:lib", + "//third_party/rust/skrifa/v0_44:lib", + ] +} + rust_static_library("rustfft_ffi") { allow_unsafe = true # Needed for FFI that underpins the `cxx` crate. crate_root = "audio/rustfft_ffi.rs" @@ -1794,7 +1806,6 @@ ":allow_discouraged_type", ":blink_platform_public_deps", ":platform_export", - "//build/rust/crubit", "//gpu/command_buffer/client:raster_interface", "//media/capture:capture_lib", "//mojo/public/cpp/base", @@ -1821,8 +1832,8 @@ "//ui/native_theme/features", ] deps = [ + ":font_format_check", ":rustfft_ffi", - "fonts:font_format_bindings", "//base:base_static", "//base/allocator:buildflags", "//build:chromecast_buildflags", diff -ruN a/third_party/blink/renderer/platform/fonts/BUILD.gn b/third_party/blink/renderer/platform/fonts/BUILD.gn --- a/third_party/blink/renderer/platform/fonts/BUILD.gn +++ /dev/null @@ -1,19 +0,0 @@ -# Copyright 2026 The Chromium Authors -# Use of this source code is governed by a BSD-style license that can be -# found in the LICENSE file. - -import("//build/rust/rust_static_library.gni") - -rust_static_library("font_format") { - crate_root = "opentype/format_check.rs" - sources = [ crate_root ] - cpp_api_from_rust = { - target_name = "font_format_bindings" - cpp_namespace = "font_format" - } - deps = [ - "//third_party/rust/font_types/v0_12:lib", - "//third_party/rust/read_fonts/v0_41:lib", - "//third_party/rust/skrifa/v0_44:lib", - ] -} diff -ruN a/third_party/blink/renderer/platform/fonts/opentype/font_format_check.cc b/third_party/blink/renderer/platform/fonts/opentype/font_format_check.cc --- a/third_party/blink/renderer/platform/fonts/opentype/font_format_check.cc +++ b/third_party/blink/renderer/platform/fonts/opentype/font_format_check.cc @@ -7,6 +7,7 @@ #include "base/containers/span.h" #include "base/containers/span_rust.h" #include "base/numerics/byte_conversions.h" +#include "third_party/blink/renderer/platform/fonts/opentype/format_check.rs.h" #include "third_party/blink/renderer/platform/runtime_enabled_features.h" #include "third_party/blink/renderer/platform/wtf/vector.h" #include "third_party/skia/include/core/SkTypeface.h" @@ -14,37 +15,35 @@ namespace blink { FontFormatCheck::FontFormatCheck(sk_sp sk_data) - : format_info_(font_format::get_font_format_info( + : format_info_(font_format_check::get_font_format_info( base::SpanToRustSlice(sk_data->byteSpan()))) {} -FontFormatCheck::~FontFormatCheck() = default; - bool FontFormatCheck::IsVariableFont() const { - return font_format::is_variable(format_info_); + return font_format_check::is_variable(*format_info_); } bool FontFormatCheck::IsCbdtCblcColorFont() const { - return font_format::is_cbdt_cblc(format_info_); + return font_format_check::is_cbdt_cblc(*format_info_); } bool FontFormatCheck::IsEbdtEblcMonochromeFont() const { - return font_format::is_ebdt_eblc(format_info_); + return font_format_check::is_ebdt_eblc(*format_info_); } bool FontFormatCheck::IsColrCpalColorFontV0() const { - return font_format::is_colrv0(format_info_); + return font_format_check::is_colrv0(*format_info_); } bool FontFormatCheck::IsColrCpalColorFontV1() const { - return font_format::is_colrv1(format_info_); + return font_format_check::is_colrv1(*format_info_); } bool FontFormatCheck::IsSbixColorFont() const { - return font_format::is_sbix(format_info_); + return font_format_check::is_sbix(*format_info_); } bool FontFormatCheck::IsCff2OutlineFont() const { - return font_format::is_cff2(format_info_); + return font_format_check::is_cff2(*format_info_); } bool FontFormatCheck::IsVariableColrV0Font() const { @@ -58,7 +57,7 @@ bool FontFormatCheck::IsAvar2Font() const { return RuntimeEnabledFeatures::FontFormatAvar2Enabled() && - font_format::is_avar2(format_info_); + font_format_check::is_avar2(*format_info_); } FontFormatCheck::VariableFontSubType FontFormatCheck::ProbeVariableFont( diff -ruN a/third_party/blink/renderer/platform/fonts/opentype/font_format_check.h b/third_party/blink/renderer/platform/fonts/opentype/font_format_check.h --- a/third_party/blink/renderer/platform/fonts/opentype/font_format_check.h +++ b/third_party/blink/renderer/platform/fonts/opentype/font_format_check.h @@ -5,7 +5,7 @@ #ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_OPENTYPE_FONT_FORMAT_CHECK_H_ #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_OPENTYPE_FONT_FORMAT_CHECK_H_ -#include "third_party/blink/renderer/platform/fonts/font_format.h" +#include "third_party/blink/renderer/platform/fonts/opentype/format_check.rs.h" #include "third_party/blink/renderer/platform/platform_export.h" #include "third_party/blink/renderer/platform/wtf/allocator/allocator.h" #include "third_party/skia/include/core/SkData.h" @@ -19,7 +19,7 @@ public: explicit FontFormatCheck(sk_sp); - virtual ~FontFormatCheck(); + virtual ~FontFormatCheck() = default; virtual bool IsVariableFont() const; virtual bool IsCbdtCblcColorFont() const; virtual bool IsEbdtEblcMonochromeFont() const; @@ -46,7 +46,7 @@ enum class COLRVersion { kCOLRV0, kCOLRV1, kNoCOLR }; private: - font_format::FontFormatInfo format_info_; + rust::Box format_info_; }; } // namespace blink diff -ruN a/third_party/blink/renderer/platform/fonts/opentype/format_check.rs b/third_party/blink/renderer/platform/fonts/opentype/format_check.rs --- a/third_party/blink/renderer/platform/fonts/opentype/format_check.rs +++ b/third_party/blink/renderer/platform/fonts/opentype/format_check.rs @@ -23,7 +23,7 @@ format_flags: Option, } -pub fn get_font_format_info(font_bytes: &[u8]) -> FontFormatInfo { +pub fn get_font_format_info(font_bytes: &[u8]) -> Box { let file_ref = make_font_ref_internal(font_bytes, 0); match file_ref { @@ -32,11 +32,11 @@ font.table_directory().table_records().iter().map(|e| e.tag()).collect(); let color_version = get_colr_version(&font); let avar_version = get_avar_version(&font); - FontFormatInfo { + Box::new(FontFormatInfo { format_flags: Some(FontFormatFlags { table_tags, color_version, avar_version }), - } + }) } - _ => FontFormatInfo::default(), + _ => Box::new(FontFormatInfo::default()), } } @@ -44,10 +44,10 @@ Some(font_ref.colr().ok()?.version()) } -pub fn is_colrv1(format_info: &FontFormatInfo) -> bool { +fn is_colrv1(format_info: &FontFormatInfo) -> bool { matches!(&format_info.format_flags, Some(FontFormatFlags { color_version: Some(1), .. }),) } -pub fn is_colrv0(format_info: &FontFormatInfo) -> bool { +fn is_colrv0(format_info: &FontFormatInfo) -> bool { matches!(&format_info.format_flags, Some(FontFormatFlags { color_version: Some(0), .. }),) } @@ -56,7 +56,7 @@ Some((version.major, version.minor)) } -pub fn is_avar2(format_info: &FontFormatInfo) -> bool { +fn is_avar2(format_info: &FontFormatInfo) -> bool { matches!(&format_info.format_flags, Some(FontFormatFlags { avar_version: Some((2, _)), .. }),) } @@ -69,22 +69,39 @@ } } -pub fn is_variable(format_info: &FontFormatInfo) -> bool { +fn is_variable(format_info: &FontFormatInfo) -> bool { has_tags(format_info, &[Tag::new(b"fvar")]) } -pub fn is_sbix(format_info: &FontFormatInfo) -> bool { +fn is_sbix(format_info: &FontFormatInfo) -> bool { has_tags(format_info, &[Tag::new(b"sbix")]) } -pub fn is_cbdt_cblc(format_info: &FontFormatInfo) -> bool { +fn is_cbdt_cblc(format_info: &FontFormatInfo) -> bool { has_tags(format_info, &[Tag::new(b"CBDT"), Tag::new(b"CBLC")]) } -pub fn is_ebdt_eblc(format_info: &FontFormatInfo) -> bool { +fn is_ebdt_eblc(format_info: &FontFormatInfo) -> bool { has_tags(format_info, &[Tag::new(b"EBDT"), Tag::new(b"EBLC")]) } -pub fn is_cff2(format_info: &FontFormatInfo) -> bool { +fn is_cff2(format_info: &FontFormatInfo) -> bool { has_tags(format_info, &[Tag::new(b"CFF2")]) } + +#[cxx::bridge(namespace = "font_format_check")] +pub mod ffi { + extern "Rust" { + type FontFormatInfo; + + fn get_font_format_info(font_bytes: &[u8]) -> Box; + fn is_colrv1(format_info: &FontFormatInfo) -> bool; + fn is_colrv0(format_info: &FontFormatInfo) -> bool; + fn is_cbdt_cblc(format_info: &FontFormatInfo) -> bool; + fn is_ebdt_eblc(format_info: &FontFormatInfo) -> bool; + fn is_variable(format_info: &FontFormatInfo) -> bool; + fn is_sbix(format_info: &FontFormatInfo) -> bool; + fn is_cff2(format_info: &FontFormatInfo) -> bool; + fn is_avar2(format_info: &FontFormatInfo) -> bool; + } +}