Script to switch Chromium between vendored and local jxl-rs checkout (symlinks, bisect, override)

use-local-jxl-rs.sh

#!/bin/bash
# Switch Chromium to use local jxl-rs checkout for development
# Usage: ./use-local-jxl-rs.sh [setup|restore|status|clean|bisect|override]

set -e

CHROMIUM_SRC="/home/chrome/chromium_2/src"
CHROMIUM_VENDOR="$CHROMIUM_SRC/third_party/rust/chromium_crates_io/vendor"
LOCAL_JXL="$HOME/jxl-rs_1"
BUILD_GN="$CHROMIUM_SRC/third_party/rust/jxl/v0_3/BUILD.gn"

CRATES=(
    "jxl-v0_3:jxl"
    "jxl_macros-v0_3:jxl_macros"
    "jxl_simd-v0_3:jxl_simd"
    "jxl_transforms-v0_3:jxl_transforms"
)

clean_build_cache() {
    echo "Cleaning jxl build artifacts..."
    rm -rf "$CHROMIUM_SRC/out/Default/obj/third_party/rust/jxl"* 2>/dev/null || true
    rm -rf "$CHROMIUM_SRC/out/Default/clang_x64_for_rust_host_build_tools/libjxl"* 2>/dev/null || true
    echo "  Build cache cleaned."
}

regen_ninja() {
    echo "Regenerating ninja files..."
    cd "$CHROMIUM_SRC" && gn gen out/Default
    echo "  Ninja files regenerated."
}

fix_build_gn() {
    echo "Syncing BUILD.gn with current jxl-rs checkout..."

    # Handle premultiply_alpha.rs - added in d04806e
    if [ -f "$LOCAL_JXL/jxl/src/render/stages/premultiply_alpha.rs" ]; then
        if ! grep -q "premultiply_alpha.rs" "$BUILD_GN" 2>/dev/null; then
            echo "  Adding premultiply_alpha.rs to BUILD.gn..."
            sed -i '/stages\/patches\.rs/a\    "//third_party/rust/chromium_crates_io/vendor/jxl-v0_3/src/render/stages/premultiply_alpha.rs",' "$BUILD_GN"
        fi
    else
        if grep -q "premultiply_alpha.rs" "$BUILD_GN" 2>/dev/null; then
            echo "  Removing premultiply_alpha.rs from BUILD.gn..."
            sed -i '/premultiply_alpha\.rs/d' "$BUILD_GN"
        fi
    fi

    # Handle x86_64.rs - deleted in fa0211d
    if [ -f "$LOCAL_JXL/jxl/src/render/low_memory_pipeline/save/x86_64.rs" ]; then
        if ! grep -q "save/x86_64.rs" "$BUILD_GN" 2>/dev/null; then
            echo "  Adding save/x86_64.rs to BUILD.gn..."
            sed -i '/save\/mod\.rs/a\    "//third_party/rust/chromium_crates_io/vendor/jxl-v0_3/src/render/low_memory_pipeline/save/x86_64.rs",' "$BUILD_GN"
        fi
    else
        if grep -q "save/x86_64.rs" "$BUILD_GN" 2>/dev/null; then
            echo "  Removing save/x86_64.rs from BUILD.gn..."
            sed -i '/save\/x86_64\.rs/d' "$BUILD_GN"
        fi
    fi

    # Handle atomic_refcell - added in eaf6923
    if [ -f "$LOCAL_JXL/jxl/src/util/atomic_refcell/mod.rs" ]; then
        if ! grep -q "atomic_refcell" "$BUILD_GN" 2>/dev/null; then
            echo "  Adding atomic_refcell to BUILD.gn..."
            sed -i '/util\/vec_helpers\.rs/a\    "//third_party/rust/chromium_crates_io/vendor/jxl-v0_3/src/util/atomic_refcell/mod.rs",\n    "//third_party/rust/chromium_crates_io/vendor/jxl-v0_3/src/util/atomic_refcell/internal.rs",' "$BUILD_GN"
        fi
    else
        if grep -q "atomic_refcell" "$BUILD_GN" 2>/dev/null; then
            echo "  Removing atomic_refcell from BUILD.gn..."
            sed -i '/atomic_refcell/d' "$BUILD_GN"
        fi
    fi

    # Handle smallvec.rs - added in 99e245a
    if [ -f "$LOCAL_JXL/jxl/src/util/smallvec.rs" ]; then
        if ! grep -q "util/smallvec.rs" "$BUILD_GN" 2>/dev/null; then
            echo "  Adding smallvec.rs to BUILD.gn..."
            sed -i '/util\/vec_helpers\.rs/a\    "//third_party/rust/chromium_crates_io/vendor/jxl-v0_3/src/util/smallvec.rs",' "$BUILD_GN"
        fi
    else
        if grep -q "util/smallvec.rs" "$BUILD_GN" 2>/dev/null; then
            echo "  Removing smallvec.rs from BUILD.gn..."
            sed -i '/util\/smallvec\.rs/d' "$BUILD_GN"
        fi
    fi

    echo "  BUILD.gn synced."
}

setup() {
    echo "Setting up local jxl-rs symlinks..."

    if [ ! -d "$LOCAL_JXL" ]; then
        echo "ERROR: Local jxl-rs not found at $LOCAL_JXL"
        exit 1
    fi

    cd "$CHROMIUM_VENDOR"

    for entry in "${CRATES[@]}"; do
        chromium_name="${entry%%:*}"
        local_name="${entry##*:}"

        if [ -L "$chromium_name" ]; then
            echo "  $chromium_name is already a symlink, skipping backup"
        elif [ -d "$chromium_name" ]; then
            echo "  Backing up $chromium_name -> $chromium_name.bak"
            mv "$chromium_name" "$chromium_name.bak"
        fi

        if [ ! -L "$chromium_name" ]; then
            echo "  Symlinking $LOCAL_JXL/$local_name -> $chromium_name"
            ln -s "$LOCAL_JXL/$local_name" "$chromium_name"
        fi
    done

    # Clean build cache to avoid stale proc_macro issues
    clean_build_cache

    # Fix BUILD.gn for upstream compatibility
    fix_build_gn

    # Regenerate ninja files for the new symlinks
    regen_ninja

    echo ""
    echo "Done! Local jxl-rs is now active."
    echo "Build with: autoninja -C out/Default blink_platform_unittests"
    echo "Test with:  out/Default/blink_platform_unittests --gtest_filter='*JXL*'"
}

restore() {
    echo "Restoring original vendored jxl-rs..."

    cd "$CHROMIUM_VENDOR"

    for entry in "${CRATES[@]}"; do
        chromium_name="${entry%%:*}"

        if [ -L "$chromium_name" ]; then
            echo "  Removing symlink $chromium_name"
            rm "$chromium_name"
        fi

        if [ -d "$chromium_name.bak" ]; then
            echo "  Restoring $chromium_name.bak -> $chromium_name"
            mv "$chromium_name.bak" "$chromium_name"
        fi
    done

    # Clean build cache
    clean_build_cache

    # Regenerate ninja files
    regen_ninja

    echo ""
    echo "Done! Original vendored jxl-rs restored."
}

status() {
    echo "Current status:"
    cd "$CHROMIUM_VENDOR"

    for entry in "${CRATES[@]}"; do
        chromium_name="${entry%%:*}"

        if [ -L "$chromium_name" ]; then
            target=$(readlink "$chromium_name")
            echo "  $chromium_name -> $target (LOCAL)"
        elif [ -d "$chromium_name" ]; then
            echo "  $chromium_name (vendored)"
        else
            echo "  $chromium_name (MISSING!)"
        fi
    done

    echo ""
    if [ -L "$CHROMIUM_VENDOR/jxl-v0_3" ]; then
        echo "Local jxl-rs branch:"
        cd "$LOCAL_JXL" && git branch --show-current && git log --oneline -1
    fi
}

clean() {
    clean_build_cache
    echo "Done!"
}

bisect() {
    local commit="$1"
    if [ -z "$commit" ]; then
        echo "Usage: $0 bisect <commit>"
        echo ""
        echo "Switches local jxl-rs to the specified commit and rebuilds."
        echo "After testing, mark as good/bad:"
        echo "  cd ~/jxl-rs && git bisect good"
        echo "  cd ~/jxl-rs && git bisect bad"
        echo "Then run: $0 bisect \$(cd ~/jxl-rs && git rev-parse HEAD)"
        exit 1
    fi

    echo "Switching to commit: $commit"
    cd "$LOCAL_JXL" && git checkout "$commit"

    echo ""
    echo "Current commit:"
    cd "$LOCAL_JXL" && git log --oneline -1

    # Clean and sync
    clean_build_cache
    fix_build_gn
    regen_ninja

    echo ""
    echo "Ready to build and test!"
    echo "After testing, run:"
    echo "  cd ~/jxl-rs && git bisect good   # if no bug"
    echo "  cd ~/jxl-rs && git bisect bad    # if bug present"
    echo "Then: ~/use-local-jxl-rs.sh bisect \$(cd ~/jxl-rs && git rev-parse HEAD)"
}

override() {
    echo "Copying local jxl-rs to vendor directory (for committing to Chromium)..."

    if [ ! -d "$LOCAL_JXL" ]; then
        echo "ERROR: Local jxl-rs not found at $LOCAL_JXL"
        exit 1
    fi

    cd "$CHROMIUM_VENDOR"

    for entry in "${CRATES[@]}"; do
        chromium_name="${entry%%:*}"
        local_name="${entry##*:}"

        # Remove existing symlink or directory
        if [ -L "$chromium_name" ]; then
            echo "  Removing symlink $chromium_name"
            rm "$chromium_name"
        elif [ -d "$chromium_name" ]; then
            echo "  Removing existing $chromium_name"
            rm -rf "$chromium_name"
        fi

        # Copy from local jxl-rs
        echo "  Copying $LOCAL_JXL/$local_name -> $chromium_name"
        cp -r "$LOCAL_JXL/$local_name" "$chromium_name"

        # Remove .git directory if copied
        rm -rf "$chromium_name/.git" 2>/dev/null || true
    done

    # Clean build cache
    clean_build_cache

    # Fix BUILD.gn for upstream compatibility
    fix_build_gn

    # Regenerate ninja files
    regen_ninja

    echo ""
    echo "Done! Local jxl-rs copied to vendor directory."
    echo "Files are now ready to be committed to Chromium."
    echo ""
    echo "From ~/jxl-rs:"
    cd "$LOCAL_JXL" && git log --oneline -1
}

case "${1:-status}" in
    setup)
        setup
        ;;
    restore)
        restore
        ;;
    status)
        status
        ;;
    clean)
        clean
        ;;
    bisect)
        bisect "$2"
        ;;
    override)
        override
        ;;
    *)
        echo "Usage: $0 [setup|restore|status|clean|bisect <commit>|override]"
        echo ""
        echo "  setup           - Switch to local jxl-rs at ~/jxl-rs (symlinks)"
        echo "  restore         - Restore original vendored jxl-rs"
        echo "  status          - Show current state (default)"
        echo "  clean           - Clean jxl build artifacts"
        echo "  bisect <commit> - Switch to specific commit and sync BUILD.gn"
        echo "  override        - Copy local jxl-rs to vendor (for committing)"
        exit 1
        ;;
esac