Fix Asyncify and improve build process

Build system improvements:
- Add wasm-opt stub for Docker build to bypass asyncify in container
- Add apply-asyncify.sh script for host-side asyncify transformation
- Update build-pcbnew.sh to install wasm-opt stub and add EXPORTED_RUNTIME_METHODS
- Add --with-zlib=sys to wxWidgets configure for proper zlib linking
- Improve update-baseline-screenshots.sh to only copy new/significantly changed files

wxWidgets submodule update:
- Fix EM_JS to EM_ASYNC_JS for proper Asyncify registration

Test updates:
- Add new baseline screenshots for bitmapbuttons, dnd, gridrenderers, printpreview, specialized tests
- Add kicad-pcbnew initial screenshot
- Fix wxgrid-controls.png and wxgrid-dedicated-page.png (were showing errors)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docker/build.sh

@@ -11,11 +11,6 @@ set -e
 
 cd "$(dirname "$0")/.."
 
-# Get wasm-opt (downloads Binaryen v121 if not cached)
-echo "Checking wasm-opt..."
-WASM_OPT=$(./scripts/common/get-wasm-opt.sh)
-echo "Using: ${WASM_OPT}"
-
 # Start container if not running
 docker compose -f docker/docker-compose.yml up -d
 
@@ -29,21 +24,8 @@ docker compose -f docker/docker-compose.yml exec kicad-wasm-builder \
     bash -c "mkdir -p /workspace/output && cp /workspace/build-wasm/kicad-pcbnew/pcbnew/pcbnew.{js,wasm,wasm.map,worker.js} /workspace/output/ 2>/dev/null || cp /workspace/build-wasm/kicad-pcbnew/pcbnew/pcbnew.{js,wasm} /workspace/output/"
 
 # Apply asyncify transformation on host
-# This is done on the host because wasm-opt --asyncify needs 50GB+ RAM for KiCad,
-# which exceeds typical Docker memory limits
-echo ""
-echo "Applying asyncify transformation on host..."
-echo "This may take several minutes and use significant RAM..."
-
-# Asyncify import patterns (functions that trigger async suspension)
-# - env.invoke_* : Exception handling trampolines
-# - env.__asyncjs__* : EM_ASYNC_JS functions
-ASYNCIFY_IMPORTS="env.invoke_*,env.__asyncjs__*"
-
-"${WASM_OPT}" --asyncify \
-    --pass-arg=asyncify-imports@${ASYNCIFY_IMPORTS} \
-    --pass-arg=asyncify-propagate-addlist \
-    output/pcbnew.wasm -o output/pcbnew.wasm
+# This is done on the host because wasm-opt --asyncify needs significant RAM
+./scripts/common/apply-asyncify.sh output/pcbnew.wasm output/pcbnew.wasm
 
 echo ""
 echo "Build complete. Output files in ./output/"

scripts/build-wxuniversal-wasm.sh

@@ -98,6 +98,7 @@ emconfigure "$WX_SOURCE/configure" \
     --disable-xlocale \
     --with-cxx=17 \
     --enable-utf8 \
+    --with-zlib=sys \
     ${WX_CONFIGURE_DEBUG}
 
 # Build PCRE first to avoid race condition with parallel builds

scripts/common/apply-asyncify.sh

@@ -0,0 +1,60 @@
+#!/bin/bash
+# Apply asyncify transformation to KiCad WASM
+#
+# Usage: ./scripts/common/apply-asyncify.sh <input.wasm> <output.wasm>
+#
+# This script is called by docker/build.sh but can also be run standalone
+# for debugging asyncify issues.
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(cd "${SCRIPT_DIR}/../.." && pwd)"
+
+# Get wasm-opt path
+WASM_OPT=$("${SCRIPT_DIR}/get-wasm-opt.sh")
+
+INPUT_WASM="${1:-output/pcbnew.wasm}"
+OUTPUT_WASM="${2:-${INPUT_WASM}}"
+
+if [ ! -f "${INPUT_WASM}" ]; then
+    echo "ERROR: Input file not found: ${INPUT_WASM}"
+    exit 1
+fi
+
+echo "Applying asyncify transformation..."
+echo "  Input:  ${INPUT_WASM}"
+echo "  Output: ${OUTPUT_WASM}"
+echo "  Tool:   ${WASM_OPT}"
+
+# Asyncify import patterns (functions that trigger async suspension)
+# - env.invoke_* : Exception handling trampolines
+# - env.__asyncjs__* : EM_ASYNC_JS functions (like startModal())
+ASYNCIFY_IMPORTS="env.invoke_*,env.__asyncjs__*"
+
+# Functions to exclude from asyncify instrumentation
+# These are large functions that inflate beyond V8's 7.65MB function limit
+# The names must match exactly as they appear in the WASM (C++ mangled names)
+ASYNCIFY_REMOVE=$(cat << 'REMOVELIST'
+COLOR_SETTINGS::COLOR_SETTINGS(wxString const&, bool)
+BuildBitmapInfo(std::__2::unordered_map<BITMAPS, std::__2::vector<BITMAP_INFO, std::__2::allocator<BITMAP_INFO>>, std::__2::hash<BITMAPS>, std::__2::equal_to<BITMAPS>, std::__2::allocator<std::__2::pair<BITMAPS const, std::__2::vector<BITMAP_INFO, std::__2::allocator<BITMAP_INFO>>>>>&)
+match
+REMOVELIST
+)
+
+# Convert newlines to commas for the removelist
+ASYNCIFY_REMOVE_ARG=$(echo "${ASYNCIFY_REMOVE}" | tr '\n' ',' | sed 's/,$//')
+
+echo ""
+echo "Running wasm-opt --asyncify..."
+echo "This may take several minutes and use significant RAM..."
+
+"${WASM_OPT}" --asyncify \
+    "--pass-arg=asyncify-imports@${ASYNCIFY_IMPORTS}" \
+    "--pass-arg=asyncify-removelist@${ASYNCIFY_REMOVE_ARG}" \
+    --pass-arg=asyncify-propagate-addlist \
+    "${INPUT_WASM}" -o "${OUTPUT_WASM}"
+
+echo ""
+echo "Asyncify complete: ${OUTPUT_WASM}"
+ls -lh "${OUTPUT_WASM}"

scripts/kicad/build-pcbnew.sh

@@ -157,6 +157,19 @@ emar rcs "${STUBS_BUILD}/libcurl_stub.a" "${STUBS_BUILD}/curl_stub.o"
 
 log_info "Stub libraries built"
 
+# Step 6.2: Replace Emscripten's wasm-opt with stub to bypass asyncify transformation
+# This allows Emscripten to generate JS with Asyncify runtime, but we run the real
+# wasm-opt --asyncify on the host where more RAM is available (needs 50GB+ for KiCad)
+EMSDK_WASM_OPT="/emsdk/upstream/bin/wasm-opt"
+if [ -f "${EMSDK_WASM_OPT}" ] && [ ! -f "${EMSDK_WASM_OPT}.real" ]; then
+    log_info "Backing up real wasm-opt..."
+    mv "${EMSDK_WASM_OPT}" "${EMSDK_WASM_OPT}.real"
+fi
+# Always copy the latest stub (in case it was updated)
+cp "${STUBS_DIR}/wasm-opt-stub.sh" "${EMSDK_WASM_OPT}"
+chmod +x "${EMSDK_WASM_OPT}"
+log_info "wasm-opt stub installed (asyncify will run on host)"
+
 # Step 6.5: Verify WASM support is in KiCad fork
 # The kicad submodule should already have WASM port detection and kiplatform support
 KICAD_CMAKE="${KICAD_DIR}/CMakeLists.txt"
@@ -184,7 +197,7 @@ emcmake cmake "${KICAD_DIR}" \
     -DCMAKE_POLICY_VERSION_MINIMUM=3.5 \
     -DCMAKE_CXX_FLAGS="${EXTRA_FLAGS} -pthread -sUSE_ZLIB=1 -DKICAD_USE_PLATFORM_WASM=1 -I${SYSROOT}/include" \
     -DCMAKE_C_FLAGS="${EXTRA_FLAGS} -pthread -sUSE_ZLIB=1 -I${SYSROOT}/include" \
-    -DCMAKE_EXE_LINKER_FLAGS="${LINKER_DEBUG_FLAGS} -pthread -sUSE_ZLIB=1 -sUSE_PTHREADS=1 -sPTHREAD_POOL_SIZE=4 -sALLOW_MEMORY_GROWTH=1 -sINITIAL_MEMORY=256MB -sMAXIMUM_MEMORY=4GB -L${SYSROOT}/lib ${STUBS_BUILD}/libgit2_stub.a ${STUBS_BUILD}/libcurl_stub.a" \
+    -DCMAKE_EXE_LINKER_FLAGS="${LINKER_DEBUG_FLAGS} -pthread -sUSE_ZLIB=1 -sASYNCIFY=1 -sASYNCIFY_STACK_SIZE=65536 -sUSE_PTHREADS=1 -sPTHREAD_POOL_SIZE=4 -sALLOW_MEMORY_GROWTH=1 -sINITIAL_MEMORY=256MB -sMAXIMUM_MEMORY=4GB -sEXPORTED_RUNTIME_METHODS=['ccall','cwrap','UTF8ToString','stringToUTF8','lengthBytesUTF8'] -L${SYSROOT}/lib ${STUBS_BUILD}/libgit2_stub.a ${STUBS_BUILD}/libcurl_stub.a" \
     -DCMAKE_PREFIX_PATH="${SYSROOT};${WX_BUILD}" \
     -DwxWidgets_CONFIG_EXECUTABLE="${WX_BUILD}/wx-config" \
     \

scripts/update-baseline-screenshots.sh

@@ -1,11 +1,28 @@
 #!/bin/bash
 # Update baseline screenshots from test results
+# Only copies:
+#   - NEW screenshots (not in baseline)
+#   - Screenshots with SIGNIFICANT differences (>5% size change) when --all flag used
+#
+# Usage:
+#   ./update-baseline-screenshots.sh          # Only copy NEW screenshots
+#   ./update-baseline-screenshots.sh --all    # Copy new + significantly different
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 TESTS_DIR="$SCRIPT_DIR/../tests"
 SOURCE_DIR="$TESTS_DIR/test-results"
 DEST_DIR="$TESTS_DIR/baseline-screenshots"
 
+COPY_ALL=0
+THRESHOLD=5  # Percent threshold for "significant" difference
+
+if [ "$1" = "--all" ]; then
+    COPY_ALL=1
+    echo "Mode: Copy NEW + SIGNIFICANTLY DIFFERENT screenshots"
+else
+    echo "Mode: Copy NEW screenshots only (use --all to include significant changes)"
+fi
+
 if [ ! -d "$SOURCE_DIR" ]; then
     echo "Error: test-results directory not found at $SOURCE_DIR"
     echo "Run 'npm test' first to generate screenshots"
@@ -14,15 +31,45 @@ fi
 
 mkdir -p "$DEST_DIR"
 
-count=$(ls -1 "$SOURCE_DIR"/*.png 2>/dev/null | wc -l)
-if [ "$count" -eq 0 ]; then
-    echo "No screenshots found in $SOURCE_DIR"
-    exit 1
+new_count=0
+updated_count=0
+
+for src_file in "$SOURCE_DIR"/*.png; do
+    [ -f "$src_file" ] || continue
+
+    filename=$(basename "$src_file")
+    dest_file="$DEST_DIR/$filename"
+
+    if [ ! -f "$dest_file" ]; then
+        # NEW: Screenshot doesn't exist in baseline
+        echo "NEW: $filename"
+        cp "$src_file" "$dest_file"
+        ((new_count++))
+    elif [ $COPY_ALL -eq 1 ]; then
+        # Check if significantly different
+        src_size=$(stat -f%z "$src_file" 2>/dev/null || stat -c%s "$src_file")
+        dest_size=$(stat -f%z "$dest_file" 2>/dev/null || stat -c%s "$dest_file")
+
+        if [ "$dest_size" -eq 0 ]; then
+            diff_pct=100
+        else
+            diff=$((src_size - dest_size))
+            diff=${diff#-}  # Absolute value
+            diff_pct=$((diff * 100 / dest_size))
+        fi
+
+        if [ "$diff_pct" -ge "$THRESHOLD" ]; then
+            echo "UPDATED ($diff_pct% diff): $filename"
+            cp "$src_file" "$dest_file"
+            ((updated_count++))
+        fi
+    fi
+done
+
+echo ""
+echo "=== Summary ==="
+echo "New screenshots added: $new_count"
+if [ $COPY_ALL -eq 1 ]; then
+    echo "Significantly changed: $updated_count"
 fi
-
-echo "Copying $count screenshots to baseline..."
-cp "$SOURCE_DIR"/*.png "$DEST_DIR/"
-
-echo "Updated baseline screenshots:"
-ls -1 "$DEST_DIR"/*.png | wc -l
-echo "screenshots in $DEST_DIR"
+echo "Total in baseline: $(ls -1 "$DEST_DIR"/*.png 2>/dev/null | wc -l | tr -d ' ')"

wasm/stubs/wasm-opt-stub.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+# Stub wasm-opt that does nothing
+# This allows Emscripten to generate Asyncify JS runtime without running the actual transformation
+# The real wasm-opt --asyncify is run on the host where more RAM is available
+
+# Handle --version query from Emscripten
+if [[ "$1" == "--version" ]]; then
+    echo "wasm-opt version 121 (version_121)"
+    exit 0
+fi
+
+# Find the output file argument (-o)
+OUTPUT=""
+INPUT=""
+PREV_ARG=""
+
+for arg in "$@"; do
+    if [ "$PREV_ARG" = "-o" ]; then
+        OUTPUT="$arg"
+    elif [[ "$arg" != -* ]] && [ -f "$arg" ]; then
+        INPUT="$arg"
+    fi
+    PREV_ARG="$arg"
+done
+
+# If we have both input and output, copy input to output
+if [ -n "$INPUT" ] && [ -n "$OUTPUT" ] && [ "$INPUT" != "$OUTPUT" ]; then
+    cp "$INPUT" "$OUTPUT"
+fi
+
+# Exit successfully so Emscripten thinks wasm-opt ran
+exit 0

wxwidgets

@@ -1 +1 @@
-Subproject commit 40bf50fe4ee6938894464e6039acacb38d55a227
+Subproject commit 08794a9f579d5fcdc08085e18f25f108446f46f0