Add infrastructure to build WebAssembly static libs via wasm-vips (#205)

Co-authored-by: Ingvar Stepanyan <[email protected]>

.github/workflows/build-release.yml

@@ -28,6 +28,7 @@ jobs:
           - 'linuxmusl-x64'
           - 'linuxmusl-arm64v8'
           - 'linux-s390x'
+          - 'wasm32'
           - 'win32-ia32'
           - 'win32-x64'
           - 'win32-arm64v8'

.gitignore

@@ -1,7 +1,9 @@
 libvips*
 *.log
+build/wasm-vips-*
 deps/
 target/
 npm/*/*
 !npm/*/package.json
+!npm/dev-wasm32/THIRD-PARTY-NOTICES.md
 npm/img-sharp-libvips-*.tgz

README.md

@@ -40,6 +40,13 @@ The dylib files are compiled within the same build script as Linux.
 
 Dependency paths are modified to use the relative `@rpath` with `install_name_tool`.
 
+### WebAssembly
+
+The scripts from [wasm-vips](https://github.com/kleisauke/wasm-vips)
+are [used to compile](build/wasm.sh) libvips and its dependencies
+as static Wasm libraries ready for further compilation into a single,
+statically-linked sharp shared library.
+
 ## Licences
 
 These scripts are licensed under the terms of the [Apache 2.0 Licence](LICENSE).

build.sh

@@ -79,6 +79,12 @@ if ! [ -x "$(command -v docker)" ]; then
   exit 1
 fi
 
+# WebAssembly
+if [ "$PLATFORM" == "wasm32" ]; then
+  ./build/wasm.sh "${VERSION_VIPS}"
+  exit 0
+fi
+
 # Update base images
 for baseimage in alpine:3.15 amazonlinux:2 debian:bullseye debian:buster; do
   docker pull $baseimage

build/wasm.sh

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+set -e
+
+if [ $# -lt 1 ]; then
+  echo
+  echo "Usage: $0 VERSION_VIPS [VERSION_WASM_VIPS]"
+  echo "Use wasm-vips to build wasm32 static libraries for libvips and its dependencies"
+  echo
+  echo "Please specify the libvips VERSION_VIPS, e.g. 8.15.0"
+  echo "Optionally provide a specific VERSION_WASM_VIPS commit, e.g. abc1234"
+  echo
+  exit 1
+fi
+VERSION_VIPS="$1"
+VERSION_WASM_VIPS="${2:-56f151b}" # TODO: fetch latest wasm-vips commit as default
+
+DIR="wasm-vips-${VERSION_WASM_VIPS}"
+TAG="wasm-vips:${VERSION_WASM_VIPS}"
+
+echo "Using ${TAG} to build libvips ${VERSION_VIPS}"
+cd "${0%/*}"
+
+# Download specific version of wasm-vips
+if [ ! -d "$DIR" ]; then
+  mkdir "${DIR}"
+  curl -Ls https://github.com/kleisauke/wasm-vips/archive/${VERSION_WASM_VIPS}.tar.gz | tar xzC "${DIR}" --strip-components=1
+fi
+
+# Check libvips versions match
+VERSION_VIPS_UPSTREAM=$(grep -Po "^VERSION_VIPS=\K[^ ]*" "${DIR}/build.sh")
+if [ "$VERSION_VIPS" != "$VERSION_VIPS_UPSTREAM" ]; then
+  echo "Expected libvips $VERSION_VIPS, found $VERSION_VIPS_UPSTREAM upstream" # TODO: modify build.sh on-the-fly?
+  exit 1
+fi
+
+# Create container with emscripten
+if [ -z "$(docker images -q ${TAG})" ]; then
+  pushd "${DIR}"
+  docker build -t "${TAG}" .
+  popd
+fi
+
+# Build libvips and dependencies as static Wasm libraries via emscripten
+if [ ! -d "$DIR/build/target/lib" ]; then
+  docker run --rm -v "$PWD/${DIR}":/src "${TAG}" -c "./build.sh --disable-bindings --disable-modules --disable-jxl --enable-libvips-cpp"
+fi
+
+# Copy only the files we need
+cp -r --no-preserve=mode,ownership ${DIR}/build/target/{include,lib,versions.json} ../npm/dev-wasm32
+rm -r ../npm/dev-wasm32/lib/cmake

npm/dev-wasm32/THIRD-PARTY-NOTICES.md

@@ -0,0 +1,31 @@
+# Third-party notices
+
+This software contains third-party libraries
+used under the terms of the following licences:
+
+| Library       | Used under the terms of                                                                                   |
+|---------------|-----------------------------------------------------------------------------------------------------------|
+| aom           | BSD 2-Clause + [Alliance for Open Media Patent License 1.0](https://aomedia.org/license/patent-license/)  |
+| cgif          | MIT Licence                                                                                               |
+| expat         | MIT Licence                                                                                               |
+| glib          | LGPLv3                                                                                                    |
+| highway       | Apache-2.0 License, BSD 3-Clause                                                                          |
+| lcms          | MIT Licence                                                                                               |
+| libexif       | LGPLv3                                                                                                    |
+| libffi        | MIT Licence                                                                                               |
+| libheif       | LGPLv3                                                                                                    |
+| libimagequant | [BSD 2-Clause](https://github.com/lovell/libimagequant/blob/main/COPYRIGHT)                               |
+| mozjpeg       | [zlib License, IJG License, BSD-3-Clause](https://github.com/mozilla/mozjpeg/blob/master/LICENSE.md)      |
+| libnsgif      | MIT Licence                                                                                               |
+| libspng       | [BSD 2-Clause, libpng License](https://github.com/randy408/libspng/blob/master/LICENSE)                   |
+| libtiff       | [libtiff License](https://gitlab.com/libtiff/libtiff/blob/master/LICENSE.md) (BSD-like)                   |
+| libvips       | LGPLv3                                                                                                    |
+| libwebp       | New BSD License                                                                                           |
+| resvg         | MPL-2.0 License                                                                                           |
+| zlib-ng       | [zlib Licence](https://github.com/zlib-ng/zlib-ng/blob/develop/LICENSE.md)                                |
+
+Use of libraries under the terms of the LGPLv3 is via the
+"any later version" clause of the LGPLv2 or LGPLv2.1.
+
+Please report any errors or omissions via
+https://github.com/lovell/sharp-libvips/issues/new

npm/dev-wasm32/package.json

@@ -0,0 +1,31 @@
+{
+  "name": "@img/sharp-libvips-dev-wasm32",
+  "version": "0.0.3",
+  "description": "Header files and static wasm32 libraries for libvips and dependencies to build sharp as wasm32",
+  "author": "Lovell Fuller <[email protected]>",
+  "homepage": "https://sharp.pixelplumbing.com",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/lovell/sharp-libvips.git",
+    "directory": "npm/dev-wasm32"
+  },
+  "license": "LGPL-3.0-or-later",
+  "funding": {
+    "url": "https://opencollective.com/libvips"
+  },
+  "preferUnplugged": true,
+  "publishConfig": {
+    "access": "public"
+  },
+  "files": [
+    "include",
+    "lib",
+    "versions.json"
+  ],
+  "type": "commonjs",
+  "exports": {
+    "./include": "./include/index.js",
+    "./lib": "./lib/index.js",
+    "./versions": "./versions.json"
+  }
+}

npm/package.json

@@ -4,6 +4,7 @@
   "private": "true",
   "workspaces": [
     "dev",
+    "dev-wasm32",
     "darwin-x64",
     "darwin-arm64",
     "linux-arm",

npm/populate.sh

@@ -38,10 +38,10 @@ generate_index() {
 
 remove_unused() {
   PACKAGE="$1"
-  if [ "$PACKAGE" != "dev" ]; then
+  if [[ "$PACKAGE" != "dev"* ]]; then
     rm -r "npm/$PACKAGE/include"
+    rm "npm/$PACKAGE/THIRD-PARTY-NOTICES.md"
   fi
-  rm "npm/$PACKAGE/THIRD-PARTY-NOTICES.md"
 }
 
 # Download and extract per-platform binaries