feat(wasi): add wasm32-wasi as a compile target

.github/actions/wasi/base/action.yml

@@ -0,0 +1,16 @@
+name: "Ubuntu base dependencies"
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install system dependencies
+      shell: bash
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y ninja-build wget
+    - name: Install CMake
+      shell: bash
+      run: |
+        wget -nv -O ./cmake_install.sh https://github.com/Kitware/CMake/releases/download/v3.28.0-rc5/cmake-3.28.0-rc5-linux-x86_64.sh
+        sudo bash ./cmake_install.sh --skip-license --prefix=/usr --exclude-subdir
+        rm -f ./cmake_install.sh

.github/actions/wasi/clang/action.yml

@@ -0,0 +1,17 @@
+name: "Ubuntu latest clang"
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install clang/llvm 17
+      shell: bash
+      run: |
+        sudo apt-add-repository 'deb https://apt.llvm.org/jammy llvm-toolchain-jammy-17 main'
+        sudo wget -qO /etc/apt/trusted.gpg.d/llvm.asc https://apt.llvm.org/llvm-snapshot.gpg.key
+        sudo apt-get update
+        sudo apt-get install -y -t llvm-toolchain-jammy-17 \
+            clang-17 llvm-17 lld-17 lldb-17 libc++-17-dev \
+            libc++abi-17-dev libclang-rt-17-dev
+        for f in /usr/lib/llvm-*/bin/*; do sudo ln -sf "$f" /usr/bin; done
+        sudo mkdir -p /usr/lib/llvm-17/lib/clang/17/lib/wasi
+        sudo chmod 0777 /usr/lib/llvm-17/lib/clang/17/lib/wasi

.github/ci.yaml

@@ -9,6 +9,7 @@ jobs:
       fail-fast: false
       matrix:
         target: [
+          { os: ubuntu-22.04, preset: wasm32-wasi-clang-static },
           { os: ubuntu-latest, preset: x64-linux-gcc-dynamic },
           { os: ubuntu-latest, preset: x86-linux-gcc-dynamic },
           { os: ubuntu-latest, preset: x64-linux-clang-dynamic },

.github/workflows/ci.yaml

@@ -9,6 +9,7 @@ jobs:
       fail-fast: false
       matrix:
         target: [
+          { os: ubuntu-22.04, preset: wasm32-wasi-clang-static },
           { os: ubuntu-latest, preset: x64-linux-gcc-dynamic },
           { os: ubuntu-latest, preset: x86-linux-gcc-dynamic },
           { os: ubuntu-latest, preset: x64-linux-clang-dynamic },
@@ -34,6 +35,15 @@ jobs:
     - uses: ./.github/actions/vcpkg-cache
 
     - name: CMake workflow
+      id: cmake-workflow
       shell: bash
       run: |
         cmake --workflow --preset ${{matrix.target.preset}}
+
+    - name: Upload vcpkg error logs
+      if: failure()
+      uses: actions/upload-artifact@v4
+      with:
+        name: logs-${{matrix.target.preset}}
+        path: |
+          /usr/local/share/vcpkg/**/*.log

CMakeLists.txt

@@ -9,5 +9,7 @@ list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake")
 
 add_subdirectory(src)
 
-enable_testing()
-add_subdirectory(tests)
+if (NOT WASI) 
+    enable_testing()
+    add_subdirectory(tests)
+endif()

CMakePresets.json

@@ -8,12 +8,14 @@
   "include": [
     "cmake/presets/arm64-darwin-gcc.json",
     "cmake/presets/arm64-darwin-clang.json",
+    "cmake/presets/wasm32-wasi-clang.json",
     "cmake/presets/x64-darwin-gcc.json",
     "cmake/presets/x64-darwin-clang.json",
-    "cmake/presets/x64-linux-gcc.json",
     "cmake/presets/x64-windows-clang.json",
     "cmake/presets/x64-windows-msvc.json",
     "cmake/presets/x86-linux-gcc.json",
+    "cmake/presets/x86-linux-clang.json",
+    "cmake/presets/x64-linux-gcc.json",
     "cmake/presets/x64-linux-clang.json"
   ]
 }

README.md

@@ -62,4 +62,17 @@ find_package(<PROJECT_NAME> CONFIG REQUIRED)
 target_link_libraries(<TARGET> PUBLIC <PROJECT_NAME>::<MODULE_NAME>)
 ```
 
-This will require that your library is published and installed via vcpkg or found locally by setting the `CMAKE_PREFIX_PATH` environment variable in your other project during configure.
+This will require that your library is published and installed via vcpkg or found locally by setting the `CMAKE_PREFIX_PATH` environment variable in your other project during configure.
+
+If you wish to expose parts of your library as a WebAssembly module, you can add the `WASM_EXPORT("<export_name>")` macro to any function you wish to expose in `src/wasm/interface.cpp`, and compile using the `wasm32-wasi-clang` preset. This will generate a minimal WebAssembly binary exposing your exported functions at `build/<PRESET>/src/wasm/<Debug|Release|RelWithDebInfo>/lib<PROJECT_NAME>.wasm`. This binary conforms to the [WASI WebAssembly standard](https://wasi.dev/), so it can be utilized in any WASI-supporting runtime like [`wasmer.io`](https://wasmer.io/)
+
+```sh
+wasmer run build/<PRESET>/src/cli/<Debug|Release|RelWithDebInfo>/<PROJECT_NAME>_cli
+
+# Prints:
+# <PROJECT_NAME> version: 0.0.1
+```
+
+> [!NOTE] 
+> Exposed functions with `WASM_EXPORT` currently only accept parameters and return values of numerical type. This is because the proposal for WebAssembly Interface Types has not yet been standardized, and until then, complex data-types cannot be sent over the runtime's ABI boundary. Complex data must be transferred via pointer into exported/shared memory.
+

cmake/Platform/WASI.cmake

@@ -0,0 +1 @@
+set(WASI 1)

cmake/presets/toolchains/wasi-sdk.json

@@ -0,0 +1,13 @@
+{
+  "version": 6,
+  "configurePresets": [
+    {
+      "name": "wasi-sdk",
+      "hidden": true,
+      "cacheVariables": {
+        "VCPKG_CHAINLOAD_TOOLCHAIN_FILE": "${sourceDir}/cmake/wasi-sdk/wasi-sdk.toolchain.cmake",
+        "VCPKG_OVERLAY_PORTS": "${sourceDir}/cmake/vcpkg/ports/wasm32-wasi"
+      }
+    }
+  ]
+}

cmake/presets/wasm32-wasi-clang.json

@@ -0,0 +1,41 @@
+{
+  "version": 6,
+  "include": [
+    "base.json",
+    "compilers/clang.json",
+    "toolchains/wasi-sdk.json"
+  ],
+  "configurePresets": [
+    {
+      "name": "wasm32-wasi-clang-static",
+      "inherits": [
+        "base",
+        "wasi-sdk",
+        "clang"
+      ],
+      "displayName": "WASM32 WASI clang static libs"
+    }
+  ],
+  "buildPresets": [
+    {
+      "name": "wasm32-wasi-clang-static",
+      "inherits": "base",
+      "configurePreset": "wasm32-wasi-clang-static"
+    }
+  ],
+  "workflowPresets": [
+    {
+      "name": "wasm32-wasi-clang-static",
+      "steps": [
+        {
+          "type": "configure",
+          "name": "wasm32-wasi-clang-static"
+        },
+        {
+          "type": "build",
+          "name": "wasm32-wasi-clang-static"
+        }
+      ]
+    }
+  ]
+}

cmake/vcpkg/ports/wasm32-wasi/fmt/001-fix-write-batch.patch

@@ -0,0 +1,13 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index f21cf45..691a632 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -157,7 +157,7 @@ if (MASTER_PROJECT AND CMAKE_GENERATOR MATCHES "Visual Studio")
+   join(netfxpath
+        "C:\\Program Files\\Reference Assemblies\\Microsoft\\Framework\\"
+        ".NETFramework\\v4.0")
+-  file(WRITE run-msbuild.bat "
++  file(WRITE ${CMAKE_BINARY_DIR}/run-msbuild.bat "
+     ${MSBUILD_SETUP}
+     ${CMAKE_MAKE_PROGRAM} -p:FrameworkPathOverride=\"${netfxpath}\" %*")
+ endif ()

cmake/vcpkg/ports/wasm32-wasi/fmt/002-disable-posix-fd.patch

@@ -0,0 +1,47 @@
+diff --git a/src/os.cc b/src/os.cc
+index 7813c433..b472f0a6 100644
+--- a/src/os.cc
++++ b/src/os.cc
+@@ -279,7 +279,7 @@ std::size_t file::write(const void* buffer, std::size_t count) {
+ file file::dup(int fd) {
+   // Don't retry as dup doesn't return EINTR.
+   // http://pubs.opengroup.org/onlinepubs/009695399/functions/dup.html
+-  int new_fd = FMT_POSIX_CALL(dup(fd));
++  int new_fd = -1;
+   if (new_fd == -1)
+     FMT_THROW(system_error(
+         errno, FMT_STRING("cannot duplicate file descriptor {}"), fd));
+@@ -287,8 +287,7 @@ file file::dup(int fd) {
+ }
+
+ void file::dup2(int fd) {
+-  int result = 0;
+-  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
++  int result = -1;
+   if (result == -1) {
+     FMT_THROW(system_error(
+         errno, FMT_STRING("cannot duplicate file descriptor {} to {}"), fd_,
+@@ -297,8 +296,7 @@ void file::dup2(int fd) {
+ }
+
+ void file::dup2(int fd, std::error_code& ec) noexcept {
+-  int result = 0;
+-  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
++  int result = -1;
+   if (result == -1) ec = std::error_code(errno, std::generic_category());
+ }
+
+@@ -335,11 +333,11 @@ pipe::pipe() {
+ #  ifdef _WIN32
+   // Make the default pipe capacity same as on Linux 2.6.11+.
+   enum { DEFAULT_CAPACITY = 65536 };
+-  int result = FMT_POSIX_CALL(pipe(fds, DEFAULT_CAPACITY, _O_BINARY));
++  int result = -1;
+ #  else
+   // Don't retry as the pipe function doesn't return EINTR.
+   // http://pubs.opengroup.org/onlinepubs/009696799/functions/pipe.html
+-  int result = FMT_POSIX_CALL(pipe(fds));
++  int result = -1;
+ #  endif
+   if (result != 0)
+     FMT_THROW(system_error(errno, FMT_STRING("cannot create pipe")));

cmake/vcpkg/ports/wasm32-wasi/fmt/README.md

@@ -0,0 +1 @@
+This overlay port is a direct copy from https://github.com/microsoft/vcpkg/tree/master/ports/fmt with modifications to allow compilation on wasm32-wasi as a target by removing POSIX filesystem calls.

cmake/vcpkg/ports/wasm32-wasi/fmt/portfile.cmake

@@ -0,0 +1,38 @@
+vcpkg_from_github(
+    OUT_SOURCE_PATH SOURCE_PATH
+    REPO fmtlib/fmt
+    REF "${VERSION}"
+    SHA512 27df90c681ec37e55625062a79e3b83589b6d7e94eff37a3b412bb8c1473f757a8adb727603acc9185c3490628269216843b7d7bd5a3cb37f0029da5d1495ffa
+    HEAD_REF master
+    PATCHES
+        001-fix-write-batch.patch
+        002-disable-posix-fd.patch
+)
+
+vcpkg_cmake_configure(
+    SOURCE_PATH "${SOURCE_PATH}"
+    OPTIONS
+        -DFMT_CMAKE_DIR=share/fmt
+        -DFMT_TEST=OFF
+        -DFMT_DOC=OFF
+)
+
+vcpkg_cmake_install()
+vcpkg_cmake_config_fixup()
+vcpkg_fixup_pkgconfig()
+vcpkg_copy_pdbs()
+
+if(VCPKG_LIBRARY_LINKAGE STREQUAL dynamic)
+    vcpkg_replace_string(${CURRENT_PACKAGES_DIR}/include/fmt/core.h
+        "defined(FMT_SHARED)"
+        "1"
+    )
+endif()
+
+file(REMOVE_RECURSE 
+    "${CURRENT_PACKAGES_DIR}/debug/include"
+    "${CURRENT_PACKAGES_DIR}/debug/share"
+)
+
+file(INSTALL "${CMAKE_CURRENT_LIST_DIR}/usage" DESTINATION "${CURRENT_PACKAGES_DIR}/share/${PORT}")
+vcpkg_install_copyright(FILE_LIST "${SOURCE_PATH}/LICENSE")

cmake/vcpkg/ports/wasm32-wasi/fmt/usage

@@ -0,0 +1,8 @@
+The package fmt provides CMake targets:
+
+    find_package(fmt CONFIG REQUIRED)
+    target_link_libraries(main PRIVATE fmt::fmt)
+
+    # Or use the header-only version
+    find_package(fmt CONFIG REQUIRED)
+    target_link_libraries(main PRIVATE fmt::fmt-header-only)

cmake/vcpkg/ports/wasm32-wasi/fmt/vcpkg.json

@@ -0,0 +1,17 @@
+{
+  "name": "fmt",
+  "version": "10.2.1",
+  "description": "Formatting library for C++. It can be used as a safe alternative to printf or as a fast alternative to IOStreams.",
+  "homepage": "https://github.com/fmtlib/fmt",
+  "license": "MIT",
+  "dependencies": [
+    {
+      "name": "vcpkg-cmake",
+      "host": true
+    },
+    {
+      "name": "vcpkg-cmake-config",
+      "host": true
+    }
+  ]
+}

cmake/vcpkg/triplets/wasm32-wasi.cmake

@@ -0,0 +1,9 @@
+set(VCPKG_TARGET_ARCHITECTURE wasm32)
+set(VCPKG_LIBRARY_LINKAGE static)
+set(VCPKG_CRT_LINKAGE static)
+
+set(VCPKG_CMAKE_SYSTEM_NAME WASI)
+set(VCPKG_CMAKE_SYSTEM_VERSION 1)
+set(VCPKG_CMAKE_SYSTEM_PROCESSOR wasm32)
+
+set(VCPKG_CHAINLOAD_TOOLCHAIN_FILE "${CMAKE_CURRENT_LIST_DIR}/../../wasi-sdk/wasi-sdk.toolchain.cmake")

cmake/vcpkg/triplets/x86-linux-clang-dynamic.cmake

@@ -3,7 +3,3 @@ set(VCPKG_CRT_LINKAGE dynamic)
 set(VCPKG_LIBRARY_LINKAGE dynamic)
 
 set(VCPKG_CMAKE_SYSTEM_NAME Linux)
-
-set(VCPKG_CXX_FLAGS -stdlib=libc++)
-set(VCPKG_C_FLAGS -stdlib=libc++)
-set(VCPKG_LINKER_FLAGS "-stdlib=libc++ -lc++abi")

cmake/wasi-sdk/wasi-sdk.toolchain.cmake

@@ -0,0 +1,52 @@
+include_guard(GLOBAL)
+
+cmake_minimum_required(VERSION 3.25)
+
+get_property(IN_TRY_COMPILE GLOBAL PROPERTY IN_TRY_COMPILE)
+
+if (IN_TRY_COMPILE)
+  return()
+endif()
+
+unset(IN_TRY_COMPILE)
+
+# Until Platform/WASI.cmake is upstream we need to inject the path to it
+# into CMAKE_MODULE_PATH.
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/..")
+
+include(${CMAKE_CURRENT_LIST_DIR}/wasi-sdk_bootstrap.cmake)
+wasi_sdk_bootstrap(
+  TAG wasi-sdk-21 
+  WASI_SYSROOT_OUTPUT CMAKE_SYSROOT
+)
+
+set(CMAKE_SYSTEM_NAME WASI)
+set(CMAKE_SYSTEM_VERSION 1)
+set(CMAKE_SYSTEM_PROCESSOR wasm32)
+set(triple wasm32-wasi)
+
+set(CMAKE_C_COMPILER clang)
+set(CMAKE_CXX_COMPILER clang++)
+set(CMAKE_ASM_COMPILER clang)
+set(CMAKE_AR llvm-ar)
+set(CMAKE_RANLIB llvm-ranlib)
+set(CMAKE_C_COMPILER_TARGET ${triple})
+set(CMAKE_CXX_COMPILER_TARGET ${triple})
+set(CMAKE_ASM_COMPILER_TARGET ${triple})
+
+# Don't look in the sysroot for executables to run during the build
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+# Only look in the sysroot (not in the host paths) for the rest
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
+
+set(CLANG_DEFAULT_RTLIB "compiler-rt")
+set(LIBCXX_USE_COMPILER_RT "YES")
+set(LIBCXXABI_USE_COMPILER_RT "YES")
+
+add_compile_options(
+  "-stdlib=libc++" 
+  "-fno-exceptions" 
+  "-D_WASI_EMULATED_SIGNAL"
+)