Enable _Concurrency for Embedded Swift with WASI (#79292)

WASI with Embedded Swift provides WASI-libc and libc++ headers necessary to build the `_Concurrency` module for Wasm. We now add `wasm32-unknown-wasip1-wasm` triple to `EMBEDDED_STDLIB_TARGET_TRIPLES` when `SWIFT_WASI_SYSROOT_PATH` is set, which builds the necessary stdlib slice.

---------

Co-authored-by: Yuta Saito <kateinoigakukun@gmail.com>

Author: MaxDesiatov

CMakeLists.txt

@@ -487,6 +487,9 @@ set(SWIFT_NATIVE_CLANG_TOOLS_PATH "" CACHE STRING
 set(SWIFT_NATIVE_SWIFT_TOOLS_PATH "" CACHE STRING
    "Path to the directory that contains Swift tools that are executable on the build machine")
 
+set(SWIFT_WASI_SYSROOT_PATH "" CACHE PATH
+  "Path to the directory that contains WASI Sysroot")
+
 option(SWIFT_STDLIB_ENABLE_SIB_TARGETS
        "Should we generate sib targets for the stdlib or not?"
        FALSE)

stdlib/public/CMakeLists.txt

@@ -155,7 +155,10 @@ option(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB_CROSS_COMPILING
 set(SWIFT_EMBEDDED_STDLIB_EXTRA_TARGET_TRIPLES "" CACHE STRING
     "List of extra target triples to build the embedded Swift standard library for")
 
-if((NOT SWIFT_HOST_VARIANT STREQUAL "macosx") AND (NOT SWIFT_HOST_VARIANT STREQUAL "linux") AND (NOT SWIFT_HOST_VARIANT STREQUAL "windows"))
+if((NOT SWIFT_HOST_VARIANT STREQUAL "macosx") AND
+  (NOT SWIFT_HOST_VARIANT STREQUAL "linux") AND
+  (NOT SWIFT_HOST_VARIANT STREQUAL "wasi") AND
+  (NOT SWIFT_HOST_VARIANT STREQUAL "windows"))
   set(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB FALSE)
 elseif(BOOTSTRAPPING_MODE STREQUAL "OFF")
   set(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB FALSE)
@@ -168,68 +171,76 @@ endif()
 set(EMBEDDED_STDLIB_TARGET_TRIPLES)
 
 if(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB_CROSS_COMPILING)
-  if("ARM" IN_LIST LLVM_TARGETS_TO_BUILD)
+  if(SWIFT_WASI_SYSROOT_PATH)
+    # Don't attempt to build any other Embedded Swift stdlib triples
+    # when building for WASI.
     list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
-      # arch    module_name               target triple
-      "armv6    armv6-apple-none-macho    armv6-apple-none-macho"
-      "armv6m   armv6m-apple-none-macho   armv6m-apple-none-macho"
-      "armv7    armv7-apple-none-macho    armv7-apple-none-macho"
-      "armv7m   armv7m-apple-none-macho   armv7m-apple-none-macho"
-      "armv7em  armv7em-apple-none-macho  armv7em-apple-none-macho"
+      "wasm32    wasm32-unknown-wasip1  wasm32-unknown-wasip1"
     )
-  endif()
-  if("AArch64" IN_LIST LLVM_TARGETS_TO_BUILD)
-    list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
-      "arm64    arm64-apple-none-macho    arm64-apple-none-macho"
-      "arm64e   arm64e-apple-none-macho   arm64e-apple-none-macho"
-      "arm64    arm64-apple-ios           arm64-apple-ios18"
-      "arm64e   arm64e-apple-ios          arm64e-apple-ios18"
-    )
-  endif()
+  else()
+    if("ARM" IN_LIST LLVM_TARGETS_TO_BUILD)
+      list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
+        # arch    module_name               target triple
+        "armv6    armv6-apple-none-macho    armv6-apple-none-macho"
+        "armv6m   armv6m-apple-none-macho   armv6m-apple-none-macho"
+        "armv7    armv7-apple-none-macho    armv7-apple-none-macho"
+        "armv7m   armv7m-apple-none-macho   armv7m-apple-none-macho"
+        "armv7em  armv7em-apple-none-macho  armv7em-apple-none-macho"
+      )
+    endif()
+    if("AArch64" IN_LIST LLVM_TARGETS_TO_BUILD)
+      list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
+        "arm64    arm64-apple-none-macho    arm64-apple-none-macho"
+        "arm64e   arm64e-apple-none-macho   arm64e-apple-none-macho"
+        "arm64    arm64-apple-ios           arm64-apple-ios18"
+        "arm64e   arm64e-apple-ios          arm64e-apple-ios18"
+      )
+    endif()
+
+    # the following are all ELF targets
+    if("ARM" IN_LIST LLVM_TARGETS_TO_BUILD)
+      list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
+        "armv4t   armv4t-none-none-eabi     armv4t-none-none-eabi"
+        "armv6    armv6-none-none-eabi      armv6-none-none-eabi"
+        "armv6m   armv6m-none-none-eabi     armv6m-none-none-eabi"
+        "armv7    armv7-none-none-eabi      armv7-none-none-eabi"
+        "armv7em  armv7em-none-none-eabi    armv7em-none-none-eabi"
+      )
+    endif()
+    if("AArch64" IN_LIST LLVM_TARGETS_TO_BUILD)
+      list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
+        "aarch64  aarch64-none-none-elf     aarch64-none-none-elf"
+      )
+    endif()
+    if("RISCV" IN_LIST LLVM_TARGETS_TO_BUILD)
+      list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
+        "riscv32  riscv32-none-none-eabi    riscv32-none-none-eabi"
+        "riscv64  riscv64-none-none-eabi    riscv64-none-none-eabi"
+      )
+    endif()
+    if("X86" IN_LIST LLVM_TARGETS_TO_BUILD)
+      list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
+        "i686    i686-unknown-none-elf       i686-unknown-none-elf"
+        "x86_64  x86_64-unknown-none-elf     x86_64-unknown-none-elf"
+      )
+    endif()
 
-  # the following are all ELF targets
-  if("ARM" IN_LIST LLVM_TARGETS_TO_BUILD)
-    list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
-      "armv4t   armv4t-none-none-eabi     armv4t-none-none-eabi"
-      "armv6    armv6-none-none-eabi      armv6-none-none-eabi"
-      "armv6m   armv6m-none-none-eabi     armv6m-none-none-eabi"
-      "armv7    armv7-none-none-eabi      armv7-none-none-eabi"
-      "armv7em  armv7em-none-none-eabi    armv7em-none-none-eabi"
-    )
-  endif()
-  if("AArch64" IN_LIST LLVM_TARGETS_TO_BUILD)
-    list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
-      "aarch64  aarch64-none-none-elf     aarch64-none-none-elf"
-    )
-  endif()
-  if("RISCV" IN_LIST LLVM_TARGETS_TO_BUILD)
-    list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
-      "riscv32  riscv32-none-none-eabi    riscv32-none-none-eabi"
-      "riscv64  riscv64-none-none-eabi    riscv64-none-none-eabi"
-    )
-  endif()
-  if("X86" IN_LIST LLVM_TARGETS_TO_BUILD)
-    list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
-      "i686    i686-unknown-none-elf       i686-unknown-none-elf"
-      "x86_64  x86_64-unknown-none-elf     x86_64-unknown-none-elf"
-    )
-  endif()
+    if("WebAssembly" IN_LIST LLVM_TARGETS_TO_BUILD)
+      list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
+        "wasm32    wasm32-unknown-none-wasm    wasm32-unknown-none-wasm"
+        "wasm64    wasm64-unknown-none-wasm    wasm64-unknown-none-wasm"
+      )
+    endif()
 
-  if("WebAssembly" IN_LIST LLVM_TARGETS_TO_BUILD)
-    list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
-      "wasm32    wasm32-unknown-none-wasm    wasm32-unknown-none-wasm"
-      "wasm64    wasm64-unknown-none-wasm    wasm64-unknown-none-wasm"
-    )
+    if("AVR" IN_LIST LLVM_TARGETS_TO_BUILD)
+      list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
+        "avr  avr-none-none-elf    avr-none-none-elf"
+      )
+    endif()
   endif()
-
-  if("AVR" IN_LIST LLVM_TARGETS_TO_BUILD)
-    list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
-      "avr  avr-none-none-elf    avr-none-none-elf"
-    )
-  endif()  
 endif()
 
-if(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB)
+if(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB AND NOT SWIFT_WASI_SYSROOT_PATH)
   if (SWIFT_HOST_VARIANT STREQUAL "linux")
     list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
       "${SWIFT_HOST_VARIANT_ARCH} ${SWIFT_HOST_VARIANT_ARCH}-unknown-linux-gnu ${SWIFT_HOST_VARIANT_ARCH}-unknown-linux-gnu"

stdlib/public/Concurrency/CMakeLists.txt

@@ -260,8 +260,15 @@ if(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB AND SWIFT_SHOULD_BUILD_EMBEDDED_CONCURRENC
       if("${mod}" MATCHES "armv6m")
         continue()
       endif()
-      set(extra_c_compile_flags -D__MACH__ -D__APPLE__ -ffreestanding -stdlib=libc++)
-      set(extra_swift_compile_flags -Xcc -D__MACH__ -Xcc -D__APPLE__ -Xcc -ffreestanding)
+
+      if("${mod}" MATCHES "-macos$")
+        set(extra_c_compile_flags -D__MACH__ -D__APPLE__ -ffreestanding -stdlib=libc++)
+        set(extra_swift_compile_flags -Xcc -D__MACH__ -Xcc -D__APPLE__ -Xcc -ffreestanding)
+      endif()
+
+    elseif (SWIFT_HOST_VARIANT STREQUAL "wasi")
+      set(extra_c_compile_flags)
+      set(extra_swift_compile_flags)
     endif()
 
     set(SWIFT_SDK_embedded_THREADING_PACKAGE none)
@@ -304,7 +311,10 @@ if(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB AND SWIFT_SHOULD_BUILD_EMBEDDED_CONCURRENC
       COMPONENT "stdlib"
       PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
       )
-    set_property(TARGET embedded-concurrency-${mod} PROPERTY OSX_ARCHITECTURES "${arch}")
+
+    if(NOT "${arch}" MATCHES "wasm32")
+      set_property(TARGET embedded-concurrency-${mod} PROPERTY OSX_ARCHITECTURES "${arch}")
+    endif()
     add_dependencies(embedded-concurrency embedded-concurrency-${mod})
 
     # lib/swift/embedded/<triple>/libswift_ConcurrencyDefaultExecutor.a

utils/build-script-impl

@@ -1639,13 +1639,6 @@ for host in "${ALL_HOSTS[@]}"; do
                     )
                 fi
 
-                if [[ ! "${SKIP_BUILD_WASM}" ]]; then
-                    cmake_options=(
-                        "${cmake_options[@]}"
-                        -DSWIFT_WASI_SYSROOT_PATH:STRING="${WASI_SYSROOT}"
-                    )
-                fi
-
                 if [[ $(is_cross_tools_host ${host}) && "${host}" == "openbsd-"* && -n "${OPENBSD_USE_TOOLCHAIN_FILE}" ]]; then
                     cmake_options=(
                         "${cmake_options[@]}"
@@ -2503,7 +2496,7 @@ for host in "${ALL_HOSTS[@]}"; do
                   cmake_options=(
                     -DENABLE_SWIFT=YES
                     ${cmake_options[@]}
-                    
+
                     -DCMAKE_BUILD_TYPE:STRING="${LIBDISPATCH_BUILD_TYPE}"
                     -DCMAKE_C_COMPILER:PATH="${CLANG_BIN}/clang"
                     -DCMAKE_CXX_COMPILER:PATH="${CLANG_BIN}/clang++"

utils/swift_build_support/swift_build_support/products/wasisysroot.py

@@ -62,6 +62,7 @@ def _build(self, host_target, thread_model='single', target_triple='wasm32-wasi'
         # check-symbols. The directory is required during sysroot installation step.
         os.makedirs(os.path.join(sysroot_build_dir, "share"), exist_ok=True)
 
+        sysroot_install_path = WASILibc.sysroot_install_path(build_root, target_triple)
         shell.call([
             'make', 'install',
             '-j', str(build_jobs),
@@ -74,14 +75,22 @@ def _build(self, host_target, thread_model='single', target_triple='wasm32-wasi'
             '-C', self.source_dir,
             'OBJDIR=' + os.path.join(self.build_dir, 'obj-' + thread_model),
             'SYSROOT=' + sysroot_build_dir,
-            'INSTALL_DIR=' + WASILibc.sysroot_install_path(build_root, target_triple),
+            'INSTALL_DIR=' + sysroot_install_path,
             'CC=' + os.path.join(clang_tools_path, 'clang'),
             'AR=' + os.path.join(llvm_tools_path, 'llvm-ar'),
             'NM=' + os.path.join(llvm_tools_path, 'llvm-nm'),
             'THREAD_MODEL=' + thread_model,
             'TARGET_TRIPLE=' + target_triple,
         ])
 
+        if target_triple == "wasm32-wasi":
+            # Alias wasm32-wasip1 to wasm32-wasi as Embedded modules use
+            # wasm32-unknown-wasip1 as the target triple.
+            for subpath in ["lib", "include"]:
+                dest_path = os.path.join(sysroot_install_path, subpath, "wasm32-wasip1")
+                if not os.path.exists(dest_path):
+                    shell.symlink("wasm32-wasi", dest_path)
+
     @classmethod
     def get_dependencies(cls):
         return [llvm.LLVM]

utils/swift_build_support/swift_build_support/products/wasmstdlib.py

@@ -141,7 +141,6 @@ def _build_stdlib(self, host_target, target_triple, llvm_cmake_dir):
         self.cmake_options.define('SWIFT_STDLIB_TRACING:BOOL', 'FALSE')
         self.cmake_options.define('SWIFT_STDLIB_HAS_ASLR:BOOL', 'FALSE')
         self.cmake_options.define('SWIFT_STDLIB_CONCURRENCY_TRACING:BOOL', 'FALSE')
-        self.cmake_options.define('SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB:BOOL', 'FALSE')
         self.cmake_options.define(
             'SWIFT_STDLIB_INSTALL_PARENT_MODULE_FOR_SHIMS:BOOL', 'FALSE')
         self.cmake_options.define('SWIFT_RUNTIME_CRASH_REPORTER_CLIENT:BOOL', 'FALSE')
@@ -165,6 +164,13 @@ def _build_stdlib(self, host_target, target_triple, llvm_cmake_dir):
         self.cmake_options.define('SWIFT_ENABLE_VOLATILE:BOOL', 'TRUE')
         self.cmake_options.define('SWIFT_ENABLE_EXPERIMENTAL_OBSERVATION:BOOL', 'TRUE')
 
+        self.cmake_options.define('SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB:BOOL', 'TRUE')
+        self.cmake_options.define(
+            'SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB_CROSS_COMPILING', 'TRUE')
+        self.cmake_options.define(
+            'SWIFT_SDK_embedded_ARCH_wasm32-unknown-wasip1_PATH:PATH',
+            self._wasi_sysroot_path("wasm32-wasi"))
+
         self.add_extra_cmake_options()
 
         # Test configuration