swift - 为 Swift 添加对 32 位 Ubuntu 的支持

Question

我正在尝试在 32 位 Ubuntu 虚拟机上从源代码构建 Swift。

我做了以下修改，主要是在构建脚本中:(参见 https://pastebin.com/rmWecTu7)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 112b5d6..16db3ba 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -538,12 +538,16 @@
   endif()
 endif()

+message(STATUS ">>> CMAKE_SYSTEM_PROCESSOR: " ${CMAKE_SYSTEM_PROCESSOR})
+
 # If SWIFT_HOST_VARIANT_ARCH not given, try to detect from the CMAKE_SYSTEM_PROCESSOR.
 if(SWIFT_HOST_VARIANT_ARCH)
   set(SWIFT_HOST_VARIANT_ARCH_default, "${SWIFT_HOST_VARIANT_ARCH}")
 else()
   if("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "x86_64")
     set(SWIFT_HOST_VARIANT_ARCH_default "x86_64")
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "i686")
+    set(SWIFT_HOST_VARIANT_ARCH_default "i686")
   elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "aarch64")
     set(SWIFT_HOST_VARIANT_ARCH_default "aarch64")
   elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "ppc64")
@@ -613,10 +617,14 @@
   set(SWIFT_HOST_VARIANT "linux" CACHE STRING
       "Deployment OS for Swift host tools (the compiler) [linux].")

+  message(STATUS ">>> SWIFT_HOST_VARIANT_ARCH: " ${SWIFT_HOST_VARIANT_ARCH})
+
   # Calculate the host triple
   if("${SWIFT_HOST_TRIPLE}" STREQUAL "")
     if("${SWIFT_HOST_VARIANT_ARCH}" STREQUAL "x86_64")
       set(SWIFT_HOST_TRIPLE "x86_64-unknown-linux-gnu")
+    elseif("${SWIFT_HOST_VARIANT_ARCH}" STREQUAL "i686")
+      set(SWIFT_HOST_TRIPLE "i686-unknown-linux-gnu")
     elseif("${SWIFT_HOST_VARIANT_ARCH}" STREQUAL "aarch64")
       set(SWIFT_HOST_TRIPLE "aarch64-unknown-linux-gnu")
     elseif("${SWIFT_HOST_VARIANT_ARCH}" MATCHES "(powerpc64|powerpc64le)")
diff --git a/stdlib/public/SwiftShims/LibcShims.h b/stdlib/public/SwiftShims/LibcShims.h
index e726a62..5fd7826 100644
--- a/stdlib/public/SwiftShims/LibcShims.h
+++ b/stdlib/public/SwiftShims/LibcShims.h
@@ -33,7 +33,9 @@

 // This declaration is not universally correct.  We verify its correctness for
 // the current platform in the runtime code.
-#if defined(__linux__) && defined (__arm__)
+#if defined(__linux__) && defined(__arm__)
+typedef           int __swift_ssize_t;
+#elif defined(__linux__) && defined(__i386__)
 typedef           int __swift_ssize_t;
 #elif defined(_WIN32)
 #if defined(_M_ARM) || defined(_M_IX86)
diff --git a/utils/build-script-impl b/utils/build-script-impl
index 1bfbcc5..b058b22 100755
--- a/utils/build-script-impl
+++ b/utils/build-script-impl
@@ -449,6 +449,9 @@
                         --$(tolower "${PLAYGROUNDLOGGER_BUILD_TYPE}")
                     )
                     ;;
+                linux-i686)
+                    SWIFT_HOST_VARIANT_ARCH="i686"
+                    ;;
                 linux-armv6)
                     SWIFT_HOST_VARIANT_ARCH="armv6"
                     SWIFT_HOST_TRIPLE="armv6-unknown-linux-gnueabihf"
diff --git a/utils/swift_build_support/swift_build_support/targets.py b/utils/swift_build_support/swift_build_support/targets.py
index f4b5bb0..690a3d3 100644
--- a/utils/swift_build_support/swift_build_support/targets.py
+++ b/utils/swift_build_support/swift_build_support/targets.py
@@ -112,6 +112,7 @@
                                          is_simulator=True)

     Linux = Platform("linux", archs=[
+   "i686",
         "x86_64",
         "armv6",
         "armv7",
@@ -174,6 +175,8 @@
                 return StdlibDeploymentTarget.Linux.powerpc64le
             elif machine == 's390x':
                 return StdlibDeploymentTarget.Linux.s390x
+       elif machine == 'i686':
+       return StdlibDeploymentTarget.Linux.i686

         elif system == 'Darwin':
             if machine == 'x86_64':

尝试构建 stdlib 时构建失败，给出一些与 Float80 相关的错误:(参见 https://pastebin.com/ue8MRquU)

swift: /home/gigi/local/Source/apple/swift/lib/IRGen/StructLayout.cpp:357: void swift::irgen::StructLayoutBuilder::setAsBodyOfStruct(llvm::StructType *) const: Assertion `(!isFixedLayout() || IGM.DataLayout.getStructLayout(type)->getSizeInBytes() == CurSize.getValue()) && "LLVM size of fixed struct type does not match StructLayout size"' failed.
/home/gigi/local/Source/apple/build/Ninja-ReleaseAssert/swift-linux-i686/bin/swift[0xc335ea0]
Stack dump:
0.  Program arguments: /home/gigi/local/Source/apple/build/Ninja-ReleaseAssert/swift-linux-i686/bin/swift -frontend -c -filelist /tmp/sources-628097 -disable-objc-attr-requires-foundation-module -target i686-unknown-linux-gnu -disable-objc-interop -sdk / -I /home/gigi/local/Source/apple/build/Ninja-ReleaseAssert/swift-linux-i686/./lib/swift/linux/i686 -warn-swift3-objc-inference-complete -module-cache-path /home/gigi/local/Source/apple/build/Ninja-ReleaseAssert/swift-linux-i686/./module-cache -module-link-name swiftCore -nostdimport -parse-stdlib -resource-dir /home/gigi/local/Source/apple/build/Ninja-ReleaseAssert/swift-linux-i686/./lib/swift -swift-version 3 -O -D INTERNAL_CHECKS_ENABLED -group-info-path /home/gigi/local/Source/apple/swift/stdlib/public/core/GroupInfo.json -enable-sil-ownership -Xllvm -sil-inline-generics -Xllvm -sil-partial-specialization -Xcc -D__SWIFT_CURRENT_DYLIB=swiftCore -parse-as-library -module-name Swift -o /home/gigi/local/Source/apple/build/Ninja-ReleaseAssert/swift-linux-i686/stdlib/public/core/linux/i686/Swift.o 
1.  While running pass #147 SILFunctionTransform "SIL alloc_stack Hoisting" on SILFunction "@_T0s7Float80V15_representationAB01_A14RepresentationVvg".
 for getter for _representation at /home/gigi/local/Source/apple/swift/stdlib/public/core/FloatingPointTypes.swift.gyb:342:16
2.  While converting type 'Float80' (declared at [/home/gigi/local/Source/apple/swift/stdlib/public/core/FloatingPointTypes.swift.gyb:74:8 - line:3662:1] RangeText="struct Float80 {
  public // @testable
  var _value: Builtin.FPIEEE80

  /// Creates a value initialized to zero.
  @_inlineable // FIXME(sil-serialize-all)
  @_transparent
  public init() {
    let zero: Int64 = 0
    self._value = Builtin.sitofp_Int64_FPIEEE80(zero._value)
  }

  @_inlineable // FIXME(sil-serialize-all)
  @_transparent
  public // @testable
  init(_bits v: Builtin.FPIEEE80) {
    self._value = v
  }
}")
<unknown>:0: error: unable to execute command: Aborted
<unknown>:0: error: compile command failed due to signal 6 (use -v to see invocation)
ninja: build stopped: subcommand failed.
/home/gigi/local/Source/apple/swift/utils/build-script: fatal error: command terminated with a non-zero exit status 1, aborting
gigi@gigi-VirtualBox:~$ ]

使用 ~/local/Source/apple/swift/utils/build-script --release 进行构建。

我猜错误与此修改有关:

#elif defined(__linux__) && defined(__i386__)
typedef           int __swift_ssize_t;

Answer 1

Swift 官方项目还不支持 32 位架构。有官方票:Port Swift to Linux x86 32-bit
如果您想自己添加此端口，您将有更多机会获得此票证的支持。