[Stdlib][Build] Fix the standard library build for fully static Linux.

lib/Basic/Platform.cpp

@@ -231,7 +231,17 @@ StringRef swift::getPlatformNameForTriple(const llvm::Triple &triple) {
   case llvm::Triple::XROS:
     return getPlatformNameForDarwin(getDarwinPlatformKind(triple));
   case llvm::Triple::Linux:
-    return triple.isAndroid() ? "android" : "linux";
+    if (triple.isAndroid())
+      return "android";
+    else if (triple.isMusl()) {
+      // The triple for linux-static is <arch>-swift-linux-musl, to distinguish
+      // it from a "normal" musl set-up (ala Alpine).
+      if (triple.getVendor() == llvm::Triple::Swift)
+        return "linux-static";
+      else
+        return "musl";
+    } else
+      return "linux";
   case llvm::Triple::FreeBSD:
     return "freebsd";
   case llvm::Triple::OpenBSD:

lib/ClangImporter/ClangImporter.cpp

@@ -646,7 +646,7 @@ void importer::getNormalInvocationArguments(
     // using Glibc or a libc that respects that flag. This will cause some
     // source breakage however (specifically with strerror_r()) on Linux
     // without a workaround.
-    if (triple.isOSFuchsia() || triple.isAndroid()) {
+    if (triple.isOSFuchsia() || triple.isAndroid() || triple.isMusl()) {
       // Many of the modern libc features are hidden behind feature macros like
       // _GNU_SOURCE or _XOPEN_SOURCE.
       invocationArgStrs.insert(invocationArgStrs.end(), {

lib/ClangImporter/ClangIncludePaths.cpp

@@ -180,7 +180,7 @@ createClangArgs(const ASTContext &ctx, clang::driver::Driver &clangDriver) {
 
 static bool shouldInjectLibcModulemap(const llvm::Triple &triple) {
   return triple.isOSGlibc() || triple.isOSOpenBSD() || triple.isOSFreeBSD() ||
-         triple.isAndroid() || triple.isOSWASI();
+         triple.isAndroid() || triple.isMusl() || triple.isOSWASI();
 }
 
 static SmallVector<std::pair<std::string, std::string>, 2>
@@ -254,8 +254,9 @@ static void getLibStdCxxFileMapping(
   // We currently only need this when building for Linux.
   if (!triple.isOSLinux())
     return;
-  // Android uses libc++.
-  if (triple.isAndroid())
+  // Android uses libc++, as does our fully static Linux config.
+  if (triple.isAndroid()
+      || (triple.isMusl() && triple.getVendor() == llvm::Triple::Swift))
     return;
 
   // Extract the libstdc++ installation path from Clang driver.
@@ -529,30 +530,44 @@ ClangInvocationFileMapping swift::getClangInvocationFileMapping(
 
   const llvm::Triple &triple = ctx.LangOpts.Target;
 
+  // For modulemaps that have all the C standard library headers together in
+  // a single module, we end up with module cycles with the clang _Builtin_
+  // modules.  e.g. <inttypes.h> includes <stdint.h> on these platforms. The
+  // clang builtin <stdint.h> include-nexts <stdint.h>. When both of those
+  // platform headers are in the SwiftLibc module, there's a module cycle
+  // SwiftLibc -> _Builtin_stdint -> SwiftLibc (i.e. inttypes.h (platform) ->
+  // stdint.h (builtin) -> stdint.h (platform)).
+  //
+  // Until these modulemaps can be fixed, the builtin headers need to join
+  // the system modules to avoid the cycle.
+  //
+  // Note that this does nothing to fix the same problem with C++ headers,
+  // and that this is generally a fragile solution.
+  //
+  // We start by assuming we do *not* need to do this, then enable it for
+  // affected modulemaps.
+  result.requiresBuiltinHeadersInSystemModules = false;
+
   SmallVector<std::pair<std::string, std::string>, 2> libcFileMapping;
   if (triple.isOSWASI()) {
     // WASI Mappings
     libcFileMapping =
         getLibcFileMapping(ctx, "wasi-libc.modulemap", std::nullopt, vfs);
+
+    // WASI's module map needs fixing
+    result.requiresBuiltinHeadersInSystemModules = true;
+  } else if (triple.isMusl()) {
+    libcFileMapping =
+        getLibcFileMapping(ctx, "musl.modulemap", StringRef("SwiftMusl.h"), vfs);
   } else {
     // Android/BSD/Linux Mappings
     libcFileMapping = getLibcFileMapping(ctx, "glibc.modulemap",
                                          StringRef("SwiftGlibc.h"), vfs);
+
+    // glibc.modulemap needs fixing
+    result.requiresBuiltinHeadersInSystemModules = true;
   }
   result.redirectedFiles.append(libcFileMapping);
-  // Both libc module maps have the C standard library headers all together in a
-  // SwiftLibc module. That leads to module cycles with the clang _Builtin_
-  // modules. e.g. <inttypes.h> includes <stdint.h> on these platforms. The
-  // clang builtin <stdint.h> include-nexts <stdint.h>. When both of those
-  // platform headers are in the SwiftLibc module, there's a module cycle
-  // SwiftLibc -> _Builtin_stdint -> SwiftLibc (i.e. inttypes.h (platform) ->
-  // stdint.h (builtin) -> stdint.h (platform)). Until this can be fixed in
-  // these module maps, the clang builtin headers need to join the "system"
-  // modules (SwiftLibc). i.e. when the clang builtin stdint.h is in the
-  // SwiftLibc module too, the cycle goes away. Note that
-  // -fbuiltin-headers-in-system-modules does nothing to fix the same problem
-  // with C++ headers, and is generally fragile.
-  result.requiresBuiltinHeadersInSystemModules = !libcFileMapping.empty();
 
   if (ctx.LangOpts.EnableCXXInterop)
     getLibStdCxxFileMapping(result, ctx, vfs);

lib/Driver/UnixToolChains.cpp

@@ -127,7 +127,9 @@ bool isAmazonLinux2023Host() {
     }
 
 std::string toolchains::GenericUnix::getDefaultLinker() const {
-  if (getTriple().isAndroid() || isAmazonLinux2023Host())
+  if (getTriple().isAndroid() || isAmazonLinux2023Host()
+      || (getTriple().isMusl()
+          && getTriple().getVendor() == llvm::Triple::Swift))
     return "lld";
 
   switch (getTriple().getArch()) {
@@ -285,7 +287,8 @@ toolchains::GenericUnix::constructInvocation(const DynamicLinkJobAction &job,
   }
 
   SmallString<128> SharedResourceDirPath;
-  getResourceDirPath(SharedResourceDirPath, context.Args, /*Shared=*/true);
+  getResourceDirPath(SharedResourceDirPath, context.Args,
+                     /*Shared=*/!(staticExecutable || staticStdlib));
 
   SmallString<128> swiftrtPath = SharedResourceDirPath;
   llvm::sys::path::append(swiftrtPath,

stdlib/private/SwiftPrivate/CMakeLists.txt

@@ -28,6 +28,7 @@ add_swift_target_library(swiftSwiftPrivate ${SWIFT_STDLIB_LIBRARY_BUILD_TYPES} I
   SWIFT_MODULE_DEPENDS_MACCATALYST ${swift_swiftprivate_darwin_depencencies}
   SWIFT_MODULE_DEPENDS_FREESTANDING "${SWIFT_FREESTANDING_TEST_DEPENDENCIES}"
   SWIFT_MODULE_DEPENDS_LINUX Glibc
+  SWIFT_MODULE_DEPENDS_LINUX_STATIC Musl
   SWIFT_MODULE_DEPENDS_FREEBSD Glibc
   SWIFT_MODULE_DEPENDS_OPENBSD Glibc
   SWIFT_MODULE_DEPENDS_CYGWIN Glibc

stdlib/private/SwiftPrivateLibcExtras/CMakeLists.txt

@@ -39,6 +39,7 @@ add_swift_target_library(swiftSwiftPrivateLibcExtras ${SWIFT_STDLIB_LIBRARY_BUIL
   SWIFT_MODULE_DEPENDS_MACCATALYST ${swift_private_libc_extras_darwin_depencencies}
   SWIFT_MODULE_DEPENDS_FREESTANDING "${SWIFT_FREESTANDING_TEST_DEPENDENCIES}"
   SWIFT_MODULE_DEPENDS_LINUX Glibc
+  SWIFT_MODULE_DEPENDS_LINUX_STATIC Musl
   SWIFT_MODULE_DEPENDS_FREEBSD Glibc
   SWIFT_MODULE_DEPENDS_OPENBSD Glibc
   SWIFT_MODULE_DEPENDS_CYGWIN Glibc

stdlib/private/SwiftPrivateThreadExtras/CMakeLists.txt

@@ -20,6 +20,7 @@ add_swift_target_library(swiftSwiftPrivateThreadExtras ${SWIFT_STDLIB_LIBRARY_BU
   SWIFT_MODULE_DEPENDS_MACCATALYST ${swift_private_thread_extras_darwin_depencencies}
   SWIFT_MODULE_DEPENDS_FREESTANDING "${SWIFT_FREESTANDING_TEST_DEPENDENCIES}"
   SWIFT_MODULE_DEPENDS_LINUX Glibc
+  SWIFT_MODULE_DEPENDS_LINUX_STATIC Musl
   SWIFT_MODULE_DEPENDS_FREEBSD Glibc
   SWIFT_MODULE_DEPENDS_OPENBSD Glibc
   SWIFT_MODULE_DEPENDS_CYGWIN Glibc

stdlib/private/SwiftReflectionTest/CMakeLists.txt

@@ -15,13 +15,20 @@ if (SWIFT_INCLUDE_TESTS AND SWIFT_BUILD_DYNAMIC_STDLIB)
     SWIFT_MODULE_DEPENDS_WATCHOS ${swift_reflection_test_darwin_depencencies}
     SWIFT_MODULE_DEPENDS_XROS ${swift_reflection_test_darwin_depencencies}
     SWIFT_MODULE_DEPENDS_LINUX Glibc
+    SWIFT_MODULE_DEPENDS_LINUX_STATIC Musl
     SWIFT_MODULE_DEPENDS_FREEBSD Glibc
     SWIFT_MODULE_DEPENDS_OPENBSD Glibc
     SWIFT_MODULE_DEPENDS_WINDOWS CRT
     INSTALL_IN_COMPONENT stdlib-experimental
-    DARWIN_INSTALL_NAME_DIR "${SWIFT_DARWIN_STDLIB_PRIVATE_INSTALL_NAME_DIR}")
+    DARWIN_INSTALL_NAME_DIR "${SWIFT_DARWIN_STDLIB_PRIVATE_INSTALL_NAME_DIR}"
+
+    TARGET_SDKS NOT LINUX_STATIC)
 
   foreach(SDK ${SWIFT_SDKS})
+    if ("${SDK}" STREQUAL "LINUX_STATIC")
+      continue()
+    endif()
+
     foreach(ARCH ${SWIFT_SDK_${SDK}_ARCHITECTURES})
       set(VARIANT_SUFFIX "-${SWIFT_SDK_${SDK}_LIB_SUBDIR}-${ARCH}")
       add_dependencies("swiftSwiftReflectionTest${VARIANT_SUFFIX}"

stdlib/public/Backtracing/CMakeLists.txt

@@ -92,5 +92,5 @@ add_swift_target_library(swift_Backtracing ${SWIFT_STDLIB_LIBRARY_BUILD_TYPES} I
   INSTALL_IN_COMPONENT stdlib
   MACCATALYST_BUILD_FLAVOR "zippered"
 
-  TARGET_SDKS OSX LINUX
+  TARGET_SDKS OSX LINUX LINUX_STATIC
 )

stdlib/public/Backtracing/Context.swift

@@ -708,10 +708,10 @@ extension arm_gprs {
           }
         }
 
-	to[31] = mctx.sp
+	to[31] = UInt64(mctx.sp)
       }
     }
-    gprs.pc = mctx.pc
+    gprs.pc = UInt64(mctx.pc)
     gprs.valid = 0x1ffffffff
   }
 

stdlib/public/Cxx/cxxshim/CMakeLists.txt

@@ -5,7 +5,7 @@ foreach(sdk ${SWIFT_SDKS})
 
   add_custom_command(OUTPUT ${module_dir}
                      COMMAND ${CMAKE_COMMAND} "-E" "make_directory" "${module_dir}")
-  if(SWIFT_BUILD_STATIC_STDLIB)
+  if(SWIFT_BUILD_STATIC_STDLIB OR SWIFT_SDK_${sdk}_STATIC_ONLY)
     add_custom_command(OUTPUT ${module_dir_static}
                        COMMAND ${CMAKE_COMMAND} "-E" "make_directory" "${module_dir_static}")
   endif()
@@ -18,7 +18,7 @@ foreach(sdk ${SWIFT_SDKS})
                        COMMENT "Copying ${source} to ${module_dir}")
     list(APPEND outputs "${module_dir}/${source}")
 
-    if(SWIFT_BUILD_STATIC_STDLIB)
+    if(SWIFT_BUILD_STATIC_STDLIB OR SWIFT_SDK_${sdk}_STATIC_ONLY)
       add_custom_command(OUTPUT ${module_dir_static}/${source}
                          DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${source}
                          COMMAND ${CMAKE_COMMAND} "-E" "copy_if_different" "${CMAKE_CURRENT_SOURCE_DIR}/${source}" "${module_dir_static}/${source}"
@@ -27,7 +27,7 @@ foreach(sdk ${SWIFT_SDKS})
     endif()
   endforeach()
   list(APPEND outputs ${module_dir})
-  if(SWIFT_BUILD_STATIC_STDLIB)
+  if(SWIFT_BUILD_STATIC_STDLIB OR SWIFT_SDK_${sdk}_STATIC_ONLY)
     list(APPEND outputs ${module_dir_static})
   endif()
 
@@ -40,7 +40,7 @@ foreach(sdk ${SWIFT_SDKS})
   swift_install_in_component(FILES libcxxshim.modulemap libcxxshim.h libcxxstdlibshim.h
                              DESTINATION "lib/swift/${SWIFT_SDK_${sdk}_LIB_SUBDIR}"
                              COMPONENT compiler)
-  if(SWIFT_BUILD_STATIC_STDLIB)
+  if(SWIFT_BUILD_STATIC_STDLIB OR SWIFT_SDK_${sdk}_STATIC_ONLY)
     swift_install_in_component(FILES libcxxshim.modulemap libcxxshim.h libcxxstdlibshim.h
                                DESTINATION "lib/swift_static/${SWIFT_SDK_${sdk}_LIB_SUBDIR}"
                                COMPONENT compiler)

stdlib/public/Cxx/libstdcxx/CMakeLists.txt

@@ -38,7 +38,7 @@ foreach(sdk ${SWIFT_SDKS})
   list(APPEND libstdcxx_modulemap_target_list ${copy_libstdcxx_header})
   add_dependencies(swift-stdlib-${SWIFT_SDK_${sdk}_LIB_SUBDIR} ${copy_libstdcxx_header})
 
-  if(SWIFT_BUILD_STATIC_STDLIB)
+  if(SWIFT_BUILD_STATIC_STDLIB OR SWIFT_SDK_${sdk}_STATIC_ONLY)
     add_custom_command_target(
         copy_libstdcxx_modulemap_static
         COMMAND
@@ -73,7 +73,7 @@ foreach(sdk ${SWIFT_SDKS})
       DESTINATION "lib/swift/${SWIFT_SDK_${sdk}_LIB_SUBDIR}"
       COMPONENT sdk-overlay)
 
-  if(SWIFT_BUILD_STATIC_STDLIB)
+  if(SWIFT_BUILD_STATIC_STDLIB OR SWIFT_SDK_${sdk}_STATIC_ONLY)
     swift_install_in_component(FILES "${libstdcxx_modulemap_out_static}"
         DESTINATION "lib/swift_static/${SWIFT_SDK_${sdk}_LIB_SUBDIR}"
         COMPONENT sdk-overlay)

stdlib/public/Differentiation/CMakeLists.txt

@@ -43,6 +43,7 @@ add_swift_target_library(swift_Differentiation ${SWIFT_STDLIB_LIBRARY_BUILD_TYPE
   SWIFT_MODULE_DEPENDS_WATCHOS ${swiftDifferentiationDarwinDependencies}
   SWIFT_MODULE_DEPENDS_XROS ${swiftDifferentiationDarwinDependencies}
   SWIFT_MODULE_DEPENDS_LINUX Glibc
+  SWIFT_MODULE_DEPENDS_LINUX_STATIC Musl
   SWIFT_MODULE_DEPENDS_FREEBSD Glibc
   SWIFT_MODULE_DEPENDS_OPENBSD Glibc
   SWIFT_MODULE_DEPENDS_CYGWIN Glibc

stdlib/public/SwiftRemoteMirror/CMakeLists.txt

@@ -16,4 +16,6 @@ add_swift_target_library(swiftRemoteMirror
                          SWIFT_COMPILE_FLAGS ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
                          DARWIN_INSTALL_NAME_DIR "${SWIFTLIB_DARWIN_INSTALL_NAME_DIR}"
                          INSTALL_IN_COMPONENT
-                           swift-remote-mirror)
+                           swift-remote-mirror
+
+                         TARGET_SDKS NOT LINUX_STATIC)

stdlib/public/SwiftShims/swift/shims/CMakeLists.txt

@@ -34,11 +34,9 @@ add_custom_command(
     OUTPUT "${output_dir}"
     COMMAND ${CMAKE_COMMAND} "-E" "make_directory" "${output_dir}")
 
-if(SWIFT_BUILD_STATIC_STDLIB)
-  add_custom_command(
-      OUTPUT "${output_dir_static}"
-      COMMAND ${CMAKE_COMMAND} "-E" "make_directory" "${output_dir_static}")
-endif()
+add_custom_command(
+    OUTPUT "${output_dir_static}"
+    COMMAND ${CMAKE_COMMAND} "-E" "make_directory" "${output_dir_static}")
 
 set(outputs)
 foreach(input ${sources})
@@ -52,17 +50,15 @@ foreach(input ${sources})
       COMMENT "Copying ${input} to ${output_dir}")
   list(APPEND outputs "${output_dir}/${input}")
 
-  if(SWIFT_BUILD_STATIC_STDLIB)
-    add_custom_command(
-        OUTPUT "${output_dir_static}/${input}"
-        DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/${input}"
-        COMMAND
-          "${CMAKE_COMMAND}" "-E" "copy_if_different"
-          "${CMAKE_CURRENT_SOURCE_DIR}/${input}"
-          "${output_dir_static}/${input}"
-        COMMENT "Copying ${input} to ${output_dir_static}")
-    list(APPEND outputs "${output_dir_static}/${input}")
-  endif()
+  add_custom_command(
+    OUTPUT "${output_dir_static}/${input}"
+    DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/${input}"
+    COMMAND
+      "${CMAKE_COMMAND}" "-E" "copy_if_different"
+      "${CMAKE_CURRENT_SOURCE_DIR}/${input}"
+      "${output_dir_static}/${input}"
+    COMMENT "Copying ${input} to ${output_dir_static}")
+  list(APPEND outputs "${output_dir_static}/${input}")
 endforeach()
 if (SWIFT_STDLIB_INSTALL_PARENT_MODULE_FOR_SHIMS)
   # Copy the module map into the parent directory. Using "parent.modulemap"
@@ -143,21 +139,19 @@ add_custom_command_target(unused_var
 
 add_dependencies(copy_shim_headers symlink_clang_headers)
 
-if(SWIFT_BUILD_STATIC_STDLIB)
-  add_custom_command_target(unused_var
-      COMMAND
-        "${CMAKE_COMMAND}" "-E" "make_directory" "${SWIFTSTATICLIB_DIR}"
-      COMMAND
-        "${CMAKE_COMMAND}" "-E" "${SWIFT_COPY_OR_SYMLINK_DIR}"
-        "${clang_headers_location}"
-        "${SWIFTSTATICLIB_DIR}/clang"
+add_custom_command_target(unused_var
+  COMMAND
+    "${CMAKE_COMMAND}" "-E" "make_directory" "${SWIFTSTATICLIB_DIR}"
+  COMMAND
+    "${CMAKE_COMMAND}" "-E" "${SWIFT_COPY_OR_SYMLINK_DIR}"
+    "${clang_headers_location}"
+    "${SWIFTSTATICLIB_DIR}/clang"
 
-      CUSTOM_TARGET_NAME "symlink_clang_headers_static"
-      OUTPUT "${SWIFTSTATICLIB_DIR}/clang"
-      COMMENT "Symlinking Clang resource headers into ${SWIFTSTATICLIB_DIR}/clang")
+  CUSTOM_TARGET_NAME "symlink_clang_headers_static"
+  OUTPUT "${SWIFTSTATICLIB_DIR}/clang"
+  COMMENT "Symlinking Clang resource headers into ${SWIFTSTATICLIB_DIR}/clang")
 
-      add_dependencies(copy_shim_headers symlink_clang_headers_static)
-endif()
+add_dependencies(copy_shim_headers symlink_clang_headers_static)
 
 if(NOT SWIFT_BUILT_STANDALONE)
   if(TARGET clang-resource-headers) # LLVM > 8
@@ -227,15 +221,15 @@ if (SWIFT_STDLIB_INSTALL_PARENT_MODULE_FOR_SHIMS)
                              COMPONENT stdlib)
 endif()
 
-if(SWIFT_BUILD_STATIC_STDLIB)
-  swift_install_in_component(FILES ${sources}
-                             DESTINATION "lib/swift_static/shims"
+if (SWIFT_BUILD_STATIC_STDLIB)
+swift_install_in_component(FILES ${sources}
+                           DESTINATION "lib/swift_static/shims"
+                           COMPONENT stdlib)
+if (SWIFT_STDLIB_INSTALL_PARENT_MODULE_FOR_SHIMS)
+  swift_install_in_component(FILES "${output_dir_static}/../module.modulemap"
+                             DESTINATION "lib/swift_static"
                              COMPONENT stdlib)
-  if (SWIFT_STDLIB_INSTALL_PARENT_MODULE_FOR_SHIMS)
-    swift_install_in_component(FILES "${output_dir_static}/../module.modulemap"
-                               DESTINATION "lib/swift_static"
-                               COMPONENT stdlib)
-  endif()
+endif()
 endif()
 
 # Install Clang headers under the Swift library so that an installed Swift's
@@ -245,12 +239,10 @@ swift_install_in_component(DIRECTORY "${clang_headers_location}/"
                            COMPONENT clang-builtin-headers
                            PATTERN "*.h")
 
-if(SWIFT_BUILD_STATIC_STDLIB)
-  swift_install_in_component(DIRECTORY "${clang_headers_location}/"
-                             DESTINATION "lib/swift_static/clang"
-                             COMPONENT clang-builtin-headers
-                             PATTERN "*.h")
-endif()
+swift_install_in_component(DIRECTORY "${clang_headers_location}/"
+  DESTINATION "lib/swift_static/clang"
+  COMPONENT clang-builtin-headers
+  PATTERN "*.h")
 
 if(SWIFT_BUILD_RUNTIME_WITH_HOST_COMPILER OR SWIFT_PREBUILT_CLANG)
   # This will still link against the Swift-forked clang headers if the Swift
@@ -268,12 +260,10 @@ swift_install_symlink_component(clang-resource-dir-symlink
   TARGET ${SWIFT_CLANG_RESOURCE_DIR_SYMLINK_INSTALL_TARGET}
   DESTINATION "lib/swift")
 
-if(SWIFT_BUILD_STATIC_STDLIB)
-  swift_install_symlink_component(clang-resource-dir-symlink
-    LINK_NAME clang
-    TARGET ${SWIFT_CLANG_RESOURCE_DIR_SYMLINK_INSTALL_TARGET}
-    DESTINATION "lib/swift_static")
-endif()
+swift_install_symlink_component(clang-resource-dir-symlink
+  LINK_NAME clang
+  TARGET ${SWIFT_CLANG_RESOURCE_DIR_SYMLINK_INSTALL_TARGET}
+  DESTINATION "lib/swift_static")
 
 # Possibly install Clang headers under Clang's resource directory in case we
 # need to use a different version of the headers than the installed Clang. This