utils/swift-project-settings.el - third_party/swift - Git at Google

 ;===--- swift-project-settings.el - Swift project's format conventions ---===;
 ;
 ; This source file is part of the Swift.org open source project
 ;
 ; Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
 ; Licensed under Apache License v2.0 with Runtime Library Exception
 ;
 ; See https://swift.org/LICENSE.txt for license information
 ; See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 ;
 ;===----------------------------------------------------------------------===;
 ;
 ;  Emacs-lisp support for automatically formatting things according to this
 ;  project's conventions.  To prevent this file from being automatically
 ;  loaded, add (provide 'swift-project-settings) to your .emacs
 ;
 ;===----------------------------------------------------------------------===;


 ;; Associate .swift files with swift-mode
 (setq auto-mode-alist
    (append '(("\\.swift$" . swift-mode) ("\\.gyb$" python-mode t)) auto-mode-alist))

 ;; Make sure we know where to find swift-mode
 (autoload 'swift-mode (concat (file-name-directory load-file-name) "swift-mode")
   "Major mode for editing SWIFT source files.
   \\{swift-mode-map}
   Runs swift-mode-hook on startup."
   :interactive
   )

 (require 'cc-styles)

 ;; This style is appropriate for indenting Swift's C++ source
 (c-add-style "swift"
              '((c-basic-offset . 2)
                (c-offsets-alist
                 (namespace-open . 0)
                 (template-args-cont c-lineup-template-args +)
                 (knr-argdecl-intro . +)
                 (substatement-open . +)
                 (substatement-label . 2)
                 (label . 2)
                 (inline-open . +)
                 (inexpr-class . +)
                 (defun-open . 0)
                 (func-decl-cont . +)
                 (knr-argdecl . 0)
                 (topmost-intro-cont . c-lineup-topmost-intro-cont)
                 (annotation-top-cont . 0)
                 (annotation-var-cont . +)
                 (member-init-cont . c-lineup-multi-inher)
                 (block-open . 0)
                 (brace-list-open . 0)
                 (brace-entry-open . 0)
                 (statement-case-open . 0)
                 (do-while-closure . 0)
                 (catch-clause . 0)
                 (stream-op . c-lineup-streamop)
                 (cpp-macro-cont . +)
                 (friend . 0)
                 (objc-method-intro .
                                    [0])
                 (objc-method-args-cont . c-lineup-ObjC-method-args)
                 (objc-method-call-cont c-lineup-ObjC-method-call-colons c-lineup-ObjC-method-call +)
                 (extern-lang-open . 0)
                 (module-open . 0)
                 (composition-open . 0)
                 (extern-lang-close . 0)
                 (module-close . 0)
                 (composition-close . 0)
                 (inextern-lang . +)
                 (inmodule . +)
                 (incomposition . +)
                 (inlambda . c-lineup-inexpr-block)
                 (lambda-intro-cont . +)
                 (inexpr-statement . +)
                 (topmost-intro . 0)
                 (defun-block-intro . +)
                 (statement . 0)
                 (defun-close . 0)
                 (statement-cont . +)
                 (brace-list-intro . +)
                 (brace-list-entry . 0)
                 (brace-list-close . 0)
                 (statement-block-intro . +)
                 (block-close . 0)
                 (innamespace . 0)
                 (inher-intro . +)
                 (class-open . 0)
                 (inclass . +)
                 (access-label . 0)
                 (member-init-intro . +)
                 (substatement . +)
                 (inline-close . 0)
                 (class-close . 0)
                 (namespace-close . 0)
                 (case-label . 0)
                 (statement-case-intro . +)
                 (cpp-define-intro . +)
                 (else-clause . 0)
                 (arglist-intro . +)
                 (arglist-cont . 0)
                 (c . c-lineup-C-comments)
                 (inher-cont . c-lineup-multi-inher)
                 (string . -1000)
                 (comment-intro . c-lineup-comment)
                 (arglist-cont-nonempty . c-lineup-arglist)
                 (arglist-close . c-lineup-close-paren)
                 (cpp-macro . -1000))))

 ;; When this file is loaded in response to visiting a file in the
 ;; project, it won't have had its major mode set up according to the
 ;; project settings yet.  For example, Swift files may come up in
 ;; Fundamental mode, and C++ files won't use the swift style, unless
 ;; we do something.  This hack causes the file to be re-mode-ed.
 (unless (eq major-mode 'dired-mode) (set-auto-mode))

 (defun swift-project-comment-end ()
   "If comment-end is non-empty returns it, stripped of leading whitespace.  Returns nil otherwise"
   (replace-regexp-in-string
    "\\` +" ""
    (if (and comment-end (> (length comment-end) 0)) comment-end v1)))

 (define-skeleton swift-header
   "Insert the Swift header at the top of a file

 Note: this skeleton presently assumes that comment-start creates
 a comment until end-of-line.  Handling paired comment syntax is
 possible, but more work, and someone needs to decide what such an
 Swift header should look like.
 "
   ;; prompt
   "Short description (RET for none): "

   ;; v1 is comment-start without trailing whitespace.  Presumably
   ;; nobody is crazy enough to define a language where whitespace
   ;; determines whether something is a comment, but c++ mode and
   ;; friends have a space at the end of comment-start, which messes up
   ;; the Swift header format.
   ;;
   ;; When there's no comment syntax defined, we use "//"; precedent is
   ;; in the project's README file.
   '(setq v1 (replace-regexp-in-string " +\\'" "" (or comment-start "//")))

   ;; v2 is the name of the file
   '(setq v2 (file-name-nondirectory (buffer-file-name)))
   v1 "===--- " v2
   ;; if the short description is empty, eat up the preceding " - "
   " - " str | -3
   " "
   ;; v3 is t if there was a short description
   '(setq v3 (> (length str) 0))

   '(setq v4 (or (swift-project-comment-end) v1))

   ;; Generate dashes to fill out the rest of the top line
   (make-string (max (- 65 (+ (if v3 (+ 3 (length str)) 0) (length v2))) 3) ?-)
   "===" v4 "\n"

     ;; Use whatever comment character is usual for the current mode in place of "//"
   (replace-regexp-in-string
    "//$" v4
    (replace-regexp-in-string "^//" v1
 "//
 // This source file is part of the Swift.org open source project
 //
 // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 //
 //===----------------------------------------------------------------------===//
 "))
   ;; if there was a short description, add a section for a longer
   ;; description and leave the cursor there
   (when v3
     (replace-regexp-in-string
      "//$" v4
      (replace-regexp-in-string "^//" v1
 "//
 //  ")))
   (when v3 '_)
   (when v3
     (replace-regexp-in-string
      "//$" v4
      (replace-regexp-in-string "^//" v1 "
 //
 //===----------------------------------------------------------------------===//
 ")
     )))

 (define-skeleton swift-divider
   "Insert a Swift //===--- ... ---===// divider
 "
   ;; prompt
   "Text (RET for none): "

   ;; v1 is comment-start without trailing whitespace.  Presumably
   ;; nobody is crazy enough to define a language where whitespace
   ;; determines whether something is a comment, but c++ mode and
   ;; friends have a space at the end of comment-start, which messes up
   ;; the Swift header format.
   ;;
   ;; When there's no comment syntax defined, we use "//"; precedent is
   ;; in the project's README file.
   '(setq v1 (replace-regexp-in-string " +\\'" "" (or comment-start "//")))

   '(setq v2 (or (swift-project-comment-end) v1))

   v1 "===--- "
   str & " " | -1
   '(setq v3 (length str))

   ;; Generate dashes to fill out the rest of the top line
   (make-string
    (max 3
         (- 77 (current-column) (length v2)))
    ?-)

   "===" v2
 )

 (defvar swift-project-auto-insert-alist
   ;; Currently we match any file and insert the Swift header.  We can
   ;; make the regexp more specific or filter based on mode if this
   ;; doesn't work out.
   '((("" . "Swift header") . swift-header))
   "auto-insert-alist entries that are just for the Swift project"
   )

 (defadvice auto-insert (around swift-project-auto-insert activate)
   "Modify auto-insert so that swift-project-auto-insert-alist
 takes precedence for files in the Swift project"
   ;; Assume that files with c-file-style set to "swift" are
   ;; part of the Swift project.  Because it's set in
   ;; .dir-locals.el, this will apply to all files, not just
   ;; those using cc-mode
   (if (and (boundp 'c-file-style) (equal c-file-style "swift"))
       (let ((auto-insert-alist
              (append swift-project-auto-insert-alist auto-insert-alist))
             ;; The default is to ask when creating a new file.  Inside
             ;; this project, we always want the Swift header, so only
             ;; prompt if the user has set auto-insert to /always/
             ;; prompt.
             (auto-insert-query (if (eq auto-insert-query 'function) nil auto-insert-query)))
         ad-do-it)
     ad-do-it))

 (require 'compile) ;; for compilation-error-regexp-alist et al.
 (push 'swift-stdlibunittest-possibly-expected-assertion compilation-error-regexp-alist)
 (push `(swift-stdlibunittest-possibly-expected-assertion "^\\(\\(?:stdout\\|stderr\\)>>> *\\)?.*\\(?:failed\\(?: at\\|.*file\\)\\|.*: file\\) \\([^,]*\\), line \\([0-9]+\\)$"
               2 3 ,(not :column) 0)
       compilation-error-regexp-alist-alist)

 (push 'swift-stdlibunittest-stackframe compilation-error-regexp-alist)
 (push `(swift-stdlibunittest-stackframe "^\\(?:\\(?:stdout\\|stderr\\)>>> *\\)?#[0-9]+: \\(.+\\):\\([0-9]+\\)\\(?: +.*\\)?$"
               1 2 ,(not :column) ,(not :just-a-warning))
       compilation-error-regexp-alist-alist)

 (push 'swift-stdlibunittest-failure compilation-error-regexp-alist)
 (push `(swift-stdlibunittest-failure "^\\(?:\\(?:stdout\\|stderr\\)>>> *\\)?check failed at \\(.*?\\), line \\([0-9]+\\)$"
               1 2 ,(not :column) ,(not :just-a-warning))
       compilation-error-regexp-alist-alist)

 (defvar swift-project-directory
   (file-name-directory (directory-file-name (file-name-directory load-file-name)))
   "Directory where the swift project containing this file is located.
 Defaults to the parent directory of `swift-project-settings.el'.
 The setting for file-local values of this variable comes from
 .dir-locals.el in the project's root directory")
 (put 'swift-project-directory 'safe-local-variable 'stringp)

 (defun swift-project-default-build-directory (project-directory)
   "Returns the default build directory given a project directory name, `DIR/../build'"
   (concat (file-name-directory (directory-file-name project-directory)) "build/"))

 ;; This name doesn't end in "function" to avoid being unconditionally marked as risky.
 (defcustom swift-project-build-directory-fn 'swift-project-default-build-directory
   "A function that, given a swift project directory name,
 computes the directory where your build leaves build products.
 Flymake support may search here for a swift compiler to use, for example.
 Defaults to `(concat swift-project-directory \"../build\")'."
   :type 'function
 )

 (defun swift-project-executable-find (command)
   "Find the newest executable with the given name in the utils/ directory or in any build directory, falling back to the exec-path as a last resort.
 Given an absolute path, returns it verbatim.  This is a pretty
 good heuristic for locating things to use when working on swift
 itself, and is used as the value of swift-find-executable-fn"
   (if (file-name-absolute-p command) command
     (let* ((utility (concat swift-project-directory "utils/" command))
            (newest (and (file-executable-p utility) utility)))
       (dolist (x (file-expand-wildcards
                (concat (funcall swift-project-build-directory-fn swift-project-directory)
                        "*/swift-*/bin/" command)))
         (when (and (file-executable-p x) (or (null newest) (file-newer-than-file-p x newest)))
           (setq newest x)))
       (or newest (executable-find command)))))

 (defvar swift-project-sdk-path
   (substring (shell-command-to-string "xcrun --show-sdk-path") 0 -1)
   "The path to the swift SDK to use for syntax checking, etc.")

 (defvar swift-project--gyb-temp-file-directory nil)
 (defun swift-project-gyb-temp-file-directory ()
   "A directory used for gyb-processed files"
   (or swift-project--gyb-temp-file-directory
       (setq swift-project--gyb-temp-file-directory
             (make-temp-file "swift-project-gyb" :DIRECTORY))))

 (defun swift-project-gyb-output-file-name (input-file-name)
   "Given the name of a .gyb file, return the name of the temporary file we'll use for its expanded result."
   (file-name-sans-extension
    (expand-file-name
     (subst-char-in-string
      ?/ ?! (replace-regexp-in-string
             "!" "!!"
             (if (file-name-absolute-p input-file-name) input-file-name
               (expand-file-name input-file-name))))
     (swift-project-gyb-temp-file-directory))))

 (defun swift-project-gybbed-file (input-file-name)
   "Given the name of a .gyb file, process it with gyb and return an output file name.
 Given any other file name, just return that name."
   (if (not (string-equal (file-name-extension input-file-name) "gyb"))
       input-file-name
     (let ((result (swift-project-gyb-output-file-name input-file-name)))
       (prog1 result
         (unless (file-newer-than-file-p result input-file-name)
           (with-temp-buffer
             (let* ((gyb (swift-project-executable-find "gyb"))
                    (status (call-process gyb nil t nil "-DCMAKE_SIZEOF_VOID_P=8" input-file-name)))
               (unless (eq status 0)
                 (error "%s exited with status %s" gyb status)))
             ;; Use write-region instead of write-file to avoid spewing messages.
             (write-region nil nil result nil 566)))))))

 (defconst swift-project-stdlib-compile-order
   "Algorithm ArrayBody ArrayBuffer ArrayBufferProtocol ArrayCast Arrays ArrayType Assert AssertCommon BidirectionalCollection Bool BridgeObjectiveC BridgeStorage Builtin BuiltinMath Character CocoaArray Collection CollectionAlgorithms Comparable CompilerProtocols ClosedRange ContiguousArrayBuffer CString CTypes DebuggerSupport DropWhile Dump EmptyCollection Equatable ErrorType Existential Filter FixedPoint FlatMap Flatten FloatingPoint FloatingPointParsing FloatingPointTypes Hashable HashedCollections AnyHashable HashedCollectionsAnyHashableExtensions Hashing HeapBuffer ImplicitlyUnwrappedOptional Index Indices InputStream IntegerArithmetic IntegerParsing Integers Join LazyCollection LazySequence LifetimeManager ManagedBuffer Map MemoryLayout Mirrors Misc MutableCollection NewtypeWrapper ObjCMirrors ObjectIdentifier Optional OptionSet OutputStream Pointer Policy PrefixWhile Print RandomAccessCollection Range RangeReplaceableCollection ReflectionLegacy Repeat REPL Reverse Runtime SipHash Sequence SequenceAlgorithms SequenceWrapper SetAlgebra ShadowProtocols Shims Slice Sort StaticString Stride StringCharacterView String StringBridge StringBuffer StringComparable StringCore StringHashable StringInterpolation StringLegacy StringRangeReplaceableCollection StringIndexConversions StringUnicodeScalarView StringUTF16 StringUTF8 SwiftNativeNSArray UnavailableStringAPIs Unicode UnicodeScalar UnicodeTrie Unmanaged UnsafeBitMap UnsafeBufferPointer UnsafeRawBufferPointer UnsafePointer UnsafeRawPointer WriteBackMutableSlice Availability CollectionOfOne ExistentialCollection Mirror CommandLine SliceBuffer Tuple UnfoldSequence VarArgs Zip"

 "Unfortunately, the order in which we send files to the Swift compiler actually matters.  We search this list to determine where each source file should go."
 )

 (defun swift-project-stdlib-compile-order (filename)
   "Return an integer representing where in the required
 compilation order the given file should appear."
   (save-match-data
     (if (string-match
          (concat "\\<" (regexp-quote (replace-regexp-in-string "^\\(?:.*[/!]\\)?\\([^.]*\\).*" "\\1" filename)) "\\>")
          swift-project-stdlib-compile-order)
         (match-beginning 0) 0)))

 (defconst swift-project-common-swiftc-args
   (list "-typecheck" "-sdk" swift-project-sdk-path
         "-F" (concat (file-name-as-directory swift-project-sdk-path) "../../../Developer/Library/Frameworks")
         "-D" "INTERNAL_CHECKS_ENABLED"
         "-no-link-objc-runtime")
   "The common arguments we'll pass to swiftc for syntax-checking
 everything in the Swift project" )

 (defconst swift-project-single-frontend-swiftc-args
   (append swift-project-common-swiftc-args
            (list "-force-single-frontend-invocation" "-parse-as-library"))
   "The arguments we'll pass to swiftc for syntax-checking
 libraries that require a single frontend invocation" )

 (defconst swift-project-stdlib-aux-swiftc-args
   (append swift-project-single-frontend-swiftc-args
           (list "-sil-serialize-vtables" "-parse-stdlib"))
   "swiftc arguments for library components that are compiled as
   though they are part of the standard library even though
   they're not strictly in that binary."  )

 (defconst swift-project-stdlib-swiftc-args
   (append
    swift-project-stdlib-aux-swiftc-args (list "-nostdimport" "-module-name" "Swift"))
   "The arguments we'll pass to swiftc for syntax-checking the
 standard library" )

 (defun swift-project-files-to-compile-with (relative-file)
   "Given RELATIVE-FILE, a project-relative path, returns a list
 of other files that are compiled along with it."
   (if (and (string-match-p "^test/\|^validation-test/" relative-file)
            (not (string-match-p "^test/multifile" relative-file)))
     nil
     (directory-files (concat swift-project-directory (file-name-directory relative-file))))
 )

 (defun swift-project-swiftc-arguments (relative-file)
   "Given RELATIVE-FILE, a project-relative path, returns a list
 of arguments that are passed to swiftc when compiling it."
   (cond ((string-match-p "^stdlib/public/core/" relative-file)
          swift-project-stdlib-swiftc-args)
         ((string-match-p
           "^stdlib/\(public/SwiftOnoneSupport\|internal\|private/SwiftPrivate\(ThreadExtras\|LibcExtras\)?\)/"
           relative-file)
          swift-project-stdlib-aux-swiftc-args)
         (t swift-project-single-frontend-swiftc-args)))

 (defun swift-project-swift-syntax-check (swiftc temp-file)
   "Return a flymake command-line list for syntax-checking the
 current buffer, potentially along with the other .swift and .swift.gyb
 files in the same directory."
   (let ((project-relative-buffer-file (file-relative-name (buffer-file-name) swift-project-directory)))
     (swift-project-gyb-syntax-check1
      swiftc temp-file
      (swift-project-files-to-compile-with project-relative-buffer-file)
      (swift-project-swiftc-arguments project-relative-buffer-file))))

 (defun swift-project-gyb-syntax-check1 (swiftc temp-file other-files swiftc-arguments)
   "Return a flymake command-line list for syntax-checking the
 current buffer along with the other .swift and .swift.gyb
 files in the same directory."
   (let* (gyb-targets swift-sources)
     (dolist (x (cons temp-file other-files))
       (unless (file-equal-p x (buffer-file-name))
         (when (string-match-p "\\.swift$\\|\\.swift\\.gyb$" (if (string-equal x temp-file) (buffer-file-name) x))
           (let ((swift-file (swift-project-gybbed-file x)))
             (setq swift-sources (cons swift-file swift-sources))
             (when (string-equal "gyb" (file-name-extension x))
               (setq gyb-targets (cons swift-file gyb-targets)))))))
     (setq swift-sources
           (sort swift-sources
                 (lambda (x y) (< (swift-project-stdlib-compile-order x)
                                  (swift-project-stdlib-compile-order y)))))
     `(,(swift-project-executable-find "line-directive")
       (,@gyb-targets "--" ,swiftc ,@swiftc-arguments ,@swift-sources))))

 (require 'flymake)
 (add-to-list 'flymake-allowed-file-name-masks '(".+\\.swift.gyb$" flymake-swift-init))

 (provide 'swift-project-settings)
 ;; end of swift-project-settings.el
	;===--- swift-project-settings.el - Swift project's format conventions ---===;
	;
	; This source file is part of the Swift.org open source project
	;
	; Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
	; Licensed under Apache License v2.0 with Runtime Library Exception
	;
	; See https://swift.org/LICENSE.txt for license information
	; See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
	;
	;===----------------------------------------------------------------------===;
	;
	; Emacs-lisp support for automatically formatting things according to this
	; project's conventions. To prevent this file from being automatically
	; loaded, add (provide 'swift-project-settings) to your .emacs
	;
	;===----------------------------------------------------------------------===;


	;; Associate .swift files with swift-mode
	(setq auto-mode-alist
	(append '(("\\.swift$" . swift-mode) ("\\.gyb$" python-mode t)) auto-mode-alist))

	;; Make sure we know where to find swift-mode
	(autoload 'swift-mode (concat (file-name-directory load-file-name) "swift-mode")
	"Major mode for editing SWIFT source files.
	\\{swift-mode-map}
	Runs swift-mode-hook on startup."
	:interactive
	)

	(require 'cc-styles)

	;; This style is appropriate for indenting Swift's C++ source
	(c-add-style "swift"
	'((c-basic-offset . 2)
	(c-offsets-alist
	(namespace-open . 0)
	(template-args-cont c-lineup-template-args +)
	(knr-argdecl-intro . +)
	(substatement-open . +)
	(substatement-label . 2)
	(label . 2)
	(inline-open . +)
	(inexpr-class . +)
	(defun-open . 0)
	(func-decl-cont . +)
	(knr-argdecl . 0)
	(topmost-intro-cont . c-lineup-topmost-intro-cont)
	(annotation-top-cont . 0)
	(annotation-var-cont . +)
	(member-init-cont . c-lineup-multi-inher)
	(block-open . 0)
	(brace-list-open . 0)
	(brace-entry-open . 0)
	(statement-case-open . 0)
	(do-while-closure . 0)
	(catch-clause . 0)
	(stream-op . c-lineup-streamop)
	(cpp-macro-cont . +)
	(friend . 0)
	(objc-method-intro .
	[0])
	(objc-method-args-cont . c-lineup-ObjC-method-args)
	(objc-method-call-cont c-lineup-ObjC-method-call-colons c-lineup-ObjC-method-call +)
	(extern-lang-open . 0)
	(module-open . 0)
	(composition-open . 0)
	(extern-lang-close . 0)
	(module-close . 0)
	(composition-close . 0)
	(inextern-lang . +)
	(inmodule . +)
	(incomposition . +)
	(inlambda . c-lineup-inexpr-block)
	(lambda-intro-cont . +)
	(inexpr-statement . +)
	(topmost-intro . 0)
	(defun-block-intro . +)
	(statement . 0)
	(defun-close . 0)
	(statement-cont . +)
	(brace-list-intro . +)
	(brace-list-entry . 0)
	(brace-list-close . 0)
	(statement-block-intro . +)
	(block-close . 0)
	(innamespace . 0)
	(inher-intro . +)
	(class-open . 0)
	(inclass . +)
	(access-label . 0)
	(member-init-intro . +)
	(substatement . +)
	(inline-close . 0)
	(class-close . 0)
	(namespace-close . 0)
	(case-label . 0)
	(statement-case-intro . +)
	(cpp-define-intro . +)
	(else-clause . 0)
	(arglist-intro . +)
	(arglist-cont . 0)
	(c . c-lineup-C-comments)
	(inher-cont . c-lineup-multi-inher)
	(string . -1000)
	(comment-intro . c-lineup-comment)
	(arglist-cont-nonempty . c-lineup-arglist)
	(arglist-close . c-lineup-close-paren)
	(cpp-macro . -1000))))

	;; When this file is loaded in response to visiting a file in the
	;; project, it won't have had its major mode set up according to the
	;; project settings yet. For example, Swift files may come up in
	;; Fundamental mode, and C++ files won't use the swift style, unless
	;; we do something. This hack causes the file to be re-mode-ed.
	(unless (eq major-mode 'dired-mode) (set-auto-mode))

	(defun swift-project-comment-end ()
	"If comment-end is non-empty returns it, stripped of leading whitespace. Returns nil otherwise"
	(replace-regexp-in-string
	"\\` +" ""
	(if (and comment-end (> (length comment-end) 0)) comment-end v1)))

	(define-skeleton swift-header
	"Insert the Swift header at the top of a file

	Note: this skeleton presently assumes that comment-start creates
	a comment until end-of-line. Handling paired comment syntax is
	possible, but more work, and someone needs to decide what such an
	Swift header should look like.
	"
	;; prompt
	"Short description (RET for none): "

	;; v1 is comment-start without trailing whitespace. Presumably
	;; nobody is crazy enough to define a language where whitespace
	;; determines whether something is a comment, but c++ mode and
	;; friends have a space at the end of comment-start, which messes up
	;; the Swift header format.
	;;
	;; When there's no comment syntax defined, we use "//"; precedent is
	;; in the project's README file.
	'(setq v1 (replace-regexp-in-string " +\\'" "" (or comment-start "//")))

	;; v2 is the name of the file
	'(setq v2 (file-name-nondirectory (buffer-file-name)))
	v1 "===--- " v2
	;; if the short description is empty, eat up the preceding " - "
	" - " str \| -3
	" "
	;; v3 is t if there was a short description
	'(setq v3 (> (length str) 0))

	'(setq v4 (or (swift-project-comment-end) v1))

	;; Generate dashes to fill out the rest of the top line
	(make-string (max (- 65 (+ (if v3 (+ 3 (length str)) 0) (length v2))) 3) ?-)
	"===" v4 "\n"

	;; Use whatever comment character is usual for the current mode in place of "//"
	(replace-regexp-in-string
	"//$" v4
	(replace-regexp-in-string "^//" v1
	"//
	// This source file is part of the Swift.org open source project
	//
	// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
	// Licensed under Apache License v2.0 with Runtime Library Exception
	//
	// See https://swift.org/LICENSE.txt for license information
	// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
	//
	//===----------------------------------------------------------------------===//
	"))
	;; if there was a short description, add a section for a longer
	;; description and leave the cursor there
	(when v3
	(replace-regexp-in-string
	"//$" v4
	(replace-regexp-in-string "^//" v1
	"//
	// ")))
	(when v3 '_)
	(when v3
	(replace-regexp-in-string
	"//$" v4
	(replace-regexp-in-string "^//" v1 "
	//
	//===----------------------------------------------------------------------===//
	")
	)))

	(define-skeleton swift-divider
	"Insert a Swift //===--- ... ---===// divider
	"
	;; prompt
	"Text (RET for none): "

	;; v1 is comment-start without trailing whitespace. Presumably
	;; nobody is crazy enough to define a language where whitespace
	;; determines whether something is a comment, but c++ mode and
	;; friends have a space at the end of comment-start, which messes up
	;; the Swift header format.
	;;
	;; When there's no comment syntax defined, we use "//"; precedent is
	;; in the project's README file.
	'(setq v1 (replace-regexp-in-string " +\\'" "" (or comment-start "//")))

	'(setq v2 (or (swift-project-comment-end) v1))

	v1 "===--- "
	str & " " \| -1
	'(setq v3 (length str))

	;; Generate dashes to fill out the rest of the top line
	(make-string
	(max 3
	(- 77 (current-column) (length v2)))
	?-)

	"===" v2
	)

	(defvar swift-project-auto-insert-alist
	;; Currently we match any file and insert the Swift header. We can
	;; make the regexp more specific or filter based on mode if this
	;; doesn't work out.
	'((("" . "Swift header") . swift-header))
	"auto-insert-alist entries that are just for the Swift project"
	)

	(defadvice auto-insert (around swift-project-auto-insert activate)
	"Modify auto-insert so that swift-project-auto-insert-alist
	takes precedence for files in the Swift project"
	;; Assume that files with c-file-style set to "swift" are
	;; part of the Swift project. Because it's set in
	;; .dir-locals.el, this will apply to all files, not just
	;; those using cc-mode
	(if (and (boundp 'c-file-style) (equal c-file-style "swift"))
	(let ((auto-insert-alist
	(append swift-project-auto-insert-alist auto-insert-alist))
	;; The default is to ask when creating a new file. Inside
	;; this project, we always want the Swift header, so only
	;; prompt if the user has set auto-insert to /always/
	;; prompt.
	(auto-insert-query (if (eq auto-insert-query 'function) nil auto-insert-query)))
	ad-do-it)
	ad-do-it))

	(require 'compile) ;; for compilation-error-regexp-alist et al.
	(push 'swift-stdlibunittest-possibly-expected-assertion compilation-error-regexp-alist)
	(push `(swift-stdlibunittest-possibly-expected-assertion "^\\(\\(?:stdout\\\|stderr\\)>>> \\)?.\\(?:failed\\(?: at\\\|.file\\)\\\|.: file\\) \\([^,]*\\), line \\([0-9]+\\)$"
	2 3 ,(not :column) 0)
	compilation-error-regexp-alist-alist)

	(push 'swift-stdlibunittest-stackframe compilation-error-regexp-alist)
	(push `(swift-stdlibunittest-stackframe "^\\(?:\\(?:stdout\\\|stderr\\)>>> \\)?#[0-9]+: \\(.+\\):\\([0-9]+\\)\\(?: +.\\)?$"
	1 2 ,(not :column) ,(not :just-a-warning))
	compilation-error-regexp-alist-alist)

	(push 'swift-stdlibunittest-failure compilation-error-regexp-alist)
	(push `(swift-stdlibunittest-failure "^\\(?:\\(?:stdout\\\|stderr\\)>>> \\)?check failed at \\(.?\\), line \\([0-9]+\\)$"
	1 2 ,(not :column) ,(not :just-a-warning))
	compilation-error-regexp-alist-alist)

	(defvar swift-project-directory
	(file-name-directory (directory-file-name (file-name-directory load-file-name)))
	"Directory where the swift project containing this file is located.
	Defaults to the parent directory of `swift-project-settings.el'.
	The setting for file-local values of this variable comes from
	.dir-locals.el in the project's root directory")
	(put 'swift-project-directory 'safe-local-variable 'stringp)

	(defun swift-project-default-build-directory (project-directory)
	"Returns the default build directory given a project directory name, `DIR/../build'"
	(concat (file-name-directory (directory-file-name project-directory)) "build/"))

	;; This name doesn't end in "function" to avoid being unconditionally marked as risky.
	(defcustom swift-project-build-directory-fn 'swift-project-default-build-directory
	"A function that, given a swift project directory name,
	computes the directory where your build leaves build products.
	Flymake support may search here for a swift compiler to use, for example.
	Defaults to `(concat swift-project-directory \"../build\")'."
	:type 'function
	)

	(defun swift-project-executable-find (command)
	"Find the newest executable with the given name in the utils/ directory or in any build directory, falling back to the exec-path as a last resort.
	Given an absolute path, returns it verbatim. This is a pretty
	good heuristic for locating things to use when working on swift
	itself, and is used as the value of swift-find-executable-fn"
	(if (file-name-absolute-p command) command
	(let* ((utility (concat swift-project-directory "utils/" command))
	(newest (and (file-executable-p utility) utility)))
	(dolist (x (file-expand-wildcards
	(concat (funcall swift-project-build-directory-fn swift-project-directory)
	"/swift-/bin/" command)))
	(when (and (file-executable-p x) (or (null newest) (file-newer-than-file-p x newest)))
	(setq newest x)))
	(or newest (executable-find command)))))

	(defvar swift-project-sdk-path
	(substring (shell-command-to-string "xcrun --show-sdk-path") 0 -1)
	"The path to the swift SDK to use for syntax checking, etc.")

	(defvar swift-project--gyb-temp-file-directory nil)
	(defun swift-project-gyb-temp-file-directory ()
	"A directory used for gyb-processed files"
	(or swift-project--gyb-temp-file-directory
	(setq swift-project--gyb-temp-file-directory
	(make-temp-file "swift-project-gyb" :DIRECTORY))))

	(defun swift-project-gyb-output-file-name (input-file-name)
	"Given the name of a .gyb file, return the name of the temporary file we'll use for its expanded result."
	(file-name-sans-extension
	(expand-file-name
	(subst-char-in-string
	?/ ?! (replace-regexp-in-string
	"!" "!!"
	(if (file-name-absolute-p input-file-name) input-file-name
	(expand-file-name input-file-name))))
	(swift-project-gyb-temp-file-directory))))

	(defun swift-project-gybbed-file (input-file-name)
	"Given the name of a .gyb file, process it with gyb and return an output file name.
	Given any other file name, just return that name."
	(if (not (string-equal (file-name-extension input-file-name) "gyb"))
	input-file-name
	(let ((result (swift-project-gyb-output-file-name input-file-name)))
	(prog1 result
	(unless (file-newer-than-file-p result input-file-name)
	(with-temp-buffer
	(let* ((gyb (swift-project-executable-find "gyb"))
	(status (call-process gyb nil t nil "-DCMAKE_SIZEOF_VOID_P=8" input-file-name)))
	(unless (eq status 0)
	(error "%s exited with status %s" gyb status)))
	;; Use write-region instead of write-file to avoid spewing messages.
	(write-region nil nil result nil 566)))))))

	(defconst swift-project-stdlib-compile-order
	"Algorithm ArrayBody ArrayBuffer ArrayBufferProtocol ArrayCast Arrays ArrayType Assert AssertCommon BidirectionalCollection Bool BridgeObjectiveC BridgeStorage Builtin BuiltinMath Character CocoaArray Collection CollectionAlgorithms Comparable CompilerProtocols ClosedRange ContiguousArrayBuffer CString CTypes DebuggerSupport DropWhile Dump EmptyCollection Equatable ErrorType Existential Filter FixedPoint FlatMap Flatten FloatingPoint FloatingPointParsing FloatingPointTypes Hashable HashedCollections AnyHashable HashedCollectionsAnyHashableExtensions Hashing HeapBuffer ImplicitlyUnwrappedOptional Index Indices InputStream IntegerArithmetic IntegerParsing Integers Join LazyCollection LazySequence LifetimeManager ManagedBuffer Map MemoryLayout Mirrors Misc MutableCollection NewtypeWrapper ObjCMirrors ObjectIdentifier Optional OptionSet OutputStream Pointer Policy PrefixWhile Print RandomAccessCollection Range RangeReplaceableCollection ReflectionLegacy Repeat REPL Reverse Runtime SipHash Sequence SequenceAlgorithms SequenceWrapper SetAlgebra ShadowProtocols Shims Slice Sort StaticString Stride StringCharacterView String StringBridge StringBuffer StringComparable StringCore StringHashable StringInterpolation StringLegacy StringRangeReplaceableCollection StringIndexConversions StringUnicodeScalarView StringUTF16 StringUTF8 SwiftNativeNSArray UnavailableStringAPIs Unicode UnicodeScalar UnicodeTrie Unmanaged UnsafeBitMap UnsafeBufferPointer UnsafeRawBufferPointer UnsafePointer UnsafeRawPointer WriteBackMutableSlice Availability CollectionOfOne ExistentialCollection Mirror CommandLine SliceBuffer Tuple UnfoldSequence VarArgs Zip"

	"Unfortunately, the order in which we send files to the Swift compiler actually matters. We search this list to determine where each source file should go."
	)

	(defun swift-project-stdlib-compile-order (filename)
	"Return an integer representing where in the required
	compilation order the given file should appear."
	(save-match-data
	(if (string-match
	(concat "\\<" (regexp-quote (replace-regexp-in-string "^\\(?:.[/!]\\)?\\([^.]\\).*" "\\1" filename)) "\\>")
	swift-project-stdlib-compile-order)
	(match-beginning 0) 0)))

	(defconst swift-project-common-swiftc-args
	(list "-typecheck" "-sdk" swift-project-sdk-path
	"-F" (concat (file-name-as-directory swift-project-sdk-path) "../../../Developer/Library/Frameworks")
	"-D" "INTERNAL_CHECKS_ENABLED"
	"-no-link-objc-runtime")
	"The common arguments we'll pass to swiftc for syntax-checking
	everything in the Swift project" )

	(defconst swift-project-single-frontend-swiftc-args
	(append swift-project-common-swiftc-args
	(list "-force-single-frontend-invocation" "-parse-as-library"))
	"The arguments we'll pass to swiftc for syntax-checking
	libraries that require a single frontend invocation" )

	(defconst swift-project-stdlib-aux-swiftc-args
	(append swift-project-single-frontend-swiftc-args
	(list "-sil-serialize-vtables" "-parse-stdlib"))
	"swiftc arguments for library components that are compiled as
	though they are part of the standard library even though
	they're not strictly in that binary." )

	(defconst swift-project-stdlib-swiftc-args
	(append
	swift-project-stdlib-aux-swiftc-args (list "-nostdimport" "-module-name" "Swift"))
	"The arguments we'll pass to swiftc for syntax-checking the
	standard library" )

	(defun swift-project-files-to-compile-with (relative-file)
	"Given RELATIVE-FILE, a project-relative path, returns a list
	of other files that are compiled along with it."
	(if (and (string-match-p "^test/\\|^validation-test/" relative-file)
	(not (string-match-p "^test/multifile" relative-file)))
	nil
	(directory-files (concat swift-project-directory (file-name-directory relative-file))))
	)

	(defun swift-project-swiftc-arguments (relative-file)
	"Given RELATIVE-FILE, a project-relative path, returns a list
	of arguments that are passed to swiftc when compiling it."
	(cond ((string-match-p "^stdlib/public/core/" relative-file)
	swift-project-stdlib-swiftc-args)
	((string-match-p
	"^stdlib/\(public/SwiftOnoneSupport\\|internal\\|private/SwiftPrivate\(ThreadExtras\\|LibcExtras\)?\)/"
	relative-file)
	swift-project-stdlib-aux-swiftc-args)
	(t swift-project-single-frontend-swiftc-args)))

	(defun swift-project-swift-syntax-check (swiftc temp-file)
	"Return a flymake command-line list for syntax-checking the
	current buffer, potentially along with the other .swift and .swift.gyb
	files in the same directory."
	(let ((project-relative-buffer-file (file-relative-name (buffer-file-name) swift-project-directory)))
	(swift-project-gyb-syntax-check1
	swiftc temp-file
	(swift-project-files-to-compile-with project-relative-buffer-file)
	(swift-project-swiftc-arguments project-relative-buffer-file))))

	(defun swift-project-gyb-syntax-check1 (swiftc temp-file other-files swiftc-arguments)
	"Return a flymake command-line list for syntax-checking the
	current buffer along with the other .swift and .swift.gyb
	files in the same directory."
	(let* (gyb-targets swift-sources)
	(dolist (x (cons temp-file other-files))
	(unless (file-equal-p x (buffer-file-name))
	(when (string-match-p "\\.swift$\\\|\\.swift\\.gyb$" (if (string-equal x temp-file) (buffer-file-name) x))
	(let ((swift-file (swift-project-gybbed-file x)))
	(setq swift-sources (cons swift-file swift-sources))
	(when (string-equal "gyb" (file-name-extension x))
	(setq gyb-targets (cons swift-file gyb-targets)))))))
	(setq swift-sources
	(sort swift-sources
	(lambda (x y) (< (swift-project-stdlib-compile-order x)
	(swift-project-stdlib-compile-order y)))))
	`(,(swift-project-executable-find "line-directive")
	(,@gyb-targets "--" ,swiftc ,@swiftc-arguments ,@swift-sources))))

	(require 'flymake)
	(add-to-list 'flymake-allowed-file-name-masks '(".+\\.swift.gyb$" flymake-swift-init))

	(provide 'swift-project-settings)
	;; end of swift-project-settings.el