clang-format: Add -assume-filename option for editor integrations.

With -style=file, clang-format now starts to search for a .clang-format
file starting at the file given with -assume-filename if it reads from
stdin. Otherwise, it would start searching from the current directory,
which is not helpful for editor integrations.

Also changed vim, emacs and sublime integrations to actually make use of
this flag.

This fixes llvm.org/PR17072.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190691 91177308-0d34-0410-b5e6-96231b3b80d8

tools/clang-format/ClangFormat.cpp

@@ -73,6 +73,14 @@ static cl::opt<std::string>
                    "parameters, e.g.:\n"
                    "  -style=\"{BasedOnStyle: llvm, IndentWidth: 8}\""),
           cl::init("file"), cl::cat(ClangFormatCategory));
+
+static cl::opt<std::string>
+AssumeFilename("assume-filename",
+               cl::desc("When reading from stdin, clang-format assumes this\n"
+                        "filename to look for a style config file (with\n"
+                        "-style=file)."),
+               cl::cat(ClangFormatCategory));
+
 static cl::opt<bool> Inplace("i",
                              cl::desc("Inplace edit <file>s, if specified."),
                              cl::cat(ClangFormatCategory));
@@ -126,11 +134,15 @@ FormatStyle getStyle(StringRef StyleName, StringRef FileName) {
     return Style;
   }
 
+  if (FileName == "-")
+    FileName = AssumeFilename;
   SmallString<128> Path(FileName);
   llvm::sys::fs::make_absolute(Path);
-  for (StringRef Directory = llvm::sys::path::parent_path(Path);
+  for (StringRef Directory = Path;
        !Directory.empty();
        Directory = llvm::sys::path::parent_path(Directory)) {
+    if (!llvm::sys::fs::is_directory(Directory))
+      continue;
     SmallString<128> ConfigFile(Directory);
 
     llvm::sys::path::append(ConfigFile, ".clang-format");

tools/clang-format/clang-format-sublime.py

@@ -37,21 +37,21 @@ class ClangFormatCommand(sublime_plugin.TextCommand):
       region_offset = min(region.a, region.b)
       region_length = abs(region.b - region.a)
       command.extend(['-offset', str(region_offset),
-                      '-length', str(region_length)])
+                      '-length', str(region_length),
+                      '-assume-filename', str(self.view.file_name())])
     old_viewport_position = self.view.viewport_position()
     buf = self.view.substr(sublime.Region(0, self.view.size()))
     p = subprocess.Popen(command, stdout=subprocess.PIPE,
                          stderr=subprocess.PIPE, stdin=subprocess.PIPE)
     output, error = p.communicate(buf.encode(encoding))
-    if not error:
-      self.view.replace(
-          edit, sublime.Region(0, self.view.size()),
-          output.decode(encoding))
-      self.view.sel().clear()
-      for region in regions:
-        self.view.sel().add(region)
-      # FIXME: Without the 10ms delay, the viewport sometimes jumps.
-      sublime.set_timeout(lambda: self.view.set_viewport_position(
-        old_viewport_position, False), 10)
-    else:
+    if error:
       print error
+    self.view.replace(
+        edit, sublime.Region(0, self.view.size()),
+        output.decode(encoding))
+    self.view.sel().clear()
+    for region in regions:
+      self.view.sel().add(region)
+    # FIXME: Without the 10ms delay, the viewport sometimes jumps.
+    sublime.set_timeout(lambda: self.view.set_viewport_position(
+      old_viewport_position, False), 10)

tools/clang-format/clang-format.el

@@ -38,10 +38,12 @@
          (orig-point (point))
          (style "file"))
     (unwind-protect
-        (call-process-region (point-min) (point-max) clang-format-binary t t nil
+        (call-process-region (point-min) (point-max) clang-format-binary
+                             t (list t nil) nil
                              "-offset" (number-to-string (1- begin))
                              "-length" (number-to-string (- end begin))
                              "-cursor" (number-to-string (1- (point)))
+                             "-assume-filename" (buffer-file-name)
                              "-style" style)
       (goto-char (point-min))
       (let ((json-output (json-read-from-string

tools/clang-format/clang-format.py

@@ -49,7 +49,8 @@ if sys.platform.startswith('win32'):
 
 # Call formatter.
 p = subprocess.Popen([binary, '-lines', lines, '-style', style,
-                      '-cursor', str(cursor)],
+                      '-cursor', str(cursor),
+                      '-assume-filename', vim.current.buffer.name],
                      stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                      stdin=subprocess.PIPE, startupinfo=startupinfo)
 stdout, stderr = p.communicate(input=text)