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.

llvm-svn: 190691

1 files changed, 13 insertions, 1 deletions

diff --git a/clang/tools/clang-format/ClangFormat.cpp b/clang/tools/clang-format/ClangFormat.cpp
index 592d46a530c..71dcfc5640b 100644
--- a/clang/tools/clang-format/ClangFormat.cpp
+++ b/clang/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");