Allow _clang-format as alternative to .clang-format config filename

Dotfiles are impractical on Windows. This makes clang-format search
for the style configuration file as '_clang-format' in addition to
the usual '.clang-format'. This is similar to how VIM searches for
'_vimrc' on Windows.

Differential Revision: http://llvm-reviews.chandlerc.com/D1629

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190413 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 14 insertions, 2 deletions

diff --git a/tools/clang-format/ClangFormat.cpp b/tools/clang-format/ClangFormat.cpp
index 2d415b358f..592d46a530 100644
--- a/tools/clang-format/ClangFormat.cpp
+++ b/tools/clang-format/ClangFormat.cpp
@@ -132,12 +132,22 @@ FormatStyle getStyle(StringRef StyleName, StringRef FileName) {
        !Directory.empty();
        Directory = llvm::sys::path::parent_path(Directory)) {
     SmallString<128> ConfigFile(Directory);
+
     llvm::sys::path::append(ConfigFile, ".clang-format");
     DEBUG(llvm::dbgs() << "Trying " << ConfigFile << "...\n");
     bool IsFile = false;
     // Ignore errors from is_regular_file: we only need to know if we can read
     // the file or not.
     llvm::sys::fs::is_regular_file(Twine(ConfigFile), IsFile);
+
+    if (!IsFile) {
+      // Try _clang-format too, since dotfiles are not commonly used on Windows.
+      ConfigFile = Directory;
+      llvm::sys::path::append(ConfigFile, "_clang-format");
+      DEBUG(llvm::dbgs() << "Trying " << ConfigFile << "...\n");
+      llvm::sys::fs::is_regular_file(Twine(ConfigFile), IsFile);
+    }
+
     if (IsFile) {
       OwningPtr<MemoryBuffer> Text;
       if (error_code ec = MemoryBuffer::getFile(ConfigFile, Text)) {
diff --git a/tools/clang-format/clang-format-sublime.py b/tools/clang-format/clang-format-sublime.py
index 73ff3dc823..78c8939c1b 100644
--- a/tools/clang-format/clang-format-sublime.py
+++ b/tools/clang-format/clang-format-sublime.py
@@ -21,7 +21,8 @@ binary = 'clang-format'
 
 # Change this to format according to other formatting styles. See the output of
 # 'clang-format --help' for a list of supported styles. The default looks for
-# a '.clang-format' file to indicate the style that should be used.
+# a '.clang-format' or '_clang-format' file to indicate the style that should be
+# used.
 style = 'file'
 
 class ClangFormatCommand(sublime_plugin.TextCommand):
diff --git a/tools/clang-format/clang-format.py b/tools/clang-format/clang-format.py
index 4077b4180c..d8338ab4da 100644
--- a/tools/clang-format/clang-format.py
+++ b/tools/clang-format/clang-format.py
@@ -28,7 +28,8 @@ binary = 'clang-format'
 
 # Change this to format according to other formatting styles. See the output of
 # 'clang-format --help' for a list of supported styles. The default looks for
-# a '.clang-format' file to indicate the style that should be used.
+# a '.clang-format' or '_clang-format' file to indicate the style that should be
+# used.
 style = 'file'
 
 # Get the current text.