Index: include/clang/Format/Format.h
===================================================================
--- include/clang/Format/Format.h
+++ include/clang/Format/Format.h
@@ -1843,7 +1843,7 @@
 ///
 /// Returns ``true`` if the Style has been set.
 bool getPredefinedStyle(StringRef Name, FormatStyle::LanguageKind Language,
-                        FormatStyle *Style);
+                        FormatStyle *Style, vfs::FileSystem *FS = nullptr);
 
 /// Parse configuration from YAML-formatted text.
 ///
Index: lib/Basic/VirtualFileSystem.cpp
===================================================================
--- lib/Basic/VirtualFileSystem.cpp
+++ lib/Basic/VirtualFileSystem.cpp
@@ -285,7 +285,7 @@
 std::error_code
 RealFileSystem::getRealPath(const Twine &Path,
                             SmallVectorImpl<char> &Output) const {
-  return llvm::sys::fs::real_path(Path, Output);
+  return llvm::sys::fs::real_path(Path, Output, true);
 }
 
 IntrusiveRefCntPtr<FileSystem> vfs::getRealFileSystem() {
Index: lib/Format/Format.cpp
===================================================================
--- lib/Format/Format.cpp
+++ lib/Format/Format.cpp
@@ -928,8 +928,42 @@
   return NoStyle;
 }
 
+// Try loading config file from path, in argument to -style and BasedOnStyle.
+bool loadSystemStyle(StringRef Name, FormatStyle *Style,
+                     vfs::FileSystem *FS = nullptr) {
+  if (!FS) {
+    FS = vfs::getRealFileSystem().get();
+  }
+  const llvm::SmallVector<Twine, 3> paths = {
+    {"/usr/local/share/clang-format/", Name},
+    {"~/.local/share/clang-format/", Name},
+    Name
+  };
+  for (Twine Path: paths) {
+    llvm::SmallVector<char, 100> RealPath;
+    Twine ConfigFile{!FS->getRealPath(Path, RealPath) ? RealPath : Path};
+    if (FS->exists(ConfigFile)) {
+      llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Text =
+          FS->getBufferForFile(ConfigFile);
+      if (std::error_code EC = Text.getError()) {
+        LLVM_DEBUG(llvm::dbgs() << "Error reading " << ConfigFile << ": "
+                   << EC.message() << "\n");
+        return false;
+      }
+      if (std::error_code EC =
+              parseConfiguration(Text.get()->getBuffer(), Style)) {
+          LLVM_DEBUG(llvm::dbgs() << "Error parsing " << ConfigFile << ": "
+                     << EC.message() << "\n");
+        return false;
+      }
+      return true;
+    }
+  }
+  return false;
+}
+
 bool getPredefinedStyle(StringRef Name, FormatStyle::LanguageKind Language,
-                        FormatStyle *Style) {
+                        FormatStyle *Style, vfs::FileSystem *FS) {
   if (Name.equals_lower("llvm")) {
     *Style = getLLVMStyle();
   } else if (Name.equals_lower("chromium")) {
@@ -944,7 +978,7 @@
     *Style = getGNUStyle();
   } else if (Name.equals_lower("none")) {
     *Style = getNoStyle();
-  } else {
+  } else if (!loadSystemStyle(Name, Style, FS)) {
     return false;
   }
 
@@ -2103,13 +2137,16 @@
 const char *StyleOptionHelpDescription =
     "Coding style, currently supports:\n"
     "  LLVM, Google, Chromium, Mozilla, WebKit.\n"
+    "Additional styles can be installed in /usr/local/share/clang-format\n"
+    "or ~/.local/share/clang-format.\n"
     "Use -style=file to load style configuration from\n"
     ".clang-format file located in one of the parent\n"
     "directories of the source file (or current\n"
     "directory for stdin).\n"
     "Use -style=\"{key: value, ...}\" to set specific\n"
     "parameters, e.g.:\n"
-    "  -style=\"{BasedOnStyle: llvm, IndentWidth: 8}\"";
+    "  -style=\"{BasedOnStyle: llvm, IndentWidth: 8}\""
+    "Other value of the parameter must the path of the config file to load";
 
 static FormatStyle::LanguageKind getLanguageByFileName(StringRef FileName) {
   if (FileName.endswith(".java"))
@@ -2174,7 +2211,7 @@
   }
 
   if (!StyleName.equals_lower("file")) {
-    if (!getPredefinedStyle(StyleName, Style.Language, &Style))
+    if (!getPredefinedStyle(StyleName, Style.Language, &Style, FS))
       return make_string_error("Invalid value for -style");
     return Style;
   }
Index: unittests/Format/FormatTest.cpp
===================================================================
--- unittests/Format/FormatTest.cpp
+++ unittests/Format/FormatTest.cpp
@@ -12113,6 +12113,61 @@
   ASSERT_EQ(*Style1, getGoogleStyle());
 }
 
+TEST(FormatStyle, GetExternalStyle) {
+  vfs::InMemoryFileSystem FS;
+  // Test 1: format file in /usr/local/share/clang-format/
+  ASSERT_TRUE(
+      FS.addFile("/usr/local/share/clang-format/style1", 0,
+                 llvm::MemoryBuffer::getMemBuffer("BasedOnStyle: Google")));
+  auto Style1 = getStyle("style1", "", "LLVM", "", &FS);
+  ASSERT_TRUE((bool)Style1);
+  ASSERT_EQ(*Style1, getGoogleStyle());
+
+  // Test 2: format file in ~/.local/share/clang-format/
+  ASSERT_TRUE(
+      FS.addFile("~/.local/share/clang-format/style2", 0,
+                 llvm::MemoryBuffer::getMemBuffer("BasedOnStyle: Google")));
+  auto Style2 = getStyle("style2", "", "LLVM", "", &FS);
+  ASSERT_TRUE((bool)Style2);
+  ASSERT_EQ(*Style2, getGoogleStyle());
+
+  // Test 3: format file in absolute path
+  ASSERT_TRUE(
+      FS.addFile("/clang-format-styles/style3", 0,
+                 llvm::MemoryBuffer::getMemBuffer("BasedOnStyle: Google")));
+  auto Style3 = getStyle("/clang-format-styles/style3", "", "LLVM", "", &FS);
+  ASSERT_TRUE((bool)Style3);
+  ASSERT_EQ(*Style3, getGoogleStyle());
+
+  // Test 4: format file in relative path
+  ASSERT_TRUE(
+      FS.addFile("/home/clang-format-styles/style4", 0,
+                 llvm::MemoryBuffer::getMemBuffer("BasedOnStyle: Google")));
+  FS.setCurrentWorkingDirectory("/home/clang-format-styles");
+  auto Style4 = getStyle("style4", "", "LLVM", "", &FS);
+  ASSERT_TRUE((bool)Style4);
+  ASSERT_EQ(*Style4, getGoogleStyle());
+
+  // Test 5: file does not exist
+  auto Style5 = getStyle("style5", "", "LLVM", "", &FS);
+  ASSERT_FALSE((bool)Style5);
+  llvm::consumeError(Style5.takeError());
+
+  // Test 6: absolute file does not exist
+  auto Style6 = getStyle("/style6", "", "LLVM", "", &FS);
+  ASSERT_FALSE((bool)Style6);
+  llvm::consumeError(Style6.takeError());
+
+  // Test 7: file is not a format style
+  ASSERT_TRUE(
+      FS.addFile("/usr/local/share/clang-format/nostyle", 0,
+                 llvm::MemoryBuffer::getMemBuffer("This is not a style...")));
+  FS.setCurrentWorkingDirectory("/home/clang-format-styles");
+  auto Style7 = getStyle("nostyle", "", "LLVM", "", &FS);
+  ASSERT_FALSE((bool)Style7);
+  llvm::consumeError(Style7.takeError());
+}
+
 TEST(FormatStyle, GetStyleOfFile) {
   vfs::InMemoryFileSystem FS;
   // Test 1: format file in the same directory.