r325722 - [clang-format] Fix regression when getStyle() called with empty filename

[Ben Hamilton via cfe-commits]

Author: benhamilton
Date: Wed Feb 21 13:27:27 2018
New Revision: 325722

URL: http://llvm.org/viewvc/llvm-project?rev=325722&view=rev
Log:
[clang-format] Fix regression when getStyle() called with empty filename

Summary:
D43522 caused an assertion failure when getStyle() was called with
an empty filename:

P8065

This adds a test to reproduce the failure and fixes the issue by
ensuring we never pass an empty filename to
Environment::CreateVirtualEnvironment().

Test Plan: New test added. Ran test with:
  % make -j12 FormatTests && ./tools/clang/unittests/Format/FormatTests
  Before diff, test failed with P8065. Now, test passes.

Reviewers: vsapsai, jolesiak, krasimir

Reviewed By: vsapsai

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D43590

Modified:
    cfe/trunk/lib/Format/Format.cpp
    cfe/trunk/unittests/Format/FormatTest.cpp

Modified: cfe/trunk/lib/Format/Format.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Format/Format.cpp?rev=325722&r1=325721&r2=325722&view=diff
==============================================================================
--- cfe/trunk/lib/Format/Format.cpp (original)
+++ cfe/trunk/lib/Format/Format.cpp Wed Feb 21 13:27:27 2018
@@ -2297,12 +2297,13 @@ static FormatStyle::LanguageKind getLang
 FormatStyle::LanguageKind guessLanguage(StringRef FileName, StringRef Code) {
   FormatStyle::LanguageKind result = getLanguageByFileName(FileName);
   if (result == FormatStyle::LK_Cpp) {
-    auto extension = llvm::sys::path::extension(FileName);
+    auto Extension = llvm::sys::path::extension(FileName);
     // If there's no file extension (or it's .h), we need to check the contents
     // of the code to see if it contains Objective-C.
-    if (extension.empty() || extension == ".h") {
+    if (Extension.empty() || Extension == ".h") {
+      auto NonEmptyFileName = FileName.empty() ? "guess.h" : FileName;
       std::unique_ptr<Environment> Env =
-          Environment::CreateVirtualEnvironment(Code, FileName, /*Ranges=*/{});
+          Environment::CreateVirtualEnvironment(Code, NonEmptyFileName, /*Ranges=*/{});
       ObjCHeaderStyleGuesser Guesser(*Env, getLLVMStyle());
       Guesser.process();
       if (Guesser.isObjC()) {

Modified: cfe/trunk/unittests/Format/FormatTest.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Format/FormatTest.cpp?rev=325722&r1=325721&r2=325722&view=diff
==============================================================================
--- cfe/trunk/unittests/Format/FormatTest.cpp (original)
+++ cfe/trunk/unittests/Format/FormatTest.cpp Wed Feb 21 13:27:27 2018
@@ -11723,6 +11723,12 @@ TEST_F(FormatTest, NoSpaceAfterSuper) {
     verifyFormat("__super::FooBar();");
 }
 
+TEST(FormatStyle, GetStyleWithEmptyFileName) {
+  auto Style1 = getStyle("file", "", "Google");
+  ASSERT_TRUE((bool)Style1);
+  ASSERT_EQ(*Style1, getGoogleStyle());
+}
+
 TEST(FormatStyle, GetStyleOfFile) {
   vfs::InMemoryFileSystem FS;
   // Test 1: format file in the same directory.