Added support for different VFSs in format::getStyle.

[ioeric]

Summary

Previously, format::getStyle assumes that the given file resides in
the real file system, which prevents the use of virtual file system in testing etc.
This patch adds a parameter in format::getStyle interface so that users can specify
the right file system. By default, the file system is the real file system.

[klimek]

lib/Format/Format.cpp

2103 ↗

(On Diff #51425)

I think this comment is redundant. I'd remove it.

2149 ↗

(On Diff #51425)

Any reason to not just reassign Status (here and below)?

2157 ↗

(On Diff #51425)

I'm aware you didn't change this, but is Twine() really necessary?

[ioeric]

• removed redundant code.

[ioeric]

• some more redundancy removed

[klimek]

lib/Format/Format.cpp

2148 ↗

(On Diff #51431)

Prefer .str to .c_str, the former is nicely typed. (here and below)

[ioeric]

• changed c_str() to str()

[klimek]

lg

cfe/trunk/include/clang/Format/Format.h

 /// Various functions to configurably format source code.
 ///
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_FORMAT_FORMAT_H
 #define LLVM_CLANG_FORMAT_FORMAT_H
 
 #include "clang/Basic/LangOptions.h"
+#include "clang/Basic/VirtualFileSystem.h"
 #include "clang/Tooling/Core/Replacement.h"
 #include "llvm/ADT/ArrayRef.h"
 #include <system_error>
 
 namespace clang {
 
 class Lexer;
 class SourceManager;

 /// directory if ``FileName`` is empty.
 ///
 /// \param[in] StyleName Style name to interpret according to the description
 /// above.
 /// \param[in] FileName Path to start search for .clang-format if ``StyleName``
 /// == "file".
 /// \param[in] FallbackStyle The name of a predefined style used to fallback to
 /// in case the style can't be determined from \p StyleName.
+/// \param[in] FS The underlying file system, in which the file resides. By
+/// default, the file system is the real file system.
 ///
 /// \returns FormatStyle as specified by ``StyleName``. If no style could be
 /// determined, the default is LLVM Style (see ``getLLVMStyle()``).
 FormatStyle getStyle(StringRef StyleName, StringRef FileName,
-                     StringRef FallbackStyle);
+                     StringRef FallbackStyle, vfs::FileSystem *FS = nullptr);
 
 } // end namespace format
 } // end namespace clang
 
 namespace std {
 template <>
 struct is_error_code_enum<clang::format::ParseError> : std::true_type {};
 }
 
 #endif // LLVM_CLANG_FORMAT_FORMAT_H

cfe/trunk/lib/Format/Format.cpp

if (FileName.endswith_lower(".proto") ||
       FileName.endswith_lower(".protodevel"))
     return FormatStyle::LK_Proto;
   if (FileName.endswith_lower(".td"))
     return FormatStyle::LK_TableGen;
   return FormatStyle::LK_Cpp;
 }
 
 FormatStyle getStyle(StringRef StyleName, StringRef FileName,
-                     StringRef FallbackStyle) {
+                     StringRef FallbackStyle, vfs::FileSystem *FS) {
+  if (!FS) {
+    FS = vfs::getRealFileSystem().get();
+  }
   FormatStyle Style = getLLVMStyle();
   Style.Language = getLanguageByFileName(FileName);
   if (!getPredefinedStyle(FallbackStyle, Style.Language, &Style)) {
     llvm::errs() << "Invalid fallback style \"" << FallbackStyle
                  << "\" using LLVM style\n";
     return Style;
   }
 
FormatStyle getStyle(StringRef StyleName, StringRef FileName,
   }
 
   // Look for .clang-format/_clang-format file in the file's parent directories.
   SmallString<128> UnsuitableConfigFiles;
   SmallString<128> Path(FileName);
   llvm::sys::fs::make_absolute(Path);
   for (StringRef Directory = Path; !Directory.empty();
        Directory = llvm::sys::path::parent_path(Directory)) {
-    if (!llvm::sys::fs::is_directory(Directory))
+
+    auto Status = FS->status(Directory);
+    if (!Status ||
+        Status->getType() != llvm::sys::fs::file_type::directory_file) {
       continue;
+    }
+
     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);
-
+    Status = FS->status(ConfigFile.str());
+    bool IsFile =
+        Status && (Status->getType() == llvm::sys::fs::file_type::regular_file);
     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);
+      Status = FS->status(ConfigFile.str());
+      IsFile = Status &&
+               (Status->getType() == llvm::sys::fs::file_type::regular_file);
     }
 
     if (IsFile) {
       llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Text =
-          llvm::MemoryBuffer::getFile(ConfigFile.c_str());
+          FS->getBufferForFile(ConfigFile.str());
       if (std::error_code EC = Text.getError()) {
         llvm::errs() << EC.message() << "\n";
         break;
       }
       if (std::error_code ec =
               parseConfiguration(Text.get()->getBuffer(), &Style)) {
         if (ec == ParseError::Unsuitable) {
           if (!UnsuitableConfigFiles.empty())

cfe/trunk/unittests/Format/FormatTest.cpp

 //===- unittest/Format/FormatTest.cpp - Formatting unit tests -------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Format/Format.h"
 
 #include "../Tooling/RewriterTestContext.h"
 #include "FormatTestUtils.h"
 
 #include "clang/Frontend/TextDiagnosticPrinter.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/MemoryBuffer.h"
 #include "gtest/gtest.h"
 
 #define DEBUG_TYPE "format-test"
 
 namespace clang {
 namespace format {
 namespace {
 

 }
 
 TEST_F(FormatTest, FormatsTableGenCode) {
   FormatStyle Style = getLLVMStyle();
   Style.Language = FormatStyle::LK_TableGen;
   verifyFormat("include \"a.td\"\ninclude \"b.td\"", Style);
 }
 
+TEST(FormatStyle, GetStyleOfFile) {
+  vfs::InMemoryFileSystem FS;
+  // Test 1: format file in the same directory.
+  ASSERT_TRUE(
+      FS.addFile("/a/.clang-format", 0,
+                 llvm::MemoryBuffer::getMemBuffer("BasedOnStyle: LLVM")));
+  ASSERT_TRUE(
+      FS.addFile("/a/test.cpp", 0, llvm::MemoryBuffer::getMemBuffer("int i;")));
+  auto Style1 = getStyle("file", "/a/.clang-format", "Google", &FS);
+  ASSERT_EQ(Style1, getLLVMStyle());
+
+  // Test 2: fallback to default.
+  ASSERT_TRUE(
+      FS.addFile("/b/test.cpp", 0, llvm::MemoryBuffer::getMemBuffer("int i;")));
+  auto Style2 = getStyle("file", "/b/test.cpp", "Mozilla", &FS);
+  ASSERT_EQ(Style2, getMozillaStyle());
+
+  // Test 3: format file in parent directory.
+  ASSERT_TRUE(
+      FS.addFile("/c/.clang-format", 0,
+                 llvm::MemoryBuffer::getMemBuffer("BasedOnStyle: Google")));
+  ASSERT_TRUE(FS.addFile("/c/sub/sub/sub/test.cpp", 0,
+                         llvm::MemoryBuffer::getMemBuffer("int i;")));
+  auto Style3 = getStyle("file", "/c/sub/sub/sub/test.cpp", "LLVM", &FS);
+  ASSERT_EQ(Style3, getGoogleStyle());
+}
+
 class ReplacementTest : public ::testing::Test {
 protected:
   tooling::Replacement createReplacement(SourceLocation Start, unsigned Length,
                                          llvm::StringRef ReplacementText) {
     return tooling::Replacement(Context.Sources, Start, Length,
                                 ReplacementText);
   }