1 files changed, 120 insertions, 0 deletions
diff --git a/clang/unittests/Tooling/RewriterTestContext.h b/clang/unittests/Tooling/RewriterTestContext.h
new file mode 100644
index 00000000000..eecb1d0cb89
--- /dev/null
+++ b/clang/unittests/Tooling/RewriterTestContext.h
@@ -0,0 +1,120 @@
+//===--- RewriterTestContext.h ----------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines a utility class for Rewriter related tests.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_REWRITER_TEST_CONTEXT_H
+#define LLVM_CLANG_REWRITER_TEST_CONTEXT_H
+
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/DiagnosticOptions.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Rewrite/Rewriter.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace clang {
+
+/// \brief A class that sets up a ready to use Rewriter.
+///
+/// Useful in unit tests that need a Rewriter. Creates all dependencies
+/// of a Rewriter with default values for testing and provides convenience
+/// methods, which help with writing tests that change files.
+class RewriterTestContext {
+ public:
+  RewriterTestContext()
+      : Diagnostics(llvm::IntrusiveRefCntPtr<DiagnosticIDs>()),
+        DiagnosticPrinter(llvm::outs(), DiagnosticOptions()),
+        Files((FileSystemOptions())),
+        Sources(Diagnostics, Files),
+        Rewrite(Sources, Options) {
+    Diagnostics.setClient(&DiagnosticPrinter, false);
+  }
+
+  ~RewriterTestContext() {
+    if (TemporaryDirectory.isValid()) {
+      std::string ErrorInfo;
+      TemporaryDirectory.eraseFromDisk(true, &ErrorInfo);
+      assert(ErrorInfo.empty());
+    }
+  }
+
+  FileID createInMemoryFile(StringRef Name, StringRef Content) {
+    const llvm::MemoryBuffer *Source =
+      llvm::MemoryBuffer::getMemBuffer(Content);
+    const FileEntry *Entry =
+      Files.getVirtualFile(Name, Source->getBufferSize(), 0);
+    Sources.overrideFileContents(Entry, Source, true);
+    assert(Entry != NULL);
+    return Sources.createFileID(Entry, SourceLocation(), SrcMgr::C_User);
+  }
+
+  FileID createOnDiskFile(StringRef Name, StringRef Content) {
+    if (!TemporaryDirectory.isValid()) {
+      std::string ErrorInfo;
+      TemporaryDirectory = llvm::sys::Path::GetTemporaryDirectory(&ErrorInfo);
+      assert(ErrorInfo.empty());
+    }
+    llvm::SmallString<1024> Path(TemporaryDirectory.str());
+    llvm::sys::path::append(Path, Name);
+    std::string ErrorInfo;
+    llvm::raw_fd_ostream OutStream(Path.c_str(),
+                                   ErrorInfo, llvm::raw_fd_ostream::F_Binary);
+    assert(ErrorInfo.empty());
+    OutStream << Content;
+    OutStream.close();
+    const FileEntry *File = Files.getFile(Path);
+    assert(File != NULL);
+    return Sources.createFileID(File, SourceLocation(), SrcMgr::C_User);
+  }
+
+  SourceLocation getLocation(FileID ID, unsigned Line, unsigned Column) {
+    SourceLocation Result = Sources.translateFileLineCol(
+        Sources.getFileEntryForID(ID), Line, Column);
+    assert(Result.isValid());
+    return Result;
+  }
+
+  std::string getRewrittenText(FileID ID) {
+    std::string Result;
+    llvm::raw_string_ostream OS(Result);
+    Rewrite.getEditBuffer(ID).write(OS);
+    return Result;
+  }
+
+  std::string getFileContentFromDisk(StringRef Name) {
+    llvm::SmallString<1024> Path(TemporaryDirectory.str());
+    llvm::sys::path::append(Path, Name);
+    // We need to read directly from the FileManager without relaying through
+    // a FileEntry, as otherwise we'd read through an already opened file
+    // descriptor, which might not see the changes made.
+    // FIXME: Figure out whether there is a way to get the SourceManger to
+    // reopen the file.
+    return Files.getBufferForFile(Path, NULL)->getBuffer();
+  }
+
+  DiagnosticsEngine Diagnostics;
+  TextDiagnosticPrinter DiagnosticPrinter;
+  FileManager Files;
+  SourceManager Sources;
+  LangOptions Options;
+  Rewriter Rewrite;
+
+  // Will be set once on disk files are generated. 
+  llvm::sys::Path TemporaryDirectory;
+};
+
+} // end namespace clang
+
+#endif