Adds a method overwriteChangedFiles to the Rewriter. This is implemented by
first writing the changed files to a temporary location and then overwriting
the original files atomically.
Also adds a RewriterTestContext to aid unit testing rewrting logic in general.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@157260 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Rewrite/Rewriter.cpp b/lib/Rewrite/Rewriter.cpp
index 43fb01b..a2d03a1 100644
--- a/lib/Rewrite/Rewriter.cpp
+++ b/lib/Rewrite/Rewriter.cpp
@@ -15,9 +15,12 @@
#include "clang/Rewrite/Rewriter.h"
#include "clang/AST/Stmt.h"
#include "clang/AST/Decl.h"
-#include "clang/Lex/Lexer.h"
+#include "clang/Basic/DiagnosticIDs.h"
+#include "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/Lexer.h"
#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/FileSystem.h"
using namespace clang;
raw_ostream &RewriteBuffer::write(raw_ostream &os) const {
@@ -412,3 +415,68 @@
return false;
}
+
+// A wrapper for a file stream that atomically overwrites the target.
+//
+// Creates a file output stream for a temporary file in the constructor,
+// which is later accessible via getStream() if ok() return true.
+// Flushes the stream and moves the temporary file to the target location
+// in the destructor.
+class AtomicallyMovedFile {
+public:
+ AtomicallyMovedFile(DiagnosticsEngine &Diagnostics, StringRef Filename,
+ bool &AllWritten)
+ : Diagnostics(Diagnostics), Filename(Filename), AllWritten(AllWritten) {
+ TempFilename = Filename;
+ TempFilename += "-%%%%%%%%";
+ int FD;
+ if (llvm::sys::fs::unique_file(TempFilename.str(), FD, TempFilename,
+ /*makeAbsolute=*/true, 0664)) {
+ AllWritten = false;
+ Diagnostics.Report(clang::diag::err_unable_to_make_temp)
+ << TempFilename;
+ } else {
+ FileStream.reset(new llvm::raw_fd_ostream(FD, /*shouldClose=*/true));
+ }
+ }
+
+ ~AtomicallyMovedFile() {
+ if (!ok()) return;
+
+ FileStream->flush();
+ if (llvm::error_code ec =
+ llvm::sys::fs::rename(TempFilename.str(), Filename)) {
+ AllWritten = false;
+ Diagnostics.Report(clang::diag::err_unable_to_rename_temp)
+ << TempFilename << Filename << ec.message();
+ bool existed;
+ // If the remove fails, there's not a lot we can do - this is already an
+ // error.
+ llvm::sys::fs::remove(TempFilename.str(), existed);
+ }
+ }
+
+ bool ok() { return FileStream; }
+ llvm::raw_ostream &getStream() { return *FileStream; }
+
+private:
+ DiagnosticsEngine &Diagnostics;
+ StringRef Filename;
+ SmallString<128> TempFilename;
+ OwningPtr<llvm::raw_fd_ostream> FileStream;
+ bool &AllWritten;
+};
+
+bool Rewriter::overwriteChangedFiles() {
+ bool AllWritten = true;
+ for (buffer_iterator I = buffer_begin(), E = buffer_end(); I != E; ++I) {
+ const FileEntry *Entry =
+ getSourceMgr().getFileEntryForID(I->first);
+ AtomicallyMovedFile File(getSourceMgr().getDiagnostics(), Entry->getName(),
+ AllWritten);
+ if (File.ok()) {
+ I->second.write(File.getStream());
+ }
+ }
+ return !AllWritten;
+}