diff options
| -rw-r--r-- | include/llvm/Support/FormattedStream.h | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/include/llvm/Support/FormattedStream.h b/include/llvm/Support/FormattedStream.h index 9658979352..7260c3fba3 100644 --- a/include/llvm/Support/FormattedStream.h +++ b/include/llvm/Support/FormattedStream.h @@ -33,7 +33,8 @@ namespace llvm const static bool PRESERVE_STREAM = false; private: - /// TheStream - The real stream we output to. + /// TheStream - The real stream we output to. We set it to be + /// unbuffered, since we're already doing our own buffering. /// raw_ostream *TheStream; /// DeleteStream - Do we need to delete TheStream in the @@ -70,13 +71,27 @@ namespace llvm /// put into ErrorInfo, and the stream should be immediately /// destroyed; the string will be empty if no error occurred. /// + /// As a side effect, the given Stream is set to be Unbuffered. + /// This is because formatted_raw_ostream does its own buffering, + /// so it doesn't want another layer of buffering to be happening + /// underneath it. + /// /// \param Filename - The file to open. If this is "-" then the /// stream will use stdout instead. /// \param Binary - The file should be opened in binary mode on /// platforms that support this distinction. formatted_raw_ostream(raw_ostream &Stream, bool Delete = false) - : raw_ostream(), TheStream(&Stream), DeleteStream(Delete), Column(0) {} - explicit formatted_raw_ostream() + : raw_ostream(), TheStream(&Stream), DeleteStream(Delete), Column(0) { + // This formatted_raw_ostream inherits from raw_ostream, so it'll do its + // own buffering, and it doesn't need or want TheStream to do another + // layer of buffering underneath. Resize the buffer to what TheStream + // had been using, and tell TheStream not to do its own buffering. + TheStream->flush(); + if (size_t BufferSize = TheStream->GetNumBytesInBuffer()) + SetBufferSize(BufferSize); + TheStream->SetUnbuffered(); + } + explicit formatted_raw_ostream() : raw_ostream(), TheStream(0), DeleteStream(false), Column(0) {} ~formatted_raw_ostream() { @@ -87,6 +102,12 @@ namespace llvm void setStream(raw_ostream &Stream, bool Delete = false) { TheStream = &Stream; DeleteStream = Delete; + + // Avoid double-buffering, as above. + TheStream->flush(); + if (size_t BufferSize = TheStream->GetNumBytesInBuffer()) + SetBufferSize(BufferSize); + TheStream->SetUnbuffered(); } /// PadToColumn - Align the output to some column number. |