From 434b54846dbb03d3f68f27ea8b7ce8baecae4a45 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Wed, 19 May 2010 01:21:34 +0000 Subject: [PATCH] Add a comment explaining why this code uses Append mode. llvm-svn: 104095 --- lib/Support/Timer.cpp | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/Support/Timer.cpp b/lib/Support/Timer.cpp index 481f6ba5086..784b77cf591 100644 --- a/lib/Support/Timer.cpp +++ b/lib/Support/Timer.cpp @@ -61,6 +61,10 @@ raw_ostream *llvm::CreateInfoOutputFile() { if (OutputFilename == "-") return new raw_fd_ostream(1, false); // stdout. + // Append mode is used because the info output file is opened and closed + // each time -stats or -time-passes wants to print output to it. To + // compensate for this, the test-suite Makefiles have code to delete the + // info output file before running commands which write to it. std::string Error; raw_ostream *Result = new raw_fd_ostream(OutputFilename.c_str(), Error, raw_fd_ostream::F_Append);