[cfe-commits] r111983 - in /cfe/trunk: include/clang/Driver/CC1Options.td include/clang/Frontend/PreprocessorOutputOptions.h lib/Driver/Tools.cpp lib/Frontend/CompilerInvocation.cpp lib/Frontend/PrintPreprocessedOutput.cpp test/Frontend/Inputs/ t

[Chris Lattner]

On Sep 4, 2010, at 1:57 PM, Daniel Dunbar wrote:

>>> 
>>> +  // Dump the header include information, if enabled and we are past the
>>> +  // predefines buffer.
>>> +  if (DumpHeaderIncludes && HasProcessedPredefines &&
>>> +      Reason == PPCallbacks::EnterFile) {
>>> +    llvm::SmallString<256> Msg;
>>> +    llvm::raw_svector_ostream OS(Msg);
>>> +    for (unsigned i = 0; i != CurrentIncludeDepth; ++i)
>>> +      OS << '.';
>>> +    OS << ' ' << CurFilename << '\n';
>>> +    llvm::errs() << OS.str();
>> 
>> Why the temporary SmallString?
> 
> It writes on llvm::errs() directly, which has horrible buffering
> behavior. I didn't want to be flushing out one character at a time. A
> generally solution to this problem would make more sense, but there
> aren't so many places that output substantial text to stderr.

Alrighty.  If you wanted to simplify the code, you don't actually need raw_svector_ostream.  Msg.push_back and Msg.append should suffice for the operations you're doing.

-Chris