- added unittests for the raw_fd_stream output case.
- the `BitstreamWriter` ctor was confusing, the relationship between the buffer and the file stream wasn't clear and in fact there was a potential bug in `BitcodeWriter` in the mach-o case, because that code assumed in-buffer only serialization. The incremental flushing behavior of flushing at end of block boundaries was an implementation detail that meant serializers not using blocks (for example) would need to know to check the buffer and flush. The bug was latent - in the sense that, today, because the stream being passed was not a `raw_fd_stream`, incremental buffering never kicked in.
The new design moves the responsibility of flushing to the `BitstreamWriter`, and makes it work with any `raw_ostream` (but incrementally flush only in the `raw_fd_stream` case). If the `raw_ostream` is over a buffer - i.e. a `raw_svector_stream` - then it's equivalent to today's buffer case. For all other `raw_ostream` cases, buffering is an implementation detail. In all cases, the buffer is flushed (well, in the buffer case, that's a moot statement).
This simplifies the state and state transitions the user has to track: you have a raw_ostream -> BitstreamWrite in it -> destroy the writer => the bitstream is completely written in your raw_ostream. The "buffer" case and the "raw_fd_stream" case become optimizations rather than imposing state transition concerns to the user.
C++23 will make these conversions ambiguous - so fix them to make the
codebase forward-compatible with C++23 (& a follow-up change I've made
will make this ambiguous/invalid even in <C++23 so we don't regress
this & it generally improves the code anyway)
This moves Bitcode/Bitstream*, Bitcode/BitCodes.h to Bitstream/.
This is needed to avoid a circular dependency when using the bitstream
code for parsing optimization remarks.
Since Bitcode uses Core for the IR part:
libLLVMRemarks -> Bitcode -> Core
and Core uses libLLVMRemarks to generate remarks (see
IR/RemarkStreamer.cpp):
Core -> libLLVMRemarks
we need to separate the Bitstream and Bitcode part.
For clang-doc, it seems that it doesn't need the whole bitcode layer, so
I updated the CMake to only use the bitstream part.
Differential Revision: https://reviews.llvm.org/D63899
llvm-svn: 365091
