[PATCH] D25356: Define PDBFileBuilder::addStream to add stream.

[Zachary Turner via llvm-commits]

Ok I think I understand this more now.  I don't think we should expose this
method, because for one thing just writing the data to this stream is not
sufficient to link it up to the PDB.  It has to be referenced from the DBI
stream, and is one of the "optional debug streams" that comes at the end of
the DBI stream.

So instead, how about adding something to DbiStreamBuilder.  It could be
called

void setDbgStreamBytes(DbgHeaderType Type, ArrayRef<uint8_t> Bytes);

Then you call this as

setDbgStreamBytes(DbgHeaderType::SectionHdr, SectionHeaderBytes);

Then, in DbiStreamBuilder::commit(), it does the right thing for each
optional debug info stream that has data (i.e. goes through the MsfLayout
to create a new indexed stream, etc).  Also in DbiStreamBuilder::commit()
you will need to write the optional debug info data at the very end of the
dbi stream.

On Thu, Oct 6, 2016 at 8:52 PM Zachary Turner <zturner at google.com> wrote:

> Ahh, i see the other patch now.
>
> Wouldn't it be possible to create SectionHeaderStreamBuilder with a well
> defined interface, then call MsfBuilder.getSectionHeaderBuilder()?
> On Thu, Oct 6, 2016 at 8:50 PM Zachary Turner <zturner at google.com> wrote:
>
> What will this be used for? I tried to approach this with the mindset of
> making it impossible to construct invalid pdb data, because your only
> interface to writing is via a closed api. Allowing writing of arbitrary
> bytes breaks this. What use did you have in mind?
>
>
> On Thu, Oct 6, 2016 at 8:25 PM Rui Ueyama <ruiu at google.com> wrote:
>
> ruiu created this revision.
> ruiu added a reviewer: zturner.
> ruiu added a subscriber: llvm-commits.
>
> Previously, there is no way to create a stream other than
> pre-defined special stream such as DBI or IPI. This patch
> adds a new method, addStream, to add a stream of arbitrary
> bytes to a PDB file. The new function takes a byte array
> and returns the index of the new stream.
>
>
> https://reviews.llvm.org/D25356
>
> Files:
>   include/llvm/DebugInfo/PDB/Raw/DbiStreamBuilder.h
>   include/llvm/DebugInfo/PDB/Raw/PDBFileBuilder.h
>   lib/DebugInfo/PDB/Raw/DbiStreamBuilder.cpp
>   lib/DebugInfo/PDB/Raw/PDBFileBuilder.cpp
>
>
> Index: lib/DebugInfo/PDB/Raw/PDBFileBuilder.cpp
> ===================================================================
> --- lib/DebugInfo/PDB/Raw/PDBFileBuilder.cpp
> +++ lib/DebugInfo/PDB/Raw/PDBFileBuilder.cpp
> @@ -66,6 +66,16 @@
>    return *Ipi;
>  }
>
> +Expected<uint32_t> PDBFileBuilder::addStream(ArrayRef<uint8_t> Data) {
> +  auto ExpectedIndex = Msf->addStream(Data.size());
> +  if (!ExpectedIndex)
> +    return ExpectedIndex.takeError();
> +  uint32_t Index = std::move(*ExpectedIndex);
> +
> +  Streams.emplace_back(Data, Index);
> +  return *ExpectedIndex;
> +}
> +
>  Expected<msf::MSFLayout> PDBFileBuilder::finalizeMsfLayout() const {
>    if (Info) {
>      if (auto EC = Info->finalizeMsfLayout())
> @@ -189,5 +199,14 @@
>        return EC;
>    }
>
> +  for (auto &Pair : Streams) {
> +    ArrayRef<uint8_t> Data = Pair.first;
> +    uint32_t Idx = Pair.second;
> +    auto Stream = WritableMappedBlockStream::createIndexedStream(Layout,
> Buffer, Idx);
> +    StreamWriter Writer(*Stream);
> +    if (auto EC = Writer.writeArray(Data))
> +      return EC;
> +  }
> +
>    return Buffer.commit();
>  }
> Index: lib/DebugInfo/PDB/Raw/DbiStreamBuilder.cpp
> ===================================================================
> --- lib/DebugInfo/PDB/Raw/DbiStreamBuilder.cpp
> +++ lib/DebugInfo/PDB/Raw/DbiStreamBuilder.cpp
> @@ -44,6 +44,10 @@
>
>  void DbiStreamBuilder::setMachineType(PDB_Machine M) { MachineType = M; }
>
> +void DbiStreamBuilder::setDebugStreamIndex(DbgHeaderType Type, uint32_t
> Index) {
> +  DbgStreams[(int)Type] = Index;
> +}
> +
>  uint32_t DbiStreamBuilder::calculateSerializedLength() const {
>    // For now we only support serializing the header.
>    return sizeof(DbiStreamHeader) + calculateFileInfoSubstreamSize() +
> Index: include/llvm/DebugInfo/PDB/Raw/PDBFileBuilder.h
> ===================================================================
> --- include/llvm/DebugInfo/PDB/Raw/PDBFileBuilder.h
> +++ include/llvm/DebugInfo/PDB/Raw/PDBFileBuilder.h
> @@ -44,6 +44,9 @@
>    TpiStreamBuilder &getTpiBuilder();
>    TpiStreamBuilder &getIpiBuilder();
>
> +  // Add given bytes as a new stream. Returns the stream index.
> +  Expected<uint32_t> addStream(ArrayRef<uint8_t> Data);
> +
>    Expected<std::unique_ptr<PDBFile>>
>    build(std::unique_ptr<msf::WritableStream> PdbFileBuffer);
>
> @@ -59,6 +62,7 @@
>    std::unique_ptr<DbiStreamBuilder> Dbi;
>    std::unique_ptr<TpiStreamBuilder> Tpi;
>    std::unique_ptr<TpiStreamBuilder> Ipi;
> +  std::vector<std::pair<ArrayRef<uint8_t>, uint32_t>> Streams;
>  };
>  }
>  }
> Index: include/llvm/DebugInfo/PDB/Raw/DbiStreamBuilder.h
> ===================================================================
> --- include/llvm/DebugInfo/PDB/Raw/DbiStreamBuilder.h
> +++ include/llvm/DebugInfo/PDB/Raw/DbiStreamBuilder.h
> @@ -44,6 +44,7 @@
>    void setPdbDllRbld(uint16_t R);
>    void setFlags(uint16_t F);
>    void setMachineType(PDB_Machine M);
> +  void setDebugStreamIndex(DbgHeaderType Type, uint32_t Index);
>
>    uint32_t calculateSerializedLength() const;
>
>
>
>
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