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RawPDB

RawPDB is a C++11 library that directly reads Microsoft Program DataBase PDB files. The code is extracted almost directly from the upcoming 2.0 release of <a href="https://liveplusplus.tech/">Live++</a>.

Design

RawPDB gives you direct access to the stream data contained in a PDB file. It does not attempt to offer abstractions for iterating symbols, translation units, contributions, etc.

Building a high-level abstraction over the provided low-level data is an ill-fated attempt that can never really be performant for everybody, because different tools like debuggers, hot-reload tools (e.g. <a href="https://liveplusplus.tech/">Live++</a>), profilers (e.g. <a href="https://superluminal.eu/">Superluminal</a>), need to perform different queries against the stored data.

We therefore believe the best solution is to offer direct access to the underlying data, with applications bringing that data into their own structures.

Goal

Eventually, we want RawPDB to become the de-facto replacement of <a href="https://docs.microsoft.com/en-us/visualstudio/debugger/debug-interface-access/debug-interface-access-sdk">Microsoft's DIA SDK</a> that most C++ developers (have to) use.

Features

• Fast - RawPDB works directly with memory-mapped data, so only the data from the streams you touch affect performance. It is orders of magnitudes faster than the DIA SDK, and faster than comparable LLVM code
• Scalable - RawPDB's API gives you access to individual streams that can all be read concurrently in a trivial fashion, since all returned data structures are immutable. There are no locks or waits anywhere inside the library
• Lightweight - RawPDB is small and compiles in roughly 1 second
• Allocation-friendly - RawPDB performs only a few allocations, and those can be overridden easily by changing the underlying macro
• No STL - RawPDB does not need any STL containers or algorithms
• No exceptions - RawPDB does not use exceptions
• No RTTI - RawPDB does not need RTTI or use class hierarchies
• High-quality code - RawPDB compiles clean under -Wall

Building

The code compiles clean under Visual Studio 2015, 2017, 2019, or 2022. A solution for Visual Studio 2019 is included.

Performance

Running the Symbols and Contributions examples on a 1GiB PDB yields the following output:

This is at least an order of magnitude faster than DIA, even though the example code is completely serial and uses std::vector, std::string, and std::sort, which are used for illustration purposes only.

When reading streams in a concurrent fashion, you will most likely be limited by the speed at which the OS can bring the data into your process.

Supported streams

RawPDB gives you access to the following PDB stream data:

• DBI stream data

  • Public symbols
  • Global symbols
  • Modules
  • Module symbols
  • Image sections
  • Info stream
  • Section contributions
  • Source files

• IPI stream data

At the moment, there is no support for C13 line information and the TPI type stream data, because Live++ does not make use of that information yet. However, we will gladly accept PRs, or implement support in the future.

Furthermore, PDBs linked using /DEBUG:FASTLINK are not supported. These PDBs do not contain much information, since private symbol information is distributed among object files and library files.

Documentation

If you are unfamiliar with the basic structure of a PDB file, the <a href="https://llvm.org/docs/PDB/index.html">LLVM documentation</a> serves as a good introduction.

Consult the example code to see how to read and parse the PDB streams.

Directory structure

• bin: contains final binary output files (.exe and .pdb)
• build: contains Visual Studio 2019 solution and project files
• lib: contains the RawPDB library output files (.lib and .pdb)
• src: contains the RawPDB source code, as well as example code
• temp: contains intermediate build artefacts

Examples

Symbols (<a href="https://github.com/MolecularMatters/raw_pdb/blob/main/src/Examples/ExampleSymbols.cpp">ExampleSymbols.cpp</a>)

A basic example that shows how to load and symbols from public, global, and module streams.

Contributions (<a href="https://github.com/MolecularMatters/raw_pdb/blob/main/src/Examples/ExampleContributions.cpp">ExampleContributions.cpp</a>)

A basic example that shows how to load contributions, sort them by size, and output the 20 largest ones along with the object file they originated from.

Function symbols (<a href="https://github.com/MolecularMatters/raw_pdb/blob/main/src/Examples/ExampleFunctionSymbols.cpp">ExampleFunctionSymbols.cpp</a>)

An example intended for profiler developers that shows how to enumerate all function symbols and retrieve or compute their code size.

Sponsoring or supporting RawPDB

We have chosen a very liberal license to let RawPDB be used in as many scenarios as possible, including commercial applications. If you would like to support its development, consider licensing <a href="https://liveplusplus.tech/">Live++</a> instead. Not only do you give something back, but get a great productivity enhancement on top!