The efficiency of debug info in LLVM and Clang improved dramatically this year. This talk is about what it took to get here and what work remains.
We'll talk about how Metadata was redesigned to make the debug info IR memory-efficient (with a human-readable assembly syntax). We'll go into the implications for other Metadata graphs, and what a more expressive Metadata future could look like. We'll also include an overview of what's left to scale debug info for LTO.
We'll also talk about Clang's new module debugging feature, which reduces the size of debug info on disk, improves compile time, and makes full type information available to debuggers. We'll highlight how Clang-based debuggers like LLDB can use module debug information to enhance expression evaluation.
