1 =========================================================================== 2 Building a JIT: Extreme Laziness - Using Compile Callbacks to JIT from ASTs 3 =========================================================================== 4 5 .. contents:: 6 :local: 7 8 **This tutorial is under active development. It is incomplete and details may 9 change frequently.** Nonetheless we invite you to try it out as it stands, and 10 we welcome any feedback. 11 12 Chapter 4 Introduction 13 ====================== 14 15 Welcome to Chapter 4 of the "Building an ORC-based JIT in LLVM" tutorial. This 16 chapter introduces the Compile Callbacks and Indirect Stubs APIs and shows how 17 they can be used to replace the CompileOnDemand layer from 18 `Chapter 3 <BuildingAJIT3.html>`_ with a custom lazy-JITing scheme that JITs 19 directly from Kaleidoscope ASTs. 20 21 **To be done:** 22 23 **(1) Describe the drawbacks of JITing from IR (have to compile to IR first, 24 which reduces the benefits of laziness).** 25 26 **(2) Describe CompileCallbackManagers and IndirectStubManagers in detail.** 27 28 **(3) Run through the implementation of addFunctionAST.** 29 30 Full Code Listing 31 ================= 32 33 Here is the complete code listing for our running example that JITs lazily from 34 Kaleidoscope ASTS. To build this example, use: 35 36 .. code-block:: bash 37 38 # Compile 39 clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core orcjit native` -O3 -o toy 40 # Run 41 ./toy 42 43 Here is the code: 44 45 .. literalinclude:: ../../examples/Kaleidoscope/BuildingAJIT/Chapter4/KaleidoscopeJIT.h 46 :language: c++ 47 48 `Next: Remote-JITing -- Process-isolation and laziness-at-a-distance <BuildingAJIT5.html>`_ 49
