llvm-project/llvm/examples/Kaleidoscope/Orc/lazy_codegen
Lang Hames 633fe146e9 [MCJIT][Orc] Refactor RTDyldMemoryManager, weave RuntimeDyld::SymbolInfo through
MCJIT.

This patch decouples the two responsibilities of the RTDyldMemoryManager class,
memory management and symbol resolution, into two new classes:
RuntimeDyld::MemoryManager and RuntimeDyld::SymbolResolver.

The symbol resolution interface is modified slightly, from:

  uint64_t getSymbolAddress(const std::string &Name);

to:

  RuntimeDyld::SymbolInfo findSymbol(const std::string &Name);

The latter passes symbol flags along with symbol addresses, allowing RuntimeDyld
and others to reason about non-strong/non-exported symbols.


The memory management interface removes the following method:

  void notifyObjectLoaded(ExecutionEngine *EE,
                          const object::ObjectFile &) {}

as it is not related to memory management. (Note: Backwards compatibility *is*
maintained for this method in MCJIT and OrcMCJITReplacement, see below).


The RTDyldMemoryManager class remains in-tree for backwards compatibility.
It inherits directly from RuntimeDyld::SymbolResolver, and indirectly from
RuntimeDyld::MemoryManager via the new MCJITMemoryManager class, which
just subclasses RuntimeDyld::MemoryManager and reintroduces the
notifyObjectLoaded method for backwards compatibility).

The EngineBuilder class retains the existing method:

  EngineBuilder&
  setMCJITMemoryManager(std::unique_ptr<RTDyldMemoryManager> mcjmm);

and includes two new methods:

  EngineBuilder&
  setMemoryManager(std::unique_ptr<MCJITMemoryManager> MM);

  EngineBuilder&
  setSymbolResolver(std::unique_ptr<RuntimeDyld::SymbolResolver> SR);

Clients should use EITHER:

A single call to setMCJITMemoryManager with an RTDyldMemoryManager.

OR (exclusive)

One call each to each of setMemoryManager and setSymbolResolver.

This patch should be fully compatible with existing uses of RTDyldMemoryManager.
If it is not it should be considered a bug, and the patch either fixed or
reverted.

If clients find the new API to be an improvement the goal will be to deprecate
and eventually remove the RTDyldMemoryManager class in favor of the new classes.

llvm-svn: 233509
2015-03-30 03:37:06 +00:00
..
CMakeLists.txt [CMake] Kaleidoscope-Orc: Update libdeps. 2015-02-08 11:15:08 +00:00
Makefile [Orc][Kaleidoscope] Fix the orc/kaleidoscope tutorials on linux. 2015-02-20 02:03:30 +00:00
README.txt
toy.cpp [MCJIT][Orc] Refactor RTDyldMemoryManager, weave RuntimeDyld::SymbolInfo through 2015-03-30 03:37:06 +00:00

README.txt

//===----------------------------------------------------------------------===/
//                 Kaleidoscope with Orc - Initial Version
//===----------------------------------------------------------------------===//

This version of Kaleidoscope with Orc demonstrates lazy code-generation.
Unlike the first Kaleidoscope-Orc tutorial, where code-gen was performed as soon
as modules were added to the JIT, this tutorial adds a LazyEmittingLayer to defer
code-generation until modules are actually referenced. All IR-generation is still
performed up-front.

This directory contain a Makefile that allow the code to be built in a
standalone manner, independent of the larger LLVM build infrastructure. To build
the program you will need to have 'clang++' and 'llvm-config' in your path.