Lang Hames da62155c11 [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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233509 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-30 03:37:06 +00:00
..

//===----------------------------------------------------------------------===/
//                 Kaleidoscope with Orc - Lazy IRGen Version
//===----------------------------------------------------------------------===//

This version of Kaleidoscope with Orc demonstrates lazy IR-generation.
Building on the lazy-codegen version of the tutorial, this version reduces the
amount of up-front work that must be done by lazily IRgen'ing ASTs. When a
function definition is entered, its AST is added to a map of available
definitions. No IRGen is performed at this point and nothing is added to the JIT.
When attempting to resolve symbol addresses, the lambda in
KaleidoscopeJIT::getSymbolAddress will scan the AST map and generate IR on the
fly.

This directory contains a Makefile that allows 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.