[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

1 files changed, 28 insertions, 9 deletions

diff --git a/llvm/lib/ExecutionEngine/ExecutionEngine.cpp b/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
index c586ba7..238663a 100644
--- a/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -18,6 +18,7 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ExecutionEngine/GenericValue.h"
 #include "llvm/ExecutionEngine/JITEventListener.h"
+#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
@@ -45,11 +46,13 @@ STATISTIC(NumGlobals  , "Number of global vars initialized");
 
 ExecutionEngine *(*ExecutionEngine::MCJITCtor)(
     std::unique_ptr<Module> M, std::string *ErrorStr,
-    std::unique_ptr<RTDyldMemoryManager> MCJMM,
+    std::shared_ptr<MCJITMemoryManager> MemMgr,
+    std::shared_ptr<RuntimeDyld::SymbolResolver> Resolver,
     std::unique_ptr<TargetMachine> TM) = nullptr;
 
 ExecutionEngine *(*ExecutionEngine::OrcMCJITReplacementCtor)(
-  std::string *ErrorStr, std::unique_ptr<RTDyldMemoryManager> OrcJMM,
+  std::string *ErrorStr, std::shared_ptr<MCJITMemoryManager> MemMgr,
+  std::shared_ptr<RuntimeDyld::SymbolResolver> Resolver,
   std::unique_ptr<TargetMachine> TM) = nullptr;
 
 ExecutionEngine *(*ExecutionEngine::InterpCtor)(std::unique_ptr<Module> M,
@@ -404,8 +407,9 @@ EngineBuilder::EngineBuilder() : EngineBuilder(nullptr) {}
 
 EngineBuilder::EngineBuilder(std::unique_ptr<Module> M)
     : M(std::move(M)), WhichEngine(EngineKind::Either), ErrorStr(nullptr),
-      OptLevel(CodeGenOpt::Default), MCJMM(nullptr), RelocModel(Reloc::Default),
-      CMModel(CodeModel::JITDefault), UseOrcMCJITReplacement(false) {
+      OptLevel(CodeGenOpt::Default), MemMgr(nullptr), Resolver(nullptr),
+      RelocModel(Reloc::Default), CMModel(CodeModel::JITDefault),
+      UseOrcMCJITReplacement(false) {
 // IR module verification is enabled by default in debug builds, and disabled
 // by default in release builds.
 #ifndef NDEBUG
@@ -419,7 +423,21 @@ EngineBuilder::~EngineBuilder() = default;
 
 EngineBuilder &EngineBuilder::setMCJITMemoryManager(
                                    std::unique_ptr<RTDyldMemoryManager> mcjmm) {
-  MCJMM = std::move(mcjmm);
+  auto SharedMM = std::shared_ptr<RTDyldMemoryManager>(std::move(mcjmm));
+  MemMgr = SharedMM;
+  Resolver = SharedMM;
+  return *this;
+}
+
+EngineBuilder&
+EngineBuilder::setMemoryManager(std::unique_ptr<MCJITMemoryManager> MM) {
+  MemMgr = std::shared_ptr<MCJITMemoryManager>(std::move(MM));
+  return *this;
+}
+
+EngineBuilder&
+EngineBuilder::setSymbolResolver(std::unique_ptr<RuntimeDyld::SymbolResolver> SR) {
+  Resolver = std::shared_ptr<RuntimeDyld::SymbolResolver>(std::move(SR));
   return *this;
 }
 
@@ -434,7 +452,7 @@ ExecutionEngine *EngineBuilder::create(TargetMachine *TM) {
   // If the user specified a memory manager but didn't specify which engine to
   // create, we assume they only want the JIT, and we fail if they only want
   // the interpreter.
-  if (MCJMM) {
+  if (MemMgr) {
     if (WhichEngine & EngineKind::JIT)
       WhichEngine = EngineKind::JIT;
     else {
@@ -456,12 +474,13 @@ ExecutionEngine *EngineBuilder::create(TargetMachine *TM) {
 
     ExecutionEngine *EE = nullptr;
     if (ExecutionEngine::OrcMCJITReplacementCtor && UseOrcMCJITReplacement) {
-      EE = ExecutionEngine::OrcMCJITReplacementCtor(ErrorStr, std::move(MCJMM),
+      EE = ExecutionEngine::OrcMCJITReplacementCtor(ErrorStr, std::move(MemMgr),
+                                                    std::move(Resolver),
                                                     std::move(TheTM));
       EE->addModule(std::move(M));
     } else if (ExecutionEngine::MCJITCtor)
-      EE = ExecutionEngine::MCJITCtor(std::move(M), ErrorStr, std::move(MCJMM),
-                                      std::move(TheTM));
+      EE = ExecutionEngine::MCJITCtor(std::move(M), ErrorStr, std::move(MemMgr),
+                                      std::move(Resolver), std::move(TheTM));
 
     if (EE) {
       EE->setVerifyModules(VerifyModules);