[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, 35 insertions, 25 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index a0ed7cf8447..c8f35d1d3b6 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -151,10 +151,10 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
 
   // Compute the memory size required to load all sections to be loaded
   // and pass this information to the memory manager
-  if (MemMgr->needsToReserveAllocationSpace()) {
+  if (MemMgr.needsToReserveAllocationSpace()) {
     uint64_t CodeSize = 0, DataSizeRO = 0, DataSizeRW = 0;
     computeTotalAllocSize(Obj, CodeSize, DataSizeRO, DataSizeRW);
-    MemMgr->reserveAllocationSpace(CodeSize, DataSizeRO, DataSizeRW);
+    MemMgr.reserveAllocationSpace(CodeSize, DataSizeRO, DataSizeRW);
   }
 
   // Used sections from the object file
@@ -485,7 +485,7 @@ void RuntimeDyldImpl::emitCommonSymbols(const ObjectFile &Obj,
 
     // Skip common symbols already elsewhere.
     if (GlobalSymbolTable.count(Name) ||
-        MemMgr->getSymbolAddressInLogicalDylib(Name)) {
+        Resolver.findSymbolInLogicalDylib(Name)) {
       DEBUG(dbgs() << "\tSkipping already emitted common symbol '" << Name
                    << "'\n");
       continue;
@@ -502,8 +502,8 @@ void RuntimeDyldImpl::emitCommonSymbols(const ObjectFile &Obj,
 
   // Allocate memory for the section
   unsigned SectionID = Sections.size();
-  uint8_t *Addr = MemMgr->allocateDataSection(CommonSize, sizeof(void *),
-                                              SectionID, StringRef(), false);
+  uint8_t *Addr = MemMgr.allocateDataSection(CommonSize, sizeof(void *),
+                                             SectionID, StringRef(), false);
   if (!Addr)
     report_fatal_error("Unable to allocate memory for common symbols!");
   uint64_t Offset = 0;
@@ -577,10 +577,10 @@ unsigned RuntimeDyldImpl::emitSection(const ObjectFile &Obj,
   if (IsRequired) {
     Check(Section.getContents(data));
     Allocate = DataSize + PaddingSize + StubBufSize;
-    Addr = IsCode ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID,
-                                                Name)
-                  : MemMgr->allocateDataSection(Allocate, Alignment, SectionID,
-                                                Name, IsReadOnly);
+    Addr = IsCode ? MemMgr.allocateCodeSection(Allocate, Alignment, SectionID,
+                                               Name)
+                  : MemMgr.allocateDataSection(Allocate, Alignment, SectionID,
+                                               Name, IsReadOnly);
     if (!Addr)
       report_fatal_error("Unable to allocate section memory!");
 
@@ -787,9 +787,9 @@ void RuntimeDyldImpl::resolveExternalSymbols() {
       uint64_t Addr = 0;
       RTDyldSymbolTable::const_iterator Loc = GlobalSymbolTable.find(Name);
       if (Loc == GlobalSymbolTable.end()) {
-        // This is an external symbol, try to get its address from
-        // MemoryManager.
-        Addr = MemMgr->getSymbolAddress(Name.data());
+        // This is an external symbol, try to get its address from the symbol
+        // resolver.
+        Addr = Resolver.findSymbol(Name.data()).getAddress();
         // The call to getSymbolAddress may have caused additional modules to
         // be loaded, which may have added new entries to the
         // ExternalSymbolRelocations map.  Consquently, we need to update our
@@ -835,7 +835,12 @@ uint64_t RuntimeDyld::LoadedObjectInfo::getSectionLoadAddress(
   return 0;
 }
 
-RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) {
+void RuntimeDyld::MemoryManager::anchor() {}
+void RuntimeDyld::SymbolResolver::anchor() {}
+
+RuntimeDyld::RuntimeDyld(RuntimeDyld::MemoryManager &MemMgr,
+                         RuntimeDyld::SymbolResolver &Resolver)
+    : MemMgr(MemMgr), Resolver(Resolver) {
   // FIXME: There's a potential issue lurking here if a single instance of
   // RuntimeDyld is used to load multiple objects.  The current implementation
   // associates a single memory manager with a RuntimeDyld instance.  Even
@@ -843,7 +848,6 @@ RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) {
   // they share a single memory manager.  This can become a problem when page
   // permissions are applied.
   Dyld = nullptr;
-  MM = mm;
   ProcessAllSections = false;
   Checker = nullptr;
 }
@@ -851,27 +855,33 @@ RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) {
 RuntimeDyld::~RuntimeDyld() {}
 
 static std::unique_ptr<RuntimeDyldCOFF>
-createRuntimeDyldCOFF(Triple::ArchType Arch, RTDyldMemoryManager *MM,
+createRuntimeDyldCOFF(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MM,
+                      RuntimeDyld::SymbolResolver &Resolver,
                       bool ProcessAllSections, RuntimeDyldCheckerImpl *Checker) {
-  std::unique_ptr<RuntimeDyldCOFF> Dyld(RuntimeDyldCOFF::create(Arch, MM));
+  std::unique_ptr<RuntimeDyldCOFF> Dyld =
+    RuntimeDyldCOFF::create(Arch, MM, Resolver);
   Dyld->setProcessAllSections(ProcessAllSections);
   Dyld->setRuntimeDyldChecker(Checker);
   return Dyld;
 }
 
 static std::unique_ptr<RuntimeDyldELF>
-createRuntimeDyldELF(RTDyldMemoryManager *MM, bool ProcessAllSections,
-                     RuntimeDyldCheckerImpl *Checker) {
-  std::unique_ptr<RuntimeDyldELF> Dyld(new RuntimeDyldELF(MM));
+createRuntimeDyldELF(RuntimeDyld::MemoryManager &MM,
+                     RuntimeDyld::SymbolResolver &Resolver,
+                     bool ProcessAllSections, RuntimeDyldCheckerImpl *Checker) {
+  std::unique_ptr<RuntimeDyldELF> Dyld(new RuntimeDyldELF(MM, Resolver));
   Dyld->setProcessAllSections(ProcessAllSections);
   Dyld->setRuntimeDyldChecker(Checker);
   return Dyld;
 }
 
 static std::unique_ptr<RuntimeDyldMachO>
-createRuntimeDyldMachO(Triple::ArchType Arch, RTDyldMemoryManager *MM,
-                       bool ProcessAllSections, RuntimeDyldCheckerImpl *Checker) {
-  std::unique_ptr<RuntimeDyldMachO> Dyld(RuntimeDyldMachO::create(Arch, MM));
+createRuntimeDyldMachO(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MM,
+                       RuntimeDyld::SymbolResolver &Resolver,
+                       bool ProcessAllSections,
+                       RuntimeDyldCheckerImpl *Checker) {
+  std::unique_ptr<RuntimeDyldMachO> Dyld =
+    RuntimeDyldMachO::create(Arch, MM, Resolver);
   Dyld->setProcessAllSections(ProcessAllSections);
   Dyld->setRuntimeDyldChecker(Checker);
   return Dyld;
@@ -881,14 +891,14 @@ std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
 RuntimeDyld::loadObject(const ObjectFile &Obj) {
   if (!Dyld) {
     if (Obj.isELF())
-      Dyld = createRuntimeDyldELF(MM, ProcessAllSections, Checker);
+      Dyld = createRuntimeDyldELF(MemMgr, Resolver, ProcessAllSections, Checker);
     else if (Obj.isMachO())
       Dyld = createRuntimeDyldMachO(
-               static_cast<Triple::ArchType>(Obj.getArch()), MM,
+               static_cast<Triple::ArchType>(Obj.getArch()), MemMgr, Resolver,
                ProcessAllSections, Checker);
     else if (Obj.isCOFF())
       Dyld = createRuntimeDyldCOFF(
-               static_cast<Triple::ArchType>(Obj.getArch()), MM,
+               static_cast<Triple::ArchType>(Obj.getArch()), MemMgr, Resolver,
                ProcessAllSections, Checker);
     else
       report_fatal_error("Incompatible object format!");