J9AheadOfTimeCompile.cpp

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#include "codegen/AheadOfTimeCompile.hpp"
#include "env/FrontEnd.hpp"
#include "codegen/Instruction.hpp"
#include "compile/AOTClassInfo.hpp"
#include "compile/Compilation.hpp"
#include "compile/ResolvedMethod.hpp"
#include "compile/VirtualGuard.hpp"
#include "env/CHTable.hpp"
#include "env/ClassLoaderTable.hpp"
#include "env/CompilerEnv.hpp"
#include "env/SharedCache.hpp"
#include "env/jittypes.h"
#include "env/VMJ9.h"
#include "il/Node.hpp"
#include "il/Node_inlines.hpp"
#include "il/SymbolReference.hpp"
#include "ras/DebugCounter.hpp"
#include "runtime/CodeCacheConfig.hpp"
#include "runtime/CodeCacheManager.hpp"
#include "runtime/RelocationRuntime.hpp"
#include "runtime/RelocationRecord.hpp"
#include "runtime/SymbolValidationManager.hpp"

#define NON_HELPER   0x00

void J9::X86::AheadOfTimeCompile::processRelocations()
   {
   TR::Compilation *comp = _cg->comp();

   // calculate the amount of memory needed to hold the relocation data
   TR_J9VMBase *fej9 = (TR_J9VMBase *)(_cg->fe());

   if (comp->target().is64Bit()
       && TR::CodeCacheManager::instance()->codeCacheConfig().needsMethodTrampolines()
       && _cg->getPicSlotCount())
      {
      _cg->addExternalRelocation(new (_cg->trHeapMemory()) TR::ExternalRelocation(NULL,
                                                                                 (uint8_t *)(uintptr_t)_cg->getPicSlotCount(),
                                                                                 TR_PicTrampolines, _cg),
                            __FILE__,
                            __LINE__,
                            NULL);
      }


   for (auto aotIterator = _cg->getExternalRelocationList().begin(); aotIterator != _cg->getExternalRelocationList().end(); ++aotIterator)
	  (*aotIterator)->addExternalRelocation(_cg);

   TR::IteratedExternalRelocation *r;
   for (r = self()->getAOTRelocationTargets().getFirst();
        r != NULL;
        r = r->getNext())
      {
      self()->addToSizeOfAOTRelocations(r->getSizeOfRelocationData());
      }

   // now allocate the memory  size of all iterated relocations + the header (total length field)

   // Note that when using the SymbolValidationManager, the well-known classes
   // must be checked even if no explicit records were generated, since they
   // might be responsible for the lack of records.
   bool useSVM = comp->getOption(TR_UseSymbolValidationManager);
   if (self()->getSizeOfAOTRelocations() != 0 || useSVM)
      {
      // It would be more straightforward to put the well-known classes offset
      // in the AOT method header, but that would use space for AOT bodies that
      // don't use the SVM. TODO: Move it once SVM takes over?
      int wellKnownClassesOffsetSize = useSVM ? SIZEPOINTER : 0;
      uintptr_t reloBufferSize =
         self()->getSizeOfAOTRelocations() + SIZEPOINTER + wellKnownClassesOffsetSize;
      uint8_t *relocationDataCursor = self()->setRelocationData(
         fej9->allocateRelocationData(comp, reloBufferSize));
      // set up the size for the region
      *(uintptr_t *)relocationDataCursor = reloBufferSize;
      relocationDataCursor += SIZEPOINTER;

      if (useSVM)
         {
         TR::SymbolValidationManager *svm = comp->getSymbolValidationManager();
         void *offsets = const_cast<void *>(svm->wellKnownClassChainOffsets());
         uintptr_t *wkcOffsetAddr = (uintptr_t *)relocationDataCursor;
         *wkcOffsetAddr = self()->offsetInSharedCacheFromPointer(fej9->sharedCache(), offsets);
#if defined(J9VM_OPT_JITSERVER)
         self()->addWellKnownClassesSerializationRecord(svm->aotCacheWellKnownClassesRecord(), wkcOffsetAddr);
#endif /* defined(J9VM_OPT_JITSERVER) */
         relocationDataCursor += SIZEPOINTER;
         }

      // set up pointers for each iterated relocation and initialize header
      TR::IteratedExternalRelocation *s;
      for (s = self()->getAOTRelocationTargets().getFirst();
           s != 0;
           s = s->getNext())
         {
         s->setRelocationData(relocationDataCursor);
         s->initializeRelocation(_cg);
         relocationDataCursor += s->getSizeOfRelocationData();
         }
      }
   }

bool
J9::X86::AheadOfTimeCompile::initializePlatformSpecificAOTRelocationHeader(TR::IteratedExternalRelocation *relocation,
                                                                           TR_RelocationTarget *reloTarget,
                                                                           TR_RelocationRecord *reloRecord,
                                                                           uint8_t targetKind)
   {
   bool platformSpecificReloInitialized = true;

   switch (targetKind)
      {
      case TR_PicTrampolines:
         {
         TR_RelocationRecordPicTrampolines *ptRecord = reinterpret_cast<TR_RelocationRecordPicTrampolines *>(reloRecord);

         TR_ASSERT(self()->comp()->target().is64Bit(), "TR_PicTrampolines not supported on 32-bit");
         uint32_t numTrampolines = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(relocation->getTargetAddress()));
         ptRecord->setNumTrampolines(reloTarget, numTrampolines);
         }
        break;

      default:
         platformSpecificReloInitialized = false;
      }

   return platformSpecificReloInitialized;
   }