corda/src/bootimage.cpp

/* Copyright (c) 2008, Avian Contributors

   Permission to use, copy, modify, and/or distribute this software
   for any purpose with or without fee is hereby granted, provided
   that the above copyright notice and this permission notice appear
   in all copies.

   There is NO WARRANTY for this software.  See license.txt for
   details. */

#include "bootimage.h"
#include "heapwalk.h"
#include "common.h"
#include "machine.h"
#include "util.h"
#include "assembler.h"

// since we aren't linking against libstdc++, we must implement this
// ourselves:
extern "C" void __cxa_pure_virtual(void) { abort(); }

using namespace vm;

namespace {

bool
endsWith(const char* suffix, const char* s, unsigned length)
{
  unsigned suffixLength = strlen(suffix);
  return length >= suffixLength
    and memcmp(suffix, s + (length - suffixLength), suffixLength) == 0;
}

unsigned
codeMapSize(unsigned codeSize)
{
  return ceiling(codeSize, BitsPerWord) * BytesPerWord;
}

object
makeCodeImage(Thread* t, BootImage* image, uint8_t* code, unsigned capacity)
{
  unsigned size;
  t->m->processor->compileThunks(t, image, code, &size, capacity);

  object objectTable = makeHashMap(t, 0, 0);
  PROTECT(t, objectTable);

  Zone zone(t->m->system, t->m->heap, 64 * 1024);

  for (Finder::Iterator it(t->m->finder); it.hasMore();) {
    unsigned nameSize;
    const char* name = it.next(&nameSize);

    if (endsWith(".class", name, nameSize)) {
      object c = resolveClass
        (t, makeByteArray(t, "%*s", nameSize - 5, name));
      PROTECT(t, c);
      
      for (unsigned i = 0; i < arrayLength(t, classMethodTable(t, c)); ++i) {
        object method = arrayBody(t, classMethodTable(t, c), i);
        if (methodCode(t, method)) {
          t->m->processor->compileMethod
            (t, &zone, code, &size, capacity, objectTable, method);
        }
      }
    }
  }

  image->codeSize = size;

  return objectTable;
}

unsigned
heapMapSize(unsigned heapSize)
{
  return ceiling(heapSize, BitsPerWord * 8) * BytesPerWord;
}

unsigned
objectSize(Thread* t, object o)
{
  assert(t, not objectExtended(t, o));
  return baseSize(t, o, objectClass(t, o));
}

void
visitRoots(Machine* m, BootImage* image, HeapWalker* w)
{
  image->loader = w->visitRoot(m->loader);
  image->stringMap = w->visitRoot(m->stringMap);
  image->types = w->visitRoot(m->types);

  m->processor->visitRoots(image, w);
}

HeapWalker*
makeHeapImage(Thread* t, BootImage* image, uintptr_t* heap, uintptr_t* map,
              unsigned capacity)
{
  class Visitor: public HeapVisitor {
   public:
    Visitor(Thread* t, uintptr_t* heap, uintptr_t* map, unsigned capacity):
      t(t), currentObject(0), currentOffset(0), heap(heap), map(map),
      position(0), capacity(capacity)
    { }

    void visit(object p, unsigned number) {
      if (currentObject) {
        markBit(map, (currentObject - heap) + currentOffset);
        currentObject[currentOffset] = number;
      }

      currentObject = reinterpret_cast<uintptr_t*>(p);
    }

    virtual void root() {
      currentObject = 0;
    }

    virtual unsigned visitNew(object p) {
      if (p) {
        unsigned size = objectSize(t, p);
        assert(t, position + size < capacity);

        memcpy(heap + position, p, size * BytesPerWord);

        unsigned number = position + 1;
        position += size;

        visit(p, number);

        return number;
      } else {
        return 0;
      }
    }

    virtual void visitOld(object, unsigned number) {
      visit(0, number);
    }

    virtual void push(unsigned offset) {
      currentOffset = offset;
    }

    virtual void pop() {
      currentObject = 0;
    }

    Thread* t;
    uintptr_t* currentObject;
    unsigned currentOffset;
    uintptr_t* heap;
    uintptr_t* map;
    unsigned position;
    unsigned capacity;
  } visitor(t, heap, map, capacity / BytesPerWord);

  HeapWalker* w = makeHeapWalker(t, &visitor);
  visitRoots(t->m, image, w);
  
  image->heapSize = visitor.position * BytesPerWord;

  return w;
}

void
updateCodeTable(Thread* t, object codeTable, uint8_t* code, uintptr_t* codeMap,
                HeapMap* heapTable)
{
  intptr_t i = 0;
  for (HashMapIterator it(t, codeTable); it.hasMore(); ++i) {
    object mapEntry = it.next();
    intptr_t target = heapTable->find(tripleFirst(t, mapEntry));
    assert(t, target >= 0);

    for (object fixup = tripleSecond(t, mapEntry);
         fixup;
         fixup = pairSecond(t, fixup))
    {
      OfferPromise* p = static_cast<OfferPromise*>
        (pointerValue(t, pairFirst(t, fixup)));
      assert(t, p->offset);

      memcpy(p->offset, &target, BytesPerWord);
      markBit(codeMap, reinterpret_cast<intptr_t>(p->offset)
              - reinterpret_cast<intptr_t>(code));
    }
  }
}

unsigned
offset(object a, uintptr_t* b)
{
  return reinterpret_cast<uintptr_t>(b) - reinterpret_cast<uintptr_t>(a);
}

void
writeBootImage(Thread* t, FILE* out)
{
  BootImage image;

  const unsigned CodeCapacity = 32 * 1024 * 1024;
  uint8_t* code = static_cast<uint8_t*>(t->m->heap->allocate(CodeCapacity));
  uintptr_t* codeMap = static_cast<uintptr_t*>
    (t->m->heap->allocate(codeMapSize(CodeCapacity)));
  memset(codeMap, 0, codeMapSize(CodeCapacity));

  object codeTable = makeCodeImage(t, &image, code, CodeCapacity);

  const unsigned HeapCapacity = 32 * 1024 * 1024;
  uintptr_t* heap = static_cast<uintptr_t*>
    (t->m->heap->allocate(HeapCapacity));
  uintptr_t* heapMap = static_cast<uintptr_t*>
    (t->m->heap->allocate(heapMapSize(HeapCapacity)));
  memset(heapMap, 0, heapMapSize(HeapCapacity));

  HeapWalker* heapWalker = makeHeapImage
    (t, &image, heap, heapMap, HeapCapacity);

  updateCodeTable(t, codeTable, code, codeMap, heapWalker->map());

  heapWalker->dispose();

  image.magic = BootImage::Magic;

  fwrite(&image, sizeof(BootImage), 1, out);

  fwrite(heapMap, pad(heapMapSize(image.heapSize)), 1, out);
  fwrite(heap, pad(image.heapSize), 1, out);

  fwrite(codeMap, pad(codeMapSize(image.codeSize)), 1, out);
  fwrite(code, pad(image.codeSize), 1, out);
}

} // namespace

int
main(int ac, const char** av)
{
  if (ac != 2) {
    fprintf(stderr, "usage: %s <classpath>\n", av[0]);
    return -1;
  }

  System* s = makeSystem(0);
  Heap* h = makeHeap(s, 128 * 1024 * 1024);
  Finder* f = makeFinder(s, av[0], 0);
  Processor* p = makeProcessor(s, h);
  Machine* m = new (h->allocate(sizeof(Machine))) Machine(s, h, f, p, 0, 0);
  Thread* t = p->makeThread(m, 0, 0);
  
  enter(t, Thread::ActiveState);
  enter(t, Thread::IdleState);

  writeBootImage(t, stdout);

  return 0;
}