/// create - create a stub if needed, otherwise return NULL
Stub* StubFactory::create(Relocation& pReloc,
uint64_t pTargetSymValue,
IRBuilder& pBuilder,
BranchIslandFactory& pBRIslandFactory)
{
// find if there is a prototype stub for the input relocation
Stub* prototype = findPrototype(pReloc,
pReloc.place(),
pTargetSymValue);
if (NULL != prototype) {
// find the island for the input relocation
BranchIsland* island = pBRIslandFactory.find(*(pReloc.targetRef().frag()));
if (NULL == island) {
island = pBRIslandFactory.produce(*(pReloc.targetRef().frag()));
}
// find if there is such a stub in the island already
assert(NULL != island);
Stub* stub = island->findStub(prototype, pReloc);
if (NULL != stub) {
// reset the branch target to the stub instead!
pReloc.setSymInfo(stub->symInfo());
}
else {
// create a stub from the prototype
stub = prototype->clone();
// build a name for stub symbol
std::string name("__");
name.append(pReloc.symInfo()->name());
name.append("_");
name.append(stub->name());
name.append("@");
name.append(island->name());
// create LDSymbol for the stub
LDSymbol* symbol =
pBuilder.AddSymbol<IRBuilder::Force, IRBuilder::Resolve>(
name,
ResolveInfo::Function,
ResolveInfo::Define,
ResolveInfo::Local,
stub->size(), // size
stub->initSymValue(), // value
FragmentRef::Create(*stub, stub->initSymValue()),
ResolveInfo::Default);
stub->setSymInfo(symbol->resolveInfo());
// add relocations of this stub (i.e., set the branch target of the stub)
for (Stub::fixup_iterator it = stub->fixup_begin(),
ie = stub->fixup_end(); it != ie; ++it) {
Relocation* reloc = Relocation::Create((*it)->type(),
*(FragmentRef::Create(*stub, (*it)->offset())),
(*it)->addend());
reloc->setSymInfo(pReloc.symInfo());
island->addRelocation(*reloc);
}
// add stub to the branch island
island->addStub(prototype, pReloc, *stub);
// reset the branch target of the input reloc to this stub instead!
pReloc.setSymInfo(stub->symInfo());
return stub;
}
}
return NULL;
}
/// create - create a stub if needed, otherwise return NULL
Stub* StubFactory::create(Relocation& pReloc,
uint64_t pTargetSymValue,
IRBuilder& pBuilder,
BranchIslandFactory& pBRIslandFactory) {
// find if there is a prototype stub for the input relocation
Stub* stub = NULL;
Stub* prototype = findPrototype(pReloc, pReloc.place(), pTargetSymValue);
if (prototype != NULL) {
const Fragment* frag = pReloc.targetRef().frag();
// find the islands for the input relocation
std::pair<BranchIsland*, BranchIsland*> islands =
pBRIslandFactory.getIslands(*frag);
if (islands.first == NULL) {
// early exit if we can not find the forward island.
return NULL;
}
// find if there is such a stub in the backward island first.
if (islands.second != NULL) {
stub = islands.second->findStub(prototype, pReloc);
}
if (stub != NULL) {
// reset the branch target to the stub instead!
pReloc.setSymInfo(stub->symInfo());
} else {
// find if there is such a stub in the forward island.
stub = islands.first->findStub(prototype, pReloc);
if (stub != NULL) {
// reset the branch target to the stub instead!
pReloc.setSymInfo(stub->symInfo());
} else {
// create a stub from the prototype
stub = prototype->clone();
// build a name for stub symbol
std::string name("__");
name.append(pReloc.symInfo()->name())
.append("_")
.append(stub->name())
.append("@")
.append(islands.first->name());
// create LDSymbol for the stub
LDSymbol* symbol =
pBuilder.AddSymbol<IRBuilder::Force, IRBuilder::Unresolve>(
name,
ResolveInfo::Function,
ResolveInfo::Define,
ResolveInfo::Local,
stub->size(), // size
stub->initSymValue(), // value
FragmentRef::Create(*stub, stub->initSymValue()),
ResolveInfo::Default);
stub->setSymInfo(symbol->resolveInfo());
// add relocations of this stub (i.e., set the branch target of the
// stub)
for (Stub::fixup_iterator it = stub->fixup_begin(),
ie = stub->fixup_end();
it != ie;
++it) {
Relocation* reloc =
Relocation::Create((*it)->type(),
*(FragmentRef::Create(*stub, (*it)->offset())),
(*it)->addend());
reloc->setSymInfo(pReloc.symInfo());
islands.first->addRelocation(*reloc);
}
// add stub to the forward branch island
islands.first->addStub(prototype, pReloc, *stub);
// reset the branch target of the input reloc to this stub instead!
pReloc.setSymInfo(stub->symInfo());
}
}
}
return stub;
}