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Check for lower slice bound when bounds checking is enabled

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This commit is contained in:
Alexey Prokhin 2011-01-03 16:50:08 +03:00
parent fd52810f1a
commit 1c59eed83a
3 changed files with 38 additions and 9 deletions
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35
gen/arrays.cpp
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@ -1274,7 +1274,7 @@ DValue* DtoCastArray(Loc& loc, DValue* u, Type* to)
else {
size_t i = (tosize * totype->nextOf()->size() - 1) / fromtype->nextOf()->size();
DConstValue index(Type::tsize_t, DtoConstSize_t(i));
DtoArrayBoundsCheck(loc, u, &index, false);
DtoArrayBoundsCheck(loc, u, &index);
rval = DtoArrayPtr(u);
rval = DtoBitCast(rval, getPtrToType(tolltype));
@ -1302,24 +1302,49 @@ DValue* DtoCastArray(Loc& loc, DValue* u, Type* to)
}
//////////////////////////////////////////////////////////////////////////////////////////
void DtoArrayBoundsCheck(Loc& loc, DValue* arr, DValue* index, bool isslice)
void DtoArrayBoundsCheck(Loc& loc, DValue* arr, DValue* index, DValue* lowerBound)
{
Type* arrty = arr->getType()->toBasetype();
#if DMDV2
assert((arrty->ty == Tsarray || arrty->ty == Tarray || arrty->ty == Tpointer) &&
"Can only array bounds check for static or dynamic arrays");
#else
assert((arrty->ty == Tsarray || arrty->ty == Tarray) &&
"Can only array bounds check for static or dynamic arrays");
#endif
// static arrays could get static checks for static indices
// but shouldn't since it might be generic code that's never executed
// runtime check
bool lengthUnknown = arrty->ty == Tpointer;
llvm::BasicBlock* oldend = gIR->scopeend();
llvm::BasicBlock* failbb = llvm::BasicBlock::Create(gIR->context(), "arrayboundscheckfail", gIR->topfunc(), oldend);
llvm::BasicBlock* okbb = llvm::BasicBlock::Create(gIR->context(), "arrayboundsok", gIR->topfunc(), oldend);
LLValue* cond = 0;
llvm::ICmpInst::Predicate cmpop = isslice ? llvm::ICmpInst::ICMP_ULE : llvm::ICmpInst::ICMP_ULT;
LLValue* cond = gIR->ir->CreateICmp(cmpop, index->getRVal(), DtoArrayLen(arr), "boundscheck");
gIR->ir->CreateCondBr(cond, okbb, failbb);
if (!lengthUnknown) {
// if lowerBound is not NULL, we're checking slice
llvm::ICmpInst::Predicate cmpop = lowerBound ? llvm::ICmpInst::ICMP_ULE : llvm::ICmpInst::ICMP_ULT;
// check for upper bound
cond = gIR->ir->CreateICmp(cmpop, index->getRVal(), DtoArrayLen(arr), "boundscheck");
}
if (!lowerBound) {
assert(cond);
gIR->ir->CreateCondBr(cond, okbb, failbb);
} else {
if (!lengthUnknown) {
llvm::BasicBlock* locheckbb = llvm::BasicBlock::Create(gIR->context(), "arrayboundschecklowerbound", gIR->topfunc(), oldend);
gIR->ir->CreateCondBr(cond, locheckbb, failbb);
gIR->scope() = IRScope(locheckbb, failbb);
}
// check for lower bound
cond = gIR->ir->CreateICmp(llvm::ICmpInst::ICMP_ULE, lowerBound->getRVal(), index->getRVal(), "boundscheck");
gIR->ir->CreateCondBr(cond, okbb, failbb);
}
// set up failbb to call the array bounds error runtime function