/// Returns true when the apply calls the Standard Library swap().
/// Used for fix-its to suggest replacing with Collection.swapAt()
/// on exclusivity violations.
static bool isCallToStandardLibrarySwap(ApplyInst *AI, ASTContext &Ctx) {
SILFunction *SF = AI->getReferencedFunction();
if (!SF)
return false;
if (!SF->hasLocation())
return false;
auto *FD = SF->getLocation().getAsASTNode<FuncDecl>();
if (!FD)
return false;
return FD == Ctx.getSwap();
}
void StackPromoter::tryPromoteAlloc(SILInstruction *I) {
SILInstruction *AllocInsertionPoint = nullptr;
SILInstruction *DeallocInsertionPoint = nullptr;
if (!canPromoteAlloc(I, AllocInsertionPoint, DeallocInsertionPoint))
return;
DEBUG(llvm::dbgs() << "Promoted " << *I);
DEBUG(llvm::dbgs() << " in " << I->getFunction()->getName() << '\n');
NumStackPromoted++;
SILBuilder B(DeallocInsertionPoint);
if (auto *ARI = dyn_cast<AllocRefInst>(I)) {
// It's an object allocation. We set the [stack] attribute in the alloc_ref.
ARI->setStackAllocatable();
if (AllocInsertionPoint)
ARI->moveBefore(AllocInsertionPoint);
/// And create a dealloc_ref [stack] at the end of the object's lifetime.
B.createDeallocRef(I->getLoc(), I, true);
ChangedInsts = true;
return;
}
if (auto *AI = dyn_cast<ApplyInst>(I)) {
assert(!AllocInsertionPoint && "can't move call to swift_bufferAlloc");
// It's an array buffer allocation.
auto *OldFRI = cast<FunctionRefInst>(AI->getCallee());
SILFunction *OldF = OldFRI->getReferencedFunction();
SILLocation loc = (OldF->hasLocation() ? OldF->getLocation() : AI->getLoc());
SILFunction *DeallocFun = getBufferDeallocFunc(OldF, loc);
// We insert a swift_bufferDeallocateFromStack at the end of the buffer's
// lifetime.
auto *DeallocFRI = B.createFunctionRef(OldFRI->getLoc(), DeallocFun);
B.createApply(loc, DeallocFRI, { AI }, false);
// And replace the call to swift_bufferAllocate with a call to
// swift_bufferAllocateOnStack.
B.setInsertionPoint(AI);
auto *AllocFRI = B.createFunctionRef(OldFRI->getLoc(),
getBufferAllocFunc(OldF, loc));
AI->setOperand(0, AllocFRI);
ChangedCalls = true;
return;
}
llvm_unreachable("unhandled allocation instruction");
}