/// Generate a new apply of a function_ref to replace an apply of a
/// witness_method when we've determined the actual function we'll end
/// up calling.
static ApplySite
devirtualizeWitnessMethod(ApplySite AI, SILFunction *F,
ProtocolConformanceRef C, OptRemark::Emitter *ORE) {
// We know the witness thunk and the corresponding set of substitutions
// required to invoke the protocol method at this point.
auto &Module = AI.getModule();
// Collect all the required substitutions.
//
// The complete set of substitutions may be different, e.g. because the found
// witness thunk F may have been created by a specialization pass and have
// additional generic parameters.
auto SubMap = getWitnessMethodSubstitutions(Module, AI, F, C);
// Figure out the exact bound type of the function to be called by
// applying all substitutions.
auto CalleeCanType = F->getLoweredFunctionType();
auto SubstCalleeCanType = CalleeCanType->substGenericArgs(Module, SubMap);
// Collect arguments from the apply instruction.
auto Arguments = SmallVector<SILValue, 4>();
// Iterate over the non self arguments and add them to the
// new argument list, upcasting when required.
SILBuilderWithScope B(AI.getInstruction());
SILFunctionConventions substConv(SubstCalleeCanType, Module);
unsigned substArgIdx = AI.getCalleeArgIndexOfFirstAppliedArg();
for (auto arg : AI.getArguments()) {
auto paramType = substConv.getSILArgumentType(substArgIdx++);
if (arg->getType() != paramType)
arg = castValueToABICompatibleType(&B, AI.getLoc(), arg,
arg->getType(), paramType);
Arguments.push_back(arg);
}
assert(substArgIdx == substConv.getNumSILArguments());
// Replace old apply instruction by a new apply instruction that invokes
// the witness thunk.
SILBuilderWithScope Builder(AI.getInstruction());
SILLocation Loc = AI.getLoc();
FunctionRefInst *FRI = Builder.createFunctionRef(Loc, F);
ApplySite SAI = replaceApplySite(Builder, Loc, AI, FRI, SubMap, Arguments,
substConv);
if (ORE)
ORE->emit([&]() {
using namespace OptRemark;
return RemarkPassed("WitnessMethodDevirtualized", *AI.getInstruction())
<< "Devirtualized call to " << NV("Method", F);
});
NumWitnessDevirt++;
return SAI;
}
/// For each argument in the range of the callee arguments being applied at the
/// given apply site, use the summary analysis to determine whether the
/// arguments will be accessed in a way that conflicts with any currently in
/// progress accesses. If so, diagnose.
static void checkCaptureAccess(ApplySite Apply, AccessState &State) {
SILFunction *Callee = Apply.getCalleeFunction();
if (!Callee || Callee->empty())
return;
const AccessSummaryAnalysis::FunctionSummary &FS =
State.ASA->getOrCreateSummary(Callee);
for (unsigned ArgumentIndex : range(Apply.getNumArguments())) {
unsigned CalleeIndex =
Apply.getCalleeArgIndexOfFirstAppliedArg() + ArgumentIndex;
const AccessSummaryAnalysis::ArgumentSummary &AS =
FS.getAccessForArgument(CalleeIndex);
const auto &SubAccesses = AS.getSubAccesses();
// Is the capture accessed in the callee?
if (SubAccesses.empty())
continue;
SILValue Argument = Apply.getArgument(ArgumentIndex);
assert(Argument->getType().isAddress());
// A valid AccessedStorage should alway sbe found because Unsafe accesses
// are not tracked by AccessSummaryAnalysis.
const AccessedStorage &Storage = findValidAccessedStorage(Argument);
auto AccessIt = State.Accesses->find(Storage);
// Are there any accesses in progress at the time of the call?
if (AccessIt == State.Accesses->end())
continue;
const AccessInfo &Info = AccessIt->getSecond();
if (auto Conflict = findConflictingArgumentAccess(AS, Storage, Info))
State.ConflictingAccesses.push_back(*Conflict);
}
}
/// Generate a new apply of a function_ref to replace an apply of a
/// witness_method when we've determined the actual function we'll end
/// up calling.
static ApplySite devirtualizeWitnessMethod(ApplySite AI, SILFunction *F,
ProtocolConformanceRef C) {
// We know the witness thunk and the corresponding set of substitutions
// required to invoke the protocol method at this point.
auto &Module = AI.getModule();
// Collect all the required substitutions.
//
// The complete set of substitutions may be different, e.g. because the found
// witness thunk F may have been created by a specialization pass and have
// additional generic parameters.
SmallVector<Substitution, 4> NewSubs;
getWitnessMethodSubstitutions(AI, F, C, NewSubs);
// Figure out the exact bound type of the function to be called by
// applying all substitutions.
auto CalleeCanType = F->getLoweredFunctionType();
auto SubstCalleeCanType = CalleeCanType->substGenericArgs(Module, NewSubs);
// Collect arguments from the apply instruction.
auto Arguments = SmallVector<SILValue, 4>();
// Iterate over the non self arguments and add them to the
// new argument list, upcasting when required.
SILBuilderWithScope B(AI.getInstruction());
SILFunctionConventions substConv(SubstCalleeCanType, Module);
unsigned substArgIdx = AI.getCalleeArgIndexOfFirstAppliedArg();
for (auto arg : AI.getArguments()) {
auto paramType = substConv.getSILArgumentType(substArgIdx++);
if (arg->getType() != paramType)
arg = castValueToABICompatibleType(&B, AI.getLoc(), arg,
arg->getType(), paramType);
Arguments.push_back(arg);
}
assert(substArgIdx == substConv.getNumSILArguments());
// Replace old apply instruction by a new apply instruction that invokes
// the witness thunk.
SILBuilderWithScope Builder(AI.getInstruction());
SILLocation Loc = AI.getLoc();
FunctionRefInst *FRI = Builder.createFunctionRef(Loc, F);
auto SubstCalleeSILType = SILType::getPrimitiveObjectType(SubstCalleeCanType);
auto ResultSILType = substConv.getSILResultType();
ApplySite SAI;
if (auto *A = dyn_cast<ApplyInst>(AI))
SAI = Builder.createApply(Loc, FRI, SubstCalleeSILType,
ResultSILType, NewSubs, Arguments,
A->isNonThrowing());
if (auto *TAI = dyn_cast<TryApplyInst>(AI))
SAI = Builder.createTryApply(Loc, FRI, SubstCalleeSILType,
NewSubs, Arguments,
TAI->getNormalBB(), TAI->getErrorBB());
if (auto *PAI = dyn_cast<PartialApplyInst>(AI))
SAI = Builder.createPartialApply(Loc, FRI, SubstCalleeSILType,
NewSubs, Arguments, PAI->getType());
NumWitnessDevirt++;
return SAI;
}
