Files
swift-mirror/lib/SILOptimizer/Mandatory/MoveOnlyChecker.cpp
2025-08-18 09:45:21 -07:00

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10 KiB
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//===--- MoveOnlyChecker.cpp ----------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2022 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "sil-move-only-checker"
#include "swift/AST/AccessScope.h"
#include "swift/AST/DiagnosticEngine.h"
#include "swift/AST/DiagnosticsSIL.h"
#include "swift/AST/SemanticAttrs.h"
#include "swift/Basic/Assertions.h"
#include "swift/Basic/Debug.h"
#include "swift/Basic/Defer.h"
#include "swift/Basic/FrozenMultiMap.h"
#include "swift/Basic/SmallBitVector.h"
#include "swift/SIL/ApplySite.h"
#include "swift/SIL/BasicBlockBits.h"
#include "swift/SIL/BasicBlockData.h"
#include "swift/SIL/BasicBlockDatastructures.h"
#include "swift/SIL/BasicBlockUtils.h"
#include "swift/SIL/Consumption.h"
#include "swift/SIL/DebugUtils.h"
#include "swift/SIL/FieldSensitivePrunedLiveness.h"
#include "swift/SIL/InstructionUtils.h"
#include "swift/SIL/MemAccessUtils.h"
#include "swift/SIL/OSSACompleteLifetime.h"
#include "swift/SIL/OwnershipUtils.h"
#include "swift/SIL/PrunedLiveness.h"
#include "swift/SIL/SILArgument.h"
#include "swift/SIL/SILArgumentConvention.h"
#include "swift/SIL/SILBasicBlock.h"
#include "swift/SIL/SILBuilder.h"
#include "swift/SIL/SILFunction.h"
#include "swift/SIL/SILInstruction.h"
#include "swift/SIL/SILUndef.h"
#include "swift/SIL/SILValue.h"
#include "swift/SILOptimizer/Analysis/ClosureScope.h"
#include "swift/SILOptimizer/Analysis/DeadEndBlocksAnalysis.h"
#include "swift/SILOptimizer/Analysis/DominanceAnalysis.h"
#include "swift/SILOptimizer/Analysis/NonLocalAccessBlockAnalysis.h"
#include "swift/SILOptimizer/PassManager/Transforms.h"
#include "swift/SILOptimizer/Utils/InstructionDeleter.h"
#include "swift/SILOptimizer/Utils/OSSACanonicalizeOwned.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "MoveOnlyAddressCheckerUtils.h"
#include "MoveOnlyDiagnostics.h"
#include "MoveOnlyObjectCheckerUtils.h"
#include "MoveOnlyUtils.h"
using namespace swift;
using namespace swift::siloptimizer;
//===----------------------------------------------------------------------===//
// MARK: Top Level Object Entrypoint
//===----------------------------------------------------------------------===//
namespace {
struct MoveOnlyChecker {
DiagnosticEmitter diagnosticEmitter;
SILFunction *fn;
DominanceInfo *domTree;
PostOrderAnalysis *poa;
DeadEndBlocksAnalysis *deba;
bool madeChange = false;
borrowtodestructure::IntervalMapAllocator allocator;
MoveOnlyChecker(SILFunction *fn, DominanceInfo *domTree,
PostOrderAnalysis *poa, DeadEndBlocksAnalysis *deba)
: diagnosticEmitter(fn), fn(fn), domTree(domTree), poa(poa), deba(deba) {}
void checkObjects();
void completeObjectLifetimes(ArrayRef<MarkUnresolvedNonCopyableValueInst *>);
void checkAddresses();
};
} // namespace
void MoveOnlyChecker::checkObjects() {
llvm::SmallSetVector<MarkUnresolvedNonCopyableValueInst *, 32>
moveIntroducersToProcess;
unsigned diagCount = diagnosticEmitter.getDiagnosticCount();
madeChange |= searchForCandidateObjectMarkUnresolvedNonCopyableValueInsts(
fn, moveIntroducersToProcess, diagnosticEmitter);
LLVM_DEBUG(
llvm::dbgs()
<< "Emitting diagnostic when checking for mark must check inst: "
<< (diagCount != diagnosticEmitter.getDiagnosticCount() ? "yes" : "no")
<< '\n');
if (moveIntroducersToProcess.empty()) {
LLVM_DEBUG(llvm::dbgs()
<< "No move introducers found?! Returning early?!\n");
return;
}
completeObjectLifetimes(moveIntroducersToProcess.getArrayRef());
MoveOnlyObjectChecker checker{diagnosticEmitter, domTree, deba, poa,
allocator};
madeChange |= checker.check(moveIntroducersToProcess);
}
void MoveOnlyChecker::completeObjectLifetimes(
ArrayRef<MarkUnresolvedNonCopyableValueInst *> insts) {
// TODO: Delete once OSSACompleteLifetime is run as part of SILGenCleanup.
OSSACompleteLifetime completion(fn, domTree, *deba->get(fn));
// Collect all values derived from each mark_unresolved_non_copyable_value
// instruction via ownership instructions and phis.
ValueWorklist transitiveValues(fn);
for (auto *inst : insts) {
transitiveValues.push(inst);
}
while (auto value = transitiveValues.pop()) {
for (auto *use : value->getUses()) {
auto *user = use->getUser();
switch (user->getKind()) {
case SILInstructionKind::BeginBorrowInst:
case SILInstructionKind::CopyValueInst:
case SILInstructionKind::MoveValueInst:
transitiveValues.pushIfNotVisited(cast<SingleValueInstruction>(user));
break;
case SILInstructionKind::BranchInst: {
PhiOperand po(use);
transitiveValues.pushIfNotVisited(po.getValue());
break;
}
default: {
auto forward = ForwardingOperation(user);
if (!forward)
continue;
forward.visitForwardedValues([&transitiveValues](auto forwarded) {
transitiveValues.pushIfNotVisited(forwarded);
return true;
});
break;
}
}
}
}
// Complete the lifetime of each collected value. This is a subset of the
// work that SILGenCleanup will do.
for (auto *block : poa->get(fn)->getPostOrder()) {
for (SILInstruction &inst : reverse(*block)) {
for (auto result : inst.getResults()) {
if (llvm::any_of(result->getUsers(),
[](auto *user) { return isa<BranchInst>(user); })) {
continue;
}
if (!transitiveValues.isVisited(result))
continue;
if (completion.completeOSSALifetime(
result, OSSACompleteLifetime::Boundary::Availability) ==
LifetimeCompletion::WasCompleted) {
madeChange = true;
}
}
}
for (SILArgument *arg : block->getArguments()) {
if (arg->isReborrow()) {
continue;
}
if (!transitiveValues.isVisited(arg))
continue;
if (completion.completeOSSALifetime(
arg, OSSACompleteLifetime::Boundary::Availability) ==
LifetimeCompletion::WasCompleted) {
madeChange = true;
}
}
}
}
void MoveOnlyChecker::checkAddresses() {
unsigned diagCount = diagnosticEmitter.getDiagnosticCount();
llvm::SmallSetVector<MarkUnresolvedNonCopyableValueInst *, 32>
moveIntroducersToProcess;
searchForCandidateAddressMarkUnresolvedNonCopyableValueInsts(
fn, poa, moveIntroducersToProcess, diagnosticEmitter);
LLVM_DEBUG(
llvm::dbgs()
<< "Emitting diagnostic when checking for mark must check inst: "
<< (diagCount != diagnosticEmitter.getDiagnosticCount() ? "yes" : "no")
<< '\n');
if (moveIntroducersToProcess.empty()) {
LLVM_DEBUG(llvm::dbgs()
<< "No move introducers found?! Returning early?!\n");
return;
}
MoveOnlyAddressChecker checker{
fn, diagnosticEmitter, allocator, domTree, poa, deba};
madeChange |= checker.completeLifetimes();
madeChange |= checker.check(moveIntroducersToProcess);
}
//===----------------------------------------------------------------------===//
// MARK: Top Level Entrypoint
//===----------------------------------------------------------------------===//
namespace {
static bool canonicalizeLoadBorrows(SILFunction *F) {
bool changed = false;
for (auto &block : *F) {
for (auto &inst : block) {
if (auto *lbi = dyn_cast<LoadBorrowInst>(&inst)) {
if (lbi->isUnchecked()) {
changed = true;
lbi->setUnchecked(false);
}
}
}
}
return changed;
}
class MoveOnlyCheckerPass : public SILFunctionTransform {
void run() override {
auto *fn = getFunction();
// Don't rerun diagnostics on deserialized functions.
if (getFunction()->wasDeserializedCanonical())
return;
assert(fn->getModule().getStage() == SILStage::Raw &&
"Should only run on Raw SIL");
// If an earlier pass told use to not emit diagnostics for this function,
// clean up any copies, invalidate the analysis, and return early.
if (fn->hasSemanticsAttr(semantics::NO_MOVEONLY_DIAGNOSTICS)) {
bool didChange = canonicalizeLoadBorrows(fn);
didChange |= cleanupNonCopyableCopiesAfterEmittingDiagnostic(getFunction());
if (didChange) {
invalidateAnalysis(SILAnalysis::InvalidationKind::Instructions);
}
return;
}
LLVM_DEBUG(llvm::dbgs()
<< "===> MoveOnly Checker. Visiting: " << fn->getName() << '\n');
MoveOnlyChecker checker(fn, getAnalysis<DominanceAnalysis>()->get(fn),
getAnalysis<PostOrderAnalysis>(),
getAnalysis<DeadEndBlocksAnalysis>());
checker.checkObjects();
checker.checkAddresses();
// If we did not emit any diagnostics, emit an error on any copies that
// remain. If we emitted a diagnostic, we just want to rewrite all of the
// non-copyable copies into explicit variants below and let the user
// recompile.
if (!checker.diagnosticEmitter.emittedDiagnostic()) {
emitCheckerMissedCopyOfNonCopyableTypeErrors(fn,
checker.diagnosticEmitter);
}
// Remaining borrows
// should be correctly immutable. We can canonicalize any remaining
// `load_borrow [unchecked]` instructions.
checker.madeChange |= canonicalizeLoadBorrows(fn);
checker.madeChange |=
cleanupNonCopyableCopiesAfterEmittingDiagnostic(fn);
if (checker.madeChange)
invalidateAnalysis(SILAnalysis::InvalidationKind::Instructions);
}
};
} // namespace
SILTransform *swift::createMoveOnlyChecker() {
return new MoveOnlyCheckerPass();
}