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336afca477
Now that supportsMoveOnlyTypes is always true, these bailouts can't be reached. Delete the bailouts and the predicate.
314 lines
11 KiB
C++
314 lines
11 KiB
C++
//===--- MoveOnlyChecker.cpp ----------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2022 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "sil-move-only-checker"
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#include "swift/AST/AccessScope.h"
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#include "swift/AST/DiagnosticEngine.h"
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#include "swift/AST/DiagnosticsSIL.h"
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#include "swift/AST/SemanticAttrs.h"
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#include "swift/Basic/Debug.h"
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#include "swift/Basic/Defer.h"
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#include "swift/Basic/FrozenMultiMap.h"
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#include "swift/Basic/SmallBitVector.h"
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#include "swift/SIL/ApplySite.h"
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#include "swift/SIL/BasicBlockBits.h"
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#include "swift/SIL/BasicBlockData.h"
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#include "swift/SIL/BasicBlockDatastructures.h"
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#include "swift/SIL/BasicBlockUtils.h"
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#include "swift/SIL/Consumption.h"
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#include "swift/SIL/DebugUtils.h"
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#include "swift/SIL/FieldSensitivePrunedLiveness.h"
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#include "swift/SIL/InstructionUtils.h"
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#include "swift/SIL/MemAccessUtils.h"
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#include "swift/SIL/OSSALifetimeCompletion.h"
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#include "swift/SIL/OwnershipUtils.h"
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#include "swift/SIL/PrunedLiveness.h"
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#include "swift/SIL/SILArgument.h"
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#include "swift/SIL/SILArgumentConvention.h"
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#include "swift/SIL/SILBasicBlock.h"
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#include "swift/SIL/SILBuilder.h"
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#include "swift/SIL/SILFunction.h"
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#include "swift/SIL/SILInstruction.h"
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#include "swift/SIL/SILUndef.h"
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#include "swift/SIL/SILValue.h"
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#include "swift/SILOptimizer/Analysis/ClosureScope.h"
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#include "swift/SILOptimizer/Analysis/DeadEndBlocksAnalysis.h"
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#include "swift/SILOptimizer/Analysis/DominanceAnalysis.h"
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#include "swift/SILOptimizer/Analysis/NonLocalAccessBlockAnalysis.h"
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#include "swift/SILOptimizer/PassManager/Transforms.h"
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#include "swift/SILOptimizer/Utils/CanonicalizeOSSALifetime.h"
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#include "swift/SILOptimizer/Utils/InstructionDeleter.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/MapVector.h"
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#include "llvm/ADT/PointerIntPair.h"
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#include "llvm/ADT/PointerUnion.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/SmallBitVector.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "MoveOnlyAddressCheckerUtils.h"
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#include "MoveOnlyDiagnostics.h"
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#include "MoveOnlyObjectCheckerUtils.h"
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#include "MoveOnlyUtils.h"
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using namespace swift;
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using namespace swift::siloptimizer;
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//===----------------------------------------------------------------------===//
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// MARK: Top Level Object Entrypoint
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//===----------------------------------------------------------------------===//
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namespace {
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struct MoveOnlyChecker {
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DiagnosticEmitter diagnosticEmitter;
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SILFunction *fn;
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DominanceInfo *domTree;
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PostOrderAnalysis *poa;
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bool madeChange = false;
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borrowtodestructure::IntervalMapAllocator allocator;
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MoveOnlyChecker(SILFunction *fn, DominanceInfo *domTree,
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PostOrderAnalysis *poa)
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: diagnosticEmitter(fn), fn(fn), domTree(domTree), poa(poa) {
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}
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void checkObjects();
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void completeObjectLifetimes(ArrayRef<MarkUnresolvedNonCopyableValueInst *>);
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void checkAddresses();
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};
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} // namespace
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void MoveOnlyChecker::checkObjects() {
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llvm::SmallSetVector<MarkUnresolvedNonCopyableValueInst *, 32>
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moveIntroducersToProcess;
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unsigned diagCount = diagnosticEmitter.getDiagnosticCount();
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madeChange |= searchForCandidateObjectMarkUnresolvedNonCopyableValueInsts(
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fn, moveIntroducersToProcess, diagnosticEmitter);
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LLVM_DEBUG(
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llvm::dbgs()
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<< "Emitting diagnostic when checking for mark must check inst: "
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<< (diagCount != diagnosticEmitter.getDiagnosticCount() ? "yes" : "no")
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<< '\n');
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if (moveIntroducersToProcess.empty()) {
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LLVM_DEBUG(llvm::dbgs()
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<< "No move introducers found?! Returning early?!\n");
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return;
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}
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completeObjectLifetimes(moveIntroducersToProcess.getArrayRef());
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MoveOnlyObjectChecker checker{diagnosticEmitter, domTree, poa, allocator};
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madeChange |= checker.check(moveIntroducersToProcess);
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}
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void MoveOnlyChecker::completeObjectLifetimes(
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ArrayRef<MarkUnresolvedNonCopyableValueInst *> insts) {
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// TODO: Delete once OSSALifetimeCompletion is run as part of SILGenCleanup.
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OSSALifetimeCompletion completion(fn, domTree);
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// Collect all values derived from each mark_unresolved_non_copyable_value
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// instruction via ownership instructions and phis.
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ValueWorklist transitiveValues(fn);
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for (auto *inst : insts) {
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transitiveValues.push(inst);
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}
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while (auto value = transitiveValues.pop()) {
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for (auto *use : value->getUses()) {
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auto *user = use->getUser();
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switch (user->getKind()) {
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case SILInstructionKind::BeginBorrowInst:
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case SILInstructionKind::CopyValueInst:
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case SILInstructionKind::MoveValueInst:
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transitiveValues.pushIfNotVisited(cast<SingleValueInstruction>(user));
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break;
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case SILInstructionKind::BranchInst: {
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PhiOperand po(use);
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transitiveValues.pushIfNotVisited(po.getValue());
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break;
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}
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default: {
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auto forward = ForwardingOperation(user);
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if (!forward)
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continue;
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forward.visitForwardedValues([&transitiveValues](auto forwarded) {
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transitiveValues.pushIfNotVisited(forwarded);
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return true;
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});
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break;
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}
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}
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}
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}
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// Complete the lifetime of each collected value. This is a subset of the
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// work that SILGenCleanup will do.
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for (auto *block : poa->get(fn)->getPostOrder()) {
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for (SILInstruction &inst : reverse(*block)) {
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for (auto result : inst.getResults()) {
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if (!transitiveValues.isVisited(result))
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continue;
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if (completion.completeOSSALifetime(result) ==
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LifetimeCompletion::WasCompleted) {
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madeChange = true;
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}
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}
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}
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for (SILArgument *arg : block->getArguments()) {
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assert(!arg->isReborrow() && "reborrows not legal at this SIL stage");
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if (!transitiveValues.isVisited(arg))
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continue;
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if (completion.completeOSSALifetime(arg) ==
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LifetimeCompletion::WasCompleted) {
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madeChange = true;
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}
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}
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}
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}
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void MoveOnlyChecker::checkAddresses() {
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unsigned diagCount = diagnosticEmitter.getDiagnosticCount();
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llvm::SmallSetVector<MarkUnresolvedNonCopyableValueInst *, 32>
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moveIntroducersToProcess;
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searchForCandidateAddressMarkUnresolvedNonCopyableValueInsts(
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fn, moveIntroducersToProcess, diagnosticEmitter);
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LLVM_DEBUG(
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llvm::dbgs()
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<< "Emitting diagnostic when checking for mark must check inst: "
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<< (diagCount != diagnosticEmitter.getDiagnosticCount() ? "yes" : "no")
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<< '\n');
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if (moveIntroducersToProcess.empty()) {
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LLVM_DEBUG(llvm::dbgs()
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<< "No move introducers found?! Returning early?!\n");
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return;
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}
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MoveOnlyAddressChecker checker{fn, diagnosticEmitter, allocator, domTree,
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poa};
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madeChange |= checker.check(moveIntroducersToProcess);
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}
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//===----------------------------------------------------------------------===//
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// MARK: Top Level Entrypoint
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//===----------------------------------------------------------------------===//
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namespace {
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class MoveOnlyCheckerPass : public SILFunctionTransform {
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void run() override {
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auto *fn = getFunction();
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// Don't rerun diagnostics on deserialized functions.
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if (getFunction()->wasDeserializedCanonical())
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return;
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assert(fn->getModule().getStage() == SILStage::Raw &&
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"Should only run on Raw SIL");
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// If an earlier pass asked us to eliminate the function body if it's
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// unused, and the function is in fact unused, do that now.
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if (fn->hasSemanticsAttr(semantics::MOVEONLY_DELETE_IF_UNUSED)) {
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if (fn->getRefCount() == 0
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&& !isPossiblyUsedExternally(fn->getLinkage(),
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fn->getModule().isWholeModule())) {
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LLVM_DEBUG(llvm::dbgs() << "===> Deleting unused function " << fn->getName() << "'s body that was marked for deletion\n");
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// Remove all non-entry blocks.
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auto entryBB = fn->begin();
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auto nextBB = std::next(entryBB);
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while (nextBB != fn->end()) {
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auto thisBB = nextBB;
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++nextBB;
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thisBB->eraseFromParent();
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}
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// Rewrite the entry block to only contain an unreachable.
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auto loc = entryBB->begin()->getLoc();
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entryBB->eraseAllInstructions(fn->getModule());
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{
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SILBuilder b(&*entryBB);
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b.createUnreachable(loc);
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}
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// If the function has shared linkage, reduce this version to private
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// linkage, because we don't want the deleted-body form to win in any
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// ODR shootouts.
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if (fn->getLinkage() == SILLinkage::Shared) {
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fn->setLinkage(SILLinkage::Private);
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}
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invalidateAnalysis(SILAnalysis::InvalidationKind::FunctionBody);
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return;
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}
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// If the function wasn't unused, let it continue into diagnostics.
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// This would come up if a closure function somehow was used in different
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// functions with different escape analysis results. This shouldn't really
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// be possible, and we should try harder to make it impossible, but if
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// it does happen now, the least bad thing to do is to proceed with
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// move checking. This will either succeed and make sure the original
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// function contains valid SIL, or raise errors relating to the use
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// of the captures in an escaping way, which is the right thing to do
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// if they are in fact escapable.
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LLVM_DEBUG(llvm::dbgs() << "===> Function " << fn->getName()
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<< " was marked to be deleted, but has uses. Continuing with move checking\n");
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}
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// If an earlier pass told use to not emit diagnostics for this function,
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// clean up any copies, invalidate the analysis, and return early.
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if (fn->hasSemanticsAttr(semantics::NO_MOVEONLY_DIAGNOSTICS)) {
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if (cleanupNonCopyableCopiesAfterEmittingDiagnostic(getFunction()))
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invalidateAnalysis(SILAnalysis::InvalidationKind::Instructions);
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return;
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}
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LLVM_DEBUG(llvm::dbgs()
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<< "===> MoveOnly Checker. Visiting: " << fn->getName() << '\n');
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MoveOnlyChecker checker(
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fn, getAnalysis<DominanceAnalysis>()->get(fn),
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getAnalysis<PostOrderAnalysis>());
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checker.checkObjects();
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checker.checkAddresses();
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// If we did not emit any diagnostics, emit an error on any copies that
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// remain. If we emitted a diagnostic, we just want to rewrite all of the
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// non-copyable copies into explicit variants below and let the user
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// recompile.
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if (!checker.diagnosticEmitter.emittedDiagnostic()) {
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emitCheckerMissedCopyOfNonCopyableTypeErrors(fn,
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checker.diagnosticEmitter);
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}
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checker.madeChange |=
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cleanupNonCopyableCopiesAfterEmittingDiagnostic(fn);
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if (checker.madeChange)
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invalidateAnalysis(SILAnalysis::InvalidationKind::Instructions);
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}
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};
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} // namespace
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SILTransform *swift::createMoveOnlyChecker() {
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return new MoveOnlyCheckerPass();
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}
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