// // Copyright (c) rev.ng Srls. See LICENSE.md for details. // #include #include #include "llvm/ADT/SCCIterator.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/SmallString.h" #include "llvm/Support/FormattedStream.h" #include "llvm/Support/raw_ostream.h" #include "revng/ADT/FilteredGraphTraits.h" #include "revng/Support/Assert.h" #include "revng/Support/Debug.h" #include "revng/Support/DebugHelper.h" #include "revng-c/DataLayoutAnalysis/DLATypeSystem.h" #include "DLAHelpers.h" using namespace llvm; using NodeAllocatorT = SpecificBumpPtrAllocator; void *operator new(size_t, NodeAllocatorT &NodeAllocator) { return NodeAllocator.Allocate(); } namespace dla { void OffsetExpression::print(llvm::raw_ostream &OS) const { OS << "Off: " << Offset; auto NStrides = Strides.size(); revng_assert(NStrides == TripCounts.size()); if (not Strides.empty()) { for (decltype(NStrides) N = 0; N < NStrides; ++N) { OS << ", {" << Strides[N] << ','; if (TripCounts[N].has_value()) OS << TripCounts[N].value(); else OS << "none"; OS << '}'; } } } void LayoutTypePtr::print(raw_ostream &Out) const { Out << '{'; Out << "0x"; Out.write_hex(reinterpret_cast(V)); Out << " ["; if (isa(V)) { Out << "fname: " << V->getName(); } else { if (auto *I = dyn_cast(V)) Out << "In Func: " << I->getFunction()->getName() << " Instr: "; else if (auto *A = dyn_cast(V)) Out << "In Func: " << A->getParent()->getName() << " Arg: "; Out.write_escaped(getName(V)); } Out << "], 0x"; Out.write_hex(FieldIdx); Out << '}'; } void LayoutTypeSystemNode::print(llvm::raw_ostream &OS) const { OS << "LTSN ID: " << ID; } namespace { static constexpr size_t str_len(const char *S) { return S ? (*S ? (1 + str_len(S + 1)) : 0UL) : 0UL; } // We use \l here instead of \n, because graphviz has this sick way of saying // that the text in the node labels should be left-justified static constexpr const char DoRet[] = "\\l"; static constexpr const char NoRet[] = ""; static_assert(sizeof(DoRet) == (str_len(DoRet) + 1)); static_assert(sizeof(NoRet) == (str_len(NoRet) + 1)); static constexpr const char Equal[] = "Equal"; static constexpr const char Inherits[] = "Inherits from"; static constexpr const char Instance[] = "Has Instance of: "; static constexpr const char Unexpected[] = "Unexpected!"; static_assert(sizeof(Equal) == (str_len(Equal) + 1)); static_assert(sizeof(Inherits) == (str_len(Inherits) + 1)); static_assert(sizeof(Instance) == (str_len(Instance) + 1)); static_assert(sizeof(Unexpected) == (str_len(Unexpected) + 1)); } // end unnamed namespace void LayoutTypeSystem::dumpDotOnFile(const char *FName) const { std::error_code EC; raw_fd_ostream DotFile(FName, EC); revng_check(not EC, "Could not open file for printing LayoutTypeSystem dot"); DotFile << "digraph LayoutTypeSystem {\n"; DotFile << " // List of nodes\n"; for (const LayoutTypeSystemNode *L : getLayoutsRange()) { DotFile << " node_" << L->ID << " [shape=rect,label=\"NODE ID: " << L->ID << " Size: " << L->Size << " InterferingChild: "; llvm::SmallVector PtrUses; switch (L->InterferingInfo) { case Unknown: DotFile << 'U'; break; case AllChildrenAreInterfering: DotFile << 'A'; break; case AllChildrenAreNonInterfering: DotFile << 'N'; break; default: revng_unreachable(); } DebugPrinter->printNodeContent(*this, L, DotFile); DotFile << "\"];\n"; } DotFile << " // List of edges\n"; for (LayoutTypeSystemNode *L : getLayoutsRange()) { uint64_t SrcNodeId = L->ID; for (const auto &PredP : L->Predecessors) { const TypeLinkTag *PredTag = PredP.second; const auto SameLink = [&](auto &OtherPair) { return SrcNodeId == OtherPair.first->ID and PredTag == OtherPair.second; }; revng_assert(std::any_of(PredP.first->Successors.begin(), PredP.first->Successors.end(), SameLink)); } std::string Extra; for (const auto &SuccP : L->Successors) { const TypeLinkTag *EdgeTag = SuccP.second; const auto SameLink = [&](auto &OtherPair) { return SrcNodeId == OtherPair.first->ID and EdgeTag == OtherPair.second; }; revng_assert(std::any_of(SuccP.first->Predecessors.begin(), SuccP.first->Predecessors.end(), SameLink)); const auto *TgtNode = SuccP.first; const char *EdgeLabel = nullptr; size_t LabelSize = 0; Extra.clear(); switch (EdgeTag->getKind()) { case TypeLinkTag::LK_Equality: { EdgeLabel = Equal; LabelSize = sizeof(Equal) - 1; } break; case TypeLinkTag::LK_Instance: { EdgeLabel = Instance; LabelSize = sizeof(Instance) - 1; Extra = dumpToString(EdgeTag->getOffsetExpr()); } break; case TypeLinkTag::LK_Inheritance: { EdgeLabel = Inherits; LabelSize = sizeof(Inherits) - 1; } break; default: { EdgeLabel = Unexpected; LabelSize = sizeof(Unexpected) - 1; } break; } DotFile << " node_" << SrcNodeId << " -> node_" << TgtNode->ID << " [label=\"" << StringRef(EdgeLabel, LabelSize) << Extra << "\"];\n"; } } DotFile << "}\n"; } LayoutTypeSystemNode *LayoutTypeSystem::createArtificialLayoutType() { using LTSN = LayoutTypeSystemNode; LTSN *New = new (NodeAllocator) LayoutTypeSystemNode(NID); revng_assert(New); ++NID; EqClasses.growBy1(); bool Success = Layouts.insert(New).second; revng_assert(Success); return New; } static void fixPredSucc(LayoutTypeSystemNode *From, LayoutTypeSystemNode *Into) { // Helper lambdas const auto IsFrom = [From](const LayoutTypeSystemNode::Link &L) { return L.first == From; }; const auto IsInto = [Into](const LayoutTypeSystemNode::Link &L) { return L.first == Into; }; // All the predecessors of all the successors of From are updated so that they // point to Into for (auto &[Neighbor, Tag] : From->Successors) { auto PredBegin = Neighbor->Predecessors.begin(); auto PredEnd = Neighbor->Predecessors.end(); auto It = std::find_if(PredBegin, PredEnd, IsFrom); auto End = std::find_if_not(It, PredEnd, IsFrom); while (It != End) { auto Next = std::next(It); auto Extracted = Neighbor->Predecessors.extract(It); revng_assert(Extracted); Neighbor->Predecessors.insert({ Into, Extracted.value().second }); It = Next; } } // All the successors of all the predecessors of From are updated so that they // point to Into for (auto &[Neighbor, Tag] : From->Predecessors) { auto SuccBegin = Neighbor->Successors.begin(); auto SuccEnd = Neighbor->Successors.end(); auto It = std::find_if(SuccBegin, SuccEnd, IsFrom); auto End = std::find_if_not(It, SuccEnd, IsFrom); while (It != End) { auto Next = std::next(It); auto Extracted = Neighbor->Successors.extract(It); revng_assert(Extracted); Neighbor->Successors.insert({ Into, Extracted.value().second }); It = Next; } } // Merge all the predecessors and successors. { Into->Predecessors.insert(From->Predecessors.begin(), From->Predecessors.end()); Into->Successors.insert(From->Successors.begin(), From->Successors.end()); } // Remove self-references from predecessors and successors. { const auto RemoveSelfEdges = [IsFrom, IsInto](auto &NeighborsSet) { auto It = NeighborsSet.begin(); while (It != NeighborsSet.end()) { auto Next = std::next(It); if (IsInto(*It) or IsFrom(*It)) NeighborsSet.erase(It); It = Next; } }; RemoveSelfEdges(Into->Predecessors); RemoveSelfEdges(Into->Successors); } } static Logger<> MergeLog("dla-merge-nodes"); using LayoutTypeSystemNodePtrVec = std::vector; void LayoutTypeSystem::mergeNodes(const LayoutTypeSystemNodePtrVec &ToMerge) { revng_assert(ToMerge.size() > 1ULL); LayoutTypeSystemNode *Into = ToMerge[0]; const unsigned IntoID = Into->ID; for (LayoutTypeSystemNode *From : llvm::drop_begin(ToMerge, 1)) { revng_assert(From != Into); revng_log(MergeLog, "Merging: " << From->ID << " Into: " << Into->ID); EqClasses.join(IntoID, From->ID); fixPredSucc(From, Into); Into->InterferingInfo = Unknown; // Remove From from Layouts bool Erased = Layouts.erase(From); revng_assert(Erased); From->~LayoutTypeSystemNode(); NodeAllocator.Deallocate(From); } } void LayoutTypeSystem::removeNode(LayoutTypeSystemNode *ToRemove) { // Join the node's eq class with the removed class EqClasses.remove(ToRemove->ID); revng_log(MergeLog, "Removing " << ToRemove->ID << "\n"); const auto IsToRemove = [ToRemove](const LayoutTypeSystemNode::Link &L) { return L.first == ToRemove; }; for (auto &[Neighbor, Tag] : ToRemove->Successors) { auto PredBegin = Neighbor->Predecessors.begin(); auto PredEnd = Neighbor->Predecessors.end(); auto It = std::find_if(PredBegin, PredEnd, IsToRemove); auto End = std::find_if_not(It, PredEnd, IsToRemove); Neighbor->Predecessors.erase(It, End); } for (auto &[Neighbor, Tag] : ToRemove->Predecessors) { auto SuccBegin = Neighbor->Successors.begin(); auto SuccEnd = Neighbor->Successors.end(); auto It = std::find_if(SuccBegin, SuccEnd, IsToRemove); auto End = std::find_if_not(It, SuccEnd, IsToRemove); Neighbor->Successors.erase(It, End); } bool Erased = Layouts.erase(ToRemove); revng_assert(Erased); ToRemove->~LayoutTypeSystemNode(); NodeAllocator.Deallocate(ToRemove); } static void moveEdgesWithoutSumming(LayoutTypeSystemNode *OldSrc, LayoutTypeSystemNode *NewSrc, LayoutTypeSystemNode *Tgt) { // First, move successor edges from OldSrc to NewSrc { const auto IsTgt = [Tgt](const LayoutTypeSystemNode::Link &L) { return L.first == Tgt; }; auto &OldSucc = OldSrc->Successors; auto &NewSucc = NewSrc->Successors; auto OldSuccEnd = OldSucc.end(); auto OldToTgtIt = std::find_if(OldSucc.begin(), OldSuccEnd, IsTgt); auto OldToTgtEnd = std::find_if_not(OldToTgtIt, OldSuccEnd, IsTgt); // Here we can move the edge descriptors directly to NewSucc, because we // don't need to update the offset. while (OldToTgtIt != OldToTgtEnd) { auto Next = std::next(OldToTgtIt); NewSucc.insert(OldSucc.extract(OldToTgtIt)); OldToTgtIt = Next; } } // Then, move predecessor edges from OldSrc to NewSrc { const auto IsOldSrc = [OldSrc](const LayoutTypeSystemNode::Link &L) { return L.first == OldSrc; }; auto &TgtPred = Tgt->Predecessors; auto TgtPredEnd = TgtPred.end(); auto TgtToOldIt = std::find_if(TgtPred.begin(), TgtPredEnd, IsOldSrc); auto TgtToOldEnd = std::find_if_not(TgtToOldIt, TgtPredEnd, IsOldSrc); // Here we can extract, the edge descriptors, update they key (representing // the predecessor) and re-insert them, becasue we don't need to change the // offset. while (TgtToOldIt != TgtToOldEnd) { auto Next = std::next(TgtToOldIt); auto OldPredEdge = TgtPred.extract(TgtToOldIt); OldPredEdge.value().first = NewSrc; TgtPred.insert(std::move(OldPredEdge)); TgtToOldIt = Next; } } } void LayoutTypeSystem::moveEdges(LayoutTypeSystemNode *OldSrc, LayoutTypeSystemNode *NewSrc, LayoutTypeSystemNode *Tgt, int64_t OffsetToSum) { if (not OldSrc or not NewSrc or not Tgt) return; if (not OffsetToSum) return moveEdgesWithoutSumming(OldSrc, NewSrc, Tgt); // First, move successor edges from OldSrc to NewSrc { const auto IsTgt = [Tgt](const LayoutTypeSystemNode::Link &L) { return L.first == Tgt; }; auto &OldSucc = OldSrc->Successors; auto OldSuccEnd = OldSucc.end(); auto OldToTgtIt = std::find_if(OldSucc.begin(), OldSuccEnd, IsTgt); auto OldToTgtEnd = std::find_if_not(OldToTgtIt, OldSuccEnd, IsTgt); // Add new instance links with adjusted offsets from NewSrc to Tgt. // Using the addInstanceLink methods already marks injects NewSrc among the // predecessors of Tgt, so after this we only need to remove OldSrc from // Tgt's predecessors and we're done. while (OldToTgtIt != OldToTgtEnd) { auto Next = std::next(OldToTgtIt); auto OldSuccEdge = OldSucc.extract(OldToTgtIt); const TypeLinkTag *EdgeTag = OldSuccEdge.value().second; switch (EdgeTag->getKind()) { case TypeLinkTag::LK_Inheritance: { revng_assert(OffsetToSum > 0LL); addInstanceLink(NewSrc, Tgt, OffsetExpression(OffsetToSum)); } break; case TypeLinkTag::LK_Instance: { OffsetExpression NewOE = EdgeTag->getOffsetExpr(); NewOE.Offset += OffsetToSum; revng_assert(NewOE.Offset >= 0LL); addInstanceLink(NewSrc, Tgt, std::move(NewOE)); } break; case TypeLinkTag::LK_Equality: default: revng_unreachable("unexpected edge kind"); } OldToTgtIt = Next; } } // Then, remove all the remaining info in Tgt that represent the fact that // OldSrc was a predecessor. { const auto IsOldSrc = [OldSrc](const LayoutTypeSystemNode::Link &L) { return L.first == OldSrc; }; auto &TgtPred = Tgt->Predecessors; auto TgtPredEnd = TgtPred.end(); auto TgtToOldIt = std::find_if(TgtPred.begin(), TgtPredEnd, IsOldSrc); auto TgtToOldEnd = std::find_if_not(TgtToOldIt, TgtPredEnd, IsOldSrc); TgtPred.erase(TgtToOldIt, TgtToOldEnd); } } static Logger<> VerifyDLALog("dla-verify-strict"); bool LayoutTypeSystem::verifyConsistency() const { for (LayoutTypeSystemNode *NodePtr : Layouts) { if (not NodePtr) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } // Check that predecessors and successors are consistent for (auto &P : NodePtr->Predecessors) { if (P.first == nullptr) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } // same edge with same tag auto It = P.first->Successors.find({ NodePtr, P.second }); if (It == P.first->Successors.end()) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } for (auto &P : NodePtr->Successors) { if (P.first == nullptr) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } // same edge with same tag auto It = P.first->Predecessors.find({ NodePtr, P.second }); if (It == P.first->Predecessors.end()) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } // Check that there are no self-edges for (auto &P : NodePtr->Predecessors) { LayoutTypeSystemNode *Pred = P.first; if (Pred == NodePtr) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } for (auto &P : NodePtr->Successors) { LayoutTypeSystemNode *Succ = P.first; if (Succ == NodePtr) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } } return true; } bool LayoutTypeSystem::verifyDAG() const { if (not verifyConsistency()) return false; if (not verifyInheritanceDAG()) return false; if (not verifyInstanceDAG()) return false; std::set SCCHeads; // A graph is a DAG if and only if all its strongly connected components have // size 1 std::set Visited; for (const auto &Node : llvm::nodes(this)) { revng_assert(Node != nullptr); if (Visited.count(Node)) continue; auto I = scc_begin(Node); auto E = scc_end(Node); for (; I != E; ++I) { Visited.insert(I->begin(), I->end()); if (I.hasCycle()) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } } return true; } bool LayoutTypeSystem::verifyInheritanceDAG() const { if (not verifyConsistency()) return false; // A graph is a DAG if and only if all its strongly connected components have // size 1 std::set Visited; for (const auto &Node : llvm::nodes(this)) { revng_assert(Node != nullptr); if (Visited.count(Node)) continue; using GraphNodeT = const LayoutTypeSystemNode *; using InheritanceNodeT = EdgeFilteredGraph; auto I = scc_begin(InheritanceNodeT(Node)); auto E = scc_end(InheritanceNodeT(Node)); for (; I != E; ++I) { Visited.insert(I->begin(), I->end()); if (I.hasCycle()) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } } return true; } bool LayoutTypeSystem::verifyInstanceDAG() const { if (not verifyConsistency()) return false; // A graph is a DAG if and only if all its strongly connected components have // size 1 std::set Visited; for (const auto &Node : llvm::nodes(this)) { revng_assert(Node != nullptr); if (Visited.count(Node)) continue; using GraphNodeT = const LayoutTypeSystemNode *; using InstanceNodeT = EdgeFilteredGraph; auto I = scc_begin(InstanceNodeT(Node)); auto E = scc_end(InstanceNodeT(Node)); for (; I != E; ++I) { Visited.insert(I->begin(), I->end()); if (I.hasCycle()) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } } return true; } bool LayoutTypeSystem::verifyNoEquality() const { if (not verifyConsistency()) return false; for (const auto &Node : llvm::nodes(this)) { using LTSN = LayoutTypeSystemNode; for (const auto &Edge : llvm::children_edges(Node)) { if (isEqualityEdge(Edge)) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } } return true; } bool LayoutTypeSystem::verifyLeafs() const { for (const auto &Node : llvm::nodes(this)) { if (isLeaf(Node) and Node->Size == 0) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } return true; } bool LayoutTypeSystem::verifyInheritanceTree() const { using GraphNodeT = const LayoutTypeSystemNode *; using InheritanceNodeT = EdgeFilteredGraph; using GT = GraphTraits; for (GraphNodeT Node : llvm::nodes(this)) { auto Beg = GT::child_begin(Node); auto End = GT::child_end(Node); if ((Beg != End) and (std::next(Beg) != End)) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } return true; } bool LayoutTypeSystem::verifyConflicts() const { using GraphNodeT = const LayoutTypeSystemNode *; using LinkT = const LayoutTypeSystemNode::Link; for (GraphNodeT Node : llvm::nodes(this)) { for (auto &Succ : Node->Successors) { auto HasSameSucc = [&Succ](const LinkT &L2) { return isInstanceOff0Edge(L2) and (Succ.first == L2.first); }; if (isInheritanceEdge(Succ) and llvm::any_of(Node->Successors, HasSameSucc)) { if (VerifyDLALog.isEnabled()) revng_check(false); return false; } } } return true; } unsigned VectEqClasses::growBy1() { ++NElems; grow(NElems); return NElems; } void VectEqClasses::remove(const unsigned A) { if (RemovedID) join(A, *RemovedID); else RemovedID = A; } bool VectEqClasses::isRemoved(const unsigned ID) const { // No removed nodes if (not RemovedID) return false; // Uncompressed map if (getNumClasses() == 0) return (findLeader(ID) == findLeader(*RemovedID)); // Compressed map unsigned ElementEqClass = lookupEqClass(ID); unsigned RemovedEqClass = lookupEqClass(*RemovedID); return (ElementEqClass == RemovedEqClass); } std::optional VectEqClasses::getEqClassID(const unsigned ID) const { unsigned EqID = lookupEqClass(ID); bool IsRemoved = (RemovedID) ? lookupEqClass(*RemovedID) == EqID : false; if (IsRemoved) return {}; return EqID; } std::vector VectEqClasses::computeEqClass(const unsigned ElemID) const { std::vector EqClass; for (unsigned OtherID = 0; OtherID < NElems; OtherID++) if (haveSameEqClass(ElemID, OtherID)) EqClass.push_back(OtherID); return EqClass; } bool VectEqClasses::haveSameEqClass(unsigned ID1, unsigned ID2) const { // Uncompressed map if (getNumClasses() == 0) return findLeader(ID1) == findLeader(ID2); // Compressed map return lookupEqClass(ID1) == lookupEqClass(ID2); } void TSDebugPrinter::printNodeContent(const LayoutTypeSystem &TS, const LayoutTypeSystemNode *N, llvm::raw_fd_ostream &File) const { auto EqClasses = TS.getEqClasses(); File << DoRet; if (EqClasses.isRemoved(N->ID)) File << "Removed" << DoRet; File << "Equivalence Class: ["; for (auto ID : EqClasses.computeEqClass(N->ID)) File << ID << ", "; File << "]" << DoRet; } } // end namespace dla