llvm/lib/IR/LLVMContextImpl.cpp

   1 //===- LLVMContextImpl.cpp - Implement LLVMContextImpl --------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //  This file implements the opaque LLVMContextImpl.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "LLVMContextImpl.h"
  14 #include "llvm/ADT/SetVector.h"
  15 #include "llvm/IR/Module.h"
  16 #include "llvm/IR/OptBisect.h"
  17 #include "llvm/IR/Type.h"
  18 #include "llvm/Support/CommandLine.h"
  19 #include "llvm/Support/ManagedStatic.h"
  20 #include <cassert>
  21 #include <utility>
  22
  23 using namespace llvm;
  24
  25 static cl::opt<bool>
  26     ForceOpaquePointersCL("force-opaque-pointers",
  27                           cl::desc("Force all pointers to be opaque pointers"),
  28                           cl::init(false));
  29
  30 LLVMContextImpl::LLVMContextImpl(LLVMContext &C)
  31     : DiagHandler(std::make_unique<DiagnosticHandler>()),
  32       VoidTy(C, Type::VoidTyID), LabelTy(C, Type::LabelTyID),
  33       HalfTy(C, Type::HalfTyID), BFloatTy(C, Type::BFloatTyID),
  34       FloatTy(C, Type::FloatTyID), DoubleTy(C, Type::DoubleTyID),
  35       MetadataTy(C, Type::MetadataTyID), TokenTy(C, Type::TokenTyID),
  36       X86_FP80Ty(C, Type::X86_FP80TyID), FP128Ty(C, Type::FP128TyID),
  37       PPC_FP128Ty(C, Type::PPC_FP128TyID), X86_MMXTy(C, Type::X86_MMXTyID),
  38       X86_AMXTy(C, Type::X86_AMXTyID), Int1Ty(C, 1), Int8Ty(C, 8),
  39       Int16Ty(C, 16), Int32Ty(C, 32), Int64Ty(C, 64), Int128Ty(C, 128),
  40       ForceOpaquePointers(ForceOpaquePointersCL) {}
  41
  42 LLVMContextImpl::~LLVMContextImpl() {
  43   // NOTE: We need to delete the contents of OwnedModules, but Module's dtor
  44   // will call LLVMContextImpl::removeModule, thus invalidating iterators into
  45   // the container. Avoid iterators during this operation:
  46   while (!OwnedModules.empty())
  47     delete *OwnedModules.begin();
  48
  49 #ifndef NDEBUG
  50   // Check for metadata references from leaked Values.
  51   for (auto &Pair : ValueMetadata)
  52     Pair.first->dump();
  53   assert(ValueMetadata.empty() && "Values with metadata have been leaked");
  54 #endif
  55
  56   // Drop references for MDNodes.  Do this before Values get deleted to avoid
  57   // unnecessary RAUW when nodes are still unresolved.
  58   for (auto *I : DistinctMDNodes)
  59     I->dropAllReferences();
  60 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
  61   for (auto *I : CLASS##s)                                                     \
  62     I->dropAllReferences();
  63 #include "llvm/IR/Metadata.def"
  64
  65   // Also drop references that come from the Value bridges.
  66   for (auto &Pair : ValuesAsMetadata)
  67     Pair.second->dropUsers();
  68   for (auto &Pair : MetadataAsValues)
  69     Pair.second->dropUse();
  70
  71   // Destroy MDNodes.
  72   for (MDNode *I : DistinctMDNodes)
  73     I->deleteAsSubclass();
  74 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
  75   for (CLASS * I : CLASS##s)                                                   \
  76     delete I;
  77 #include "llvm/IR/Metadata.def"
  78
  79   // Free the constants.
  80   for (auto *I : ExprConstants)
  81     I->dropAllReferences();
  82   for (auto *I : ArrayConstants)
  83     I->dropAllReferences();
  84   for (auto *I : StructConstants)
  85     I->dropAllReferences();
  86   for (auto *I : VectorConstants)
  87     I->dropAllReferences();
  88   ExprConstants.freeConstants();
  89   ArrayConstants.freeConstants();
  90   StructConstants.freeConstants();
  91   VectorConstants.freeConstants();
  92   InlineAsms.freeConstants();
  93
  94   CAZConstants.clear();
  95   CPNConstants.clear();
  96   UVConstants.clear();
  97   PVConstants.clear();
  98   IntConstants.clear();
  99   FPConstants.clear();
 100   CDSConstants.clear();
 101
 102   // Destroy attribute node lists.
 103   for (FoldingSetIterator<AttributeSetNode> I = AttrsSetNodes.begin(),
 104          E = AttrsSetNodes.end(); I != E; ) {
 105     FoldingSetIterator<AttributeSetNode> Elem = I++;
 106     delete &*Elem;
 107   }
 108
 109   // Destroy MetadataAsValues.
 110   {
 111     SmallVector<MetadataAsValue *, 8> MDVs;
 112     MDVs.reserve(MetadataAsValues.size());
 113     for (auto &Pair : MetadataAsValues)
 114       MDVs.push_back(Pair.second);
 115     MetadataAsValues.clear();
 116     for (auto *V : MDVs)
 117       delete V;
 118   }
 119
 120   // Destroy ValuesAsMetadata.
 121   for (auto &Pair : ValuesAsMetadata)
 122     delete Pair.second;
 123 }
 124
 125 void LLVMContextImpl::dropTriviallyDeadConstantArrays() {
 126   SmallSetVector<ConstantArray *, 4> WorkList;
 127
 128   // When ArrayConstants are of substantial size and only a few in them are
 129   // dead, starting WorkList with all elements of ArrayConstants can be
 130   // wasteful. Instead, starting WorkList with only elements that have empty
 131   // uses.
 132   for (ConstantArray *C : ArrayConstants)
 133     if (C->use_empty())
 134       WorkList.insert(C);
 135
 136   while (!WorkList.empty()) {
 137     ConstantArray *C = WorkList.pop_back_val();
 138     if (C->use_empty()) {
 139       for (const Use &Op : C->operands()) {
 140         if (auto *COp = dyn_cast<ConstantArray>(Op))
 141           WorkList.insert(COp);
 142       }
 143       C->destroyConstant();
 144     }
 145   }
 146 }
 147
 148 void Module::dropTriviallyDeadConstantArrays() {
 149   Context.pImpl->dropTriviallyDeadConstantArrays();
 150 }
 151
 152 namespace llvm {
 153
 154 /// Make MDOperand transparent for hashing.
 155 ///
 156 /// This overload of an implementation detail of the hashing library makes
 157 /// MDOperand hash to the same value as a \a Metadata pointer.
 158 ///
 159 /// Note that overloading \a hash_value() as follows:
 160 ///
 161 /// \code
 162 ///     size_t hash_value(const MDOperand &X) { return hash_value(X.get()); }
 163 /// \endcode
 164 ///
 165 /// does not cause MDOperand to be transparent.  In particular, a bare pointer
 166 /// doesn't get hashed before it's combined, whereas \a MDOperand would.
 167 static const Metadata *get_hashable_data(const MDOperand &X) { return X.get(); }
 168
 169 } // end namespace llvm
 170
 171 unsigned MDNodeOpsKey::calculateHash(MDNode *N, unsigned Offset) {
 172   unsigned Hash = hash_combine_range(N->op_begin() + Offset, N->op_end());
 173 #ifndef NDEBUG
 174   {
 175     SmallVector<Metadata *, 8> MDs(drop_begin(N->operands(), Offset));
 176     unsigned RawHash = calculateHash(MDs);
 177     assert(Hash == RawHash &&
 178            "Expected hash of MDOperand to equal hash of Metadata*");
 179   }
 180 #endif
 181   return Hash;
 182 }
 183
 184 unsigned MDNodeOpsKey::calculateHash(ArrayRef<Metadata *> Ops) {
 185   return hash_combine_range(Ops.begin(), Ops.end());
 186 }
 187
 188 StringMapEntry<uint32_t> *LLVMContextImpl::getOrInsertBundleTag(StringRef Tag) {
 189   uint32_t NewIdx = BundleTagCache.size();
 190   return &*(BundleTagCache.insert(std::make_pair(Tag, NewIdx)).first);
 191 }
 192
 193 void LLVMContextImpl::getOperandBundleTags(SmallVectorImpl<StringRef> &Tags) const {
 194   Tags.resize(BundleTagCache.size());
 195   for (const auto &T : BundleTagCache)
 196     Tags[T.second] = T.first();
 197 }
 198
 199 uint32_t LLVMContextImpl::getOperandBundleTagID(StringRef Tag) const {
 200   auto I = BundleTagCache.find(Tag);
 201   assert(I != BundleTagCache.end() && "Unknown tag!");
 202   return I->second;
 203 }
 204
 205 SyncScope::ID LLVMContextImpl::getOrInsertSyncScopeID(StringRef SSN) {
 206   auto NewSSID = SSC.size();
 207   assert(NewSSID < std::numeric_limits<SyncScope::ID>::max() &&
 208          "Hit the maximum number of synchronization scopes allowed!");
 209   return SSC.insert(std::make_pair(SSN, SyncScope::ID(NewSSID))).first->second;
 210 }
 211
 212 void LLVMContextImpl::getSyncScopeNames(
 213     SmallVectorImpl<StringRef> &SSNs) const {
 214   SSNs.resize(SSC.size());
 215   for (const auto &SSE : SSC)
 216     SSNs[SSE.second] = SSE.first();
 217 }
 218
 219 /// Gets the OptPassGate for this LLVMContextImpl, which defaults to the
 220 /// singleton OptBisect if not explicitly set.
 221 OptPassGate &LLVMContextImpl::getOptPassGate() const {
 222   if (!OPG)
 223     OPG = &(*OptBisector);
 224   return *OPG;
 225 }
 226
 227 void LLVMContextImpl::setOptPassGate(OptPassGate& OPG) {
 228   this->OPG = &OPG;
 229 }