Revert "Add -strip-nonlinetable-debuginfo capability"

This reverts commit r283473.

Reverted until review is completed.

llvm-svn: 283478

Author: milseman

llvm/include/llvm/IR/DebugInfo.h

@@ -44,18 +44,6 @@ DISubprogram *getDISubprogram(const MDNode *Scope);
 bool StripDebugInfo(Module &M);
 bool stripDebugInfo(Function &F);
 
-/// Downgrade the debug info in a module to contain only line table information.
-///
-/// In order to convert debug info to what -gline-tables-only would have
-/// created, this does the following:
-///   1) Delete all debug intrinsics.
-///   2) Delete all non-CU named metadata debug info nodes.
-///   3) Create new DebugLocs for each instruction.
-///   4) Create a new CU debug info, and similarly for every metadata node
-///      that's reachable from the CU debug info.
-///   All debug type metadata nodes are unreachable and garbage collected.
-bool stripNonLineTableDebugInfo(Module &M);
-
 /// \brief Return Debug Info Metadata Version by checking module flags.
 unsigned getDebugMetadataVersionFromModule(const Module &M);
 

llvm/include/llvm/InitializePasses.h

@@ -328,7 +328,6 @@ void initializeStripDeadDebugInfoPass(PassRegistry&);
 void initializeStripDeadPrototypesLegacyPassPass(PassRegistry&);
 void initializeStripDebugDeclarePass(PassRegistry&);
 void initializeStripNonDebugSymbolsPass(PassRegistry&);
-void initializeStripNonLineTableDebugInfoPass(PassRegistry&);
 void initializeStripSymbolsPass(PassRegistry&);
 void initializeStructurizeCFGPass(PassRegistry&);
 void initializeTailCallElimPass(PassRegistry&);

llvm/include/llvm/Transforms/IPO.h

@@ -43,10 +43,6 @@ ModulePass *createStripSymbolsPass(bool OnlyDebugInfo = false);
 //
 ModulePass *createStripNonDebugSymbolsPass();
 
-/// This function returns a new pass that downgrades the debug info in the
-/// module to line tables only.
-ModulePass *createStripNonLineTableDebugInfoPass();
-
 //===----------------------------------------------------------------------===//
 //
 // These pass removes llvm.dbg.declare intrinsics.

llvm/lib/IR/DebugInfo.cpp

@@ -287,315 +287,6 @@ bool llvm::StripDebugInfo(Module &M) {
   return Changed;
 }
 
-namespace {
-
-/// Helper class to downgrade -g metadata to -gline-tables-only metadata.
-class DebugTypeInfoRemoval {
-  DenseMap<Metadata *, Metadata *> Replacements;
-
-public:
-  /// The (void)() type.
-  MDNode *EmptySubroutineType;
-
-private:
-  /// Remember what linkage name we originally had before stripping. If we end
-  /// up making two subprograms identical who originally had different linkage
-  /// names, then we need to make one of them distinct, to avoid them getting
-  /// uniqued. Maps the new node to the old linkage name.
-  DenseMap<DISubprogram *, StringRef> NewToLinkageName;
-
-  // TODO: Remember the distinct subprogram we created for a given linkage name,
-  // so that we can continue to unique whenever possible. Map <newly created
-  // node, old linkage name> to the first (possibly distinct) mdsubprogram
-  // created for that combination. This is not strictly needed for correctness,
-  // but can cut down on the number of MDNodes and let us diff cleanly with the
-  // output of -gline-tables-only.
-
-public:
-  DebugTypeInfoRemoval(LLVMContext &C)
-      : EmptySubroutineType(DISubroutineType::get(C, DINode::FlagZero, 0,
-                                                  MDNode::get(C, {}))) {}
-
-  Metadata *map(Metadata *M) {
-    if (!M)
-      return nullptr;
-    if (Replacements.count(M))
-      return Replacements.lookup(M);
-
-    return M;
-  }
-  MDNode *mapNode(Metadata *N) { return dyn_cast_or_null<MDNode>(map(N)); }
-
-  /// Recursively remap N and all its referenced children. Does a DF post-order
-  /// traversal, so as to remap bottoms up.
-  void traverseAndRemap(MDNode *N) { traverse(N); }
-
-private:
-  // Create a new DISubprogram, to replace the one given.
-  DISubprogram *getReplacementSubprogram(DISubprogram *MDS) {
-    auto *FileAndScope = cast_or_null<DIFile>(map(MDS->getFile()));
-    StringRef LinkageName = MDS->getName().empty() ? MDS->getLinkageName() : "";
-    DISubprogram *Declaration = nullptr;
-    auto *Type = cast_or_null<DISubroutineType>(map(MDS->getType()));
-    DITypeRef ContainingType(map(MDS->getContainingType()));
-    auto *Unit = cast_or_null<DICompileUnit>(map(MDS->getUnit()));
-    auto Variables = nullptr;
-    auto TemplateParams = nullptr;
-
-    // Make a distinct DISubprogram, for situations that warrent it.
-    auto distinctMDSubprogram = [&]() {
-      return DISubprogram::getDistinct(
-          MDS->getContext(), FileAndScope, MDS->getName(), LinkageName,
-          FileAndScope, MDS->getLine(), Type, MDS->isLocalToUnit(),
-          MDS->isDefinition(), MDS->getScopeLine(), ContainingType,
-          MDS->getVirtuality(), MDS->getVirtualIndex(),
-          MDS->getThisAdjustment(), MDS->getFlags(), MDS->isOptimized(), Unit,
-          TemplateParams, Declaration, Variables);
-    };
-
-    if (MDS->isDistinct())
-      return distinctMDSubprogram();
-
-    auto *NewMDS = DISubprogram::get(
-        MDS->getContext(), FileAndScope, MDS->getName(), LinkageName,
-        FileAndScope, MDS->getLine(), Type, MDS->isLocalToUnit(),
-        MDS->isDefinition(), MDS->getScopeLine(), ContainingType,
-        MDS->getVirtuality(), MDS->getVirtualIndex(), MDS->getThisAdjustment(),
-        MDS->getFlags(), MDS->isOptimized(), Unit, TemplateParams, Declaration,
-        Variables);
-
-    StringRef OldLinkageName = MDS->getLinkageName();
-
-    // See if we need to make a distinct one.
-    auto OrigLinkage = NewToLinkageName.find(NewMDS);
-    if (OrigLinkage != NewToLinkageName.end()) {
-      if (OrigLinkage->second == OldLinkageName)
-        // We're good.
-        return NewMDS;
-
-      // Otherwise, need to make a distinct one.
-      // TODO: Query the map to see if we already have one.
-      return distinctMDSubprogram();
-    }
-
-    NewToLinkageName.insert({NewMDS, MDS->getLinkageName()});
-    return NewMDS;
-  }
-
-  /// Create a new compile unit, to replace the one given
-  DICompileUnit *getReplacementCU(DICompileUnit *CU) {
-    // Drop skeleton CUs.
-    if (CU->getDWOId())
-      return nullptr;
-
-    auto *File = cast_or_null<DIFile>(map(CU->getFile()));
-    MDTuple *EnumTypes = nullptr;
-    MDTuple *RetainedTypes = nullptr;
-    MDTuple *GlobalVariables = nullptr;
-    MDTuple *ImportedEntities = nullptr;
-    return DICompileUnit::getDistinct(
-        CU->getContext(), CU->getSourceLanguage(), File, CU->getProducer(),
-        CU->isOptimized(), CU->getFlags(), CU->getRuntimeVersion(),
-        CU->getSplitDebugFilename(), DICompileUnit::LineTablesOnly, EnumTypes,
-        RetainedTypes, GlobalVariables, ImportedEntities, CU->getMacros(),
-        CU->getDWOId(), CU->getSplitDebugInlining());
-  }
-
-  DILocation *getReplacementMDLocation(DILocation *MLD) {
-    auto *Scope = map(MLD->getScope());
-    auto *InlinedAt = map(MLD->getInlinedAt());
-    if (MLD->isDistinct())
-      return DILocation::getDistinct(MLD->getContext(), MLD->getLine(),
-                                     MLD->getColumn(), Scope, InlinedAt);
-    return DILocation::get(MLD->getContext(), MLD->getLine(), MLD->getColumn(),
-                           Scope, InlinedAt);
-  }
-
-  /// Create a new generic MDNode, to replace the one given
-  MDNode *getReplacementMDNode(MDNode *N) {
-    SmallVector<Metadata *, 8> Ops;
-    Ops.reserve(N->getNumOperands());
-    for (auto &I : N->operands())
-      if (I)
-        Ops.push_back(map(I));
-    auto *Ret = MDNode::get(N->getContext(), Ops);
-    return Ret;
-  }
-
-  /// Attempt to re-map N to a newly created node.
-  void remap(MDNode *N) {
-    if (Replacements.count(N))
-      return;
-
-    auto doRemap = [&](MDNode *N) -> MDNode * {
-      if (!N)
-        return nullptr;
-      if (auto *MDSub = dyn_cast<DISubprogram>(N)) {
-        remap(MDSub->getUnit());
-        return getReplacementSubprogram(MDSub);
-      }
-      if (isa<DISubroutineType>(N))
-        return EmptySubroutineType;
-      if (auto *CU = dyn_cast<DICompileUnit>(N))
-        return getReplacementCU(CU);
-      if (isa<DIFile>(N))
-        return N;
-      if (auto *MDLB = dyn_cast<DILexicalBlockBase>(N))
-        // Remap to our referenced scope (recursively).
-        return mapNode(MDLB->getScope());
-      if (auto *MLD = dyn_cast<DILocation>(N))
-        return getReplacementMDLocation(MLD);
-
-      // Otherwise, if we see these, just drop them now. Not strictly necessary,
-      // but this speeds things up a little.
-      if (isa<DINode>(N))
-        return nullptr;
-
-      return getReplacementMDNode(N);
-    };
-    Replacements[N] = doRemap(N);
-  }
-
-  /// Do the remapping traversal.
-  void traverse(MDNode *);
-};
-
-} // Anonymous namespace.
-
-void DebugTypeInfoRemoval::traverse(MDNode *N) {
-  if (!N || Replacements.count(N))
-    return;
-
-  // To avoid cycles, as well as for efficiency sake, we will sometimes prune
-  // parts of the graph.
-  auto prune = [](MDNode *Parent, MDNode *Child) {
-    if (auto *MDS = dyn_cast<DISubprogram>(Parent))
-      return Child == MDS->getVariables().get();
-    return false;
-  };
-
-  SmallVector<MDNode *, 16> ToVisit;
-  DenseSet<MDNode *> Opened;
-
-  // Visit each node starting at N in post order, and map them.
-  ToVisit.push_back(N);
-  while (!ToVisit.empty()) {
-    auto *N = ToVisit.back();
-    auto Result = Opened.insert(N);
-    if (!Result.second) {
-      // Close it.
-      remap(N);
-      ToVisit.pop_back();
-      continue;
-    }
-    for (auto &I : N->operands())
-      if (auto *MDN = dyn_cast_or_null<MDNode>(I))
-        if (!Opened.count(MDN) && !Replacements.count(MDN) && !prune(N, MDN) &&
-            !isa<DICompileUnit>(MDN))
-          ToVisit.push_back(MDN);
-  }
-}
-
-bool llvm::stripNonLineTableDebugInfo(Module &M) {
-  bool Changed = false;
-
-  // First off, delete the debug intrinsics.
-  if (Function *Declare = M.getFunction("llvm.dbg.declare")) {
-    while (!Declare->use_empty()) {
-      auto *DDI = cast<DbgDeclareInst>(Declare->user_back());
-      DDI->eraseFromParent();
-    }
-    Declare->eraseFromParent();
-    Changed = true;
-  }
-  if (Function *DbgVal = M.getFunction("llvm.dbg.value")) {
-    while (!DbgVal->use_empty()) {
-      auto *DVI = cast<DbgValueInst>(DbgVal->user_back());
-      DVI->eraseFromParent();
-    }
-    DbgVal->eraseFromParent();
-    Changed = true;
-  }
-
-  // Delete non-CU debug info named metadata nodes.
-  for (auto NMI = M.named_metadata_begin(), NME = M.named_metadata_end();
-       NMI != NME;) {
-    NamedMDNode *NMD = &*NMI;
-    ++NMI;
-    // Specifically keep dbg.cu around.
-    if (NMD->getName() == "llvm.dbg.cu")
-      continue;
-  }
-
-  // Drop all dbg attachments from global variables.
-  for (auto &GV : M.globals())
-    GV.getContext().pImpl->GlobalObjectMetadata[&GV].erase(LLVMContext::MD_dbg);
-
-  DebugTypeInfoRemoval Mapper(M.getContext());
-
-  // Rewrite the DebugLocs to be equivalent to what
-  // -gline-tables-only would have created.
-  for (auto &F : M) {
-    auto *SP = F.getSubprogram();
-    if (SP) {
-      Mapper.traverseAndRemap(SP);
-      auto *NewSP = cast<DISubprogram>(Mapper.mapNode(SP));
-      Changed |= SP != NewSP;
-      F.setSubprogram(NewSP);
-    }
-    for (auto &BB : F) {
-      for (auto &I : BB) {
-        if (I.getDebugLoc() == DebugLoc())
-          continue;
-
-        // Make a replacement.
-        auto &DL = I.getDebugLoc();
-        auto *Scope = DL.getScope();
-        auto *InlinedAt = DL.getInlinedAt();
-
-        // Remap scope.
-        if (Scope) {
-          Mapper.traverseAndRemap(Scope);
-          auto *NewScope = Mapper.mapNode(Scope);
-          Changed |= Scope != NewScope;
-          Scope = NewScope;
-        }
-
-        // Remap inlinedAt.
-        if (InlinedAt) {
-          Mapper.traverseAndRemap(InlinedAt);
-          auto *NewIA = Mapper.mapNode(InlinedAt);
-          Changed |= InlinedAt != NewIA;
-          InlinedAt = cast_or_null<DILocation>(NewIA);
-        }
-
-        I.setDebugLoc(
-            DebugLoc::get(DL.getLine(), DL.getCol(), Scope, InlinedAt));
-      }
-    }
-  }
-
-  // Create a new llvm.dbg.cu, which is equivalent to the one
-  // -gline-tables-only would have created.
-  for (auto &NMD : M.getNamedMDList()) {
-    SmallVector<MDNode *, 8> Ops;
-    for (MDNode *Op : NMD.operands()) {
-      Mapper.traverseAndRemap(Op);
-      auto *NewOp = Mapper.mapNode(Op);
-      Changed |= NewOp != Op;
-      Ops.push_back(NewOp);
-    }
-
-    if (Changed) {
-      NMD.dropAllReferences();
-      for (auto *Op : Ops)
-        if (Op)
-          NMD.addOperand(Op);
-    }
-  }
-  return Changed;
-}
-
 unsigned llvm::getDebugMetadataVersionFromModule(const Module &M) {
   if (auto *Val = mdconst::dyn_extract_or_null<ConstantInt>(
           M.getModuleFlag("Debug Info Version")))

llvm/lib/Transforms/Utils/CMakeLists.txt

@@ -41,7 +41,6 @@ add_llvm_library(LLVMTransformUtils
   SimplifyInstructions.cpp
   SimplifyLibCalls.cpp
   SplitModule.cpp
-  StripNonLineTableDebugInfo.cpp
   SymbolRewriter.cpp
   UnifyFunctionExitNodes.cpp
   Utils.cpp