Add -strip-nonlinetable-debuginfo capability

This adds a new function to DebugInfo.cpp that takes an llvm::Module
as input and removes all debug info metadata that is not directly
needed for line tables, thus effectively stripping all type and
variable information from the module.

The primary motivation for this feature was the bitcode work flow
(cf. http://lists.llvm.org/pipermail/llvm-dev/2016-June/100643.html
for more background). This is not wired up yet, but will be in
subsequent patches.  For testing, the new functionality is exposed to
opt with a -strip-nonlinetable-debuginfo option.

The secondary use-case (and one that works right now!) is as a
reduction pass in bugpoint. I added two new bugpoint options
(-disable-strip-debuginfo and -disable-strip-debug-types) to control
the new features. By default it will first attempt to remove all debug
information, then only the type info, and then proceed to hack at any
remaining MDNodes.

Thanks to Adrian Prantl for stewarding this patch!

llvm-svn: 285094

diff --git a/llvm/include/llvm/IR/DebugInfo.h b/llvm/include/llvm/IR/DebugInfo.h
index 972042432b7b491976fea1a04fc44fe5047dfbff..c110659257de6ec9bad328d38ef513f8f9b53993 100644 (file)
--- a/llvm/include/llvm/IR/DebugInfo.h
+++ b/llvm/include/llvm/IR/DebugInfo.h
@@ -44,6 +44,18 @@ 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);
 

diff --git a/llvm/include/llvm/IR/Metadata.h b/llvm/include/llvm/IR/Metadata.h
index 0ce88829214ab04881870eb9a26e138ad048f7f8..25d4316087ea9f029b8fbd1463ff1f34d393c768 100644 (file)
--- a/llvm/include/llvm/IR/Metadata.h
+++ b/llvm/include/llvm/IR/Metadata.h
@@ -1299,8 +1299,10 @@ public:
   /// \brief Drop all references and remove the node from parent module.
   void eraseFromParent();
 
-  /// \brief Remove all uses and clear node vector.
-  void dropAllReferences();
+  /// Remove all uses and clear node vector.
+  void dropAllReferences() { clearOperands(); }
+  /// Drop all references to this node's operands.
+  void clearOperands();
 
   ~NamedMDNode();
 

diff --git a/llvm/include/llvm/InitializePasses.h b/llvm/include/llvm/InitializePasses.h
index 4020bd5e8023d53b57d154e043396aca2ae0e85a..970343790fe1f66c03a098b9357efd1d8e19e7c0 100644 (file)
--- a/llvm/include/llvm/InitializePasses.h
+++ b/llvm/include/llvm/InitializePasses.h
@@ -330,6 +330,7 @@ void initializeStripDeadDebugInfoPass(PassRegistry&);
 void initializeStripDeadPrototypesLegacyPassPass(PassRegistry&);
 void initializeStripDebugDeclarePass(PassRegistry&);
 void initializeStripNonDebugSymbolsPass(PassRegistry&);
+void initializeStripNonLineTableDebugInfoPass(PassRegistry&);
 void initializeStripSymbolsPass(PassRegistry&);
 void initializeStructurizeCFGPass(PassRegistry&);
 void initializeTailCallElimPass(PassRegistry&);

diff --git a/llvm/include/llvm/Transforms/IPO.h b/llvm/include/llvm/Transforms/IPO.h
index 9ef3881711747802e1cc535dfdc5fd692308b6a9..0d9c1baf1b108f740cbc688c95fdb6f0381cacd5 100644 (file)
--- a/llvm/include/llvm/Transforms/IPO.h
+++ b/llvm/include/llvm/Transforms/IPO.h
@@ -43,6 +43,10 @@ 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.

diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index be00387682fadd383ae1e05e091e4ef98df495c6..7f91b49d82879f2d8681ab3bdfafb6326f8f625e 100644 (file)
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -300,6 +300,299 @@ 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;
+    auto Replacement = Replacements.find(M);
+    if (Replacement != Replacements.end())
+      return Replacement->second;
+
+    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();
+    if (!Opened.insert(N).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.
+  auto RemoveUses = [&](StringRef Name) {
+    if (auto *DbgVal = M.getFunction(Name)) {
+      while (!DbgVal->use_empty())
+        cast<Instruction>(DbgVal->user_back())->eraseFromParent();
+      DbgVal->eraseFromParent();
+      Changed = true;
+    }
+  };
+  RemoveUses("llvm.dbg.declare");
+  RemoveUses("llvm.dbg.value");
+
+  // 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.eraseMetadata(LLVMContext::MD_dbg);
+
+  DebugTypeInfoRemoval Mapper(M.getContext());
+  auto remap = [&](llvm::MDNode *Node) -> llvm::MDNode * {
+    if (!Node)
+      return nullptr;
+    Mapper.traverseAndRemap(Node);
+    auto *NewNode = Mapper.mapNode(Node);
+    Changed |= Node != NewNode;
+    Node = NewNode;
+    return NewNode;
+  };
+
+  // Rewrite the DebugLocs to be equivalent to what
+  // -gline-tables-only would have created.
+  for (auto &F : M) {
+    if (auto *SP = F.getSubprogram()) {
+      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();
+        MDNode *InlinedAt = DL.getInlinedAt();
+        Scope = remap(Scope);
+        InlinedAt = remap(InlinedAt);
+        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())
+      Ops.push_back(remap(Op));
+ 
+    if (!Changed)
+      continue;
+ 
+    NMD.clearOperands();
+    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")))

diff --git a/llvm/lib/IR/Metadata.cpp b/llvm/lib/IR/Metadata.cpp
index 17aa1216b3eed3526d984b0fac894adeda13360b..adc91573a7f87ccbf8f1b7d5efa2850dc73fcfd2 100644 (file)
--- a/llvm/lib/IR/Metadata.cpp
+++ b/llvm/lib/IR/Metadata.cpp
@@ -1054,7 +1054,7 @@ void NamedMDNode::setOperand(unsigned I, MDNode *New) {
 
 void NamedMDNode::eraseFromParent() { getParent()->eraseNamedMetadata(this); }
 
-void NamedMDNode::dropAllReferences() { getNMDOps(Operands).clear(); }
+void NamedMDNode::clearOperands() { getNMDOps(Operands).clear(); }
 
 StringRef NamedMDNode::getName() const { return StringRef(Name); }
 

diff --git a/llvm/lib/Transforms/Utils/CMakeLists.txt b/llvm/lib/Transforms/Utils/CMakeLists.txt
index b5c03ec8006f66fe80f74e13dcb9d12de2357c39..86e5949531b6606f856a5acb3b2400e9bdd03fb3 100644 (file)
--- a/llvm/lib/Transforms/Utils/CMakeLists.txt
+++ b/llvm/lib/Transforms/Utils/CMakeLists.txt
@@ -43,6 +43,7 @@ add_llvm_library(LLVMTransformUtils
   SimplifyInstructions.cpp
   SimplifyLibCalls.cpp
   SplitModule.cpp
+  StripNonLineTableDebugInfo.cpp
   SymbolRewriter.cpp
   UnifyFunctionExitNodes.cpp
   Utils.cpp

diff --git a/llvm/lib/Transforms/Utils/StripNonLineTableDebugInfo.cpp b/llvm/lib/Transforms/Utils/StripNonLineTableDebugInfo.cpp
new file mode 100644 (file)
index 0000000..66dbf33
--- /dev/null
+++ b/llvm/lib/Transforms/Utils/StripNonLineTableDebugInfo.cpp
@@ -0,0 +1,42 @@
+//===- StripNonLineTableDebugInfo.cpp -- Strip parts of Debug Info --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/IPO.h"
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/Pass.h"
+using namespace llvm;
+
+namespace {
+
+/// This pass strips all debug info that is not related line tables.
+/// The result will be the same as if the program where compiled with
+/// -gline-tables-only.
+struct StripNonLineTableDebugInfo : public ModulePass {
+  static char ID; // Pass identification, replacement for typeid
+  StripNonLineTableDebugInfo() : ModulePass(ID) {
+    initializeStripNonLineTableDebugInfoPass(*PassRegistry::getPassRegistry());
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesAll();
+  }
+
+  bool runOnModule(Module &M) override {
+    return llvm::stripNonLineTableDebugInfo(M);
+  }
+};
+}
+
+char StripNonLineTableDebugInfo::ID = 0;
+INITIALIZE_PASS(StripNonLineTableDebugInfo, "strip-nonlinetable-debuginfo",
+                "Strip all debug info except linetables", false, false)
+
+ModulePass *llvm::createStripNonLineTableDebugInfoPass() {
+  return new StripNonLineTableDebugInfo();
+}

diff --git a/llvm/lib/Transforms/Utils/Utils.cpp b/llvm/lib/Transforms/Utils/Utils.cpp
index cfd8551610866f39300f8f8974fa5b7417abefca..7b9de2eadc611381558fe733ba0bcc655b01b67f 100644 (file)
--- a/llvm/lib/Transforms/Utils/Utils.cpp
+++ b/llvm/lib/Transforms/Utils/Utils.cpp
@@ -31,6 +31,7 @@ void llvm::initializeTransformUtils(PassRegistry &Registry) {
   initializeLowerSwitchPass(Registry);
   initializeNameAnonGlobalLegacyPassPass(Registry);
   initializePromoteLegacyPassPass(Registry);
+  initializeStripNonLineTableDebugInfoPass(Registry);
   initializeUnifyFunctionExitNodesPass(Registry);
   initializeInstSimplifierPass(Registry);
   initializeMetaRenamerPass(Registry);

diff --git a/llvm/test/BugPoint/metadata.ll b/llvm/test/BugPoint/metadata.ll
index 1f2f6a901836d6e7c4302520d558be6597199aa7..ac77b9e5a7d1772f6418dfae461a956418315fad 100644 (file)
--- a/llvm/test/BugPoint/metadata.ll
+++ b/llvm/test/BugPoint/metadata.ll
@@ -1,10 +1,22 @@
-; RUN: bugpoint -load %llvmshlibdir/BugpointPasses%shlibext %s -output-prefix %t -bugpoint-crashcalls -silence-passes -disable-namedmd-remove > /dev/null
-; RUN: llvm-dis %t-reduced-simplified.bc -o - | FileCheck %s
 ; REQUIRES: loadable_module
-
+; RUN: bugpoint -load %llvmshlibdir/BugpointPasses%shlibext %s -output-prefix %t -bugpoint-crashcalls -silence-passes -disable-namedmd-remove -disable-strip-debuginfo -disable-strip-debug-types > /dev/null
+; RUN: llvm-dis %t-reduced-simplified.bc -o - | FileCheck %s
+;
+; RUN: bugpoint -load %llvmshlibdir/BugpointPasses%shlibext %s -output-prefix %t-nodebug -bugpoint-crashcalls -silence-passes -disable-namedmd-remove > /dev/null
+; RUN: llvm-dis %t-nodebug-reduced-simplified.bc -o - | FileCheck %s --check-prefix=NODEBUG
+;
+; RUN: bugpoint -load %llvmshlibdir/BugpointPasses%shlibext %s -output-prefix %t-notype -bugpoint-crashcalls -silence-passes -disable-namedmd-remove -disable-strip-debuginfo > /dev/null
+; RUN: llvm-dis %t-notype-reduced-simplified.bc -o - | FileCheck %s --check-prefix=NOTYPE
+;
 ; Bugpoint should keep the call's metadata attached to the call.
 
 ; CHECK: call void @foo(), !dbg ![[LOC:[0-9]+]], !attach ![[CALL:[0-9]+]]
+; NODEBUG: call void @foo(), !attach ![[CALL:[0-9]+]]
+; NOTYPE: call void @foo(), !dbg ![[LOC:[0-9]+]], !attach ![[CALL:[0-9]+]]
+; NODEBUG-NOT: call void @foo(), !attach ![[CALL:[0-9]+]]
+; NOTYPE-NOT: !DIBasicType
+; NOTYPE: !DICompileUnit
+; NOTYPE-NOT: !DIBasicType
 ; CHECK-DAG: ![[LOC]] = !DILocation(line: 104, column: 105, scope: ![[SCOPE:[0-9]+]])
 ; CHECK-DAG: ![[SCOPE]] = distinct !DISubprogram(name: "test",{{.*}}file: ![[FILE:[0-9]+]]
 ; CHECK-DAG: ![[FILE]] = !DIFile(filename: "source.c", directory: "/dir")
@@ -32,7 +44,7 @@ declare void @foo()
 !4 = !{!"filler"}
 
 !8 = distinct !DICompileUnit(language: DW_LANG_C99, file: !15)
-!9 = distinct !DISubprogram(name: "test", file: !15, unit: !8)
+!9 = distinct !DISubprogram(name: "test", file: !15, type: !18, unit: !8)
 !10 = !DILocation(line: 100, column: 101, scope: !9)
 !11 = !DILocation(line: 102, column: 103, scope: !9)
 !12 = !DILocation(line: 104, column: 105, scope: !9)
@@ -41,3 +53,6 @@ declare void @foo()
 !15 = !DIFile(filename: "source.c", directory: "/dir")
 !16 = !{}
 !17 = !{i32 1, !"Debug Info Version", i32 3}
+!18 = !DISubroutineType(types: !19)
+!19 = !{!20, !20}
+!20 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)

diff --git a/llvm/test/BugPoint/named-md.ll b/llvm/test/BugPoint/named-md.ll
index 1fffa2cb978f07e17d0eb6238bb564d5356b6855..1ed34435fbebba40ac8b3c3c59bdf934c86cd7e4 100644 (file)
--- a/llvm/test/BugPoint/named-md.ll
+++ b/llvm/test/BugPoint/named-md.ll
@@ -1,4 +1,4 @@
-; RUN: bugpoint -load %llvmshlibdir/BugpointPasses%shlibext %s -output-prefix %t -bugpoint-crash-too-many-cus -silence-passes > /dev/null
+; RUN: bugpoint -load %llvmshlibdir/BugpointPasses%shlibext %s -output-prefix %t -bugpoint-crash-too-many-cus -silence-passes -disable-strip-debuginfo > /dev/null
 ; RUN: llvm-dis %t-reduced-simplified.bc -o - | FileCheck %s
 ; RUN-DISABLE: bugpoint -disable-namedmd-remove -load %llvmshlibdir/BugpointPasses%shlibext %s -output-prefix %t -bugpoint-crash-too-many-cus -silence-passes > /dev/null
 ; RUN-DISABLE: llvm-dis %t-reduced-simplified.bc -o - | FileCheck %s

diff --git a/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-containingtypes.ll b/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-containingtypes.ll
new file mode 100644 (file)
index 0000000..6c6b499
--- /dev/null
+++ b/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-containingtypes.ll
@@ -0,0 +1,92 @@
+; RUN: opt -S -strip-nonlinetable-debuginfo %s -o %t.ll
+; RUN: cat %t.ll | FileCheck %s
+; RUN: cat %t.ll | FileCheck %s --check-prefix=CHECK-NEG
+;
+; This test provides coverage for setting the containing type of a DISubprogram.
+;
+; Generated an reduced from:
+; struct A {
+;   virtual ~A();
+; };
+; struct B : A {};
+; B b;
+
+source_filename = "t.cpp"
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.12.0"
+
+%struct.B = type { %struct.A }
+%struct.A = type { i32 (...)** }
+
+; CHECK: @b = global
+; CHECK-NOT: !dbg
+@b = global %struct.B zeroinitializer, align 8, !dbg !0
+
+declare void @_ZN1BC2Ev(%struct.B*) unnamed_addr
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #0
+
+; Function Attrs: inlinehint nounwind ssp uwtable
+; CHECK: define
+define linkonce_odr void @_ZN1BC1Ev(%struct.B* %this) unnamed_addr #1 align 2 !dbg !24 {
+entry:
+  %this.addr = alloca %struct.B*, align 8
+  store %struct.B* %this, %struct.B** %this.addr, align 8
+  ; CHECK-NOT: @llvm.dbg.declare
+  call void @llvm.dbg.declare(metadata %struct.B** %this.addr, metadata !29, metadata !31), !dbg !32
+  %this1 = load %struct.B*, %struct.B** %this.addr, align 8
+  ; CHECK: call void @_ZN1BC2Ev(%struct.B* %this1){{.*}} !dbg !
+  call void @_ZN1BC2Ev(%struct.B* %this1) #2, !dbg !33
+  ret void, !dbg !33
+}
+
+attributes #0 = { nounwind readnone }
+attributes #1 = { inlinehint nounwind ssp uwtable }
+attributes #2 = { nounwind }
+
+!llvm.dbg.cu = !{!1}
+!llvm.module.flags = !{!20, !21, !22}
+!llvm.ident = !{!23}
+
+; CHECK-NEG-NOT: !DI{{Basic|Composite|Derived}}Type
+
+!0 = distinct !DIGlobalVariable(name: "b", scope: !1, file: !2, line: 5, type: !5, isLocal: false, isDefinition: true)
+!1 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !2, producer: "clang version 4.0.0 (trunk 282583) (llvm/trunk 282611)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !3, globals: !4)
+!2 = !DIFile(filename: "t.cpp", directory: "/")
+!3 = !{}
+!4 = !{!0}
+!5 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "B", file: !2, line: 4, size: 64, align: 64, elements: !6, vtableHolder: !8, identifier: "_ZTS1B")
+!6 = !{!7}
+!7 = !DIDerivedType(tag: DW_TAG_inheritance, scope: !5, baseType: !8)
+!8 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "A", file: !2, line: 1, size: 64, align: 64, elements: !9, vtableHolder: !8, identifier: "_ZTS1A")
+!9 = !{!10, !16}
+!10 = !DIDerivedType(tag: DW_TAG_member, name: "_vptr$A", scope: !2, file: !2, baseType: !11, size: 64, flags: DIFlagArtificial)
+!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64)
+!12 = !DIDerivedType(tag: DW_TAG_pointer_type, name: "__vtbl_ptr_type", baseType: !13, size: 64)
+!13 = !DISubroutineType(types: !14)
+!14 = !{!15}
+!15 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+; Only referenced by the type system.
+; CHECK-NEG-NOT: !DISubprogram(name: "~A"
+!16 = !DISubprogram(name: "~A", scope: !8, file: !2, line: 2, type: !17, isLocal: false, isDefinition: false, scopeLine: 2, containingType: !8, virtuality: DW_VIRTUALITY_virtual, virtualIndex: 0, flags: DIFlagPrototyped, isOptimized: false)
+!17 = !DISubroutineType(types: !18)
+!18 = !{null, !19}
+!19 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !8, size: 64, align: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
+!20 = !{i32 2, !"Dwarf Version", i32 4}
+!21 = !{i32 2, !"Debug Info Version", i32 3}
+!22 = !{i32 1, !"PIC Level", i32 2}
+!23 = !{!"clang version 4.0.0 (trunk 282583) (llvm/trunk 282611)"}
+; CHECK: !DISubprogram(name: "B", scope: ![[FILE:.*]], file: ![[FILE]],
+; CHECK-NOT: containingType:
+!24 = distinct !DISubprogram(name: "B", linkageName: "_ZN1BC1Ev", scope: !5, file: !2, line: 4, type: !25, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagArtificial | DIFlagPrototyped, isOptimized: false, unit: !1, declaration: !28, variables: !3)
+!25 = !DISubroutineType(types: !26)
+!26 = !{null, !27}
+!27 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !5, size: 64, align: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
+; CHECK-NEG-NOT: !DISubprogram(name: "B", {{.*}}, isDefinition: false
+!28 = !DISubprogram(name: "B", scope: !5, type: !25, isLocal: false, isDefinition: false, flags: DIFlagArtificial | DIFlagPrototyped, isOptimized: false)
+!29 = !DILocalVariable(name: "this", arg: 1, scope: !24, type: !30, flags: DIFlagArtificial | DIFlagObjectPointer)
+!30 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !5, size: 64, align: 64)
+!31 = !DIExpression()
+!32 = !DILocation(line: 0, scope: !24)
+!33 = !DILocation(line: 4, column: 8, scope: !24)

diff --git a/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-cus.ll b/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-cus.ll
new file mode 100644 (file)
index 0000000..f7ffdf9
--- /dev/null
+++ b/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-cus.ll
@@ -0,0 +1,24 @@
+; RUN: opt -S -strip-nonlinetable-debuginfo %s -o - | FileCheck %s
+!llvm.dbg.cu = !{!2, !6}
+!llvm.gcov = !{!3}
+!llvm.module.flags = !{!7}
+
+!1 = !DIFile(filename: "path/to/file", directory: "/path/to/dir")
+; The first CU is used for the line table, the second one is a module skeleton
+; and should be stripped.
+; CHECK: !llvm.dbg.cu = !{![[CU:[0-9]+]]}
+; CHECK: ![[CU]] = distinct !DICompileUnit({{.*}}"abc.debug"{{.*}}LineTablesOnly
+; CHECK-NOT: retainedTypes:
+; CHECK-SAME: )
+; CHECK-NOT: DICompositeType
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang",
+                             isOptimized: true, flags: "-O2", runtimeVersion: 2,
+                             splitDebugFilename: "abc.debug", emissionKind: FullDebug,
+                             retainedTypes: !4)
+!3 = !{!"path/to/file.o", !2}
+!4 = !{!5}
+!5 = !DICompositeType(tag: DW_TAG_structure_type, file: !1, identifier: "ThisWillBeStripped")
+!6 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang",
+                             splitDebugFilename: "abc.dwo", emissionKind: FullDebug,
+                             dwoId: 1234)
+!7 = !{i32 1, !"Debug Info Version", i32 3}

diff --git a/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-localvars.ll b/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-localvars.ll
new file mode 100644 (file)
index 0000000..7ef6b1c
--- /dev/null
+++ b/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-localvars.ll
@@ -0,0 +1,36 @@
+; RUN: opt -S -strip-nonlinetable-debuginfo %s -o - | FileCheck %s
+; CHECK: define void @f() !dbg ![[F:[0-9]+]]
+define void @f() !dbg !4 {
+entry:
+  %i = alloca i32, align 4
+  ; CHECK-NOT: llvm.dbg.declare
+  call void @llvm.dbg.declare(metadata i32* %i, metadata !11, metadata !13), !dbg !14
+  store i32 42, i32* %i, align 4, !dbg !14
+  ret void, !dbg !15
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2)
+!1 = !DIFile(filename: "f.c", directory: "/")
+!2 = !{}
+; CHECK: ![[F]] = distinct !DISubprogram(name: "f"
+; CHECK-NOT: variables:
+; CHECK-NOT: distinct !DISubprogram(name: "f"
+!4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, unit: !0, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = !{i32 2, !"Dwarf Version", i32 2}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"PIC Level", i32 2}
+!10 = !{!"LLVM"}
+!11 = !DILocalVariable(name: "i", scope: !4, file: !1, line: 1, type: !12)
+!12 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!13 = !DIExpression()
+!14 = !DILocation(line: 1, column: 16, scope: !4)
+!15 = !DILocation(line: 1, column: 24, scope: !4)

diff --git a/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-subroutinetypes.ll b/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-subroutinetypes.ll
new file mode 100644 (file)
index 0000000..4245a7b
--- /dev/null
+++ b/llvm/test/Transforms/Util/strip-nonlinetable-debuginfo-subroutinetypes.ll
@@ -0,0 +1,22 @@
+; RUN: opt -S -strip-nonlinetable-debuginfo %s -o - | FileCheck %s
+; Test that subroutine types are downgraded to (void)().
+define internal i32 @"__hidden#2878_"() #0 !dbg !12 {
+  ret i32 0, !dbg !634
+}
+!llvm.dbg.cu = !{!18}
+!llvm.module.flags = !{!482}
+!5 = !{}
+!2 = !{!12}
+; CHECK-NOT: DICompositeType
+; CHECK: distinct !DISubprogram(name: "f", {{.*}}, type: ![[FNTY:[0-9]+]]
+; CHECK: ![[FNTY]] = !DISubroutineType(types: ![[VOID:[0-9]+]])
+; CHECK: ![[VOID]] = !{}
+; CHECK-NOT: DICompositeType
+!12 = distinct !DISubprogram(name: "f", scope: !16, file: !16, line: 133, type: !13, isLocal: true, isDefinition: true, scopeLine: 133, flags: DIFlagPrototyped, isOptimized: true, unit: !18, variables: !5)
+!13 = !DISubroutineType(types: !14)
+!14 = !{!17}
+!16 = !DIFile(filename: "f.m", directory: "/")
+!17 = !DICompositeType(tag: DW_TAG_enumeration_type, name: "e", scope: !18, file: !16, line: 13, size: 32, align: 32, flags: DIFlagFwdDecl)
+!18 = distinct !DICompileUnit(language: DW_LANG_ObjC, file: !16, producer: "clang", isOptimized: true, runtimeVersion: 2, emissionKind: 1, enums: !14, retainedTypes: !14, globals: !5, imports: !5)
+!482 = !{i32 2, !"Debug Info Version", i32 3}
+!634 = !DILocation(line: 143, column: 5, scope: !12)

diff --git a/llvm/tools/bugpoint/CrashDebugger.cpp b/llvm/tools/bugpoint/CrashDebugger.cpp
index a472fff0975e9cb56989c11ea52d9abeac79e19f..0cae0669477f2f5be640ca44cd384c771d9eb516 100644 (file)
--- a/llvm/tools/bugpoint/CrashDebugger.cpp
+++ b/llvm/tools/bugpoint/CrashDebugger.cpp
@@ -19,6 +19,7 @@
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/LegacyPassManager.h"
@@ -54,6 +55,12 @@ cl::opt<bool> DontReducePassList("disable-pass-list-reduction",
 cl::opt<bool> NoNamedMDRM("disable-namedmd-remove",
                           cl::desc("Do not remove global named metadata"),
                           cl::init(false));
+cl::opt<bool> NoStripDebugInfo("disable-strip-debuginfo",
+                               cl::desc("Do not strip debug info metadata"),
+                               cl::init(false));
+cl::opt<bool> NoStripDebugTypeInfo("disable-strip-debug-types",
+                               cl::desc("Do not strip debug type info metadata"),
+                               cl::init(false));
 cl::opt<bool> VerboseErrors("verbose-errors",
                             cl::desc("Print the output of crashing program"),
                             cl::init(false));
@@ -1123,6 +1130,22 @@ static Error DebugACrash(BugDriver &BD,
     if (Error E = ReduceInsts(BD, TestFn))
       return E;
 
+  // Attempt to strip debug info metadata.
+  auto stripMetadata = [&](std::function<bool(Module &)> strip) {
+    std::unique_ptr<Module> M = CloneModule(BD.getProgram());
+    strip(*M);
+    if (TestFn(BD, M.get()))
+      BD.setNewProgram(M.release());
+  };
+  if (!NoStripDebugInfo && !BugpointIsInterrupted) {
+    outs() << "\n*** Attempting to strip the debug info: ";
+    stripMetadata(StripDebugInfo);
+  }
+  if (!NoStripDebugTypeInfo && !BugpointIsInterrupted) {
+    outs() << "\n*** Attempting to strip the debug type info: ";
+    stripMetadata(stripNonLineTableDebugInfo);
+  }
+
   if (!NoNamedMDRM) {
     if (!BugpointIsInterrupted) {
       // Try to reduce the amount of global metadata (particularly debug info),