Move emitDIE and emitAbbrev to AsmPrinter. NFC.

[friss]

Summary

I would have commited taht as obvious, but I thought I'd check with you
if it doesn't break some layering between the AsmPrinter and the various
Dwarf* classes.

llvm-dsymutil wants to reuse that code, but it doesn't have a DwarfUnit or
a DwarfDebug object to call those. It has access to an AsmPrinter though.

Having emitDIE in the AsmPrinter also removes the DwarfFile dependency
on DwarfDebug, and thus the patch drops that field.

Note the the patch won't compile as such, it needs a preliminary pass of
const-correctness fix to DIE.{h,cpp}.

[echristo]

Looks good in theory.

I'd probably rename the emitDIE and emitAbbrevs to be emitDwarfDIE etc as part of the migration.

-eric

include/llvm/CodeGen/AsmPrinter.h

 
 namespace llvm {
 class AsmPrinterHandler;
 class BlockAddress;
 class ByteStreamer;
 class GCStrategy;
 class Constant;
 class ConstantArray;
+class DIE;
+class DIEAbbrev;
 class GCMetadataPrinter;
 class GlobalValue;
 class GlobalVariable;
 class MachineBasicBlock;
 class MachineFunction;
 class MachineInstr;
 class MachineLocation;
 class MachineLoopInfo;
public:
 
   //===------------------------------------------------------------------===//
   // Dwarf Lowering Routines
   //===------------------------------------------------------------------===//
 
   /// \brief Emit frame instruction to describe the layout of the frame.
   void emitCFIInstruction(const MCCFIInstruction &Inst) const;
 
+  /// \brief Emit abbreviation table.
+  void emitAbbrevs(const std::vector<DIEAbbrev *>& Abbrevs) const;
+
+  /// \brief Recursively emit DIE tree.
+  void emitDIE(const DIE &Die) const;
+
   //===------------------------------------------------------------------===//
   // Inline Asm Support
   //===------------------------------------------------------------------===//
 public:
   // These are hooks that targets can override to implement inline asm
   // support.  These should probably be moved out of AsmPrinter someday.
 
   /// Print information related to the specified machine instr that is

lib/CodeGen/AsmPrinter/AsmPrinter.cpp

 #include "DwarfException.h"
 #include "Win64Exception.h"
 #include "WinCodeViewLineTables.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/JumpInstrTableInfo.h"
 #include "llvm/CodeGen/Analysis.h"
+#include "llvm/CodeGen/DIE.h"
 #include "llvm/CodeGen/GCMetadataPrinter.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBundle.h"
 #include "llvm/CodeGen/MachineJumpTableInfo.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
 
   const MachineModuleInfo &MMI = MF->getMMI();
   const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
   unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
   const MCCFIInstruction &CFI = Instrs[CFIIndex];
   emitCFIInstruction(CFI);
 }
 
+void AsmPrinter::emitDIE(const DIE &Die) const {
+  // Get the abbreviation for this DIE.
+  const DIEAbbrev &Abbrev = Die.getAbbrev();
+
+  // Emit the code (index) for the abbreviation.
+  if (isVerbose())
+    OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
+                           "] 0x" + Twine::utohexstr(Die.getOffset()) +
+                           ":0x" + Twine::utohexstr(Die.getSize()) + " " +
+                           dwarf::TagString(Abbrev.getTag()));
+  EmitULEB128(Abbrev.getNumber());
+
+  const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
+  const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
+
+  // Emit the DIE attribute values.
+  for (unsigned i = 0, N = Values.size(); i < N; ++i) {
+    dwarf::Attribute Attr = AbbrevData[i].getAttribute();
+    dwarf::Form Form = AbbrevData[i].getForm();
+    assert(Form && "Too many attributes for DIE (check abbreviation)");
+
+    if (isVerbose()) {
+      OutStreamer.AddComment(dwarf::AttributeString(Attr));
+      if (Attr == dwarf::DW_AT_accessibility)
+        OutStreamer.AddComment(dwarf::AccessibilityString(
+            cast<DIEInteger>(Values[i])->getValue()));
+    }
+
+    // Emit an attribute using the defined form.
+    Values[i]->EmitValue(this, Form);
+  }
+
+  // Emit the DIE children if any.
+  if (Abbrev.hasChildren()) {
+    for (auto &Child : Die.getChildren())
+      emitDIE(*Child);
+
+    OutStreamer.AddComment("End Of Children Mark");
+    EmitInt8(0);
+  }
+}
+
+void AsmPrinter::emitAbbrevs(const std::vector<DIEAbbrev *>& Abbrevs) const {
+  // For each abbrevation.
+  for (const DIEAbbrev *Abbrev : Abbrevs) {
+    // Emit the abbrevations code (base 1 index.)
+    EmitULEB128(Abbrev->getNumber(), "Abbreviation Code");
+
+    // Emit the abbreviations data.
+    Abbrev->Emit(this);
+  }
+
+  // Mark end of abbreviations.
+  EmitULEB128(0, "EOM(3)");
+}
+
 void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
   // The operands are the MCSymbol and the frame offset of the allocation.
   MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
   int FrameOffset = MI.getOperand(1).getImm();
 
   // Emit a symbol assignment.
   OutStreamer.EmitAssignment(FrameAllocSym,
                              MCConstantExpr::Create(FrameOffset, OutContext));

lib/CodeGen/AsmPrinter/DwarfDebug.h

public:
   void addArangeLabel(SymbolCU SCU) { ArangeLabels.push_back(SCU); }
 
   /// \brief For symbols that have a size designated (e.g. common symbols),
   /// this tracks that size.
   void setSymbolSize(const MCSymbol *Sym, uint64_t Size) override {
     SymSize[Sym] = Size;
   }
 
-  /// \brief Recursively Emits a debug information entry.
-  void emitDIE(DIE &Die);
-
   // Experimental DWARF5 features.
 
   /// \brief Returns whether or not to emit tables that dwarf consumers can
   /// use to accelerate lookup.
   bool useDwarfAccelTables() const { return HasDwarfAccelTables; }
 
   /// \brief Returns whether or not to change the current debug info for the
   /// split dwarf proposal support.

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

 
 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
     DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
     DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
     DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
 
 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
     : Asm(A), MMI(Asm->MMI), PrevLabel(nullptr), GlobalRangeCount(0),
-      InfoHolder(A, *this, "info_string", DIEValueAllocator),
+      InfoHolder(A, "info_string", DIEValueAllocator),
       UsedNonDefaultText(false),
-      SkeletonHolder(A, *this, "skel_string", DIEValueAllocator),
+      SkeletonHolder(A, "skel_string", DIEValueAllocator),
       IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
       AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
                                        dwarf::DW_FORM_data4)),
       AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
                                       dwarf::DW_FORM_data4)),
       AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
                                            dwarf::DW_FORM_data4)),
       AccelTypes(TypeAtoms) {
DwarfDebugLocSectionSym =
         emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
   } else
     DwarfDebugLocSectionSym =
         emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
   DwarfDebugRangeSectionSym =
       emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
 }
 
-// Recursively emits a debug information entry.
-void DwarfDebug::emitDIE(DIE &Die) {
-  // Get the abbreviation for this DIE.
-  const DIEAbbrev &Abbrev = Die.getAbbrev();
-
-  // Emit the code (index) for the abbreviation.
-  if (Asm->isVerbose())
-    Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
-                                "] 0x" + Twine::utohexstr(Die.getOffset()) +
-                                ":0x" + Twine::utohexstr(Die.getSize()) + " " +
-                                dwarf::TagString(Abbrev.getTag()));
-  Asm->EmitULEB128(Abbrev.getNumber());
-
-  const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
-  const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
-
-  // Emit the DIE attribute values.
-  for (unsigned i = 0, N = Values.size(); i < N; ++i) {
-    dwarf::Attribute Attr = AbbrevData[i].getAttribute();
-    dwarf::Form Form = AbbrevData[i].getForm();
-    assert(Form && "Too many attributes for DIE (check abbreviation)");
-
-    if (Asm->isVerbose()) {
-      Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
-      if (Attr == dwarf::DW_AT_accessibility)
-        Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
-            cast<DIEInteger>(Values[i])->getValue()));
-    }
-
-    // Emit an attribute using the defined form.
-    Values[i]->EmitValue(Asm, Form);
-  }
-
-  // Emit the DIE children if any.
-  if (Abbrev.hasChildren()) {
-    for (auto &Child : Die.getChildren())
-      emitDIE(*Child);
-
-    Asm->OutStreamer.AddComment("End Of Children Mark");
-    Asm->EmitInt8(0);
-  }
-}
-
 // Emit the debug info section.
 void DwarfDebug::emitDebugInfo() {
   DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
 
   Holder.emitUnits(DwarfAbbrevSectionSym);
 }
 
 // Emit the abbreviation section.

lib/CodeGen/AsmPrinter/DwarfFile.h

 class LexicalScope;
 class StringRef;
 class DwarfDebug;
 class MCSection;
 class DwarfFile {
   // Target of Dwarf emission, used for sizing of abbreviations.
   AsmPrinter *Asm;
 
-  DwarfDebug ⅅ
-
   // Used to uniquely define abbreviations.
   FoldingSet<DIEAbbrev> AbbreviationsSet;
 
   // A list of all the unique abbreviations in use.
   std::vector<DIEAbbrev *> Abbreviations;
 
   // A pointer to all units in the section.
   SmallVector<std::unique_ptr<DwarfUnit>, 1> CUs;
 
   DwarfStringPool StrPool;
 
   // Collection of dbg variables of a scope.
   DenseMap<LexicalScope *, SmallVector<DbgVariable *, 8>> ScopeVariables;
 
   // Collection of abstract subprogram DIEs.
   DenseMap<const MDNode *, DIE *> AbstractSPDies;
 
   /// Maps MDNodes for type system with the corresponding DIEs. These DIEs can
   /// be shared across CUs, that is why we keep the map here instead
   /// of in DwarfCompileUnit.
   DenseMap<const MDNode *, DIE *> MDTypeNodeToDieMap;
 
 public:
-  DwarfFile(AsmPrinter *AP, DwarfDebug &DD, StringRef Pref,
-            BumpPtrAllocator &DA);
+  DwarfFile(AsmPrinter *AP, StringRef Pref, BumpPtrAllocator &DA);
 
   ~DwarfFile();
 
   const SmallVectorImpl<std::unique_ptr<DwarfUnit>> &getUnits() { return CUs; }
 
   /// \brief Compute the size and offset of a DIE given an incoming Offset.
   unsigned computeSizeAndOffset(DIE &Die, unsigned Offset);
 

lib/CodeGen/AsmPrinter/DwarfFile.cpp

 #include "DwarfUnit.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/Support/LEB128.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
 
 namespace llvm {
-DwarfFile::DwarfFile(AsmPrinter *AP, DwarfDebug &DD, StringRef Pref,
-                     BumpPtrAllocator &DA)
-    : Asm(AP), DD(DD), StrPool(DA, *Asm, Pref) {}
+DwarfFile::DwarfFile(AsmPrinter *AP, StringRef Pref, BumpPtrAllocator &DA)
+    : Asm(AP), StrPool(DA, *Asm, Pref) {}
 
 DwarfFile::~DwarfFile() {}
 
 // Define a unique number for the abbreviation.
 //
 void DwarfFile::assignAbbrevNumber(DIEAbbrev &Abbrev) {
   // Check the set for priors.
   DIEAbbrev *InSet = AbbreviationsSet.GetOrInsertNode(&Abbrev);

 void DwarfFile::emitUnits(const MCSymbol *ASectionSym) {
   for (const auto &TheU : CUs) {
     DIE &Die = TheU->getUnitDie();
     const MCSection *USection = TheU->getSection();
     Asm->OutStreamer.SwitchSection(USection);
 
     TheU->emitHeader(ASectionSym);
 
-    DD.emitDIE(Die);
+    Asm->emitDIE(Die);
   }
 }
 
 // Compute the size and offset for each DIE.
 void DwarfFile::computeSizeAndOffsets() {
   // Offset from the first CU in the debug info section is 0 initially.
   unsigned SecOffset = 0;
 
unsigned DwarfFile::computeSizeAndOffset(DIE &Die, unsigned Offset) {
   Die.setSize(Offset - Die.getOffset());
   return Offset;
 }
 void DwarfFile::emitAbbrevs(const MCSection *Section) {
   // Check to see if it is worth the effort.
   if (!Abbreviations.empty()) {
     // Start the debug abbrev section.
     Asm->OutStreamer.SwitchSection(Section);
-
-    // For each abbrevation.
-    for (const DIEAbbrev *Abbrev : Abbreviations) {
-      // Emit the abbrevations code (base 1 index.)
-      Asm->EmitULEB128(Abbrev->getNumber(), "Abbreviation Code");
-
-      // Emit the abbreviations data.
-      Abbrev->Emit(Asm);
-    }
-
-    // Mark end of abbreviations.
-    Asm->EmitULEB128(0, "EOM(3)");
+    Asm->emitAbbrevs(Abbreviations);
   }
 }
 
 // Emit strings into a string section.
 void DwarfFile::emitStrings(const MCSection *StrSection,
                             const MCSection *OffsetSection) {
   StrPool.emit(*Asm, StrSection, OffsetSection);
 }