Refactor out the abbreviation handling into a separate class that

controls each of the abbreviation sets (only a single one at the
moment) and computes offsets separately as well for each set
of DIEs.

No real function change, ordering of abbreviations for the skeleton
CU changed but only because we're computing in a separate order. Fix
the testcase not to care.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169793 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -156,7 +156,9 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
   : Asm(A), MMI(Asm->MMI), FirstCU(0),
     AbbreviationsSet(InitAbbreviationsSetSize),
     SourceIdMap(DIEValueAllocator), StringPool(DIEValueAllocator),
-    PrevLabel(NULL), GlobalCUIndexCount(0), SkeletonCU(0) {
+    PrevLabel(NULL), GlobalCUIndexCount(0),
+    InfoHolder(A, &AbbreviationsSet, &Abbreviations),
+    SkeletonCU(0), SkeletonHolder(A, &AbbreviationsSet, &Abbreviations) {
   NextStringPoolNumber = 0;
 
   DwarfInfoSectionSym = DwarfAbbrevSectionSym = 0;
@@ -222,21 +224,21 @@ MCSymbol *DwarfDebug::getStringPoolEntry(StringRef Str) {
 
 // Define a unique number for the abbreviation.
 //
-void DwarfDebug::assignAbbrevNumber(DIEAbbrev &Abbrev) {
+void DwarfUnits::assignAbbrevNumber(DIEAbbrev &Abbrev) {
   // Profile the node so that we can make it unique.
   FoldingSetNodeID ID;
   Abbrev.Profile(ID);
 
   // Check the set for priors.
-  DIEAbbrev *InSet = AbbreviationsSet.GetOrInsertNode(&Abbrev);
+  DIEAbbrev *InSet = AbbreviationsSet->GetOrInsertNode(&Abbrev);
 
   // If it's newly added.
   if (InSet == &Abbrev) {
     // Add to abbreviation list.
-    Abbreviations.push_back(&Abbrev);
+    Abbreviations->push_back(&Abbrev);
 
     // Assign the vector position + 1 as its number.
-    Abbrev.setNumber(Abbreviations.size());
+    Abbrev.setNumber(Abbreviations->size());
   } else {
     // Assign existing abbreviation number.
     Abbrev.setNumber(InSet->getNumber());
@@ -655,6 +657,8 @@ CompileUnit *DwarfDebug::constructCompileUnit(const MDNode *N) {
   if (useSplitDwarf() && !SkeletonCU)
     SkeletonCU = constructSkeletonCU(N);
 
+  InfoHolder.addUnit(NewCU);
+
   CUMap.insert(std::make_pair(N, NewCU));
   return NewCU;
 }
@@ -871,7 +875,9 @@ void DwarfDebug::finalizeModuleInfo() {
   }
 
    // Compute DIE offsets and sizes.
-  computeSizeAndOffsets();
+  InfoHolder.computeSizeAndOffsets();
+  if (useSplitDwarf())
+    SkeletonHolder.computeSizeAndOffsets();
 }
 
 void DwarfDebug::endSections() {
@@ -1635,7 +1641,7 @@ void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
 
 // Compute the size and offset of a DIE.
 unsigned
-DwarfDebug::computeSizeAndOffset(DIE *Die, unsigned Offset) {
+DwarfUnits::computeSizeAndOffset(DIE *Die, unsigned Offset) {
   // Get the children.
   const std::vector<DIE *> &Children = Die->getChildren();
 
@@ -1644,7 +1650,7 @@ DwarfDebug::computeSizeAndOffset(DIE *Die, unsigned Offset) {
 
   // Get the abbreviation for this DIE.
   unsigned AbbrevNumber = Die->getAbbrevNumber();
-  const DIEAbbrev *Abbrev = Abbreviations[AbbrevNumber - 1];
+  const DIEAbbrev *Abbrev = Abbreviations->at(AbbrevNumber - 1);
 
   // Set DIE offset
   Die->setOffset(Offset);
@@ -1677,25 +1683,16 @@ DwarfDebug::computeSizeAndOffset(DIE *Die, unsigned Offset) {
 }
 
 // Compute the size and offset of all the DIEs.
-void DwarfDebug::computeSizeAndOffsets() {
+void DwarfUnits::computeSizeAndOffsets() {
-  if (SkeletonCU) {
+  for (SmallVector<CompileUnit *, 1>::iterator I = CUs.begin(),
+         E = CUs.end(); I != E; ++I) {
     unsigned Offset =
       sizeof(int32_t) + // Length of Compilation Unit Info
       sizeof(int16_t) + // DWARF version number
       sizeof(int32_t) + // Offset Into Abbrev. Section
       sizeof(int8_t);   // Pointer Size (in bytes)
 
-    computeSizeAndOffset(SkeletonCU->getCUDie(), Offset);
+    computeSizeAndOffset((*I)->getCUDie(), Offset);
-  }
-  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
-         E = CUMap.end(); I != E; ++I) {
-    // Compute size of compile unit header.
-    unsigned Offset =
-      sizeof(int32_t) + // Length of Compilation Unit Info
-      sizeof(int16_t) + // DWARF version number
-      sizeof(int32_t) + // Offset Into Abbrev. Section
-      sizeof(int8_t);   // Pointer Size (in bytes)
-    computeSizeAndOffset(I->second->getCUDie(), Offset);
   }
 }
 
@@ -2351,6 +2348,8 @@ CompileUnit *DwarfDebug::constructSkeletonCU(const MDNode *N) {
   if (!CompilationDir.empty())
     NewCU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
 
+  SkeletonHolder.addUnit(NewCU);
+
   return NewCU;
 }
 

lib/CodeGen/AsmPrinter/DwarfDebug.h

@@ -188,6 +188,39 @@ public:
   DIType getType() const;
 };
 
+/// \brief Collects and handles information specific to a particular
+/// collection of units.
+class DwarfUnits {
+  // Target of Dwarf emission, used for sizing of abbreviations.
+  AsmPrinter *Asm;
+
+  // 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<CompileUnit *, 1> CUs;
+
+public:
+  DwarfUnits(AsmPrinter *AP, FoldingSet<DIEAbbrev> *AS,
+             std::vector<DIEAbbrev *> *A) :
+    Asm(AP), AbbreviationsSet(AS), Abbreviations(A) {}
+
+  /// \brief Compute the size and offset of a DIE given an incoming Offset.
+  unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
+
+  /// \brief Compute the size and offset of all the DIEs.
+  void computeSizeAndOffsets();
+
+  /// \brief Define a unique number for the abbreviation.
+  void assignAbbrevNumber(DIEAbbrev &Abbrev);
+
+  /// \brief Add a unit to the list of CUs.
+  void addUnit(CompileUnit *CU) { CUs.push_back(CU); }
+};
+
 /// \brief Collects and handles dwarf debug information.
 class DwarfDebug {
   // Target of Dwarf emission.
@@ -312,6 +345,9 @@ class DwarfDebug {
   // Counter for assigning globally unique IDs for CUs.
   unsigned GlobalCUIndexCount;
 
+  // Holder for the file specific debug information.
+  DwarfUnits InfoHolder;
+
   // Holders for the various debug information flags that we might need to
   // have exposed. See accessor functions below for description.
 
@@ -329,12 +365,10 @@ class DwarfDebug {
 
   // The CU left in the original object file for Fission debug info.
   CompileUnit *SkeletonCU;
+  DwarfUnits SkeletonHolder;
 
 private:
 
-  /// \brief Define a unique number for the abbreviation.
-  void assignAbbrevNumber(DIEAbbrev &Abbrev);
-
   void addScopeVariable(LexicalScope *LS, DbgVariable *Var);
 
   /// \brief Find abstract variable associated with Var.

test/DebugInfo/X86/fission-cu.ll

@@ -19,7 +19,7 @@
 ; DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
 ; DW_AT_ranges_base, DW_AT_addr_base.
 
-; CHECK: DW_TAG_compile_unit [1]  
+; CHECK: DW_TAG_compile_unit
 ; CHECK: DW_AT_GNU_dwo_name [DW_FORM_strp] ( .debug_str[0x00000035] = "baz.c")
 ; CHECK: DW_AT_low_pc [DW_FORM_addr]       (0x0000000000000000)
 ; CHECK: DW_AT_stmt_list [DW_FORM_data4]   (0x00000000)