For the dwarf5 split debug info code split out the string section

per compile unit/skeleton compile unit. Update tests accordingly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171133 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -157,15 +157,18 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
     AbbreviationsSet(InitAbbreviationsSetSize),
     SourceIdMap(DIEValueAllocator), InfoStringPool(DIEValueAllocator),
     PrevLabel(NULL), GlobalCUIndexCount(0),
-    InfoHolder(A, &AbbreviationsSet, &Abbreviations, &InfoStringPool),
+    InfoHolder(A, &AbbreviationsSet, &Abbreviations,
+               &InfoStringPool, "info_string"),
     SkeletonCU(0),
     SkeletonAbbrevSet(InitAbbreviationsSetSize),
-    SkeletonHolder(A, &SkeletonAbbrevSet, &SkeletonAbbrevs, &InfoStringPool) {
+    SkeletonStringPool(DIEValueAllocator),
+    SkeletonHolder(A, &SkeletonAbbrevSet, &SkeletonAbbrevs,
+                   &SkeletonStringPool, "skel_string") {
 
   DwarfInfoSectionSym = DwarfAbbrevSectionSym = 0;
   DwarfStrSectionSym = TextSectionSym = 0;
   DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = 0;
-  DwarfAbbrevDWOSectionSym = 0;
+  DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = 0;
   FunctionBeginSym = FunctionEndSym = 0;
 
   // Turn on accelerator tables and older gdb compatibility
@@ -213,7 +216,7 @@ static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
 }
 
 MCSymbol *DwarfUnits::getStringPoolSym() {
-  return Asm->GetTempSymbol("section_str");
+  return Asm->GetTempSymbol(StringPref);
 }
 
 MCSymbol *DwarfUnits::getStringPoolEntry(StringRef Str) {
@@ -222,7 +225,7 @@ MCSymbol *DwarfUnits::getStringPoolEntry(StringRef Str) {
   if (Entry.first) return Entry.first;
 
   Entry.second = NextStringPoolNumber++;
-  return Entry.first = Asm->GetTempSymbol("string", Entry.second);
+  return Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
 }
 
 // Define a unique number for the abbreviation.
@@ -987,6 +990,8 @@ void DwarfDebug::endModule() {
 
   // Finally emit string information into a string table.
   emitDebugStr();
+  if (useSplitDwarf())
+    emitDebugStrDWO();
 
   // clean up.
   SPMap.clear();
@@ -1724,7 +1729,10 @@ void DwarfDebug::emitSectionLabels() {
   emitSectionSym(Asm, TLOF.getDwarfLocSection());
   emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
   DwarfStrSectionSym =
-    emitSectionSym(Asm, TLOF.getDwarfStrSection(), "section_str");
+    emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
+  if (useSplitDwarf())
+    DwarfStrDWOSectionSym =
+      emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
   DwarfDebugRangeSectionSym = emitSectionSym(Asm, TLOF.getDwarfRangesSection(),
                                              "debug_range");
 
@@ -2107,23 +2115,21 @@ void DwarfDebug::emitDebugPubTypes() {
   }
 }
 
-// Emit visible names into a debug str section.
+// Emit strings into a string section.
-void DwarfDebug::emitDebugStr() {
+void DwarfUnits::emitStrings(const MCSection *Section) {
-  // Check to see if it is worth the effort.
+
-  if (InfoHolder.getStringPool()->empty()) return;
+  if (StringPool->empty()) return;
 
   // Start the dwarf str section.
-  Asm->OutStreamer.SwitchSection(
+  Asm->OutStreamer.SwitchSection(Section);
-                                Asm->getObjFileLowering().getDwarfStrSection());
 
   // Get all of the string pool entries and put them in an array by their ID so
   // we can sort them.
   SmallVector<std::pair<unsigned,
-      StringMapEntry<std::pair<MCSymbol*, unsigned> >*>, 64> Entries;
+                        StringMapEntry<std::pair<MCSymbol*, unsigned> >*>, 64> Entries;
 
   for (StringMap<std::pair<MCSymbol*, unsigned> >::iterator
-       I = InfoHolder.getStringPool()->begin(),
+         I = StringPool->begin(), E = StringPool->end();
-         E = InfoHolder.getStringPool()->end();
        I != E; ++I)
     Entries.push_back(std::make_pair(I->second.second, &*I));
 
@@ -2140,6 +2146,12 @@ void DwarfDebug::emitDebugStr() {
   }
 }
 
+// Emit visible names into a debug str section.
+void DwarfDebug::emitDebugStr() {
+  DwarfUnits &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
+  Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
+}
+
 // Emit visible names into a debug loc section.
 void DwarfDebug::emitDebugLoc() {
   if (DotDebugLocEntries.empty())
@@ -2363,7 +2375,7 @@ CompileUnit *DwarfDebug::constructSkeletonCU(const MDNode *N) {
   DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
   CompileUnit *NewCU = new CompileUnit(GlobalCUIndexCount++,
                                        DIUnit.getLanguage(), Die, Asm,
-                                       this, &InfoHolder);
+                                       this, &SkeletonHolder);
   // FIXME: This should be the .dwo file.
   NewCU->addString(Die, dwarf::DW_AT_GNU_dwo_name, FN);
 
@@ -2440,3 +2452,11 @@ void DwarfDebug::emitDebugAbbrevDWO() {
   emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection(),
               &Abbreviations);
 }
+
+// Emit the .debug_str.dwo section for separated dwarf. This contains the
+// string section and is identical in format to traditional .debug_str
+// sections.
+void DwarfDebug::emitDebugStrDWO() {
+  assert(useSplitDwarf() && "No split dwarf?");
+  InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection());
+}

lib/CodeGen/AsmPrinter/DwarfDebug.h

@@ -210,15 +210,17 @@ class DwarfUnits {
   // A pointer to all units in the section.
   SmallVector<CompileUnit *, 1> CUs;
 
-  // Collection of strings for this unit.
+  // Collection of strings for this unit and assorted symbols.
   StrPool *StringPool;
   unsigned NextStringPoolNumber;
+  std::string StringPref;
 
 public:
   DwarfUnits(AsmPrinter *AP, FoldingSet<DIEAbbrev> *AS,
-             std::vector<DIEAbbrev *> *A, StrPool *SP) :
+             std::vector<DIEAbbrev *> *A,
+             StrPool *SP, const char *Pref) :
     Asm(AP), AbbreviationsSet(AS), Abbreviations(A),
-    StringPool(SP), NextStringPoolNumber(0) {}
+    StringPool(SP), NextStringPoolNumber(0), StringPref(Pref) {}
 
   /// \brief Compute the size and offset of a DIE given an incoming Offset.
   unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
@@ -237,6 +239,9 @@ public:
   void emitUnits(DwarfDebug *, const MCSection *, const MCSection *,
                  const MCSymbol *);
 
+  /// \brief Emit all of the strings to the section given.
+  void emitStrings(const MCSection *);
+
   /// \brief Returns the entry into the start of the pool.
   MCSymbol *getStringPoolSym();
 
@@ -364,7 +369,7 @@ class DwarfDebug {
   MCSymbol *DwarfStrSectionSym, *TextSectionSym, *DwarfDebugRangeSectionSym;
   MCSymbol *DwarfDebugLocSectionSym;
   MCSymbol *FunctionBeginSym, *FunctionEndSym;
-  MCSymbol *DwarfAbbrevDWOSectionSym;
+  MCSymbol *DwarfAbbrevDWOSectionSym, *DwarfStrDWOSectionSym;
 
   // As an optimization, there is no need to emit an entry in the directory
   // table for the same directory as DW_at_comp_dir.
@@ -394,12 +399,16 @@ class DwarfDebug {
   // The CU left in the original object file for separated debug info.
   CompileUnit *SkeletonCU;
 
-    // Used to uniquely define abbreviations for the skeleton emission.
+  // Used to uniquely define abbreviations for the skeleton emission.
   FoldingSet<DIEAbbrev> SkeletonAbbrevSet;
 
   // A list of all the unique abbreviations in use.
   std::vector<DIEAbbrev *> SkeletonAbbrevs;
 
+  // List of strings used in the skeleton.
+  StrPool SkeletonStringPool;
+
+  // Holder for the skeleton information.
   DwarfUnits SkeletonHolder;
 
 private:
@@ -514,6 +523,9 @@ private:
   /// \brief Emit the debug abbrev dwo section.
   void emitDebugAbbrevDWO();
 
+  /// \brief Emit the debug str dwo section.
+  void emitDebugStrDWO();
+
   /// \brief Create new CompileUnit for the given metadata node with tag
   /// DW_TAG_compile_unit.
   CompileUnit *constructCompileUnit(const MDNode *N);

test/DebugInfo/X86/fission-cu.ll

@@ -20,10 +20,10 @@
 ; DW_AT_ranges_base, DW_AT_addr_base.
 
 ; CHECK: DW_TAG_compile_unit
-; CHECK: DW_AT_GNU_dwo_name [DW_FORM_strp] ( .debug_str[0x00000035] = "baz.c")
+; CHECK: DW_AT_GNU_dwo_name [DW_FORM_strp] ( .debug_str[0x00000000] = "baz.c")
 ; CHECK: DW_AT_low_pc [DW_FORM_addr]       (0x0000000000000000)
 ; CHECK: DW_AT_stmt_list [DW_FORM_data4]   (0x00000000)
-; CHECK: DW_AT_comp_dir [DW_FORM_strp]     ( .debug_str[0x0000003b] = "/usr/local/google/home/echristo/tmp")
+; CHECK: DW_AT_comp_dir [DW_FORM_strp]     ( .debug_str[0x00000006] = "/usr/local/google/home/echristo/tmp")
 
 ; Make sure there's only one compile unit for now.
 ; CHECK-NOT: DW_TAG_compile_unit

test/DebugInfo/X86/stringpool.ll

@@ -15,7 +15,7 @@
 !7 = metadata !{i32 720932, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
 
 ; Verify that we refer to 'yyyy' with a relocation.
-; LINUX:      .long   .Lstring3               # DW_AT_name
+; LINUX:      .long   .Linfo_string3          # DW_AT_name
 ; LINUX-NEXT: .long   38                      # DW_AT_type
 ; LINUX-NEXT:                                 # DW_AT_external
 ; LINUX-NEXT: .byte   1                       # DW_AT_decl_file
@@ -25,7 +25,7 @@
 ; LINUX-NEXT: .quad   yyyy
 
 ; Verify that we refer to 'yyyy' without a relocation.
-; DARWIN: Lset5 = Lstring3-Lsection_str               ## DW_AT_name
+; DARWIN: Lset5 = Linfo_string3-Linfo_string          ## DW_AT_name
 ; DARWIN-NEXT:        .long   Lset5
 ; DARWIN-NEXT:        .long   39                      ## DW_AT_type
 ; DARWIN-NEXT:        .byte   1                       ## DW_AT_external