DebugInfo: Wrap section data and relocs together for dwarf dumping support

This is a small step that may enable some simplifications in producer
(DWARFContext) and consumer (DWARFCompileUnit and other places) by
making a more complete abstraction around the data and relocations for a
section. Small initial steps could include simple changes such as
passing the pair to DWARFCompileUnit's ctor rather than passing the data
and relocs separately. I don't intend to pursue any such changes
immediately, however.

The motivation for doing this now is that type unit dumping will need to
deal with these data+reloc pairs moreso than the existing dumping
support has needed to associate the data as type unit sections are named
the same (debug_types) and comdat group folded. So to implement dumping
and reloc handling we'll need a mapping of section->data+relocs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191209 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 39 insertions, 48 deletions

diff --git a/lib/DebugInfo/DWARFContext.cpp b/lib/DebugInfo/DWARFContext.cpp
index 380f75f..075d8cd 100644
--- a/lib/DebugInfo/DWARFContext.cpp
+++ b/lib/DebugInfo/DWARFContext.cpp
@@ -69,10 +69,10 @@ void DWARFContext::dump(raw_ostream &OS, DIDumpType DumpType) {
         cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
                                                              -1U);
       if (stmtOffset != -1U) {
-        DataExtractor lineData(getLineSection(), isLittleEndian(),
+        DataExtractor lineData(getLineSection().Data, isLittleEndian(),
                                savedAddressByteSize);
         DWARFDebugLine::DumpingState state(OS);
-        DWARFDebugLine::parseStatementTable(lineData, &lineRelocMap(), &stmtOffset, state);
+        DWARFDebugLine::parseStatementTable(lineData, &getLineSection().Relocs, &stmtOffset, state);
       }
     }
   }
@@ -206,8 +206,8 @@ const DWARFDebugLoc *DWARFContext::getDebugLoc() {
   if (Loc)
     return Loc.get();
 
-  DataExtractor LocData(getLocSection(), isLittleEndian(), 0);
-  Loc.reset(new DWARFDebugLoc(locRelocMap()));
+  DataExtractor LocData(getLocSection().Data, isLittleEndian(), 0);
+  Loc.reset(new DWARFDebugLoc(getLocSection().Relocs));
   // assume all compile units have the same address byte size
   if (getNumCompileUnits())
     Loc->parse(LocData, getCompileUnitAtIndex(0)->getAddressByteSize());
@@ -252,7 +252,7 @@ const DWARFDebugFrame *DWARFContext::getDebugFrame() {
 const DWARFLineTable *
 DWARFContext::getLineTableForCompileUnit(DWARFCompileUnit *cu) {
   if (!Line)
-    Line.reset(new DWARFDebugLine(&lineRelocMap()));
+    Line.reset(new DWARFDebugLine(&getLineSection().Relocs));
 
   unsigned stmtOffset =
     cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
@@ -265,20 +265,20 @@ DWARFContext::getLineTableForCompileUnit(DWARFCompileUnit *cu) {
     return lt;
 
   // We have to parse it first.
-  DataExtractor lineData(getLineSection(), isLittleEndian(),
+  DataExtractor lineData(getLineSection().Data, isLittleEndian(),
                          cu->getAddressByteSize());
   return Line->getOrParseLineTable(lineData, stmtOffset);
 }
 
 void DWARFContext::parseCompileUnits() {
   uint32_t offset = 0;
-  const DataExtractor &DIData = DataExtractor(getInfoSection(),
+  const DataExtractor &DIData = DataExtractor(getInfoSection().Data,
                                               isLittleEndian(), 0);
   while (DIData.isValidOffset(offset)) {
     OwningPtr<DWARFCompileUnit> CU(new DWARFCompileUnit(
-        getDebugAbbrev(), getInfoSection(), getAbbrevSection(),
+        getDebugAbbrev(), getInfoSection().Data, getAbbrevSection(),
         getRangeSection(), getStringSection(), StringRef(), getAddrSection(),
-        &infoRelocMap(), isLittleEndian()));
+        &getInfoSection().Relocs, isLittleEndian()));
     if (!CU->extract(DIData, &offset)) {
       break;
     }
@@ -289,14 +289,14 @@ void DWARFContext::parseCompileUnits() {
 
 void DWARFContext::parseDWOCompileUnits() {
   uint32_t offset = 0;
-  const DataExtractor &DIData = DataExtractor(getInfoDWOSection(),
-                                              isLittleEndian(), 0);
+  const DataExtractor &DIData =
+      DataExtractor(getInfoDWOSection().Data, isLittleEndian(), 0);
   while (DIData.isValidOffset(offset)) {
     OwningPtr<DWARFCompileUnit> DWOCU(new DWARFCompileUnit(
-        getDebugAbbrevDWO(), getInfoDWOSection(), getAbbrevDWOSection(),
+        getDebugAbbrevDWO(), getInfoDWOSection().Data, getAbbrevDWOSection(),
         getRangeDWOSection(), getStringDWOSection(),
-        getStringOffsetDWOSection(), getAddrSection(), &infoDWORelocMap(),
-        isLittleEndian()));
+        getStringOffsetDWOSection(), getAddrSection(),
+        &getInfoDWOSection().Relocs, isLittleEndian()));
     if (!DWOCU->extract(DIData, &offset)) {
       break;
     }
@@ -574,17 +574,17 @@ DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
     }
 
     StringRef *Section = StringSwitch<StringRef*>(name)
-        .Case("debug_info", &InfoSection)
+        .Case("debug_info", &InfoSection.Data)
         .Case("debug_abbrev", &AbbrevSection)
-        .Case("debug_loc", &LocSection)
-        .Case("debug_line", &LineSection)
+        .Case("debug_loc", &LocSection.Data)
+        .Case("debug_line", &LineSection.Data)
         .Case("debug_aranges", &ARangeSection)
         .Case("debug_frame", &DebugFrameSection)
         .Case("debug_str", &StringSection)
         .Case("debug_ranges", &RangeSection)
         .Case("debug_pubnames", &PubNamesSection)
         .Case("debug_gnu_pubnames", &GnuPubNamesSection)
-        .Case("debug_info.dwo", &InfoDWOSection)
+        .Case("debug_info.dwo", &InfoDWOSection.Data)
         .Case("debug_abbrev.dwo", &AbbrevDWOSection)
         .Case("debug_str.dwo", &StringDWOSection)
         .Case("debug_str_offsets.dwo", &StringOffsetDWOSection)
@@ -611,10 +611,10 @@ DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
     // TODO: Add support for relocations in other sections as needed.
     // Record relocations for the debug_info and debug_line sections.
     RelocAddrMap *Map = StringSwitch<RelocAddrMap*>(RelSecName)
-        .Case("debug_info", &InfoRelocMap)
-        .Case("debug_loc", &LocRelocMap)
-        .Case("debug_info.dwo", &InfoDWORelocMap)
-        .Case("debug_line", &LineRelocMap)
+        .Case("debug_info", &InfoSection.Relocs)
+        .Case("debug_loc", &LocSection.Relocs)
+        .Case("debug_info.dwo", &InfoDWOSection.Relocs)
+        .Case("debug_line", &LineSection.Relocs)
         .Default(0);
     if (!Map)
       continue;
diff --git a/lib/DebugInfo/DWARFContext.h b/lib/DebugInfo/DWARFContext.h
index e4b640e4c..cda4475 100644
--- a/lib/DebugInfo/DWARFContext.h
+++ b/lib/DebugInfo/DWARFContext.h
@@ -48,6 +48,11 @@ class DWARFContext : public DIContext {
   void parseDWOCompileUnits();
 
 public:
+  struct Section {
+    StringRef Data;
+    RelocAddrMap Relocs;
+  };
+
   DWARFContext() : DIContext(CK_DWARF) {}
   virtual ~DWARFContext();
 
@@ -113,28 +118,24 @@ public:
 
   virtual bool isLittleEndian() const = 0;
   virtual uint8_t getAddressSize() const = 0;
-  virtual const RelocAddrMap &infoRelocMap() const = 0;
-  virtual const RelocAddrMap &lineRelocMap() const = 0;
-  virtual const RelocAddrMap &locRelocMap() const = 0;
-  virtual StringRef getInfoSection() = 0;
+  virtual const Section &getInfoSection() = 0;
   virtual StringRef getAbbrevSection() = 0;
-  virtual StringRef getLocSection() = 0;
+  virtual const Section &getLocSection() = 0;
   virtual StringRef getARangeSection() = 0;
   virtual StringRef getDebugFrameSection() = 0;
-  virtual StringRef getLineSection() = 0;
+  virtual const Section &getLineSection() = 0;
   virtual StringRef getStringSection() = 0;
   virtual StringRef getRangeSection() = 0;
   virtual StringRef getPubNamesSection() = 0;
   virtual StringRef getGnuPubNamesSection() = 0;
 
   // Sections for DWARF5 split dwarf proposal.
-  virtual StringRef getInfoDWOSection() = 0;
+  virtual const Section &getInfoDWOSection() = 0;
   virtual StringRef getAbbrevDWOSection() = 0;
   virtual StringRef getStringDWOSection() = 0;
   virtual StringRef getStringOffsetDWOSection() = 0;
   virtual StringRef getRangeDWOSection() = 0;
   virtual StringRef getAddrSection() = 0;
-  virtual const RelocAddrMap &infoDWORelocMap() const = 0;
 
   static bool isSupportedVersion(unsigned version) {
     return version == 2 || version == 3 || version == 4;
@@ -155,23 +156,19 @@ class DWARFContextInMemory : public DWARFContext {
   virtual void anchor();
   bool IsLittleEndian;
   uint8_t AddressSize;
-  RelocAddrMap InfoRelocMap;
-  RelocAddrMap LocRelocMap;
-  RelocAddrMap LineRelocMap;
-  StringRef InfoSection;
+  Section InfoSection;
   StringRef AbbrevSection;
-  StringRef LocSection;
+  Section LocSection;
   StringRef ARangeSection;
   StringRef DebugFrameSection;
-  StringRef LineSection;
+  Section LineSection;
   StringRef StringSection;
   StringRef RangeSection;
   StringRef PubNamesSection;
   StringRef GnuPubNamesSection;
 
   // Sections for DWARF5 split dwarf proposal.
-  RelocAddrMap InfoDWORelocMap;
-  StringRef InfoDWOSection;
+  Section InfoDWOSection;
   StringRef AbbrevDWOSection;
   StringRef StringDWOSection;
   StringRef StringOffsetDWOSection;
@@ -185,22 +182,19 @@ public:
   ~DWARFContextInMemory();
   virtual bool isLittleEndian() const { return IsLittleEndian; }
   virtual uint8_t getAddressSize() const { return AddressSize; }
-  virtual const RelocAddrMap &infoRelocMap() const { return InfoRelocMap; }
-  virtual const RelocAddrMap &locRelocMap() const { return LocRelocMap; }
-  virtual const RelocAddrMap &lineRelocMap() const { return LineRelocMap; }
-  virtual StringRef getInfoSection() { return InfoSection; }
+  virtual const Section &getInfoSection() { return InfoSection; }
   virtual StringRef getAbbrevSection() { return AbbrevSection; }
-  virtual StringRef getLocSection() { return LocSection; }
+  virtual const Section &getLocSection() { return LocSection; }
   virtual StringRef getARangeSection() { return ARangeSection; }
   virtual StringRef getDebugFrameSection() { return DebugFrameSection; }
-  virtual StringRef getLineSection() { return LineSection; }
+  virtual const Section &getLineSection() { return LineSection; }
   virtual StringRef getStringSection() { return StringSection; }
   virtual StringRef getRangeSection() { return RangeSection; }
   virtual StringRef getPubNamesSection() { return PubNamesSection; }
   virtual StringRef getGnuPubNamesSection() { return GnuPubNamesSection; }
 
   // Sections for DWARF5 split dwarf proposal.
-  virtual StringRef getInfoDWOSection() { return InfoDWOSection; }
+  virtual const Section &getInfoDWOSection() { return InfoDWOSection; }
   virtual StringRef getAbbrevDWOSection() { return AbbrevDWOSection; }
   virtual StringRef getStringDWOSection() { return StringDWOSection; }
   virtual StringRef getStringOffsetDWOSection() {
@@ -210,9 +204,6 @@ public:
   virtual StringRef getAddrSection() {
     return AddrSection;
   }
-  virtual const RelocAddrMap &infoDWORelocMap() const {
-    return InfoDWORelocMap;
-  }
 };
 
 }