[DWARF] NFC: DWARFDataExtractor combines relocs with DataExtractor.

Requires callers to directly associate relocations with a DataExtractor
used to read data from a DWARF section, which helps a callee not make
assumptions about which section it is reading.
This is the next step in reducing DWARFFormValue's dependence on DWARFUnit.

Differential Revision: https://reviews.llvm.org/D34704



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306699 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h

@@ -12,8 +12,8 @@
 
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/BinaryFormat/Dwarf.h"
+#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
-#include "llvm/Support/DataExtractor.h"
 #include <cstdint>
 #include <utility>
 
@@ -41,14 +41,13 @@ class DWARFAcceleratorTable {
 
   struct Header Hdr;
   struct HeaderData HdrData;
-  DataExtractor AccelSection;
+  DWARFDataExtractor AccelSection;
   DataExtractor StringSection;
-  const RelocAddrMap& Relocs;
 
 public:
-  DWARFAcceleratorTable(DataExtractor AccelSection, DataExtractor StringSection,
-                        const RelocAddrMap &Relocs)
-    : AccelSection(AccelSection), StringSection(StringSection), Relocs(Relocs) {}
+  DWARFAcceleratorTable(const DWARFDataExtractor &AccelSection,
+                        DataExtractor StringSection)
+      : AccelSection(AccelSection), StringSection(StringSection) {}
 
   bool extract();
   uint32_t getNumBuckets();

include/llvm/DebugInfo/DWARF/DWARFCompileUnit.h

@@ -20,8 +20,8 @@ class DWARFCompileUnit : public DWARFUnit {
   DWARFCompileUnit(DWARFContext &Context, const DWARFSection &Section,
                    const DWARFDebugAbbrev *DA, const DWARFSection *RS,
                    StringRef SS, const DWARFSection &SOS,
-                   const DWARFSection *AOS, StringRef LS, bool LE, bool IsDWO,
-                   const DWARFUnitSectionBase &UnitSection,
+                   const DWARFSection *AOS, const DWARFSection &LS, bool LE,
+                   bool IsDWO, const DWARFUnitSectionBase &UnitSection,
                    const DWARFUnitIndex::Entry *Entry)
       : DWARFUnit(Context, Section, DA, RS, SS, SOS, AOS, LS, LE, IsDWO,
                   UnitSection, Entry) {}

include/llvm/DebugInfo/DWARF/DWARFContext.h

@@ -45,12 +45,6 @@ class DataExtractor;
 class MemoryBuffer;
 class raw_ostream;
 
-/// Reads a value from data extractor and applies a relocation to the result if
-/// one exists for the given offset.
-uint64_t getRelocatedValue(const DataExtractor &Data, uint32_t Size,
-                           uint32_t *Off, const RelocAddrMap *Relocs,
-                           uint64_t *SecNdx = nullptr);
-
 /// DWARFContext
 /// This data structure is the top level entity that deals with dwarf debug
 /// information parsing. The actual data is supplied through pure virtual

include/llvm/DebugInfo/DWARF/DWARFDataExtractor.h

@@ -0,0 +1,48 @@
+//===- DWARFDataExtractor.h -------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_DWARFDATAEXTRACTOR_H
+#define LLVM_DEBUGINFO_DWARFDATAEXTRACTOR_H
+
+#include "llvm/DebugInfo/DWARF/DWARFSection.h"
+#include "llvm/Support/DataExtractor.h"
+
+namespace llvm {
+
+/// A DataExtractor (typically for an in-memory copy of an object-file section)
+/// plus a relocation map for that section, if there is one.
+class DWARFDataExtractor : public DataExtractor {
+  const RelocAddrMap *RelocMap = nullptr;
+public:
+  /// Constructor for the normal case of extracting data from a DWARF section.
+  /// The DWARFSection's lifetime must be at least as long as the extractor's.
+  DWARFDataExtractor(const DWARFSection &Section, bool IsLittleEndian,
+                     uint8_t AddressSize)
+    : DataExtractor(Section.Data, IsLittleEndian, AddressSize),
+      RelocMap(&Section.Relocs) {}
+
+  /// Constructor for cases when there are no relocations.
+  DWARFDataExtractor(StringRef Data, bool IsLittleEndian, uint8_t AddressSize)
+    : DataExtractor(Data, IsLittleEndian, AddressSize) {}
+
+  /// Extracts a value and applies a relocation to the result if
+  /// one exists for the given offset.
+  uint64_t getRelocatedValue(uint32_t Size, uint32_t *Off,
+                             uint64_t *SectionIndex = nullptr) const;
+
+  /// Extracts an address-sized value and applies a relocation to the result if
+  /// one exists for the given offset.
+  uint64_t getRelocatedAddress(uint32_t *Off, uint64_t *SecIx = nullptr) const {
+    return getRelocatedValue(getAddressSize(), Off, SecIx);
+  }
+};
+
+} // end namespace llvm
+
+#endif // LLVM_DEBUGINFO_DWARFDATAEXTRACTOR_H

include/llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h

@@ -12,6 +12,7 @@
 
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
+#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 #include <cstdint>
 
 namespace llvm {
@@ -40,8 +41,7 @@ class DWARFDebugInfoEntry {
 
   /// High performance extraction should use this call.
   bool extractFast(const DWARFUnit &U, uint32_t *OffsetPtr,
-                   const DataExtractor &DebugInfoData,
-                   uint32_t UEndOffset,
+                   const DWARFDataExtractor &DebugInfoData, uint32_t UEndOffset,
                    uint32_t Depth);
 
   uint32_t getOffset() const { return Offset; }

include/llvm/DebugInfo/DWARF/DWARFDebugLine.h

@@ -12,9 +12,9 @@
 
 #include "llvm/ADT/StringRef.h"
 #include "llvm/DebugInfo/DIContext.h"
+#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
-#include "llvm/Support/DataExtractor.h"
 #include <cstdint>
 #include <map>
 #include <string>
@@ -26,9 +26,6 @@ class raw_ostream;
 
 class DWARFDebugLine {
 public:
-  DWARFDebugLine(const RelocAddrMap *LineInfoRelocMap)
-      : RelocMap(LineInfoRelocMap) {}
-
   struct FileNameEntry {
     FileNameEntry() = default;
 
@@ -98,7 +95,7 @@ class DWARFDebugLine {
 
     void clear();
     void dump(raw_ostream &OS) const;
-    bool parse(DataExtractor DebugLineData, uint32_t *OffsetPtr);
+    bool parse(const DWARFDataExtractor &DebugLineData, uint32_t *OffsetPtr);
   };
 
   /// Standard .debug_line state machine structure.
@@ -220,8 +217,7 @@ class DWARFDebugLine {
     void clear();
 
     /// Parse prologue and all rows.
-    bool parse(DataExtractor DebugLineData, const RelocAddrMap *RMap,
-               uint32_t *OffsetPtr);
+    bool parse(const DWARFDataExtractor &DebugLineData, uint32_t *OffsetPtr);
 
     using RowVector = std::vector<Row>;
     using RowIter = RowVector::const_iterator;
@@ -238,7 +234,7 @@ class DWARFDebugLine {
   };
 
   const LineTable *getLineTable(uint32_t Offset) const;
-  const LineTable *getOrParseLineTable(DataExtractor DebugLineData,
+  const LineTable *getOrParseLineTable(const DWARFDataExtractor &DebugLineData,
                                        uint32_t Offset);
 
 private:
@@ -261,7 +257,6 @@ class DWARFDebugLine {
   using LineTableIter = LineTableMapTy::iterator;
   using LineTableConstIter = LineTableMapTy::const_iterator;
 
-  const RelocAddrMap *RelocMap;
   LineTableMapTy LineTableMap;
 };
 

include/llvm/DebugInfo/DWARF/DWARFDebugLoc.h

@@ -11,8 +11,8 @@
 #define LLVM_DEBUGINFO_DWARF_DWARFDEBUGLOC_H
 
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
-#include "llvm/Support/DataExtractor.h"
 #include <cstdint>
 
 namespace llvm {
@@ -45,18 +45,13 @@ class DWARFDebugLoc {
   /// the locations in which the variable is stored.
   LocationLists Locations;
 
-  /// A map used to resolve binary relocations.
-  const RelocAddrMap &RelocMap;
-
 public:
-  DWARFDebugLoc(const RelocAddrMap &LocRelocMap) : RelocMap(LocRelocMap) {}
-
   /// Print the location lists found within the debug_loc section.
   void dump(raw_ostream &OS) const;
 
   /// Parse the debug_loc section accessible via the 'data' parameter using the
-  /// specified address size to interpret the address ranges.
-  void parse(DataExtractor data, unsigned AddressSize);
+  /// address size also given in 'data' to interpret the address ranges.
+  void parse(const DWARFDataExtractor &data);
 };
 
 class DWARFDebugLocDWO {

include/llvm/DebugInfo/DWARF/DWARFDebugRangeList.h

@@ -10,8 +10,8 @@
 #ifndef LLVM_DEBUGINFO_DWARF_DWARFDEBUGRANGELIST_H
 #define LLVM_DEBUGINFO_DWARF_DWARFDEBUGRANGELIST_H
 
+#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
-#include "llvm/Support/DataExtractor.h"
 #include <cassert>
 #include <cstdint>
 #include <vector>
@@ -79,7 +79,7 @@ class DWARFDebugRangeList {
 
   void clear();
   void dump(raw_ostream &OS) const;
-  bool extract(DataExtractor data, uint32_t *offset_ptr, const RelocAddrMap& Relocs);
+  bool extract(const DWARFDataExtractor &data, uint32_t *offset_ptr);
   const std::vector<RangeListEntry> &getEntries() { return Entries; }
 
   /// getAbsoluteRanges - Returns absolute address ranges defined by this range

include/llvm/DebugInfo/DWARF/DWARFFormValue.h

@@ -14,7 +14,7 @@
 #include "llvm/ADT/None.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/BinaryFormat/Dwarf.h"
-#include "llvm/Support/DataExtractor.h"
+#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 #include <cstdint>
 
 namespace llvm {
@@ -105,14 +105,13 @@ class DWARFFormValue {
 
   /// Extracts a value in \p Data at offset \p *OffsetPtr.
   ///
-  /// The passed DWARFUnit is allowed to be nullptr, in which
-  /// case no relocation processing will be performed and some
+  /// The passed DWARFUnit is allowed to be nullptr, in which case some
   /// kind of forms that depend on Unit information are disallowed.
-  /// \param Data The DataExtractor to use.
-  /// \param OffsetPtr The offset within DataExtractor where the data starts.
+  /// \param Data The DWARFDataExtractor to use.
+  /// \param OffsetPtr The offset within \p Data where the data starts.
   /// \param U The optional DWARFUnit supplying information for some forms.
   /// \returns whether the extraction succeeded.
-  bool extractValue(const DataExtractor &Data, uint32_t *OffsetPtr,
+  bool extractValue(const DWARFDataExtractor &Data, uint32_t *OffsetPtr,
                     const DWARFUnit *U);
 
   bool isInlinedCStr() const {

include/llvm/DebugInfo/DWARF/DWARFTypeUnit.h

@@ -32,7 +32,7 @@ class DWARFTypeUnit : public DWARFUnit {
   DWARFTypeUnit(DWARFContext &Context, const DWARFSection &Section,
                 const DWARFDebugAbbrev *DA, const DWARFSection *RS,
                 StringRef SS, const DWARFSection &SOS, const DWARFSection *AOS,
-                StringRef LS, bool LE, bool IsDWO,
+                const DWARFSection &LS, bool LE, bool IsDWO,
                 const DWARFUnitSectionBase &UnitSection,
                 const DWARFUnitIndex::Entry *Entry)
       : DWARFUnit(Context, Section, DA, RS, SS, SOS, AOS, LS, LE, IsDWO,

include/llvm/DebugInfo/DWARF/DWARFUnit.h

@@ -58,7 +58,7 @@ class DWARFUnitSectionBase {
   virtual void parseImpl(DWARFContext &Context, const DWARFSection &Section,
                          const DWARFDebugAbbrev *DA, const DWARFSection *RS,
                          StringRef SS, const DWARFSection &SOS,
-                         const DWARFSection *AOS, StringRef LS,
+                         const DWARFSection *AOS, const DWARFSection &LS,
                          bool isLittleEndian, bool isDWO) = 0;
 };
 
@@ -91,7 +91,7 @@ class DWARFUnitSection final : public SmallVector<std::unique_ptr<UnitType>, 1>,
   void parseImpl(DWARFContext &Context, const DWARFSection &Section,
                  const DWARFDebugAbbrev *DA, const DWARFSection *RS,
                  StringRef SS, const DWARFSection &SOS, const DWARFSection *AOS,
-                 StringRef LS, bool LE, bool IsDWO) override {
+                 const DWARFSection &LS, bool LE, bool IsDWO) override {
     if (Parsed)
       return;
     const auto &Index = getDWARFUnitIndex(Context, UnitType::Section);
@@ -118,7 +118,7 @@ class DWARFUnit {
   const DWARFDebugAbbrev *Abbrev;
   const DWARFSection *RangeSection;
   uint32_t RangeSectionBase;
-  StringRef LineSection;
+  const DWARFSection &LineSection;
   StringRef StringSection;
   const DWARFSection &StringOffsetSection;
   uint64_t StringOffsetSectionBase = 0;
@@ -166,15 +166,16 @@ class DWARFUnit {
 public:
   DWARFUnit(DWARFContext &Context, const DWARFSection &Section,
             const DWARFDebugAbbrev *DA, const DWARFSection *RS, StringRef SS,
-            const DWARFSection &SOS, const DWARFSection *AOS, StringRef LS,
-            bool LE, bool IsDWO, const DWARFUnitSectionBase &UnitSection,
+            const DWARFSection &SOS, const DWARFSection *AOS,
+            const DWARFSection &LS, bool LE, bool IsDWO,
+            const DWARFUnitSectionBase &UnitSection,
             const DWARFUnitIndex::Entry *IndexEntry = nullptr);
 
   virtual ~DWARFUnit();
 
   DWARFContext& getContext() const { return Context; }
 
-  StringRef getLineSection() const { return LineSection; }
+  const DWARFSection &getLineSection() const { return LineSection; }
   StringRef getStringSection() const { return StringSection; }
   const DWARFSection &getStringOffsetSection() const {
     return StringOffsetSection;
@@ -196,9 +197,9 @@ class DWARFUnit {
   bool getAddrOffsetSectionItem(uint32_t Index, uint64_t &Result) const;
   bool getStringOffsetSectionItem(uint32_t Index, uint64_t &Result) const;
 
-  DataExtractor getDebugInfoExtractor() const {
-    return DataExtractor(InfoSection.Data, isLittleEndian,
-                         getAddressByteSize());
+  DWARFDataExtractor getDebugInfoExtractor() const {
+    return DWARFDataExtractor(InfoSection, isLittleEndian,
+                              getAddressByteSize());
   }
 
   DataExtractor getStringExtractor() const {

lib/DebugInfo/DWARF/CMakeLists.txt

@@ -3,6 +3,7 @@ add_llvm_library(LLVMDebugInfoDWARF
   DWARFAcceleratorTable.cpp
   DWARFCompileUnit.cpp
   DWARFContext.cpp
+  DWARFDataExtractor.cpp
   DWARFDebugAbbrev.cpp
   DWARFDebugArangeSet.cpp
   DWARFDebugAranges.cpp

lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp

@@ -121,8 +121,7 @@ LLVM_DUMP_METHOD void DWARFAcceleratorTable::dump(raw_ostream &OS) const {
         continue;
       }
       while (AccelSection.isValidOffsetForDataOfSize(DataOffset, 4)) {
-        unsigned StringOffset =
-            getRelocatedValue(AccelSection, 4, &DataOffset, &Relocs);
+        unsigned StringOffset = AccelSection.getRelocatedValue(4, &DataOffset);
         if (!StringOffset)
           break;
         OS << format("    Name: %08x \"%s\"\n", StringOffset,