[DWARF] - Refactoring: localize handling of relocations in a single p…

…lace.

This is splitted from D32228,
currently DWARF parsers code has few places that applied relocations values manually.
These places has similar duplicated code. Patch introduces separate method that can be
used to obtain relocated value. That helps to reduce code and simplifies things.

Differential revision: https://reviews.llvm.org/D32284

llvm-svn: 300956

llvm/include/llvm/DebugInfo/DWARF/DWARFContext.h

@@ -50,6 +50,11 @@ class raw_ostream;
 // entire size of the debug info sections.
 typedef DenseMap<uint64_t, std::pair<uint8_t, int64_t>> RelocAddrMap;
 
+/// 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);
+
 /// DWARFContext
 /// This data structure is the top level entity that deals with dwarf debug
 /// information parsing. The actual data is supplied through pure virtual

llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp

@@ -9,6 +9,7 @@
 
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
 #include "llvm/Support/Dwarf.h"
@@ -112,10 +113,8 @@ LLVM_DUMP_METHOD void DWARFAcceleratorTable::dump(raw_ostream &OS) const {
         continue;
       }
       while (AccelSection.isValidOffsetForDataOfSize(DataOffset, 4)) {
-        unsigned StringOffset = AccelSection.getU32(&DataOffset);
-        RelocAddrMap::const_iterator Reloc = Relocs.find(DataOffset-4);
-        if (Reloc != Relocs.end())
-          StringOffset += Reloc->second.second;
+        unsigned StringOffset =
+            getRelocatedValue(AccelSection, 4, &DataOffset, &Relocs);
         if (!StringOffset)
           break;
         OS << format("    Name: %08x \"%s\"\n", StringOffset,

llvm/lib/DebugInfo/DWARF/DWARFContext.cpp

@@ -56,6 +56,16 @@ typedef DWARFDebugLine::LineTable DWARFLineTable;
 typedef DILineInfoSpecifier::FileLineInfoKind FileLineInfoKind;
 typedef DILineInfoSpecifier::FunctionNameKind FunctionNameKind;
 
+uint64_t llvm::getRelocatedValue(const DataExtractor &Data, uint32_t Size,
+                                 uint32_t *Off, const RelocAddrMap *Relocs) {
+  if (!Relocs)
+    return Data.getUnsigned(Off, Size);
+  RelocAddrMap::const_iterator AI = Relocs->find(*Off);
+  if (AI == Relocs->end())
+    return Data.getUnsigned(Off, Size);
+  return Data.getUnsigned(Off, Size) + AI->second.second;
+}
+
 static void dumpAccelSection(raw_ostream &OS, StringRef Name,
                              const DWARFSection& Section, StringRef StringSection,
                              bool LittleEndian) {

llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp

@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/SmallString.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
 #include "llvm/Support/Dwarf.h"
@@ -302,16 +303,9 @@ bool DWARFDebugLine::LineTable::parse(DataExtractor debug_line_data,
         // relocatable address. All of the other statement program opcodes
         // that affect the address register add a delta to it. This instruction
         // stores a relocatable value into it instead.
-        {
-          // If this address is in our relocation map, apply the relocation.
-          RelocAddrMap::const_iterator AI = RMap->find(*offset_ptr);
-          if (AI != RMap->end()) {
-            const std::pair<uint8_t, int64_t> &R = AI->second;
-            State.Row.Address =
-                debug_line_data.getAddress(offset_ptr) + R.second;
-          } else
-            State.Row.Address = debug_line_data.getAddress(offset_ptr);
-        }
+        State.Row.Address =
+            getRelocatedValue(debug_line_data, debug_line_data.getAddressSize(),
+                              offset_ptr, RMap);
         break;
 
       case DW_LNE_define_file:

llvm/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp

@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/StringRef.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
 #include "llvm/Support/Dwarf.h"
@@ -48,18 +49,10 @@ void DWARFDebugLoc::parse(DataExtractor data, unsigned AddressSize) {
     // 2.6.2 Location Lists
     // A location list entry consists of:
     while (true) {
+      // A beginning and ending address offsets.
       Entry E;
-      RelocAddrMap::const_iterator AI = RelocMap.find(Offset);
-      // 1. A beginning address offset. ...
-      E.Begin = data.getUnsigned(&Offset, AddressSize);
-      if (AI != RelocMap.end())
-        E.Begin += AI->second.second;
-
-      AI = RelocMap.find(Offset);
-      // 2. An ending address offset. ...
-      E.End = data.getUnsigned(&Offset, AddressSize);
-      if (AI != RelocMap.end())
-        E.End += AI->second.second;
+      E.Begin = getRelocatedValue(data, AddressSize, &Offset, &RelocMap);
+      E.End = getRelocatedValue(data, AddressSize, &Offset, &RelocMap);
 
       // The end of any given location list is marked by an end of list entry,
       // which consists of a 0 for the beginning address offset and a 0 for the

llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp

@@ -334,11 +334,8 @@ bool DWARFFormValue::extractValue(const DataExtractor &data,
           (Form == DW_FORM_addr)
               ? U->getAddressByteSize()
               : U->getRefAddrByteSize();
-      RelocAddrMap::const_iterator AI = U->getRelocMap()->find(*offset_ptr);
-      if (AI != U->getRelocMap()->end()) {
-        Value.uval = data.getUnsigned(offset_ptr, AddrSize) + AI->second.second;
-      } else
-        Value.uval = data.getUnsigned(offset_ptr, AddrSize);
+      Value.uval =
+          getRelocatedValue(data, AddrSize, offset_ptr, U->getRelocMap());
       break;
     }
     case DW_FORM_exprloc:
@@ -376,12 +373,8 @@ bool DWARFFormValue::extractValue(const DataExtractor &data,
     case DW_FORM_ref_sup4:
     case DW_FORM_strx4:
     case DW_FORM_addrx4: {
-      Value.uval = data.getU32(offset_ptr);
-      if (!U)
-        break;
-      RelocAddrMap::const_iterator AI = U->getRelocMap()->find(*offset_ptr-4);
-      if (AI != U->getRelocMap()->end())
-        Value.uval += AI->second.second;
+      const RelocAddrMap* RelocMap = U ? U->getRelocMap() : nullptr;
+      Value.uval = getRelocatedValue(data, 4, offset_ptr, RelocMap);
       break;
     }
     case DW_FORM_data8:
@@ -411,11 +404,8 @@ bool DWARFFormValue::extractValue(const DataExtractor &data,
     case DW_FORM_strp_sup: {
       if (!U)
         return false;
-      RelocAddrMap::const_iterator AI = U->getRelocMap()->find(*offset_ptr);
-      uint8_t Size = U->getDwarfOffsetByteSize();
-      Value.uval = data.getUnsigned(offset_ptr, Size);
-      if (AI != U->getRelocMap()->end())
-        Value.uval += AI->second.second;
+      Value.uval = getRelocatedValue(data, U->getDwarfOffsetByteSize(),
+                                     offset_ptr, U->getRelocMap());
       break;
     }
     case DW_FORM_flag_present: