Add a relocation visitor to lib object. This works via caching relocated

values in a map that can be passed to consumers. Add a testcase that
ensures this works for llvm-dwarfdump.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167558 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 32 insertions, 9 deletions

diff --git a/lib/DebugInfo/DIContext.cpp b/lib/DebugInfo/DIContext.cpp
index ead57f9..691a92c 100644
--- a/lib/DebugInfo/DIContext.cpp
+++ b/lib/DebugInfo/DIContext.cpp
@@ -19,8 +19,9 @@ DIContext *DIContext::getDWARFContext(bool isLittleEndian,
                                       StringRef aRangeSection,
                                       StringRef lineSection,
                                       StringRef stringSection,
-                                      StringRef rangeSection) {
+                                      StringRef rangeSection,
+                                      const RelocAddrMap &Map) {
   return new DWARFContextInMemory(isLittleEndian, infoSection, abbrevSection,
                                   aRangeSection, lineSection, stringSection,
-                                  rangeSection);
+                                  rangeSection, Map);
 }
diff --git a/lib/DebugInfo/DWARFContext.h b/lib/DebugInfo/DWARFContext.h
index d10e850..4001792 100644
--- a/lib/DebugInfo/DWARFContext.h
+++ b/lib/DebugInfo/DWARFContext.h
@@ -26,6 +26,7 @@ namespace llvm {
 /// methods that a concrete implementation provides.
 class DWARFContext : public DIContext {
   bool IsLittleEndian;
+  const RelocAddrMap &RelocMap;
 
   SmallVector<DWARFCompileUnit, 1> CUs;
   OwningPtr<DWARFDebugAbbrev> Abbrev;
@@ -38,9 +39,11 @@ class DWARFContext : public DIContext {
   /// Read compile units from the debug_info section and store them in CUs.
   void parseCompileUnits();
 protected:
-  DWARFContext(bool isLittleEndian) : IsLittleEndian(isLittleEndian) {}
+  DWARFContext(bool isLittleEndian, const RelocAddrMap &Map) :
+    IsLittleEndian(isLittleEndian), RelocMap(Map) {}
 public:
   virtual void dump(raw_ostream &OS);
+
   /// Get the number of compile units in this context.
   unsigned getNumCompileUnits() {
     if (CUs.empty())
@@ -70,6 +73,7 @@ public:
       DILineInfoSpecifier Specifier = DILineInfoSpecifier());
 
   bool isLittleEndian() const { return IsLittleEndian; }
+  const RelocAddrMap &relocMap() const { return RelocMap; }
 
   virtual StringRef getInfoSection() = 0;
   virtual StringRef getAbbrevSection() = 0;
@@ -108,8 +112,9 @@ public:
                        StringRef aRangeSection,
                        StringRef lineSection,
                        StringRef stringSection,
-                       StringRef rangeSection)
-    : DWARFContext(isLittleEndian),
+                       StringRef rangeSection,
+                       const RelocAddrMap &Map = RelocAddrMap())
+    : DWARFContext(isLittleEndian, Map),
       InfoSection(infoSection),
       AbbrevSection(abbrevSection),
       ARangeSection(aRangeSection),
diff --git a/lib/DebugInfo/DWARFFormValue.cpp b/lib/DebugInfo/DWARFFormValue.cpp
index c9ecbbb..fea9fd7 100644
--- a/lib/DebugInfo/DWARFFormValue.cpp
+++ b/lib/DebugInfo/DWARFFormValue.cpp
@@ -10,6 +10,7 @@
 #include "DWARFFormValue.h"
 #include "DWARFCompileUnit.h"
 #include "DWARFContext.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/raw_ostream.h"
@@ -98,8 +99,16 @@ DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
     indirect = false;
     switch (Form) {
     case DW_FORM_addr:
-    case DW_FORM_ref_addr:
-      Value.uval = data.getUnsigned(offset_ptr, cu->getAddressByteSize());
+    case DW_FORM_ref_addr: {
+      RelocAddrMap::const_iterator AI
+        = cu->getContext().relocMap().find(*offset_ptr);
+      if (AI != cu->getContext().relocMap().end()) {
+        const std::pair<uint8_t, int64_t> &R = AI->second;
+        Value.uval = R.second;
+        *offset_ptr += R.first;
+      } else
+        Value.uval = data.getUnsigned(offset_ptr, cu->getAddressByteSize());
+    }
       break;
     case DW_FORM_exprloc:
     case DW_FORM_block:
@@ -138,9 +147,17 @@ DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
     case DW_FORM_sdata:
       Value.sval = data.getSLEB128(offset_ptr);
       break;
-    case DW_FORM_strp:
-      Value.uval = data.getU32(offset_ptr);
+    case DW_FORM_strp: {
+      RelocAddrMap::const_iterator AI
+        = cu->getContext().relocMap().find(*offset_ptr);
+      if (AI != cu->getContext().relocMap().end()) {
+        const std::pair<uint8_t, int64_t> &R = AI->second;
+        Value.uval = R.second;
+        *offset_ptr += R.first;
+      } else
+        Value.uval = data.getU32(offset_ptr);
       break;
+    }
     case DW_FORM_udata:
     case DW_FORM_ref_udata:
       Value.uval = data.getULEB128(offset_ptr);