Handle relocations that don't point to symbols.

In ELF (as in MachO), not all relocations point to symbols. Represent this
properly by using a symbol_iterator instead of a SymbolRef. Update llvm-readobj
ELF's dumper to handle relocatios without symbols.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183284 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 15 insertions, 16 deletions

diff --git a/include/llvm/Object/COFF.h b/include/llvm/Object/COFF.h
index 1127263..c0efbba 100644
--- a/include/llvm/Object/COFF.h
+++ b/include/llvm/Object/COFF.h
@@ -243,8 +243,7 @@ protected:
                                           uint64_t &Res) const;
   virtual error_code getRelocationOffset(DataRefImpl Rel,
                                          uint64_t &Res) const;
-  virtual error_code getRelocationSymbol(DataRefImpl Rel,
-                                         SymbolRef &Res) const;
+  virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const;
   virtual error_code getRelocationType(DataRefImpl Rel,
                                        uint64_t &Res) const;
   virtual error_code getRelocationTypeName(DataRefImpl Rel,
diff --git a/include/llvm/Object/ELF.h b/include/llvm/Object/ELF.h
index 592dbae..a6c545e 100644
--- a/include/llvm/Object/ELF.h
+++ b/include/llvm/Object/ELF.h
@@ -716,8 +716,7 @@ protected:
                                           uint64_t &Res) const;
   virtual error_code getRelocationOffset(DataRefImpl Rel,
                                          uint64_t &Res) const;
-  virtual error_code getRelocationSymbol(DataRefImpl Rel,
-                                         SymbolRef &Res) const;
+  virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const;
   virtual error_code getRelocationType(DataRefImpl Rel,
                                        uint64_t &Res) const;
   virtual error_code getRelocationTypeName(DataRefImpl Rel,
@@ -1503,9 +1502,9 @@ error_code ELFObjectFile<ELFT>::getRelocationNext(DataRefImpl Rel,
   return object_error::success;
 }
 
-template<class ELFT>
-error_code ELFObjectFile<ELFT>::getRelocationSymbol(DataRefImpl Rel,
-                                                    SymbolRef &Result) const {
+template <class ELFT>
+symbol_iterator
+ELFObjectFile<ELFT>::getRelocationSymbol(DataRefImpl Rel) const {
   uint32_t symbolIdx;
   const Elf_Shdr *sec = getRelSection(Rel);
   switch (sec->sh_type) {
@@ -1520,6 +1519,9 @@ error_code ELFObjectFile<ELFT>::getRelocationSymbol(DataRefImpl Rel,
       break;
     }
   }
+  if (!symbolIdx)
+    return end_symbols();
+
   DataRefImpl SymbolData;
   IndexMap_t::const_iterator it =
       SymbolTableSectionsIndexMap.find(sec->sh_link);
@@ -1527,8 +1529,7 @@ error_code ELFObjectFile<ELFT>::getRelocationSymbol(DataRefImpl Rel,
     report_fatal_error("Relocation symbol table not found!");
   SymbolData.d.a = symbolIdx;
   SymbolData.d.b = it->second;
-  Result = SymbolRef(SymbolData, this);
-  return object_error::success;
+  return symbol_iterator(SymbolRef(SymbolData, this));
 }
 
 template<class ELFT>
diff --git a/include/llvm/Object/MachO.h b/include/llvm/Object/MachO.h
index bedf5c1..f3ba8ef 100644
--- a/include/llvm/Object/MachO.h
+++ b/include/llvm/Object/MachO.h
@@ -72,7 +72,7 @@ public:
                                        RelocationRef &Res) const;
   virtual error_code getRelocationAddress(DataRefImpl Rel, uint64_t &Res) const;
   virtual error_code getRelocationOffset(DataRefImpl Rel, uint64_t &Res) const;
-  virtual error_code getRelocationSymbol(DataRefImpl Rel, SymbolRef &Res) const;
+  virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const;
   virtual error_code getRelocationType(DataRefImpl Rel, uint64_t &Res) const;
   virtual error_code getRelocationTypeName(DataRefImpl Rel,
                                            SmallVectorImpl<char> &Result) const;
diff --git a/include/llvm/Object/ObjectFile.h b/include/llvm/Object/ObjectFile.h
index ba1bb69..f434d63 100644
--- a/include/llvm/Object/ObjectFile.h
+++ b/include/llvm/Object/ObjectFile.h
@@ -85,6 +85,7 @@ inline bool operator<(const DataRefImpl &a, const DataRefImpl &b) {
 }
 
 class SymbolRef;
+typedef content_iterator<SymbolRef> symbol_iterator;
 
 /// RelocationRef - This is a value type class that represents a single
 /// relocation in the list of relocations in the object file.
@@ -103,7 +104,7 @@ public:
 
   error_code getAddress(uint64_t &Result) const;
   error_code getOffset(uint64_t &Result) const;
-  error_code getSymbol(SymbolRef &Result) const;
+  symbol_iterator getSymbol() const;
   error_code getType(uint64_t &Result) const;
 
   /// @brief Indicates whether this relocation should hidden when listing
@@ -236,7 +237,6 @@ public:
 
   DataRefImpl getRawDataRefImpl() const;
 };
-typedef content_iterator<SymbolRef> symbol_iterator;
 
 /// LibraryRef - This is a value type class that represents a single library in
 /// the list of libraries needed by a shared or dynamic object.
@@ -334,8 +334,7 @@ protected:
                                           uint64_t &Res) const =0;
   virtual error_code getRelocationOffset(DataRefImpl Rel,
                                          uint64_t &Res) const =0;
-  virtual error_code getRelocationSymbol(DataRefImpl Rel,
-                                         SymbolRef &Res) const = 0;
+  virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
   virtual error_code getRelocationType(DataRefImpl Rel,
                                        uint64_t &Res) const = 0;
   virtual error_code getRelocationTypeName(DataRefImpl Rel,
@@ -566,8 +565,8 @@ inline error_code RelocationRef::getOffset(uint64_t &Result) const {
   return OwningObject->getRelocationOffset(RelocationPimpl, Result);
 }
 
-inline error_code RelocationRef::getSymbol(SymbolRef &Result) const {
-  return OwningObject->getRelocationSymbol(RelocationPimpl, Result);
+inline symbol_iterator RelocationRef::getSymbol() const {
+  return OwningObject->getRelocationSymbol(RelocationPimpl);
 }
 
 inline error_code RelocationRef::getType(uint64_t &Result) const {