ObjectFile: Add a method to check whether a section contains a symbol.

- No ELF or COFF implementation yet, I don't have a way to test that.
  Should be straightforward to add though.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135288 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 0ec5cda..26a6e13 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -60,6 +60,8 @@
   virtual error_code getSectionSize(DataRefImpl Sec, uint64_t &Res) const;
   virtual error_code getSectionContents(DataRefImpl Sec, StringRef &Res) const;
   virtual error_code isSectionText(DataRefImpl Sec, bool &Res) const;
+  virtual error_code sectionContainsSymbol(DataRefImpl DRI, DataRefImpl S,
+                                           bool &Result) const;
 
 private:
   MachOObject *MachOObj;
@@ -383,6 +385,21 @@
   return object_error::success;
 }
 
+error_code MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec,
+                                                  DataRefImpl Symb,
+                                                  bool &Result) const {
+  if (MachOObj->is64Bit()) {
+    InMemoryStruct<macho::Symbol64TableEntry> Entry;
+    getSymbol64TableEntry(Symb, Entry);
+    Result = Entry->SectionIndex == 1 + Sec.d.a + Sec.d.b;
+  } else {
+    InMemoryStruct<macho::SymbolTableEntry> Entry;
+    getSymbolTableEntry(Symb, Entry);
+    Result = Entry->SectionIndex == 1 + Sec.d.a + Sec.d.b;
+  }
+  return object_error::success;
+}
+
 ObjectFile::section_iterator MachOObjectFile::begin_sections() const {
   DataRefImpl DRI;
   DRI.d.a = DRI.d.b = 0;