This patch extends the libLLVMDebugInfo which contains a minimalistic DWARF parser:
1) DIContext is now able to return function name for a given instruction address (besides file/line info).
2) llvm-dwarfdump accepts flag --functions that prints the function name (if address is specified by --address flag).
3) test case that checks the basic functionality of llvm-dwarfdump added

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159512 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/DebugInfo/DWARFCompileUnit.h b/lib/DebugInfo/DWARFCompileUnit.h
index d916729..dc558da 100644
--- a/lib/DebugInfo/DWARFCompileUnit.h
+++ b/lib/DebugInfo/DWARFCompileUnit.h
@@ -104,6 +104,11 @@
 
   void buildAddressRangeTable(DWARFDebugAranges *debug_aranges,
                               bool clear_dies_if_already_not_parsed);
+  /// getFunctionDIEForAddress - Returns pointer to parsed subprogram DIE,
+  /// address ranges of which contain the provided address,
+  /// or NULL if there is no such subprogram. The pointer
+  /// is valid until DWARFCompileUnit::clear() or clearDIEs() is called.
+  const DWARFDebugInfoEntryMinimal *getFunctionDIEForAddress(int64_t address);
 };
 
 }