llvm-dwarfdump: implement --find for .apple_names

This patch implements the dwarfdump option --find=<name>.  This option
looks for a DIE in the accelerator tables and dumps it if found.  This
initial patch only adds support for .apple_names to keep the review
small, adding the other sections and pubnames support should be
trivial though.

Differential Revision: https://reviews.llvm.org/D38282

llvm-svn: 314439

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/BinaryFormat/Dwarf.cpp b/llvm/lib/BinaryFormat/Dwarf.cpp
index 37c4579ef0f..86e3b02577f 100644
--- a/llvm/lib/BinaryFormat/Dwarf.cpp
+++ b/llvm/lib/BinaryFormat/Dwarf.cpp
@@ -575,3 +575,10 @@ bool llvm::dwarf::isValidFormForVersion(Form F, unsigned Version,
   }
   return ExtensionsOk;
 }
+
+uint32_t llvm::dwarf::djbHash(StringRef Buffer) {
+  uint32_t H = 5381;
+  for (char C : Buffer.bytes())
+    H = ((H << 5) + H) + C;
+  return H;
+}