ELFObjectWriter: deduplicate suffices in strtab

We already do this for shstrtab, so might as well do it for strtab. This
extracts the string table building code into a separate class. The idea
is to use it for other object formats too.

I mostly wanted to do this for the general principle, but it does save a
little bit on object file size. I tried this on a clang bootstrap and
saved 0.54% on the sum of object file sizes (1.14 MB out of 212 MB for
a release build).

Differential Revision: http://reviews.llvm.org/D3533

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207670 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 4 deletions

diff --git a/tools/yaml2obj/yaml2elf.cpp b/tools/yaml2obj/yaml2elf.cpp
index acbac9c605..c78e1dbe77 100644
--- a/tools/yaml2obj/yaml2elf.cpp
+++ b/tools/yaml2obj/yaml2elf.cpp
@@ -30,10 +30,8 @@ using namespace llvm;
 // This class has a deliberately small interface, since a lot of
 // implementation variation is possible.
 //
-// TODO: Use an ordered container with a suffix-based comparison in order
-// to deduplicate suffixes. std::map<> with a custom comparator is likely
-// to be the simplest implementation, but a suffix trie could be more
-// suitable for the job.
+// TODO: Use the StringTable builder from lib/Object instead, since it
+// will deduplicate suffixes.
 namespace {
 class StringTableBuilder {
   /// \brief Indices of strings currently present in `Buf`.