[DWARF] - Make collectAddressRanges() return section index in addition to Low/High PC

This change is intended to use for LLD in D33183. 
Problem we have in LLD when building .gdb_index is that we need to know section 
which address range belongs to.

Previously it was solved on LLD side by providing fake section addresses
with use of llvm::LoadedObjectInfo interface. We assigned file offsets as addressed.
Then after obtaining ranges lists, for each range we had to find section ID's.
That not only was slow, but also complicated implementation and was the reason 
of incorrect behavior when
sections share the same offsets, like D33176 shows.

This patch makes DWARF parsers to return section index as well. 
That solves problem mentioned above.

Differential revision: https://reviews.llvm.org/D33184

llvm-svn: 303978

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Object/COFFObjectFile.cpp b/llvm/lib/Object/COFFObjectFile.cpp
index 28531feccfe..7372f24cb9a 100644
--- a/llvm/lib/Object/COFFObjectFile.cpp
+++ b/llvm/lib/Object/COFFObjectFile.cpp
@@ -293,6 +293,10 @@ uint64_t COFFObjectFile::getSectionAddress(DataRefImpl Ref) const {
   return Result;
 }
 
+uint64_t COFFObjectFile::getSectionIndex(DataRefImpl Sec) const {
+  return toSec(Sec) - SectionTable;
+}
+
 uint64_t COFFObjectFile::getSectionSize(DataRefImpl Ref) const {
   return getSectionSize(toSec(Ref));
 }