Temporarily revert r270070

It broke buildbot:
http://lab.llvm.org:8011/builders/clang-s390x-linux/builds/4817/steps/ninja%20check%201/logs/stdio

Actually it is just because D20273 not yet commited, but these 2 were crossing with each other,
and I`ll better find the way to land them separatelly soon.

Initial commit message:

[llvm-mc] - Teach llvm-mc to generate compressed debug sections in zlib style.

Before this patch llvm-mc generated zlib-gnu styled sections. 
That means no SHF_COMPRESSED flag was set, magic 'zlib' signature
was used in combination with full size field. Sections were renamed to "*.z*".
This patch reimplements the compression style to zlib one as zlib-gnu looks
to be depricated everywhere.

Differential revision: http://reviews.llvm.org/D20331

llvm-svn: 270075

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index aa15ff69904..67463e583d7 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/lib/MC/MCContext.cpp
@@ -285,6 +285,22 @@ MCSectionMachO *MCContext::getMachOSection(StringRef Segment, StringRef Section,
              Segment, Section, TypeAndAttributes, Reserved2, Kind, Begin);
 }
 
+void MCContext::renameELFSection(MCSectionELF *Section, StringRef Name) {
+  StringRef GroupName;
+  if (const MCSymbol *Group = Section->getGroup())
+    GroupName = Group->getName();
+
+  unsigned UniqueID = Section->getUniqueID();
+  ELFUniquingMap.erase(
+      ELFSectionKey{Section->getSectionName(), GroupName, UniqueID});
+  auto I = ELFUniquingMap.insert(std::make_pair(
+                                     ELFSectionKey{Name, GroupName, UniqueID},
+                                     Section))
+               .first;
+  StringRef CachedName = I->first.SectionName;
+  const_cast<MCSectionELF *>(Section)->setSectionName(CachedName);
+}
+
 MCSectionELF *MCContext::createELFRelSection(StringRef Name, unsigned Type,
                                              unsigned Flags, unsigned EntrySize,
                                              const MCSymbolELF *Group,