1 files changed, 29 insertions, 2 deletions
diff --git a/ELF/InputSection.cpp b/ELF/InputSection.cpp
index e8cfd21c4c49..466656efbf08 100644
--- a/ELF/InputSection.cpp
+++ b/ELF/InputSection.cpp
@@ -23,6 +23,7 @@
 #include "llvm/Support/Compression.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/Threading.h"
 #include <mutex>
 
 using namespace llvm;
@@ -172,7 +173,8 @@ void InputSectionBase::uncompress() {
   if (Error E = Dec.decompress({OutputBuf, Size}))
     fatal(toString(this) +
           ": decompress failed: " + llvm::toString(std::move(E)));
-  Data = ArrayRef<uint8_t>((uint8_t *)OutputBuf, Size);
+  this->Data = ArrayRef<uint8_t>((uint8_t *)OutputBuf, Size);
+  this->Flags &= ~(uint64_t)SHF_COMPRESSED;
 }
 
 uint64_t SectionBase::getOffset(const DefinedRegular &Sym) const {
@@ -293,6 +295,24 @@ bool InputSectionBase::classof(const SectionBase *S) {
   return S->kind() != Output;
 }
 
+void InputSection::copyShtGroup(uint8_t *Buf) {
+  assert(this->Type == SHT_GROUP);
+
+  ArrayRef<uint32_t> From = getDataAs<uint32_t>();
+  uint32_t *To = reinterpret_cast<uint32_t *>(Buf);
+
+  // First entry is a flag word, we leave it unchanged.
+  *To++ = From[0];
+
+  // Here we adjust indices of sections that belong to group as it
+  // might change during linking.
+  ArrayRef<InputSectionBase *> Sections = this->File->getSections();
+  for (uint32_t Val : From.slice(1)) {
+    uint32_t Index = read32(&Val, Config->Endianness);
+    write32(To++, Sections[Index]->OutSec->SectionIndex, Config->Endianness);
+  }
+}
+
 InputSectionBase *InputSection::getRelocatedSection() {
   assert(this->Type == SHT_RELA || this->Type == SHT_REL);
   ArrayRef<InputSectionBase *> Sections = this->File->getSections();
@@ -678,6 +698,13 @@ template <class ELFT> void InputSection::writeTo(uint8_t *Buf) {
     return;
   }
 
+  // If -r is given, linker should keep SHT_GROUP sections. We should fixup
+  // them, see copyShtGroup().
+  if (this->Type == SHT_GROUP) {
+    copyShtGroup(Buf + OutSecOff);
+    return;
+  }
+
   // Copy section contents from source object file to output file
   // and then apply relocations.
   memcpy(Buf + OutSecOff, Data.data(), Data.size());
@@ -866,7 +893,7 @@ const SectionPiece *MergeInputSection::getSectionPiece(uint64_t Offset) const {
 // it is not just an addition to a base output offset.
 uint64_t MergeInputSection::getOffset(uint64_t Offset) const {
   // Initialize OffsetMap lazily.
-  std::call_once(InitOffsetMap, [&] {
+  llvm::call_once(InitOffsetMap, [&] {
     OffsetMap.reserve(Pieces.size());
     for (const SectionPiece &Piece : Pieces)
       OffsetMap[Piece.InputOff] = Piece.OutputOff;