[obj2yaml/yaml2obj] Add SHT_GROUP support.

This adds section group support to the tools obj2yaml and yaml2obj.

llvm-svn: 230124

1 files changed, 44 insertions, 0 deletions

diff --git a/llvm/tools/yaml2obj/yaml2elf.cpp b/llvm/tools/yaml2obj/yaml2elf.cpp
index c8d4b887576..5d4c26379be 100644
--- a/llvm/tools/yaml2obj/yaml2elf.cpp
+++ b/llvm/tools/yaml2obj/yaml2elf.cpp
@@ -131,6 +131,8 @@ class ELFState {
   bool writeSectionContent(Elf_Shdr &SHeader,
                            const ELFYAML::RelocationSection &Section,
                            ContiguousBlobAccumulator &CBA);
+  bool writeSectionContent(Elf_Shdr &SHeader, const ELFYAML::Group &Group,
+                           ContiguousBlobAccumulator &CBA);
 
   // - SHT_NULL entry (placed first, i.e. 0'th entry)
   // - symbol table (.symtab) (placed third to last)
@@ -223,6 +225,16 @@ bool ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
 
       if (!writeSectionContent(SHeader, *S, CBA))
         return false;
+    } else if (auto S = dyn_cast<ELFYAML::Group>(Sec.get())) {
+      unsigned SymIdx;
+      if (SymN2I.lookup(S->Info, SymIdx)) {
+        errs() << "error: Unknown symbol referenced: '" << S->Info
+               << "' at YAML section '" << S->Name << "'.\n";
+        return false;
+      }
+      SHeader.sh_info = SymIdx;
+      if (!writeSectionContent(SHeader, *S, CBA))
+        return false;
     } else
       llvm_unreachable("Unknown section type");
 
@@ -370,6 +382,38 @@ ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
   return true;
 }
 
+template <class ELFT>
+bool ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
+                                         const ELFYAML::Group &Section,
+                                         ContiguousBlobAccumulator &CBA) {
+  typedef typename object::ELFFile<ELFT>::Elf_Word Elf_Word;
+  if (Section.Type != llvm::ELF::SHT_GROUP) {
+    errs() << "error: Invalid section type.\n";
+    return false;
+  }
+
+  SHeader.sh_entsize = sizeof(Elf_Word);
+  SHeader.sh_size = SHeader.sh_entsize * Section.Members.size();
+
+  auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset);
+
+  for (auto member : Section.Members) {
+    Elf_Word SIdx;
+    unsigned int sectionIndex = 0;
+    if (member.sectionNameOrType == "GRP_COMDAT")
+      sectionIndex = llvm::ELF::GRP_COMDAT;
+    else if (SN2I.lookup(member.sectionNameOrType, sectionIndex)) {
+      errs() << "error: Unknown section referenced: '"
+             << member.sectionNameOrType << "' at YAML section' "
+             << Section.Name << "\n";
+      return false;
+    }
+    SIdx = sectionIndex;
+    OS.write((const char *)&SIdx, sizeof(SIdx));
+  }
+  return true;
+}
+
 template <class ELFT> bool ELFState<ELFT>::buildSectionIndex() {
   SN2I.addName(".symtab", getDotSymTabSecNo());
   SN2I.addName(".strtab", getDotStrTabSecNo());