[yaml2obj] - Add a way to describe content of the SHT_GNU_verneed section with "Content".

There is no way to set raw content for SHT_GNU_verneed section.
This patch implements it.

Differential revision: https://reviews.llvm.org/D70816

2 files changed, 28 insertions, 10 deletions

diff --git a/llvm/lib/ObjectYAML/ELFEmitter.cpp b/llvm/lib/ObjectYAML/ELFEmitter.cpp
index 069e3c19523..37eeb01fb09 100644
--- a/llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -1036,15 +1036,24 @@ void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
   typedef typename ELFT::Vernaux Elf_Vernaux;
 
   auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+  SHeader.sh_info = Section.Info;
+
+  if (Section.Content) {
+    SHeader.sh_size = writeContent(OS, Section.Content, None);
+    return;
+  }
+
+  if (!Section.VerneedV)
+    return;
 
   uint64_t AuxCnt = 0;
-  for (size_t I = 0; I < Section.VerneedV.size(); ++I) {
-    const ELFYAML::VerneedEntry &VE = Section.VerneedV[I];
+  for (size_t I = 0; I < Section.VerneedV->size(); ++I) {
+    const ELFYAML::VerneedEntry &VE = (*Section.VerneedV)[I];
 
     Elf_Verneed VerNeed;
     VerNeed.vn_version = VE.Version;
     VerNeed.vn_file = DotDynstr.getOffset(VE.File);
-    if (I == Section.VerneedV.size() - 1)
+    if (I == Section.VerneedV->size() - 1)
       VerNeed.vn_next = 0;
     else
       VerNeed.vn_next =
@@ -1069,9 +1078,8 @@ void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
     }
   }
 
-  SHeader.sh_size = Section.VerneedV.size() * sizeof(Elf_Verneed) +
+  SHeader.sh_size = Section.VerneedV->size() * sizeof(Elf_Verneed) +
                     AuxCnt * sizeof(Elf_Vernaux);
-  SHeader.sh_info = Section.Info;
 }
 
 template <class ELFT>
@@ -1344,10 +1352,12 @@ template <class ELFT> void ELFState<ELFT>::finalizeStrings() {
   // add strings to .dynstr section.
   for (const ELFYAML::Chunk *Sec : Doc.getSections()) {
     if (auto VerNeed = dyn_cast<ELFYAML::VerneedSection>(Sec)) {
-      for (const ELFYAML::VerneedEntry &VE : VerNeed->VerneedV) {
-        DotDynstr.add(VE.File);
-        for (const ELFYAML::VernauxEntry &Aux : VE.AuxV)
-          DotDynstr.add(Aux.Name);
+      if (VerNeed->VerneedV) {
+        for (const ELFYAML::VerneedEntry &VE : *VerNeed->VerneedV) {
+          DotDynstr.add(VE.File);
+          for (const ELFYAML::VernauxEntry &Aux : VE.AuxV)
+            DotDynstr.add(Aux.Name);
+        }
       }
     } else if (auto VerDef = dyn_cast<ELFYAML::VerdefSection>(Sec)) {
       if (VerDef->Entries)
diff --git a/llvm/lib/ObjectYAML/ELFYAML.cpp b/llvm/lib/ObjectYAML/ELFYAML.cpp
index ebda4cca97c..2a9d51486f6 100644
--- a/llvm/lib/ObjectYAML/ELFYAML.cpp
+++ b/llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -1086,7 +1086,8 @@ static void sectionMapping(IO &IO, ELFYAML::SymverSection &Section) {
 static void sectionMapping(IO &IO, ELFYAML::VerneedSection &Section) {
   commonSectionMapping(IO, Section);
   IO.mapRequired("Info", Section.Info);
-  IO.mapRequired("Dependencies", Section.VerneedV);
+  IO.mapOptional("Dependencies", Section.VerneedV);
+  IO.mapOptional("Content", Section.Content);
 }
 
 static void sectionMapping(IO &IO, ELFYAML::RelocationSection &Section) {
@@ -1427,6 +1428,13 @@ StringRef MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::validate(
     return {};
   }
 
+  if (const auto *VD = dyn_cast<ELFYAML::VerneedSection>(C.get())) {
+    if (VD->VerneedV && VD->Content)
+      return "SHT_GNU_verneed: \"Dependencies\" and \"Content\" can't be used "
+             "together";
+    return {};
+  }
+
   return {};
 }