[yaml2obj/obj2yaml] - Make RawContentSection::Content and RawContentSection::Size optional

This is a follow-up for D62809.

Content and Size fields should be optional as was discussed in comments
of the D62809's thread. With that, we can describe a specific string table and
symbol table sections in a more correct way and also show appropriate errors.

The patch adds lots of test cases where the behavior is described in details.

Differential revision: https://reviews.llvm.org/D62957

llvm-svn: 362931

1 files changed, 7 insertions, 4 deletions

diff --git a/llvm/lib/ObjectYAML/ELFYAML.cpp b/llvm/lib/ObjectYAML/ELFYAML.cpp
index 33d011cbd9f..8be86ab4707 100644
--- a/llvm/lib/ObjectYAML/ELFYAML.cpp
+++ b/llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -914,7 +914,7 @@ static void sectionMapping(IO &IO, ELFYAML::DynamicSection &Section) {
 static void sectionMapping(IO &IO, ELFYAML::RawContentSection &Section) {
   commonSectionMapping(IO, Section);
   IO.mapOptional("Content", Section.Content);
-  IO.mapOptional("Size", Section.Size, Hex64(Section.Content.binary_size()));
+  IO.mapOptional("Size", Section.Size);
   IO.mapOptional("Info", Section.Info, Hex64(0));
 }
 
@@ -1042,9 +1042,12 @@ void MappingTraits<std::unique_ptr<ELFYAML::Section>>::mapping(
 StringRef MappingTraits<std::unique_ptr<ELFYAML::Section>>::validate(
     IO &io, std::unique_ptr<ELFYAML::Section> &Section) {
   const auto *RawSection = dyn_cast<ELFYAML::RawContentSection>(Section.get());
-  if (!RawSection || RawSection->Size >= RawSection->Content.binary_size())
-    return StringRef();
-  return "Section size must be greater or equal to the content size";
+  if (!RawSection)
+    return {};
+  if (RawSection->Size && RawSection->Content &&
+      (uint64_t)(*RawSection->Size) < RawSection->Content->binary_size())
+    return "Section size must be greater than or equal to the content size";
+  return {};
 }
 
 namespace {