[yaml2obj] - Make .symtab to be not mandatory section for SHT_REL[A] section.
Before this change .symtab section was required for SHT_REL[A] section
declarations. yaml2obj automatically defined it in case when YAML document
did not have it.
With this change it is now possible to produce an object that
has a relocation section, but has no symbol table.
It simplifies the code and also it is inline with how we handle Link fields
for another special sections.
Differential revision: https://reviews.llvm.org/D69260
diff --git a/llvm/lib/ObjectYAML/ELFEmitter.cpp b/llvm/lib/ObjectYAML/ELFEmitter.cpp
index 6a4e00c..64b5cd4 100644
--- a/llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -205,17 +205,10 @@
ELFState<ELFT>::ELFState(ELFYAML::Object &D, yaml::ErrorHandler EH)
: Doc(D), ErrHandler(EH) {
StringSet<> DocSections;
- for (std::unique_ptr<ELFYAML::Section> &D : Doc.Sections) {
+ for (std::unique_ptr<ELFYAML::Section> &D : Doc.Sections)
if (!D->Name.empty())
DocSections.insert(D->Name);
- // Some sections wants to link to .symtab by default.
- // That means we want to create the symbol table for them.
- if (D->Type == llvm::ELF::SHT_REL || D->Type == llvm::ELF::SHT_RELA)
- if (!Doc.Symbols && D->Link.empty())
- Doc.Symbols.emplace();
- }
-
// Insert SHT_NULL section implicitly when it is not defined in YAML.
if (Doc.Sections.empty() || Doc.Sections.front()->Type != ELF::SHT_NULL)
Doc.Sections.insert(
@@ -742,8 +735,9 @@
SHeader.sh_size = SHeader.sh_entsize * Section.Relocations.size();
// For relocation section set link to .symtab by default.
- if (Section.Link.empty())
- SHeader.sh_link = SN2I.get(".symtab");
+ unsigned Link = 0;
+ if (Section.Link.empty() && SN2I.lookup(".symtab", Link))
+ SHeader.sh_link = Link;
if (!Section.RelocatableSec.empty())
SHeader.sh_info = toSectionIndex(Section.RelocatableSec, Section.Name);