Reapply: Allow yaml2obj to order implicit sections for ELF

Summary:
This change allows yaml input to control the order of implicitly added sections
(`.symtab`, `.strtab`, `.shstrtab`). The order is controlled by adding a
placeholder section of the given name to the Sections field.

This change is to support changes in D39582, where it is desirable to control
the location of the `.dynsym` section.

This reapplied version fixes:
  1. use of a function call within an assert
  2. failing lld test which has an unnamed section

Additionally, one more test to cover the unnamed section failure.

Reviewers: compnerd, jakehehrlich

Reviewed By: jakehehrlich

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39749

llvm-svn: 317646

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/ObjectYAML/ELFYAML.cpp b/llvm/lib/ObjectYAML/ELFYAML.cpp
index ada9ff89b8e..38940376de2 100644
--- a/llvm/lib/ObjectYAML/ELFYAML.cpp
+++ b/llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -388,7 +388,7 @@ void ScalarEnumerationTraits<ELFYAML::ELF_SHT>::enumeration(
 #define ECase(X) IO.enumCase(Value, #X, ELF::X)
   ECase(SHT_NULL);
   ECase(SHT_PROGBITS);
-  // No SHT_SYMTAB. Use the top-level `Symbols` key instead.
+  ECase(SHT_SYMTAB);
   // FIXME: Issue a diagnostic with this information.
   ECase(SHT_STRTAB);
   ECase(SHT_RELA);