[yaml2obj] - Allow overriding sh_offset field from the YAML.

Some of our test cases are using objects which
has sections with a broken sh_offset field.

There was no way to set it from YAML until this patch.

Differential revision: https://reviews.llvm.org/D63879

llvm-svn: 364898

2 files changed, 11 insertions, 0 deletions

diff --git a/llvm/tools/obj2yaml/elf2yaml.cpp b/llvm/tools/obj2yaml/elf2yaml.cpp
index 804101f2dee..7404bae2a08 100644
--- a/llvm/tools/obj2yaml/elf2yaml.cpp
+++ b/llvm/tools/obj2yaml/elf2yaml.cpp
@@ -360,6 +360,8 @@ std::error_code ELFDumper<ELFT>::dumpRelocation(const RelT *Rel,
 template <class ELFT>
 std::error_code ELFDumper<ELFT>::dumpCommonSection(const Elf_Shdr *Shdr,
                                                    ELFYAML::Section &S) {
+  // Dump fields. We do not dump the ShOffset field. When not explicitly
+  // set, the value is set by yaml2obj automatically.
   S.Type = Shdr->sh_type;
   if (Shdr->sh_flags)
     S.Flags = static_cast<ELFYAML::ELF_SHF>(Shdr->sh_flags);
diff --git a/llvm/tools/yaml2obj/yaml2elf.cpp b/llvm/tools/yaml2obj/yaml2elf.cpp
index e093ed8d72f..735057f6e7d 100644
--- a/llvm/tools/yaml2obj/yaml2elf.cpp
+++ b/llvm/tools/yaml2obj/yaml2elf.cpp
@@ -269,6 +269,11 @@ bool ELFState<ELFT>::initImplicitHeader(ELFState<ELFT> &State,
                                   YAMLSec);
   else
     return false;
+
+  // Override the sh_offset field if requested.
+  if (YAMLSec && YAMLSec->ShOffset)
+    Header.sh_offset = *YAMLSec->ShOffset;
+
   return true;
 }
 
@@ -358,6 +363,10 @@ bool ELFState<ELFT>::initSectionHeaders(ELFState<ELFT> &State,
         return false;
     } else
       llvm_unreachable("Unknown section type");
+
+    // Override the sh_offset field if requested.
+    if (Sec && Sec->ShOffset)
+      SHeader.sh_offset = *Sec->ShOffset;
   }
 
   return true;