Add LC_BUILD_VERSION load command

Summary:
Add a new load command LC_BUILD_VERSION. It is a generic version of
LC_*_VERSION_MIN load_command used on Apple platforms. Instead of having
a seperate load command for each platform, LC_BUILD_VERSION is recording
platform info as an enum. It also records SDK version, min_os, and tools
that used to build the binary.

rdar://problem/29781291

Reviewers: enderby

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29044

llvm-svn: 292824

1 files changed, 15 insertions, 0 deletions

diff --git a/llvm/tools/yaml2obj/yaml2macho.cpp b/llvm/tools/yaml2obj/yaml2macho.cpp
index 6a27a7f64c0..92b736e5298 100644
--- a/llvm/tools/yaml2obj/yaml2macho.cpp
+++ b/llvm/tools/yaml2obj/yaml2macho.cpp
@@ -180,6 +180,21 @@ size_t writeLoadCommandData<MachO::rpath_command>(MachOYAML::LoadCommand &LC,
   return writePayloadString(LC, OS);
 }
 
+template <>
+size_t writeLoadCommandData<MachO::build_version_command>(
+    MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) {
+  size_t BytesWritten = 0;
+  for (const auto &T : LC.Tools) {
+    struct MachO::build_tool_version tool = T;
+    if (IsLittleEndian != sys::IsLittleEndianHost)
+      MachO::swapStruct(tool);
+    OS.write(reinterpret_cast<const char *>(&tool),
+             sizeof(MachO::build_tool_version));
+    BytesWritten += sizeof(MachO::build_tool_version);
+  }
+  return BytesWritten;
+}
+
 void ZeroFillBytes(raw_ostream &OS, size_t Size) {
   std::vector<uint8_t> FillData;
   FillData.insert(FillData.begin(), Size, 0);