From 5b54a42c0f1178dbb367866f92cd4efe88710bd6 Mon Sep 17 00:00:00 2001
From: Steven Wu <stevenwu@apple.com>
Date: Mon, 23 Jan 2017 20:07:55 +0000
Subject: 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
---
 llvm/lib/Object/MachOObjectFile.cpp | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

(limited to 'llvm/lib/Object/MachOObjectFile.cpp')

diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index 9a1e368f3a7..f35a3e3ba2f 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -809,6 +809,27 @@ static Error checkNoteCommand(const MachOObjectFile &Obj,
   return Error::success();
 }
 
+static Error
+parseBuildVersionCommand(const MachOObjectFile &Obj,
+                         const MachOObjectFile::LoadCommandInfo &Load,
+                         SmallVectorImpl<const char*> &BuildTools,
+                         uint32_t LoadCommandIndex) {
+  MachO::build_version_command BVC =
+      getStruct<MachO::build_version_command>(Obj, Load.Ptr);
+  if (Load.C.cmdsize !=
+      sizeof(MachO::build_version_command) +
+          BVC.ntools * sizeof(MachO::build_tool_version))
+    return malformedError("load command " + Twine(LoadCommandIndex) +
+                          " LC_BUILD_VERSION_COMMAND has incorrect cmdsize");
+
+  auto Start = Load.Ptr + sizeof(MachO::build_version_command);
+  BuildTools.resize(BVC.ntools);
+  for (unsigned i = 0; i < BVC.ntools; ++i)
+    BuildTools[i] = Start + i * sizeof(MachO::build_tool_version);
+
+  return Error::success();
+}
+
 static Error checkRpathCommand(const MachOObjectFile &Obj,
                                const MachOObjectFile::LoadCommandInfo &Load,
                                uint32_t LoadCommandIndex) {
@@ -1308,6 +1329,9 @@ MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,
     } else if (Load.C.cmd == MachO::LC_NOTE) {
       if ((Err = checkNoteCommand(*this, Load, I, Elements)))
         return;
+    } else if (Load.C.cmd == MachO::LC_BUILD_VERSION) {
+      if ((Err = parseBuildVersionCommand(*this, Load, BuildTools, I)))
+        return;
     } else if (Load.C.cmd == MachO::LC_RPATH) {
       if ((Err = checkRpathCommand(*this, Load, I)))
         return;
@@ -3322,6 +3346,16 @@ MachOObjectFile::getNoteLoadCommand(const LoadCommandInfo &L) const {
   return getStruct<MachO::note_command>(*this, L.Ptr);
 }
 
+MachO::build_version_command
+MachOObjectFile::getBuildVersionLoadCommand(const LoadCommandInfo &L) const {
+  return getStruct<MachO::build_version_command>(*this, L.Ptr);
+}
+
+MachO::build_tool_version
+MachOObjectFile::getBuildToolVersion(unsigned index) const {
+  return getStruct<MachO::build_tool_version>(*this, BuildTools[index]);
+}
+
 MachO::dylib_command
 MachOObjectFile::getDylibIDLoadCommand(const LoadCommandInfo &L) const {
   return getStruct<MachO::dylib_command>(*this, L.Ptr);
-- 
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