[llvm-readobj] Dump the COFF image load config

This includes the safe SEH tables and the control flow guard function
table. LLD will emit the guard table soon, and I need a tool that dumps
them for testing.

llvm-svn: 305979

llvm/lib/Object/COFFObjectFile.cpp

@@ -650,6 +650,23 @@ std::error_code COFFObjectFile::initDebugDirectoryPtr() {
   return std::error_code();
 }
 
+std::error_code COFFObjectFile::initLoadConfigPtr() {
+  // Get the RVA of the debug directory. Do nothing if it does not exist.
+  const data_directory *DataEntry;
+  if (getDataDirectory(COFF::LOAD_CONFIG_TABLE, DataEntry))
+    return std::error_code();
+
+  // Do nothing if the RVA is NULL.
+  if (DataEntry->RelativeVirtualAddress == 0)
+    return std::error_code();
+  uintptr_t IntPtr = 0;
+  if (std::error_code EC = getRvaPtr(DataEntry->RelativeVirtualAddress, IntPtr))
+    return EC;
+
+  LoadConfig = (const void *)IntPtr;
+  return std::error_code();
+}
+
 COFFObjectFile::COFFObjectFile(MemoryBufferRef Object, std::error_code &EC)
     : ObjectFile(Binary::ID_COFF, Object), COFFHeader(nullptr),
       COFFBigObjHeader(nullptr), PE32Header(nullptr), PE32PlusHeader(nullptr),
@@ -784,6 +801,9 @@ COFFObjectFile::COFFObjectFile(MemoryBufferRef Object, std::error_code &EC)
   if ((EC = initDebugDirectoryPtr()))
     return;
 
+  if ((EC = initLoadConfigPtr()))
+    return;
+
   EC = std::error_code();
 }