Fixed bugs in llvm-obdump while parsing Mach-O files from malformed archives
that caused aborts.  This was because of the characters of the ‘Size’ field in
the archive header did not contain decimal characters.

rdar://22983603

llvm-svn: 250117
diff --git a/llvm/lib/Object/Archive.cpp b/llvm/lib/Object/Archive.cpp
index 42fec39..b0e0881 100644
--- a/llvm/lib/Object/Archive.cpp
+++ b/llvm/lib/Object/Archive.cpp
@@ -50,6 +50,13 @@
   return Ret;
 }
 
+bool ArchiveMemberHeader::isSizeValid() const {
+  uint32_t Ret;
+  if (llvm::StringRef(Size, sizeof(Size)).rtrim(" ").getAsInteger(10, Ret))
+    return false;
+  return true;
+}
+
 sys::fs::perms ArchiveMemberHeader::getAccessMode() const {
   unsigned Ret;
   if (StringRef(AccessMode, sizeof(AccessMode)).rtrim(" ").getAsInteger(8, Ret))
@@ -89,6 +96,11 @@
 
   uint64_t Size = sizeof(ArchiveMemberHeader);
   Data = StringRef(Start, Size);
+  // Check to make sure the size is valid.
+  const ArchiveMemberHeader *Header =
+    reinterpret_cast<const ArchiveMemberHeader *>(Data.data());
+  if (!Header->isSizeValid())
+    return;
   if (!isThinMember()) {
     Size += getRawSize();
     Data = StringRef(Start, Size);