[yaml2macho] Removing asserts in favor of explicit yaml parse error

32-bit Mach headers don't have reserved fields. When generating the
mapping for 32-bit headers leaving off the reserved field will result in
parse errors if the field is present in the yaml.

Added a CHECK-NOT line to ensure that mach_header.yaml isn't adding a
reserved field, and a test to ensure that the parser error gets hit with
32-bit headers.

llvm-svn: 273623

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/ObjectYAML/MachOYAML.cpp b/llvm/lib/ObjectYAML/MachOYAML.cpp
index b4e808552df..d13c84eb04f 100644
--- a/llvm/lib/ObjectYAML/MachOYAML.cpp
+++ b/llvm/lib/ObjectYAML/MachOYAML.cpp
@@ -14,6 +14,7 @@
 #include "llvm/ObjectYAML/MachOYAML.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Format.h"
+#include "llvm/Support/MachO.h"
 
 #include <string.h> // For memcpy, memset and strnlen.
 
@@ -79,8 +80,9 @@ void MappingTraits<MachOYAML::FileHeader>::mapping(
   IO.mapRequired("ncmds", FileHdr.ncmds);
   IO.mapRequired("sizeofcmds", FileHdr.sizeofcmds);
   IO.mapRequired("flags", FileHdr.flags);
-  IO.mapOptional("reserved", FileHdr.reserved,
-                 static_cast<llvm::yaml::Hex32>(0xDEADBEEFu));
+  if (FileHdr.magic == MachO::MH_MAGIC_64 ||
+      FileHdr.magic == MachO::MH_CIGAM_64)
+    IO.mapRequired("reserved", FileHdr.reserved);
 }
 
 void MappingTraits<MachOYAML::Object>::mapping(IO &IO,