objdump: Better handling of Mach-O universal binaries

Summary:
With Mach-O, there is a flag requirement discrepancy between working with
universal binaries and thin binaries. Many flags that don't require the `-macho`
flag (for example `-private-headers` and `-disassemble`) fail to work on
universal binaries unless `-macho` is given. When this happens, the error
message is unhelpful, stating:

    The file was not recognized as a valid object file.

Which can lead to confusion.

This change allows generic flags to be used on universal binaries with and
without the `-macho` flag. This means flags that can be used for thin files can
be used consistently with fat files too.

To do this, the universal binary support within `ParseInputMachO()` is extracted
into a new function. This new function is called directly from `DumpInput()`
when the input binary is universal. Additionally the `-arch` flag validation in
`ParseInputMachO()` was extracted to be reused.

Reviewers: compnerd

Reviewed By: compnerd

Subscribers: keith, llvm-commits

Differential Revision: https://reviews.llvm.org/D48702

llvm-svn: 338792

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/tools/llvm-objdump/llvm-objdump.h b/llvm/tools/llvm-objdump/llvm-objdump.h
index b2eb6e9d777..65867c25f8c 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.h
+++ b/llvm/tools/llvm-objdump/llvm-objdump.h
@@ -22,6 +22,7 @@ namespace object {
   class COFFObjectFile;
   class COFFImportFile;
   class MachOObjectFile;
+  class MachOUniversalBinary;
   class ObjectFile;
   class Archive;
   class RelocationRef;
@@ -71,6 +72,7 @@ extern cl::opt<DIDumpType> DwarfDumpType;
 void error(std::error_code ec);
 bool RelocAddressLess(object::RelocationRef a, object::RelocationRef b);
 void ParseInputMachO(StringRef Filename);
+void ParseInputMachO(object::MachOUniversalBinary *UB);
 void printCOFFUnwindInfo(const object::COFFObjectFile* o);
 void printMachOUnwindInfo(const object::MachOObjectFile* o);
 void printMachOExportsTrie(const object::MachOObjectFile* o);