objdump: identify WoA WinCOFF/ARM correctly

Since LLVM currently only supports WinCOFF, assume that the input is WinCOFF
rather than another type of COFF file (ECOFF/XCOFF).  If the architecture is
detected as thumb (e.g. the file has a IMAGE_FILE_MACHINE_ARMNT magic) then use
a triple of thumbv7-windows.

This allows for objdump to properly handle WoA object files without having to
specify the target triple manually.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206446 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 0 deletions

diff --git a/tools/llvm-objdump/llvm-objdump.cpp b/tools/llvm-objdump/llvm-objdump.cpp
index 9d043f18c2..a4b94c9b6a 100644
--- a/tools/llvm-objdump/llvm-objdump.cpp
+++ b/tools/llvm-objdump/llvm-objdump.cpp
@@ -167,6 +167,12 @@ static const Target *getTarget(const ObjectFile *Obj = NULL) {
       // the best we can do here is indicate that it is mach-o.
       if (Obj->isMachO())
         TheTriple.setObjectFormat(Triple::MachO);
+
+      if (Obj->isCOFF()) {
+        const auto COFFObj = dyn_cast<COFFObjectFile>(Obj);
+        if (COFFObj->getArch() == Triple::thumb)
+          TheTriple.setTriple("thumbv7-windows");
+      }
     }
   } else
     TheTriple.setTriple(Triple::normalize(TripleName));