[PATCH] D86542: [llvm/Object] - Make dyn_cast<XCOFFObjectFile> work as it should.

[George Rimar via Phabricator via llvm-commits]

grimar created this revision.
grimar added reviewers: jhenderson, MaskRay.
Herald added subscribers: rupprecht, sunfish.
Herald added a project: LLVM.
grimar requested review of this revision.
Herald added a subscriber: aheejin.

Currently, `dyn_cast<XCOFFObjectFile>` always does cast and returns a pointer,
even when we pass `ELF`/`Wasm`/`Mach-O` or `COFF` instead of `XCOFF`.

It happens because `XCOFFObjectFile` class does not implement `classof`.
In this patch I've reordered dyn_cast's in `llvm-objdump` code to
group `COFF` and `XCOFF` together, what allows to trigger the issue.


https://reviews.llvm.org/D86542

Files:
  llvm/include/llvm/Object/XCOFFObjectFile.h
  llvm/tools/llvm-objdump/llvm-objdump.cpp


Index: llvm/tools/llvm-objdump/llvm-objdump.cpp
===================================================================
--- llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -537,12 +537,12 @@
     return getELFRelocationValueString(ELF, Rel, Result);
   if (auto *COFF = dyn_cast<COFFObjectFile>(Obj))
     return getCOFFRelocationValueString(COFF, Rel, Result);
+  if (auto *XCOFF = dyn_cast<XCOFFObjectFile>(Obj))
+    return getXCOFFRelocationValueString(XCOFF, Rel, Result);
   if (auto *Wasm = dyn_cast<WasmObjectFile>(Obj))
     return getWasmRelocationValueString(Wasm, Rel, Result);
   if (auto *MachO = dyn_cast<MachOObjectFile>(Obj))
     return getMachORelocationValueString(MachO, Rel, Result);
-  if (auto *XCOFF = dyn_cast<XCOFFObjectFile>(Obj))
-    return getXCOFFRelocationValueString(XCOFF, Rel, Result);
   llvm_unreachable("unknown object file format");
 }
 
Index: llvm/include/llvm/Object/XCOFFObjectFile.h
===================================================================
--- llvm/include/llvm/Object/XCOFFObjectFile.h
+++ llvm/include/llvm/Object/XCOFFObjectFile.h
@@ -372,6 +372,8 @@
 
   Expected<ArrayRef<XCOFFRelocation32>>
   relocations(const XCOFFSectionHeader32 &) const;
+
+  static bool classof(const Binary *B) { return B->isXCOFF(); }
 }; // XCOFFObjectFile
 
 class XCOFFSymbolRef {


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