[PECOFF] Make ReaderCOFF more robust against planned identity_magic() changes.

No functionality change.

llvm-svn: 194560

1 files changed, 7 insertions, 3 deletions

diff --git a/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp b/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp
index 40bf988a987..18026a19478 100644
--- a/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp
+++ b/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp
@@ -758,9 +758,9 @@ public:
 
     if (fileType == llvm::sys::fs::file_magic::windows_resource)
       return convertAndParseResourceFile(mb, result);
-    if (fileType == llvm::sys::fs::file_magic::coff_object)
-      return parseCOFFFile(mb, result);
-    return lld::coff::parseCOFFImportLibrary(_context, mb, result);
+    if (isImportLibrary(magic))
+      return lld::coff::parseCOFFImportLibrary(_context, mb, result);
+    return parseCOFFFile(mb, result);
   }
 
 private:
@@ -929,6 +929,10 @@ private:
     return error_code::success();
   }
 
+  static bool isImportLibrary(StringRef magic) {
+    return magic[2] == (char)0xff && magic[3] == (char)0xff;
+  }
+
   PECOFFLinkingContext &_PECOFFLinkingContext;
   mutable BumpPtrStringSaver _stringSaver;
 };