Index: llvm/trunk/test/tools/llvm-objcopy/ELF/archive-unknown-members.test
===================================================================
--- llvm/trunk/test/tools/llvm-objcopy/ELF/archive-unknown-members.test
+++ llvm/trunk/test/tools/llvm-objcopy/ELF/archive-unknown-members.test
@@ -0,0 +1,45 @@
+## Show that llvm-objcopy and llvm-strip emit errors when attempting to modify
+## archives containing unrecognized files, and do not modify anything. We use
+## --strip-debug so that the section should be removed, and a difference
+## detectable, if the file were modified.
+
+# RUN: yaml2obj %s -o %t.o
+# RUN: rm -f %t.a
+# RUN: llvm-ar rc %t.a %t.o %s
+# RUN: cp %t.a %t1.a
+# RUN: cp %t.a %t2.a
+
+# RUN: not llvm-objcopy --strip-debug %t1.a 2>&1 | FileCheck %s -DARCHIVE=%t1.a
+# RUN: not llvm-strip --strip-debug %t2.a 2>&1 | FileCheck %s -DARCHIVE=%t2.a
+## Verify that the archive was not modified, if any member couldn't be recognised.
+# RUN: cmp %t.a %t1.a
+# RUN: cmp %t.a %t2.a
+
+# CHECK: error: '[[ARCHIVE]](archive-unknown-members.test)': The file was not recognized as a valid object file
+
+# RUN: rm -f %t.thin1.a %t.thin2.a
+# RUN: cp %t.o %t1.o
+# RUN: cp %t.o %t2.o
+# RUN: llvm-ar rcT %t.thin1.a %t1.o %s
+# RUN: llvm-ar rcT %t.thin2.a %t2.o %s
+
+# RUN: not llvm-objcopy --strip-debug %t.thin1.a 2>&1 \
+# RUN:   | FileCheck %s --check-prefix=THIN -DARCHIVE=%t.thin1.a -DMEMBER=%s
+# RUN: not llvm-strip --strip-debug %t.thin2.a 2>&1 \
+# RUN:   | FileCheck %s --check-prefix=THIN -DARCHIVE=%t.thin2.a -DMEMBER=%s
+## Verify that the first member was not modified, if a later member could not
+## be recognised.
+# RUN: cmp %t.o %t1.o
+# RUN: cmp %t.o %t2.o
+
+# THIN: error: '[[ARCHIVE]]([[MEMBER]])': The file was not recognized as a valid object file
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name: .debug_foo
+    Type: SHT_PROGBITS
Index: llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp
===================================================================
--- llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp
+++ llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp
@@ -154,17 +154,17 @@
   std::vector<NewArchiveMember> NewArchiveMembers;
   Error Err = Error::success();
   for (const Archive::Child &Child : Ar.children(Err)) {
-    Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
-    if (!ChildOrErr)
-      return createFileError(Ar.getFileName(), ChildOrErr.takeError());
-    Binary *Bin = ChildOrErr->get();
-
     Expected<StringRef> ChildNameOrErr = Child.getName();
     if (!ChildNameOrErr)
       return createFileError(Ar.getFileName(), ChildNameOrErr.takeError());
 
+    Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
+    if (!ChildOrErr)
+      return createFileError(Ar.getFileName() + "(" + *ChildNameOrErr + ")",
+                             ChildOrErr.takeError());
+
     MemBuffer MB(ChildNameOrErr.get());
-    if (Error E = executeObjcopyOnBinary(Config, *Bin, MB))
+    if (Error E = executeObjcopyOnBinary(Config, *ChildOrErr->get(), MB))
       return E;
 
     Expected<NewArchiveMember> Member =