[llvm-objcopy] Ignore -B --binary-architecture=

GNU objcopy documents that -B is only useful with architecture-less
input (i.e. "binary" or "ihex"). After D67144, -O defaults to -I, and
-B is essentially a NOP.

* If -O is binary/ihex, GNU objcopy ignores -B.
* If -O is elf*, -B provides the e_machine field in GNU objcopy.

So to convert a blob to an ELF, `-I binary -B i386:x86-64 -O elf64-x86-64` has to be specified.

`-I binary -B i386:x86-64 -O elf64-x86-64` creates an ELF with its
e_machine field set to EM_NONE in GNU objcopy, but a regular x86_64 ELF
in elftoolchain elfcopy. Follow the elftoolchain approach (ignoring -B)
to simplify code. Users that expect their command line portable should
specify -B.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D67215

llvm-svn: 371914

1 files changed, 2 insertions, 4 deletions

diff --git a/llvm/test/tools/llvm-objcopy/ELF/binary-input-error.test b/llvm/test/tools/llvm-objcopy/ELF/binary-input-error.test
index d0dd50a4194..40ce3edce01 100644
--- a/llvm/test/tools/llvm-objcopy/ELF/binary-input-error.test
+++ b/llvm/test/tools/llvm-objcopy/ELF/binary-input-error.test
@@ -1,6 +1,4 @@
 # RUN: echo abcd > %t.txt
 
-# RUN: not llvm-objcopy -I binary -B xyz %t.txt %t.o 2>&1 \
-# RUN:   | FileCheck %s --check-prefix=BAD-BINARY-ARCH
-
-# BAD-BINARY-ARCH: invalid architecture: 'xyz'
+## -B is ignored.
+# RUN: llvm-objcopy -I binary -B xyz %t.txt %t.o