Hi all,

After merging the tip tree, today's linux-next build (perf) failed
like this:

In file included from tools/include/linux/build_bug.h:5,
                 from tools/include/linux/kernel.h:8,
                 from util/intel-pt-decoder/intel-pt-insn-decoder.c:7:
util/intel-pt-decoder/../../../arch/x86/lib/insn.c: In function '__insn_get_emulate_prefix':
tools/include/linux/compiler.h:37:38: error: nested extern declaration of '__compiletime_assert_0' [-Werror=nested-externs]
   37 |  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
      |                                      ^~~~~~~~~~~~~~~~~~~~~
tools/include/linux/compiler.h:16:15: note: in definition of macro '__compiletime_assert'
   16 |   extern void prefix ## suffix(void) __compiletime_error(msg); \
      |               ^~~~~~
tools/include/linux/compiler.h:37:2: note: in expansion of macro '_compiletime_assert'
   37 |  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
      |  ^~~~~~~~~~~~~~~~~~~
tools/include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
   39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
      |                                     ^~~~~~~~~~~~~~~~~~
tools/include/linux/build_bug.h:59:21: note: in expansion of macro 'BUILD_BUG_ON_MSG'
   59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
      |                     ^~~~~~~~~~~~~~~~
util/intel-pt-decoder/../../../arch/x86/lib/insn.c:27:3: note: in expansion of macro 'BUILD_BUG'
   27 |   BUILD_BUG(); break;     \
      |   ^~~~~~~~~
util/intel-pt-decoder/../../../arch/x86/lib/insn.c:40:41: note: in expansion of macro 'leXX_to_cpu'
   40 |  ({ t r = *(t*)((insn)->next_byte + n); leXX_to_cpu(t, r); })
      |                                         ^~~~~~~~~~~
util/intel-pt-decoder/../../../arch/x86/lib/insn.c:46:61: note: in expansion of macro '__peek_nbyte_next'
   46 |  ({ if (unlikely(!validate_next(t, insn, n))) goto err_out; __peek_nbyte_next(t, insn, n); })
      |                                                             ^~~~~~~~~~~~~~~~~
util/intel-pt-decoder/../../../arch/x86/lib/insn.c:86:7: note: in expansion of macro 'peek_nbyte_next'
   86 |   if (peek_nbyte_next(insn_byte_t, insn, i) != prefix[i])
      |       ^~~~~~~~~~~~~~~

Caused by commit

  2a522b53c470 ("x86/insn: Support big endian cross-compiles")

I have reverted commits

a23b701ae9b3 objtool: Rework header include paths
1b4998c364bc objtool: Fix x86 orc generation on big endian cross compiles
317664a7fcc9 objtool: Fix reloc generation on big endian cross compiles
2a522b53c470 x86/insn: Support big endian cross-compiles
2486baae2cf6 objtool: Allow nested externs to enable BUILD_BUG()

for today.

This is a PowerPC LE native build of tools/perf.

-- 
Cheers,
Stephen Rothwell