[binutils-gdb] Fix "maintenance selftest" printing stray instructions

[Pedro Alves <palves at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=b1ace6bdc2063f3dcf46172db98bb3474b6e1121

commit b1ace6bdc2063f3dcf46172db98bb3474b6e1121
Author: Pedro Alves <palves@redhat.com>
Date:   Thu Feb 2 23:27:57 2017 +0000

    Fix "maintenance selftest" printing stray instructions
    
    The "maintenance selftest" command is printing odd bits of stray
    instructions like:
    
    ~~~
    brkwarning: A handler for the OS ABI "GNU/Linux" is not built into this configuration
    of GDB.  Attempting to continue with the default HS settings.
    
    
    brkmov  r0, #0mov       r0, #0mov       r0, #0mov       r0, #0mov       r0, #0mov       r0, #0mov       r0, #0mov       r0, #0mov       r0, #0mov       r0, #0mov       r0, #0mov   r0, #0mov       r0, #0mov       r0, #0mov       r0, #0breakbreakbreakbreakbreakbreakbreakbreakbreakbreakbreakbreakbreakbreakbreakbreakbreakbreakbreakM3.L = 0xffff;/* ( -1) M3=0x0xffff(65535) */break 8break 8warning: A handler for the OS ABI "GNU/Linux" is not built into this configuration
    of GDB.  Attempting to continue with the default cris:common_v10_v32 settings.
    ~~~
    
    etc.  Those appear because here:
    
      class gdb_disassembler_test : public gdb_disassembler
      {
      public:
    
        const bool verbose = false;
    
        explicit gdb_disassembler_test (struct gdbarch *gdbarch,
    				    const gdb_byte *insn,
    				    size_t len)
          : gdb_disassembler (gdbarch,
    			  (verbose ? gdb_stdout : &null_stream),
    			  gdb_disassembler_test::read_memory),
    
    
    specifically in this line:
    
    			  (verbose ? gdb_stdout : &null_stream),
    
    "verbose" has not been initialized yet, because the order of
    initialization is base classes first, then members.  I.e. "verbose" is
    only initialized after the base constructor is called.  Since the
    gdb_disassembler_test object is created on the stack, "verbose" has
    garbage at that point.  If the gargage is non-zero, then we end up
    with the gdb_disassembler_test's stream incorrectly pointing to
    gdb_stdout.
    
    gdb/ChangeLog:
    2017-02-02  Pedro Alves  <palves@redhat.com>
    
    	* disasm-selftests.c (print_one_insn_test): Move the "verbose"
    	field out of gdb_disassembler_test and make it static.

Diff:
---
 gdb/disasm-selftests.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/gdb/disasm-selftests.c b/gdb/disasm-selftests.c
index 7d0b006..9eb80b4 100644
--- a/gdb/disasm-selftests.c
+++ b/gdb/disasm-selftests.c
@@ -102,13 +102,12 @@ print_one_insn_test (struct gdbarch *gdbarch)
   /* Test gdb_disassembler for a given gdbarch by reading data from a
      pre-allocated buffer.  If you want to see the disassembled
      instruction printed to gdb_stdout, set verbose to true.  */
+  static const bool verbose = false;
 
   class gdb_disassembler_test : public gdb_disassembler
   {
   public:
 
-    const bool verbose = false;
-
     explicit gdb_disassembler_test (struct gdbarch *gdbarch,
 				    const gdb_byte *insn,
 				    size_t len)