Re: [PATCH] Check return value of bfd_init

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2018-10-26 11:41, Tom Tromey wrote:
>>>>>> "Tom" == Tom Tromey <tom@tromey.com> writes:
> 
> Tom> Moving the call to bfd_init below the call to "new ui" makes it 
> work.
> 
> Like so.
> 
> Tom
> 
> commit 2d0b2f3697a1f289e843f047697f252bf653d4db
> Author: Tom Tromey <tom@tromey.com>
> Date:   Thu Oct 25 09:00:52 2018 -0600
> 
>     Check return value of bfd_init
> 
>     Alan recently added a way for BFD library users to check whether 
> they
>     were in fact loading a compatible version of BFD:
> 
>     https://sourceware.org/ml/binutils/2018-10/msg00198.html
> 
>     It seemed reasonable to me that gdb should do this check as well, 
> in
>     case someone is dynamically linking against BFD.
> 
>     Simon pointed out that an earlier version of the patch would cause 
> a
>     gdb crash if the test failed.  This version works around this by
>     lowering the call to bfd_init and adding a comment explaining where
>     'error' can safely be called in captured_main_1.
> 
>     gdb/ChangeLog
>     2018-10-25  Tom Tromey  <tom@tromey.com>
> 
>             * main.c (captured_main_1): Check return value of bfd_init.
> 
> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
> index 61dc039d4fe..a90c2978185 100644
> --- a/gdb/ChangeLog
> +++ b/gdb/ChangeLog
> @@ -1,3 +1,7 @@
> +2018-10-25  Tom Tromey  <tom@tromey.com>
> +
> +	* main.c (captured_main_1): Check return value of bfd_init.
> +
>  2018-10-25  Andrew Burgess  <andrew.burgess@embecosm.com>
> 
>  	* python/py-function.c (convert_values_to_python): Return
> diff --git a/gdb/main.c b/gdb/main.c
> index 8709357e924..bf6a58180a0 100644
> --- a/gdb/main.c
> +++ b/gdb/main.c
> @@ -506,7 +506,6 @@ captured_main_1 (struct captured_main_args 
> *context)
>    textdomain (PACKAGE);
>  #endif
> 
> -  bfd_init ();
>    notice_open_fds ();
> 
>    saved_command_line = (char *) xstrdup ("");
> @@ -517,12 +516,17 @@ captured_main_1 (struct captured_main_args 
> *context)
>    setvbuf (stderr, NULL, _IONBF, BUFSIZ);
>  #endif
> 
> +  /* Note: `error' cannot be called before this point, because the
> +     caller will crash when trying to print the exception.  */
>    main_ui = new ui (stdin, stdout, stderr);
>    current_ui = main_ui;
> 
>    gdb_stdtargerr = gdb_stderr;	/* for moment */
>    gdb_stdtargin = gdb_stdin;	/* for moment */
> 
> +  if (bfd_init () == BFD_INIT_MAGIC)
> +    error (_("fatal error: libbfd ABI mismatch"));

The comparison operator is the wrong one (== instead of !=), you 
probably left it like this after testing.  LGTM with that fixed.

Simon