Re: [PATCH] Fix warning on gdb/compile/compile.c (C++-ify "triplet_rx")

[Simon Marchi <simon dot marchi at polymtl dot ca>]

On 2018-01-16 14:46, Sergio Durigan Junior wrote:
> This fixes a GCC warning that happens when compiling
> gdb/compile/compile.c on some GCC versions (e.g., "gcc (GCC) 7.2.1
> 20180104 (Red Hat 7.2.1-6)").
>
> It's a simple patch that converts "triplet_rx" from "char *" to
> "std::string", thus guaranteeing that it will be always initialized.
>
> I've regtested this patch and did not find any regressions.  OK to
> apply on both master and 8.1 (after creating a bug for it)?
>
> gdb/ChangeLog:
> 2018-01-16  Sergio Durigan Junior  <sergiodj@redhat.com>
>
> 	* compile/compile.c (compile_to_object): Convert "triplet_rx"
> 	to "std::string".
> ---
>  gdb/compile/compile.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/gdb/compile/compile.c b/gdb/compile/compile.c
> index 2ee75930ac..47646169c8 100644
> --- a/gdb/compile/compile.c
> +++ b/gdb/compile/compile.c
> @@ -463,7 +463,7 @@ compile_to_object (struct command_line *cmd, const
> char *cmd_string,
>    char **argv;
>    int ok;
>    struct gdbarch *gdbarch = get_current_arch ();
> -  char *triplet_rx;
> +  std::string triplet_rx;
>    char *error_message;
>
>    if (!target_has_execution)
> @@ -527,15 +527,15 @@ compile_to_object (struct command_line *cmd,
> const char *cmd_string,
>      }
>    else
>      {
> -      const char *os_rx = osabi_triplet_regexp (gdbarch_osabi 
> (gdbarch));
> -      const char *arch_rx = gdbarch_gnu_triplet_regexp (gdbarch);
> +      std::string os_rx = osabi_triplet_regexp (gdbarch_osabi 
> (gdbarch));
> +      std::string arch_rx = gdbarch_gnu_triplet_regexp (gdbarch);

Making these std::string makes unnecessary copies.

You can write the line below like this:

  triplet_rx = std::string (arch_rx) + "(-[^-]*)?-" + os_rx;

Otherwise, LGTM.

Simon