[PATCH v2] gdb: Copy inferior properties in clone-inferior

[Eli Zaretskii]

> Date: Thu, 16 Dec 2021 05:06:43 -0500
> From: Lancelot SIX via Gdb-patches <gdb-patches@sourceware.org>
> Cc: lsix@lancelotsix.com, Lancelot SIX <lancelot.six@amd.com>
> 
> Noticable Changes from V1:
>   - Fix and typos.
>   - Fix unfortunate use of c_str's value after free (in inferior.c).
>   - Remove unnecessary copies in for-loops by using const &.
>   - Reduce use of auto.
>   - Improve test naming (no capital, no "test" in name, better groups).
>   - Patch 2 on the original series has been dropped since it has no
>     immediate use..
> 
> Thanks Baris and Pedro for the reviews.
> 
> ---
> 
> This commit ensures that the following settings are cloned from one
> inferior to the new one when processing the clone-inferior command:
>   - inferior-tty
>   - environment variables
>   - cwd
>   - args
> 
> Some of those parameters can be passed as command line arguments to GDB
> (-args and -tty), so one could expect the clone-inferior to respect
> those flags.  The following debugging session illustrates that:
> 
>     gdb -nx -quiet -batch \
>          -ex "show args" \
>          -ex "show inferior-tty" \
>          -ex "clone-inferior" \
>          -ex "inferior 2" \
>          -ex "show args" \
>          -ex "show inferior-tty" \
>          -tty=/some/tty \
>          -args echo foo bar
>     Argument list to give program being debugged when it is started is "foo bar".
>     Terminal for future runs of program being debugged is "/some/tty".
>     [New inferior 2]
>     Added inferior 2.
>     [Switching to inferior 2 [<null>] (/bin/echo)]
>     Argument list to give program being debugged when it is started is "".
>     Terminal for future runs of program being debugged is "".
> 
> The other properties this commit copies on clone (i.e. CWD and the
> environment variables) are included since they are related (in the sense
> that they influence the runtime behavior of the program) even if they
> cannot be directly set using command line switches.
> 
> There is a chance that this patch changes existing user workflow.  I
> think that this change is mostly harmless.  If users want to start a new
> inferior based on an existing one, they probably already propagate those
> settings to the new inferior in some way.
> 
> Tested on x86_64-linux.
> 
> Change-Id: I3b1f28b662f246228b37bb24c2ea1481567b363d
> ---
>  gdb/NEWS                                  |  7 ++
>  gdb/doc/gdb.texinfo                       |  8 +-
>  gdb/inferior.c                            | 17 +++++
>  gdb/testsuite/gdb.base/inferior-clone.exp | 93 +++++++++++++++++++++++
>  4 files changed, 123 insertions(+), 2 deletions(-)
>  create mode 100644 gdb/testsuite/gdb.base/inferior-clone.exp

Thanks, the documentation changes are OK.