Re: [PATCH v5] Implement the ability to set/unset environment variables to GDBserver when starting the inferior

[Thomas Preudhomme <thomas dot preudhomme at foss dot arm dot com>]

Hi Sergio,

I noticed that the share-env-with-gdbserver.exp test you added is skipped if 
using a gdb stub. However the comment says the test is meaningless for 
native-gdbserver. Shouldn't the check also look whether this is a cross debugger?

Best regards,

Thomas

On 31/08/17 22:26, Sergio Durigan Junior wrote:
> On Thursday, August 31 2017, Simon Marchi wrote:
>
> > On 2017-08-31 22:49, Sergio Durigan Junior wrote:
> > > Changes from v4:
> > >
> > > - Applied Simon's patch to refactor the unittest.  Thanks, Simon!
> > >
> > >
> > > This patch implements the ability to set/unset environment variables
> > > on the remote target, mimicking what GDB already offers to the user.
> > > There are two features present here: user-set and user-unset
> > > environment variables.
> > >
> > > User-set environment variables are only the variables that are
> > > explicitly set by the user, using the 'set environment' command.  This
> > > means that variables that were already present in the environment when
> > > starting GDB/GDBserver are not transmitted/considered by this feature.
> > >
> > > User-unset environment variables are variables that are explicitly
> > > unset by the user, using the 'unset environment' command.
> > >
> > > The idea behind this patch is to store user-set and user-unset
> > > environment variables in two separate sets, both part of gdb_environ.
> > > Then, when extended_remote_create_inferior is preparing to start the
> > > inferior, it will iterate over the two sets and set/unset variables
> > > accordingly.  Three new packets are introduced:
> > >
> > > - QEnvironmentHexEncoded, which is used to set environment variables,
> > >    and contains an hex-encoded string in the format "VAR=VALUE" (VALUE
> > >    can be empty if the user set a variable with a null value, by doing
> > >    'set environment VAR=').
> > >
> > > - QEnvironmentUnset, which is used to unset environment variables, and
> > >    contains an hex-encoded string in the format "VAR".
> > >
> > > - QEnvironmentReset, which is always the first packet to be
> > >    transmitted, and is used to reset the environment, i.e., discard any
> > >    changes made by the user on previous runs.
> > >
> > > The QEnvironmentHexEncoded packet is inspired on LLDB's extensions to
> > > the RSP.  Details about it can be seen here:
> > >
> > >
> > > <https://raw.githubusercontent.com/llvm-mirror/lldb/master/docs/lldb-gdb-remote.txt>
> > >
> > > I decided not to implement the QEnvironment packet because it is
> > > considered deprecated by LLDB.  This packet, on LLDB, serves the same
> > > purpose of QEnvironmentHexEncoded, but sends the information using a
> > > plain text, non-hex-encoded string.
> > >
> > > The other two packets are new.
> > >
> > > This patch also includes updates to the documentation, testsuite, and
> > > unit tests, without introducing regressions.
> >
> > That version LGTM.
>
> Thanks for all the reviews.
>
> Pushed:
>    0a2dde4a321d2f7bd2ded9a558b9ae92892de0e2