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

[Thomas Preudhomme <thomas.preudhomme@foss.arm.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
>