[Lldb-commits] [PATCH] Add arbitrary command line flags to llgs/debugserver startup for local debugging

[Todd Fiala]

I'm going to put this in since I haven't heard any feedback on it.


On Tue, Jul 29, 2014 at 10:02 AM, Todd Fiala <todd.fiala at gmail.com> wrote:

> BTW - I'm using LLDB_DEBUGSERVER_* as the prefix because there are already
> some more-specialized environment variables for similar tasks that start
> with that prefix.  Over time I could see DEBUGSERVER just becoming
> synonymous with llgs/stub/debug monitor/nub.
>
>
> On Tue, Jul 29, 2014 at 9:59 AM, Todd Fiala <todd.fiala at gmail.com> wrote:
>
>> This patch accepts environment variables of the form:
>> LLDB_DEBUGSERVER_EXTRA_ARG_n
>>
>> where n starts with 1, and may continue nearly indefinitely (up through
>> std::numeric_limits<uint32_t>::max()).
>>
>> The code loops around, starting with 1, until it doesn't find one of the
>> environment variables.  For each one it does find defined, it appends the
>> environment variable's contents to the end of the debugserver/llgs startup
>> command line issued when the stub is started for local debugging.
>>
>> I am using this to add arbitrary startup commands to the llgs command
>> line for turning on additional logging.  For example:
>>
>> export LLDB_DEBUGSERVER_EXTRA_ARG_1="-c"
>> export LLDB_DEBUGSERVER_EXTRA_ARG_2="log enable -f /tmp/llgs_packets.log
>> gdb-remote packets"
>> export LLDB_DEBUGSERVER_EXTRA_ARG_3="-c"
>> export LLDB_DEBUGSERVER_EXTRA_ARG_4="log enable -f /tmp/llgs_process.log
>> lldb process"
>>
>> Patch follows...
>>
>> diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
>> b/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
>> index be90eb2..d67bbdb 100644
>> --- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
>> +++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
>> @@ -817,7 +817,25 @@ GDBRemoteCommunication::StartDebugserverProcess
>> (const char *hostname,
>>              ::snprintf (arg_cstr, sizeof(arg_cstr), "--log-flags=%s",
>> env_debugserver_log_flags);
>>              debugserver_args.AppendArgument(arg_cstr);
>>          }
>> -
>> +
>> +        // Add additional args, starting with
>> LLDB_DEBUGSERVER_EXTRA_ARG_1 until an env var doesn't come back.
>> +        uint32_t env_var_index = 1;
>> +        bool has_env_var;
>> +        do
>> +        {
>> +            char env_var_name[64];
>> +            snprintf (env_var_name, sizeof (env_var_name),
>> "LLDB_DEBUGSERVER_EXTRA_ARG_%" PRIu32, env_var_index++);
>> +            const char *extra_arg = getenv(env_var_name);
>> +            has_env_var = extra_arg != nullptr;
>> +
>> +            if (has_env_var)
>> +            {
>> +                debugserver_args.AppendArgument (extra_arg);
>> +                if (log)
>> +                    log->Printf ("GDBRemoteCommunication::%s adding env
>> var %s contents to stub command line (%s)", __FUNCTION__, env_var_name,
>> extra_arg);
>> +            }
>> +        } while (has_env_var);
>> +
>>          // Close STDIN, STDOUT and STDERR. We might need to redirect them
>>          // to "/dev/null" if we run into any problems.
>>          launch_info.AppendCloseFileAction (STDIN_FILENO);
>>
>>
>> --
>> -Todd
>>
>
>
>
> --
> -Todd
>



-- 
-Todd
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