Re: [RFA] Environment variables passed to inferior by MinGW build (PR 10989)

Stan Shebs
2011-09-25T23:56:43Z

On 9/25/11 3:47 AM, Eli Zaretskii wrote:
> Ping! Ping! (2 weeks)

Seems uncontroversial to me (the previous discussion being about
entirely different issues). Let's put it in!

Stan
stan@codesourcery.com

>
>> Date: Mon, 19 Sep 2011 03:37:06 -0400
>> From: Eli Zaretskii<eliz@gnu.org>
>> Reply-to: Eli Zaretskii<eliz@gnu.org>
>>
>> Ping!
>>
>>> Date: Sun, 11 Sep 2011 08:33:25 -0400
>>> From: Eli Zaretskii<eliz@gnu.org>
>>> CC: Corinna Vinschen<vinschen@redhat.com>
>>>
>>> There's some history to this issue. It was discussed at least twice
>>> before:
>>>
>>> http://sourceware.org/ml/gdb-patches/2010-05/msg00317.html
>>> http://sourceware.org/ml/gdb-patches/2011-04/msg00347.html
>>>
>>> The first discussion simply died because the OP never responded to
>>> Joel's request to clean up the patch from weird characters.
>>>
>>> As for the second discussion, upon re-reading it I can only assume
>>> that there was a misunderstanding of some kind, perhaps Pierre was
>>> talking about both the Cygwin and the native Windows builds, while
>>> Chris and Corinna replied only about the latter.
>>>
>>> In any case, the original problem is still there in the MinGW build of
>>> GDB 7.3, and it just bit me hard enough to sit down and solve it.
>>>
>>> The code in the patch below is simply taken from what was there before
>>> it was deleted by Corinna back in 2006, after removing from it
>>> everything that was Cygwin-specific. So I don't even think I can take
>>> credit for this code ;-)
>>>
>>> With that patch, I can add environment variables with "set
>>> environment", delete them with "unset environment", and the inferior
>>> gets the environment I meant it to have.
>>>
>>> OK to commit?
>>>
>>> 2011-09-11 Eli Zaretskii<eliz@gnu.org>
>>>
>>> * windows-nat.c (env_sort) [!__CYGWIN__]: Function restored from
>>> before the change on 2006-12-09.
>>> (windows_create_inferior) [!__CYGWIN__]: Restore code that
>>> generates the environment block for CreateProcessA, modulo the
>>> Cygwin-specific parts that are not needed here.
>>>
>>>
>>> === modified file 'gdb/windows-nat.c'
>>> --- gdb/windows-nat.c 2011-05-09 14:25:35 +0000
>>> +++ gdb/windows-nat.c 2011-09-11 12:26:41 +0000
>>> @@ -1951,6 +1951,17 @@
>>> *flags |= CREATE_NEW_CONSOLE;
>>> }
>>>
>>> +#ifndef __CYGWIN__
>>> +/* Function called by qsort to sort environment strings. */
>>> +static int
>>> +env_sort (const void *a, const void *b)
>>> +{
>>> + const char **p = (const char **) a;
>>> + const char **q = (const char **) b;
>>> + return strcasecmp (*p, *q);
>>> +}
>>> +#endif
>>> +
>>> /* Start an inferior windows child process and sets inferior_ptid to its pid.
>>> EXEC_FILE is the file to run.
>>> ALLARGS is a string containing the arguments to the program.
>>> @@ -1977,6 +1988,12 @@
>>> char *toexec;
>>> char *args;
>>> HANDLE tty;
>>> + char *w32env;
>>> + char *temp;
>>> + size_t envlen;
>>> + int i;
>>> + size_t envsize;
>>> + char **env;
>>> #endif
>>> PROCESS_INFORMATION pi;
>>> BOOL ret;
>>> @@ -2124,6 +2141,31 @@
>>> }
>>> }
>>>
>>> + /* CreateProcess takes the environment list as a null terminated set of
>>> + strings (i.e. two nulls terminate the list). */
>>> +
>>> + /* Get total size for env strings. */
>>> + for (envlen = 0, i = 0; in_env[i]&& *in_env[i]; i++)
>>> + envlen += strlen (in_env[i]) + 1;
>>> +
>>> + envsize = sizeof (in_env[0]) * (i + 1);
>>> + env = (char **) alloca (envsize);
>>> + memcpy (env, in_env, envsize);
>>> + /* Windows programs expect the environment block to be sorted. */
>>> + qsort (env, i, sizeof (char *), env_sort);
>>> +
>>> + w32env = alloca (envlen + 1);
>>> +
>>> + /* Copy env strings into new buffer. */
>>> + for (temp = w32env, i = 0; env[i]&& *env[i]; i++)
>>> + {
>>> + strcpy (temp, env[i]);
>>> + temp += strlen (temp) + 1;
>>> + }
>>> +
>>> + /* Final nil string to terminate new env. */
>>> + *temp = 0;
>>> +
>>> windows_init_thread_list ();
>>> ret = CreateProcessA (0,
>>> args, /* command line */
>>> @@ -2131,7 +2173,7 @@
>>> NULL, /* thread */
>>> TRUE, /* inherit handles */
>>> flags, /* start flags */
>>> - NULL, /* environment */
>>> + w32env, /* environment */
>>> NULL, /* current directory */
>>> &si,
>>> &pi);
>>>