[RFA] win32-nat.c: Simplify generation of Windows environment

Corinna Vinschen
2006-12-07T09:58:50Z

Hi,

the below patch simplifies the code which translates the Cygwin
environment into the native Windows environment. So far this is
done in GDB manually. However, there's a Cygwin specific function
call which does the same for the calling process. Using this call
has three advantages.

- We can drop a rather big chunk of code from GDB which should be the
task of Cygwin anyway.
- By using the Cygwin method of converting the environment, we take
care of all environment variables which have to be converted in
some way; not only the PATH variable, but all variables which are
also translated by Cygwin, thus making this process more transparent.
- Subsequent changes in Cygwin don't require to change GDB.

Ok to apply?

Corinna

* win32-nat.c (env_sort): Remove.
(win32_create_inferior): Remove code which creates a Windows
environment. Use Cygwin function call instead. Propagate
current environment to inferior process.

Index: win32-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/win32-nat.c,v
retrieving revision 1.123
diff -u -p -r1.123 win32-nat.c
--- win32-nat.c 21 May 2006 23:04:39 -0000 1.123
+++ win32-nat.c 7 Dec 2006 09:56:15 -0000
@@ -1842,15 +1842,6 @@ win32_open (char *arg, int from_tty)
error (_("Use the \"run\" command to start a Unix child process."));
}

-/* 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);
-}
-
/* Start an inferior win32 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.
@@ -1918,83 +1909,7 @@ win32_create_inferior (char *exec_file,
strcat (args, allargs);

/* Prepare the environment vars for CreateProcess. */
- {
- /* This code used to assume all env vars were file names and would
- translate them all to win32 style. That obviously doesn't work in the
- general case. The current rule is that we only translate PATH.
- We need to handle PATH because we're about to call CreateProcess and
- it uses PATH to find DLL's. Fortunately PATH has a well-defined value
- in both posix and win32 environments. cygwin.dll will change it back
- to posix style if necessary. */
-
- static const char *conv_path_names[] =
- {
- "PATH=",
- 0
- };
-
- /* 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++)
- {
- int j, len;
-
- for (j = 0; conv_path_names[j]; j++)
- {
- len = strlen (conv_path_names[j]);
- if (strncmp (conv_path_names[j], in_env[i], len) == 0)
- {
- if (cygwin_posix_path_list_p (in_env[i] + len))
- envlen += len
- + cygwin_posix_to_win32_path_list_buf_size (in_env[i] + len);
- else
- envlen += strlen (in_env[i]) + 1;
- break;
- }
- }
- if (conv_path_names[j] == NULL)
- envlen += strlen (in_env[i]) + 1;
- }
-
- size_t envsize = sizeof (in_env[0]) * (i + 1);
- char **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);
-
- winenv = alloca (envlen + 1);
-
- /* Copy env strings into new buffer. */
- for (temp = winenv, i = 0; env[i] && *env[i]; i++)
- {
- int j, len;
-
- for (j = 0; conv_path_names[j]; j++)
- {
- len = strlen (conv_path_names[j]);
- if (strncmp (conv_path_names[j], env[i], len) == 0)
- {
- if (cygwin_posix_path_list_p (env[i] + len))
- {
- memcpy (temp, env[i], len);
- cygwin_posix_to_win32_path_list (env[i] + len, temp + len);
- }
- else
- strcpy (temp, env[i]);
- break;
- }
- }
- if (conv_path_names[j] == NULL)
- strcpy (temp, env[i]);
-
- temp += strlen (temp) + 1;
- }
-
- /* Final nil string to terminate new env. */
- *temp = 0;
- }
+ cygwin_internal (CW_SYNC_WINENV);

if (!inferior_io_terminal)
tty = ostdin = ostdout = ostderr = -1;
@@ -2024,7 +1939,7 @@ win32_create_inferior (char *exec_file,
NULL, /* thread */
TRUE, /* inherit handles */
flags, /* start flags */
- winenv,
+ NULL, /* environment */
NULL, /* current directory */
&si,
&pi);

--
Corinna Vinschen
Cygwin Project Co-Leader
Red Hat