Windows libibery: Don't quote args unnecessarily

We only quote arguments that contain spaces, \t or "
characters to prevent wasting 2 characters per
argument of the CreateProcess() 32,768 limit.
---
 libiberty/pex-win32.c | 46 +++++++++++++++++++++++++++++++++++++---------
 1 file changed, 37 insertions(+), 9 deletions(-)

Ah, that was my mail-client.

Patch is ok IMO.  I add Ian CC for a second look at it.

Cheers,
Kai

On Tue, May 6, 2014 at 11:56 PM, Ray Donnelly <mingw.android@gmail.com> wrote:
> We only quote arguments that contain spaces, \t or "
> characters to prevent wasting 2 characters per
> argument of the CreateProcess() 32,768 limit.

This is OK.

Thanks.

Ian


>  libiberty/pex-win32.c | 46 +++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 37 insertions(+), 9 deletions(-)
>
> diff --git a/libiberty/pex-win32.c b/libiberty/pex-win32.c
> index eae72c5..8b9d4f0 100644
> --- a/libiberty/pex-win32.c
> +++ b/libiberty/pex-win32.c
> @@ -340,17 +340,25 @@ argv_to_cmdline (char *const *argv)
>    char *p;
>    size_t cmdline_len;
>    int i, j, k;
> +  int needs_quotes;
>
>    cmdline_len = 0;
>    for (i = 0; argv[i]; i++)
>      {
> -      /* We quote every last argument.  This simplifies the problem;
> -        we need only escape embedded double-quotes and immediately
> +      /* We only quote arguments that contain spaces, \t or " characters to
> +        prevent wasting 2 chars per argument of the CreateProcess 32k char
> +        limit.  We need only escape embedded double-quotes and immediately
>          preceeding backslash characters.  A sequence of backslach characters
>          that is not follwed by a double quote character will not be
>          escaped.  */
> +      needs_quotes = 0;
>        for (j = 0; argv[i][j]; j++)
>         {
> +         if (argv[i][j] == ' ' || argv[i][j] == '\t' || argv[i][j] == '"')
> +           {
> +             needs_quotes = 1;
> +           }
> +
>           if (argv[i][j] == '"')
>             {
>               /* Escape preceeding backslashes.  */
> @@ -362,16 +370,33 @@ argv_to_cmdline (char *const *argv)
>         }
>        /* Trailing backslashes also need to be escaped because they will be
>           followed by the terminating quote.  */
> -      for (k = j - 1; k >= 0 && argv[i][k] == '\\'; k--)
> -       cmdline_len++;
> +      if (needs_quotes)
> +        {
> +          for (k = j - 1; k >= 0 && argv[i][k] == '\\'; k--)
> +            cmdline_len++;
> +        }
>        cmdline_len += j;
> -      cmdline_len += 3;  /* for leading and trailing quotes and space */
> +      /* for leading and trailing quotes and space */
> +      cmdline_len += needs_quotes * 2 + 1;
>      }
>    cmdline = XNEWVEC (char, cmdline_len);
>    p = cmdline;
>    for (i = 0; argv[i]; i++)
>      {
> -      *p++ = '"';
> +      needs_quotes = 0;
> +      for (j = 0; argv[i][j]; j++)
> +        {
> +          if (argv[i][j] == ' ' || argv[i][j] == '\t' || argv[i][j] == '"')
> +            {
> +              needs_quotes = 1;
> +              break;
> +            }
> +        }
> +
> +      if (needs_quotes)
> +        {
> +          *p++ = '"';
> +        }
>        for (j = 0; argv[i][j]; j++)
>         {
>           if (argv[i][j] == '"')
> @@ -382,9 +407,12 @@ argv_to_cmdline (char *const *argv)
>             }
>           *p++ = argv[i][j];
>         }
> -      for (k = j - 1; k >= 0 && argv[i][k] == '\\'; k--)
> -       *p++ = '\\';
> -      *p++ = '"';
> +      if (needs_quotes)
> +        {
> +          for (k = j - 1; k >= 0 && argv[i][k] == '\\'; k--)
> +            *p++ = '\\';
> +          *p++ = '"';
> +        }
>        *p++ = ' ';
>      }
>    p[-1] = '\0';
> --
> 1.9.2
>