Re: [patch, sim, mips] Implement unlink, lseek, and stat for MIPS

[Steve Ellcey <sellcey at mips dot com>]

Ping.  The newlib/libgloss patch that this needs has been approved and
checked in.  OK to checkin this MIPS specific GNU simulator change?

Steve Ellcey
sellcey@mips.com


On Wed, 2013-07-10 at 07:48 -0700, Steve Ellcey wrote:
> A while back I submitted a GCC patch that allowed me to build the Fortran
> compiler on a newlib based cross compiler.  While using the GNU simulator
> to test that, I found that a number of tests failed due to unimplemented
> system calls on the MIPS GNU simulator.  This patch implements unlink,
> lseek, and stat in the GNU simulator for MIPS.  There is a second small
> patch that I sent to newlib that generates the necessary functions for
> the simulator to see and intercept these functions like it does others
> that are already implemented such as open and close.
> 
> OK to checkin?
> 
> Steve Ellcey
> sellcey@mips.com
> 
> 
> Steve Ellcey  <sellcey@mips.com>
> 
> 	* interp.c (sim_monitor): Add switch entries for unlink (13),
> 	lseek (14), and stat (15).
> 
> 
> diff --git a/sim/mips/interp.c b/sim/mips/interp.c
> index 032570a..766a113 100644
> --- a/sim/mips/interp.c
> +++ b/sim/mips/interp.c
> @@ -47,6 +47,7 @@ code on the hardware.
>  #include <ansidecl.h>
>  #include <ctype.h>
>  #include <limits.h>
> +#include <byteswap.h>
>  #include <math.h>
>  #ifdef HAVE_STDLIB_H
>  #include <stdlib.h>
> @@ -1342,6 +1343,60 @@ sim_monitor (SIM_DESC sd,
>  	break;
>        }
>  
> +    case 13: /* int unlink(const char *path) */
> +      {
> +	char *path = fetch_str (sd, A0);
> +	V0 = sim_io_unlink (sd, path);
> +	free (path);
> +	break;
> +      }
> +
> +    case 14: /* int lseek(int fd, int offset, int whence) */
> +      {
> +	V0 = sim_io_lseek (sd, A0, A1, A2);
> +	break;
> +      }
> +
> +/* We may need to swap stat data around before passing it on to the
> +   program being run.  */
> +#define copy16(x) (BigEndianMem ? bswap_16(x) : (x))
> +#define copy32(x) (BigEndianMem ? bswap_32(x) : (x))
> +
> +    case 15: /* int stat(const char *path, struct stat *buf); */
> +      {
> +	/* We need to put the data into the type of stat structure
> +	   that MIPS uses and make sure it has the correct endianness.
> +	   We are assuming that the host and MIPS agree on what the bits
> +	   in st_mode mean.  That appears to be true for x86 linux and
> +	   MIPS.  */
> +        struct stat host_stat;
> +	struct __attribute__ ((__packed__)) mips_stat {
> +		short st_dev;
> +		unsigned short st_ino;
> +		unsigned int st_mode;
> +		unsigned short st_nlink;
> +		unsigned short st_uid;
> +		unsigned short st_gid;
> +		short st_rdev;
> +		int st_size;
> +	} mips_stat;
> +	char *buf;
> +        char *path = fetch_str (sd, A0);
> +	buf = (char *) A1;
> +	V0 = sim_io_stat (sd, path, &host_stat);
> +	free (path);
> +	mips_stat.st_dev = copy16((short) host_stat.st_dev);
> +	mips_stat.st_ino = copy16((unsigned short) host_stat.st_ino);
> +	mips_stat.st_mode = copy32((int) host_stat.st_mode);
> +	mips_stat.st_nlink = copy16((unsigned short) host_stat.st_nlink);
> +	mips_stat.st_uid = copy16((unsigned short) host_stat.st_uid);
> +	mips_stat.st_gid = copy16((unsigned short) host_stat.st_gid);
> +	mips_stat.st_rdev = copy16((short) host_stat.st_rdev);
> +	mips_stat.st_size = copy32((int) host_stat.st_size);
> +	sim_write (sd, A1, (char *) &mips_stat, 20);
> +	break;
> +      }
> +
>      case 17: /* void _exit() */
>        {
>  	sim_io_eprintf (sd, "sim_monitor(17): _exit(int reason) to be coded\n");
>