view gcc/config/gcn/mkoffload.c @ 145:1830386684a0

gcc-9.2.0
author anatofuz
date Thu, 13 Feb 2020 11:34:05 +0900
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/* Offload image generation tool for AMD GCN.

   Copyright (C) 2014-2020 Free Software Foundation, Inc.

   This file is part of GCC.

   GCC is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published
   by the Free Software Foundation; either version 3, or (at your
   option) any later version.

   GCC is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
   License for more details.

   You should have received a copy of the GNU General Public License
   along with GCC; see the file COPYING3.  If not see
   <http://www.gnu.org/licenses/>.  */

/* Munges GCN assembly into a C source file defining the GCN code as a
   string.

   This is not a complete assembler.  We presume the source is well
   formed from the compiler and can die horribly if it is not.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "obstack.h"
#include "diagnostic.h"
#include "intl.h"
#include <libgen.h>
#include "collect-utils.h"
#include "gomp-constants.h"

const char tool_name[] = "gcn mkoffload";

/* Files to unlink.  */
static const char *gcn_s1_name;
static const char *gcn_s2_name;
static const char *gcn_o_name;
static const char *gcn_cfile_name;

enum offload_abi offload_abi = OFFLOAD_ABI_UNSET;

/* Delete tempfiles.  */

void
tool_cleanup (bool from_signal ATTRIBUTE_UNUSED)
{
  if (gcn_cfile_name)
    maybe_unlink (gcn_cfile_name);
  if (gcn_s1_name)
    maybe_unlink (gcn_s1_name);
  if (gcn_s2_name)
    maybe_unlink (gcn_s2_name);
  if (gcn_o_name)
    maybe_unlink (gcn_o_name);
}

static void
mkoffload_cleanup (void)
{
  tool_cleanup (false);
}

/* Unlink FILE unless requested otherwise.  */

void
maybe_unlink (const char *file)
{
  if (!save_temps)
    {
      if (unlink_if_ordinary (file) && errno != ENOENT)
	fatal_error (input_location, "deleting file %s: %m", file);
    }
  else if (verbose)
    fprintf (stderr, "[Leaving %s]\n", file);
}

/* Add or change the value of an environment variable, outputting the
   change to standard error if in verbose mode.  */

static void
xputenv (const char *string)
{
  if (verbose)
    fprintf (stderr, "%s\n", string);
  putenv (CONST_CAST (char *, string));
}

/* Read the whole input file.  It will be NUL terminated (but
   remember, there could be a NUL in the file itself.  */

static const char *
read_file (FILE *stream, size_t *plen)
{
  size_t alloc = 16384;
  size_t base = 0;
  char *buffer;

  if (!fseek (stream, 0, SEEK_END))
    {
      /* Get the file size.  */
      long s = ftell (stream);
      if (s >= 0)
	alloc = s + 100;
      fseek (stream, 0, SEEK_SET);
    }
  buffer = XNEWVEC (char, alloc);

  for (;;)
    {
      size_t n = fread (buffer + base, 1, alloc - base - 1, stream);

      if (!n)
	break;
      base += n;
      if (base + 1 == alloc)
	{
	  alloc *= 2;
	  buffer = XRESIZEVEC (char, buffer, alloc);
	}
    }
  buffer[base] = 0;
  *plen = base;
  return buffer;
}

/* Parse STR, saving found tokens into PVALUES and return their number.
   Tokens are assumed to be delimited by ':'.  */

static unsigned
parse_env_var (const char *str, char ***pvalues)
{
  const char *curval, *nextval;
  char **values;
  unsigned num = 1, i;

  curval = strchr (str, ':');
  while (curval)
    {
      num++;
      curval = strchr (curval + 1, ':');
    }

  values = (char **) xmalloc (num * sizeof (char *));
  curval = str;
  nextval = strchr (curval, ':');
  if (nextval == NULL)
    nextval = strchr (curval, '\0');

  for (i = 0; i < num; i++)
    {
      int l = nextval - curval;
      values[i] = (char *) xmalloc (l + 1);
      memcpy (values[i], curval, l);
      values[i][l] = 0;
      curval = nextval + 1;
      nextval = strchr (curval, ':');
      if (nextval == NULL)
	nextval = strchr (curval, '\0');
    }
  *pvalues = values;
  return num;
}

/* Auxiliary function that frees elements of PTR and PTR itself.
   N is number of elements to be freed.  If PTR is NULL, nothing is freed.
   If an element is NULL, subsequent elements are not freed.  */

static void
free_array_of_ptrs (void **ptr, unsigned n)
{
  unsigned i;
  if (!ptr)
    return;
  for (i = 0; i < n; i++)
    {
      if (!ptr[i])
	break;
      free (ptr[i]);
    }
  free (ptr);
  return;
}

/* Check whether NAME can be accessed in MODE.  This is like access,
   except that it never considers directories to be executable.  */

static int
access_check (const char *name, int mode)
{
  if (mode == X_OK)
    {
      struct stat st;

      if (stat (name, &st) < 0 || S_ISDIR (st.st_mode))
	return -1;
    }

  return access (name, mode);
}

/* Parse an input assembler file, extract the offload tables etc.,
   and output (1) the assembler code, minus the tables (which can contain
   problematic relocations), and (2) a C file with the offload tables
   encoded as structured data.  */

static void
process_asm (FILE *in, FILE *out, FILE *cfile)
{
  int fn_count = 0, var_count = 0, dims_count = 0, regcount_count = 0;
  struct obstack fns_os, vars_os, varsizes_os, dims_os, regcounts_os;
  obstack_init (&fns_os);
  obstack_init (&vars_os);
  obstack_init (&varsizes_os);
  obstack_init (&dims_os);
  obstack_init (&regcounts_os);

  struct oaccdims
  {
    int d[3];
    char *name;
  } dim;

  struct regcount
  {
    int sgpr_count;
    int vgpr_count;
    char *kernel_name;
  } regcount;

  /* Always add _init_array and _fini_array as kernels.  */
  obstack_ptr_grow (&fns_os, xstrdup ("_init_array"));
  obstack_ptr_grow (&fns_os, xstrdup ("_fini_array"));
  fn_count += 2;

  char buf[1000];
  enum { IN_CODE, IN_AMD_KERNEL_CODE_T, IN_VARS, IN_FUNCS } state = IN_CODE;
  while (fgets (buf, sizeof (buf), in))
    {
      switch (state)
	{
	case IN_CODE:
	  {
	    if (sscanf (buf, " ;; OPENACC-DIMS: %d, %d, %d : %ms\n",
			&dim.d[0], &dim.d[1], &dim.d[2], &dim.name) == 4)
	      {
		obstack_grow (&dims_os, &dim, sizeof (dim));
		dims_count++;
	      }
	    else if (sscanf (buf, " .amdgpu_hsa_kernel %ms\n",
			     &regcount.kernel_name) == 1)
	      break;

	    break;
	  }
	case IN_AMD_KERNEL_CODE_T:
	  {
	    gcc_assert (regcount.kernel_name);
	    if (sscanf (buf, " wavefront_sgpr_count = %d\n",
			&regcount.sgpr_count) == 1)
	      break;
	    else if (sscanf (buf, " workitem_vgpr_count = %d\n",
			     &regcount.vgpr_count) == 1)
	      break;

	    break;
	  }
	case IN_VARS:
	  {
	    char *varname;
	    unsigned varsize;
	    if (sscanf (buf, " .8byte %ms\n", &varname))
	      {
		obstack_ptr_grow (&vars_os, varname);
		fgets (buf, sizeof (buf), in);
		if (!sscanf (buf, " .8byte %u\n", &varsize))
		  abort ();
		obstack_int_grow (&varsizes_os, varsize);
		var_count++;

		/* The HSA Runtime cannot locate the symbol if it is not
		   exported from the kernel.  */
		fprintf (out, "\t.global %s\n", varname);
	      }
	    break;
	  }
	case IN_FUNCS:
	  {
	    char *funcname;
	    if (sscanf (buf, "\t.8byte\t%ms\n", &funcname))
	      {
		obstack_ptr_grow (&fns_os, funcname);
		fn_count++;
		continue;
	      }
	    break;
	  }
	}

      char dummy;
      if (sscanf (buf, " .section .gnu.offload_vars%c", &dummy) > 0)
	state = IN_VARS;
      else if (sscanf (buf, " .section .gnu.offload_funcs%c", &dummy) > 0)
	state = IN_FUNCS;
      else if (sscanf (buf, " .amd_kernel_code_%c", &dummy) > 0)
	{
	  state = IN_AMD_KERNEL_CODE_T;
	  regcount.sgpr_count = regcount.vgpr_count = -1;
	}
      else if (sscanf (buf, " .section %c", &dummy) > 0
	       || sscanf (buf, " .text%c", &dummy) > 0
	       || sscanf (buf, " .bss%c", &dummy) > 0
	       || sscanf (buf, " .data%c", &dummy) > 0
	       || sscanf (buf, " .ident %c", &dummy) > 0)
	state = IN_CODE;
      else if (sscanf (buf, " .end_amd_kernel_code_%c", &dummy) > 0)
	{
	  state = IN_CODE;
	  gcc_assert (regcount.kernel_name != NULL
		      && regcount.sgpr_count >= 0
		      && regcount.vgpr_count >= 0);
	  obstack_grow (&regcounts_os, &regcount, sizeof (regcount));
	  regcount_count++;
	  regcount.kernel_name = NULL;
	  regcount.sgpr_count = regcount.vgpr_count = -1;
	}

      if (state == IN_CODE || state == IN_AMD_KERNEL_CODE_T)
	fputs (buf, out);
    }

  char **fns = XOBFINISH (&fns_os, char **);
  struct oaccdims *dims = XOBFINISH (&dims_os, struct oaccdims *);
  struct regcount *regcounts = XOBFINISH (&regcounts_os, struct regcount *);

  fprintf (cfile, "#include <stdlib.h>\n");
  fprintf (cfile, "#include <stdbool.h>\n\n");

  char **vars = XOBFINISH (&vars_os, char **);
  unsigned *varsizes = XOBFINISH (&varsizes_os, unsigned *);
  fprintf (cfile,
	   "static const struct global_var_info {\n"
	   "  const char *name;\n"
	   "  void *address;\n"
	   "} vars[] = {\n");
  int i;
  for (i = 0; i < var_count; ++i)
    {
      const char *sep = i < var_count - 1 ? "," : " ";
      fprintf (cfile, "  { \"%s\", NULL }%s /* size: %u */\n", vars[i], sep,
	       varsizes[i]);
    }
  fprintf (cfile, "};\n\n");

  obstack_free (&vars_os, NULL);
  obstack_free (&varsizes_os, NULL);

  /* Dump out function idents.  */
  fprintf (cfile, "static const struct hsa_kernel_description {\n"
	   "  const char *name;\n"
	   "  int oacc_dims[3];\n"
	   "  int sgpr_count;\n"
	   "  int vgpr_count;\n"
	   "} gcn_kernels[] = {\n  ");
  dim.d[0] = dim.d[1] = dim.d[2] = 0;
  const char *comma;
  for (comma = "", i = 0; i < fn_count; comma = ",\n  ", i++)
    {
      /* Find if we recorded dimensions for this function.  */
      int *d = dim.d;		/* Previously zeroed.  */
      int sgpr_count = 0;
      int vgpr_count = 0;
      for (int j = 0; j < dims_count; j++)
	if (strcmp (fns[i], dims[j].name) == 0)
	  {
	    d = dims[j].d;
	    break;
	  }
      for (int j = 0; j < regcount_count; j++)
	if (strcmp (fns[i], regcounts[j].kernel_name) == 0)
	  {
	    sgpr_count = regcounts[j].sgpr_count;
	    vgpr_count = regcounts[j].vgpr_count;
	    break;
	  }

      fprintf (cfile, "%s{\"%s\", {%d, %d, %d}, %d, %d}", comma,
	       fns[i], d[0], d[1], d[2], sgpr_count, vgpr_count);

      free (fns[i]);
    }
  fprintf (cfile, "\n};\n\n");

  obstack_free (&fns_os, NULL);
  for (i = 0; i < dims_count; i++)
    free (dims[i].name);
  for (i = 0; i < regcount_count; i++)
    free (regcounts[i].kernel_name);
  obstack_free (&dims_os, NULL);
  obstack_free (&regcounts_os, NULL);
}

/* Embed an object file into a C source file.  */

static void
process_obj (FILE *in, FILE *cfile)
{
  size_t len = 0;
  const char *input = read_file (in, &len);

  /* Dump out an array containing the binary.
     FIXME: do this with objcopy.  */
  fprintf (cfile, "static unsigned char gcn_code[] = {");
  for (size_t i = 0; i < len; i += 17)
    {
      fprintf (cfile, "\n\t");
      for (size_t j = i; j < i + 17 && j < len; j++)
	fprintf (cfile, "%3u,", (unsigned char) input[j]);
    }
  fprintf (cfile, "\n};\n\n");

  fprintf (cfile,
	   "static const struct gcn_image {\n"
	   "  size_t size;\n"
	   "  void *image;\n"
	   "} gcn_image = {\n"
	   "  %zu,\n"
	   "  gcn_code\n"
	   "};\n\n",
	   len);

  fprintf (cfile,
	   "static const struct gcn_image_desc {\n"
	   "  const struct gcn_image *gcn_image;\n"
	   "  unsigned kernel_count;\n"
	   "  const struct hsa_kernel_description *kernel_infos;\n"
	   "  unsigned global_variable_count;\n"
	   "  const struct global_var_info *global_variables;\n"
	   "} target_data = {\n"
	   "  &gcn_image,\n"
	   "  sizeof (gcn_kernels) / sizeof (gcn_kernels[0]),\n"
	   "  gcn_kernels,\n"
	   "  sizeof (vars) / sizeof (vars[0]),\n"
	   "  vars\n"
	   "};\n\n");

  fprintf (cfile,
	   "#ifdef __cplusplus\n"
	   "extern \"C\" {\n"
	   "#endif\n"
	   "extern void GOMP_offload_register_ver"
	   " (unsigned, const void *, int, const void *);\n"
	   "extern void GOMP_offload_unregister_ver"
	   " (unsigned, const void *, int, const void *);\n"
	   "#ifdef __cplusplus\n"
	   "}\n"
	   "#endif\n\n");

  fprintf (cfile, "extern const void *const __OFFLOAD_TABLE__[];\n\n");

  fprintf (cfile, "static __attribute__((constructor)) void init (void)\n"
	   "{\n"
	   "  GOMP_offload_register_ver (%#x, __OFFLOAD_TABLE__,"
	   " %d/*GCN*/, &target_data);\n"
	   "};\n",
	   GOMP_VERSION_PACK (GOMP_VERSION, GOMP_VERSION_GCN),
	   GOMP_DEVICE_GCN);

  fprintf (cfile, "static __attribute__((destructor)) void fini (void)\n"
	   "{\n"
	   "  GOMP_offload_unregister_ver (%#x, __OFFLOAD_TABLE__,"
	   " %d/*GCN*/, &target_data);\n"
	   "};\n",
	   GOMP_VERSION_PACK (GOMP_VERSION, GOMP_VERSION_GCN),
	   GOMP_DEVICE_GCN);
}

/* Compile a C file using the host compiler.  */

static void
compile_native (const char *infile, const char *outfile, const char *compiler)
{
  const char *collect_gcc_options = getenv ("COLLECT_GCC_OPTIONS");
  if (!collect_gcc_options)
    fatal_error (input_location,
		 "environment variable COLLECT_GCC_OPTIONS must be set");

  struct obstack argv_obstack;
  obstack_init (&argv_obstack);
  obstack_ptr_grow (&argv_obstack, compiler);
  if (save_temps)
    obstack_ptr_grow (&argv_obstack, "-save-temps");
  if (verbose)
    obstack_ptr_grow (&argv_obstack, "-v");
  switch (offload_abi)
    {
    case OFFLOAD_ABI_LP64:
      obstack_ptr_grow (&argv_obstack, "-m64");
      break;
    case OFFLOAD_ABI_ILP32:
      obstack_ptr_grow (&argv_obstack, "-m32");
      break;
    default:
      gcc_unreachable ();
    }
  obstack_ptr_grow (&argv_obstack, infile);
  obstack_ptr_grow (&argv_obstack, "-c");
  obstack_ptr_grow (&argv_obstack, "-o");
  obstack_ptr_grow (&argv_obstack, outfile);
  obstack_ptr_grow (&argv_obstack, NULL);

  const char **new_argv = XOBFINISH (&argv_obstack, const char **);
  fork_execute (new_argv[0], CONST_CAST (char **, new_argv), true);
  obstack_free (&argv_obstack, NULL);
}

int
main (int argc, char **argv)
{
  FILE *in = stdin;
  FILE *out = stdout;
  FILE *cfile = stdout;
  const char *outname = 0, *offloadsrc = 0;

  progname = "mkoffload";
  diagnostic_initialize (global_dc, 0);

  if (atexit (mkoffload_cleanup) != 0)
    fatal_error (input_location, "atexit failed");

  char *collect_gcc = getenv ("COLLECT_GCC");
  if (collect_gcc == NULL)
    fatal_error (input_location, "COLLECT_GCC must be set.");
  const char *gcc_path = dirname (ASTRDUP (collect_gcc));
  const char *gcc_exec = basename (ASTRDUP (collect_gcc));

  size_t len = (strlen (gcc_path) + 1 + strlen (GCC_INSTALL_NAME) + 1);
  char *driver = XALLOCAVEC (char, len);

  if (strcmp (gcc_exec, collect_gcc) == 0)
    /* collect_gcc has no path, so it was found in PATH.  Make sure we also
       find accel-gcc in PATH.  */
    gcc_path = NULL;

  int driver_used = 0;
  if (gcc_path != NULL)
    driver_used = sprintf (driver, "%s/", gcc_path);
  sprintf (driver + driver_used, "%s", GCC_INSTALL_NAME);

  bool found = false;
  if (gcc_path == NULL)
    found = true;
  else if (access_check (driver, X_OK) == 0)
    found = true;
  else
    {
      /* Don't use alloca pointer with XRESIZEVEC.  */
      driver = NULL;
      /* Look in all COMPILER_PATHs for GCC_INSTALL_NAME.  */
      char **paths = NULL;
      unsigned n_paths;
      n_paths = parse_env_var (getenv ("COMPILER_PATH"), &paths);
      for (unsigned i = 0; i < n_paths; i++)
	{
	  len = strlen (paths[i]) + 1 + strlen (GCC_INSTALL_NAME) + 1;
	  driver = XRESIZEVEC (char, driver, len);
	  sprintf (driver, "%s/%s", paths[i], GCC_INSTALL_NAME);
	  if (access_check (driver, X_OK) == 0)
	    {
	      found = true;
	      break;
	    }
	}
      free_array_of_ptrs ((void **) paths, n_paths);
    }

  if (!found)
    fatal_error (input_location,
		 "offload compiler %s not found", GCC_INSTALL_NAME);

  /* We may be called with all the arguments stored in some file and
     passed with @file.  Expand them into argv before processing.  */
  expandargv (&argc, &argv);

  /* Scan the argument vector.  */
  bool fopenmp = false;
  bool fopenacc = false;
  for (int i = 1; i < argc; i++)
    {
#define STR "-foffload-abi="
      if (strncmp (argv[i], STR, strlen (STR)) == 0)
	{
	  if (strcmp (argv[i] + strlen (STR), "lp64") == 0)
	    offload_abi = OFFLOAD_ABI_LP64;
	  else if (strcmp (argv[i] + strlen (STR), "ilp32") == 0)
	    offload_abi = OFFLOAD_ABI_ILP32;
	  else
	    fatal_error (input_location,
			 "unrecognizable argument of option " STR);
	}
#undef STR
      else if (strcmp (argv[i], "-fopenmp") == 0)
	fopenmp = true;
      else if (strcmp (argv[i], "-fopenacc") == 0)
	fopenacc = true;
      else if (strcmp (argv[i], "-save-temps") == 0)
	save_temps = true;
      else if (strcmp (argv[i], "-v") == 0)
	verbose = true;
    }
  if (!(fopenacc ^ fopenmp))
    fatal_error (input_location, "either -fopenacc or -fopenmp must be set");

  const char *abi;
  switch (offload_abi)
    {
    case OFFLOAD_ABI_LP64:
      abi = "-m64";
      break;
    case OFFLOAD_ABI_ILP32:
      abi = "-m32";
      break;
    default:
      gcc_unreachable ();
    }

  gcn_s1_name = make_temp_file (".mkoffload.1.s");
  gcn_s2_name = make_temp_file (".mkoffload.2.s");
  gcn_o_name = make_temp_file (".mkoffload.hsaco");
  gcn_cfile_name = make_temp_file (".c");

  /* Build arguments for compiler pass.  */
  struct obstack cc_argv_obstack;
  obstack_init (&cc_argv_obstack);
  obstack_ptr_grow (&cc_argv_obstack, driver);
  obstack_ptr_grow (&cc_argv_obstack, "-S");

  if (save_temps)
    obstack_ptr_grow (&cc_argv_obstack, "-save-temps");
  if (verbose)
    obstack_ptr_grow (&cc_argv_obstack, "-v");
  obstack_ptr_grow (&cc_argv_obstack, abi);
  obstack_ptr_grow (&cc_argv_obstack, "-xlto");
  if (fopenmp)
    obstack_ptr_grow (&cc_argv_obstack, "-mgomp");

  for (int ix = 1; ix != argc; ix++)
    {
      if (!strcmp (argv[ix], "-o") && ix + 1 != argc)
	outname = argv[++ix];
      else
	{
	  obstack_ptr_grow (&cc_argv_obstack, argv[ix]);

	  if (argv[ix][0] != '-')
	    offloadsrc = argv[ix];
	}
    }

  obstack_ptr_grow (&cc_argv_obstack, "-o");
  obstack_ptr_grow (&cc_argv_obstack, gcn_s1_name);
  obstack_ptr_grow (&cc_argv_obstack,
		    concat ("-mlocal-symbol-id=", offloadsrc, NULL));
  obstack_ptr_grow (&cc_argv_obstack, NULL);
  const char **cc_argv = XOBFINISH (&cc_argv_obstack, const char **);

  /* Build arguments for assemble/link pass.  */
  struct obstack ld_argv_obstack;
  obstack_init (&ld_argv_obstack);
  obstack_ptr_grow (&ld_argv_obstack, driver);
  obstack_ptr_grow (&ld_argv_obstack, gcn_s2_name);
  obstack_ptr_grow (&ld_argv_obstack, "-lgomp");

  for (int i = 1; i < argc; i++)
    if (strncmp (argv[i], "-l", 2) == 0
	|| strncmp (argv[i], "-Wl", 3) == 0
	|| strncmp (argv[i], "-march", 6) == 0)
      obstack_ptr_grow (&ld_argv_obstack, argv[i]);

  obstack_ptr_grow (&ld_argv_obstack, "-o");
  obstack_ptr_grow (&ld_argv_obstack, gcn_o_name);
  obstack_ptr_grow (&ld_argv_obstack, NULL);
  const char **ld_argv = XOBFINISH (&ld_argv_obstack, const char **);

  /* Clean up unhelpful environment variables.  */
  char *execpath = getenv ("GCC_EXEC_PREFIX");
  char *cpath = getenv ("COMPILER_PATH");
  char *lpath = getenv ("LIBRARY_PATH");
  unsetenv ("GCC_EXEC_PREFIX");
  unsetenv ("COMPILER_PATH");
  unsetenv ("LIBRARY_PATH");

  /* Run the compiler pass.  */
  fork_execute (cc_argv[0], CONST_CAST (char **, cc_argv), true);
  obstack_free (&cc_argv_obstack, NULL);

  in = fopen (gcn_s1_name, "r");
  if (!in)
    fatal_error (input_location, "cannot open intermediate gcn asm file");

  out = fopen (gcn_s2_name, "w");
  if (!out)
    fatal_error (input_location, "cannot open '%s'", gcn_s2_name);

  cfile = fopen (gcn_cfile_name, "w");
  if (!cfile)
    fatal_error (input_location, "cannot open '%s'", gcn_cfile_name);

  process_asm (in, out, cfile);

  fclose (in);
  fclose (out);

  /* Run the assemble/link pass.  */
  fork_execute (ld_argv[0], CONST_CAST (char **, ld_argv), true);
  obstack_free (&ld_argv_obstack, NULL);

  in = fopen (gcn_o_name, "r");
  if (!in)
    fatal_error (input_location, "cannot open intermediate gcn obj file");

  process_obj (in, cfile);

  fclose (in);
  fclose (cfile);

  xputenv (concat ("GCC_EXEC_PREFIX=", execpath, NULL));
  xputenv (concat ("COMPILER_PATH=", cpath, NULL));
  xputenv (concat ("LIBRARY_PATH=", lpath, NULL));

  compile_native (gcn_cfile_name, outname, collect_gcc);

  return 0;
}