/* rustspec.c -- Specific flags and argument handling of the gcc Rust front end.
   Copyright (C) 2009-2023 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/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "opts.h"

// satisfy intellisense
#include "options.h"

/* This bit is set if we saw a `-xfoo' language specification.  */
#define LANGSPEC (1 << 1)
/* This bit is set if they did `-lc'.  */
#define WITHLIBC (1 << 2)
/* Skip this option.  */
#define SKIPOPT (1 << 3)

void
lang_specific_driver (struct cl_decoded_option **in_decoded_options,
		      unsigned int *in_decoded_options_count,
		      int *in_added_libraries)
{
  unsigned int i, j;

  /* The new argument list will be contained in this.  */
  struct cl_decoded_option *new_decoded_options;

  /* "-lc" if it appears on the command line.  */
  const struct cl_decoded_option *saw_libc = 0;

  /* An array used to flag each argument that needs a bit set for
     LANGSPEC or WITHLIBC.  */
  int *args;

  /* True if we saw -static.  */
  int static_link = 0;

  /* True if we should add -shared-libgcc to the command-line.  */
  int shared_libgcc = 1;

  /* The total number of arguments with the new stuff.  */
  unsigned int argc;

  /* The argument list.  */
  struct cl_decoded_option *decoded_options;

  /* The number of libraries added in.  */
  int added_libraries;

  /* The total number of arguments with the new stuff.  */
  int num_args = 1;

  /* Whether the -o option was used.  */
  bool saw_opt_o = false;

  /* The first input file with an extension of .rs.  */
  const char *first_rust_file = NULL;

  argc = *in_decoded_options_count;
  decoded_options = *in_decoded_options;
  added_libraries = *in_added_libraries;

  args = XCNEWVEC (int, argc);

  for (i = 1; i < argc; i++)
    {
      const char *arg = decoded_options[i].arg;

      switch (decoded_options[i].opt_index)
	{
	case OPT_l:
	  if (strcmp (arg, "c") == 0)
	    args[i] |= WITHLIBC;
	  break;

	case OPT_o:
	  saw_opt_o = true;
	  break;

	case OPT_static:
	  static_link = 1;
	  break;

	case OPT_static_libgcc:
	  shared_libgcc = 0;
	  break;

	case OPT_SPECIAL_input_file:
	  if (first_rust_file == NULL)
	    {
	      int len;

	      len = strlen (arg);
	      if (len > 3 && strcmp (arg + len - 3, ".rs") == 0)
		first_rust_file = arg;
	    }
	  else
	    {
	      // FIXME: ARTHUR: Do we want to error here? If there's already one
	      // file?
	      // How do we error here? Do we want to instead just handle that in
	      // the session manager?
	    }

	  break;
	}
    }

    /* There's no point adding -shared-libgcc if we don't have a shared
       libgcc.  */
#ifndef ENABLE_SHARED_LIBGCC
  shared_libgcc = 0;
#endif

  /* Make sure to have room for the trailing NULL argument.  */
  num_args = argc + shared_libgcc * 5 + 10;
  new_decoded_options = XNEWVEC (struct cl_decoded_option, num_args);

  i = 0;
  j = 0;

  /* Copy the 0th argument, i.e., the name of the program itself.  */
  new_decoded_options[j++] = decoded_options[i++];

  /* NOTE: We start at 1 now, not 0.  */
  while (i < argc)
    {
      new_decoded_options[j] = decoded_options[i];

      if (!saw_libc && (args[i] & WITHLIBC))
	{
	  --j;
	  saw_libc = &decoded_options[i];
	}

      if ((args[i] & SKIPOPT) != 0)
	--j;

      i++;
      j++;
    }

  /* If we didn't see a -o option, add one.  This is because we need
     the driver to pass all .rs files to rust1.  Without a -o option the
     driver will invoke rust1 separately for each input file.  FIXME:
     This should probably use some other interface to force the driver
     to set combine_inputs.  */
  if (!saw_opt_o)
    {
      generate_option (OPT_o, "a.out", 1, CL_DRIVER, &new_decoded_options[j]);
      j++;
    }

  if (saw_libc)
    new_decoded_options[j++] = *saw_libc;
  if (shared_libgcc && !static_link)
    generate_option (OPT_shared_libgcc, NULL, 1, CL_DRIVER,
		     &new_decoded_options[j++]);

  *in_decoded_options_count = j;
  *in_decoded_options = new_decoded_options;
  *in_added_libraries = added_libraries;
}

/* Called before linking.  Returns 0 on success and -1 on failure.  */
int
lang_specific_pre_link (void) /* Not used for Rust.  */
{
  return 0;
}

/* Number of extra output files that lang_specific_pre_link may generate.  */
int lang_specific_extra_outfiles = 0; /* Not used for Rust.  */